วารสารวิชาการเทคโนโลยีอุตสาหกรรม (J. Ind. Tech.) อยู่ในฐานข้อมูล TCI กลุ่ม 2 (2563) มีค่า JIF = 0.094 | The Journal of Industrial Technology (J. Ind. Tech.) is indexed in TCI Tier 2 (2020) with impact factor, JTIF 0.094

Articles

Effect of Thickness and Loading Rate on Mode I Fracture Toughness of Epoxy Resin

Machanical Engineering

Nowadays, polymer materials have begun to play a greater role in human life. Epoxy resin is one of the most widely used polymer materials because of its relatively high mechanical properties and can be easily molded due to its presence in the liquid state before forming. Epoxy resin has various used in many sections of industries due to its easily forming and making. A wide variety of applications result in different load characteristics or dimension of parts made from epoxy resin. In the use of parts made from epoxy resin or containing epoxy resin, it is found that the parts are mostly damaged under the lower load designed. Due to the design of those complex parts, it does not take into account the crack occur on the part. If the parts are complex, the important factor to consider is the fracture toughness of the material used to make the parts. Therefore, this research aims to study the fracture toughness of epoxy resin under mode I loading, which simulates a variety of applications by changing the range of variables, loading rates, and thickness of the specimen. For calculating the fracture toughness of epoxy resin, it is calculated using the finite element method. From the result, it was found that the loading rate and thickness of the specimen clearly affected the fracture toughness and fracture behavior of the epoxy resin under mode I loading.

Assessment of Wind Energy Potential in Thailand Based on Using the Multiple-Weibull Distribution

Machanical Engineering

Wind energy potential analysis is a design key to maximize wind turbine efficiency and annual energy output. Typically, the annual wind speed frequency is represented by a Single-Weibull distribution curve in spite of strong and calm wind patterns could occur through a year in many regions in the world, Thailand for instance. For this reason, wind energy potential should be analyzed by Multiple-Weibull distribution curves which are the representative of the meteorological seasons due to the monsoon’s effect. Therefore the objective of this study is to compare the accuracy of the Single-Weibull distribution and the Multiple-Weibull distribution in assessment of wind energy potential. The comparison was made between these two statistical distribution functions and the actual wind speed distribution (measured wind speed frequency) in order to determine the level of credibility of these two distribution functions. The wind speed data employed in this study was measured at Lamtakhong dam site in Nakhon Ratchasima province, Thailand. As the results, the error between the Single-Weibull distribution was 16.46% where the error between the Multiple-Weibull distribution was 14.82%, it was revealed that the smaller error, the higher reliability. Two of the most widely used wind turbines (Enercon E-30 and Windspot) were selected to verify the Multiple-Weibull concept. Approximately 40% increase in annual energy yield by using this method. So, the results confirmed that the Multiple-Weibull distribution is valid for the assessment of the annual energy production of wind turbines. Therefore, this will be a practical method for achieving the optimal design of stall-regulated wind turbine in the further work.

Cost Management Using ABC in the Wood Products Industry

Industrial Engineering

This research aimed to present the application of cost management system in the wood products industry. The case study is applied Activity-Based Costing (ABC) with a product of wooden stairs group, in order to determine the cost of production per unit which guided to cost reduction approach and compared with traditional costing methods. The production costs comprised of direct costs and indirect costs, including overhead costs. The factory had no appropriate cost allocation used for overhead cost because the traditional costing systems did not comply with actual production quantities and production times. This research then applied the ABC costing system and proposed applicable cost drivers with production activities to allocate overhead production costs. The proposed cost system was calculated using Microsoft excel. This work started from production costs and activities classification. The cost collection and cost evaluation systems were designed. Then, the activity value was analyzed and the cost drivers were determined for appropriated cost allocation criteria. After the costs of activities are calculated, the cost per unit of product calculation from the ABC cost system was compared to the traditional system. The new model of costs is more precise. As a result, the cost was reduced by 5.98%. The results also reflect non-value-added activities. This is important for executives to improve production efficiency and to manage production costs.

Blade Element Momentum Theory for Estimating Efficiency of Thai Sail Windmill

Machanical Engineering

Thai sail windmill (TSW) is a local machine of Thailand now using for pumping brine to the salt farms. TSW is a horizontal axis wind turbine that the blade is a triangular shape made of canvas. Traditional TSW efficiency is typically about 10-17%. However, it has been now developed and augmented its efficiency until 30-35%. Therefore, due to a low construction cost, an uncomplicated structure and a higher efficiency, these things encourage TSW more interesting for research. By the way, the wind turbine simulation is one significant research topic because the accurate simulation can bring about the evaluation of torque, power and efficiency correctly in another condition without the experiment. So, the simulation is very helpful to design the blade of the wind turbine. The purpose of this article is to perform the TSW simulation based on the blade element momentum theory to appraise the efficiency and to validate results with the experiment data. The efficiency evaluation would be regarded by 4 manners of the tip pitch angle as follows: 5, 10, 15 and 20 degrees. The results show that the TSW efficiencies estimated by the simulation are accurate at the tip pitch angle of 10, 15 and 20 degrees in the range of tip speed ratio of 2.0-3.5 whose average percentage error is about 7.0%.

Mathematic Model by Response Surface Methodology and Artificial Neural Network for Predict Result of Tensile Shear and Nugget Size of Zinc Coated Steel JIS G3313 Welded by Resistance Spot Welding

Machanical Engineering

This research described to the determine an optimization mathematic model using response surface methodology in central composite design method and artificial neural network (ANN) for predicting the of tensile shear and nugget size in the zinc coated steel JIS G3313. The following resistance spot welding (RSW) parameters were studied: the welding current, welding time, and electrode force. The resulting materials were examined using tensile shear tests which were observed nugget size and microstructure with scanning electron microscopy (SEM). The microstructure phenomenon could be explained by the welding optimum condition that fine pearlite and intensity in heat affected zone. The research results reveal that an optimum RSW parameters were welding current of 12 kilo amperes, welding time of 9 cycle and 1.5 kilo newton electrode force. The fine acicular ferrite occurred in the nugget size, which results in increased welding material high mechanical property. The ANN model with the proposed mathematical model, which tensile shear represents 3 neurons for the input 10 neurons for 1 hidden layer and 1 output neurons (3-10-1). The ANN model was developed to establish of the nugget predict represents 3 neurons for the input 5 neurons for 1 hidden layer and 1 output neurons (3-5-1). The mean square error (MSE) and coefficient of determination (R2) for tensile shear predict was showed that of 0.0026 and 0.956 respectively, which nugget size predicted MSE of 0.0004 and R2 of 0.958. This research, the related manufacturing sector can use research data and mathematical models was used to predict and quality control of the RSW processes to obtain tensile shear and the nugget size according to the acceptance criteria.

The Performance Improvement of Service Industry Supply Chain: A Case Study of Hotel in Sukhothai Province

Industrial Engineering

Hotel’s service industry has an important role toward economy and basic structures of transportation and tourism. Due to recent in competitive condition, hotel businesses must adapt and change in order to satisfy market’s needs by using internal resources of the organization to create usefulness and high efficiency. This study applied VSM technique to analyze and compare waste in Logistic management and hotel supply chain of two hotels as case studies in Sukhothai province, which were independent hotel and chain hotel along with applying Why Why Analysis and ECRS technique to improve efficiency by doing fieldwork to collect data, observing, and interviewing. The results after improving Hotels’ Logistics’ efficiency found that; case study 1 could reduce two NVA activities, which saved 7.15 minutes and was counted as 3.94% decrease, and one NNVA activity, which saved 5.10 minutes and was counted as 1.37% increase. This caused VA activity to increase for 1.37%; case study 2 could reduce two NVA activities and saved 5.20 minutes, which was counted as 0.31% decrease. This caused NNVA and VA activities to increase for 0.32% and 0.01% accordingly.

Comparison of Selection and Mutation in Genetic Algorithms for Examination Schedule Problem

Science

The purpose of this study is to present the comparison of selection and mutation in genetic algorithms to identify the most accurate parameter of examination schedule problem. Which includes 1) The group of students studying in the same course must take the same exam. 2) A student will have to take 1 examination at same time. 3) The number of students for each examination must not exceed the class capacity. 4) A proctor cannot supervise more than two sessions in the same day. 5) No student should have examinations on consecutive sessions. This study examined the selection based on three methods: Roulette Wheel Selection, Ranking Selection, and Tournament Selection. Similarly, three different methods were employed for mutation namely Swap Mutation, Insertion Mutation, and Inversion Mutation. In addition, the study investigated the most accurate parameter to determine the result by adjusting the probability of mutation, size of population, and the number of generations in the experiment. The result demonstrated that the most accurate parameter was from Tournament Selection and Swap Mutation where the probability of mutation is 75 %. The results showed that the Fitness Function average was 6,168 from 7,350. The experiment also revealed that the number of generations that provided the highest average Fitness Function was 365 generations.

Design and Developed Product the Kindergarten Classroom Furniture with Rubber Wood Using Quality Function Development

Industrial Engineering

This research is to apply a Quality Function Deployment (QFD) technique for designing and developing rubber wood furniture of a kindergarten classroom. The objective of this research is to design and create the classroom furniture by focusing on the shape and usability according to the user requirements. The methodology began with a survey in the kindergarten classroom instruction in order to specify of the sample groups. After that the user requirements were collected by using the designed questionnaires. The collected data from the questionnaires, such as the importance requirement scores, was calculated and then analyzed by the QFD technique. The analysis of QFD technique was divided in to two matrixes, including the furniture product planning matrix and the furniture part deployment matrix. The furniture product planning matrix was related to translate the user requirements to the technical requirements, while the furniture part deployment matrix was about the translation of the technical requirement to the part characteristics. The results of this research showed that the QFD technique was able to design and develop the shape and usability of the kindergarten classroom furniture that responded to the user requirements. The survey results from the users revealed that the average of satisfaction values in case of all new products were greater than that of the previous products from 3.437 scores to 4.373 scores, which increased approximately 22.23 percentage.

Arbitration in Administrative Construction Contract

Civil Engineering

The purpose of this research is to study administrative law, the practice of arbitration under the Arbitration Act B.E. 2545, foreign arbitration laws and the problems of arbitration in administrative construction contract of Thailand in comparison with foreign countries, namely Germany, France, England and the United States. This research emphasized on studying construction contract cases in which a party is a government agency and the private sector based on author experience in order to provide solution and recommendation for the development, improvement or amendment of Thailand administrative law related arbitration process. The research found that the main factors that make government still have to face problems arising from dispute resolution by arbitration and the dispute is proposed to administrative court causing consumption of time and financial expense is the lack of substantive and procedural laws for specifying the compulsory details in preparation of an arbitration agreement in administrative construction contact that is not yet comprehensive and still inadequacy. The comparison of foreign laws found that some countries have established rules for preparation of arbitration contract in addition to general principles included specification of subject matters of dispute that can be resolved by arbitration and maximum amount of money for which the arbitrator can order the parties to pay when the decision is made. Therefore, the study proposes to establish a new law for administrative construction contact with such criterions included.

A Study on Knowledge and Skills Essential for Work Safety in Automotive Factories

Machanical Engineering

The objectives of this study were to study the factors that affect the work safety of employees in the automotive parts manufacturing industry according to the supervisor opinion and study the knowledge and skills necessary to manage the safety in the operation of employees in the automotive parts production line. The samples were the supervisor of the production department of the automotive parts manufacturing industry in the areas of Rayong, Chonburi and Chachoengsao. Questionnaires and statistics used in the analysis were frequency, percentage, mean and standard deviation. The results showed that the factors that affect the safety of the employees in the automotive parts manufacturing industry as a whole were at a high level. (x􀴤 = 4.08) Including factors on each side, with an average of all levels, The most average aspect is the working environment. (x􀴤 = 4.23) The person with the lowest. (x􀴤 = 3.94) The knowledge and skills necessary for the supervisor to manage safely in the overall picture were at a high average. (x􀴤 = 4.00) Especially the knowledge of the operation is the highest average. (x􀴤 = 4.08) Which the skills of good leaders that the supervisor or the senior management must use a lot of technical skills including knowledge and expertise in the operations of that department to resolve problems with subordinates.

A System for Cooking Recipe Sharing and Cooking Recipe Finding by an Image of Ingredients using Deep Learning Technique

Electrical and Electronics Engineering

Nowadays, healthy eating is very popular. People start to cook their own food from existing cooking ingredients. However, sometimes they do not know what food can be cooked from existing ingredients. Therefore, they cook the same food, resulting in monotonous eating and not enjoy cooking. This research article presents the design and development of a system for cooking recipe sharing and cooking recipe finding by an image of ingredients using deep learning techniques. Users can use the application on mobile devices to share cooking recipes. Moreover, users can take a picture of ingredients that users already have in the kitchen such as garlic, pork, vegetables, etc. and send that picture into the system to search for cooking recipes from existing ingredients. This process will make users convenient for searching cooking recipes. The main components of the system include (1) A mobile application for general users developed with React Native, which users can add cooking recipes and search for cooking recipes by entering the ingredient names. Also, the user can use the mobile device to take a picture of ingredients to find cooking recipes, (2) Web application developed on the MERN stack for system administrators, which system administrators can add keywords of the search term for ingredients and test the model that has been created, and (3) Deep convolutional neural network using the YOLO algorithm through the Darknet library for creating the image recognition model. The model has taught to be able to recognize 20 types of ingredients using 100 images of each type of ingredient. After training our model for 36,000 rounds, the model has an average loss of 0.0408 with the precision, recall and F1-score at 0.96, 0.98 and 0.97 respectively.

Factors for Success for Online Business Entrepreneurs in the Digital Age

Electrical and Electronics Engineering

The objectives of this research were to: 1) study the success of online business entrepreneurs in the digital age; and 2) examine factors contributing to the success of online business entrepreneurs in the digital age. This research employed quantitative and qualitative research methodologies. In the quantitative research, the sample consisted of 260 online business entrepreneurs, obtained via multi-stage sampling. The sample size was determined based on 20 times the observed variables. Data were collected with the use of a questionnaire and analyzed with a structural equation model. For the qualitative research, in-depth interviews were conducted with 15 key informants including online business entrepreneurs and academic persons in the field of marketing. These informants were selected by purposive sampling. Data were analyzed with content analysis. The research findings showed that: 1) the success of the online business entrepreneurs was rated at a high level; 2) the characteristics of entrepreneurs, information technology, business strategies, and management innovation, all contributed to the success of online business entrepreneurs in the digital age with .05 level of statistical significance. Moreover, the findings also revealed an important point that entrepreneurs in the digital age needed to examine the needs of customers and respond to such needs promptly so that a marketing opportunity could be gained quickly. This could be done with the use of technologies in the digital age. Additionally, online entrepreneurs also needed to adjust their marketing strategies according to the market situations to ensure that they are competitive. They also needed to apply management innovation in the adjustment of business strategies to increase sales and expand their markets. These would align the business according to customer needs, leading to customer satisfaction, word of mouth communication among customers, repeat consumption, and brand loyalty. These findings can be used as guidelines for the development of success of online business entrepreneurs in the digital age by enhancing their potential in terms of marketing competitive advantage, creating and improving trading networks, and applying innovations and modern technologies in the development of their online businesses.

การปรับปรุงสายการผลิตชิ้นส่วนรถยนต์ด้วยเครื่องมือทางวิศวกรรมอุตสาหการ

Machanical Engineering

งานวิจัยนี้เป็นการศึกษาและปรับปรุงสายการผลิตชิ้นส่วนรถยนต์กรณีศึกษาสายการผลิต Power main A-Plat No.1 ซึ่งมีปริมาณการค้างส่งร้อยละ 16.50 จากการศึกษาปัญหาเบื้องต้นพบว่า การผลิตใช้เวลานานและมีขั้นตอนในการผลิตที่ยุ่งยากซับซ้อน จึงมีแนวคิดที่มุ่งเน้นเพื่อกำจัดความสูญเปล่าที่เกิดขึ้นในกระบวนการ การดำเนินการปรับปรุงเริ่มจากการศึกษากระบวนการผลิตโดยใช้เครื่องมือการศึกษาวิธีการทำงาน และการศึกษาเวลา ทำการจำแนกความสูญเปล่าที่เกิดขึ้นในกระบวนการทำงานตามหลักการความสูญเปล่า 7 ประการ จากนั้นใช้แผนผังก้างปลาในการวิเคราะห์หาสาเหตุของแต่ละปัญหา เพื่อนำไปใช้ในการปรับปรุงประสิทธิภาพการทำงานด้วยหลักการ ECRS ซึ่งผลที่ได้จากการปรับปรุงพบว่าเวลาในการทำงานสถานีงานที่ 1 ลดลงจากเดิม 17.27 วินาทีต่อชิ้น เหลือ 14.93 วินาทีต่อชิ้น คิดเป็นร้อยละ 13.55 และจากการปรับปรุงในสถานีงานที่ 2 มีเวลาการทำงานก่อนการปรับปรุง 19.21 วินาทีต่อชิ้น ลดลงเหลือ 15.70 วินาทีต่อชิ้น ประสิทธิภาพที่เพิ่มขึ้นร้อยละ 18.27 ส่งผลทำให้จำนวนชิ้นงานเพิ่มขึ้นจากเดิม 187 ชิ้นต่อชั่วโมง เป็น 220 ชิ้นต่อชั่วโมง มีค่าสมดุลการผลิตเพิ่มขึ้นจากเดิมร้อยละ 84.73 เป็น ร้อยละ 90.89 และปริมาณการค้างส่งลดลงจาก ร้อยละ 16.50 เหลือ ร้อยละ 13.22

Synthesis of Geopolymer From Water Treatment Residue and Palm Oil Fuel Ash

Civil Engineering

This research aimed at synthesizing the geopolymer of water treatment residue and palm oil fuel ash using proper suitable SiO2/Al2O3 ratios by varying the results of compressive strength test and also to examine the quality and microstructure of solidified waste cubes after the maximum of 60 days curing. In the test, the microstructure analysis techniques of XRF XRD SEM were employed. The findings revealed that the proper ratios of SiO2/Al2O3 in synthesizing geopolymer at 2.50 could develop geopolymerization reaction. (In SiO2/Al2O3 test were 1.77, 2.00, 2.50 and 3.00) It was also found that the synthetic geopolymer with optimum compressive strength at 40.56 Ksc. In employing the microstructure analysis technique of XRD and SEM, the changes inside geopolymer structure both before and after the mixing were found. The results can indicate the developing of geopolymerization reaction and synthetic geopolymer products inside the structure of Aluminosilicate source regarding the internal changes as follows; it was found that the peak of Quartz, Potassium Aluminum Silicate (KAlSi2O6), and X-rays diffraction had been superseded by the structure solid of Sodium Aluminum Silicate Hydrate (Na96Al96Si96O384.216H2O; NASH). It was also found Silicon, Aluminum, and Sodium at the same bonding position structure of NASH. As a result, the synthesis of the geopolymer of water treatment residue and palm oil fuel ash can developing strength and changing inside geopolymer structure by appear geopolymer product. Both starting materials can be synthesized and applied in environmental filed.

Students Techniques in Managing Stress at King Mongkut s Institute of Technology North Bangkok

Other

The purpose of this survey research is to study the level of students stress, factors affecting their stress, and techniques and problems in managing stress. The sample group was 478 undergraduate students at King Mongkut s Institute of Technology North Bangkok. A questionnaire including a stress assessment test from the Mental Health Department was employed in the data collection. The results showed that most students encountered stress in normal level (51.43%). The first factor affecting their stress was being unable to complete reading tasks on time (89.7%), the second was worry that they could not handle tests (89.5%), The methods used most frequently to cope with stress were watching movies, listening to music and watching television (97.5%), followed by making their mind calm, accepting the situations and letting go (90.2%). The problems in managing stress were their laziness and drowsiness (73.4%). The students who had different personal characteristics, learning problems , traffic problems and environment problems did not have different amount of stress. The students who had problems in terms of examination, their relationship with friends and lovers, family, health, money and work, and those who did not have these problems had different amount of stress with a statistical level of 0.05 .

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