Thai Journal of Operations Reseach : TJOR 2019-09-30T15:38:27+07:00 Associate Prof Dr.Kannapha Amaruchkul Open Journal Systems วารสารไทยการวิจัยดำเนิงาน Simulated Annealing for the Route Planning of Advisors in the RMUTL Cooperative Education Program 2019-09-17T07:28:40+07:00 Parida Jewpanya <p>The Rajamangala University of Technology Lanna (RMUTL) is Thailand's leading university in the field of science and technology. The university focuses on producing graduates who are ready for workplaces through a hands-on learning system. RMUTL incorporates a Cooperative Education Program (CO-OP) in the learning system which aims to gives students an opportunity to receive career training in industries. The students in the final academic year are required to attain this program for a semester to be prepared for the workplace. During the students’ internship period, the RMUTL CO-OP has a team of advisors who need to visit those students in the industries at least two times to give the students advice on their projects and working life. The current visiting plan is created based on the planner experience which sometimes ineffective in term of costs. Therefore, in this study, a mixed-integer linear programming model is formulated to help the planner find an optimal route for the advisors. The objective is to minimize the total cost of the advisor's visitation.&nbsp; Moreover, we propose a simulated annealing heuristic (SA) to solve the problem. We generate benchmark instances and solved them by SA. Computational results show the excellent performance of SA in terms of solution quality and computational efficiency.</p> 2019-09-17T07:28:19+07:00 ##submission.copyrightStatement## The Prediction of Surface Roughness in the S45C Medium Carbon Steel Turning Process by Using Response Surface Methodology 2019-09-30T15:37:32+07:00 Pongthorn Ruksorn <p>S45C medium carbon steel is increasing on demand due to it has been applied in various fields. The objective of the research was to study appropriate setting of parameters and the regression model for surface roughness prediction in the S45C Medium Carbon Steel Turning Process by using Box-Behnken experimental design. Three control factors were investigated including cutting speed, feed rate and depth of cut. The results indicated that the appropriate setting to minimize the surface roughness were cutting speed at 300 meter per minute, feed rate at 0.20 millimeter per round, depth of cut at 0.10 millimeter. The appropriate setting produced the surface roughness of 0.5477 micrometer and the composite desirability equals 0.98911.</p> 2019-09-30T15:37:31+07:00 ##submission.copyrightStatement## Nurse scheduling model by integer linear programming (A case study : The Fort Sunpasitthiprasong hospital) 2019-09-30T15:38:27+07:00 Ratee Bojaras <p>In this research, we formulate the model of nurse scheduling by using integer linear programming (A case study: The Fort Sunpasitthiprasong hospital). The objectives of the model are to maximize the number of nurse s’day-offs subject to the hospital’s rules with Lingo and compare to the head of nurse manually. The results show an effective scheduling because it satisfied all of the hospital’s rules with the maximum of nurse s’day-offs.</p> <p><strong>&nbsp;</strong></p> 2019-09-30T15:38:26+07:00 ##submission.copyrightStatement##