Thanks to the guidance of Dr. Ra, with his help, my thesis was successfully completed. Dr. Ra is the best teacher I met in my 16 school career. First of all, according to my mathematical foundation and ability, Dr. Ra determined the topic, research objectives and methods of my graduation thesis, so that I could know the relevant theoretical knowledge as soon as possible. In the process of model design, data simulation, paper writing and revision, the teacher gave me careful guidance and help. Thanks to Dr. Ra for her tolerance, concern and easygoing. My oral English and listening comprehension are not very good. In every communication with the teacher, he always answers my questions patiently and takes pains to write down the matters that need special attention with a pen. Every time I review a paper, I always point out the shortcomings of the paper with an encouraging and tolerant attitude and give solutions. Dr. Ra was still very concerned about the progress of my thesis during the holiday.

Thank you, Dr. Sa, for your concern about the progress of my thesis writing when Teacher Ra was on a business trip.

Thanks to Dr. Ti and others for their help when I used Matlab program to simulate the model. Teacher Ma, thank you for correcting the grammar and vocabulary mistakes in my paper.

In addition, I am very grateful to Professor K for giving me this opportunity to continue studying abroad. My IELTS score is only 6, my major is accounting, and my math foundation is not very good. Professor K still sent me an unconditional admission notice.

Thanks to all the teachers who taught me the course during my one-year study in KK University, especially Dr. PP and Dr. ll. The average score of my previous courses was over 70, which is inseparable from your dedicated professors.

I am also very grateful to my parents and younger brother for their support in studying abroad.

Finally, I would like to express my heartfelt thanks to all the teachers who have been busy reviewing this article.

Thanks to Dr. Ra for guiding my thesis. With his help, my thesis was successfully completed. Dr. Ra is the best teacher I met in my study career in 16. Dr. Ra first determined my thesis topic, research objectives and methods for my mathematical foundation and ability, and let me know the relevant theoretical knowledge as soon as possible. Teachers have given me careful guidance and help in the process of model design, data modeling and paper writing and revision. Thank Dr. Ra for her tolerance, care and easygoing. My oral English and listening are not very good. In every course I communicate with my teacher, he always answers my questions patiently and pays special attention to writing them down with a pen. Every time I review my paper, I always point out the shortcomings of the paper with an encouraging and tolerant attitude and give solutions. Dr. Ra is still very concerned about the progress of my thesis during the holiday.

Thanks to Dr. Sarah's teacher for showing concern about the progress of my thesis when she was on a business trip.

Thanks to Dr. Ti and others. I use Matlab model simulation program to help. Thanks to Ms. Ma for her thesis on grammar, typos, etc. Change.

In addition, I am very grateful to Professor K for giving me the opportunity for further study. My IELTS score is 6, and I am not very good at accounting and mathematics in science at present. Professor K still sent me an acceptance letter unconditionally.

Thanks to the teachers of all the courses I have taught in KK University in the past year, especially Dr. PP and Dr. ll. The average score of my previous courses is over 70, and professors can't live without your heart.

I am also very grateful to my parents and my brother for their support in studying.

Finally, I would like to express my sincere thanks to the teacher for reading this article in spite of your busy schedule.