Confirm 1:

The writing of the paper is drawing to a close, and I have imagined what my mood will be like at this time countless times ... First of all, I would like to thank my tutor Professor Geng Guohua. Thank you for your all-round guidance, care and help in study, life and work. The teacher asked me to be a charming personality, be a famous teacher, be rigorous in my studies and grow up quickly, so that what I have learned can be used for a lifetime. How to express my lifelong gratitude with a simple "thank you"?

Secondly, I want to thank Professor Zhou. You are knowledgeable and humorous. You often generalize profoundly with simplicity, explain elegance with popularity, turn stone into gold, and turn decay into magic. Thank you for giving me the power of example.

Thanks again for the training of Northwest University. Thanks to the teachers of Information Technology College, your's teaching and theoretical support; Thanks to the brothers and sisters of the first three sessions and the last three sessions of the Institute of Visualization, we have gone through a journey together.

I would also like to thank the pioneers who reprinted and quoted data, materials, documents and research results. It is your previous research results that have given me a lot of inspiration, and some contents have provided operational guidance for the completion of the empirical aspects of the paper. The longer I write, the more I feel the need to learn. Thank you, without your previous efforts and achievements, there would be no smooth completion of my thesis.

Thanks to the leaders and colleagues of Xianyang Normal University, and thank you for the convenience you gave me during my study. Without your understanding and dedication, how could there be a happy ending today?

Finally, thank my family. I want to thank my daughter Shi in particular. My mother took you to Xida University, and you listened to combinatorial mathematics and oral English with her. When her study is boring, her work is cumbersome, and her cervical vertebra hurts, you bring her more relaxation than happiness.

There are many things to be thankful for, not all of which have names. Thank you for your words, your heart and your actions.

The paper is coming to an end, but this is not the end, on the contrary, it is a brand-new beginning.

Confirmation 2:

Learning itself is very difficult. When I was in primary school, my first teacher taught me Ye Shuai's poem, "You are not afraid of difficulties when you capture a city, but you are not afraid of difficulties when you capture a book. If there are obstacles in science, efforts can pass. " It is even more difficult to read a PhD, especially for my classmates (comrades-in-arms) who have left the university campus for more than ten years. To sum up, in recent years, I have had both pains and joys. Life is bitter, and the pursuit of pleasure. Lou, everybody out. I believe that these years of study and research experience will bring new changes and more opportunities to my future life.

During my blog, I received great support and selfless help from many teachers, classmates, relatives and friends. Here, I sincerely express my deep gratitude, thank you!

The teacher preaches, teaches and dispels doubts. I can't forget it, thanks to my tutor Professor Liu Juan. Over the past few years, the teachers' spirit of being conscientious, rigorous and advocating academics has been infecting me. From the careful guidance of all laboratory members in the weekly study seminar to the careful revision of each academic paper, it reflects the strict requirements and careful guidance of teachers to students. Teacher Liu gave detailed and valuable guidance in topics selection, research methods, technical route determination and thesis writing.

I would also like to thank Mr. Zhang Wen, Mr. Luo Fei and Brother Ni Bin who is far away in the United States. Thanks to Xiong Yi's brother and roommate Lu Lu badminton. They not only helped me a lot in my study and thesis writing, but also added a lot of fun to my life. Thanks to the teachers in the Graduate Management Office of Computer College, they have done a lot of tedious and necessary work!

Thank your parents for their support and concern. When I was in the most difficult time, my parents helped me and cared about me, giving me the motivation and confidence to move forward. Today's achievements are inseparable from their care, encouragement and support.

Special thanks to my wife and son. I have been studying PhD in Wuhan for several years. It is she who takes care of and educates her children.

To work hard, one shoulders the burden of family. Dear, thank you very much!

Thank everyone I know, my teachers, classmates, family, friends and relatives! Bless you!

Finally, I sincerely thank all the experts and professors who read this article and all the experts of the defense Committee for their hard work!

Acknowledgement 3:

On the occasion of the completion of this thesis, I would like to express my heartfelt thanks and respect to my tutor Professor Chen and my mistress Professor Zheng.

It is under the strict requirements and careful guidance of the tutor that the research work of this paper can be carried out smoothly. The tutor's rigorous academic attitude, keen observation ability, flexible thinking mode and solid professional skills have set an example for me to learn and will benefit me for life.

At the same time, I thank Mr. Zheng for his meticulous care of my study and life.

Here, I would like to extend my high respect and heartfelt thanks to them.

I sincerely thank Professor Dong Wenyong, Professor He Fazhi, Associate Professor Xiao, Associate Professor Zhao Jianhui and Associate Professor Wang Zhongyuan for their valuable guidance, help and advice in my study and work, which broadened my horizons and enhanced my confidence.

I sincerely thank Zheng, Li Kangshun, Ma Yong,,, and. Their communication has benefited me a lot, and I also thank them for their help and support in my study and life.

I sincerely thank experts and scholars for taking time out of their busy schedules to review my papers.

I sincerely thank my parents and family for their encouragement and support.

I sincerely thank all those who care about and support me.

Acknowledgement 4:

I will always remember seeing Mr. Liang for the first time at the end of September 2006 in the old computer college. At that time, I was deeply moved by Teacher Liang's attitude and passionate words. I met Mr. Liang several times later. Teacher Liang didn't neglect me, an ordinary student in a non-key college, and received me warmly every time, which made me unforgettable.

In the hot summer of 2007, I thanked Mr. Liang for making me his disciple and providing me with valuable conditions for further study. During the nearly four and a half years of studying for a doctorate, Mr. Liang's rigorous scientific attitude, tireless work style and spirit of selfless work for scientific research will always be an example for me to learn and benefit me for life. Teacher Liang is straightforward and open-minded. When I didn't do well, Mr. Liang pointed out my shortcomings and made me understand my own shortcomings and grow up. I also understand many valuable principles of being a man and correct my attitude towards scientific research. His love and care for me is beyond words, which fills my heart with gratitude. Teacher Liang is knowledgeable, sharp-minded and strict. In the process of writing this article, his advice can hit the nail on the head every time, which makes my mind suddenly clear. I can understand that his hard work is to train me to be a qualified doctor, so that I can truly show the important role of doctors when I go to work in the future, rather than becoming a social mediocrity. Thanks again to my tutor, Mr. Liang!

Thank you, Miss Dong Hongbin! Teacher Dong is rigorous and meticulous in his studies. Although I didn't get good grades after several doctoral dissertations, Mr. Dong patiently pointed out my shortcomings without any complaints, which made me gain something every time. Teacher Dong is affable, caring for students, and understands that I am a full-time student with little financial resources. She arranged a teaching assistant job for me, which not only improved my life, but also gained a piece of care from Teacher Dong.

Thanks to Tan Chengyu, the teacher of the research group, who is easy-going, serious and straightforward, and gave me very pertinent and practical advice on writing this article, which made me gain a lot. Thanks to brother Liu Sai of the research group, who sacrificed his lunch break and helped me revise my paper without complaint.

Thanks to the brothers and sisters who graduated and did not graduate from the laboratory for their concern and help. I am lucky to be a disciple of Teacher Liang and Teacher Dong with them!

I am grateful to my family for their meticulous care and support in spirit and material, so that I have no worries. In my most difficult time, it was their encouragement that gave me the courage to overcome all difficulties.

Finally, I once again express my heartfelt thanks to all the teachers, classmates and family members who have guided me, cared for me and supported me!

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