Would you help me write this report better?

I not speak English. But I have a interview two days latter, and they ask me to make a three-minute self-introduce. The follow is what I prepare to say. Would you help me write this report better?
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Good morning. I am glad to be here for this interview. My name is lin yongpeng. Now, I am majoring in Computer Science. But I have studied in the department of mathematical science for one year before I was transferred to this department when I was a sophomore. Learning Mathematics and Computer Science is a great pleasure for me and they builds up my confidence. During the last three years, I have worked hard and I find that I am quite suitable for this field.
In the domain of computer science, I prefer software technology. I believe that I can make a great achievement in this aspect in the future with my enthusiasm and a sincere desire. That is why I choose Computer Science to further my study. It is very vital for me to continue my postgraduate study to broaden knowlegdge.
During the last summer, I took part in the Scilab Contest. Our team won the first prize. This brought me a lot of encouragement. For this summer, I am always busy in preparing the graduate Entrance Examination, missing the chance for mathematics modeling contest. If I can be recommended successfully, I will compete in the American undergraduate mathematical modeling contest held during the coming winter vacation without hesitate at the heart of my desires.
Thank you!

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Thank you very much!