Chapter 78 Higher Education Society Cup National College Student Mathematical Modeling Competition teammates
Afternoon.
After eating and reading in the library for two hours, Wang Donglai got up and headed towards Yang Wanpeng's office.
This is the time when Yang Wanpeng gives guidance to students participating in the Higher Education Society Cup National Mathematical Modeling Competition.
Because Yang Wanpeng had told Wang Dong about his office before, Wang Donglai quickly found his office.
After entering, I found that there were two people already in the office.
Both are boys, and there is no girl.
"Classmate, are you also participating in the mathematical modeling competition?"
One of the boys, wearing glasses, proactively greeted Wang Donglai and said.
"Well, are you too?" Wang Donglai nodded in agreement and asked the two of them.
"Liao Qingfeng, a junior in the Department of Computer Science."
"Mathematics and Applied Mathematics, a junior, Ye Fei."
The two took the initiative to reveal their majors, and Wang Donglai also followed suit. professional classes Grade, "Qian Xuesen's mathematics experimental class, freshman, Wang Donglai."
"Are you Wang Donglai?"
"You were the one who caused such a big disturbance at the Terracotta Warriors and Horses two days ago?"< br>
Liao Qingfeng and Ye Fei obviously didn't expect that the person who appeared in front of them would be the person who caused quite a stir on the forum.
“Yes!”
Wang Donglai’s expression did not change and he responded calmly.
The atmosphere became cold, but it did not last long. Soon Yang Wanpeng opened the door and walked in.
Looking around, when he saw that everyone was here, he said aloud: "You should introduce each other. Next, the three of you will be in a team. I will not arrange the specific division of labor. Now, the three of you will discuss modeling, programming, thesis and defense, and divide the work according to your personal strengths.”
"But let me say one more thing, you three were specially selected by me. Liao Qingfeng's computer skills are pretty good, and Ye Fei's math skills are also pretty good. As for Wang Donglai, although he is only a freshman, he is no worse than you two. An SCI paper has been published, and the content of the paper is exactly Mathematics is related to big data algorithms and is very professional. At the same time, he is the top student in the liberal arts in the country. He is qualified for writing papers, defending, or anything else."
After saying this, Yang Wanpeng. Then he walked to his seat and turned on the office projector.
“In this National Mathematical Modeling Competition, I hope you can do your best and come back with a first prize.”
After saying this, a message appeared on the projector took a picture.
“This is the original question of the 2007 Mathematical Modeling Competition, National Population Growth Forecast. This question is not difficult, but it is a bit difficult to do it well. The more accurate it is, the higher the difficulty. , just for you to try.”
As he spoke, the PPT displayed on the projector began to turn.
“Our country is a country with a large population, and the population problem has always been one of the key factors restricting the development of our country. Since the comprehensive implementation of family planning in 1973, the fertility rate has dropped rapidly and has achieved world-renowned achievements. However, the comprehensive construction of Well-off society We will still face the demographic situation and severe test..."
"Please use mathematical modeling methods to analyze and predict our country's population based on existing data."
See. Wang Donglai instantly knew the answer to this question.
It was not entirely because he had the memory of more than ten years later, but also because of his mental arithmetic ability. At this moment, he quickly performed complex calculations on the given data and got the answer.
"What do you three think about this question?"
After Yang Wanpeng introduced this question, he stopped and asked the three of them.
Ye Fei first glanced at Wang Donglai, with a hint of hidden arrogance in his eyes, and took the initiative to say: "I think this question is very simple. First of all, the model hypothesis assumes that all factors that characterize and affect population change are Determined in the average sense of the entire social population."
"The birth and death levels are relatively stable during the forecast period, and even if there are changes, they are relatively regular."
"..."
"Assume that the prediction of future population is most likely to be in line with the future trend of population development."
"Then, it is dimensionless, using the initial value to transform the original data to eliminate the dimension, and use each indicator series of my country's population The 2001 data removes the original numbers behind According to the data, the multiple sequence is obtained, which is the initialized sequence. They are dimensionless and are all greater than zero. In this way, the sequence has something in common, which turns the problem to the analysis and comparison of the growth multiples of each factor in the original data, so as to solve the problem. is simplified. ""Denote a sequence after initialization as the parent sequence {X0. (t)}, and the remaining relevant factors are subsequences {X1(t)}, that is, at time t=k, the correlation coefficient between the parent sequence {X0(t)} and the subsequence {X1(t)} is... ”
“Among them, a∈[0, 1] is called Resolution coefficient. Obviously, the larger a is, the larger the resolution is. For simplicity, we take a=1. "
"For all points k=1, 2, A, n3, it is defined. The gray correlation degree between the comparison sequence X1 and the reference sequence X0 is..."
It has to be said that Ye Fei was very eloquent and seemed to have a well-thought-out answer. He explained the solution to this question just by dictating it.
After finishing speaking, Ye Fei glanced at Wang Donglai before sitting down.
Yang Wanpeng was noncommittal and did not comment. Instead, he looked at Liao Qingfeng and Wang Donglai, "Do you two have any opinions?"
"There is no problem with programming, it can be realized!" Liao Qingfeng was confident. replied.
"Well, I probably understand." Wang Donglai also roughly understood some modeling methods after Liao Qingfeng's answer.
Yang Wanpeng nodded, and the PPT was updated again.
"Look at the answers to this question by previous students, expand your thinking, and understand the key points of modeling."
The picture changes, and what is shown above is the past responses from students.
Seeing the above information, Wang Donglai shook his head invisibly.
Because the predicted data above is really far from the real situation.
In 2010, the national population was estimated to be about 1.35 billion.
In 2020, the national population is predicted to be 1.4 billion.
In 2025, the national population is predicted to be 1.42 billion.
In 2030, the national population is predicted to be 1.45 billion.
In twenty years, the population has increased by 100 million.
The population is only increasing, not decreasing, as if everyone has a strong desire to have children.
However, the actual situation may be that only Wang Donglai in this world knows the real situation.
“Mathematical modeling is actually very simple. It is to establish mathematical models based on actual problems, solve the mathematical models, and then solve practical problems based on the results.”
“ It is a kind of simulation, which is an abstract and brief depiction of the essential attributes of an actual subject using mathematical symbols, mathematical formulas, programs, graphics, etc. It may be able to explain certain objective phenomena, or it may be able to predict future development plans. Laws may provide an optimal strategy or a better strategy to control the development of a certain phenomenon.”
“In terms of programming, there are also several most commonly used software. You can use it yourself. Which one, Matlab, Mathematica, Lingo, SAS, you just need to pick one and get familiar with it, as long as it can answer the questions, even Excel will do.”
After Yang Wanpeng finished teaching the courseware, he said this to the three of them.
"Well, I have been exposed to Matlab and SAS before, and there is no problem!"
Liao Qingfeng said confidently.
"Well, next you should read more books by yourself, such as "Mathematical Model", "Mathematical Modeling Algorithm and Application", "Matlab Application in Mathematical Modeling", "SAS Common Statistical Analysis Tutorial" and so on You can read the books, and you can also find "Basic Tutorial on Mathematical Modeling" to understand.
"Although I am your instructor, I will not give you complete guidance. More. It still depends on your own learning and your own abilities. ”
"You can also try to do the questions I asked you to take before and practice more."
Yang Wanpeng said and packed up his things.
Seeing this, the three of them also stood up, agreed in unison, and resigned.
After leaving the office, Liao Qingfeng took the initiative and said to Wang Donglai: "Let's add a contact information first so that we can contact you if anything happens later."
Wang Donglai naturally would not refuse. , and exchanged contact information with Liao Qingfeng and Ye Fei.
After exchanging contact information, Ye Fei took the first step, but Liao Qingfeng suddenly said something to Wang Dong, which made Wang Donglai stunned.
Please support me. I have been in the hospital for the past two days. I can’t sleep well at all. My head is dizzy and I have a hard time typing. I hope everyone can support me. I can be discharged in a few more days... I’ll update it then. ! ! !
(End of this chapter)