Great Country Academician

In Xiaoxianzhuang, in the courtyard, Xu Chuan turned to look at the senior sister behind him.

"Sister, can you eat spicy food? Are there any taboos?"

When treating guests to dinner, there is no need to ask the guests what to eat when ordering food, just pay attention to the food taboos of the guests.

"I, I can do it."

Liu Jiaxin followed behind, looked at the courtyard of Xiaoxianzhuang, a little nervous and worried: "It must be very expensive here, why don't we go back to the school cafeteria to eat?"

She has never eaten at this kind of place, but she also knows that it should be expensive here.

Hearing this, Xu Chuan was a little ashamed, and said: "There is no one who treats guests to the school cafeteria, you go in first, I will come when I pick the fish."

After wandering around the courtyard for a while, Xu Chuan picked the best and most delicious fish with his vision of eating fish for many years, and asked the store to make one fish and three meals, added some vegetables and soup, and went into the inner hall.

"Huh? "Analysis and Research on Mathematical Modeling Competition Questions for College Students", are you going to participate in next year's college student modeling competition?"

Entering the inner hall, Xu Chuan saw a senior sister sitting in front of the window, holding a modeling textbook and reading it seriously.

Professor Zhou Hai mentioned this to him before and asked him to participate, but he refused. The previous IMO and IPHO can also be said to be for information security and to make up for regrets, but it is pure bullying to participate in the college student modeling competition. Yes, he still has face.

"Um."

Liu Jiaxin nodded lightly, hesitated for a moment, as if trying to muster up her courage, and then asked after a long pause, "May I ask you two math questions?"

The voice was very soft, as soft as a feather falling to the ground. If it weren't for Xu Chuan's good hearing, he almost didn't hear it.

"Of course you can. Besides, you can make your voice louder. No matter how small I am, I won't be able to hear you."

Xu Chuan joked with a smile. For him, he welcomes anyone who is willing to exchange mathematics and physics problems with him. Of course, as long as it is not those weird "civil science" problems.

Hearing Xu Chuan say that her voice was low, Liu Jiaxin lowered her head in embarrassment, but then, she opened her schoolbag again and took out a notebook from it.

"Well, that's really bothering you."

Liu Jiaxin opened the notebook, found her own question, and handed it to Xu Chuan.

"It's not troublesome. If you have any questions in the future, feel free to ask, but I may not be able to answer you about the mathematical knowledge of modeling."

Xu Chuan said something casually, and took the notebook casually. Looking at it, there were questions about mathematical modeling, as well as ordinary math questions, but the main ones were linear programming, random processes, and differential equations.

This is also normal, these problems are related to modeling.

"It's okay, I have studied some of these topics, I can talk about my own thoughts."

"Also, did you bring a pen? Let me tell you."

After reading the topic, Xu Chuan also heaved a sigh of relief. He didn't have a deep knowledge of modeling, but only had a rough understanding. Fortunately, he could understand and answer all the math problems in his notebook. It's a shame.

"Yes, yes."

Liu Jiaxin nodded quickly, took out a ballpoint pen from her schoolbag and handed it to him.

Xu Chuan took the ballpoint pen, turned to the blank page of the notebook, copied the previous first question, and then began to explain.

"This small question is expanded from the previous big question, and it is an extension of Model 2, which needs to describe the model dynamically."

"But don't be intimidated by the dynamic model. It sounds complicated, but in fact it is fundamental to establish a differential equation model and let your model change with time t, according to the second question"

"."

".Because of the need to analyze the sensitivity of rapid fluctuations, I can't simply look at the picture and talk. My analysis idea is to set the parameters related to the environment in the differential equation as variables with fluctuations, such as the humidity of the environment, and then evaluate the impact of each stage on the environment. Sensitivity to volatility."

"Its differential equation can be reduced to"

While explaining, Xu Chuan wrote down his core understanding, judgment process and corresponding simplified differential equations in his notebook.

The requirements for mathematical knowledge in college students' modeling competitions are far lower than those in college students' mathematics competitions. Generally speaking, mastering the basic mathematical knowledge necessary for modeling, such as advanced mathematics and calculus, is almost enough.

But it requires more computer knowledge and mathematical algorithms, such as Monte Carlo algorithm, graph theory algorithm, data fitting, parameter estimation, interpolation and other data processing algorithms

The difficulty of learning is not much lower than that of pure mathematics.

Because compared with pure mathematics, mathematical modeling is a very creative and challenging activity, and it is impossible to use some rules and regulations to specify how to build a model for various models.

It involves two aspects, first, transforming practical problems into theoretical models; second, calculating and analyzing theoretical models.

In terms of practicality, mathematical modeling is much higher than pure mathematics.

On the side, following Xu Chuan's explanation, Liu Jiaxin's eyes gradually brightened, and the shackles that had stuck her in her mind quickly collapsed with the ballpoint pen circulating on the notebook.

Occasionally, he followed Xu Chuan's explanation and asked one or two questions. After waiting for the precise answer and affirmation, his eyes became brighter.

"I said you are a really interesting couple. Other couples who come to dinner are all loving and loving. It's good for you to learn mathematics here."

Suddenly, a middle-aged woman's teasing voice with a smile rang in their ears.

She noticed this pair of young men and women just now. They should be students from Nantah University across the street. The girls came in and held the books to read. The classroom library began to explain the topic.

This is really interesting, she has worked in Xiaoxian Village for several years, and she has never seen anything like this.

Hearing the sound, Xu Chuan raised his head, and saw a middle-aged woman standing by the table holding a plate, putting the food on the plate one by one.

On the other side, Liu Jiaxin, who heard the teasing, blushed up to the ears, and her head couldn't stop lowering, almost into her chest.

Dazed for a moment, Xu Chuan felt a little embarrassed, coughed and said, "You misunderstood, we are just classmates."

The middle-aged woman smiled and shook her head, but did not continue: "Your dishes are ready, please confirm."

After the waiter left, Xu Chuan glanced at the senior, and said, "Well, let's eat first, and I will explain the rest of the questions to you after I return to school."