my scientific age

Chapter 230 Asking is remorse and self-blame!
Hearing Professor Yang's name, all the first-year students followed Yang Wuzhi's gaze and fell on the seventh person in the classroom. Yu Hua, who suddenly became the focus of the crowd, was holding a pen in his right hand and was constantly writing mathematical characters on the scratch paper. A very focused expression.

"Yu Sheng." Looking at Yu Hua's focused appearance, Yang Wuzhi was not angry, he just shouted again.

Seeing this, the students sitting closest to Yu Hua quickly knocked on Yu Hua's desk.

"Uh...Professor Yang, you called me?" Yu Hua withdrew from his engrossed and efficient study on a daily basis, feeling embarrassed by the eyes of everyone, and asked.

Yang Wuzhi nodded: "Tell me about the definition of Lebesgue integral."

Hearing this question, and feeling the atmosphere in the classroom and the gazes of the students, Yu Hua still doesn't know the situation. As the first author of the paper on reconstructing Lebesgue integrals, he is familiar with Lebesgue integrals and can no longer be familiar with them. Then he started talking: "The definition of the Lebesgue integral is..."

From the definition of Lebesgue integral, to examples and applications, finally, Yu Hua concluded with the difference between Lebesgue integral and Riemann integral.

"The Lebesgue integral is summed by dividing the range of values, and the Riemann integral is summed by dividing the domain of definition. As a result, the Lebesgue integral is based on the Lebesgue measure theory, which is an extension of the Riemann integral. , and the significance of the Lebesgue integral itself is to reconstruct the fundamental theorem of calculus and lay the foundation for the birth of the discipline of real variable function theory, I have finished speaking, thank you." After Yu Hua finished his speech, he sat down again.

There was silence in the classroom.

The six seniors who entered the Mathematics Department earlier than Yu Hua by [-] semesters still looked confused. If the confusion just now was because Yang Wuzhi asked everyone to explain the definition of Lebesgue points, then the current confusion The pressure mainly comes from the crushing and unequal academic level.

To be fair, each word Yu Hua said was taken apart and listed separately. Whether it was Chinese or English, everyone present could read it.

God, what is the origin of this little boy?
"Mathematics requires hard work and talent. Obviously, you are neither hard enough nor talented. After more than ten years of perfecting Lebesgue points, the difficulty of learning has dropped a lot. Now there is only one month left until the end of the term. Think about it carefully, if you want to study, study hard, don't fish for three days and spend two days in the net. I also found that some of my classmates have a bad atmosphere and often go to the Eight Great Hutongs. I want to ask him if you are going to study mathematics with those Yao sisters. ?"

Yang Wuzhi glanced at the other students who were still confused, shook his head, and instead of continuing to lecture, he severely criticized: "Finally, if it is really difficult to learn, or you feel that you are not suitable for mathematics, then transfer to other majors as soon as possible. Don't delay your studies so you can't graduate."

Bad vibes.

This is the problem with these students in front of them.

From the perspective of a patriot, every Tsinghua student is a first-class patriot.

But from the perspective of a student, more than half of the seven first-year students in the Department of Mathematics are unqualified, either smoking or drinking, or prostitution and gambling.

To ask is to repent and blame oneself, and to persuade is to imitate Hu Shi.

This back-and-forth made Yang Wuzhi have a headache when he saw these students. Tsinghua University was strict and strict with students, and they could not graduate if they did not complete the credits. Among the more than ten departments in the school, the Department of Mathematics was the most difficult to learn.

Given the current situation of this batch of students, not to mention graduation, it is a good thing to be dismissed.

"I'm wrong, sir." The voice echoed in the classroom, and the six students below showed different expressions and reactions, and finally gathered to stand up and salute.

You know the shit. —— Looking at the familiar scene in front of him, Yang Wuzhi sighed in his heart. He didn't know when Chinese mathematics would flourish. He looked at Yu Hua, who was studying mathematical problems, and felt a little gratified and hopeful in his heart.

Yu Hua's talent in the field of mathematics is obvious to all, and it has long been spread to the professors of the Department of Mathematics. In terms of seniority, Yang Wuzhi is a well-deserved master. Although he and Hua Luogeng have different ideas, this is a matter between him and Hua Luogeng. , not about Yu Hua.

Yang Wuzhi is still very much looking forward to this math genius who is well-known in Tsinghua University and major universities.

"Sit down, let's continue the class." Yang Wuzhi motioned everyone to sit down, without disturbing Yu Hua, and continued to explain Lebesgue points.

Lebesgue points, the knowledge content of the first semester, Yang Wuzhi believed that Yu Hua was already familiar with it and could no longer be familiar with it, so he didn't want to disturb him too much.

In mathematics, the improvement of academic level mainly comes from self-understanding.

The master leads the door, and the practice is personal.

The class continued, but everyone in the audience turned their attention from time to time to Yu Hua, who was sitting alone, very curious about the identity and origin of this junior.

Yu Hua didn't pay attention to everyone's eyes, holding a pen in his right hand, and soon immersed himself in the study of discrete logarithms again.

Discrete logarithm is a very interesting integer problem. To understand discrete logarithm, we must first clarify the definition of logarithm. Logarithm is the inverse operation of exponentiation, just like division belongs to the inverse operation of multiplication, which means that for a given a and b, there is a number x such that bx=a.Similarly in any group G a power bK can be defined for all integer k.

The discrete logarithm refers to the integer k that makes bK=a, based on the congruence operation and a logarithmic operation of the original root.

Discrete logarithms can be quickly calculated in special cases. However, in most cases, there is no efficient calculation method, and modern cryptography is based on discrete logarithms, looking for solutions to discrete logarithms to establish encryption algorithms.

This is one of the three basic theories of modern cryptography.

After careful research, Yu Hua found that it is indeed very interesting. The properties and characteristics of discrete logarithms make it more suitable than other mathematical theories in the field of cryptography. It feels like discrete logarithms are born in cryptography. The field shines brightly.

On the draft paper, a series of complex numbers and English letters constitute the main body of the content. With the deepening of discrete logarithm research, Yu Hua already has an idea for the first set of encryption algorithms in the asymmetric era. These things on paper It is the framework and structure of the first set of encryption algorithms.

The foundation has been solid. After the framework and structure are established, Yu Hua can formally establish a set of encryption algorithms for asymmetric cryptography, allowing the world to enter the era of asymmetric cryptography.

"Ding!" Time passed slowly, and suddenly, a bell rang outside the classroom.

Hearing the bell, Yu Hua, who was concentrating on his research, once again quit his efficient study state. He felt a little bulging in his temples, a faint sense of dizziness came from his brain, and his energy had already been consumed. He shook his head gently: "In another week, it will be done Well, it really takes a lot of brains to do such serious math problems... Go to eat first, low blood sugar can't keep me in the best shape."

In the mind, the golden mathematical symbols continuously release the cold meaning, alleviating the discomfort under high-load operation.

It is undoubtedly painful for the human brain to engage in mathematical research. It is a process of finding and analyzing problems. To obtain the information entropy, the consumption is far greater than that of learning.

Some are dizzy and have low blood sugar. Yu Hua needs dry meals and rest to replenish himself.

(End of this chapter)