Great Country Academician

After seeing the two of them off, Xu Chuan returned to the second floor to pack his luggage.

If he followed his past habits, he would usually stay in his hometown until the 12th day of the new year before setting off.

After all, it is rare to come back a few times throughout the year. Spending time with parents and visiting relatives is something that must be done during the New Year.

However, this year's situation is special, so he is planning to leave on the sixth or eighth day of the lunar month.

Although I don’t know how far HiSilicon and Huaxin have advanced chip research, the international situation and the country’s desire for chips are indeed not optimistic.

When chatting with the two in the afternoon, Ding Jingguo, the leader of development and reform, mentioned these things more than once, especially after the realization of controllable nuclear fusion technology, the related situation and development have become more serious.

So Xu Chuan planned to end his vacation early and go to HiSilicon and Huaxin to check the situation.

If he can solve these mathematical problems and the country can make a breakthrough in chips, he will still be very happy.

After all, the development of science and technology has never been a matter of one person.

Just like the breakthrough of controllable nuclear fusion, it would not be possible without the efforts of other scientific researchers, engineers, and even security, construction and other grassroots workers.

In those areas that are easily overlooked by ordinary people, there are countless people struggling silently.

After saying goodbye to his parents, Xu Chuan took the high-speed train back to Jinling.

Outside the villa at the foot of Purple Mountain, under the leadership of Zheng Hai, a middle-aged man passed the security check with some anxiety and anticipation, and entered the villa that did not look outstanding.

"Academician Xu, the people from Huaxin have brought them here." Zheng Haihui reported in the living room.

Xu Chuan nodded and said with a smile, "Sorry to trouble you."

Zheng Hai: "I'm going out first. If anything happens, you can just call me at any time."

After saluting, Zheng Hai turned and left. In the living room, only the middle-aged man arranged by Xu Chuan and Hua Xin was left.

Seeing the figure sitting in the living room, the middle-aged man was a little nervous and apprehensive, but also looked forward to and admired him.

After all, this is the legendary figure. In terms of achievements, he is no different from the famous figures who are admired in history.

Xu Chuan didn't pay much attention. He glanced at the middle-aged man standing there nervously. He smiled and said, "Sit down first. Have you brought the data problem?"

"Hello, Academician Xu, my name is Mao Shun. I am the leader of the third group of Huaxin Technology R\u0026D Department. I am mainly responsible for mathematical design. This is the information you requested."

Hearing this, Mao Shun trembled, walked forward quickly, took out a small box from the backpack he carried with him, entered the password, took out a hard drive, and handed it to Xu Chuan respectfully.

Xu Chuan reached out and took the hard drive, looked at it twice, and said with a smile: "Do you understand all the mathematical problems in the hard drive?"

Mao Shun: “I don’t dare to say that I understand, but I understand most of them.”

This is also the main reason why the leader arranged for him to come here this time. His level is not high. In theory, if he wants to connect with this big boss, he should be a vice president-level figure at the end.

However, during the meeting yesterday, Mr. Ren from Warwick said that it would be best to arrange for someone who has knowledge of chip mathematical design to come over.

But when it comes to understanding mathematics, I am afraid that no one in the world dares to say that they understand mathematics in front of this big boss.

Looking at the entire history of mathematics, it is difficult to say where this expert ranks. But in this era, he is undoubtedly the number one person in mathematics.

"Then don't waste time and come with me." Xu Chuan nodded, got up and walked towards the study.

Solving the mathematical problems in chip design is something that should be done sooner rather than later.

Since the person in front of me, Mao Shun, knows something about it, let’s read it over before talking about it. If you have any questions, you can also ask him to explain it on the spot.

In the study, Xu Chuan connected the hard drive to his computer.

Instead of a laptop, he used a small supercomputer that Zheng Hai arranged for someone to build in the villa next door.

If his laptop might be hacked because it connects to the Internet to query papers and the like, then this specially built small supercomputer has basically no chance of being hacked.

This kind of thing related to the development of national chips should be paid attention to.

Clicking on the hard drive and entering the password, Xu Chuan found the question file that Mao Shun mentioned and read through it carefully.

Although he does not understand the circuit design and other fields in the chip, he still understands the basics of the operation of the chip or computer.

The foundation of computers is inseparable from three people. Leibniz invented binary, George Boole introduced Boolean algebra, and Shannon described switching circuits.

The combination of these three methods laid the foundation for the development of computers.

Binary is an algorithmic change of the decimal system. It is the basis for machine operation and the embodiment of the introduction of mathematics into life.

It is undoubtedly the lowest level of computers, because whether it is a simple or complex problem, it ultimately needs to be simplified into arithmetic operations to perform operations through logical switches.

The core is to use Boolean algebra to simplify all operations into AND or NOT operations of 0 and 1.

For example: when adding a+b, the carry is a\u0026b, and the 0 bit after the addition is (a\u0026!b) | (b\u0026!a). That is, AND, OR, and NOT can be used to express addition and subtraction.

Binary, combined with Boolean algebra, can represent all mathematical operations.

Claude Elwood Shannon brought "Symbolic Analysis of Relays and Switching Circuits", which brought binary and Boolean operations into reality through relays, laying the foundation for today's digital circuits.

Today, no matter how the integration of chips continues to increase, how the latest CPUs, GPUs, mobile phone processors and other devices are released, even the number of transistors has exceeded tens of billions.

But the mathematical logic running inside it is still the binary system proposed by Leibniz, the Boolean calculation invented by Boole, and the switching circuit described by Shannon.

Nothing has changed!

Of course, this is only the lowest foundation.

The actual calculations and designs in today's computer chips are much more complicated than this.

Including the information Xu Chuan will read now.

Although he doesn't know much about chip design, he does understand mathematics and modeling.

So he did not read through those mathematical problems immediately, but first learned some information through documents.

After all, if he doesn't even understand the situation, he can't possibly solve the problem.

This is just like to solve a mathematical problem, you must first understand the core point of the problem.

Through the information brought by Mao Shun, he had a general understanding of the ideas and progress of HiSilicon and Huaxin.

Judging from the data, the architecture of the seven-nanometer chips designed by these two companies is based on the ARM architecture.

The so-called Arm architecture is implemented by ARM for various micro-architectures to provide software compatibility architectures with various power consumption, performance and area combinations. It is one of the three strongest architectures for current processors (CPUs). .

Buying other people's infrastructure and then developing it is a very common thing in the chip industry.

Just like most scholars who study a difficult mathematical problem need to step on the shoulders of their predecessors and move forward.

After all, constructing your own method from beginning to end is still a very rare thing.

This is what HiSilicon and Huaxin do.

Through in-depth research on the ARM architecture, they continued to optimize and transform it, and established their own NPU neural network architecture.

The so-called NPU (embedded neural network processor/network processor) is a processor specially used for network application data packets. It is also a type of integrated circuit.

But unlike the single function of a special-purpose integrated circuit (ASIC), a neural networker is more flexible in handling more complex problems.

Generally, software or hardware can be specially programmed according to the characteristics of network operations to achieve special purposes of the network. Many different functions can be implemented on one chip to be applied to a variety of different network equipment and products.

The architecture designed by HiSilicon and Huaxin adopts a "data-driven parallel computing" approach and is relatively better at processing massive multimedia data such as videos and images than traditional methods.

It can be said that the blue is better than the blue.

However, the current architecture involves many systematic mathematical problems when constructing it, such as activation functions, two-dimensional data operations, decompression and other modules.

If it is in a conventional CPU or GPU chip, these problems are not difficult. However, the NPU neural network architecture is different in nature from the first two, and its mathematical compatibility is also completely different.

This results in the performance of the designed chips being even inferior to 10nm or even 14nm chips.

At present, the difficulty for card owners HiSilicon and Huaxin lies here.

Neural network and machine learning processing are still in the early stages of demand explosion. There are far fewer mathematicians in this field than traditional CPU/GPU architecture mathematicians. There are not many talents studying this field abroad, let alone domestic ones.

So out of necessity, the National Development and Reform Commission approached him, hoping that he could help solve this mathematical problem.

After understanding the overall situation, Xu Chuan clicked on the mathematics file and started browsing.

"Large-scale sparse matrix eigenvalue calculation"

"Overall Solution of Initial Value Problem of Nonlinear Ordinary Differential Equations"

"Initial value problem of first-order nonlinear time-delay differential equation under neural network architecture"

"NPU-based polynomial matrix eigenvalue parallelism"

"."

Question after question flashed through his eyes. There were not too many questions, not too few. There were about a dozen in total, and most of them were based on the difficulties born under the NPU neural network architecture.

Xu Chuan first clicked on the questions one by one and looked at them. From a mathematical basis, these questions were not difficult for him, but when it came to the NPU neural network architecture, he did not understand it very well.

If he wants to study it, he must first learn the NPU neural network architecture and understand the general outline, and then do it.

But that's not all. There are two or three math problems that he should be able to solve by now.

No matter how complex the mathematical problems involved in chip design are, they are just that difficult to him.

No matter how complicated the calculation method is, how complex the model structure and values ​​are, it cannot be more complicated than the high-temperature and high-pressure plasma turbulence model in controllable nuclear fusion, let alone be compared with the seven millennium problems.

In his view, having already solved two of the Seven Millennium Problems, describing these problems as the mathematics of a primary school student may be a bit exaggerated, but at most it is at the level of a college student.

Anyway, when he saw these problems, he already had ideas and methods to solve them in his mind.

After spending more than half an hour going through the entire document that Mao Shun brought over, Xu Chuan sat up straight, stretched, breathed a sigh of relief, and leaned on the chair to think.

Across the way, Mao Shun, who had been sitting in the study for a long time with his butt next to half of the chair, immediately cast an expectant look.

But before he could speak, Xu Chuan across from him took out manuscript paper and pen from the drawer, lowered his head again and began to get busy.

Seeing this, he forcefully swallowed the words that had reached his throat.

Opposite him, Xu Chuan ignored Mao Shun who was still sitting in the study. He quickly wrote down titles on the manuscript paper with the black pen in his hand.

[Stability analysis of stochastic time-delay differential equations driven by fractional Brownian motion]

"Some definitions of notation and function spaces. Let (Ω, F, P) be a complete probability space with a non-descending σ algebraic family {Ft}t≥0 that satisfies the usual conditions, that is, {Ft}t≥o is It is right continuous and Fo contains all P zero measurement sets. For all t\u003c0, let FL=Fo. The symbol |·| means "

"Then the time-fractional Sobolev space can be defined as its norm: Hs0 (D) = {U∈Hs (d), supp uD}"

"."

[High-precision calculation of eigenvalues ​​and singular values ​​of Vandermonde matrix]

"First given."

"."

In the study, Xu Chuan was busy solving problems.

Sitting at the desk opposite him, although it was not clear what the boss was studying, Mao Shun did not dare to disturb him and could only sit silently and wait.

Time passed like this bit by bit. In front of the desk, Xu Chuan had forgotten that there was another person in the room.

After writing the last line of calculations, he looked at the manuscript paper on the desk and touched his chin.

Three questions, that’s about it.

After clearing away the manuscript papers on the table, Xu Chuan followed his own process to check the answers to the questions.

Although problems of this level are not difficult for him, rigor is still essential.

After reviewing the answers on the manuscript paper, he nodded with satisfaction.

Okay, in theory there should be no problem.

Opposite me, Mao Shun, who finally waited for Xu Chuan to stop his calculations, thought for a moment, hesitated for a while, and finally plucked up the courage to ask: "Academician Xu, how do you feel?"

Xu Chuan sorted out the manuscript papers on the table and said, "I just took a quick look at it. Most of the problems in it involve your NPU neural network architecture, so I can't give you accurate answers for the time being. reply."

"But I have already solved the purely mathematical problems for you."

On the other side, after hearing this answer, Mao Shun was immediately confused and stammered: "What do you mean it has been solved for us?"

Xu Chuan smiled, stood up and walked to him holding the manuscript paper, handed him the manuscript paper, and said with a smile: "Literally, these manuscript papers are the process and answers. Although I haven't had time to sort and print them out, I think It’s almost the same, you can just take it back later.”

"As for other issues, I just took a look. Most of them are difficulties based on the NPU neural network architecture. I may need to study them."

Mao Shun took the manuscript paper with a confused look and turned it over. The white words were filled with various mathematical calculations.

Looking at the stack of manuscript paper in his hand, he couldn't help but swallow.

It seems that it hasn't been two hours since he walked into this villa, right?

I looked at the time on my watch, it was two thirty-four in the afternoon.

He could clearly hear the sound of his own swallowing. Mao Shun recalled that if he remembered correctly, he should have arrived on time at one o'clock.

Putting aside the time spent on security check, communication, and academician Xu’s reading of documents, it should only be about an hour, right?

It was really hard for him to describe this shock.

As the team leader in charge of mathematical design, he has come into contact with many domestic mathematicians in the past year, including many academicians of the Academy of Sciences.

But this problem that has not been solved for a year can be solved in one hour by this person?

Even if only one problem is solved, isn't this a bit too exaggerated?