Chapter 566: The meaning of π

Chen Yijian saw Tan Zhenhua's face showing hesitation, thinking that he was worrying about the additional budget he was going to increase, so he couldn't help but sighed and said, "Zhenhua, I know that buying a computer is indeed an extra If the huge increase in investment is really difficult, it is not impossible for us to try to overcome it..."
Tan Zhenhua shook his head and said, "Master Chen, you are misunderstood. I don't want to pay this money. It's just that, as far as I know, high-performance computers are obviously in the restricted catalog of "Batumi". Thinking about how to buy these equipment."
Chen Yijian knew that he had misunderstood Tan Zhenhua. However, the question he raised was really troublesome. After thinking about it, he cautiously said: "Zhenhua, as far as I know, IBM is still willing to do business with us. As early as 1979, Hua Xia Bank purchased the first IBM computer—IBM3032. This computer was installed in Xiangjiang. It was also the first computer put into use in our Hua Xia Bank system. In the same year, they also I sold an IBM370/138 to our Shengjing Blower Factory, so I think, as long as I can find the right person, it is still possible to buy it, right?"
Tan Zhenhua smiled bitterly: "Master Chen, what you said is right. IBM is really willing to do business with us, but ah, they do business with us, but they choose people to do business with us. The two you just mentioned are not special. Advanced machines, as far as I know, are only tens of millions of operations per second, and they are still sold to our civilian units, but the fastest computers now have more than 200 million operations per second! Think, they must also stipulate certain restricted use clauses in the contract, and your 3603 is obviously a military scientific research unit. Whether they can sell it or not, and even if they are willing to sell, it is at best as outdated as you just mentioned. goods."
Chen Yijian sighed when he heard the words, "I also know that, so I asked you to find a way. Alas, if the super computer of Old Ci could come out sooner."
Chen Yijian's unintentional remarks immediately attracted Tan Zhenhua's attention, and the keyword he just said could not help but make him have endless reveries.
"Old Ci", in the computer field of China, can only be said to be a person, of course, this person is China’s first semiconductor transistor computer, the first integrated circuit computer with a million calculations per second, and set up for the China Intercontinental Missile Experiment. The prestigious "Yuanwang" measuring ship is equipped with the 151-3 / 4 type computer, the first real supercomputer, the chief designer of the "Galaxy I" supercomputer with billion operations per second, and the China Academy of Sciences Member of the Faculty, Ci Yungui.
Of course, the last computer that was enough to be included in the annals of China's history was still gestating in the current time and space, and even the name had not yet been determined.
Although Xiao Tan Tan didn't play IT in his previous life, he has heard of the great name of this computer.
He couldn't help asking: "Master Chen, what is going on with this computer? Can you tell me something?"
Chen Yijian rationalized his thoughts before replied: "Actually, I am not very clear because I am not in that business after all. I just heard that in 1978, the Grand Elder approved the development of my country's first supercomputer project. , And handed over this project to the National University of Defense Technology, with Professor Ci Yungui as the lead. The requirement at that time seemed to be 100 million operations per second, and the required time node seemed to be completed before the end of 1984."
Tan Zhenhua smashed his lips and said, "Billion times per second. Although this speed is not as good as the most advanced model in the United States, it is also a great achievement and breakthrough for China. If it is available now, I will bring it to you. It can also be used to solve the urgent need, but I don’t know how their progress is, what structure they have adopted, and whether they can be used to run the design assistance system I plan to buy for you."
Chen Yijian also accepted the words: "Although I am not very familiar with Old Ci, I have a few fate. I heard that his project was personally grasped by the final assembly. If you really care about this, Zhenhua If there is a chance, I will help you ask."
Tan Zhenhua replied: "Then please entrust Master Chen. I really care a little bit. To tell you the truth, I bought a British computer company a few days ago and took a small order by the way. Maybe, in the future There may be some cooperation."
Chen Yijian asked curiously: "Why did you buy a company here in Zhenhua? You are also a computer? Can you make the computer I want?"
Tan Zhenhua replied: "This, I'm afraid it won't work. My company can only produce some personal microcomputers, which are not of great use... By the way, it is okay to equip you with this machine. It's not very useful, but if you use it to do office document processing, you can barely get promoted...the special ones are still not good, there is no available Chinese system and input method."
Chen Yijian paused and said: "Zhenhua, what are your thoughts, even if it is a personal computer, it is a computer? It is better than us holding a slide rule. If nothing else, it is just a finite element. We use the Huaxia Academy of Sciences to calculate The calculation provided by the test software saves a lot of time than our manual calculation. As for the Chinese system and input method, that can be solved in a later step, as long as your computer can run the Fortran language compiler software normally!"
Tan Zhenhua immediately heard some unusual information from Chen Yijian's words. He asked: "Master Chen, listen to you, we have already had a finite element analysis calculation program in China?"
Finite element analysis, the English name FEA, is the abbreviation of FiniteElementAnalysis. It uses mathematical approximation methods to simulate real physical systems, especially geometry and load conditions. The biggest advantage is that simple and interactive elements can be used to approximate the real system of infinite unknowns with a limited number of unknowns.
Simply put, finite element analysis is to use simpler problems to replace complex problems before solving. It regards the required solution result as composed of many small interrelated sub-results called finite elements, and assumes a reasonable approximate solution for each element, and then derives the final result of the solution.
Because most practical problems in the engineering field do not actually require 100% accurate results, and in fact it is impossible to achieve 100%.
To give an example that is not too appropriate, for example, in mechanical processing, the design requirements stipulate that the size of a certain part is one meter, but in fact, due to the limitations of processing and measurement methods, no matter how high precision the machine tool is, It is possible to process parts with a size of exactly 1 meter, but can only be infinitely close to the theoretically required value. In actual work, the allowable tolerance range will be marked on the "1 meter" size on the drawing. , As long as the size of the processed part is within this tolerance range, it is a qualified product. Of course, this tolerance range will also affect some properties of the final product.
The finite element analysis is to take this error as a matter of course, but through a series of high-precision calculations, all aspects of its impact are considered, and finally it is within this error range, and the final production The range of possible performance of the parts out, so this method can not only effectively predict the final result, but also can adapt to various complex shapes, so it has become an effective engineering analysis method.
Chen Yijian listened to Tan Zhenhua’s question, frowned and recollected, and then replied: "Of course there is. I don’t remember the exact time very clearly. However, the application of finite element analysis in engineering is not new. It’s a matter of fact that the Western world began to use it a few centuries ago. For example, the infinite non-circular decimal number π, as we know it, is actually a classic case of finite element analysis. This is how to find the ratio of circumference to diameter. However, finite element analysis has been proposed as an engineering method, which is a recent thing. The first application is the structural strength calculation in the field of our aircraft, and because of its convenience, Practical and effective, it has rapidly expanded to almost all fields of science and technology, becoming a widely used, practical and efficient numerical analysis method."
After a pause, he sorted out his thoughts a bit and then said:
In our China, the research and application of finite element has actually started in the 1950s. Its initiator should be Professor Feng Kang, a member of the Institute of Mathematics. In 1965, he published a paper entitled "Difference Scheme Based on Variational Principles". This paper is regarded by the international academia as an important milestone and symbol of China's independent development of "Finite Element Method". Under his influence, China Academy of Sciences Several talented young people were found in the calculations. One of them put forward the idea of ​​using partial differential equations to solve finite elements in layers and practiced them. He wrote a set of finite element analysis software. I remember his achievement at that time. It seems that it was first applied to petroleum geological exploration. For this reason, he also won a major scientific and technological achievement award issued by the Ministry of Petroleum. The finite element analysis software we now use has evolved from then on."
Following Chen Yijian’s recollection, Tan Zhenhua felt that there was a certain piece of information in his memory that gradually overlapped with it. Although there seemed to be something missing, he had already remembered some of the most critical contents. After all, finite element analysis. This tool can also be regarded as one of the guys who ate in his previous life, and he still remembers the name and main author of the finite element analysis software he used frequently, because this is a domestic software, and among the software he commonly used, There are very few Huaxia people developed and can compete with similar foreign products, so he remembers this software very clearly.
So he couldn't help but blurt out and asked: "Master Chen, is the name of the finite element analysis software called FEPG, and that talented young man-oh no, he is probably not young anymore, he is Not Liang?"