Happy New Year
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Two teachers and students in front of the self-related instrument: Wiener on the left, Li Yurong on the right, and Jerome Wiesner (then deputy director of the laboratory, later President Kennedy's scientific and technological adviser, and president of MIT) | 1949 at MIT
Written by | Wang Feiyue (Researcher, Institute of Automation, Chinese Academy of Sciences)
Responsible editor| Di Li Hui
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Li Yurong, born in Macau in 1904, is a native of Xinhui, Guangdong. He was the first Chinese to systematically study modern communication and control, and his work gave birth to Wiener's cybernetic thinking, and made great contributions to the later development of Wiener's cybernetic theory and engineering applications.
He received his Ph.D. from MIT in 1930 under the supervision of Wiener.
Wiener himself also attaches great importance to cooperation with Li Yurong, believing that Li Yurong's stability and judgment are exactly what he needs, Li Yurong is his "bridge" into engineering applications, and completed his first network patent with Li Yurong.
In fact, this is one of the main reasons why Wiener came to Tsinghua to teach for a year in 1936, because without Li, his research progress in circuit networks was greatly frustrated and he was helpless.
At Tsinghua University, they made more progress and deepened Wiener's understanding of the role of feedback, its meaning, and its complexity. They also put forward the idea of a discrete computer and arranged for Tsinghua University to purchase corresponding equipment and components from MIT, but for various reasons it was rejected by Bush, who was then the dean of the MIT School of Technology.
In addition, while at Tsinghua, Wiener also helped Hua Luogeng, going to England to study with his former teacher Hardy, making Hua Luogeng stand out in the international mathematical community.
Wiener himself believes that a year at Tsinghua University is the year when cybernetic ideas sprout.
In fact, Li Yurong was very difficult at the beginning of his studies with Wiener. In the beginning, designing circuits according to Wiener's theory always did not work. He ran to Wiener and said there must be something wrong with the theory. Fortunately, Li Yurong did not give up, kept trying, and after a year, he understood what Wiener was saying and finally succeeded.
Their "flexible network" was a revolutionary breakthrough at the time, so that "no one believed"!
Bose was Li Yurong's doctoral student, and he later relayed the hot scene of Li Yurong's doctoral dissertation defense.
All 20 professors in the electrical engineering department came, and they didn't understand what Li Yurong was doing, why they had a bunch of complex mathematical formulas for a clear circuit, and except for Wiener's assurance that these formulas were correct, Li Yurong himself couldn't tell what they meant.
It turned out that Lee, following Wiener's guidance, was the first to use the Laguerre function for circuit analysis, and for the first time used the term "Synthesis" common to circuits and controls today, and pioneered the Use of Hilbert transform relationships for engineering analysis, inventing the famous Lee-Wiener network.
Because he is not a mathematician, Li Yurong has not eaten through some places, and Weiner does not seem to spend much time thinking and guiding Li Yurong. As a result, everyone "slammed" Li Yurong and kept asking him questions, making him almost overwhelmed.
Finally, the young professor Wiener stood up and said, "Gentlemen, I suggest you take home your paper and study it well, and you will find that it is right!" Wiener's words ended Li Yurong's defense, but "passed" or "failed", no result.
Two weeks later, Li Yurong, in a state of anxiety, received a small note from the department that read, "You've passed." （You passed. ）”
Bosch was indignant about this, arguing that the professors owed Li Yurong and Wiener an apology: they should congratulate them and praise their great contribution, a landmark in the field of electrical engineering, which has since laid the theoretical and applied foundation for modern communication engineering.
After graduating with his Ph.D., Li Yurong had difficulty finding a job as a Chinese, although Wiener was very eager to keep him at MIT or work in the United States, and highly recommended him. In the end, Li Yurong had to return to Shanghai and then teach at Tsinghua University, and the first thing he had to do was to invite Wiener to visit China.
At Tsinghua, Wiener received a letter from AT&T asking to buy his and Li Yurong's patents. In order to make the patent available as soon as possible, Wiener decided to sell the patent at a low price of $5,000, thinking that the product would definitely get more profits after it was launched.
Unexpectedly, AT&T bought their patents to put them on the shelf, open up the market for their own patents, and eliminate competition. Since then, they have never received a penny from the patent. This incident made Wiener hate AT&T and large companies, and he began to lose trust in large organizations.
In early 1942, Wiener submitted to the military his study on anti-aircraft fire control entitled "Interpolation, Interpolation, and Smoothing of Steady-State Time Series." It's full of complicated mathematical formulas.
The report was quickly bound in a bright yellow cover by the head of the relevant department, Warren Weaver (also a mathematician), known as the "Yellow Peril" and marked as confidential, and circulated only among those with a certain classification.
In 1948, after the war, Shannon and Weaver published The Mathematical Theory of Communication (also a classic), which Wiener believed used his research to at least be inspired, while Wiener's report was not declassified until it was officially published in 1949.
Wiener, who had always believed that his theories could play an important role in World War II, was bureaucratically banned and has since lost faith in the government and military. This is one reason why he claimed after the war that he would no longer receive research grants from major corporations, the military and the government, and made a public anti-war statement, and why he wanted to go to Wright-Patterson Air Force Base but not go there himself.
From historical sources, Wiener was the happiest and most productive when working with low-key "insignificant" people such as Li Yurong and Bosch.
Wiener later helped Li Yurong find a place at MIT, but Li Yurong and his wife stayed in Shanghai due to the outbreak of the Anti-Japanese War, and finally survived by opening an antique shop and ata&T's patent fees. After the war, they were able to go to the United States, spared no effort to promote the application of Wiener theory at MIT, and achieved remarkable results, forming the world-famous school of communication statistics theory at that time, and held classes at MIT, and their lectures had a wide impact.
Many of Li's students, who remained at MIT to teach, were prominent authorities in the history of modern control and communications, and two of them founded Teledyne and Bose, which are still famous today. At this point, Li Yurong finally "returned" the "courtesy" of the professors of the Department of Electrical Engineering at MIT for his doctoral dissertation.
The MIT Summer Lectures hosted by Li Yurong made Wiener's theory widely disseminated and became the basis of modern communication | (photographed in 1954, Wiener was surrounded by Li Yurong and Shannon)
A second-generation Bengali-American, Bosch was a legendary student of Li Yurong and his first doctoral student.
At that time, Lee asked Bosch to study Wiener's papers and notes on nonlinear theory, but it took him ten months to figure out what Wiener was talking about. Every time he asked Li Yurong, Li Yurong always told him: "Insist, it will come." （Keep on it, it will come. ）”
Once Li Yurong told Bosch that there was an international conference on mathematics that would be held at MIT, and asked him to talk about Wiener's theory. Before that, Bosch had never made an academic report, and he didn't know what to say, and he was really frightened. Two weeks before the meeting, he finally felt "understood", and as a result, Bosch's report was highly praised by the conference, and even Wiener was very satisfied, and this experience became Bosch's most valuable learning experience.
There are three generations of teachers and students in front of the blackboard: Li Yurong on the left, Bosch in the middle, and Wiener | on the right In 1957 at MlT
At that time, Bos was depressed because it was difficult to sell his audio technology to large companies, and went to tell Li Yurong. Li Yurong used his experience in opening an antique shop to tell Bos: "The dream of every antique dealer is that one day an extremely valuable thing can come to his hand, and he can be recognized and grasped, and not let it run away." ”
Although Li Yurong did not say anything more, Persia understood: he should no longer go to a big company and do it himself! Today, Bose is the world's most famous audio equipment manufacturer, and Li Yurong is its "catalyst".
Li Yurong's life was simple and low-key, he was childless after marriage, his wife was Canadian, and he wrote A Letter to My Aunt, documenting his difficult experiences in China. He retired to California in 1969 and died on November 8, 1989. Today, Professor Li Yurong has almost completely forgotten, which is impressive.
Plate editing | Ginger duck