# Oral-History:Michel Poloujadoff

## About Michel Poloujadoff

Michel E. Poloujadoff

Michel Poloujadoff was a French electrical engineer who was instrumental in the establishment of electrical engineering programs in France, Tunisia and Egypt. He spent a one-year fellowship at Harvard where he worked on the Aiken computer, returned to France to complete his doctorate. After serving in the French Air Force he commenced a lengthy teaching career at the University of Grenoble. This interview covers Dr. Poloujadoff's research and teaching, including his mentorship of numerous graduate students and his publication of textbooks on electrical engineering and motor mechanics that are used in universities throughout the world.

## About the Interview

MICHEL POLOUJADOFF: An Interview Conducted by Janet Abbate, Center for the History of Electrical Engineering, 25 July 1996

Interview #294 for the Center for the History of Electrical Engineering, The Institute of Electrical and Electronics Engineers, Inc.

## Copyright Statement

This manuscript is being made available for research purposes only. All literary rights in the manuscript, including the right to publish, are reserved to the IEEE History Center. No part of the manuscript may be quoted for publication without the written permission of the Director of IEEE History Center.

Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, IEEE History Center, 445 Hoes Lane, Piscataway, NJ 08854 USA or ieee-history@ieee.org. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

Michel Poloujadoff, an oral history conducted in 1996 by Janet Abbate, IEEE History Center, Piscataway, NJ, USA.

## Interview

Interview: Michel Poloujadoff

Interviewer: Janet Abbate

Date: July 25, 1996

### Education

Abbate:

Can you tell me a bit about your childhood and how you first became interested in Engineering?

Poloujadoff:

I don’t recall.

Abbate:

I see that you went to the Ecole Superieure d’Electricite. How did you decide to go there?

Poloujadoff:

I believed that electricity was something interesting at that time, and so why not?

Abbate:

Was that something many young men would be interested in?

Poloujadoff:

Well, I really don't know, because I was very good at Literature and that kind of thing. And Philosophy.

Abbate:

So you could have done those?

Poloujadoff:

Well, I surprised my professors that I was going to Engineering. I mean I surprised my professors of Literature, not my professors of Physics or Mathematics.

Abbate:

So you had to pick one. Then you went to Harvard, how did that come about?

Poloujadoff:

I wanted to see an exotic country.

Abbate:

So that was exotic.

Poloujadoff:

I believe this was my main purpose to see something a little strange and something else.

Abbate:

And was it?

Poloujadoff:

Yes it was.

Abbate:

At Harvard, did they seem to have a different focus? The engineering people there, from what you had seen in France, or was it the same?

Poloujadoff:

To go there, I needed a scholarship. To get the scholarship, I had to give a reason.

Abbate:

And what was your reason?

Poloujadoff:

In fact, something no American can understand. About the time I went to the States, I had begun already my Doctoral Thesis. In fact I didn't need a Masters Degree at all. So, the best reason I found to give to the Scholarship Committee was that I wanted to study computers.

Abbate:

Really?

Poloujadoff:

I invented many reasons for why this would be so great to help me finish my thesis. And I got the scholarship.

Abbate:

This was in the 1950s some time?

Poloujadoff:

It was the beginning of 1957.

Abbate:

What computers would you be using?

Poloujadoff:

A very large computer. Very, very powerful. I believe it had 1000 places, with 5 bytes each.

Abbate:

Was that the Aiken computer?

Poloujadoff:

Aiken was the head of the department.

Abbate:

Yes. I've seen that computer.

Poloujadoff:

Very, very charming man. Very impressive.

Abbate:

So, you were actually studying Computer Science?

Poloujadoff:

Yes.

Abbate:

Interesting. But you wanted to come back to France?

Poloujadoff:

Oh yes.

Abbate:

It was just a trip?

Poloujadoff:

Just a trip, nine months. And then I came back to finish my thesis as rapidly as possible, because afterwards I had to complete my military service. Vacations were finished.

### Military service

Abbate:

Were you doing engineering work in the military?

Poloujadoff:

Well, not really. I was with the mechanical engineering branch of the Air Force.

Abbate:

What does that mean?

Poloujadoff:

Well, mechanical engineering branch is the service which takes care of the planes. Maintenance mainly.

Abbate:

You weren't designing planes?

Poloujadoff:

No design, no.

Abbate:

So just service?

### Univ. of Grenoble professorship

Abbate:

Okay, then you went to Grenoble? You were teaching at the University?

Poloujadoff:

Then I was teaching at the University of Grenoble, for twenty-some years.

Abbate:

Can you tell me about that? How did you end up there?

Poloujadoff:

Well, because there were three positions for young professors open. It was an interesting position, the two other ones were not so interesting, or I could have chosen a position at a lower level. But at that level, only three positions were available in France in my specialty, so I decided to take that.

Abbate:

I talked to another engineer who had been at the University of Grenoble. Does it have a high reputation in Engineering?

Poloujadoff:

Oh yes.

Abbate:

So, is it, in terms of French universities, would that be one of the top ones?

Poloujadoff:

Oh yes. It is a very old university and it is in fact the first university in France where Electrical Power has been taught.

Abbate:

Really?

Poloujadoff:

Yes, by Paul Janet, who stayed there only for two years, I believe, or three years. He's also the founder of the École Supérieure d'Électricité in Paris.

Abbate:

Really. So, but he was at Grenoble first?

Poloujadoff:

He was in Grenoble first. So he started the teaching of Electrical Power Engineering. He's considered the starting point of what has been called for a long time, Institut Électrotechnique de Grenoble.

Abbate:

Is that separate from the University?

Poloujadoff:

No, that's very complicated. Very complicated. I believe probably it would take us far from your subject, the subject of the Engineering schools in France.

### History of engineering education in France

Abbate:

I would be interested a bit in the Engineering schools in France, because they are so different.

Poloujadoff:

It's probably something very particular in the world. In fact, the early French universities never admitted anything which was of low value. So, highest value was Theology. After that, I don't remember if it was Law or Medicine, but after those two Science was nothing. I believe Napoleon obliged the universities to teach Sciences.

Abbate:

I have heard that, yes.

Poloujadoff:

The first thesis in Sciences was submitted I believe around 1805. It was a thesis on mechanics. Afterwards, the universities still resisted Engineering. But the first Engineering schools date back to the middle of the Eighteenth Century. I believe the first larger Engineering school in France would have been École Polytechnique. That was founded outside the university. You know, not very long ago, a young man who is a mathematician...very recently, two months ago, a young man who is very brilliant, very brilliant mathematician, was introduced to another young man who is interested in Mathematics also, and he asked him, "What's your interest?" And he said, "Well, I am in numerical analysis of this and that." So the other one dropped the conversation.

Abbate:

Because that was...

Poloujadoff:

[Laughter] It's so disgusting. So, this explains why, in France, Engineering is mainly taught outside what we call universities. In Grenoble, the Institut National Polytechnique is now actually a university, but it is not called a university and also it doesn't have the first years of universities. There is no Freshman, no Sophomore in that university. You enter that kind of institution, after attending secondary schools, what you would call twelfth, thirteenth, fourteenth, fifteenth, sixteenth grade, I don't know exactly.

Abbate:

Closer to twelfth.

Poloujadoff:

But it really is the equivalent of university. Those classes they teach, Linear Algebra, Differential Analysis, Algebraic Geometry, all that stuff and at a very high level.

Abbate:

So there wasn't a separate university there in Grenoble?

Poloujadoff:

When I entered there, I was supposed to be a professor at the University, but I taught in fact in a separate school. Well, it's very complicated. It would demand several hours to explain it in detail.

### Teaching at the Univ. of Grenoble

Abbate:

So tell me about the work at the University. What were you teaching?

Poloujadoff:

I'm teaching mainly everything which is around electrical machinery. So this is a lot, because electrical machinery is applications of electro-magnetism. Electro-magnetism requires knowledge in Calculus, Numerical Analysis.

Abbate:

You taught all of that?

Poloujadoff:

Sometimes, yes...but some of my work is essentially numerical analysis. Not most of it, because I'm not a fanatic of this discipline. But sometimes, when I have a good subject, I like to make some numerical analysis.

### Numerical analysis

Abbate:

Can you give me an example of that?

Poloujadoff:

Of numerical analysis?

Abbate:

In some area that you worked on.

Poloujadoff:

When I was in Canada, I've been a one year visiting professor. In fact, I wasn't invited to be a professor, but I was in charge of starting a research program of defining the methods. The main point was to study the electro-magnetic field inside a transformer. So it was a problem of numerical analysis, with some experiments in parallel, because I always say, "Never try to compute anything if you don't know the answer by advance."

Abbate:

So you're simultaneously observing and developing theory?

Poloujadoff:

That's it.

Abbate:

How did you end up in, this was in McMaster University in Ontario, how did you come to teach there?

Poloujadoff:

One of the professors there is a former student of Grenoble. So he knew me and also he wanted somebody to start his research project, which was a very, very big project. He could ask only maybe one hundred people over the world to come. He had very little chances that somebody would be available. And I was.

Abbate:

What was this big project that he was starting?

Poloujadoff:

The eddy current losses in tank walls of large transformers to be accurate. In a very large transformer, those losses are very valuable. It would be necessary to explain the idea of capitalized price of the losses. If you have some apparatus, anyway, there are losses in apparatus. Generally, making it bigger would allow you to reduce the losses. But it would be more expensive. Now you have to find a compromise.

Abbate:

So you wanted a way to have less loss in a smaller transformer?

Poloujadoff:

No, that's not it. When you think of the problem, you try to think, "How much am I ready to pay to reduce the losses by so-many kilowatts?" This is called the price of the kilowatts. When you make your count, the eddy current losses in the tank walls of a transformer are a goldmine.

Abbate:

If you can reduce those?

Poloujadoff:

Yes, if you can reduce those, at a reasonable cost naturally. For that, you are obliged to have a good idea of the origin, exact origin, of those losses. It took four years, and some hundred thousand dollars to advance the solution to this problem. And apparently the project paid for itself before it was finished.

Abbate:

That's great. So were you working on the basic theory part or were you involved in the actual final project?

Poloujadoff:

No. The project was planned for four years, and I was there only for one year. What I was asked was to start the project. That's to say...well, what to do? Which methods? Which numerical methods to use? And I was very pleased. This is one of the times in my life where I was really very much interested in numerical analysis.

### Teaching techniques

Abbate:

In your teaching, it's not just theoretical what you're doing. At the same time, you have actual equipment that you're teaching students to use or hands-on things?

Poloujadoff:

Well, you cannot teach electrical machines without at least showing one!! Putting it into motion, making some measurements, because the most difficult task for a professor of Engineering in an amphitheater is to explain what he's talking about. Once the audience has understood what is the object the lesson, after that it's all easy. But their problem is, "What are you talking about?" That's very complicated. Because it's a very intricate system, and people don't realize what it is. You have definitely to organize laboratory sessions. Another problem is when you have to take them in the lab. Before the lecture, it may be too early. They see something, but they don't understand what it is. It's round. You have kinds of conductors. Well, if you push a button, it will run, they don't know why. So it's more or less useless. Now, if you take them to the lab too late, then they will realize too late what you were talking about. So, the choice of the time is very difficult. And in addition, you have plenty of various constraints, which are completely exterior to the teaching. Like availability of the equipment, availability of the staff, availability of the students, which complicate the problems. It's always very difficult to know when and where you will have to show the real thing and let them touch it.

Abbate:

Is that something you had to figure out over the years as you were teaching? Try one thing and another to...

Poloujadoff:

Oh, well you feel it when you are a student yourself. You don't know what the professor is talking about and you are trying to guess what it is and then you go to the lab and....well, electrical machines are very, very complicated things and the principle itself is very strange. In mechanics, you can understand that if you make an explosion, the volume will tend to expand, if you put a piston. Well, the piston will move, that's clear. If you put after the piston some arm, and you have a crankshaft, this you can understand rather easily, but electro-magnetic force is something you cannot guess. Nobody has ever seen a magnetic field. Nobody has ever seen an electric current. All you know is that if you put your fingers in the outlet, well, you will feel it. And you will not understand what happens. It's something you cannot imagine by itself.

Abbate:

That's interesting. Is that one of the things that interests you about Electrical Engineering?

Poloujadoff:

No, not really. Well, when you go farther, I must say that the operation of the internal combustion engine is also very mysterious and there are still hundreds of experiments every year, to discover more precisely how it works. So, you might suppose we know perfectly, after one hundred years, but we don't.

### Corporate consultant work

Abbate:

That's true. Was your work oriented toward electric power mostly, like generators? What kinds of equipment?

Poloujadoff:

Any kind of equipment. I was never interested in watch motors, for example, but I might have been. I have been a consultant, for example, to Moulinex, and I've been a consultant to appliance makers.

Abbate:

What did they want you to do?

Poloujadoff:

I would say to deepen their knowledge of electric meters. I told you, we still don't know how an automobile engine works to some extent, naturally. For the electric motors, it's the same. Everyday when you have solved such-and-such problem, another one arises.

### Testing electric machines; control

Abbate:

So you would do more work with motors...you weren't teaching all of Electrical Engineering? You weren't teaching Communications, or things like that, or Computers, but Power Engineering and Motors?

Poloujadoff:

Audio File
MP3 Audio
(294 - poloujadoff - clip 1.mp3)

Electrical lines, propagation, basic electronics, heat flow, strength of materials, but all of this is more or less connected to electric machines. I often say, control is a science without any utility, by itself. It's useful, because there are things to control. But an electric machine without a control, is not useful. An electric machine is made from mechanical parts, magnetic parts, conducting parts, insulating parts, and it vibrates. So, you have to know what is mechanical stress. You have losses. You have to know how it dissipates. You have to know some control, because if you cannot control the machine. Control is mainly electronic.

Abbate:

So you need to know that.

Poloujadoff:

I was very much interested, because you know railway people are always very conservative in technology, and for a very precise reason, that if your computer fails, or your typewriter, does it matter? If a train fails, it will kill people. So, that's the difference. Not very long ago, the French railways changed their ticketing system. There was a big failure. For two months, it was impossible to buy a railways ticket, unless you spent two hours or three hours. It was a disaster. But nobody was killed. In the locomotive, you cannot use the latest technology. If there is a failure, it's too serious. It takes five, six years, to design a locomotive. Then two, three years to test it. I've been involved in some of those works. The Southwest TGV is a very beautiful, technologically it's the most beautiful railways which exist. In about 1974, the French railways started the first studies of locomotives with synchronous motor. It was a success. And then they started to design the high speed train. And as far as I remember the first trains were ordered in 1984, ten years later. The first locomotives were working at that time. So it's a very, very long process. As another example, I was once looking at some drawings showing a part of the control for a large motor for railway purposes. Well it was very big space, full of small operational amplifiers.

Abbate:

Something like a meter wide...

Poloujadoff:

Well, it was almost two meters long and one meter wide. And plenty of small operational amplifiers on that. At that time I did not believe that operational amplifiers were still in use. But they were still in use in that, because the scheme had been tested and was rather reliable. That's electronics. So if you start from one given machine, and you try to study it, you end up in all directions.

### Integration of teaching and research; textbook publications

Abbate:

Tell me about your own research.

Poloujadoff:

Well, that's what I'm doing.

Abbate:

Well, yes. Did you look into problems that had a specific, you know like the railway asked you to look at something or the power company, or did you pursue things that were of interest to you? How did you decide what to work on?

Poloujadoff:

Well, I'm not a scientist. I am a professor. And that makes a lot of difference. For me, research is something that is tightly related to teaching. If I was a scientist first, I would choose a subject and keep it. I remember, one of my friends somewhere receiving somebody who would like to write their thesis. "Okay, I have this and that subject." "I'm not interested exactly in that." "I'm sorry, but..." That's it. So this is first scientist. Well, it's right to take things like this. This is not my general attitude. I remember, once somebody arrived in my office, explaining he came from Chile, and he wanted to do research on some subject. I said, "Okay, that's very interesting. So I have to find for you an advisor, and I believe you should look into Mr. So-and-so." And the other one said he had a very precise idea of what kind of thesis he wanted to write. He said, "Look, professor. I'm coming from Chile. In Chile, there is only one book on electrical power in Spanish, and this is your book. So I came here to work with you. So I want you to be me advisor." I tried to argue, but I couldn't. I ended up being his advisor. I wasn't probably a very brilliant advisor, but in fact I found some advice myself, so that the thesis was very good.

Abbate:

I noticed you had four textbooks that you talk about. That you wrote in Electrical Engineering. Is it unusual to write many textbooks for a professor?

Poloujadoff:

Oh, there is no rule. Sometimes you like to write textbooks, sometimes...well, it depends on how much time you have. It depends also...well right now I have a textbook which is finished. I don't have time to find a publisher. I started to look for a publisher three years ago. Well, I was in very advanced discussion with three of them, and then I got rheumatism, and I could not work too much for three or four months. So, I had other things to think about. I dropped the matter. I did not resume discussion. Sometimes, I believe I should write at least three letters to say, "Hello, I'm still there." Well, I'm not too much in the mood to do that.

Abbate:

Well, I ask because not all professors like to write textbooks. Did you think it was important? Were there not good textbooks already and you thought there should be?

Poloujadoff:

I've discussed two, three times with the American publishers. They ask you, "Do you believe your book will be better than the other ones?" I believe it's a real ugly question. And if they write to you asking, "Do you have a book to write?" So if they write to you probably they got your name somewhere. For example, they got my name from the same place you got it. They write to you a letter, and you see they mainly write the citation for such-and-such award, or whatever. You answer "Well, why not?" And they say, "Well, tell us how it will be better." You say, "Well, naturally I'm the best in the world." [laughter] It's not enough you see. It's ridiculous. I hate that kind of talk, "well, look how beautiful I am..." It's ridiculous.

Abbate:

Sometimes there's no textbook in some area that you want to teach and so you feel you have to write your own.

Poloujadoff:

It's not only that. Well, it may happen that sometimes there is no textbook. But sometimes there is no topic which becomes discernible immediately. You have two, three, four, five books. So, it's almost impossible to find a field where there is no textbook.

Abbate:

Except in History.

Poloujadoff:

Are you sure?

Abbate:

In some areas, the history of Engineering perhaps. If you want to write a history of Engineering.

Poloujadoff:

Well, I'm not so sure. I'm not too much interested in history. Well, I've been interested in history of squirrel cage induction motors and it took me some time to write what you've read on that very particular topic. But anyway, I took my material mostly from printed matter. What is not printed has been sent to me after I published something. But I was reading yesterday in the Encyclopedia Britannica, the history of Algebra. It seems that there is plenty of material now.

Abbate:

In some areas, yes.

Poloujadoff:

In some areas, well. In Engineering, if you watch in encyclopedias, old ones, I bought an old one...well, I don't know, it's your field anyway.

Abbate:

Let's get back to you.

Poloujadoff:

I know that there are professors on the history of Engineering in Paris. I don't know where. I heard from the students that there are courses in the History of Engineering.

Abbate:

This is the Université Curie we are talking about?

Poloujadoff:

No.

Abbate:

That's where you are teaching now, yes?

Poloujadoff:

No, in that university I don't believe you will find history, but probably at Conservatoire National des Arts et Métiers there is a chair of History of Engineering. You know it?

Abbate:

I don't know who the person is.

Poloujadoff:

But you heard of it?

Abbate:

I've heard of the school, yes.

Poloujadoff:

Of the school...

Abbate:

I didn't know there was a History of Engineering...Anyway, so you were talking about your research before we got started on History. So you said your research was tied to your teaching?

Poloujadoff:

Well, that's generally the way I choose my topics. What are the students interested in? It's a good opportunity to vary subjects, naturally. I have some Tunisian students who were interested in some problems about transformers. And transformers are very, very simple devices. The simplest devices in the field. And I never suspected there was some phenomenon so difficult to study.

Abbate:

Until you had these students?

Poloujadoff:

Yes. So, when they tried to start their research, and I was their advisor, I said, "Well, try to do this, try to do that." And they came back, and they said, "Well, it doesn't work." And then what?

Abbate:

So then would you end up going to the lab and looking at things to try to understand it?

Poloujadoff:

Yes.

### Corporate consultant work

Abbate:

Did you do any research for outside companies, for EDF or for the railways...

Poloujadoff:

Yes.

Abbate:

Would they come to you and say, "We have such and such a problem."?

Poloujadoff:

Sometimes it comes because you need money so you try to get a contract. Sometimes they need a consultant and they come to you. Sometimes they want somebody to write a thesis on a subject.

Abbate:

Really? So they would say, "We want someone to work in this area"

Poloujadoff:

Sure.

Abbate:

And then what?

Poloujadoff:

Well, very often in industry, people don't have time to think. They just rush to fulfill another order. So their problem is to have the staff, to have the equipment, to have a budget. So they do what you know how to do. But if there is a problem they don't have time to think, "What was the nature of the problem and will they have it again or not?" So in large companies sometimes they like to have a young engineer who is here not for the day today, but to think of the fundamental scientific problems of the company. Generally, they have special contract and so the young will get paid generally half by the company, half by the university. And the money of the university maybe will come from the company anyway because there are special arrangements. So the young man will have time to think about the how and whys without any time limit. He has just the time limit that he has to submit his thesis before such and such date. So it will be extremely interesting for a company, or utility. Or then the young person is working in the university, but on a contract with the industry, with more or less the view to join the company afterwards.

### Graduate students; graduate education as an international industry

Abbate:

So where do your students come from? Are there many who work with companies? You said you had some foreign students.

Poloujadoff:

I have many foreign students. Presently, most of them are foreign students.

Abbate:

Why is that?

Poloujadoff:

I don't know. I don't know, but that's the way it is presently.

Abbate:

Do you think the French have a reputation so people come and study there rather than where they are?

Poloujadoff:

Oh, yes, sure. In the Engineering schools, they have more French students than we do. Because they get their own former students to write theses. But they have a lot of foreign students too. Well, anyway I would say that in our countries...well, in the States, in Canada also, university is also an industry in itself. Well, how many foreign students do you have? Plenty I believe.

Abbate:

It's true.

Poloujadoff:

So, it's almost an export.

Abbate:

Do you mean that it's an industry in a sense that people come with money to get an education?

Poloujadoff:

More or less.

Abbate:

It's true. Do they stay in France after this?

Poloujadoff:

They try to. Well, to come back to Africa or to China, for the time being it's not enthusiastic. It's not very appealing.

Abbate:

So they don't come to solve problems back in the countries they come from?

Poloujadoff:



No.

### Engineering school in Tunisia; electrical program teaching

Abbate:

So other than going to Harvard and Canada, have you spent much time teaching outside of France or researching outside of France?

Poloujadoff:

I spent quite a lot of time in Tunisia, but not a long time. Many weeks. I believe I came there over thirty times. Thirty, thirty-five times. Something of that kind.

Abbate:

And why was that?

Poloujadoff:

The first time it was the starting of the Engineering school in Tunis. This was the first Engineering school in Tunisia. And it was created by. a very small team of Tunisian people and the help of the Soviet Union.

Abbate:

When was this?

Poloujadoff:

1973, around, I believe. The school started in 1970, and my former students who were living in Tunis asked for my visit around two years later. That's to say after the end of the general education period to establish the specialization programs. I believe the first class graduated in 1976. And in 1976, the head of the school was “given his bowler hat” as you would say for a general.

Poloujadoff:

Another Director was appointed, and all the consultants were discarded.

Abbate:

So, who first said that?

Poloujadoff:

This was in 1975. So I decided to take my wife for a vacation at Christmas 1976, in Tunisia. So I had very good friends in Genese. When I go to Genese, I don't go to a hotel. If my friends are not there, they say, "Well, the servants will take care of you." So, I came to Genese, and I decided just to go to the French Embassy to see some people I knew. The ambassador told me, "Oh well, you know, you should visit Professor Anabi. He's a very young professor, comes back from France. He wishes to do plenty of things. He will please you." So well, why not? So I go and I visit. There was something, in French we call it normal school. The word exists also in English, normal school, but you don't use it too much. Which is a school for professors. So I went and saw Anabi. He told me, "Oh well, I'm very happy to see you. I'm starting a Doctoral program. There is no Electrical Power, but if you are interested, I'll put Electrical Power in my program." Well, so I said yes and I worked with him quite a few years.

Abbate:

So you were teaching in Tunisia?

Poloujadoff:

Well, I was going, three, four weeks a year. I gave many courses within one week. Which wasn't too difficult in the beginning because, those courses were courses I knew very well. I have not too much to prepare and the audience was very small. The next year, the students of the first year had a project, and they came to me for advice. So I was absolutely overbooked. Well, we did that for a few years. So, I advised a thesis, on the place. Students would practically never come to France. They worked in Tunis. Sometimes they would come to France, but for a very short period.

### Invitation to assess Egyptian educational programs

Abbate:

So you started the Electrical program at this university in Tunisia, and you started one at that university in Canada, did you start any other programs?

Poloujadoff:

No, I don't believe so. Mainly I started a big lab in Grenoble. But, sometimes you start things without knowing. I remember once I was sent by...I don't know who, something like Unesco or the French government or somebody else maybe. I went to Egypt, to a university and I was asked to look at the program. Well, okay, I visited the Pyramids, I visited many things. At the end, I was very curious to know the utility of my visit. Except for the Pyramids, naturally, and for the nightclubs which were very gorgeous. Well, somebody asked me, "What do you think about our programs?" There was practically no important remark to make. Maybe only one, and I hesitated to tell. Well finally, I said, "Well, I find everything excellent. Maybe this and that." So we had a farewell banquet in December. In June, somebody came to Grenoble and said, "Well, I would like to write a thesis on that subject." Exactly what I had told the people, they were not good enough at. So this visit had been really useful, even in addition to the Pyramids. Another time, I had advised...somebody in France told me, "I wish to thank you because you sent us a customer. It was very nice of you." What? "Well, he had such and such problem," I don't remember. And the man said, "He had your card. And he told us you gave him our address. Very nice." And afterwards I remembered. I remembered and I was talking with some people and somebody asked me some information about such and such equipment. That's true, I gave him the address of some company, and they were very grateful. So you never know.

### Former students

Abbate:

I guess not. Do your old students keep in touch with you? Do you find out what they're doing?

Poloujadoff:

Depends. Most of the time, when they need you. But sometimes no. I have a former student who is in Iran. When he comes to Paris, he always comes to visit me. If he can bring a box of caviar, he does it. He's somebody who doesn't expect anything from me, just because he's grateful. I really made him a great favor. He was very embarrassed and it solved his problem, and well he's really indebted to me. But he does recognize it. Another time, I received a student who told me, "I wish to thank you for this and that." I was wondering, "What does he want?" He went on saying that I was this and that, even better. And I was wondering, "How much does he want?" This lasted for twenty minutes, half an hour. Suddenly, he said, "I'm sorry I did not want to stay so long. I've been so happy that I saw you. So, bye-bye, thank you again." I never saw him again. So, he didn't want anything. Really. But generally, most of them come back to you when they need something more. After that, you don't see them.

Abbate:

What would they need? Or what would they ask for?

Poloujadoff:

Well, it depends. Generally, I see again, former students who are professors in their own country and they want some help to get an international contract or to have a stay in my lab or that kind of thing. Otherwise, they just forget you.

### Lab at Grenoble; optimization theory, X-ray tubes

Abbate:

How big is your lab?

Poloujadoff:

Right now it's very small. I have four Doctoral students and an Assistant Professor, well that's it. But I have plenty of correspondents in other parts. I have correspondents in two French cities. One of my former students is a professor in Tunisia. This week, I had two Tunisians from Tunis. So, I spent almost half of my time working with people completely outside, not only my lab, but outside Paris.

Abbate:

And these are students of yours?

Poloujadoff:

Students or professors.

Abbate:

But you were working with them?

Poloujadoff:

Yes.

Abbate:

What are you working on now?

Poloujadoff:

Many things, well, electrical machinery naturally.

Abbate:

I mean, what kind of problems are...?

Poloujadoff:

It's difficult to explain. Well, let's make a list. Last week I was working with one who is writing about turbo generator exciters. Another one is working with transformers. Today, I was to work with somebody who was working on reluctance motors.

I'm very much interested also in optimization theory. Common sense is just one of the most powerful tools in optimization. Really, really. So naturally, you can multiply values of computers, but common sense is so important.

Abbate:

Can you teach that?

Poloujadoff:

No. That's the most difficult. What you can teach is "steepest descent". That's to say, if you design a machine with certain constraints, first you design one machine, then when you try to design another one for the same purpose, and you try to decrease the costs as rapidly as possible from one design to the other one. That's the idea of steepest descent. You try to bring down the costs. But there is a mathematical theory of steepest descent.

Abbate:

That you developed?

Poloujadoff:

No. It's something more or less obvious. Well, not really obvious for somebody who is not knowledgeable in mathematical analysis. But when you know some mathematical analysis, you can easily imagine that. So I am interested in optimization methods. What else? Well, some new machine for a purpose which is more or less confidential. Anyway, something to solve some old problem which cannot be solved until now. But it will be solved someday. Everyone knows...

Abbate:

Is that something a company is sponsoring?

Poloujadoff:

Yes, there is a company. Well, recently we took a patent on X-ray tubes, because in powerful X-ray tubes there is an electric motor and it's necessary to control it. So one of my former students came and said, "I need to do something." We took a student to try to apply one of my ideas. It was successful. What else? Well, some problems I've been thinking of for years, about some theoretical points. How can you prove this really?

Abbate:

You mentioned the X-ray patent. Have you received many patents?

Poloujadoff:

I'm not very much interested in patents because patents are for companies. If you take a patent, well somebody will just take another one, and he will say that his patent is better than yours, that you haven't seen this or that. I don't believe in patents. The right is for those who have the best lawyers. That's it.

Abbate:

So are there any more comments you'd like to make looking back on your life, your career?

Poloujadoff:

No, not really.

### Changes in the engineering field

Abbate:

Have you seen big changes in your area of Engineering?

Poloujadoff:

Oh, yes. Naturally. It's difficult to describe the changes in that area, because people who are not familiar don't see anything. If you look, for example, at aeronautics. For thirty years, the changes have been absolutely fantastic. This is true in all techniques. You don't see it as obviously, but the difference between old power plants and new power plants is just as spectacular than between a DC-10 and a Boeing 747. I remember, when I was a student, I visited a splendid power plant which was probably the best in the world. It was 200 megawatts. Now, you have some which are 1400. It's absolutely fantastic difference. Well, when I joined Grenoble University, to come from Paris to Grenoble it took seven, eight hours. I remember leaving Grenoble at six to be at a meeting in Paris in the afternoon. Arriving at the beginning of the afternoon. Now it's three hours and forty minutes.

Abbate:

On the TGV?

Poloujadoff:

Yes. The electrical equipment of cars is incredible. To roll down the window in a car, you have an electric motor. It was unbelievable thirty years ago. You could not believe of a motor small enough to take place in the door. And cheap enough. Plenty, plenty of things. Appliances. You know one of the biggest research areas now is how to run a washing machine?

Abbate:

Really?

Poloujadoff:

Yes. Nobody knows what will be the motor system of a washing machine within a few years. You imagine the importance of the market. It's a problem of structure of the motor, and electronics to drive the motor, and probably the software for some micro-controller. So there are plenty of things to do. One would expect that the motor not only will move the drum, but also will sense the weight of the load, its unbalance and that the system will re-balance the load. That's a challenge.

Abbate:

I would think so. That's something you're working on?

Poloujadoff:

No, that's another challenge is micro-motor. Right now, some people succeeded to make small motors to enter the veins. And one of the machinations is to use the manufacturing methods of integrated electronics.

Abbate:

It sounds like the whole idea of what a motor is changing in that case.

Poloujadoff:

More or less. But it has kept changing continuously. That's the reason why I was telling you a textbook on most subjects of technology may be always out of date. It can be updated. On almost anything, you can write an updated book. There exists plenty of out of date textbooks. Textbooks always die. Necessarily, on the same techniques. I don't know if there is a market for a textbook on automobile engines. But a textbook on automobile engines written today won't be anything similar to the book written twenty years from now. But apparently the technique is always the same. You have a piston and a shaft, and that's it.

Abbate:

But all the details are different.

Poloujadoff:

And people try now to replace the valves on the automobile engines by electric motors. Because the valves are very, very old fashioned and it's very difficult to make them to open or close when you wish. That's the reason they put sixteen instead of eight. Because sometimes you use some of them, but it's not a good solution. What they should like to have are valves which open and close anytime it is wanted. The mechanical system is not adapted to that. This is the way to improve the efficiency of the motors. That's why they have spent actually a billion francs right now by an association of automobile manufacturers. Billions of francs on that tiny...

Abbate:

That tiny piece, yes. Well, you've given me a quite a long interview. So thank you very much again.