Oral-History:Hans Marko

About Hans Marko

Hans Marko is a telecommunications engineer and professor in Germany. He studied at the Technische Hochschule Stuttgart until 1951 when he earned his diploma in communication studies. His doctoral thesis was on distortion and frequency modulation. After working for a company affiliated with ITT, he went to work at SEL where he worked on data transmission over telephone lines, focusing particularly on error-detecting codes. In 1962, he was offered professorships at both the University of Aachen and the University of Munich; he accepted the position at Munich and taught communications techniques there until he retired. He is currently chairman of the technical faculty at the Academia Scienciarum et Artsum Europaeum and is active in a variety of German and international associations. He is best known for his work on multidimensional systems theory and on bidirectional communication theory.

The interview begins with Marco's education. Marco then describes his industrial experiences at an ITT affiliate and at SEL, including his development of error-detecting codes and of PCM systems. He describes his career at Munich, emphasizing his own interest in systems theory and information theory and describing the various systems- and information-related projects he has worked on. He describes the three research groups with which he has been affiliated during his academic career — one on communication transmission systems; one on picture processing and transmission, and the third on cybernetics. After briefly describing Munich's communications curriculum and his various visiting professorships, he discusses what he thinks are his most important contributions to his field: first, his development of a multidimensional systems theory, and second, his development of bidirectional communication theory. He lists the various professional organizations to which he belongs, and describes his association with the Academia Scienciarum et Artsum Europaeum. He outlines what he believes will be the next important areas of development in communications engineering and names Kumpfmuller and Reichhardt as important names in cybernetics and Hagenauer and Dorsch as important names in the developing German research on information systems. The conclusion ends with Marco's comments on IEEE journals and conferences.

About the Interview

HANS MARKO: An Interview Conducted by William Aspray, IEEE History Center, June 30, 1993

Interview # 168 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.

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

Hans Marko, an oral history conducted in 1993 by William Aspray, IEEE History Center, Piscataway, NJ, USA.

Interview

Interview: Hans Marko

Interviewer: William Aspray

Place: Munich, Germany

Date: June 30, 1993

Childhood and Education

Marko:

I was born in Kronstadt/Transilvania. This country now belongs to Rumania. There is a German group called "Siebenburger Sachsen" They've nothing to do with Saxonia, but at that time "Saxonia" meant "Germany".

Aspray:

I see.

Marko:

And we came from Luxembourg and Mosel eight hundred years ago to protect Europe against eastern enemies, like Tartars and Turks. In my hometown, Kronstadt, I made the Abitur. And then during the war I was in the German Air Force. There was an agreement between Rumania and Germany that the German people could go into the German army. As I had been trained in glider flying and also had a license, I went to the Deutsche Luftwaffe, the German Air Force. But I didn't fly in the war. I got the training as a fighter pilot until the end of the war. Then I went to the Technische Hochschule (Technical College) in Stuttgart, and studied there until 1951. Then I got my diploma in communication techniques. My teacher was Professor Feldtkeller, a famous professor in Germany. He wrote many books and had many students who later were promoted to become professors and so forth. A whole school of academics.

Aspray:

I just met Karl Ulrich Stein over at Siemens, and he was also a student of his.

Marko:

Many trained at that school. Then I was an assistant for Professor Feldtkeller and in 1952 I entered in the company SEL — Standard Electric Lorenz, A.G. At that time the company belonged to ITT. Now it belongs to Alcatel. So I made many contacts with the London people and also to the American subsidiaries of ITT.

Aspray:

Let me go back for just a second and ask you: in your education, what was in the curriculum in telecommunications at the time?

Marko:

At Stuttgart Tech do you mean?

Aspray:

Yes. What was taught to you? What was the emphasis in the course work you did?

Marko:

At first, as I had been a pilot, you see, I first wanted to study air mechanics. But at this time it was not possible in Germany. So I then made my first study in mechanical engineering. The first four semesters were identical for both electrical and mechanical engineering. Afterwards, I observed that electrical was much more interesting. In respect to the fundamentals, the whole building of electrical science and especially communication techniques. And I studied this.

Aspray:

What were the topics that were covered most carefully in this course of study?

Marko:

Professor Feldtkeller had some specialties. One was iron and ferromagnetism, the second was acoustics, and the third was modulation systems. There I did my thesis for my diploma on frequency modulation. I developed a theory to understand the ratio-detector. This was a frequency-modulation receiver, which many companies produced, but no one understood well. And so I made a theory to understand the rectification process used in this circuit, the "transvector." During my study I was invited by many companies to report on this theory, companies involved with the production of FM receivers and so on. This was before my graduation. My doctoral thesis was devoted to distortions, with frequency modulation, and then I went to SEL. That was Dr. Steinbuch, who later would become the first professor of data processing in Germany. He also wrote some famous books.

Standard Electric Lorenz, A.G.

Aspray:

What were your responsibilities at SEL?

Marko:

First, it was the first time I had looked at a repeater for coaxial cable systems. So I had to study the theory of feedback amplifier design according to the famous book by Bode. But then I became responsible for the general development lab of SEL, the lab which was both involved in research and with advanced systems. Together with my colleagues I investigated the possibilities for a data transmission system over existing telephone lines. The Bell people had the idea to use error-correcting codes, but they never succeeded, because with mechanical selectors the noise was so bad that no error-correcting code could work. Therefore, we made measurements and then we had the idea to use block retransmission with these error-detecting codes. We developed the system and it was presented at a CCITT conference in Geneva This was the first data transmission system for switched telephone lines with error correction retransmission and a very low final error rate.

Aspray:

Was it!

Marko:

Yes. The next thing was we developed was the first PCM system in Europe. This was delivered to the German Army for experimental use. During that time, I had very good contacts with Bell People working on the hierarchy of PCM systems (T1 to T4). Then we studied the synchronization methods for PCM systems. My first doctoral student in Munich, Dr. Häbeule, proposed concentrated synchronization in contrast to the distributed method, which was used by Bell. Due to his work concentrated synchronization was then accepted worldwide.

Technical University, Munich

Marko:

In 1962, I got two offers to be a professor in communication technics, one from Aachen and one from Munich. I accepted the call from the Technical University at Munich and I became the successor of Professor Piloty. He was a pioneer in network theory and especially on synthesis of networks. Also, he initiated together with Professor Sauer, a mathematician, the development of one of the first electrical computers. It was called PERM. Within the corresponding working group has been Dr. Robert Piloty, later Professor in Darmstadt and Dr. Bauer, later Professor in Munich. But this development has been done before my time here in Munich.

Aspray:

Why don't you tell me about your career here at the University?

Marko:

Well, in November 1962, I accepted the call to Munich and have been Professor here for a little more than 30 years. Also, Professor Piloty and the previous Professor have been active for about 30 years. It is interesting.

Systems Theory & Information Theory

Aspray:

I see. What did you focus your research on here at the university?

Marko:

I was not so much engaged in the special circuits or special electronics; my focus was on systems. So my first lectures here were on systems theory, modulation methods, and information theory. I wrote a book Springer-Verlag called Methods of System Theory. This refers to time-functions, and the methods used are Fourier-Transforms, Laplace Transforms, Hilbert Transforms and some others. Later on, I made a generalization leading to a multi-dimensional systems theory. so it was possible to treat pictures in two dimensions or moving pictures in three dimensions with the same methods. This was published in a later edition of my book with Springer-Verlag called Systemtheorie (Methods and Applications for One and Multidimensional Systems). With information theory, I proposed a generalization of Shannon's information theory, in the sense of a communication theory. With Shannon's theory, the information source is independent. But in a dialogue like ours, the source is not independent, but in fact it is dependent on what it receives. So I made this generalization to a bidirectional communication theory. It appeared in the Proceedings of the IEEE, but it is not very known in the USA. Professor Massay now at Zurich, is one of the experts on information theory in the USA who understood it very well, but otherwise it is not common in the U.S. Its application at this time was more with biology. At the Max Planck Institute for Psychiatry here in Munich, they investigated the group behavior of monkeys, and we applied the communications theory in this case. With respect to the information flows we could distinguish a dominant from a subordinate animal.

Aspray:

Interesting.

Research Groups

Marko:

Here in Munich, my institute had three research groups. One was communication transmission. In this first group we developed PCM systems, coaxial cables, and later on for glass-fibers, and we tried to optimize such systems. We had a good cooperation with the Siemens company, and also with the research lab of the German Post Office. For instance, one of our research works was the synchronization of two lasers, which was necessary for the heterodyne or homodyne system. I think it was the first time in the world that we synchronized two lasers in order to realize a homodyne system. But this is over, so now a new area has begun with my successor Professor Hagenauer who is active in mobile communication. So this is a natural development. That was the first group; the second group was on picture processing, and pattern transmission. This was also close to the human performance, so we tried to find an understanding of the human visual system, also using this multidimensional systems theory, treating the visual neural networks as a system. Furthermore, we developed a system for the recognition of handwritten symbols. This was later continued by Dr. Fukushima in Japan, who also visited us at the time. To investigate picture processing, one of my assistants, Mr. Platzer, developed a coherent optic array with a distinguished performance using also holographic methods. So this was one area under the heading of picture processing. The third one was under the heading of cybernetics. Here we investigated the human visual system under the leadership of Professor Hauske. Those are the groups, my research areas.

Aspray:

I see. Did you have many students?

Marko:

Beginners in our electrical engineering program were in the order of seven hundred. Now it's decayed to about four hundred. About fifty per cent of them reach usually the final degree, the diploma. Our faculty nowadays is named Electrical Engineering and Information Techniques, so there's a double name now. Most of the students are connected with information techniques or automation technics, and only about ten per cent are studying power engineering. Does that answer that question?

Contributions to Field

Aspray:

Yes. I see that you've been a visiting professor at many different places around the world.

Marko:

That is true. I've been at Delft, in the Netherlands, for a time, and I've also been in the Soviet Union. Professor Siforov invited me. He was the president of the Academy of Sciences in the USSR. I accepted an invitation from IBM, and had a very nice time in the U.S. at different places such as at USC in Los Angeles. I spent another year at the University of Tokyo and some other universities in Japan.

Aspray:

What would you say are the most important of your own contributions, personal contributions over time, technical ones?

Marko:

Well, after my first work on error correction for data transmission with telephone lines, I think the systems theory and the development of systems theory to a multidimensional theory including neural network understanding is one major idea. The second contribution is information theory and its generalization which I will called bidirectional communication theory. As I mentioned, it has been published but it is not very known in the USA.

Information Technical Society

Aspray:

All right. I understand that you've been active in professional activities and helping with standards and things of that sort.

Marko:

Well, we have a society, the ITG, which means the "information technical society" in Germany. I've been active in that, of course. There is also a professional group on systems and information theory where I have been the chairman, and I'm still working with that group. Then there is the DRAGM, the Deutsche Arbeitsgemeinschaft sür MustererKennung, a German group for investigating pattern recognition. I have been one of the founders and the first chairman of this group. The newest activity you'll see is now the Academia Scientiarum et Artium Europaea. It was founded in Salzburg and I am the Dean of the technical class. It's traditional that academies have no technical classes; they have philosophical classes, they have science classes, but they have no technical classes. That was the first time that a new academy in Europe, which was not only devoted to the sciences but also to the arts, had a technical class. I have promoted it very much.

Retirement and Hobbies

Aspray:

What other things would you like to tell me about your career that we haven't talked about already?

Marko:

Well, we are only speaking of course of my professional things. I am now retired and so, you see, I am now more or less able to spend more time on my hobbies, which are sailing — I have a sailing boat — and flying. My first hobby was glider flying. In the Alps, it is possible to stay for hours with a glider, because in the mountains you may get good thermals.

Superminiaturization, Multimedia & Stereo TV

Aspray:

Maybe we could turn to a different topic. I'd like to get your guidance on what are some of the big issues to cover in some of the areas you've worked in. So, for example, in cybernetics, or information theory, or pattern recognition, what are the topics, internationally speaking, that just have to be in any survey book?

Marko:

Of course that's a very, very big area. Of course, effectiveness of all communications techniques depends upon the development of electronics or optronics. There are no limits on the time. In super miniaturization, we have very, very much room to progress. Multimedia communications — one thing for instance is the stereo television. Just now, one of my doctoral students did his thesis on how much information you may transmit supplementary in order to go from mono to stereo. It is very little information. Using the disparity of the left and right eye. Another development which may go on is the high-definition television. The networks will become more effective in order to transmit such broadband signals. Glass fiber of course is certainly one direction of development. Then mobile communication, which for the future is very important, anybody can at any time be connected to any one. Then of course we have to mention the progress of computers and computer science as a succession of our cybernetic activity. We founded the Institute of Sensomotorik in Munich, together with some medical people. It's in Grosshaden, which is a very big clinic at the University of Munich. This is a cooperation of the Technical University and the University of Munich. This Institute of Sensomotorik may investigate the whole Sensomotoric circuit — from the perception of information to the possessing of information to action. Man or living beings are on one side and robotics on the other. We investigate this parallel to automatics, robotics, and medical problems. This is the old idea of cybernetics as proposed by Wiener.

Cybernetic and Information Theoreticians

Aspray:

So if you were to identify the two or three people in Germany who have made the most significant contributions in the cybernetics area, who would you identify?

Marko:

Well, I think Professor Küpfmüller is one. His ideas on systems theory were original. With respect to cybernetics: it is a very good thing to treat the systems, regardless of whether they are electrical or biological systems, the same way. The other is Professor Reichardt of Tubingen, who died about a year ago, not much before. He was the editor of the journal Biological Cybernetics, and his successor is now Professor Hauske.

Aspray:

What about in information theory? What names would you mention from the past?

Marko:

Information theory. There was Professor Hagenauer, my successor, for coding theory for instance. Also Professor Dorsch. Otherwise, in the theory field, there has not been very much activity in Germany. Mostly practical things are done here, like coding, transmission of information, and so on, not so much in the theory of the field. Well, and I should mention also Professor Neuburger, who wrote a book on the multidirectional communication theory of a group. And up to now, the theory up to three sources is completely understood. With more, it becomes difficult, but with two or three sources influencing each other, this is already known.

Aspray:

Where was it, do you think, that most of the work on theory was done in this area? What country?

Marko:

What country?

Aspray:

You said that Germany was not so strong in the theory work; it was more on the practical sides in this area. Where was the theoretical work done?

Marko:

The theoretical work — well, it was Shannon and Wiener in the USA, and then the IEEE Professional Group on Information Theory was very much theoretically directed. They are trying to prove theorems on coding theory, limits on transmission and so on, and not so much to build systems. But of course communication engineers are very much interested in applications of this theory.

Language Gap between US & Germany

Aspray:

Are you other things that you want to tell me about? You've answered the kinds of questions that I had in mind.

Marko:

Well, let me ask: what is the purpose of this? There may be some gap between what is produced here in Germany and what is known outside.

Aspray:

German engineers can read English but the English engineers can't read German.

Marko:

Sometimes, of course, German people publish in English. But that's not always the case. Usually the first works of the Diploma or the Doctorate are in German and are not completely known to the outside.

IEEE

Aspray:

Why did you join IEEE? What value do you find in IEEE?

Marko:

Well, it's a very useful organization, of course, and the biggest engineering society in the world

Aspray:

Right. Do you go to their conferences; do you read their journals?

Marko:

Yes, of course, the journals we have in our library. Also our young people very often visit international conferences. They normally speak quite good English. Better than I.

Aspray:

Okay. Thank you very much.