Interview with Prof. Gyu-Hyeong Cho

Since the establishment of KAIST in 1972, KAIST has made a great contribution to the development of science and engineering in Korea. In particular, KAIST Electronics Engineering has greatly developed the Korean electronics industry, which was poor in fundamentals, and now has excellent competitiveness. I met Professor Gyu-hyeong Cho who is a witness of the history and the master of circuit design that started with KAIST’s electronic department. What is the current status and future of electronics, the prospects of analog design, and what advice does he give to his followers?


Q. First of all, thank you for your time during your busy schedule. You have been in KAIST for a very long time, exactly how many years did you serve?

A) Since November 1983, I have been working as a professor at KAIST Electrical and Electronic Engineering.


Q. You have been in office for a very long time. I can also refer to the professor as the living history of KAIST School of EE. What was the department at that time compared to today?

A) I was the third graduate of KAIST. At that time, KAIST had 135 students, 19 of whom were electronics students. It had a few department and there were only four professors. At that time, KAIST was very popular because of military service and tuition fee exemption, and financial support. Professors were treated specially, and their pride was very high. In 1975, I received my master’s degree and went to doctorate. When I first selected the doctoral students in KAIST, 4 students were selected in the EE department. Two of these four are Prof. Jong Min Kyung and Prof. Byung Kook Kim and are now professors in our department. Compared with the present, the research environment at that time was so bad that there was one computer in the whole circle.


Q. What do you think about the present position of KAIST School of EE and the way forward?

A) In fact, KAIST School of EE has a high position to say that there are few in Korea. Our school is dominant even if we look at only the Samsung Human Technology papers. KAIST is very well known abroad and it belongs to the top class. There is a society called ISSCC called Olympic in the field of semiconductor circuit design. In the field of circuit design, since it is a thesis that the chip is made and operated, it represents the technological power of the country. Even in the first half of the 2000s, almost no paper was published in the ISSCC in Korea. It was all American, European, and Japanese. However, in recent decades, KAIST has become the largest institution in the world to publish articles on ISSCC. Each year, more than 10 of the 110 papers ISSCC issued by universities came from KAIST. As a result, interesting things happened, and it has been stopped giving statistical presentations by country and school every year for 60 years. KAIST continues to be the number one player. In other words, KAIST can be said to be the best in the world in the field of semiconductor circuit design. Therefore, when a foreign company chooses a KAIST graduate, it takes it on equal terms with a US top college graduate. In the future, we must go to the open competition such as ISSCC and make the first prize. Therefore, they will know KAIST. This is what we have to do, and we must do our research well.

Q. Please tell us briefly about your research and your current focus.

A) I changed my major once. Prior to 2000, I was in the power electronics sector. When I first entered KAIST, there was no semiconductor company in Korea. I wanted to design a circuit, but I did not have a place to go to work. I could not make a chip and I could not get my thesis anywhere. The environment was not good. So, we started power electronics field. The power electronics field was almost the first in Korea. From the 1980s to the 2000s, I studied in the field, many of students graduated majoring in the field. There are a few companies that have done well enough to be listed on the KOSDAQ, and they are in fields that require very large power such as electric trains, high-speed electric tanks, and fusion power plants. Perhaps the company established by a student from our laboratory is in charge of the power supply of the largest fusion power plant in the world. As you see, it was a success in power electronics, but by the end of the 90s, Samsung Electronics began making memory. As the memory grew, the media praised memory, but it did not know anything but the memory. There was nothing on the system semiconductor and there was only memory. Memory is also an important area in electronics, but system semiconductors account for four times as much as the memory market in the entire market. The analog field belonging to this system semiconductor is considerably big, and Korea was very weak in this field. Therefore, we thought that we need to develop other fields besides the memory field in order for Korea’s electronics to grow. Since I was in the analog field, I thought I would train analogue talents and develop the field to help society. In addition, the semiconductor market was much bigger than the power electronics field that I had been focusing on, and the power electronics field was already well established in the background. As a result, we have changed the direction of analog circuit design from the traditional power electronics field. Since then, we have started to publish papers in the ISSCC. Since that time, we have consistently published theses, and by 2013, we have become within 16 of the 10 groups that have published the most thesis articles in the 60th ISSCC history and the 10 groups that have published the most articles in the last 10 years. In KAIST Electronics Department, there was I (Prof. Kyu Hyeong Cho) and Prof. Hoejoon Yoo. Our lab graduates are very proud of our lab.

Q) I know that you were interested in starting a business as well as research.

A) I thought the venture was very important before the venture boom took place. Prof. Terman, a founder of KAIST, told me, “Your goal now is to train industrial manpower, but after 20 years you will have to revise your goals.” Nevertheless, after 2000, and 30 years after its establishment, the reality was almost like the first time. As a result, we decided that the road to buy was a venture. Therefore, I emphasized and promoted the importance of venture. “See KAIST” (an event that demonstrates and introduces technologies that are calling and researching / developing various industries) was held for the first time in the School of EE and conducted for about 10 years. Then I started my own business and I did my best. I was not able to achieve satisfactory results, but it was a good experience that I could inspire students and circuit designers to start a business and devote themselves to other areas of research.


Q. Is there any academic advice you can give to graduate students or undergraduates in the field of circuits?

A) I would like to say to undergraduates that if I follow the school curriculum well, that is enough. Since the undergraduate is a basic learning stage, you have to work hard to advance into a field that is attracted and attracted to your aptitude. When you study, you will find out what field is suitable for you. The most important thing is to do what you really like.


Q. What kind of students do you think are good students?

A) Good research requires creativity. Some students have creativity, and some have a little creativity but very hard working. If you have a sense, you will feel confident when you go to a company or start a business. Because each person has different abilities, it is all right to supplement the lack of effort.


Q. The book on the special course for electronic circuit you have written is very famous among the students in a way that it is in a different approach from the existing textbooks, and I am wondering if other domestic and foreign students are learning from it.

A) The special course for electronic circuits is only for KAIST students. Since I am going to retire in the summer of 2018, I will be opening classes until spring of next year. After that, I do not know yet. The book on the spcial course for Electronic Circuits is published only in Korean version and not published in English. It will spread out slowly, but I want to spread slowly. Nevertheless, I’ve been told that because I have been teaching for a long time, the book is spreading through my graduates. Recently I got a call from a professor in Vietnam. The professor has been typing my book, translating it into a translator and studying, and asked if I could send the original. Of course, I refused, but I will release it overseas when I get English version later.

Q. What does a professor as profession means to you?

A) To me, the meaning of the professor is to communicate and research with the students. If you like to communicate with students and study together, I think that professor is the best job. I am also satisfied with it and enjoy it. However, when I became a professor, I received my Ph.D. degree without industrial experience, and after two years as POST-DOCTOR, I became a Professor at KAIST. Some people graduated from college, gained industrial experience, and returned to professorship. They have a corporate background, so they have connections with companies and teach more based on field experience. If you want to be a professor, I recommend that you come to the professor after experiencing the company. By actually experiencing it, you will be better able to guide your students and know how the world actually works.


Q. I am wondering how you have long maintained your passion for research.

A) I have no choice but to keep my enthusiasm and enthusiasm for students. If students have a desire to learn, they will naturally have enthusiasm to follow along. KAIST in the world is No. 1 is also motivated to continue research.


Q. Please talk about the future prospects of the analog circuit you have been studying.

A) I say that the analog has gone through a digital shift, but IC circuit chip design still requires an analogue engineer. Because the size of the device is small, it works like an analog. Therefore, we need to continue research in analog field. In addition, there are not many engineers because this is a very complex and talented field. Therefore, the analog engineers will be scarcer and more valuable. In fact, analog engineers pay higher salaries in the US. I think this situation will continue in the future.


Q. Finally, please tell me about the prospect of electronics.

A) Nobody knows the outlook. However, when I was admitted in the early 1970s, electronics was the most popular in all areas, and its popularity continues to this day. There has never been a department that has been so popular for 50 years, and it is miraculous and tremendous to maintain it. I do not know what will happen in the future, but I do not think there is anything else that can replace the information revolution. Recently, software has been getting attention and development, but we need hardware to support it. You cannot have software without hardware. Therefore, I think that electronics as a hardware will be maintained.


I would like to express my gratitude to Professor Gyu Hyeong Cho for his interview.


Reporter, Se-yeop Kim,

Reporter, Tae-Jung Yoon,

Reporter, Jung-Hyo Kim,