A History of ISCIE International Symposium on Stochastic Systems
Theory and Its Applications 1968 - 20181
Tohru Katayama
Professor Emeritus Kyoto University, Kyoto 606-8501, Japan
November 14, 2019

Abstract
This article is an extended version of my lecture on a history of the Symposium on Stochastic Systems Theory
and Its Applications（SSS) delivered at the 50th Anniversary meeting on November 1, 2018 [1]. It is shown
why and how the Symposium was launched in Kyoto 1968, and activities of SSS for the past 50 years are briefly
reviewed chronologically from my personal point of view.

1

Introduction

In 1968, at the first Symposium on Stochastic Control Theory, I presented a paper on nonlinear filtering, when
I was a PhD student studying estimation and control in the Laboratory of Prof. Sawaragi, Department ofApplied Mathematics and Physics, Kyoto University. Ever since, this Symposium has become an important
meeting place in my career. In this note, first I briefly mention the scientific advancement and organizational
developments of automatic control in the post-war period. I will then refer to the founding of the Japan
Association of Automatic Control Engineers (JAACE) in Kyoto 1957, and to the research on statistical studies
of nonlinear control systems in the Laboratory in 1950s and early 60s; I believe that both of them were cruciallyrelated to the birth of SSS in 1968. Moreover, based on Symposium reports and old documents about the SSS,
I will provide an overview of the activities of SSS for the past 50 years.

2

Automatic Control 1945 - 1960

After World War II, automatic control techniques developed during the war were released to the public as new
textbooks for the analysis and design of control systems in the US and Europe. Thus automatic control has
greatly been advanced both in the theory and applications, and at the same time, we saw that many societies
and institutions were reorganized so as to include automatic control as a distinct new discipline, and that great
eﬀorts were directed to standardizing terminology to be used in automatic control area [2,3]. Also, the concept of
feedback has attracted a wider audience due to the publication of Cybernetics and subsequent autobiographicalbooks by N. Wiener, which also helped automatic control to spread worldwide [2]. Further, in 1950s, several
international conferences on automatic control were held as shown in Table 1 [4–7].
Table 1: International Conferences in 1950s and the First IFAC World Congress.
Year

Conference Name

Place

1951
1953
1956
1956
1960

Automatic Control
Frequency Response Symposium
Problems of Automation
Automatic Control
The First IFAC World Congress

Cranfield, UK
New York, US
Milano, IT
Heidelberg, DE
Moscow, SU

During the automatic control conference at Heidelberg 1956, in a meeting held at University of Heidelberg, it
was adopted by members from 18 countries to establish International Federation of Automatic Control (IFAC),
1 http://sci-sss.org/Arc.html (Homepage of SSS)

1

where Prof. Izawa (Tokyo Inst Tech) attended the meeting. In the next year, the IFAC constitution was voted
in the First General Assembly in Paris, where Prof. Ishigai (Osaka Univ) represented the Japan National
Organization. Thus IFAC was established in September 1957 to promote science and technology of automatic
control and international cooperation [3, 4]; IFAC related earlier activities in the US and Italy are found in [6]and [7], respectively; see also [8] for a history of control engineering in Japan.
Supported by a large number of researchers and engineers in Kansai area, the JAACE was founded in
Kyoto, June 1957; the inaugural meeting was held at the Central Electric Club, Osaka [10, 11]. Also, in
September 1957, just after the birth of IFAC, the National Committee of Automatic Control2 was organizedin the Science Council of Japan, by inviting members from 12 Societies and Institutions involved in automatic
control. Then, the first National Automatic Control Conference, Japan, jointly organized by Societies in the
National Committee of Automatic Control, was held at the Osaka Chamber of Commerce and Industry in
November 1958 [12]. Presented were four plenary papers and over 100 contributed papers in the area of control
theory, components, and industrial applications.
In 1960, the first IFAC World Congress was held in Moscow; a number of distinguished professors, including
N. Wiener, R. Bellman, etc. attended this Congress [6, 13, 14], which ushered in a new era of automatic control
science and technology. In fact, it announced the advent of modern control theory based on state-space technique
due to R. E. Kalman [15]. The number of papers accepted was 286; the number of participants was about 1200.
From Japan 18 papers were accepted; but only nine delegates, including Prof. Sawaragi, attended the Congress.
It was the year 1964 that overseas travel was deregulated in Japan, so it was not easy to visit the Soviet Union
in 1960.

3

From Statistical Analysis of Nonlinear Control Systems to Theoryof Stochastic Control Systems

In 1950s, one of the projects3 in the Laboratory of Prof. Sawaragi was statistical studies of nonlinear control
systems. At the Heidelberg meeting in 1956, Prof. Sawaragi presented a new statistical linearization method,a key technique in the project, to analyze nonlinear control systems subjected to both a sinusoidal signal anda random noise [9]. In 1962, results of the research project that involved many people in the Laboratory were
published as a book [16], which was well circulated abroad. We note that the statistical linearization techniques
were developed in Russia, the US and Japan, and are still used today in the analysis of complex nonlinear
dynamical systems subjected to sinusoidal and/or random inputs; see e.g. [17].
Table 2: NSF-JSPS Joint US-Japan Seminars.
Year

Topic of Joint Seminar

Place

1966
1968
1971

Applied Stochastics
Applied Stochastics
Stochastic Methods in Dynamical Systems

Tokyo
Washington, D.C.
Kyoto

After the publication of the research monograph, Prof. Sawaragi organized a series of the Joint US-Japan
Seminars on Applied Stochastics with researchers interested in stochastic methods in engineering, see Table 2.
The first Joint US-Japan Seminar was held in Tokyo 1966, where Prof. Sawaragi reviewed statistical studies on
nonlinear control systems in the Laboratory. Before the first Joint Seminar, in January 1966, Associate Prof.
Y. Sunahara in the Laboratory visited Brown University, and stayed at the Lefschetz Center for Dynamical
Systems, where he met many active researchers in the area of nonlinear filtering and stochastic controls. I guessthat he witnessed many new trends in stochastic controls during his stay in the US, and he probably decided
that he should move from classical statistical analyses of nonlinear control systems to the study of stochastic
systems using stochastic diﬀerential equations. He returned to Kyoto in August 1967; then in April 1968, he
was promoted to full Professor of Kyoto Institute of Technology, where he set up a new Laboratory of stochastic
control in the department of mechanical engineering.
The preprints of the second Joint US-Japan Seminar4 includes 20 papers, the authors of which are listed
2 This committee has been playing the role of the IFAC NMO, Japan.
3 Other projects were: Nonlinear vibration of mechanical systems, Rheology (dynamics of visco-plasto-elastic materials), Classicalrelay and sampled-data controls, and process controls.
4 The second Joint Seminar was held for September 19–24, 1968. Preprints of the first (1966) and third (1971) Joint Seminars
are unfortunately missing, so that details of two Joint Seminars are not known.

2

Table 3: Authors of Papers for the Second NSF-JSPS Joint US-Japan Seminar.

1
2
3
4
5
6
7
8
9
10

Authors from Japan

Authors from the US

H. Akaike (Inst Statist Math)
Y. Sawaragi, T. Katayama (Kyoto U)
T. Isobe, H. Kobatake, I. Sato (U Tokyo)
S. Fujii, S. Y. Sheu (U Tokyo)
Y. Yamanouchi (Ship Research Inst)I. Nakamura (Railway Technical Research Inst)
H. Shibata, M. Miyamoto (U Tokyo)
Y. Ishii (Inst of Space & Aeronautical Science)
I. Kaneshige (Isuzu Motors)
Y. Sunahara (Kyoto Inst Tech)

W. Gersch (Purdue U)
R. Sridhar (Caltech)
B. Friedland (General Precision Systems, Inc.)
F. Kozin, C. H. Kozin (Brooklyn Polytechnic)
J. L. Bogdanoﬀ, A. Shiﬀ (Purdue U)
R. H. Lyon (Bolt Beranek & Neuman, Inc.)
R. F. Drenick (Brooklyn Polytechnic)
P. H. White (Measurement Analysis Co., LA)
M. Shinozuka, Jann-Nan Yang (Columbia U)
A. H. Gray (U California., Santa Barbara)in Table 3 [18], where we see many names from Tokyo areas. Then the third Joint US-Japan Seminar washeld in 1971 at Rakuyu Kaikan, where I had a chance to present a paper on nonlinear filtering under uncertain
observations. The purpose of the series of Joint Seminars was to promote research activities on stochastic
systems by exchanging information and ideas among participants. It was also a good opportunity to see
whether stochastic estimation and control are promising as a research area of the Laboratory. But, I should
say that at least by 1970, Prof. Sawaragi decided to tackle diﬃcult global issues in systems sciences, including
environmental pollution controls, etc. Hence, studies on stochastic control systems were taken over by Prof.
Sunahara at Kyoto Institute of Technology and partly by myself at Kyoto University.

4

Birth of Symposium

At the 1968 planning committee meeting of JAACE, Prof. Sawaragi proposed to launch a new symposium
called “Stochastic Control Theory”. The proposal was approved in the Board Meeting of JAACE, and Prof.
Sunahara was appointed to the chair of organizing committee of the new symposium [19]. The first Symposiumon Stochastic Control Theory 第 1 回統計学的制御理論シンポジウム was held at Rakuyu Kaikan in November
1968 by the enormous eﬀorts of Prof. Sunahara; he decided the format of Symposium, including Abstracts,
Proceedings, Presentation in English, etc. Thus he made a great contribution to the SSS; in fact, Prof. Sunahara
was the chair of organizing committee of SSS until 1994.
The above is a short story why and how the SSS started in Kyoto 1968; I should say that the leadership ofProf. Sawaragi and the hard work of Prof. Sunahara brought the success of SSS today. The following are mypersonal view on the activities of SSS for the past 50 years; the main sources of information are SSS related
articles and reports appeared in the Journal of our Society. Also, the documents prepared for the special session
on Stochastic Systems for the 50th Anniversary Meeting of ISCIE in 2006 [20] are very helpful, since it includes
all the titles of papers from the first (1968) Symposium until the 37th (2005) Symposium.

5

Name Change of SSS
Table 4: Name Change of SSS
Year

Name of Symposium

1968

第 1 回統計学的制御理論シンポジウム (The First Symp. on Stochastic Control Theory)

1975

第 7 回確率システムシンポジウム (The 7th Symp. on Stochastic Systems Theory
and Its Applications)1985

The 17th JAACE Symp. on Stochastic Systems Theory and Its Applications

1988

The 20th ISCIE Symp. on Stochastic Systems Theory and Its Applications

1995

The 27th ISCIE International Symp. on Stochastic Systems Theory and Its Applications

3

The change of name of the Symposium is depicted in Table 4. As mentioned above, the first Symposium
was held in 1968 at Rakuyu Kaikan, Kyoto University. The oﬃcial name of SSS was in Japanese until 1984.
The Journal “Control Engineering” featured the first SSS in the special issue of August 1969 [19]; I noticed
from the English contents of the issue that 統計学的制御理論 was translated as “Stochastic Control Theory”
as in Table 4. Although 統計学的 ≈ “statistical”, I understood for the first time that the word “stochastic” instead of “statistical” has been used from the start of the Symposium.
In 1975, the Symposium’s name was changed from 統計学的制御理論 to 確率システム; see Table 4. This namechange gave a feeling of uneasiness to some of the participants as we can see in the article documented in [20].
In fact, by the change from “statistical” to “stochastic”, the scope of the Symposium may be narrowed, so that
papers on statistical signal/image processing and applications of simple statistical analyses may be rejected,
resulting in the reduced number of papers and participants. I will be back to “statistical” and “stochastic”
issue later in Section 7 to show according to the scope of the IFAC Technical Committee on Stochastic Systems
that “stochastic” includes both “statistical” and “probabilistic”.
Then, in 1985, the English name became the oﬃcial name of the Symposium, so that it was decided that
only the papers written in English were acceptable. Also, oral presentation in English was recommended; but
this was not mandatory at that time. In 1988, the name of our Society was changed to the Institute of Systems,
Control and Information Engineers (ISCIE) [21]. Accordingly, JAACE in the name of Symposium was changed
to ISCIE. Moreover, International is added to the Symposium title in 1995. So, we are using the present nameof SSS for nearly 25 years; this name is now widely accepted in control community of Japan.

6

A Half Century of SSS

Activities of SSS for the past 50 years are reviewed. For convenience, dividing the 50 years into five decades, wesummarize the activities of Symposiums in each decade as tables, including the place, the number of papers5 ,and special lecture(s) with some remarks. We also explain memorial events held every ten years.

6.1

The first decade 1968-1978
Table 5: Symposiums 1968-1978
Year

Place

PapersSpecial Lecture(s)Remarks

1

1968

Kyoto, Rakuyu Kaikan

28/85

Y. Sunahara

2-day meeting

2

1970

ditto

30/83

3

1971

ditto

23/90

4

1972

ditto

26/91

5

1973

ditto

33/123

6

1974

ditto

24/88

7

1975

ditto

41/105

8

1976

ditto

29/79

9

1977

ditto

38/93

10

1978

Holiday Inn, Kyoto

50/96

3-day meeting

T. Nishimura
Name change

F. Kozin, K. Ito

Table 5 displays the year, the symposium site, and the number of papers/the registrants for the first ten
symposiums. The first nine symposiums were held at the same place, Rakuyu Kaikan. The first Symposium wasa two-day meeting with a single track. The second Symposium was held in 1970 as a three-day meeting with asingle track, and this latter style of meeting was continued until the 17th Symposium in 1985. We note that thesecond Symposium was held in 1970 with an interval of one year. This was due to the fact that the Symposium
organizer could not decided whether the Symposium should be held every year or every other year. Since thefirst two Symposiums were successfully received good number of papers and participants, it was decided that
the SSS should be held every year from the third Symposium.
At the first Symposium in 1968, Prof. Sunahara gave a special lecture on the second Joint US-Japan Seminar(see Table 3)6 , and at the sixth meeting in 1974, Prof. Nishimura gave a special lecture on linear/nonlinear
5 Both the number of papers and of registrants are shown.
6 The preprints of the first SSS does not include his paper, so that details of the lecture are not known.

4Kalman filters in the space science in the US based on his long experiences at the JPL. And, in 1978, the 10th
Anniversary Symposium was held at Holiday Inn, Kyoto; we had two invited lectures by Profs. Kozin and Itoon stochastic diﬀerential equations. It was quite interesting that the title of the talk of Prof. Ito was on theStratonovich integral.

6.2

The second decade 1979-1988
Table 6: Symposiums 1979-1988
Year

Place

PapersSpecial Lecture(s)Remarks
3-day meeting

11

1979

Tokyo, Fujitsu

48/95

T. Kitagawa
Y. Takahashi

12

1980

Kanazawa Inst Tech

30/83

S. Ueno13

1981

Kyoto Inst Tech

51/82

F. Kozin

14

1982

Kobe, KICC

34/79

15

1983

Kyoto Seminar House

44/76

16

1984

Hamamatsu, Murakushi-so

40/64

17

1985

Kansai Seminar House

53/75

International

18

1986

Tokyo, Mita Press

68/ -2 parallel tracks

19

1987

Kyushu Univ

38/71

20

1988

Osaka, Mita Press

56/86

J. Balas, F. Kozin

Table 6 shows the list of the Symposiums for the next ten years. The 11th Symposium was held in Tokyo for
the first time at the Institute for Social Information Science, Fujitsu Laboratory. We had two interesting special
lectures: “Statistical Control Processes in Quality Control” by Prof. T. Kitagawa (Fujitsu & Kyushu Univ)
and “Progress in Control Engineering – Interaction between Technology and Science” by Prof. Y. Takahashi(Toyohashi Univ of Tech & Berkeley). Ever since, it was decided that the Symposium should change the place
every year. In fact, we visited Kanazawa, Kyoto Institute of Tech, Kobe, Kyoto Seminar House, Hamamatsu,
Kansai Seminar House, Tokyo, Kyushu Univ, and Osaka as shown in Table 6.
In 1985, the Symposium became an international symposium by the eﬀort of the Chair, Prof. Sunahara.
This fact was certainly stimulated by the fact that we had the 8th IFAC Kyoto World Congress in 1981, thepresident of which was Prof. Sawaragi. In 1986, abandoning the long tradition of the single track meeting
due to the increase of number of submissions from overseas, the SSS became a three-day meeting with twoparallel tracks. Also, the poster session started this year; though continued until the 24th SSS in 1992, it was
discontinued since we had many no-show papers.
In 1988, we celebrated the 20th Anniversary of SSS at the Mita Press, Osaka; Profs. Balas and Kozin gave
special lectures on the nonlinear filtering and the statistical linearization, respectively.

6.3

The third decade 1989-1998

Table 7 shows the Symposiums held during 1989 – 1998. We also visited many places: Tokyo, Hiroshima, Osaka,
Kyoto, Osaka, Beppu, Kyoto, Tokyo, and came back to Kyoto in 1998.
I should mention that the 1993 Proceedings was published for the first time in the history of SSS. Table 7
includes three numbers in the column of Papers from the 25th Symposium of 1993; the first one denotes thenumber of papers in the Proceedings published after reviews and revisions, the second is the number of papers
presented at the Symposium, and the third is the number of participants. Today, we can look at and download
all the papers in the Proceedings from 1993 through the webpage of J-STAGE without charge.
A part of the Preface in the first Proceedings is quoted below, since I believe that the idea of Prof. Sunahara
is well expressed in it.
– Organization of the Symposium was motivated by the fact that there has been a great upsurge in research
activities in the field of Stochastic Control Theory – both among mathematicians and engineers．Since the first
Symposium, a quarter century has passed and the SSS in 1993 constitutes the 25th International Symposium.
For this occasion, publication of the proceedings of the Symposium has been inaugurated. It goes without
saying that the principal objective of the SSS is to bring together groups of the researchers and provide a forum
for presentations and discussions on the recent advances in stochastic control theory and application in various
5fields of estimation, control, identification, stochastic system analysis, etc. with particular emphasis on the
coupling of theory and application techniques [22].
Table 7: Symposiums 1989-1998
Year

Place

PapersSpecial Lecture(s)Remarks

21

1989

Tokyo, Fujitsu System Lab

49/65

T. Kitagawa

3-day meeting

22

1990

Hiroshima, Information Plaza

40/71

J. Weizenbaum

23

1991

Osaka, Mita Press

48/64

24

1992

Kyoto, Ritsumeikan Univ
Suekawa Memorial Hall

56/67

25

1993

Osaka, Mita Press

41/47/73

26

1994

Osaka, Mita Press

32/36/61

27

1995

Beppu, B-Con Plaza

42/ - / -

28

1996

Kyoto, Ritsumeikan Univ

27/ - / -

29

1997

Tokyo, Waseda Univ

50/ - / -G. Kitagawa

30

1998

Kyoto, Kyodai Kaikan

44/48/78

K. Nishiguchi
G. Giannakis, P. Stoica

G. P. Rao

Proceedings

In July 1997, the 11th IFAC Symposium on System Identification SYSID’97 was held at Kitakyshu, where
Prof. Sunahara was supposed to be Chair of the Symposium; but he unfortunately passed away August 1994,
after returning from the IFAC SYSID’94, Denmark, July 1994. The future organization and steering of SSS
were discussed; and it was decided that senior Profs. S. Sagara (Kyushu Univ), K. Akizuki (Waseda Univ) and
T. Nakamizo (National Defense Academy) should take over the role of late Prof. Sunahara, and that Chair will
not be fixed, and a local organizer will be nominated for each future SSS. This is now the standard procedureof the organization of SSS. In 1994, the SSS organized by Prof. Sagara was held at the Mita Press, Osaka; see
Table A in Appendix for the past chairs of SSS. In 1998, the 30th Anniversary was held at Kyodai Kaikan,
Kyoto Univ. We set up Sunahara Memorial Lecture in order to commemorate the long time contribution ofProf. Sunahara to the Symposium organization. Thus, in addition to a special lecture by Dr. K. Nishiguchi on
the large deviation, we had two Memorial Lectures by Prof. P. Stoica on Spectral estimation and by Prof. G.
Giannakis on Cyclostationary signal analysis. Sunahara Memorial Lectures have continued until 2009.

6.4

The fourth decade 1999-2008
Table 8: Symposiums 1999-2008
PapersSpecial Lecture(s)Remarks

31

Year
1999

Tokyo, Keio Univ

Place

58/ - / -A. Nehorai

2-day meeting

32

2000

Tottori, Hotel Monarque50/59/84

S. Bittanti

33

2001

Ashikaga Inst Tech48/ - / -M. Bremer

34

2002

Fukuoka, Papillon-24

44/ - / -A. H. Sayed

35

2003

Ube, Yamaguchi Univ

52/56/ -T. Katayama

36

2004

Tokyo Denki Univ

61/ - / -C. F. Martin, G. Picci

37

2005

Otemon Gakuin Univ

45/47/98

H. Takayasu, G. Peskir

38

2006

Suwa, Hananoi Hotel

33/40/67

S. Kondo

39

2007

Saga Univ

40/51/80

O. Bay, Y. Ikegami

40

2008

Kyodai Kaikan

62/66/119

J. Oommen, B. K. Ghosh

Table 8 displays the Symposiums during 1999 to 2008. We visited Yokohama, Tottori, Ashikaga, Fukuoka,
Ube, Hatoyama, Osaka, Suwa, Saga, and came back to Kyoto in 2008. Since the 31st Symposium at Keio Univ
in 1999, the SSS was shortened to a two-day meeting. Also, a session of mathematical finance was organizedby specialists for the first time in 1999. Moreover, I should mention that during this decade, a number ofdistinguished guests from overseas were invited to Sunahara Memorial Lecture, including Profs. A. Nehorai(US), S. Bittanti (IT), A. Sayed (US), C. F. Martin (US), G. Picci (IT), G. Peskir (UK), Bay (US).
6

In 2006, besides the 38th Symposium in Suwa, the SSS organized a special session for the 50th Anniversaryof the ISCIE at SCI’06 [20]. The 40th Anniversary of SSS was held at Kyodai Kaikan in 2008, where we had
two Sunahara Memorial Lectures: Prof. Oommen, Learning Automata, and Prof. Ghosh, Visual model offreshwater turtles. Some of the senior members were invited to the banquet of the Anniversary; see Photo 1.

Photo 1: A group photo with some senior professors at the banquet of the 40th SSS 2008, Kyodai Kaikan, Kyoto
Univ, Kyoto. The first row from the left: Profs. A. Ichikawa (Kyoto U), N. Baba (Osaka Kyoiku U), M. Nakamura(Saga U), K. Uosaki (Osaka U), T. Katayama (Kyoto U), B. J. Oommen (Carleton U), M. Ohta (Hiroshima U), T. Ono(Osaka Prefecture U), T. Nishimura (JAXA) & his wife, B. K. Ghosh (Texas Tech U), C. F. Martin (Texas Tech U), H.
Kano (Tokyo Denki U)

6.5

The fifth decade 2009-2018
Table 9: Symposiums 2009-2018
Year

Place

PapersSpecial Lecture(s)Remark41

2009

Kobe, Konan Univ

52/61/111

A. Isaksson

2-day meeting

42

2010

Okayama Univ of Sci

44/48/82

H. Kunita

43

2011

Lake Biwa, Ritsumeikan Univ

61/69/101

H. T. Banks, F. Kappel

44

2012

Kokushikan Univ

51/61/84

S. Sugimoto/T. Katayama

45

2013

Univ Ryukyus

63/78/128

M. Yamazato

46

2014

Kyoto Inst Tech

39/53/ -A. Ohsumi

47

2015

Waikiki Marriott, Hawaii

53/86/ -B. K. Ghosh

48

2016

Fukuoka Inst Tech

34/52/72

M. Nagahara

49

2017

Hiroshima Inst Tech

32/47/70

T. Moriya

50

2018

Hotel Granvia Kyoto

40/72/107

T. Katayama

Table 9 shows the Symposiums in the last ten years. The last Sunahara Memorial Lecture was given by
Prof. A. Isaksson on a model predictive control at the 41st SSS in 2009. From this year, English presentation
became mandatory. So it was quite recent that we had the present style of Symposium. Then, in 2010, we
went to Okayama. In 2011, we had the Symposium on the boat Bianca at Lake Biwa in the first day and at
Ritsumeikan Univ, Kusatsu in the second day. We then went to Tokyo for the 2012 Symposium. In 2013, the
SSS went to Okinawa, where we had 128 participants; see Photo 2 below.

7

Photo 2: A picture of participants at the banquet of the 45th SSS 2013 at University of the Ryukyus, Okinawa

In 2014, we had SSS at Kyoto Inst Tech, and in 2015, the SSS was held overseas in Hawaii for the first timein the history of SSS. We had the Symposium in Fukuoka in 2016, and visited Hiroshima in 2017. Further,
we had the 50th Anniversary Symposium at the Hotel Granvia, Kyoto, November 1–2, 2018, where Profs. S.
Sagara, K. Akizuki, T. Nakamizo, A. Ohsumi, M. Sugisaka and K. Wada joined the banquet in the evening ofNovember 1, 2018. It was really pleasant to see each other on a great occasion like this. Also, I should mention
that the 51st SSS was held at the Aizu Univ, Fukushima, in November 2019.

7

On “Statistical” and “Stochastic”

Prior to concluding, I should make a brief comment on “statistical” and “stochastic” mentioned in Section 5.
I was Chair of IFAC Technical Committee (TC) 1.4: Stochastic Systems for three years from 1999 to 2002.
The IFAC has 40 TCs, most of which organize their own Symposium or Workshop every three years. But
TC 1.4 does not have its own Symposium, but co-sponsors Symposiums and Workshops related to stochastic
systems. Probably, they decided that it was diﬃcult to have Symposiums every 3 years under the keyword:
Stochastic Systems. The scope of TC1.4 says: – TC 1.4 focuses on statistical and probabilistic methods
in modelling, analysis, estimation, identification, decision, control, etc. Stochastic systems arise in various
disciplines within engineering and science, such as control, communications and networks, signal processing,biology and finance [23].
“Stochastic” is usually translated as 確率的な in English-Japanese dictionaries7 ; but the Scope of TC1.4
clearly indicates that “stochastic” includes both “statistical” and “probabilistic”. In modern probability theory,
we solve forward problems by giving a mathematical model together with a probability space; this is a deductive
reasoning that derives useful theorems on the model. In statistics, however, we consider inverse problems, i.e.
we test or estimate a model (hypothesis) based on given data. Hence, the latter include inductive reasoning
based on data, but it also fully utilize knowledge from the probability theory, i.e. a deductive method . The
conclusion of the reasoning in statistics is therefore not necessary true, but there is a possibility that it expands
the knowledge about the system under study; see Table 10 below. In general, methods of sciences should include
both deductive and inductive reasoning as in the hypothetico-deductive method [24]. Scientists often combine
deductive and inductive reasoning quite easily in their daily research activities. Both probabilistic and statisticalmethods are needed in our SSS for analyzing, modeling, and designing stochastic systems. Hence, I believe that
we should understand that the scope of our SSS includes both statistical and probabilistic methods; we should
not narrow the scope of our Symposium.
7 “Stochastic” is often used in the context of dynamic system such as stochastic processes, ∼ diﬀerential equations, etc.

8Table 10: Probability Theory vs. Statistics.
Probability theory

8

Statistics

Forward problems

Inverse problems

Model ⊕ Probability space → Theorems

Data ⊕ Model ⊕ Probability space→ Model estimation or model validation

Deductive reasoning

Both deductive and inductive reasoning are included

Premise is true → Conclusion is always true

Premise is true → Conclusion is not necessarily true

Information does not increase

Information increases

Conclusions

The birth of the Symposium on Stochastic Systems Theory and its Applications in 1968 and the subsequent
activities for the past 50 years have briefly been reviewed. To consider why the Symposium started in 1968
Kyoto, I explained the status of automatic control in 1950s and the related research activities of the Laboratoryof Prof. Sawaragi at Kyoto University. Also, to describe the past events related to SSS, I basically used theactivity reports on Symposiums published in the Journal of the Society. Since the reports used are so many
that they are not listed as references. But, I found that reports about the past Symposiums are not complete,i.e. some of them are missing, so that I could not recover all the Symposiums of the past 50 years. Thus someof the data in the columns of Papers in Tables 6 to 9 are missing. I hope that Tables should be updated infuture.
In the coming age, our social system will heavily be influenced by new technologies, including big data
sciences and AI; so is our SSS. In fact, we are in a rapidly changing world quite diﬀerent from that of 50 years
ago when our SSS started in 1968. It is important to adapt ourselves to a new trend quickly; but it is more
important to have a solid foundation to get an insight into the underlying key issues of the new trends, for which
I believe the statistical analyses and probabilistic reasoning play key roles. I sincerely hope that the future of
the SSS in the next 50 years is successful in developing new ideas and methods, especially by the intelligenceand continuing eﬀorts of younger people, i.e. coming generations.

Acknowledgments
I should very much appreciate Prof. Sugimoto (Emeritus Ritsumeikan Univ), Chair of Organizing Committee of
SSS, who gave me a chance to write this short history of SSS and supported me in finding earlier documents, andProf. Ohtagaki (Okayama Science Univ), Chair of Local Organizing Committee, for his support in searching old
documents from the Library of Prof. Sunahara. I am also grateful to Prof. K. Wada (Emeritus Kyushu Univ),
Prof. H. Sakai (Emeritus Kyoto Univ) and Prof. K. Takaba (Ritsumeikan Univ), who read the manuscripts
and gave me very useful comments. Finally, I should extend my sincere thanks to the staﬀ of the secretariat of
ISCIE for assistance in finding SSS related old articles appeared in the Journals.

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pp. 5–7, 1959.
[6] http://a2c2.org/history/history – Homepage of American Automatic Control Council[7] S. Bittanti: A Century of Control Science, In Control Science Evolution – 50th Anniversary of Control
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9[8] T. Kitamori, N. Suda, E. Shimemura, M. Masubuchi, H. Kimura and Y. Yoshitani: Control Engineeringin Japan: Past and Present, IEEE Control Systems Magazine, November 1984, pp. 4–10.
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Sinusoidal and Gaussian Inputs, Proc. Int. Conf. on Automatic Control, Heidelberg, pp. 271–274, 1956.
[10] T. Nishihara: Inaugural Address - Start of the Japan Association of Automatic Control Engineers, Control
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Appendix
Table A: Chairs of Organizing Committee of SSS 1968 – 2018.
1

1968 (1st) – 1993 (25th)

Y. Sunahara (Kyoto Inst Tech)2

1994 (26th)

S. Sagara (Kyushu Univ)

3

1995 (27th) – 1996 (28th)

K. Akizuki (Waseda Univ)

4

1997 (29th) – 2000 (32nd)

T. Nakamizo (Ashikaga Inst Tech)

5

2001 (33rd) – 2011 (43rd)

T. Katayama (Kyoto Univ)

62012 (44th) – 2018 (50th)

S. Sugimoto (Ritsumeikan Univ)10