The National Science Foundation's (NSF) Tokyo Office periodically receives and disseminates reports on research developments in Japan that are related to the Foundation's mission. NSF-sponsored researchers currently working in Japan prepare many of these reports. These reports present information for use by NSF program managers and policy makers; they are not statements of NSF policy. .
The following report was prepared by Dr. S. C. Liu, Program Director, Division of Civil and Mechanical Systems, NSF. Dr. Liu visited Japan from June 25, 1998 and July 16, 1998 as a Visiting Research Fellow (short-term) under the sponsorship of the Japan Society for the Promotion of Science (JSPS). Professor Hiroyuki Kameda of Kyoto University, Kyoto, Japan served as host scientist for Dr. Liu. Dr. Liu may be reached via email at: sliu@nsf.gov
INTRODUCTION
From June 25 through July 16, I visited several institutions and laboratories under the sponsorship of the Japan Society of Promotion of Science Invitation Fellowship. The purpose of this visit was to interact with Japanese scholars working in the areas of earthquake and wind engineering, structural control, and smart materials and structures at various Japanese universities and national research institutions and laboratories, and to explore the possibility of collaborative research activities in the near future. The primary host for the visit was Professor Hiroyuki Kameda of Kyoto University. He was extremely helpful in planning and organizing this visit.
During this visit, I was stationed primarily at four locations in Japan: (1) Kyoto, (2) Osaka, (3) Tokyo, and (4) Tsukuba City. The institutions I visited and activities at these locations are described in the following.
VISITS IN KYOTO AREA: JUNE 25 - JULY 1, 1998
Fukui was my first stop in Japan and I attended the International Symposium on Urban Earthquake Disaster (June 25-26) that commemorated the fifty-year anniversary of the famous Fukui earthquake of June 28, 1948. This earthquake almost totally destroyed Fukui City. The city has since undergone remarkable reconstruction and recovery and is now a modern, prosperous, mid-size city. The American soldiers who were stationed in Japan during the time of the earthquake made great contributions to the search and rescue, and post event reconstruction.
Kyoto was my second stop in Japan. In Kyoto I participated in the following activities and meetings: (a) Joint US-Japan Workshop/Seminar on Cooperative Research in Structural Control for Civil Infrastructure Systems, and (b) 2nd World Conference on Structural Control.
The joint workshop/seminar was sponsored by NSF on the US side and JSPS on the Japan side. The objectives of the workshop were to: (1) identify the current status of research, (2) identify research information, data, facilities that can be shared in cooperative research, (3) identify critical research issues in this area, (4) identify specific research projects for cooperative research, and (5) formulate an action plan to promote and conduct joint research.
I made a keynote presentation at the opening session of the workshop and participated in the working group activities and discussions during the workshop, and at the final meeting on July 1, 1998.
The World Conference on Structural Control, held every four years, is the primary meeting event for structural control researchers and enables the exchange of research ideas and their dissemination to a wider audience. The 1st World Conference on this topic was held in Los Angeles in 1994. My participation in this conference was extremely useful in the context of the objectives of this JSPS sponsored fellowship visit. This meeting offered an excellent opportunity to meet, in a single location, with almost everyone working in this area in Japan and the US.
VISIT TO OSAKA, JULY 2-5, 1998
In Osaka, I visited the Department of Architectural Engineering of Osaka University. My visit was hosted by Prof. Yutaka Inoue. I met with Prof. Inoue, Prof. Eizaburo Tachibana, Prof. Kensuke Baba, and Dr. Yoichi Mukai. I had an excellent opportunity to discuss the research work of Prof. Tachibana, Prof. Inuoe, Prof. Baba, and Dr. Mukai in the area of building dynamics, soil structure interaction, and control of structural response due to earthquake and wind forces.
VISITS IN TOKYO AREA, JULY 5-12, 1998
In the Tokyo area I visited several institutions and sites, and met with numerous people in the teaching, research and corporate sectors. Among the teaching and research institutions, I visited the Civil Engineering Department at Tokyo Institute of Technology (TIT), and the Civil Engineering Department and the Institute of Industrial Science at the University of Tokyo.
Professor Kazuhiko Kawashima was the local host for my visit to the TIT on July 7, 1998. I had an opportunity to visit the laboratories at TIT, and meet with Prof. Saburoh Midorikawa, Prof. Kazuhiko Kasai, Prof. Chitoshi Miki, and Prof. Katsuki Takiguchi. Professor Kawashima described to us TIT's graduate program and the current research activities in the Department of Civil Engineering at the Tokyo campus of TIT. Prof. Midorikawa and Prof. Kasai described the program at the Interdisciplinary Graduate School of Science and Engineering at the Nagatsuta campus of TIT. In particular an outline of the research activities at the Structural Engineering Research Center, Department of Built Environment, and the Department of Environmental Science and Technology on the Nagatsuta campus were described. Prof. Midorikawa made an excellent presentation about the recent state of the art disaster prevention at Yokohoma City's High-Concentration Seismograph Network, installed by the Office of Disaster Management of Yokohoma City. This highly useful and effective network displays the intensity maps in only a few minutes after the occurrence of an earthquake event; it sends out beeper signals in different wards of the city. It consists of 150 strong motion accelerographs, and bore hole sensors with three data processing centers displaying the intensities on the Internet. It can be used for real-time damage assessment in an actual earthquake event. Profs. Kasai, Miki and Takiguchi also discussed their research activities at the Nagatsuta campus of TIT.
On July 8, I met with Ms. Shinohara from the NSF Tokyo office, and visited the Department of Civil Engineering at the University of Tokyo. My visit was hosted by Prof. Y. Fujino. I also had an opportunity to meet and discuss the US-Japan cooperative research program with Prof. S. Otani of the Department of Architectural Engineering, University of Tokyo, who is the Chairman of the Technical Coordination Committee on the Japan side. In the afternoon, I, along with a few other visiting American researchers, participated in the US-Japan Structural Control Symposium by Young Researchers, organized by the Department of Civil Engineering, University of Tokyo. The presentations were made by Japanese graduate students and the US students visiting Japan as part of the US-Japan Summer Programs. There were 8 presentations by the US graduate students, and 11 presentations by Japanese students. The student presentations were based on their graduate research work in the area of structural control done at their respective universities and organizations. The presentations were on quite interesting research topics in the area of structural control and were very good. This meeting, I believe, was extremely successful in promoting the scientific interaction and exchange of ideas at the graduate student level. It also provided an excellent opportunity for the US graduate students to develop very important personal and professional contacts with their Japanese counterparts in the early stages of their research career.
On July 8, I also had an opportunity to meet with two senior executives: Dr. Hiroshi Yamahara, Senior Managing Director, and Dr. Toshiaki (Toshi) Fujimori, Deputy Director, of the Shimizu Corporation. Shimuzu Corporation is a leading construction company in Japan, with excellent research and development activities in the area of structural control. This meeting was very informative.
On July 9, I visited the Institute of Industrial Science, University of Tokyo, with Prof. Takafumi Fujita. I visited his micro-vibration control lab. Dr. Fujita is a leading researcher in the area of seismic isolation using lead rubber bearings, application of hybrid mass dampers, control of buildings and nuclear facilities, semi-active control of base isolated structures, and control of micro vibrations in extra sensitive industrial facilities. I had an excellent opportunity to visit and discuss his experimental set up in labs on control of micro-vibrations and base isolation.
On July 10, I, together with the visiting American students and other researchers, visited the Trigon active tuned mass damper system installed at the Shinjuku Park Towers by Kajima Corporation. The group toured the site of these installations, and discussed the installation with Mr. Satoshi Ohrui and Mr. Mitsuo Sakamoto of the Kajima Corporation. Shinjuku Park Towers complex consists of three multi-story buildings joined together. The lower part of the building primarily consists of offices and the upper part is a luxury hotel. The building system is installed with three active tuned mass dampers at the 39th story level, primarily to control annoying vibrations in the hotel floors caused by strong winds. The period of the active tuned mass damper can be mechanically adjusted by simply changing the rolling radius of the mass by using spacer blocks. The device is quite compact. For active control, damper mass is driven by a motor to enhance the passive response control effect provided by the tuned mass damper. It has been observed to be quite effective in controlling the building response during strong winds. It has also been activated during several earthquake events that have occurred since it was installed. As the control system is not designed to control strong earthquake induced building vibrations, large damper oscillations that can occur during a strong earthquake are limited by stoppers. IHI Corporation with Kajima Corporation designed the control system. The Kajima Corporation is also the designer and builder of the Shinjuku Park Towers.
In the evening, I met with Dr. Shin Okamoto, Director General of the Central Research Institute for Construction Technology. Dr. Okamoto is known for his contribution to the US-Japan cooperative research program on composite and hybrid constructions and was a former Director General of the Building Research Institute in Tsukuba.
VISITS IN THE TSUKUBA SCIENCE CITY AREA, JULY 12-16, 1998
I was in the Tsukuba City area for three days. My visit in Tsukuba was hosted by Dr. Takashi Kaminosono, Head of Construction Techniques Division, Production Department of the Building Research Institute (BRI).
Monday, July 13, 1998
On the first day of my visit, I visited the research facilities of the Building Research Institute where I met with Dr. Yutaka Yamazaki, Director General, Dr. Hiroharu Habu, Deputy Director General, Dr. Hiroyuki Yamanouchi, Director, Codes and Evaluation Research, and Dr. Kazumasa Watanabe, Director, Dept. of Production Engineering, who very kindly discussed with me the broad research activities at BRI . This was followed by visits to various laboratories at BRI headquarters. In particular I visited the Structural Laboratory, Large-scale Structure Testing Laboratory, Structural Composite Test Laboratory, Fire and Test Laboratory, Full-scale Fire Test laboratory, Building Element Laboratory, Creep Test Laboratory, and the Laboratory for Building Foundation and Soils. During these visits, I also had the opportunity to discuss research activities at BRI with: Dr. Mitsumasa Midorikawa, Head, Building Engineering Division; Dr. Satoshi Kose, Director, Research Administration and Management; Dr. Naohito Kawai, Head, Evaluation Systems, Codes and Evaluation Research Center; Dr. Izuru Okawa, Head, Building Engineering Division; Dr. Hitomitsu Kikitsu, Aerodynamic Division; Dr. Nobuo Hurukawa, Associate Director, International Research Cooperation; Dr. Hiroshi Kuramoto, Large Scale Structure Testing; Dr. Taike Saito, Structural Division; and Mr. Namihiko Inoue, Structural Engineering in their respective areas of research interests.
On the same day I also met with Dr. Tsuneo Katayama, Director General, National Research Institute for Earth Science and Disaster Prevention, Science and Technology Agency. In this institute we visited with Dr. Chikahiro Minowa and Dr. Kuramoto, the Large-Scale Earthquake Simulator Laboratory of the STA/National Research Institute for Earth Science and Disaster Prevention Center. Currently, the shaking table at this facility is the largest one in Japan. A larger, multi-dimensional shaking table facility to be located just outside Kobe, is currently under planning by STA. The new facility is expected to be built and operational in a few years.
Tuesday, July 14, 1998
On the second day of my stay in Tsukuba, I visited the following research centers and laboratories. The hosts for these visits are indicated in the parentheses. I primarily visited the researchers involved with smart materials and structures.
Visited their quake-free laboratory and clean laboratory. The quake free lab is a base isolated structure, designed to remove very small quakes and vibrations from moving vehicles so that precise measurements can be made with the electron microscope. The clean laboratory primarily filters out the dust and invisible particles in the environment.
At NRIM I visited their Intelligent Materials Research Group with Dr. Norio Shinya. This group is involved in the development of multi-function intelligent materials. The idea is to assemble particles in a proper manner to achieve multi-and systematized functions in the new material to have certain properties. The special methods that are being considered for desirable particle assembling are the micro-probe and electron beam methods.
Dr. T. Yoshioka hosted our visit to the roller bearing testing facility used for predicting failure. The technique is based on acoustic emission measurements. We also visited the smart materials integration for electron mechanical systems with Dr. Jun Akedo and Dr. Masaaki Ichiki, followed by a visit to the smart structures for active noise reduction with Mr. Yoshihiro Kikushima and Dr. Salem Sivrioglu.
Dr. K. Kemmochi, discussed with me his conceptual development of new materials that are high performance, high function, and environmentally safe and cost effective. We discussed his research on environmentally conscious smart composites and multi-function sandwich panels that are lightweight, can absorb impact, can insulate noise, can provide electromagnetic shielding, and are highly corrosion resistant. I also visited their smart and composite material and met with Dr. Jun Takahashi who is involved in research in smart composites
Wednesday, July 15, 1998
On my third day in Tsukuba, I visited the Public Works Research Institute (PWRI) and its various laboratories.
First I was given a general overview of PWRI, and its research activities, by Dr. Yasutake Inoue, Director General, and Dr. Michio Okahara, Director, Structures and Bridge Department. This was followed by visits to the following Divisions:
These meetings were followed by visits to the Boundary Layer Wind Tunnel Laboratory where a scaled model of a suspension bridge was being prepared for testing; Earthquake Engineering Laboratory; wheel running machine for fatigue testing of bridge girders; geotechnical centrifuge, and the large-scale three-dimensional shaking table.
CONCLUDING REMARKS
On the whole, this JSPS sponsored trip to various Japanese institutions was a very exciting and rewarding experience. It was an immense pleasure for me to meet with many outstanding Japanese educators, researchers, engineers, and research administrators. The research that I observed being conducted by Japanese engineers was of the highest quality and of immediate practical value. I am specially obliged to each and everyone I met on this visit for sharing their time, scientific data, and information freely. I am looking forward to enhancing the already fruitful and productive relationship that we share with our many Japanese colleagues.
ACKNOWLEDGEMENTS
I wish to express my gratitude to the Japan Society of Promotion of Science for making it possible for me to undertake this exciting and worthwhile visit. The financial support provided by the JSPS is gratefully acknowledged. I am also grateful to Prof. H. Kameda of Kyoto University for hosting this trip, and for providing much needed help, support, and overall guidance in the planning and execution of the visit.
I would also like to thank everyone I met on this trip at Kyoto University, Osaka University, Tokyo Institute of Technology, University of Tokyo, Shimuzu Corporation, Kajima Corporation, Building Research Institute, Public Works Research Institute, National Institute for Research in Inorganic Materials, National Research Institute for Metals, Mechanical Engineering Laboratory, National Institute of Materials and Chemical Research, and the Research Institute of Technology of Konoike Construction Company. I am grateful for their generous hospitality, for the generous exchange of ideas and scientific information, and for the precious time they spent with me.
Finally I would also like to express my most sincere thanks to my colleague Dr. Larry Weber of the Japan and Korea Programs at NSF who inspired me to take part in the JSPS Research Fellowship program under which this visit was sponsored, and the office of NSF/Tokyo and its entire staff, especially Ms. K. Shinohara, who painstakingly took care of me during my entire, complex itinerary. Without her constant support and timely arrangements, this trip would not have been the success it was. I am ever so grateful for her exceptional and superior help.