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Stanford Japan Center hosts sensor technology conference

STANFORD -- Scientists from the United States and Japan - who might normally consider each other rivals - gathered in Kyoto, Japan, in late May to begin forging relationships they hope will lead to solutions to some of the most pressing environmental problems on the planet.

A two-day forum, "Sensors, Information and the Global Ecosystem," jointly sponsored by Stanford's Center for Integrated Systems and Stanford's Japan Center, brought together engineers, computer scientists, physicists, chemists and economists to discuss works in progress and to explore the possibility of collaborative efforts.

The international group of academic and industrial leaders and scientists discussed sensor technologies as diverse as monitoring contaminants in groundwater with tiny silicon sensors, remotely sensing the atmosphere with sound waves and radar, and rapidly identifying viruses and bacteria present in the human body using genetic sensors.

A main objective of the forum was to build a bridge between research conducted at Stanford and in Japan, said Professor Ken-ichi Imai, an internationally known scholar on Japanese industrial organization and director of research at the Stanford Japan Center.

In the opening keynote addresses, Stanford President Emeritus Donald Kennedy, the Bing Professor of Environmental Studies, and Jiro Kondo, president of the Science Council of Japan, outlined some of the scientific challenges - unavoidably intertwined with political and ethical considerations - currently in need of attention from experts on sensors.

Tale of the tiger

Kondo told a Buddhist tale of a monk who went walking on a mountain road and encountered a tiger dying of starvation. The monk offered his own life to feed - and thus save - the tiger. The story is especially meaningful to Kondo who has been working in collaboration with Russian scientists to gather data on the habitat of the endangered Siberian tiger.

"I believe that in order to live together or coexist with the environment," said Kondo, "we have to compromise our own desires. Otherwise the hungry tiger will pass away."

Kennedy also emphasized the need for individuals and whole countries to compromise their desires in order to preserve the environment.

"All the nations, and particularly the industrial nations, are going to have to give up things that they are not used to having to give up," Kennedy said. "The United States cannot afford to continue its present per capita energy consumption and at the same time argue that developing nations should hold back their own development.

"We cannot argue against deforestation elsewhere, unless we are taking care of our own diverse habitats," Kennedy said. "We have been complaining noisily in the United States about the Brazilians, but the percentage rate of loss of Northwest rain forests in the United States is greater than the rate of loss of rain forest in Brazil. We cannot occupy moral high ground unless we are performing up to the standards that we try to set for others.

"Japan can't continue its present level of demand for tropical hardwoods," Kennedy added. "We can't develop an orderly and sustained approach to the world's environment without some unprecedented sacrifices on the part of the rich nations, and those sacrifices are going to be politically impossible unless the database is hard, unless the database is reliable."

The data that sensors can provide will, therefore, be crucial to environmental-protection and restoration agreements that must be reached by political leaders around the world, Kennedy said. "Of course, the most innovative and elegant sensing mechanisms in the world cannot produce an environmentally benign outcome," he said.

Although currently there is no clearly defined "sensor industry," Imai said, sensor production and research and development are carried out in many different industries.

"Sensor innovations have the potential to enable a qualitative change in the systems that employ this new technology," Imai said.

CIS involved

Recognizing the importance of establishing a research strength in sensor technology, Stanford's Center for Integrated Systems initiated a thrust research program in sensors two years ago, said Professor (and center director) Robert Dutton, with the funding of Gregory Kovacs' work in integrated sensor systems.

"The broad impact of this work touches not only medical and commercial electronics, but is crucial in contributing to monitoring and even controlling environmental pollution and waste," said Dutton, one of the forum's organizers.

Kovacs, assistant professor of electrical engineering, spoke at the Kyoto meeting about his lab's work toward developing biological and chemical sensors for environmental monitoring. Among the repertoire of sensors for directly contacting the environment that Kovacs is developing are a heavy metal ion sensor that can detect groundwater contaminants in the parts-per-billion range, DNA-based sensors that "will soon enable rapid, parallel analysis of genetic material," and cellular sensors that bring living cells directly in contact with electronic structures on silicon chips.

"In addition to the directly funded sensors project from CIS," Dutton said, "Stanford has a long history in remote sensing as well as underlying sciences, including the earth and biological sciences. We have realized that gathering information about the environment is a long-term problem and that it is so big we have to cross national boundaries in order to solve it."

Allen Peterson, professor emeritus of electrical engineering, described a system for remote sensing of the atmosphere - combining radar and acoustic techniques - that he and collaborators developed at Stanford in the early 1970s. Since then, the technology has been carried by students between the United States and Japan, and in the process researchers have improved upon the technique. This radio acoustic sounding system (RASS) is now being combined with wind profiler radar - used to gather wind data and monitor weather fronts and squall lines - to acquire temperature measurements to heights of several kilometers, Peterson said. This information should prove useful for collecting data on global warming.

Storage problems

Handling the many bytes of data generated by sensor systems such as Kovacs' and Peterson's has created challenges in information management. For example, a single frame of data collected from the government-funded LANDSAT satellite consumes 300 megabytes of storage space. Ira Machefsky, director of external relations at Digital Equipment Corp., described a project his company is working on in collaboration with the University of California that aims to develop a computer system that will allow fast, easy access to the massive volumes of data earth scientists are beginning to collect via remote sensing technology.

"The Sequoia 2000 project will provide a data and information system that will help researchers develop a better understanding of the Earth," Machefsky said. Eventually, he said, a group of 100-terabyte storage servers will connect global change researchers and provide them with the ability to participate in collaborative research between campuses, access information from federal agencies and manipulate data in ways currently unavailable because of the limitations of storage and database systems.

Japanese efforts in biosensor technology, genetic sensors, systems for world environmental sensing and non-invasive brain functioning techniques were also part of the first day's agenda. Professor Isao Karube of the University of Tokyo's Research Center for Advanced Science and Technology, described Japan's leadership in the field of micromachining biosensors of all kinds. A particular interest of the Japanese, he said, is to develop biosensors for monitoring the health of elderly citizens, since by the year 2018, 25 percent of the Japanese population is expected to be over the age of 65. Karube and collaborators are working to outfit a toilet with sensors that could check temperature, blood pressure, heart beat, and weight and relay that information to a central health-monitoring agency.

During the second day of the meeting, about 20 experts gathered for a workshop on the technical details of sensor-based technology covering a variety of topics including medicine, consumer electronics, environmental and energy problems, neural networks, and sensor fusion, which is a method for integrating information gathered from several different types of sensors.

At the meeting's end, several participants admitted that they had not expected to learn much from a meeting that brought together experts on such disparate topics, but said they were leaving with exciting new information. "I learned that electrical engineers and physicists approach problems in completely different ways," said Shinichi Ichikawa, a Stanford alumnus currently with Hitachi Corporation's GREEN (global resources environment and energy) Center.

"Hiro Yamasaki talked this morning about information fusion, and I think some of what we're dealing with right now is intellectual culture fusion," Dutton said. "I expect that we would all like to continue communication, and I think the human bridge that we now share will be very valuable in continuing this discussion.

"This dialogue with leading contributors in Japan represents a major step in raising the level of technical interactions between the world's two industrial 'superpowers,' " he added. "Such a discussion, if carried into concrete collaboration and action, may serve as a major stimulus and motivator for other countries also to move forward in this important new area."



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