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The paper puts forward a new Chinese concept of ‘Wu Liu’ (material flow) which is different from the concepts of logistics and physical distribution popular in the West and Japan in four aspects: characteristics, contents, properties and applications. The paper points out that the research on material flow science and technology in China has lagged far behind, especially in the application aspect of material flows which is not in line with the position that material flow holds as the third biggest backbone industry group of the national economy. The paper also discusses issues in researching material flow in economic development, social development, as well as natural sciences. At the end, a framework of material flow science and technology is proposed which includes four components: disciplines supporting material flow science and technology, engineering and technological disciplines supporting material flow science and technology, theoretical disciplines supporting material flow science and technology, and other disciplines supporting material flow science and technology. About forty disciplines are related to material flow science and technology which need to be either built or enhanced. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Underground pipeline infrastructures, such as water supply and industrial water pipes, were rapidly constructed in Japan during the 1970–1980s economic boom and have been ageing quickly. In general, corrosion of buried metal water pipes depends on the physicochemical properties of the soil around them. Conventionally, when conducting such investigations, the soil is excavated and sampled to analyse these properties in laboratories. As this damages the paved road surface, an alternative method is required. Resistivity is a significant physical property measured when investigating the corrosion risk of underground pipelines. Therefore, if geophysical exploration can facilitate the investigation of soil resistivity from the ground surface, it will play a key role in the renewal planning of water pipes. Traditionally, geophysical methods such as electrical and electromagnetic exploration have been used for measuring subsurface resistivity. Electrical exploration is a robust and noise‐tolerant method; however, it requires electrode installation. Most roads over the pipelines are paved, making conventional electrical exploration using metal electrodes a challenging task. Therefore, the Geological Survey of Japan, the National Institute of Advanced Industrial Science and Technology, has developed a very‐low‐frequency band alternating current electrical surveying technique that uses water‐saturated polyvinyl alcohol sponge electrodes. In this technique, electrodes are placed on an asphalt or concrete paved surface and the electrode measures the soil resistivity profile and detects the corrosive soil distribution without damaging the paved surface. Moreover, we improved this equipment to enable vertical electrical survey of numerous points and acquired data for 740 m of the survey line in 1 day at Maborikaigan coast in Yokosuka City. We found that the resistivity values varied with the depths and locations of the buried water pipes. These variations indicated that surveys and evaluations on long survey lines along water pipe burial routes are essential for risk management in water pipelines. [ABSTRACT FROM AUTHOR]

It is well known that one drawback for stress-ribbon bridges can be that significant horizontal reactions at the abutment can be generated and that they have low flexural stiffness. The latter prevents them from being used as roadway bridges. A new hybrid structure of stress-ribbon deck and truss has been proposed and was adopted in the construction of Nozomi Bridge in Japan, a roadway bridge opened to traffic in 2003. Static and dynamic behaviours of the hybrid structure have been studied analytically and experimentally. The results show that the hybrid bridge has advantages over the stress-ribbon deck bridge as it generates much less horizontal force in suspension cables and has higher flexural stiffness, suitable for use as a roadway bridge, and that the hybrid bridge has advantages over the truss bridge since it can be constructed without extensive falsework and without large erection equipment. In this paper, at first, the hybrid structure is described, then analytical and test results are used to show its static and dynamic characteristics, and finally the construction of Nozomi Bridge is outlined. [ABSTRACT FROM AUTHOR]

Japan Standard Time is an average atomic time generated by a group of Cs clocks at NICT. Several years ago, a problem was found in the timescale, that is, the frequency change by the removal of a clock from the group. The reason turned out to be improper clock-rate estimation of each Cs clock. We fixed the problem by revising the clock-rate estimation method. After this revision, the frequency change on clock removal became small. We also derived a formula to express the frequency change of the timescale by using the data of the removed clock. In some simulations and actual Japan Standard Time, this formula demonstrated its validity for estimating the frequency change. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 157(1): 29–37, 2006; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/eej.20384 [ABSTRACT FROM AUTHOR]