SI base unit SI base unit The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived. The SI base units and their physical quantities are the meter for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the candela for luminous intensity, and the mole for amount of substance. The SI base units form a set of mutually independent dimensions as required by dimensional analysis commonly employed in science and technology. The names and symbols of SI base
Lee Si-Chen of National Universities of Taiwan (2006 – ) and chair of the University Mobility in Asia and the Pacific (2005 – ). He is also a professor of electrical engineering at the National Taiwan University (1985 - ). He is interested in the scientific research of Chinese Qigong and extrasensory perception. Lee Si-Chen Lee Si-Chen (; born August 13, 1952 in Gangshan (岡山), Taiwan), is a Taiwanese engineer specializing in semiconductors, a researcher in amorphous silicon in the early development in Taiwan, and an IEEE Fellow. He has been a professor of electrical engineering since 1982 and the president of