and application of renewable energy system, power quality; Theory and New Technology of Electrical Engineering: Basic theory of electromagnetic field and its numerical calculation, electromagnetic measurement, wireless transmission of power energy, fault diagnosis based on electromagnetic theory. Department of Mathematical Sciences The Department of Mathematical Sciences (DMS) was established in 1927. In 1952, Tsinghua DMS was merged with the Peking University Department of Mathematical Sciences. Then in 1979 it was renamed "Department of Applied Mathematics", and renamed again in 1999 to its current title. Tsinghua DMS has three institutes at present, the institute of Pure Mathematics which has 27 faculty members, the Institute of Applied Mathematics and Probability and Statistics which has 27 faculty members, and the Institute of Computational Mathematics and Operations Research which has 20 faculty members. There are currently about 400 undergraduate students and 200 graduate students. Department of Precision Instrument The Department of Precision Instrument was called the Department of Precision Instrument and Machine Manufacturing in 1960 when it was separated out from the Department of Machine Manufacturing to be an independent department. Later, in 1971, it was renamed the Department of Precision Instrument. The mission of the Department of Precision Instrument at Tsinghua University, as its dean said, is "supporting the national development and improving the people’s well-being." Research Research in the Department of Precision Instrument is divided to four main parts, led by its four research institutes: the Institute of Opto-electronic Engineering, the Institute of Instrument Science and Technology, the Engineering Research Center for Navigation Technology, and the Center for Photonics and Electronics. At the same time, the Department of Precision Instrument has three key laboratories: the State Key Laboratory of Tribology, the State Key Laboratory of Precision Measurement Technology and Instruments, and the Key Laboratory of High-accuracy Inertial Instrument and System. It also has two national engineering research centers, which are the National Engineering Research Center of Optical Disk and the CIMS National Engineering Research Center. The Institute of Opto-electronic Engineering The Institute of Opto-electronic Engineering (IOEE) was established in 1958. It obtained the Chinese government's authorization to offer PhD program in 1981 and the approval to build the post-doctoral research site in 1988. The research of the IOEE covers opto-electronic instruments, precision metrology and measurement, modern optical information processing, the theory and components of binary optics, and the birefringent frequency-splitting lasers. Several famous scientists work in the IOEE, including Professor Guofan Jin,