由于电学、磁学、电子学以及计算机在内的领域中的工程已经历了重大的技术重点转移。其一是由电力传输与旋转机械向电子学的转移；其二是由电子管向半导体以及由分立元件电路向集成电路的转移；其三是由模拟电路向数字电路的转移；其四是由固定的向可编程数字硬件的转移。-Because of Electricity, magnetism, electronics and computer, including in the field of engineering has gone through a major technological shift in emphasis. One is by the power transmission and rotating machinery to the electronic transfer　the other is from the tube to the semiconductor and discrete components from circuit to circuit transfer　The third is from analog to digital circuits circuit transfer　the fourth is from a fixed to the transfer of programmable digital hardware.