FDTD is an electromagnetic field computation method with the ability of considering circuit elements. Traditional lump element method is insufficient for simulating circuit. In this thesis, we use equivalent source method to combine non-linear circuit elements like active devices into the FDTD simulation. The advantages of this is powerful and time-saving. The accuracy of this method is checked of transmission line driving by CMOS circuits. By employing this method, we find that it will increase EMI phenomenon by strengthening current of driving load, and the load of coupling line will affect noise due to impedance mismatch.

Virtual acoustic prototyping (auralization) is the rendering of a virtual sound field that is created from the calculated acoustic response of a modeled structure. Auralization is useful in the design and subjective evaluation of buildings, automobiles, and aircraft. The virtual acoustic prototyping method in this thesis uses finite element modeling (FEM), the equivalent source method (ESM), and head-related transfer functions (HRTFs). A tradeoff exists between the accuracy of the auralization process and the number of equivalent sources (and thus computational power) that are required. The goal of this research is to validate (numerically and subjectively) a virtual acoustic prototyping method for use in structural design; this thesis illustrates the first attempt to apply the aforementioned methods to a structure that represents a typical building or automobile. The structure's acoustics were modeled using FEM, ESM, and HRTFs. A prototype of the modeled structure was built. A 36% correlation was achieved between the model and prototype. Slight variations in boundary conditions caused significant FEM error, but the data represented a typical structure. Psychoacoustic comparison testing was performed to determine the number of equivalent sources that must be used in an auralization to accurately recreate the sound field. The number was found to be dependent on the type of noise that is played to the test subject. A clear relationship between the numerical correlation of two sounds and the percentage of subjects who could hear a difference between those two sounds was established for impulsive, broadband, and engine noises. / Master of Science