Geophysics is an area of science that describes earth media based on their physical properties. Specifically, exploration geophysics has mainly been applied to locate natural resources (hydrocarbon, natural gas, gas hydrate, mineral resources and ground water under the ground or seabed), to evaluate civil engineering sites (including detection of cavities under road surface), and to resolve environmental problems (e.g., monitoring carbon capture and storage sites), etc. Most of geophysical methods, such as gravity, magnetic, electrical, and seismic methods, are based on data acquisition, processing, and interpretation. Our studies focus on developing new data processing techniques such as modeling and inversion algorithms to present high-resolution subsurface images from field data. We have developed various kinds of seismic modeling and inversion algorithms for oil and gas exploration. Recently, our research topics were extended to electrical resistivity and electromagnetic methods including GPR. Our research projects are about developing seismic data processing and interpretation techniques for conventional and unconventional oil and gas exploration, developing 3D magnetotelluric modeling and inversion techniques for analysis of focal depth of earthquakes as a nuclear safety research program, evaluating geophysical techniques to locate cavities under road surface, etc.