The morphology and strength of the primordial magnetic field which is generated spontaneously in the early universe are studied for three models: (1) inflation (2) primordial magnetized bubble and (3) primordial turbulence models, We calculate the power spectra of magnetic field that are scale-free and proportional to k1.5,k3~4 and k2/3, respectively. The configurations of magnetic field having these power spectra are visualized. To constrain the present strength of the primordial magnetic field we calculate the anisotropy of the microwave background radiation in Bianchi type I universe with globally homogeneous magnetic field. From the COBE limit of the quadrupole moment of (δT/T)l=2 the present strength of horizen-scale magnetic fields Bp is constrained to be less than 9 × 10-8G.

In maintaining infra-structure, the conventional assessment and maintenance system has focused on safety. As the importance of performance-based assessment increases, considering the performance indices has became essential to assess in perspective of comprehensive evaluation of infrastructure. Therefore, in this study, the conventional evaluation system in Korea and suggested future direction of the maintenance system are analyzed.

In maintaining infra-structure, the conventional assessment and maintenance system has focused on safety. As the importance of performance-based assessment increases, considering the performance indices has became essential to assess in perspective of comprehensive evaluation of infrastructure. Therefore, in this study, the conventional evaluation system in Korea and suggested future direction of the maintenance system are analyzed.