In this paper, first the aging level of Stone Mastic Asphalt (SMA): one of the widely applied asphalt mixture types for highway construction in South Korea, was analysed then those aging effects on various performance characteristics were studied. Then, a suitable methodology for improving performance on real asphalt pavement construction site was recommended. To fulfil the objective, Gel-Permeation Chromatography (GPC) experimental work was performed on various aged SMA mixtures by measuring Large Molecular Size (LMS) then the Absolute Viscosity (AV) value was predicted based on the findings in the previous step. As results, it was found that types of performance change on aged asphalt binders could be estimated by computed Estimated Absolute Viscosity (EAV) values. It also should be mentioned that the performances of tested SMA mixture presented negative trend after aging effect increases; even though the performance deterioration level of SMA is lower than that of regular Dense Grade Asphalt (DGA) mixture, which means proper reactions are recommended to keep its quality. Moreover, better resistance against aging effect was found by applying Hydrated-Lime (HL) or Low Density Poly-Ethylene (LDPE) compared to any other additives on asphalt mixtures. A unique Aging Quantity (AQ) model for SMA mixtures was developed by using two factors: collected aging time data set from field (and/or laboratory) and AV values based on different temperature conditions. The Predicted Absolute Viscosity (PAV) on SMA mixtures was computed by using the introduced AQ model then the aging level of asphalt binder was estimated as a final step. Additionally, five performance characteristics of asphalt binder: Dynamic Shear Rheometer(DSR) high temperature limit, Bending Beam Rheometer (BBR) low temperature limit, G*/sinδ, Creep stiffness, and m-value, were analysed. The value of AV showed the best performance for predicting and representing aging level. Finally, the aging level of given asphalt mixtures in the field can be easily predicted by choosing one of three approaches presented in this research. It can be concluded that the performance of asphalt pavement can be increased by selecting proper materials and performance prediction methodologies introduced in this study. However, only limited number of specimens were considered in this study due to limit of raw materials and laboratory equipment condition. Therefore, extensive experimental works with various types of asphalt materials are recommended for strengthen findings in this thesis as a future research.

In this study, we constructed viral vector for soybean by using Soybean yellow common mosaic virus (SYCMV) infecting both Glycine max and Glycine soja. SYCMV-derived viral vector was tested to use as Virus-induced gene silencing (VIGS) vector for functional analysis of soybean genes and as protein expression vector for foreign protein expression. In vitro transcript with 5’ cap analog m7GpppG from a full-length infectious vector of SYCMV driven by T7 promoter was inoculated to soybean to test infectivity of the clone (pSYCMVT7-full). 5’-capped transcript was able to infect soybean plants. The symptoms observed in soybean plants infected by either the vector or the sap from SYCMV-infected leaves were indistinguishable, suggesting that the vector had an equal biological activity shown by virus itself. To further utilize the vector, an additional DNA-based vector was constructed. The full-length cDNA was inserted into a binary vector flanked by CaMV 35S promoter and the nopaline synthase terminator (pSYCMV35S-full). To test if the vector infects soybean and subsequently induces gene silencing, we prepared two constructs containing fragments of Phytoene desaturase (PDS) gene (pSYCMV35S-PDS1) and small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcS) gene (pSYCMV35S-rbcS2) from soybean plant. Plants infiltrated with the constructs through Agrobacterium-mediated method showed distinct symptoms such as photobleaching in plants infiltrated with pSYCMV-PDS1 and pale green or yellowing in plants infiltrated with pSYCMV-rbcS2. In addition, down-regulations of mRNA levels of two genes were confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). To test if the vector can be used for foreign protein expression in soybean plants, we prepared a construct encoding amino acids 135-160 of VP1 FMDV serotype O1 Campos (O1C) (pSYCMV35S-FMDV). Plants infiltrated with the construct through Agrobacterium-mediated method showed that soybean plant infiltrated with pSYCMV35S-FMDV only was detected by Western blotting using O1C antibody. These results support that SYCMV-derived viral vector can be used as VIGS vector or protein expression vector in soybean plants.