This thesis presents a reliable multiscale multiphysics model to analyze failure induced by alkali-silica reaction (ASR) as well as by weak properties of interfacial transition zone (ITZ) in concrete. The mesostructure of concrete consists of aggregates with random distribution embedded in a homogenized hardened cement paste (HCP) as well as the interface elements with zero-thickness as a representation of the ITZ. One scale lower, the microstructure of concrete is represented by the microstructure of HCP obtained from three-dimensional computer-tomography scans, including hydration products, unhydrated residual clinker and micropores.
Compressive Sensing (CS) has transformed sampling methods by selecting suitable sensing domains, constraining source information characteristics, and utilizing nonlinear solvers for recovery. CS-based Imaging (CSI) cameras can generate an N pixel image using only M measurements, where M is significantly less than N, and they are not limited by sensor bandwidth when the target image is k-sparse or compressible. To ensure the integrity and authenticity of CS-based images, an authentication mechanism is essential. This dissertation introduces an authenticated CSI system utilizing the Compressive Sensing based Message Authentication Code (CSMAC) mechanism, which is integrated into the imaging process through a redundant secure matrix. The extraction mechanism reduces data size and supports a restricted tolerance property. A pre-trained threshold allows the verifier to accommodate a specific level of recovery noise while detecting content modifications. Additionally, an authenticated encrypted CSI mechanism is proposed to combine authentication, encryption, compression, and sensing in a single step. Given the subpar data compression performance of CS-based images, this study suggests improvements for the authenticated encrypted CSI mechanism. Simulated results demonstrate that CSI is computationally secure for confidentiality, sensitive to content-based tampering, and achieves approximately a 20% lower bit-rate for acceptable image
Presents a combined view of content and wireless technologies useful to both the industry and academiaOffers a good mix of theory and practice to understand the internal working of the wireless/mobile content delivery networksBridges the gap between the wireless and content research communitiesFocuses not only on the latest technology enablers for speedier content delivery in the mobile Internet, but also on how to integrate them to provide workable end-to-end solutions
