To incentivize solar panel adaptation, a multitude of solutions are actively being researched. Among these solutions are colored solar cells, using coatings or filters to open the door for more architectural expression. In order to help architects explore these possibilities, it is necessary to enable flexible, fast, and realistic visualization. This work explores the modeling of color-coated photovoltaic cells using a physically based bidirectional reflectance distribution function (BRDF), with a focus on the pyramidically textured structures embedded inside many of these cells. The BRDF is analytically derived, modeling light interactions as recursively specular multiple-scattering. The model is parametric, characterizing the surface using its pyramid density and pyramid slant angle, making it generally applicable to homogeneous pyramidic surfaces with uniform pyramid heights. Evaluation indicates the model closely approximates the behavior of generated references at steep viewing angles. Clear avenues of improvement, including corrections at shallow angles, are discussed within the context of future work.

With the current fast paced growth in the number of devices connected to the internet, many of these having limited computational capability, security concerns are of increasing importance. To meet the necessity of providing secure encryption to constrained devices many lightweight cryptographic schemes have been developed. This paper provides a comparative study of four of these schemes, namely TEA, XTEA, PRESENT and Simon, explaining how they work and discussing their vulnerabilities and performances. This paper specifically considers the performance of Application Specific Integrated Circuit (ASIC) implementations with regards to their size, throughput, power usage and energy usage per bit encrypted. TEA and PRESENT were found to have potentially problematic vulnerabilities, while no attacks on XTEA and Simon are known that do not reduce the number of rounds used during encryption. Simon and PRESENT were found to perform well, while XTEA implementations were found to be too large for constrained devices. Out of the four, Simon seems the most promising for use in constrained devices. As such, further research into its vulnerabilities is advisable.