Mirrors are often studied for camera calibration since they provide symmetric relationship for object which can guarantee synchronization in multiple views. However, it is sometimes difficult to compute the reflection matrices of mirrors. This thesis aims to solve the problem of camera calibration and shape recovery from a two-mirror system which is able to generate five views of an object. It firstly studies the similarity relationship of the motion formed by the five views in two-mirror system with the circular motion. It is shown that the motion formed by the five views can be regarded as two circular motions so that we can avoid computing the reflection matrices of mirrors. This thesis then shows the most important problem which is to recover the vanishing line of rotation plane and the imaged circular points by two unknown equal angles via metric rectification. After that, it is easy to recover the imaged rotation axis and the vanishing points X-axis via imaged circular points.

Zinc alloys have emerged as promising biodegradable metals thanks to their critical physiological roles and encouraging degradation behavior. In this study, calcium phosphate (CaP) coatings were made on micro-arc oxidized Zn alloy using hydrothermal treatment (HT), which was motivated by the CaP-based minerals in natural bone tissue. The coating morphology was optimized by controlling the HT time, resulting in a homogeneous micro-CaP coating structure. The CaP coating significantly increased the cell viability and adhesion of MC3T3-E1 preosteoblasts and L-929 cells. Compared with the control group, the cell toxicity of the samples after MAO-HT was less, the number of cells was more, and the morphology was complete. Cell adhesion showed that the distribution of cells increased with the increase of HT time. In addition, the CaP coating significantly reduced the Zn ion release from the bulk material during the degradation process, resulting in a much lower Zn concentration and pH change in the surrounding environment. The micro-CaP coating structure and the regulated release of zinc ions are primarily responsible for the enhanced cytocompatibility and biomineralization of CaP-coated Zn biomaterials. In summary, the CaP coating on Zn-based biomaterial appears to be a viable approach to enhance its biocompatibility and to control its degradation rate. After that, the biocompatibility of the material can be improved by controlling the surface morphology of the material to adapt to the complex human environment.

No abstract

No abstract