Sharif Digital Repository

For increasing safety of driving, intelligent vehicles in vehicular ad hoc networks (VANETs) communicate with each other by sending announcements. The existence of a system that guarantees the trustworthiness of these announcements seems necessary. The proposed system generating announcements should be preserved from internal and external attackers that attempt to send fake messages. In this thesis, we use a group-based endorsement mechanism based on threshold signatures against internal attackers. We choose NTRUSign as a public key cryptosystem for implementing the Public Key Infrastructure (PKI) for decreasing signature generation and verification times. This approach optimizes the network... 

This research focuses on the robust mobile robot localization exploiting motion information acquired from an optical mouse operating based on optical flow technology. Most techniques of visual motion measurement are based on the well research discipline called “optical flow”. Theoretically, optical flow as a method of localization can be highly accurate, but it is sensitive to the noise and surface texture/optical characteristics and distance variations between the CCD detector and surface. As one could not achieve acceptable results in practical situations, to handle these problems, we propose to attach an acceleration – gyro (INS) sensor on the CCD detector (optical mouse) to improve the...