Sharif Digital Repository

A compact aging model for circuit simulation has been developed by considering all possible trapped carriers within MOSFETs. The hot carrier effect and the N(P)BTI effect are modeled by integrating the substrate current as well as the oxide field change due to the trapped carriers. Additionally, the carriers trapped within the highly resistive drift region are included for high-voltage (HV)-MOSFET modeling. The aging model considers the dynamic trap-density increase as a function of circuit-operation time with dynamically varying stress conditions for each individual MOSFET. A self-consistent solution is obtained by iteratively solving the Poisson equation including the trap density. The... 

A new hybrid approach for dynamic optimization problems with continuous search spaces is presented. The proposed approach hybridizes efficient features of the particle swarm optimization in tracking dynamic changes with a new evolutionary procedure. In the proposed dynamic hybrid PSO (DHPSO) algorithm, the swarm size is varied in a self-regulatory manner. Inspired from the microbial life, the particles can reproduce infants and the old ones die. The infants are especially reproduced by high potential particles and located near the local optimum points, using the quadratic interpolation method. The algorithm is adapted to perform in continuous search spaces, utilizing continuous movement of... 

Nowadays, data outsourcing has become a solution for many organizations especially large scale enterprises due to the high costs of in-house management of the rapidly growing data. Among all security requirements in this context, user access control and its following dynamic changes are of interest. In this paper, we propose an efficient and reliable mechanism to solve this problem in owner-write-users-read applications. A novel solution is introduced to enforce access control on outsourced data using the Chinese Remainder Theorem. The solution allows updating policy changes at a limited cost in terms of both computational power and the number of users' secret keys. Although the server, on...