Date Completed: December 2005
Introduction to the project:
The Vigenere cipher is a cipher based on using successively shifted alphabets, a different shifted alphabet for each of the 26 English letters.
The carried out task: Writing a program in Java that ciphers and deciphers messages. The system will take a text file, a keyword, and the desired operation (ciphering or deciphering) as inputs from its user. The output of the system consists of the creation and display of original and ciphered/deciphered files.
Date Completed: May 2005
This project builds on the work that went to the implementation part of my B.S. thesis. It covers technologies such as: Session Initiation Protocol, DiffServ QoS Architecture, SIP Network Modules Development, and Network Simulation. I have written a research paper based on the outcomes of this project with the title: “Utilizing DiffServ and SIP Contact Header for Real-time Fax Traffic Engineering”
Abstract—This paper focuses on the transmission of real-time fax in IP networks. For this purpose, the best current practices, i.e., utilization of the Session Initiation Protocol (SIP) as the signaling protocol along with ITU-T T.38 recommendation, are adopted. Two traffic engineering measures: utilization of SIP contact header and DiffServ QoS architecture, are proposed to streamline the implementation of the real-time FoIP. Network simulation results show that the proposed architecture, compared to the “Best Effort” service, has much less transmission time and jitter, and packets received are in correct sequence. Moreover, SIP contact header reduces load on network’s specialized resources. Therefore, this layout is a viable alternative for traditional PSTN fax.
Please click here to download the full paper.
Please click here to download the PowerPoint presentation of the paper.
The paper was accepted and presented at:
18th Annual Canadian Conference on Electrical and Computer Engineering, CCECE05, May 1-4, 2005, Saskatoon Inn, Saskatoon, Saskatchewan, Canada Please click here to download the conference program.
J-Sim network simulator has been utilized in this project. Please click here to download the simulation files.
Date Completed: September 18, 2003
Fading is one of the important obstacles which limits the wireless transmission. Deep fading will cause loss of signal at the receiver. The transmitted signal will arrive at the receiver antenna through multiple paths which causes what is known as multipath fading. Each path has its own delay and attenuation and the received signal amplitude is the collective effect of the signals arrived through different paths.
Date Completed: September 03, 2003
The way that this array calculates the inverted matrix has been thoroughly studied in this paper: "Conical Systolic Array for Matrix Inversion" by H.S.Shahhoseini, A.Khayatzadeh, and M.Naderi (The paper). Herein, I explain the structure of the simulator program which was written by me with C++ language (2800+ LOC).
The mentioned conical systolic array (CSA) uses three types of processing elements (PEs). Each PE has been defined as an object in C++. For writing the program as modular as possible and taking advantage of virtual functions and also gathering the common functionalities of the PEs, a base class with the name of PE has been defined. The three types of PEs have been derived from this base class using public inheritance and the exclusive functionalities of each PE have been implemented in the respective class. These classes have been named according to their shapes in the paper as: EllipticPE, CircularPE, SquarePE. It should be mentioned that all four classes have been implemented regardless of the matrix dimension but due to some synchronization difficulties in one of the clock calculations, the main() function has some irregularities which prevents its generalization to any matrix dimension and in its current state, it is capable of matrix inversion calculation for a 3×3 matrix. The issue was under consideration of the authors of the paper but in the mean time, I was asked to conclude the project; in case that the problem is resolved, only the main() function will need modifications and the PEs' implementations won't need further changes.
Date Completed: August 05, 2003
The following papers are the results of a cooperation between Dr.Lotfi, the antenna and communications circuits labs instructor, and I. My work, for the main part, was helping in the implementation of the optimization algorithms in the projects and also comparing the obtained results with the ones produced by HP-HFSS software. I also had the opportunity to consult with Prof. Hojjat Kashani ,my Antenna course instructor, in the areas of antennas and microwave devices. The results of the application of the mentioned optimization techniques to some electromagnetic problems are documented in the following papers.
Date Completed: June 09, 2003
This project has been conducted in a teamwork manner. Some important concepts of an introductory course on DSP were chosen. First, few were responsible for implementing the code in Matlab using M-files, and at the next stage, others were responsible for transferring the code to GUIs so that the users can enjoy the comfort of windows-based execution. This package was supposed to serve as an educational aid package for the DSP course at MS level and the book “Discrete-time signal processing” by: Alan V. Oppenheim, Roland W. Schafer, and John R. Buck was chosen as the reference.