Informatics Publishing Limited

A. Amrou ¹, K. Maly ¹, M. Zubair ¹

Affiliations
1 Department of Computer Science, Old Dominion University, 4700 Elkhron Ave, Ste 3300, Norfolk, VA 23529, US

Abstract

Despite the creation of many digital libraries, there exists considerable untapped content with individuals in diverse communities. One major hindrance to dissemination is the centralized frameworks under which digital libraries are organized and deployed, thus limiting their accessibility, particularly in publishing. We have developed Freelib, a peer-to-peer-based digital library, which is self-sustainable and supports evolving communities with diverse interests. Freelib is built upon the existing work in the areas of OAI (Open Archive Initiative), and peer-to-peer and social networks. The key concept of Freelib is to dynamically form virtual communities based on users' common interest. In order to achieve this, the Freelib client analyses user access patterns and connects itself to other clients, the users of which show similar interest. In this paper, we present architecture of Freelib and report on its performance evaluation. We have built an event-based simulator, which enabled us to simulate networks of thousands of users. We study the performance gain of using Freelib over using small-world peer-to-peer networks alone. The performance evaluation shows that Freelib has significant performance gain over those networks in terms of recall, network bandwidth, and search response time, with minimal cost on the part of the end-user of the system.

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M. Arifeen Ali ¹, Mohsin Jamil ¹, Raheel Afzal ¹, Asad Nawaz ¹, Gussan Mufti ¹, M. Zubair ², Syed Omer Gilani ¹

Affiliations
1 School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Sector H-12 Main Campus, Islamabad, PK
2 U. S. Pakistan Centre for Advance Studies in Energy (USPCAS-E), National University of Sciences and Technology (NUST), Sector H-12 Main Campus, Islamabad, PK

Abstract

In this paper we represent a comparison between PID and Proportional resonant controllers for matrix converter used for unbalance load application. The simulation has been done in Matlab Simulink. A linear model transfer function of matrix converter has been taken to be control by Proportional Resonant controller and PID controllers. Various parameters are taken to find out the close loop system stability. First PID controller and then Proportional resonant controller checked for close loop system’s responses. Optimal controller has been suggested on the basis of best performance for reference sinusoidal tracking.

Keywords

Matrix Converter, PID Controller, Proportional Resonant Controller (PR).

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