Sharif Digital Repository

Learning an appropriate distance measure under supervision of side information has become a topic of significant interest within machine learning community. In this paper, we address the problem of metric learning for constrained clustering by considering three important issues: (1) considering importance degree for constraints, (2) preserving the topological structure of data, and (3) preserving some natural distribution properties in the data. This work provides a unified way to handle different issues in constrained clustering by learning an appropriate distance measure. It has modeled the first issue by injecting the importance degree of constraints directly into an objective function.... 

A Mobile Ad Hoc Network (MANET) is an infrastructure-less network composed of mobile devices. In order to meet the foresight of newly developing MANETs, a method of maintaining a real-time flow despite dynamic topology and random movement of users is required. Mobility prediction is one of the keys to successful design of efficient protocols to find stable and reliable routes in MANETs. An important characteristic of a MANET is the distribution of the link distance between communicating users. In this paper a novel mobility model is developed for users of a MANET wandering in an unlimited area and is used to derive an analytical framework to approximate the communication links distance... 

With the growing number of cores, high-performance systems face power challenges due to dominating communication power. Thus, attaining energy efficient high-bandwidth inter-core communication nominates photonic network-on chip as the most promising interconnection paradigm. Although photonic networks pave the way for extremely higher performance communications, their intrinsic susceptibility to thermal fluctuations intimidates reliability of system. This necessitates the development of methodologies to analyze and model thermal effects on network behavior. In this paper, we model temperature fluctuations of optical chips and analyze photonic networks in a holistic approach. We present a... 

Topology control algorithms in mobile ad-hoc networks aim to reduce the power consumption while keeping the topology connected. These algorithms can preserve network resources and increase network capacity. However, few efforts have focused on the issue of topology control in presence of node mobility. One of the notable mobility aware topology control protocols is the "Mobility Aware Distributed Topology Control Protocol". The main drawback of this protocol is on its mobility prediction method. This prediction method assumes linear movements and is unable to cope with sudden changes in the mobile node movements. In this paper, we propose a pattern matching based mobility prediction method... 

Although collaborative distributed simulations and virtual environments (VE) have been an active area of research in the past few years, they have recently gained even more attention due to the emergence of online gaming, emergency simulation and planning systems, and disaster management applications. Such environments combine graphics, haptics, animations and networking to create interactive multimodal worlds that allows participants to collaborate in real-time. Massively Multiplayer Online Gaming (MMOG), perhaps the most widely deployed practical application of distributed virtual environments, allows players to act together concurrently in a virtual world over the Internet. IP...