Jennifer McManis

A QoS-aware adaptive Web-based system

This paper presents the framework for a QoS-aware adaptive Web-based system (QoSAS) that adapts Web content based on both user-perceived-QoS and user interests related to the Web content. The architecture of the QoSAS includes a novel perceived performance model (PPM) that models user-perceived performance features via different QoS metrics and suggests content constraints in order to improve the perceived performance. The PPM stereotype-based mathematical model is presented in detail as well as preliminary simulation test results. These results demonstrate that the PPM helps the QoSAS to improve the user satisfaction.

A Multi-Agent Based Vehicles Re-routing System for Unexpected Traffic Congestion Avoidance

As urbanization has been spreading across the world for decades, the traffic congestion problem becomes increasingly serious in most of the major cities. Among the root causes of urban traffic congestion, en route events are the main source of the sudden increase of the road traffic load, especially during peak hours. The current solutions, such as on-board navigation systems for individual vehicles, can only provide optimal routes using current traffic data without considering any traffic changes in the future. Those solutions are thus unable to provide a better alternative route quickly enough if an unexpected congestion occurs. Moreover, using the same alternative routes may lead to new bottlenecks that cannot be avoided. Thus a global traffic load balance cannot be achieved. To deal with these problems, we propose a Multi Agent System (MAS) that can achieve a trade-off between the individual and global benefits by giving the vehicles optimal turn suggestions to bypass a blocked road ahead. The simulation results show that our strategy achieves a substantial gain in average trip time reduction under realistic scenarios. Moreover, the negative impact of selfish re-routing is investigated to show the importance of altruistic re-routing applied in our strategy.

Quality of Experience-LAOS: create once, use many, use anywhere

This paper proposes QoE-LAOS, a Quality of Experience-oriented adaptive authoring model that enables performance-aware adaptation. It extends the existing LAOS authoring model in order to consider display and delivery performance issues. QoE-LAOS involves the addition of three new QoE sublayers: QoE Content Features sublayer, QoE Characteristics sublayer and QoE Rules sublayer. These proposed QoE sublayers are deployed at LAOSs Domain, Adaptation and Presentation Models, respectively. This paper formalises and exemplifies QoE-LAOS and discusses authoring-related issues in relation to each new sublayer.

Location-Aware Chord-Based Overlay for Wireless Mesh Networks

Wireless mesh networks (WMNs) have been widely set up for last-mile network connectivity due to their flexibility, ease of use, and low-cost deployment. When used in conjunction with peer-to-peer data transfer solutions, many innovative applications and services, such as distributed storage, distributed resource sharing, and live TV broadcasting, can be deployed with no centralized administration. However, to achieve good quality of service in wireless environments, it is important that the associated peer-to-peer overlay is not only aware of the availability but of the location of its peers and services as well. This paper proposes a wireless location-aware Chord-based overlay mechanism for WMNs (WILCO) based on a novel geographical multilevel identification (ID) mapping and an improved finger table. The proposed scheme exploits the location information of mesh routers (MRs) to decrease the number of hops that the overlay messages traverse in the physical topology. In comparison with the original Chord, the WILCO mechanism has significant benefits: It reduces the number of lookup messages, has symmetric lookup on keys in both the forward and backward directions of a Chord ring, and achieves a stretch factor of O(1). Simulation results show how the proposed scheme outperforms the original Chord and the state-of-the-art MeshChord in terms of lookup efficiency and how it significantly reduces the overlay message overhead.

The value of qoe-based adaptation approach in educational hypermedia: empirical evaluation

This paper reports the results of a comparison-based empirical study on the applicability of the end-user Quality of Experience-based content adaptation mechanism in adaptive educational hypermedia. The focus of the paper will be the experiment itself: the initial settings, testing scenarios and the results. We will show that for low bit rate connections the QoE-based adaptation decreases study session time, information processing time per page and the number of re-visits to a page, it maintains similar learning outcomes while also improving the user quality of experience and satisfaction with the system. Finally we will comment on the results and interpret them.

The Influence of Web Page Images on the Performance of Web Servers

In recent years World Wide Web traffic has shown phenomenal growth. The main causes are the continuing increase in the number of people navigating the Internet and the creation of millions of new Web sites. In addition, the structure of Web pages has become more complex, including not only HTML files but also other components. This has affected both the download times of Web pages and the network bandwidth required. The goal of our research is to monitor the download times of Web pages from different Web sites, and to find out to what extent the images contained in these Web pages influence these times. We also suggest some possible ways of decreasing the bandwidth requirements and download times of complex Web pages.

Comprehensive performance analysis and comparison of vehicles routing algorithms in smart cities

Due to the severe impact of road traffic congestion on both economy and environment, several vehicles routing algorithms have been proposed to optimize travelers itinerary based on real-time traffic feeds or historical data. However, their evaluation methodologies are not as compelling as their key design idea because none of them had been tested under both real transportation map and real traffic data. In this paper, we conduct a deep performance analysis and comparison of four typical vehicles routing algorithms under various scalability levels (i.e. trip length and traffic load) based on realistic transportation simulation. The ultimate goal of this work is to suggest the most suitable routing algorithm to use in different transportation scenarios, so that it can provide a valuable reference for both traffic managers and researchers when they deploy or optimize a large scale centralized Traffic Management System (TMS). The obtained simulation results reveal that dynamic A* is the best routing algorithm if the TMS has sufficient memory or storage capacities, otherwise static A* is also a great alternative.

A location coordinate-based video delivery scheme over wireless mesh networks

Abstract In this mobile-centric era, users expect ubiquitous access at low cost to an ever increasing range of applications requiring increasingly high data connection speeds. Wireless Mesh Network (WMN) technology provides support for data access over a relatively large area at a modest cost while also being easy and flexible to deploy. Unfortunately, WMN performance is sensitive to load, and applications such as video on demand are likely to stress the network. In response to this, approaches to balance traffic load, such as peer-to-peer solutions are very promising. However, in order to work efficiently, these solutions require not only availability awareness, but also knowledge about location of peers and services. This paper presents a wireless coordinate-based location-aware overlay mechanism for locating and retrieving requested video segments from the nearest peers in order to improve retrieved video quality in WMN. In comparison to the original overlay schemes, our mechanism has significant benefits in both overlay communication efficiency and data retrieval efficiency. Simulation results in both regular and random video segment placement scenarios show how the proposed peer-to-peer video delivery solution for WMN outperforms existing state-of-the-art solutions in terms of video quality and packet loss with different background traffic loads and replication rates.

User location-aware video delivery over Wireless Mesh Networks

Wireless Mesh Networks (WMN) have been widely deployed for last-mile network connectivity due to their flexibility, ease of use and low-cost deployment. When used in conjunction with peer-to-peer data transfer solutions, many innovative applications and services such as distributed storage, resource sharing and live video delivery can be deployed without any centralized administration. However, in order to achieve good quality of service in wireless environments, it is important that the associated peer-to-peer overlay is not only aware of the availability, but also of the location, of its peers and services. Focusing on the quality of video delivery, this paper first presents a wireless location-aware Chord-based overlay mechanism for WMN (WILCO) based on a novel geographical multi-level ID mapping and an improved finger table. Then, a novel segment seeking algorithm is proposed to make use of the location-awareness of the associated peer-to-peer overlay to locate and retrieve requested video segments from the nearest peers in order to improve video quality. Simulation results show how the proposed peer-to-peer video delivery solution for WMN outperforms existing state-of-the-art solutions in terms of video quality.

Developing intelligent software interface for wireless monitoring of vehicle speed and management of associated data

The aim of this work is to develop an intelligent wireless system for monitoring vehicle speed, identify speeding vehicles and imposing penalty for the speeding offenders. A prototype system has been developed in a laboratory environment to generate random speed data using a mechanical wheel (acts as a vehicle), measure the speed data with a Shimmer wireless sensor and transfer the data wirelessly to a server computer for further analysis. Software interface has been developed using Java based socket-programming to monitor the vehicle speed in a server computer and to send the data associated with a speeding vehicle to a remotely placed client computer. The functionality of the software has been tested by experimenting different traffic scenarios. If the vehicle speed is higher than the set speed limit for the road, the system automatically detects it and generates a report with the time of speeding, vehicle number, vehicle speed, etc. The report is saved in a central database (client computer) in order to take further necessary actions for the speeding offender. The experimental evaluation results show that the system can measure and monitor the vehicle speeds wirelessly and manage the speeding data automatically.