PRT simulation in an immersive virtual world

Immersive virtual world environments, such as Second LifeTM (SL), have the potential to dramatically improve the process of analyzing usability within technically correct system simulations, long before the system is built. We report our findings with the SL simulation of a Personal Rapid Transit (PRT) system. The SL model and simulation were done according to the original technical specifications. In interacting with this simulation, the system designers were able to identify several usability issues that would have gone unnoticed in a non-immersive simulation environment. Namely: (1) a problem with the design of the offramp to the station; (2) further requirements for the design of the top of the vehicles, so that the suspended track is out of direct sight of the people inside; (3) further safety requirements for dealing with unexpected obstacles along the path. While all of these issues would have been identified upon deployment of the physical prototype, the contribution of our work is to show how usability issues like these can now be identified much earlier, using simulations in a virtual world. Copyright © 2008 ICST

Network traffic characterisation, analysis, modelling and simulation for networked virtual environments

Networked virtual environment (NVE) refers to a distributed software system where a simulation, also known as virtual world, is shared over a data network between several users that can interact with each other and the simulation in real-time. NVE systems are omnipresent in the present globally interconnected world, from entertainment industry, where they are one of the foundations for many video games, to pervasive games that focus on e-learning, e-training or social studies. From this relevance derives the interest in better understanding the nature and internal dynamics of the network tra c that vertebrates these systems, useful in elds such as network infrastructure optimisation or the study of Quality of Service and Quality of Experience related to NVE-based services. The goal of the present work is to deepen into this understanding of NVE network tra c by helping to build network tra c models that accurately describe it and can be used as foundations for tools to assist in some of the research elds enumerated before. First contribution of the present work is a formal characterisation for NVE systems, which provides a tool to determine which systems can be considered as NVE. Based on this characterisation it has been possible to identify numerous systems, such as several video games, that qualify as NVE and have an important associated literature focused on network tra c analysis. The next contribution has been the study of this existing literature from a NVE perspective and the proposal of an analysis pipeline, a structured collection of processes and techniques to de ne microscale network models for NVE tra c. This analysis pipeline has been tested and validated against a study case focused on Open Wonderland (OWL), a framework to build NVE systems of di erent purpose. The analysis pipeline helped to de ned network models from experimental OWL tra c and assessed on their accuracy from a statistical perspective. The last contribution has been the design and implementation of simulation tools based on the above OWL models and the network simulation framework ns-3. The purpose of these simulations was to con rm the validity of the OWL models and the analysis pipeline, as well as providing potential tools to support studies related to NVE network tra c. As a result of this nal contribution, it has been proposed to exploit the parallelisation potential of these simulations through High Throughput Computing techniques and tools, aimed to coordinate massively parallel computing workloads over distributed resources

Vector-field consistency for ad-hoc gaming

Abstract. Developing distributed multiplayer games for ad-hoc networks is challenging. Consistency of the replicated shared state is hard to ensure at a low cost. Current consistency models and middleware systems lack the required adaptability and efficiency when applied to ad-hoc gaming. Hence, developing such robust applications is still a daunting task. We propose i) Vector-Field Consistency (VFC), a new consistency model, and ii) the Mobihoc middleware to ease the programming effort of these games, while ensuring the consistency of replicated objects. VFC unifies i) several forms of consistency enforcement and a multi-dimensional criteria (time, sequence and value) to limit replica divergence, with ii) techniques based on locality-awareness (w.r.t. players position). Mobihoc adopts VFC and provides game programmers the abstractions to manage game state easily and efficiently. A Mobihoc prototype and a demonstrating game were developed and evaluated. The results obtained are very encouraging

The challenge of emergence of virtual property to the traditional legal theory and the corresponding solutions

The emergence and popularity of virtual property has challenged traditional legal theory, especially property and intellectual property theory. Due to the predisposition for a desire of ownership, and the desire for security and certainty in investment, virtual property users should acquire new specific legal protection for their virtual property. This thesis argues that it is needed to establish an independent virtual property theory which could clarify the legal status of virtual property, the types of virtual property right and the allocation of ownership of virtual property in the virtual world. The majority of the current virtual property theories tend to confuse different types of code and content in virtual worlds, equating the underlying software (the building blocks of virtual worlds) and the user generated content (virtual assets). In this sense, this thesis proposes to construct a notion of virtual property through layer theory. The layer theory divides virtual property into three layers, namely infrastructure layer (1), abstraction layer (2) and content layer (3), based on distinguishing between codes which constitute a platform of the virtual world and codes which consist of the user generated content. The infrastructure layer (1) contains the internet service provides’ ISPs’ codes which constitute the platform of the virtual world. This level of virtual property could be considered as the fundamental basis of the operation of the virtual world. At the abstraction layer (2) sits the unique computer code which comprise of the unique items which designed by ISPs but have not transmitted to users in the virtual world. The content layer (3) are the virtual items which are closely relevant to specific individual due to their personal investment and arrangements. Virtual items that sit at the infrastructure layer (1) and abstraction layer (2) should be categorised as ISPs’ virtual property and should be protected as computer software or artistic works created by writing program under current copyright framework. The programmers’ employed by the ISPs are the author of both categorises of virtual property and the ISPs are the first owner of both types of virtual property. However once virtual property combines users’ skill, labour, personal information and other types of investment and arrangement, the added part then should be categorised as users’ virtual property and the ownership should be granted to ordinary users. Theoretically, this thesis defines virtual property as a piece of property which relies on the internet environment provided by ISPs and reflects both the legal relationship between users and ISPs and the relationship between users and others. This thesis also divides virtual property into three categories, the virtual property users get from ISPs directly without further reproduction and creation, the virtual property that contains users’ private information, and the virtual property enrich users’ originality and reproduction which even have not reach the requirement of copyright. Compared with the traditional property right model, taking the complex relationships reflected by virtual property, this thesis argues that virtual property rights granted to users should be a twofold virtual property right. The twofold virtual property rights system adopts what I term ‘restrained-exclusive property rights’ or ‘fundamental property rights’ to describe the ‘rights’ users can claim to regulate the relationship and conflict between them and ISPs, meanwhile ‘relative-exclusive property rights’ or ‘external property rights’ are used to describe owners’ property interests to prevent the infringement from other users. The twofold virtual property rights system will help courts to recognise the exclusive aspect of users’ virtual property right, clarify the property interest over users’ private information, and identify the originality in users’ virtual property. From the legislative perspective, this thesis suggests that virtual property should be explicitly stipulated in the current copyright framework in the UK due to the characteristic of the virtual property. As the ‘Copyright, Designs and Patents Act 1988’ (CDPA) states in s.1 that copyright is a property right. On the other hand, based on the virtual property theory proposed by this thesis, virtual property that sit at the infrastructure layer (1) and abstraction layer (2) should be protected as computer software or artistic works. Therefore, this thesis suggests that users’ virtual property should be regulated by an independent statute entitled ‘The Virtual Property Statute’ which will complement the current CDPA 1988

Kires: a data-centric telerehabilitation system based on kinect

185 p.It is widely accepted that the worldwide demand for rehabilitation services. To meet these needs, there will have to be developed systems of telerehabilitation that will bring services to even the most remote locations, through Internet and related technologies.This thesis is addressing the area of remote health care delivery, in particular telerehabilitation. We present KiReS; a Kinect based telerehabilitation system which covers the needs of physiotherapists in the process of designing, managing and evaluating physiotherapy protocols and sessions and also covers the needs of the users providing them an intuitive and encouraging interface and giving useful feedback to enhance the rehabilitation process. As required for multi-disciplinary projects, physiotherapists were consulted and feedback from patients was incorporated at different development stages.KiReS aims to outcome limitations of other telerehabilitation systems and bring some novel features: 1) A friendly and helpful interaction with the system using Kinect and motivational interfaces based on avatars. 2) Provision of smart data that supports physiotherapists in the therapy design process by: assuring the maintenance of appropriate constraints and selecting for them a set of exercises that are recommended for the user. 3) Monitoring of rehabilitation sessions through an algorithm that evaluates online performed exercises and sets if they have been properly executed. 4) Extensibility, KiReS is designed to be loaded with a broad spectrum of exercises and protocols

Supporting Non-Linear and Non-Continuous Media Access in Peer-to-Peer Multimedia Systems

Ph.DDOCTOR OF PHILOSOPH

DIVE on the internet

This dissertation reports research and development of a platform for Collaborative Virtual Environments (CVEs). It has particularly focused on two major challenges: supporting the rapid development of scalable applications and easing their deployment on the Internet. This work employs a research method based on prototyping and refinement and promotes the use of this method for application development. A number of the solutions herein are in line with other CVE systems. One of the strengths of this work consists in a global approach to the issues raised by CVEs and the recognition that such complex problems are best tackled using a multi-disciplinary approach that understands both user and system requirements. CVE application deployment is aided by an overlay network that is able to complement any IP multicast infrastructure in place. Apart from complementing a weakly deployed worldwide multicast, this infrastructure provides for a certain degree of introspection, remote controlling and visualisation. As such, it forms an important aid in assessing the scalability of running applications. This scalability is further facilitated by specialised object distribution algorithms and an open framework for the implementation of novel partitioning techniques. CVE application development is eased by a scripting language, which enables rapid development and favours experimentation. This scripting language interfaces many aspects of the system and enables the prototyping of distribution-related components as well as user interfaces. It is the key construct of a distributed environment to which components, written in different languages, connect and onto which they operate in a network abstracted manner. The solutions proposed are exemplified and strengthened by three collaborative applications. The Dive room system is a virtual environment modelled after the room metaphor and supporting asynchronous and synchronous cooperative work. WebPath is a companion application to a Web browser that seeks to make the current history of page visits more visible and usable. Finally, the London travel demonstrator supports travellers by providing an environment where they can explore the city, utilise group collaboration facilities, rehearse particular journeys and access tourist information data