8 research outputs found
Enhancing trustability in MMOGs environments
Massively Multiplayer Online Games (MMOGs; e.g., World of Warcraft), virtual worlds
(VW; e.g., Second Life), social networks (e.g., Facebook) strongly demand for more
autonomic, security, and trust mechanisms in a way similar to humans do in the real
life world. As known, this is a difficult matter because trusting in humans and organizations
depends on the perception and experience of each individual, which is difficult to
quantify or measure. In fact, these societal environments lack trust mechanisms similar
to those involved in humans-to-human interactions. Besides, interactions mediated
by compute devices are constantly evolving, requiring trust mechanisms that keep the
pace with the developments and assess risk situations.
In VW/MMOGs, it is widely recognized that users develop trust relationships from their
in-world interactions with others. However, these trust relationships end up not being
represented in the data structures (or databases) of such virtual worlds, though they
sometimes appear associated to reputation and recommendation systems. In addition,
as far as we know, the user is not provided with a personal trust tool to sustain his/her
decision making while he/she interacts with other users in the virtual or game world.
In order to solve this problem, as well as those mentioned above, we propose herein a
formal representation of these personal trust relationships, which are based on avataravatar
interactions. The leading idea is to provide each avatar-impersonated player
with a personal trust tool that follows a distributed trust model, i.e., the trust data is
distributed over the societal network of a given VW/MMOG.
Representing, manipulating, and inferring trust from the user/player point of view certainly
is a grand challenge. When someone meets an unknown individual, the question
is âCan I trust him/her or not?â. It is clear that this requires the user to have access to
a representation of trust about others, but, unless we are using an open source VW/MMOG,
it is difficult ânot to say unfeasibleâ to get access to such data. Even, in an open
source system, a number of users may refuse to pass information about its friends, acquaintances,
or others. Putting together its own data and gathered data obtained from
others, the avatar-impersonated player should be able to come across a trust result
about its current trustee. For the trust assessment method used in this thesis, we use
subjective logic operators and graph search algorithms to undertake such trust inference
about the trustee. The proposed trust inference system has been validated using
a number of OpenSimulator (opensimulator.org) scenarios, which showed an accuracy
increase in evaluating trustability of avatars.
Summing up, our proposal aims thus to introduce a trust theory for virtual worlds, its
trust assessment metrics (e.g., subjective logic) and trust discovery methods (e.g.,
graph search methods), on an individual basis, rather than based on usual centralized
reputation systems. In particular, and unlike other trust discovery methods, our methods
run at interactive rates.MMOGs (Massively Multiplayer Online Games, como por exemplo, World of Warcraft),
mundos virtuais (VW, como por exemplo, o Second Life) e redes sociais (como por exemplo,
Facebook) necessitam de mecanismos de confiança mais autónomos, capazes de
assegurar a segurança e a confiança de uma forma semelhante à que os seres humanos
utilizam na vida real. Como se sabe, esta nĂŁo Ă© uma questĂŁo fĂĄcil. Porque confiar em
seres humanos e ou organizaçÔes depende da percepção e da experiĂȘncia de cada indivĂduo,
o que Ă© difĂcil de quantificar ou medir Ă partida. Na verdade, esses ambientes
sociais carecem dos mecanismos de confiança presentes em interacçÔes humanas presenciais.
Além disso, as interacçÔes mediadas por dispositivos computacionais estão em
constante evolução, necessitando de mecanismos de confiança adequados ao ritmo da
evolução para avaliar situaçÔes de risco.
Em VW/MMOGs, é amplamente reconhecido que os utilizadores desenvolvem relaçÔes
de confiança a partir das suas interacçÔes no mundo com outros. No entanto, essas relaçÔes
de confiança acabam por não ser representadas nas estruturas de dados (ou bases
de dados) do VW/MMOG especĂfico, embora Ă s vezes apareçam associados Ă reputação
e a sistemas de reputação. Além disso, tanto quanto sabemos, ao utilizador não lhe
é facultado nenhum mecanismo que suporte uma ferramenta de confiança individual
para sustentar o seu processo de tomada de decisĂŁo, enquanto ele interage com outros
utilizadores no mundo virtual ou jogo. A fim de resolver este problema, bem como
os mencionados acima, propomos nesta tese uma representação formal para essas relaçÔes
de confiança pessoal, baseada em interacçÔes avatar-avatar. A ideia principal
é fornecer a cada jogador representado por um avatar uma ferramenta de confiança
pessoal que segue um modelo de confiança distribuĂda, ou seja, os dados de confiança
sĂŁo distribuĂdos atravĂ©s da rede social de um determinado VW/MMOG.
Representar, manipular e inferir a confiança do ponto de utilizador/jogador, é certamente
um grande desafio. Quando alguĂ©m encontra um indivĂduo desconhecido, a
pergunta Ă© âPosso confiar ou nĂŁo nele?â. Ă claro que isto requer que o utilizador tenha
acesso a uma representação de confiança sobre os outros, mas, a menos que possamos
usar uma plataforma VW/MMOG de cĂłdigo aberto, Ă© difĂcil â para nĂŁo dizer impossĂvel
â obter acesso aos dados gerados pelos utilizadores. Mesmo em sistemas de cĂłdigo
aberto, um nĂșmero de utilizadores pode recusar partilhar informaçÔes sobre seus amigos,
conhecidos, ou sobre outros. Ao juntar seus prĂłprios dados com os dados obtidos de
outros, o utilizador/jogador representado por um avatar deve ser capaz de produzir uma
avaliação de confiança sobre o utilizador/jogador com o qual se encontra a interagir.
Relativamente ao método de avaliação de confiança empregue nesta tese, utilizamos
lógica subjectiva para a representação da confiança, e também operadores lógicos da
lĂłgica subjectiva juntamente com algoritmos de procura em grafos para empreender
o processo de inferĂȘncia da confiança relativamente a outro utilizador. O sistema de
inferĂȘncia de confiança proposto foi validado atravĂ©s de um nĂșmero de cenĂĄrios Open-Simulator (opensimulator.org), que mostrou um aumento na precisĂŁo na avaliação da
confiança de avatares.
Resumindo, a nossa proposta visa, assim, introduzir uma teoria de confiança para mundos
virtuais, conjuntamente com métricas de avaliação de confiança (por exemplo, a
lógica subjectiva) e em métodos de procura de caminhos de confiança (com por exemplo,
através de métodos de pesquisa em grafos), partindo de uma base individual, em
vez de se basear em sistemas habituais de reputação centralizados. Em particular, e ao
contrårio de outros métodos de determinação do grau de confiança, os nossos métodos
sĂŁo executados em tempo real
Improving Laboratory Learning Outcomes: An Investigation Into the Effect of Contextualising Laboratories Using Virtual Worlds and Remote Laboratories.
This thesis presents research into improving learning outcomes in laboratories. It was hypothesised that domain specific context can aid students in understanding the relationship between a laboratory (as a proxy for reality), the theoretical model being investigated within the laboratory activity and the real world. Specifically, the research addressed whether adding domain context to a laboratory activity could improve students' ability to identify the strengths and limitations of models as predictors of real-world behaviour. The domain context was included in a laboratory activity with the use of a remote radiation lab set within a context-rich virtual world. The empirical investigation used a pretest-posttest control group design to assess whether there was a statistically significant difference in the learning outcome between a treatment group who completed the lab in a contextualised virtual world, and the control group who conducted the activity in an empty virtual world. The results showed that there were no statistically significant differences between the groups and therefore there are cases where contextualising a laboratory activity will not have an effect on students' ability to identify the strengths and limitations of models as predictors of real-world behaviour. This research postulates that previous exposure to the model, the level of awareness students had of the context and the lack time available for reflection may have masked or attenuated the effect of the context. This research has contributed a framework for the analysis and design of domain context in laboratory activities, and an interface for integrating iLabs laboratories into the Open Wonderland virtual world. It has explicitly clarified the relationship between context, labs, models and the real world. Most significantly, this research has contributed knowledge to the field of laboratory learning outcomes and the understanding of how domain context affects laboratory activities
Experimental Evaluation of Growing and Pruning Hyper Basis Function Neural Networks Trained with Extended Information Filter
In this paper we test Extended Information Filter (EIF) for sequential training of Hyper Basis Function Neural Networks with growing and pruning ability (HBF-GP). The HBF neuron allows different scaling of input dimensions to provide better generalization property when dealing with complex nonlinear problems in engineering practice. The main intuition behind HBF is in generalization of Gaussian type of neuron that applies Mahalanobis-like distance as a distance metrics between input training sample and prototype vector. We exploit concept of neuronâs significance and allow growing and pruning of HBF neurons during sequential learning process. From engineerâs perspective, EIF is attractive for training of neural networks because it allows a designer to have scarce initial knowledge of the system/problem. Extensive experimental study shows that HBF neural network trained with EIF achieves same prediction error and compactness of network topology when compared to EKF, but without the need to know initial state uncertainty, which is its main advantage over EKF
Bioinspired metaheuristic algorithms for global optimization
This paper presents concise comparison study of newly developed bioinspired algorithms for global optimization problems. Three different metaheuristic techniques, namely Accelerated Particle Swarm Optimization (APSO), Firefly Algorithm (FA), and Grey Wolf Optimizer (GWO) are investigated and implemented in Matlab environment. These methods are compared on four unimodal and multimodal nonlinear functions in order to find global optimum values. Computational results indicate that GWO outperforms other intelligent techniques, and that all aforementioned algorithms can be successfully used for optimization of continuous functions
Advances in Computer Science and Engineering
The book Advances in Computer Science and Engineering constitutes the revised selection of 23 chapters written by scientists and researchers from all over the world. The chapters cover topics in the scientific fields of Applied Computing Techniques, Innovations in Mechanical Engineering, Electrical Engineering and Applications and Advances in Applied Modeling
An investigation of innovation and knowledge creation in virtual worlds
The Internet and World Wide Web have had, and continue to have, an incredible
impact on our civilization. These technologies have radically influenced the way
that society is organised and the manner in which people around the world
communicate and interact. The structure and function of individual, social,
organisational, economic and political life begin to resemble the digital network
architectures upon which they are increasingly reliant. It is increasingly difficult
to imagine how our âofflineâ world would look or function without the âonlineâ
world; it is becoming less meaningful to distinguish between the âactualâ and the
âvirtualâ. Thus, the major architectural project of the twenty-first century is to
âimagine, build, and enhance an interactive and ever changing cyberspaceâ (LĂ©vy,
1997, p. 10). Virtual worlds are at the forefront of this evolving digital landscape.
Virtual worlds have âcritical implications for business, education, social sciences,
and our society at largeâ (Messinger et al., 2009, p. 204).
This study focuses on the possibilities of virtual worlds in terms of
communication, collaboration, innovation and creativity. The concept of
knowledge creation is at the core of this research. The study shows that scholars
increasingly recognise that knowledge creation, as a socially enacted process,
goes to the very heart of innovation. However, efforts to build upon these insights
have struggled to escape the influence of the information processing paradigm of
old and have failed to move beyond the persistent but problematic
conceptualisation of knowledge creation in terms of tacit and explicit knowledge.
Based on these insights, the study leverages extant research to develop the
conceptual apparatus necessary to carry out an investigation of innovation and
knowledge creation in virtual worlds. The study derives and articulates a set of
definitions (of virtual worlds, innovation, knowledge and knowledge creation) to
guide research. The study also leverages a number of extant theories in order to
develop a preliminary framework to model knowledge creation in virtual worlds.
Using a combination of participant observation and six case studies of innovative
educational projects in Second Life, the study yields a range of insights into the
process of knowledge creation in virtual worlds and into the factors that affect it.
The studyâs contributions to theory are expressed as a series of propositions and
findings and are represented as a revised and empirically grounded theoretical
framework of knowledge creation in virtual worlds. These findings highlight the
importance of prior related knowledge and intrinsic motivation in terms of
shaping and stimulating knowledge creation in virtual worlds. At the same time,
they highlight the importance of meta-knowledge (knowledge about knowledge)
in terms of guiding the knowledge creation process whilst revealing the diversity
of behavioural approaches actually used to create knowledge in virtual worlds
and. This theoretical framework is itself one of the chief contributions of the study
and the analysis explores how it can be used to guide further research in virtual
worlds and on knowledge creation. The studyâs contributions to practice are
presented as actionable guide to simulate knowledge creation in virtual worlds.
This guide utilises a theoretically based classification of four knowledge-creator
archetypes (the sage, the lore master, the artisan, and the apprentice) and derives
an actionable set of behavioural prescriptions for each archetype. The study
concludes with a discussion of the studyâs implications in terms of future
research
Remote access laboratories for preparing STEM teachers: A mixed methods study
Banduraâs self-efficacy theory provided the conceptual framework for this mixed methods investigation of pre-service teachersâ (PSTs) self-efficacy to teach Science, Technology, Engineering and Mathematics (STEM) subjects. The Science Teaching Efficacy Belief Instrument-B (STEBI-B) was modified to create the Technology Teaching Efficacy Belief Instrument (T-TEBI). Pre-test and post-test T-TEBI scores were measured to investigate changes in PSTsâ self-efficacy to teach technology. Interviews and reflections were used to explore the reasons for changes in pre-service teachersâ self-efficacy. This paper reports results from a pilot study using an innovative Remote Access Laboratory system with PSTs