7 research outputs found
Modelling and Design of Resilient Networks under Challenges
Communication networks, in particular the Internet, face a variety of challenges that can disrupt our daily lives resulting in the loss of human lives and significant financial costs in the worst cases. We define challenges as external events that trigger faults that eventually result in service failures. Understanding these challenges accordingly is essential for improvement of the current networks and for designing Future Internet architectures. This dissertation presents a taxonomy of challenges that can help evaluate design choices for the current and Future Internet. Graph models to analyse critical infrastructures are examined and a multilevel graph model is developed to study interdependencies between different networks. Furthermore, graph-theoretic heuristic optimisation algorithms are developed. These heuristic algorithms add links to increase the resilience of networks in the least costly manner and they are computationally less expensive than an exhaustive search algorithm. The performance of networks under random failures, targeted attacks, and correlated area-based challenges are evaluated by the challenge simulation module that we developed. The GpENI Future Internet testbed is used to conduct experiments to evaluate the performance of the heuristic algorithms developed
Previsão e análise da estrutura e dinâmica de redes biológicas
Increasing knowledge about the biological processes that govern the
dynamics of living organisms has fostered a better understanding of the
origin of many diseases as well as the identification of potential therapeutic
targets. Biological systems can be modeled through biological networks,
allowing to apply and explore methods of graph theory in their investigation
and characterization. This work had as main motivation the inference of
patterns and rules that underlie the organization of biological networks.
Through the integration of different types of data, such as gene expression,
interaction between proteins and other biomedical concepts, computational
methods have been developed so that they can be used to predict and study
diseases.
The first contribution, was the characterization a subsystem of the human
protein interactome through the topological properties of the networks that
model it. As a second contribution, an unsupervised method using biological
criteria and network topology was used to improve the understanding of
the genetic mechanisms and risk factors of a disease through co-expression
networks. As a third contribution, a methodology was developed to remove
noise (denoise) in protein networks, to obtain more accurate models, using
the network topology. As a fourth contribution, a supervised methodology
was proposed to model the protein interactome dynamics, using exclusively
the topology of protein interactions networks that are part of the dynamic
model of the system.
The proposed methodologies contribute to the creation of more precise,
static and dynamic biological models through the identification and use of
topological patterns of protein interaction networks, which can be used to
predict and study diseases.O conhecimento crescente sobre os processos biológicos que regem a
dinâmica dos organismos vivos tem potenciado uma melhor compreensão da
origem de muitas doenças, assim como a identificação de potenciais alvos
terapêuticos. Os sistemas biológicos podem ser modelados através de redes
biológicas, permitindo aplicar e explorar métodos da teoria de grafos na sua
investigação e caracterização. Este trabalho teve como principal motivação
a inferência de padrões e de regras que estão subjacentes à organização de
redes biológicas.
Através da integração de diferentes tipos de dados, como a expressão
de genes, interação entre proteínas e outros conceitos biomédicos, foram
desenvolvidos métodos computacionais, para que possam ser usados na
previsão e no estudo de doenças.
Como primeira contribuição, foi proposto um método de caracterização de
um subsistema do interactoma de proteínas humano através das propriedades
topológicas das redes que o modelam. Como segunda contribuição, foi
utilizado um método não supervisionado que utiliza critérios biológicos e
topologia de redes para, através de redes de co-expressão, melhorar a
compreensão dos mecanismos genéticos e dos fatores de risco de uma
doença. Como terceira contribuição, foi desenvolvida uma metodologia
para remover ruído (denoise) em redes de proteínas, para obter modelos
mais precisos, utilizando a topologia das redes. Como quarta contribuição,
propôs-se uma metodologia supervisionada para modelar a dinâmica do
interactoma de proteínas, usando exclusivamente a topologia das redes de
interação de proteínas que fazem parte do modelo dinâmico do sistema.
As metodologias propostas contribuem para a criação de modelos biológicos,
estáticos e dinâmicos, mais precisos, através da identificação e uso de
padrões topológicos das redes de interação de proteínas, que podem ser
usados na previsão e no estudo doenças.Programa Doutoral em Engenharia Informátic
Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes
The book documents 25 papers collected from the Special Issue “Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes”, highlighting recent research trends in complex industrial processes. The book aims to stimulate the research field and be of benefit to readers from both academic institutes and industrial sectors
Application of Geographic Information Systems
The importance of Geographic Information Systems (GIS) can hardly be overemphasized in today’s academic and professional arena. More professionals and academics have been using GIS than ever – urban & regional planners, civil engineers, geographers, spatial economists, sociologists, environmental scientists, criminal justice professionals, political scientists, and alike. As such, it is extremely important to understand the theories and applications of GIS in our teaching, professional work, and research. “The Application of Geographic Information Systems” presents research findings that explain GIS’s applications in different subfields of social sciences. With several case studies conducted in different parts of the world, the book blends together the theories of GIS and their practical implementations in different conditions. It deals with GIS’s application in the broad spectrum of geospatial analysis and modeling, water resources analysis, land use analysis, infrastructure network analysis like transportation and water distribution network, and such. The book is expected to be a useful source of knowledge to the users of GIS who envision its applications in their teaching and research. This easy-to-understand book is surely not the end in itself but a little contribution to toward our understanding of the rich and wonderful subject of GIS