105 research outputs found
Architecture and Implementation of a Trust Model for Pervasive Applications
Collaborative effort to share resources is a significant feature of pervasive computing environments. To achieve secure service discovery and sharing, and to distinguish between malevolent and benevolent entities, trust models must be defined. It is critical to estimate a device\u27s initial trust value because of the transient nature of pervasive smart space; however, most of the prior research work on trust models for pervasive applications used the notion of constant initial trust assignment. In this paper, we design and implement a trust model called DIRT. We categorize services in different security levels and depending on the service requester\u27s context information, we calculate the initial trust value. Our trust value is assigned for each device and for each service. Our overall trust estimation for a service depends on the recommendations of the neighbouring devices, inference from other service-trust values for that device, and direct trust experience. We provide an extensive survey of related work, and we demonstrate the distinguishing features of our proposed model with respect to the existing models. We implement a healthcare-monitoring application and a location-based service prototype over DIRT. We also provide a performance analysis of the model with respect to some of its important characteristics tested in various scenarios
Protocol for a Systematic Literature Review on Security-related Research in Ubiquitous Computing
Context: This protocol is as a supplementary document to our review paper that investigates security-related challenges and solutions that have occurred during the past decade (from January 2003 to December 2013).
Objectives: The objective of this systematic review is to identify security-related challenges, security goals and defenses in ubiquitous computing by answering to three main research questions. First, demographic data and trends will be given by analyzing where, when and by whom the research has been carried out. Second, we will identify security goals that occur in ubiquitous computing, along with attacks, vulnerabilities and threats that have motivated the research. Finally, we will examine the differences in addressing security in ubiquitous computing with those in traditional distributed systems.
Method: In order to provide an overview of security-related challenges, goals and solutions proposed in the literature, we will use a systematic literature review (SLR). This protocol describes the steps which are to be taken in order to identify papers relevant to the objective of our review. The first phase of the method includes planning, in which we define the scope of our review by identifying the main research questions, search procedure, as well as inclusion and exclusion criteria. Data extracted from the relevant papers are to be used in the second phase of the method, data synthesis, to answer our research questions. The review will end by reporting on the results.
Results and conclusions: The expected results of the review should provide an overview of attacks, vulnerabilities and threats that occur in ubiquitous computing and that have motivated the research in the last decade. Moreover, the review will indicate which security goals are gaining on their significance in the era of ubiquitous computing and provide a categorization of the security-related countermeasures, mechanisms and techniques found in the literature. (authors' abstract)Series: Working Papers on Information Systems, Information Business and Operation
Design and Implementation of S-MARKS: A Secure Middleware for Pervasive Computing Applications
As portable devices have become a part of our everyday life, more people are unknowingly participating in a pervasive computing environment. People engage with not a single device for a specific purpose but many devices interacting with each other in the course of ordinary activity. With such prevalence of pervasive technology, the interaction between portable devices needs to be continuous and imperceptible to device users. Pervasive computing requires a small, scalable and robust network which relies heavily on the middleware to resolve communication and security issues. In this paper, we present the design and implementation of S-MARKS which incorporates device validation, resource discovery and a privacy module
Con-Resistant Trust for Improved Reliability in a Smart Grid Special Protection System
This paper applies a con-resistant trust mechanism to improve the performance of a communications-based special protection system to enhance its effectiveness and resiliency. Smart grids incorporate modern information technologies to increase reliability and efficiency through better situational awareness. However, with the benefits of this new technology come the added risks associated with threats and vulnerabilities to the technology and to the critical infrastructure it supports. The research in this paper uses con-resistant trust to quickly identify malicious or malfunctioning (untrustworthy) protection system nodes to mitigate instabilities. The con-resistant trust mechanism allows protection system nodes to make trust assessments based on the node\u27s cooperative and defective behaviors. These behaviors are observed via frequency readings which are prediodically reported. The trust architecture is tested in experiments by comparing a simulated special protection system with a con-resistant trust mechanism to one without the mechanism via an analysis of the variance statistical model. Simulation results show promise for the proposed con-resistant trust mechanism. © IEE
Collaborative networks in ambient assisted living
Tese de doutoramento em InformáticaCollaborative Work plays an important role in today’s organizations, especially
in areas where decisions must be made. However, any decision that involves a
collective or group of decision makers is, by itself, complex, but is becoming recurrent
in recent years. In this work we present the VirtualECare project, an intelligent multiagent
system able to monitor, interact and serve its customers, in need of care
services. In last year’s there has been a substantially increase on the number of
people needed of intensive care, especially among the elderly, a phenomenon that is
related to population ageing. However, this is becoming not exclusive of the elderly,
as diseases like obesity, diabetes and blood pressure have been increasing among
young adults. This is a new reality that needs to be dealt by the health sector,
particularly by the public one. Given this scenario, the importance of finding new and
cost effective ways for health care delivery are of particular importance, especially
when it is believed that they should not be removed from their natural “habitat”.
Following this line of thinking, the VirtualECare project will be presented, like similar
ones that preceded it. On the other hand, this is a growing interest in combining the
advances in information society ‐ computing, telecommunications and presentation –
in order to create Group Decision Support Systems (GDSSs). Indeed, the new
economy, along with increased competition in today’s complex business
environments, takes the companies to seek complementarities in order to increase
competitiveness and reduce risks. Under these settings, planning takes a major role in
a company life. However, effective planning depends on the generation and analysis
of ideas (innovative or not) and, as a result, the idea generation and management
processes are crucial. In particular if is believed that the use of GDSS in the healthcare
arena will allow professionals to achieve better results in the analysis of one’s
Electronically Clinical Profile (ECP). This achievement is vital, regarding the explosion
of knowledge and skills, together with the need to use limited resources and get the expected outcomes.Hoje em dia, o Trabalho Colaborativo desempenha um papel deveras
importante na maioria das organizações, especialmente em áreas em que decisões
têm de ser tomadas. No entanto, e muito embora comece a ser recorrente, qualquer
decisão que envolva um grupo colectivo de decisores é, por si só, complexa. Nesta
tese apresenta‐se o projecto VirtualECare, um sistema inteligente multi‐agente capaz
de monitorar, interagir e servir os seus utilizadores, com necessidades de cuidados de
saúde. Nos últimos anos têm‐se verificado um aumento substancial no número de
pessoas necessitadas de cuidados intensivos, especialmente entre a população mais
envelhecida, um fenómeno directamente relacionado com o envelhecimento gradual
da população. No entanto, esta é uma problemática que começa a deixar de estar
exclusivamente associada aos idosos, uma vez que, doenças como a obesidade,
diabetes e a pressão arterial têm vindo a aumentar junto dos, assim chamados,
jovens adultos. Esta é uma nova realidade com a qual o sector da saúde necessita de
lidar, especialmente o sector público. Apresentados estes cenários, a importância de
encontrar novas formas, mais eficazes ao nível dos custos, de providenciar cuidados
de saúde, a quem deles necessita, torna‐se ainda mais premente, especialmente
quando acreditamos que estes não devem ser deslocalizados do seu “habitat”
natural. Seguindo esta linha de raciocínio, vamos apresentar o projecto VirtualECare,
bem como similares que o precederam. Recentemente tem‐se vindo a assistir a um
interesse crescente em combinar os avanços na, assim chamada, sociedade da
informação – computação, telecomunicações e apresentação – de forma a se criarem
Sistemas de Apoio à Decisão em Grupo (GDSS). Na realidade, a nova economia,
associada ao elevado crescimento da competitividade do, já de si, complexo mundo
empresarial, provoca a procura, por parte das empresas e/ou instituições, de outras
que as possam complementar para assim se poderem tornar mais competitivas e
reduzir os riscos assumidos. Neste cenário, o planeamento assume um papel da
maior importância na vida de uma empresa. No entanto, um planeamento eficaz
depende da geração e posterior análise de ideias (inovativas ou não) e, como
resultado, o processo de geração e análise de ideias também se torna crucial. O nosso objectivo é aplicar os já apresentados GDSS a uma nova área. É de esperar que o uso
de GDSS na área da prestação de cuidados de saúde irá permitir que os seus
profissionais obtenham melhores e mais imediatos resultados na análise de um
qualquer Processo Clínico Electrónico (ECP), sendo este um factor crucial, tendo em
conta a explosão de conhecimento e técnicas conjugadas com a necessidade de
melhor se utilizar os recursos existentes
An Application of Con-Resistant Trust to Improve the Reliability of Special Protection Systems within the Smart Grid
This thesis explores an application of a con-resistant trust mechanism to improve the performance of communications-based special protection systems to further enhance their effectiveness and resiliency. New initiatives in the energy sector are paving the way for the emergent communications-based smart grid technology. Smart grids incorporate modern technologies in an effort to be more reliable and efficient. However, with the benefits of this new technology comes added risk. This research utilizes a con-resistant trust mechanism as a method to quickly identify malicious or malfunctioning protection system nodes in order to mitigate the resulting instabilities in the smart grid. The feasibility and performance of this trust architecture is demonstrated through experiments comparing a simulated special protection system implemented with a con-resistant trust mechanism and without via an analysis of variance statistical model. The simulations yield positive results when implementing the con-resistant trust mechanism within the communications-based special protection system for the smart grid
Privacy-preserving human mobility and activity modelling
The exponential proliferation of digital trends and worldwide responses to the COVID-19 pandemic thrust the world into digitalization and interconnectedness, pushing increasingly new technologies/devices/applications into the market. More and more intimate data of users are collected for positive analysis purposes of improving living well-being but shared with/without the user's consent, emphasizing the importance of making human mobility and activity models inclusive, private, and fair. In this thesis, I develop and implement advanced methods/algorithms to model human mobility and activity in terms of temporal-context dynamics, multi-occupancy impacts, privacy protection, and fair analysis.
The following research questions have been thoroughly investigated: i) whether the temporal information integrated into the deep learning networks can improve the prediction accuracy in both predicting the next activity and its timing; ii) how is the trade-off between cost and performance when optimizing the sensor network for multiple-occupancy smart homes; iii) whether the malicious purposes such as user re-identification in human mobility modelling could be mitigated by adversarial learning; iv) whether the fairness implications of mobility models and whether privacy-preserving techniques perform equally for different groups of users.
To answer these research questions, I develop different architectures to model human activity and mobility. I first clarify the temporal-context dynamics in human activity modelling and achieve better prediction accuracy by appropriately using the temporal information. I then design a framework MoSen to simulate the interaction dynamics among residents and intelligent environments and generate an effective sensor network strategy. To relieve users' privacy concerns, I design Mo-PAE and show that the privacy of mobility traces attains decent protection at the marginal utility cost. Last but not least, I investigate the relations between fairness and privacy and conclude that while the privacy-aware model guarantees group fairness, it violates the individual fairness criteria.Open Acces
Interorganizational Information Systems: Systematic Literature Mapping Protocol
Organizations increasingly need to establish partnerships with other organizations to face environment changes and remain competitive. This interorganizational relationship allows organizations to share resources and collaborate to handle business opportunities better. This technical report present the protocol of the systematic mapping performed to understand what is an IOIS and how these systems support interorganizational relationships
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