9 research outputs found

    Projection based ensemble learning for ordinal regression

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    The classification of patterns into naturally ordered labels is referred to as ordinal regression. This paper proposes an ensemble methodology specifically adapted to this type of problems, which is based on computing different classification tasks through the formulation of different order hypotheses. Every single model is trained in order to distinguish between one given class (k) and all the remaining ones, but grouping them in those classes with a rank lower than k, and those with a rank higher than k. Therefore, it can be considered as a reformulation of the well-known one-versus-all scheme. The base algorithm for the ensemble could be any threshold (or even probabilistic) method, such as the ones selected in this paper: kernel discriminant analysis, support vector machines and logistic regression (all reformulated to deal with ordinal regression problems). The method is seen to be competitive when compared with other state-of-the-art methodologies (both ordinal and nominal), by using six measures and a total of fifteen ordinal datasets. Furthermore, an additional set of experiments is used to study the potential scalability and interpretability of the proposed method when using logistic regression as base methodology for the ensemble

    Proceedings Scholar Metrics: H Index of proceedings on Computer Science, Electrical & Electronic Engineering, and Communications according to Google Scholar Metrics (2011-2015)

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    The objective of this report is to present a list of proceedings (conferences, workshops, symposia, meetings) in the areas of Computer Science, Electrical & Electronic Engineering, and Communications covered by Google Scholar Metrics and ranked according to their h-index. Google Scholar Metrics only displays publications that have published at least 100 papers and have received at least one citation in the last five years (2010-2014). The searches were conducted between the 7th and 12th of December, 2016. A total of 1634 proceedings have been identified.Martín-Martín, A.; Ayllón, JM.; Orduña Malea, E.; Delgado López-Cózar, E. (2016). Proceedings Scholar Metrics: H Index of proceedings on Computer Science, Electrical & Electronic Engineering, and Communications according to Google Scholar Metrics (2011-2015). http://hdl.handle.net/10251/11237

    Proceedings Scholar Metrics: H Index of proceedings on Computer Science, Electrical & Electronic Engineering, and Communications according to Google Scholar Metrics (2011-2015)

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    1st edition, Published Granada 13 December 2016The objective of this report is to present a list of proceedings (conferences, workshops, symposia, meetings) in the areas of Computer Science, Electrical & Electronic Engineering, and Communications covered by Google Scholar Metrics and ranked according to their h-index. Google Scholar Metrics only displays publications that have published at least 100 papers and have received at least one citation in the last five years (2011-2015). The searches were conducted between the 7th and 12th of December, 2016. A total of 1634 proceedings have been identified.Juan Manuel Ayllón has a FPI pre-doctoral scholarship for research (BES-2012-054980) funded by the Spanish Ministry of Economy and Competitiveness. Alberto Martín-Martín holds a fellowship for the training of university teachers (FPU2013/05863), funded by the Spanish Ministry of Education, Culture and Spor

    mFerio: The design and evaluation of a peer-to-peer mobile payment system

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    Ministry of Education, Singapore under its Academic Research Funding Tier

    A framework for decentralised trust reasoning.

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    Recent developments in the pervasiveness and mobility of computer systems in open computer networks have invalidated traditional assumptions about trust in computer communications security. In a fundamentally decentralised and open network such as the Internet, the responsibility for answering the question of whether one can trust another entity on the network now lies with the individual agent, and not a priori a decision to be governed by a central authority. Online agents represent users' digital identities. Thus, we believe that it is reasonable to explore social models of trust for secure agent communication. The thesis of this work is that it is feasible to design and formalise a dynamic model of trust for secure communications based on the properties of social trust. In showing this, we divide this work into two phases. The aim of the first is to understand the properties and dynamics of social trust and its role in computer systems. To this end, a thorough review of trust, and its supporting concept, reputation, in the social sciences was carried out. We followed this by a rigorous analysis of current trust models, comparing their properties with those of social trust. We found that current models were designed in an ad-hoc basis, with regards to trust properties. The aim of the second phase is to build a framework for trust reasoning in distributed systems. Knowledge from the previous phase is used to design and formally specify, in Z, a computational trust model. A simple model for the communication of recommendations, the recommendation protocol, is also outlined to complement the model. Finally an analysis of possible threats to the model is carried out. Elements of this work have been incorporated into Sun's JXTA framework and Ericsson Research's prototype trust model

    Model checking security protocols : a multiagent system approach

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    Security protocols specify the communication required to achieve security objectives, e.g., data-privacy. Such protocols are used in electronic media: e-commerce, e-banking, e-voting, etc. Formal verification is used to discover protocol-design flaws. In this thesis, we use a multiagent systems approach built on temporal-epistemic logic to model and analyse a bounded number of concurrent sessions of authentication and key-establishment protocols executing in a Dolev-Yao environment. We increase the expressiveness of classical, trace-based frameworks by mapping each protocol requirement into a hierarchy of temporal-epistemic formulae. To automate our methodology, we design and implement a tool called PD2IS. From a high-level protocol description, PD2IS produces our protocol model and the temporal-epistemic specifications of the protocol’s goals. This output is verified with the model checker MCMAS. We benchmark our methodology on various protocols drawn from standard repositories. We extend our approach to formalise protocols described by equations of cryptographic primitives. The core of this extension is an indistinguishability relation to accommodate the underlying protocol equations. Based on this relation, we introduce a knowledge modality and an algorithm to model check multiagent systems against it. These techniques are applied to verify e-voting protocols. Furthermore, we develop our methodology towards intrusion-detection techniques. We introduce the concept of detectability, i.e., the ability of protocol participants to detect jointly that the protocol is being attacked. We extend our formalisms and PD2IS to support detectability analysis. We model check several attack-prone protocols against their detectability specifications

    Model Checking Security Protocols: A Multiagent System Approach

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    Security protocols specify the communication required to achieve security objectives, e.g., data-privacy. Such protocols are used in electronic media: e-commerce, e-banking, e-voting, etc. Formal verification is used to discover protocol-design flaws. In this thesis, we use a multiagent systems approach built on temporal-epistemic logic to model and analyse a bounded number of concurrent sessions of authentication and key-establishment protocols executing in a Dolev-Yao environment. We increase the expressiveness of classical, trace-based frameworks by mapping each protocol requirement into a hierarchy of temporal-epistemic formulae. To automate our methodology, we design and implement a tool called PD2IS. From a high-level protocol description, PD2IS produces our protocol model and the temporal-epistemic specifications of the protocol’s goals. This output is verified with the model checker MCMAS. We benchmark our methodology on various protocols drawn from standard repositories. We extend our approach to formalise protocols described by equations of cryptographic primitives. The core of this extension is an indistinguishability relation to accommodate the underlying protocol equations. Based on this relation, we introduce a knowledge modality and an algorithm to model check multiagent systems against it. These techniques are applied to verify e-voting protocols. Furthermore, we develop our methodology towards intrusion-detection techniques. We introduce the concept of detectability, i.e., the ability of protocol participants to detect jointly that the protocol is being attacked. We extend our formalisms and PD2IS to support detectability analysis. We model check several attack-prone protocols against their detectability specifications

    Eight Biennial Report : April 2005 – March 2007

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