Martin J.S.,Technical University of Madrid |
Martin J.S.,Spanish University for Distance Education (UNED) |
O'Farrell A.G.,NUI Maynooth Co.
International Journal of Adaptive Control and Signal Processing | Year: 2013
We report conditions on a switching signal that guarantee that solutions of a switched linear system converge asymptotically to zero. These conditions apply to continuous, discrete-time and hybrid switched linear systems, those having both stable subsystems and mixtures of stable and unstable subsystems. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.
Batty M.,University College London |
Axhausen K.W.,ETH Zurich |
Giannotti F.,University of Pisa |
Pozdnoukhov A.,NUI Maynooth Co. |
And 4 more authors.
European Physical Journal: Special Topics | Year: 2012
Here we sketch the rudiments of what constitutes a smart city which we define as a city in which ICT is merged with traditional infrastructures, coordinated and integrated using new digital technologies. We first sketch our vision defining seven goals which concern: developing a new understanding of urban problems; effective and feasible ways to coordinate urban technologies; models and methods for using urban data across spatial and temporal scales; developing new technologies for communication and dissemination; developing new forms of urban governance and organisation; defining critical problems relating to cities, transport, and energy; and identifying risk, uncertainty, and hazards in the smart city. To this, we add six research challenges: to relate the infrastructure of smart cities to their operational functioning and planning through management, control and optimisation; to explore the notion of the city as a laboratory for innovation; to provide portfolios of urban simulation which inform future designs; to develop technologies that ensure equity, fairness and realise a better quality of city life; to develop technologies that ensure informed participation and create shared knowledge for democratic city governance; and to ensure greater and more effective mobility and access to opportunities for urban populations.We begin by defining the state of the art, explaining the science of smart cities. We define six scenarios based on new cities badging themselves as smart, older cities regenerating themselves as smart, the development of science parks, tech cities, and technopoles focused on high technologies, the development of urban services using contemporary ICT, the use of ICT to develop new urban intelligence functions, and the development of online and mobile forms of participation. Seven project areas are then proposed: Integrated Databases for the Smart City, Sensing, Networking and the Impact of New Social Media, Modelling Network Performance, Mobility and Travel Behaviour, Modelling Urban Land Use, Transport and Economic Interactions, Modelling Urban Transactional Activities in Labour and Housing Markets, Decision Support as Urban Intelligence, Participatory Governance and Planning Structures for the Smart City. Finally we anticipate the paradigm shifts that will occur in this research and define a series of key demonstrators which we believe are important to progressing a science of smart cities.© The Author(s) 2012.
Nogueira Da Costa A.,University of Leeds |
Nogueira Da Costa A.,International Agency for Research on Cancer |
Keen J.N.,University of Leeds |
Wild C.P.,University of Leeds |
And 2 more authors.
Biochimica et Biophysica Acta - Proteins and Proteomics | Year: 2011
The mycotoxin deoxynivalenol (DON) commonly contaminates cereal grains. It is ubiquitous in the Western European diet, although chronic, low-dose effects in humans are not well described, but immunotoxicity has been reported. In this study, two-dimensional gel electrophoresis was used to identify phosphoproteomic changes in human B (RPMI1788) and T (Jurkat E6.1) lymphocyte cell lines after exposure to modest concentrations of DON (up to 500 ng/mL) for 24 h. Proteins identified as having altered phosphorylation state post-treatment (C-1-tetrahydrofolate synthase, eukaryotic elongation factor 2, nucleoside diphosphate kinase A, heat shock cognate 71 kDa protein, eukaryotic translation initiation factor 3 subunit I and growth factor receptor-bound protein 2) are involved in regulation of metabolic pathways, protein biosynthesis and signaling transduction. All exhibited a greater than 1.4-fold change, reproducible in three separate experiments consisting of 36 gels in total. Flow cytometry validated the observations for eukaryotic elongation factor 2 and growth factor receptor-bound protein 2. These findings provide further insights as to how low dose exposure to DON may affect human immune function and may have potential as mechanism-based phosphoprotein biomarkers for DON exposure. © 2011 Elsevier B.V. All rights reserved.
Knorn S.,NUI Maynooth Co. |
Middleton R.H.,University of Newcastle
2012 2nd Australian Control Conference, AUCC 2012 | Year: 2012
String stability issues in vehicle platoons have been studied in various ways. In the homogeneous unidirectional case, the platoon can be considered as a two dimensional (2D) continuous-discrete systems with an unavoidable singularity on the stability boundary and care is needed in their analysis. Frequency domain analysis of such 2D systems allows analysis of BIBO stability and other features. © 2012 Institute of Engineers.
Dutta R.,NUI Maynooth Co. |
Mukhopadhyay S.,Dublin City University |
Dowling T.,NUI Maynooth Co.
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering | Year: 2010
A fundamental concern of any secure group communication system is that of key management. Wireless environments create new key management problems and requirements to solve these problems. One such core requirement in these emerging networks is that of self-healing. In systems where users can be offline and miss updates self healing allows a user to recover lost keys and get back into the secure communication without putting extra burden on the group manager. Clearly self healing must be only available to authorized users and this creates more challenges in that we must ensure unauthorized or revoked users cannot, themselves or by means of collusion, avail of self healing. To this end we enhance the one-way key chain based self-healing key distribution of Dutta et al. by introducing a collusion resistance property between the revoked users and the newly joined users. Our scheme is based on the concept of access polynomials. These can be loosely thought of as white lists of authorized users as opposed to the more widely used revocation polynomials or black lists of revoked users. We also allow each user a pre-arranged life cycle distributed by the group manager. Our scheme provides better efficiency in terms of storage, and the communication and computation costs do not increase as the number of sessions grows as compared to most current schemes. We analyze our scheme in an appropriate security model and prove that the proposed scheme is computationally secure and not only achieving forward and backward secrecy, but also resisting collusion between the new joined users and the revoked users. Unlike most existing schemes the new scheme allows temporary revocation. Also unlike existing schemes, our construction does not collapse if the number of revoked users crosses a threshold value. This feature increases resilience against revocation based denial of service (DOS) attacks and thus improves availability of communication channel. © Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering 2010.
Medioli A.,University of Newcastle |
Seron M.,University of Newcastle |
Middleton R.,NUI Maynooth Co
Automatica | Year: 2011
The null controllable set of a system is the largest set of states that can be controlled to the origin. Control systems that have a region of attraction equal to the null controllable set are said to be maximally controllable closed-loop systems. In the case of open-loop unstable plants with amplitude constrained control it is well known that the null controllable set does not cover the entire state-space. Further the combination of input constraints and unstable system dynamics results in a set of state constraints which we call implicit constraints. It is shown that the simple inclusion of implicit constraints in a controller formulation results in a controller that achieves maximal controllability for a class of open-loop unstable systems. © 2011 Elsevier Ltd. All rights reserved.
Corless M.,Purdue University |
Shorten R.,NUI Maynooth Co.
International Journal of Control | Year: 2012
In this article we propose a version of the Additive-Increase Multiplicative-Decrease (AIMD) algorithm that provides a suitable basis to develop congestion control protocols that can be deployed in both conventional and high-speed communication networks. Our algorithm retains many of the properties of the standard AIMD algorithm. However, unlike other non-standard AIMD algorithms, our scheme can be shown to be ergodic under very general assumptions. © 2012 Taylor & Francis.
Foley A.,NUI Maynooth Co. |
Foley A.,University of Cambridge |
Fealy R.,NUI Maynooth Co. |
Sweeney J.,NUI Maynooth Co.
Climate Research | Year: 2013
In the present study, a range of regional climate models have been used to test approaches to Bayesian model averaging (BMA), particularly the quantification of model weights/Bayesian priors. The results of skill assessments were used to inform probabilistic future projections of Irish climate using a BMA approach in order to evaluate how different approaches to skill assessment, based on representation of climate means, or of a large-scale driver (the NAO), or a combination thereof, may influence the final climate projection. Results indicate that meansbased skill assessments may not always provide a useful indication of model skill and that further analyses are required to assess a model's ability to simulate the dynamics of the climate system. While this research illustrates that the use of metrics derived from the model predicted NAO impacts on the regional projection, it also supports the inclusion of other large-scale model diagnostics. When used to weight model projections to produce ensemble climate projections, the choice of skill metric may have an impact on the shape of the probability distribution and the most probable outcome of future climate predictions. The present study demonstrates that when working with probabilistic outputs of ensemble climate modelling experiments, awareness of the approaches used to evaluate models and the techniques used to combine them to formulate ensemble projections are integral in enabling robust responses to the potential changes in climate represented by models. © 2012 Inter-Research.
Mooney P.,NUI Maynooth Co. |
Corcoran P.,NUI Maynooth Co. |
Winstanley A.C.,NUI Maynooth Co.
GIS: Proceedings of the ACM International Symposium on Advances in Geographic Information Systems | Year: 2010
Volunteered Geographic Information (VGI) is currently a "hot topic" in the GIS community. The OpenStreetMap (OSM) project is one of the most popular and well supported examples of VGI. Traditional measures of spatial data quality are often not applicable to OSM as in many cases it is not possible to access ground-truth spatial data for all regions mapped by OSM. We investigate to develop measures of quality for OSM which operate in an unsupervised manner without reference to a "trusted" source of ground-truth data. We provide results of analysis of OSM data from several European countries. The results highlight specific quality issues in OSM. Results of comparing OSM with ground-truth data for Ireland are also presented. © 2010 ACM.
Leith D.J.,NUI Maynooth Co. |
Subramanian V.G.,NUI Maynooth Co.
2010 48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010 | Year: 2010
In this paper we explore multiple ways of achieving utility-based fairness in wireless mesh networks of 802.11-based devices. We show the log-convexity of the rate-region and use this for achieving utility fair solutions for the family of iso-elastic of utility functions with elasticity lower than 1. We then use this to characterize the max-min fair solution. We then prove convexity of the non-achievable rate-region of a WLAN and use that to achieve utility fairness for utility functions that do not correspond to the special family above. ©2010 IEEE.