A dual-band antenna enabling improved quality of service in multi-radio wireless sensor applications in indoor environments

Science Foundation Ireland (CSET - Centre for Science, Engineering and Technology, Grant No. 07/CE/11147)

The differences in the social competence of children who attend integrated junior infant classes and children who attend segregated learning environments

There are a number of reasons why this researcher has decided to undertake this study into the differences in the social competence of children who attend integrated Junior Infant classes and children who attend segregated learning environments. Theses reasons are both personal and professional. My personal reasons stem from having grown up in a family which included both an aunt who presented with Down Syndrome and an uncle who presented with hearing impairment. Both of these relatives' experiences in our education system are interesting. My aunt was considered ineducable while her brother - my uncle - was sent to Dublin (from Cork) at six years of age to be educated by a religious order. My professional reasons, on the other hand, stemmed from my teaching experience. Having taught in both special and integrated classrooms it became evident to me that there was somewhat 'suspicion' attached to integration. Parents of children without disabilities questioned whether this process would have a negative impact on their children's education. While parents of children with disabilities debated whether integrated settings met the specific needs of their children. On the other hand, I always questioned whether integration and inclusiveness meant the same thing. My research has enabled me to find many answers. Increasingly, children with special educational needs (SEN) are attending a variety of integrated and inclusive childcare and education settings. This contemporary practice of educating children who present with disabilities in mainstream classrooms has stimulated vast interest on the impact of such practices on children with identified disabilities. Indeed, children who present with disabilities "fare far better in mainstream education than in special schools" (Buckley, cited in Siggins, 2001,p.25). However, educators and practitioners in the field of early years education and care are concerned with meeting the needs of all children in their learning environments, while also upholding high academic standards (Putman, 1993). Fundamentally, therefore, integrated education must also produce questions about the impact of this practice on children without identified special educational needs. While these questions can be addressed from the various areas of child development (i.e. cognitive, physical, linguistic, emotional, moral, spiritual and creative), this research focused on the social domain. It investigates the development of social competence in junior infant class children without identified disabilities as they experience different educational settings.

Molecular characterisation of the mechanisms of compatible solute accumulation in Listeria monocytogenes

The ability of the Gram-positive foodborne pathogen Listeria monocytogenes to survive and grow in environments of elevated osmolarity can be attributed, at least in part, to the accumulation of a restricted range of low molecular mass solutes compatible with cellular function. Accumulated to high internal concentrations in hyper-saline environments, compatible solutes, either transported into the cell or synthesized de novo, play a dual role: helping to stabilize protein structure and function while also counterbalancing external osmotic strength, thus preventing water loss from the cell and plasmolysis. While previous physiological investigations identified glycine betaine, carnitine, and proline as the principal compatible solutes in the listerial osmostress response, genetic alanysis of the uptake/synthesis systems governing the accumulation of these compounds has, until now, remained largely unexplored. Representing the first genetic analysis of compatible solute accumulation in L. monocytogenes, this thesis describes the molecular characterization of BetL; a highly specific secondary glycine betaine transport system, OpuC; a multicomponent carnitine/glycine betaine transporter, and finally proBA; a two-gene operon encoding the first two enzymes of the listerial proline piosynthesis pathway. In addition to their role in osmotolerance, the potential of each system in contributing to listerial pathogenesis was investigated. While mutations in each gene cluster exhibited dramatic reductions in listerial osmotolerance, OpuC- mutants were additionally shown to exhibit reduced virulence when admisistered via the oral route. This represents the first direct link between the salt stress response and virulence in L. monocytogenes.

The brand-orientated play-community: toxic play in the marketplace

This ethnographic study makes a number of original contributions to the consumer identity projects and the marketplace cultures dimensions of consumer culture theory research. This study introduces the notion of the brand-orientated play-community, a novel consumption community form, which displays, as locus, a desire to play. This contributes to our understanding of the fluid relationship between subcultures of consumption, consumer tribes, and brand community. It was found that the brand-orientated play-community’s prime celebration, conceptualised as the ‘branded carnival’, displays characteristics of the archetypal carnival. The community access carnivalistic life and a world-upside-down ethos via the use and misuse of marketplace resources. The branded carnival is further supported by the community’s enactment of ‘toxic play’, which entails abnormal alcohol consumption, black market illegal resources, edgework activities, hegemonic masculinity and upsetting the public. This play-community is discussed in terms of a hyper-masculine playpen, as the play enacted has a direct relationship with the enactment of strong masculine roles. It was found that male play-ground members enact the extremes of contrasting masculine roles as a means to subvert the calculated and sedate ‘man-of-action-hero’ synthesis. Carnivals are unisex, and hence, women have begun entering the play-ground. Female members have successfully renegotiated their role within the community, from playthings to players – they have achieved player equality, which within the liminoid zone is more powerful than gender equality. However, while toxic play is essential to the maintenance of collective identity within the culture so too is the more serious form of play: the toxic sport of professional beer pong. The author conceptualises beer pong as a ‘toxic sport’, as it displays the contradictory play foundations of agon and corrupt ilinx: this is understood as a milestone step in the emergence of the postmodern sport era, in which spontaneity and the carnivalesque will dominate.

Repairing wireless sensor network connectivity in damaged environments

A wireless sensor network can become partitioned due to node failure, requiring the deployment of additional relay nodes in order to restore network connectivity. This introduces an optimisation problem involving a tradeoff between the number of additional nodes that are required and the costs of moving through the sensor field for the purpose of node placement. This tradeoff is application-dependent, influenced for example by the relative urgency of network restoration. In addition, minimising the number of relay nodes might lead to long routing paths to the sink, which may cause problems of data latency. This data latency is extremely important in wireless sensor network applications such as battlefield surveillance, intrusion detection, disaster rescue, highway traffic coordination, etc. where they must not violate the real-time constraints. Therefore, we also consider the problem of deploying multiple sinks in order to improve the network performance. Previous research has only parts of this problem in isolation, and has not properly considered the problems of moving through a constrained environment or discovering changes to that environment during the repair or network quality after the restoration. In this thesis, we firstly consider a base problem in which we assume the exploration tasks have already been completed, and so our aim is to optimise our use of resources in the static fully observed problem. In the real world, we would not know the radio and physical environments after damage, and this creates a dynamic problem where damage must be discovered. Therefore, we extend to the dynamic problem in which the network repair problem considers both exploration and restoration. We then add a hop-count constraint for network quality in which the desired locations can talk to a sink within a hop count limit after the network is restored. For each new problem of the network repair, we have proposed different solutions (heuristics and/or complete algorithms) which prioritise different objectives. We evaluate our solutions based on simulation, assessing the quality of solutions (node cost, movement cost, computation time, and total restoration time) by varying the problem types and the capability of the agent that makes the repair. We show that the relative importance of the objectives influences the choice of algorithm, and different speeds of movement for the repairing agent have a significant impact on performance, and must be taken into account when selecting the algorithm. In particular, the node-based approaches are the best in the node cost, and the path-based approaches are the best in the mobility cost. For the total restoration time, the node-based approaches are the best with a fast moving agent while the path-based approaches are the best with a slow moving agent. For a medium speed moving agent, the total restoration time of the node-based approaches and that of the path-based approaches are almost balanced.

Dairy-Met: compositional metagenomic analysis of milk and cheeses

Unpasteurised milk and many cheeses contain a diverse microbiological population. These microorganisms play important roles in dairy foods and can, for example, contribute to the development of flavours and aromas, determine safety, cause spoilage or enhance the health of the consumer. It is thus important to understand thoroughly the microorganisms present in these food types. Traditional culture dependent and culture-independent methods have provided much detail regarding the microbial content of dairy foods. However, the development of next-generation DNA sequencing technologies has revolutionised our knowledge of complex microbial environments. Throughout this thesis we observe the benefits of applying these technologies to provide a detailed understanding of the bacterial content of dairy foods, including those present in milk pre- and post-pasteurisation, Irish farmhouse cheeses and commercially produced cheeses which encounter a discolouration defect, as well as to study genomic changes in microbes associated with dairy foods. Through the application of these state-of-the-art technologies we identified the presence of microorganisms not previously associated with dairy foods.

Real time analysis of atmospheric single particles in urban environments using aerosol time of flight mass spectrometry

In order to determine the size-resolved chemical composition of single particles in real-time an ATOFMS was deployed at urban background sites in Paris and Barcelona during the MEGAPOLI and SAPUSS monitoring campaigns respectively. The particle types detected during MEGAPOLI included several carbonaceous species, metal-containing types and sea-salt. Elemental carbon particle types were highly abundant, with 86% due to fossil fuel combustion and 14% attributed to biomass burning. Furthermore, 79% of the EC was apportioned to local emissions and 21% to continental transport. The carbonaceous particle types were compared with quantitative measurements from other instruments, and while direct correlations using particle counts were poor, scaling of the ATOFMS counts greatly improved the relationship. During SAPUSS carbonaceous species, sea-salt, dust, vegetative debris and various metal-containing particle types were identified. Throughout the campaign the site was influenced by air masses altering the composition of particles detected. During North African air masses the city was heavily influenced by Saharan dust. A regional stagnation was also observed leading to a large increase in carbonaceous particle counts. While the ATOFMS provides a list of particle types present during the measurement campaigns, the data presented is not directly quantitative. The quantitative response of the ATOFMS to metals was examined by comparing the ion signals within particle mass spectra and to hourly mass concentrations of; Na, K, Ca, Ti, V, Cr, Mn, Fe, Zn and Pb. The ATOFMS was found to have varying correlations with these metals depending on sampling issues such as matrix effects. The strongest correlations were observed for Al, Fe, Zn, Mn and Pb. Overall the results of this work highlight the excellent ability of the ATOFMS in providing composition and mixing state information on atmospheric particles at high time resolution. However they also show its limitations in delivering quantitative information directly.

States of play: Irish childhoods, race and belonging

This thesis explores the meaning-making practices of migrant and non-migrant children in relation to identities, race, belonging and childhood itself in their everyday lives and in the context of ‘normalizing’ discourses and spaces in Ireland. The relational, spatial and institutional contexts of children’s worlds are examined in the arenas of school, home, family, peer groups and consumer culture. The research develops a situated account of children’s complex subject positions, belongings and exclusions, as negotiated within discursive constructs, emerging in the ‘in-between’ spaces explored with other children and with adults. As a peripheral EU area both geographically and economically, Ireland has traditionally been a country of net emigration. This situation changed briefly in the late 1990s to early 2000s, sparking broad debate on Ireland’s perceived ‘new’ ethnic, cultural and linguistic diversity arising from the arrival of migrant people both from within and beyond the EU as workers and as asylum seekers, and drawing attention to issues of race, identity, equality and integration in Irish society. Based in a West of Ireland town where migrant children and children of migrants comprise very small minorities in classroom settings, this research engages with a particular demographic of children who have started primary school since these changes have occurred. It seeks to represent the complexities of the processes which constitute children’s subjectivities, and which also produce and reproduce race and childhood itself in this context. The role of local, national and global spaces, relational networks and discursive currents as they are experienced and negotiated by children are explored, and the significance of embodied, sensory and affective processes are integrated into the analysis. Notions of the functions and rhetorics of play and playfulness (Sutton-Smith 1997) form a central thread that runs throughout the thesis, where play is both a feature of children’s cultural worlds and a site of resistance or ‘thinking otherwise’. The study seeks to examine how children actively participate in (re)producing definitions of both childhood and race arising in local, national and global spaces, demonstrating that while contestations of the boundaries of childhood discourses are contingently successful, race tends to be strongly reiterated, clinging to bodies and places and compromising belonging. In addition, it explores how children access belongings through agentic and imaginative practices with regard to peer and family relationships, particularly highlighting constructions of home, while also illustrating practices of excluding children positioned as unintelligible, including the role of silences in such situations. Finally, drawing on teachers’ understandings and on children’s playful micro-level negotiations of race, the study argues that assumptions of childhood innocence contribute to justifying depoliticised discourses of race in the early primary school years, and also tend to silence children’s own dialogues with this issue. Central throughout the thesis is an emphasis on the productive potentials of children’s marginal positioning in processes of transgressing definitional boundaries, including the generation of post-race conceptualisations that revealed the borders of race as performative and fluid. It suggests that interrupting exclusionary raced identities in Irish primary schools requires engagement with children’s world-making practices and the multiple resources that inform their lives.

Subterfuge-safe trust management for delegation of permissions in open environments

Open environments involve distributed entities interacting with each other in an open manner. Many distributed entities are unknown to each other but need to collaborate and share resources in a secure fashion. Usually resource owners alone decide who is trusted to access their resources. Since resource owners in open environments do not have a complete picture of all trusted entities, trust management frameworks are used to ensure that only authorized entities will access requested resources. Every trust management system has limitations, and the limitations can be exploited by malicious entities. One vulnerability is due to the lack of globally unique interpretation for permission specifications. This limitation means that a malicious entity which receives a permission in one domain may misuse the permission in another domain via some deceptive but apparently authorized route; this malicious behaviour is called subterfuge. This thesis develops a secure approach, Subterfuge Safe Trust Management (SSTM), that prevents subterfuge by malicious entities. SSTM employs the Subterfuge Safe Authorization Language (SSAL) which uses the idea of a local permission with a globally unique interpretation (localPermission) to resolve the misinterpretation of permissions. We model and implement SSAL with an ontology-based approach, SSALO, which provides a generic representation for knowledge related to the SSAL-based security policy. SSALO enables integration of heterogeneous security policies which is useful for secure cooperation among principals in open environments where each principal may have a different security policy with different implementation. The other advantage of an ontology-based approach is the Open World Assumption, whereby reasoning over an existing security policy is easily extended to include further security policies that might be discovered in an open distributed environment. We add two extra SSAL rules to support dynamic coalition formation and secure cooperation among coalitions. Secure federation of cloud computing platforms and secure federation of XMPP servers are presented as case studies of SSTM. The results show that SSTM provides robust accountability for the use of permissions in federation. It is also shown that SSAL is a suitable policy language to express the subterfuge-safe policy statements due to its well-defined semantics, ease of use, and integrability.