An Efficient User-Level Shared Memory Mechanism for Application-Specific Extensions

This paper focuses on an efficient user-level method for the deployment of application-specific extensions, using commodity operating systems and hardware. A sandboxing technique is described that supports multiple extensions within a shared virtual address space. Applications can register sandboxed code with the system, so that it may be executed in the context of any process. Such code may be used to implement generic routines and handlers for a class of applications, or system service extensions that complement the functionality of the core kernel. Using our approach, application-specific extensions can be written like conventional user-level code, utilizing libraries and system calls, with the advantage that they may be executed without the traditional costs of scheduling and context-switching between process-level protection domains. No special hardware support such as segmentation or tagged translation look-aside buffers (TLBs) is required. Instead, our ``user-level sandboxing'' mechanism requires only paged-based virtual memory support, given that sandboxed extensions are either written by a trusted source or are guaranteed to be memory-safe (e.g., using type-safe languages). Using a fast method of upcalls, we show how our mechanism provides significant performance improvements over traditional methods of invoking user-level services. As an application of our approach, we have implemented a user-level network subsystem that avoids data copying via the kernel and, in many cases, yields far greater network throughput than kernel-level approaches.

MyRoom: A user-centred model of affective responsive architecture

Can my immediate physical environment affect how I feel? The instinctive answer to this question must be a resounding “yes”. What might seem a throwaway remark is increasingly borne out by research in environmental and behavioural psychology, and in the more recent discipline of Evidence-Based Design. Research outcomes are beginning to converge with findings in neuroscience and neurophysiology, as we discover more about how the human brain and body functions, and reacts to environmental stimuli. What we see, hear, touch, and sense affects each of us psychologically and, by extension, physically, on a continual basis. The physical characteristics of our daily environment thus have the capacity to profoundly affect all aspects of our functioning, from biological systems to cognitive ability. This has long been understood on an intuitive basis, and utilised on a more conscious basis by architects and other designers. Recent research in evidence-based design, coupled with advances in neurophysiology, confirm what have been previously held as commonalities, but also illuminate an almost frightening potential to do enormous good, or alternatively, terrible harm, by virtue of how we make our everyday surroundings. The thesis adopts a design methodology in its approach to exploring the potential use of wireless sensor networks in environments for elderly people. Vitruvian principles of “commodity, firmness and delight” inform the research process and become embedded in the final design proposals and research conclusions. The issue of person-environment fit becomes a key principle in describing a model of continuously-evolving responsive architecture which makes the individual user its focus, with the intention of promoting wellbeing. The key research questions are: What are the key system characteristics of an adaptive therapeutic single-room environment? How can embedded technologies be utilised to maximise the adaptive and therapeutic aspects of the personal life-space of an elderly person with dementia?.

Becoming a father of a child with an intellectual disability- a narrative inquiry of Irish fathers’ stories

Background: This thesis explored men’s experiences of becoming a father of a child with an intellectual disability in the early years. In Ireland, it is estimated that there are almost 97% (n= 9,914) children with intellectual disabilities living at home in the care of parents, siblings, relatives or foster parents. While mothers and fathers are the primary caregivers, mothers’ experiences are well documented in comparison to the dearth of reports on fathers’ experiences. This descriptive narrative study aims to redress this gap in knowledge and understanding of men’s experiences of becoming a father of a child with an intellectual disability in the early years. Method: Narrative inquiry was employed for this study as it allows stories told by fathers to be collected as a means of exploring men’s transition to becoming a father of a child with an intellectual disability. A sample of 10 fathers of children with intellectual disabilities aged between thirteen months and five years of age were recruited from a large intellectual disability Health Service Provider (HSP) in the South of Ireland. Data were collected through semi-structured interviews which were audio-recorded, transcribed, and analysed using a narrative thematic approach. Findings: Findings are presented in four themes: i) ‘becoming a father’, ii) ‘something wrong with my child’, iii) ‘entering the world of disability’ and iv) ‘living a different life’. For all 10 fathers the time of being told that their child had an intellectual disability was laden with negative emotional responses irrespective of whether the diagnosis was at birth or more gradual over the child’s early developmental period. When fathers found out that ‘something was wrong’ they spoke of ‘moving on’ and entering the world of disability. In their narratives, becoming the father of a child with an intellectual disability had changed their lives and would inevitably change their futures. Fathers’ positivity was clearly evident with many fathers identifying that the diagnosis of their child with an intellectual disability was not a life ending event but rather a life changing event. Conclusions: Healthcare professionals have a critical role in supporting fathers during the transition to becoming a father of a child with an intellectual disability. Factors which require consideration include recognising that each father’s experience is unique; that fathers require support; and that fathers achieve personal growth because of their experiences of their transition to becoming a father of a child with an intellectual disability in the early years.

Politics, Power, PISA: a genealogy of mathematics education policy at second level in Ireland at the beginning of the 21st century

This thesis traces a genealogy of the discourse of mathematics education reform in Ireland at the beginning of the twenty first century at a time when the hegemonic political discourse is that of neoliberalism. It draws on the work of Michel Foucault to identify the network of power relations involved in the development of a single case of curriculum reform – in this case Project Maths. It identifies the construction of an apparatus within the fields of politics, economics and education, the elements of which include institutions like the OECD and the Government, the bureaucracy, expert groups and special interest groups, the media, the school, the State, state assessment and international assessment. Five major themes in educational reform emerge from the analysis: the arrival of neoliberal governance in Ireland; the triumph of human capital theory as the hegemonic educational philosophy here; the dominant role of OECD/PISA and its values in the mathematics education discourse in Ireland; the fetishisation of western scientific knowledge and knowledge as commodity; and the formation of a new kind of subjectivity, namely the subjectivity of the young person as a form of human-capital-to-be. In particular, it provides a critical analysis of the influence of OECD/PISA on the development of mathematics education policy here – especially on Project Maths curriculum, assessment and pedagogy. It unpacks the arguments in favour of curriculum change and lays bare their ideological foundations. This discourse contextualises educational change as occurring within a rapidly changing economic environment where the concept of the State’s economic aspirations and developments in science, technology and communications are reshaping both the focus of business and the demands being put on education. Within this discourse, education is to be repurposed and its consequences measured against the paradigm of the Knowledge Economy – usually characterised as the inevitable or necessary future of a carefully defined present.

A new proposition on the martingale representation theorem and on the approximate hedging of contingent claim in mean-variance criterion

In this work we revisit the problem of the hedging of contingent claim using mean-square criterion. We prove that in incomplete market, some probability measure can be identified so that becomes -martingale under .This is in fact a new proposition on the martingale representation theorem. The new results also identify a weight function that serves to be an approximation to the Radon-Nikodým derivative of the unique neutral martingale measure.

Usages étudiants des outils informatiques liés à Smiley EE

Ce projet de recherche s’inscrit dans un contexte institutionnel particulier. Depuis 2011, l’ULB rénove ses différentes plateformes informatiques afin d’améliorer les outils et services rendus à la communauté étudiante. Portant le nom de « SMILEY », ce grand projet gère entre autres les outils MonULB, GeHol, Web mail, U.V. etc. et a pour objectif une gestion plus simple, plus efficace et plus flexible de l’Université. Étant donné la complexité initiale du système de gestion de l’ULB, la mise en place du projet Smiley ne s’est pas faite sans difficultés. Divers bugs et imprévus ont été et sont encore rencontrés. Dans ce cadre, les autorités de l’ULB ont décidé de créer un observatoire pour mener des recherches sur les usages étudiants des outils informatiques liés à SMILEY EE (pour Études et Étudiants) afin d’améliorer l’acceptation des outils concernés. Au cours de ces recherches, différentes variables en lien avec l’utilisabilité et l’expérience utilisateur seront envisagées :connaissance du web, connaissance des TIC, sentiment d’efficacité personnel, perception de l’utilité et de la facilité d’utilisation des interfaces, stratégies de recherche d’information utilisées, sentiment d’autonomie t de contrôle, satisfaction cognitive et affective, identification à l’institution… Dès lors, les objectifs sont ;outre l’étude des déterminants de l’acceptation des Tic étudiants, de collecter l’avis des utilisateurs concernés, de fournir des recommandations, d’accompagner la mise en œuvre des améliorations et d’anticiper les besoins/attentes futures en matière de TIC à l’université.Pour cela, les méthodologies employées seront qualitatives et quantitatives. Des groupes de discussions exploratoire seront organisés afin d’identifier plus précisément les facteurs de satisfaction et d’insatisfaction, et des tests d’utilisabilités seront élaborés pour déterminer in situ les difficultés rencontrées. Des questionnaires en ligne seront aussi diffusés afin de déterminer le rôle des variables susmentionnées auprès d’un échantillon représentatif de la communauté estudiantine. L’ensemble des résultats permettra alors de guider des actions concrètes sur les outils étudiés.

Gold mining in the Peruvian Amazon: global prices, deforestation, and mercury imports.

Many factors such as poverty, ineffective institutions and environmental regulations may prevent developing countries from managing how natural resources are extracted to meet a strong market demand. Extraction for some resources has reached such proportions that evidence is measurable from space. We present recent evidence of the global demand for a single commodity and the ecosystem destruction resulting from commodity extraction, recorded by satellites for one of the most biodiverse areas of the world. We find that since 2003, recent mining deforestation in Madre de Dios, Peru is increasing nonlinearly alongside a constant annual rate of increase in international gold price (∼18%/yr). We detect that the new pattern of mining deforestation (1915 ha/year, 2006-2009) is outpacing that of nearby settlement deforestation. We show that gold price is linked with exponential increases in Peruvian national mercury imports over time (R(2) = 0.93, p = 0.04, 2003-2009). Given the past rates of increase we predict that mercury imports may more than double for 2011 (∼500 t/year). Virtually all of Peru's mercury imports are used in artisanal gold mining. Much of the mining increase is unregulated/artisanal in nature, lacking environmental impact analysis or miner education. As a result, large quantities of mercury are being released into the atmosphere, sediments and waterways. Other developing countries endowed with gold deposits are likely experiencing similar environmental destruction in response to recent record high gold prices. The increasing availability of satellite imagery ought to evoke further studies linking economic variables with land use and cover changes on the ground.