915 resultados para Subject headings.
Resumo:
Among the key challenges present in the modelling and optimisation of composite structures against impact is the computational expense involved in setting up accurate simulations of the impact event and then performing the iterations required to optimise the designs. It is of more interest to find good designs given the limitations of the resources and time available rather than the best possible design. In this paper, low cost but sufficiently accurate finite element (FE) models were generated in LS Dyna for several experimentally characterised materials by semi-automating the modelling process and using existing material models. These models were then used by an optimisation algorithm to generate new hybrid offspring, leading to minimum weight and/or cost designs from a selection of isotropic metals, polymers and orthotropic fibre-reinforced laminates that countered a specified impact threat. Experimental validation of the optimal designs thus identified was then successfully carried out using a single stage gas gun. With sufficient computational hardware, the techniques developed in this pilot study can further utilise fine meshes, equations of state and sophisticated material models, so that optimal hybrid systems can be identified from a wide range of materials, designs and threats.
Resumo:
CCTV systems are broadly deployed in the present world. Despite this, the impact on anti-social and criminal behaviour has been minimal. Subject reacquisition is a fundamental task to ensure in-time reaction for intelligent surveillance. However, traditional reacquisition based on face recognition is not scalable, hence in this paper we use reasoning techniques to reduce the computational effort which deploys the time-of-flight information between interested zones such as airport security corridors. Also, to improve accuracy of reacquisition, we introduce the idea of revision as a method of post-processing.We demonstrate the significance and usefulness of our framework with an experiment which shows much less computational effort and better accuracy.
Resumo:
Almost a decade ago, the new subject of citizenship was created in the English National Curriculum and several universities were funded to train teachers in this new subject. This presented a rare challenge, namely how to train people to teach a subject that did not exist in schools, and in which they were unlikely to have a specialist degree. In this article we have taken the opportunity afforded by the
tenth birthday of the report in which Crick recommended this curriculum reform to reflect on that experience from the perspective of teacher educators. Through reflecting on the case study of citizenship education in England we highlight several themes that are of more general interest to teacher educators. The key issues that have emerged in this case study relate to the general problems of translating central policy into classroom practice; the nature and aims of subjects in the curriculum; and the identities of teachers in secondary schools. The article illustrates how teacher educators responded to the formidable challenge of creating (or at least contributing to) a new subject and a subject community.
Resumo:
Abortion is a contentious subject for any nation and this is no less true of Northern Ireland (NI). Despite being part of the United Kingdom, NI has never enacted the Abortion Act 1967 and the reasons given are our historically conservative attitudes and beliefs. In April 2013 the latest in a series of draft guidelines entitled ‘The Limited Circumstances for a Lawful Termination of Pregnancy in Northern Ireland’ was issued by the Department of Health NI to clarify aspects of earlier versions that were revoked following challenges by pro-life groups on their accuracy and application. That draft guidelines exist at all is down to pressure placed on the Department of Health NI by the fpaNI through the NI Courts.
Resumo:
The principle feature in the evolution of the internet has been its ever growing reach to include old and young, rich and poor. The internet’s ever encroaching presence has transported it from our desktop to our pocket and into our glasses. This is illustrated in the Internet Society Questionnaire on Multistakeholder Governance, which found the main factors affecting change in the Internet governance landscape were more users online from more countries and the influence of the internet over daily life. The omnipresence of the internet is self- perpetuating; its usefulness grows with every new user and every new piece of data uploaded. The advent of social media and the creation of a virtual presence for each of us, even when we are not physically present or ‘logged on’, means we are fast approaching the point where we are all connected, to everyone else, all the time. We have moved far beyond the point where governments can claim to represent our views which evolve constantly rather than being measured in electoral cycles.
The shift, which has seen citizens as creators of content rather than consumers of it, has undermined the centralist view of democracy and created an environment of wiki democracy or crowd sourced democracy. This is at the heart of what is generally known as Web 2.0, and widely considered to be a positive, democratising force. However, we argue, there are worrying elements here too. Government does not always deliver on the promise of the networked society as it involves citizens and others in the process of government. Also a number of key internet companies have emerged as powerful intermediaries harnessing the efforts of the many, and re- using and re-selling the products and data of content providers in the Web 2.0 environment. A discourse about openness and transparency has been offered as a democratising rationale but much of this masks an uneven relationship where the value of online activity flows not to the creators of content but to those who own the channels of communication and the metadata that they produce.
In this context the state is just one stakeholder in the mix of influencers and opinion formers impacting on our behaviours, and indeed our ideas of what is public. The question of what it means to create or own something, and how all these new relationships to be ordered and governed are subject to fundamental change. While government can often appear slow, unwieldy and even irrelevant in much of this context, there remains a need for some sort of political control to deal with the challenges that technology creates but cannot by itself control. In order for the internet to continue to evolve successfully both technically and socially it is critical that the multistakeholder nature of internet governance be understood and acknowledged, and perhaps to an extent, re- balanced. Stakeholders can no longer be classified in the broad headings of government, private sector and civil society, and their roles seen as some sort of benign and open co-production. Each user of the internet has a stake in its efficacy and each by their presence and participation is contributing to the experience, positive or negative of other users as well as to the commercial success or otherwise of various online service providers. However stakeholders have neither an equal role nor an equal share. The unequal relationship between the providers of content and those who simple package up and transmit that content - while harvesting the valuable data thus produced - needs to be addressed. Arguably this suggests a role for government that involves it moving beyond simply celebrating and facilitating the on- going technological revolution. This paper reviews the shifting landscape of stakeholders and their contribution to the efficacy of the internet. It will look to critically evaluate the primacy of the individual as the key stakeholder and their supposed developing empowerment within the ever growing sea of data. It also looks at the role of individuals in wider governance roles. Governments in a number of jurisdictions have sought to engage, consult or empower citizens through technology but in general these attempts have had little appeal. Citizens have been too busy engaging, consulting and empowering each other to pay much attention to what their governments are up to. George Orwell’s view of the future has not come to pass; in fact the internet has insured the opposite scenario has come to pass. There is no big brother but we are all looking over each other’s shoulder all the time, while at the same time a number of big corporations are capturing and selling all this collective endeavour back to us.