908 resultados para Positional concerns
Resumo:
We revisit the venerable question of access credentials management, which concerns the techniques that we, humans with limited memory, must employ to safeguard our various access keys and tokens in a connected world. Although many existing solutions can be employed to protect a long secret using a short password, those solutions typically require certain assumptions on the distribution of the secret and/or the password, and are helpful against only a subset of the possible attackers. After briefly reviewing a variety of approaches, we propose a user-centric comprehensive model to capture the possible threats posed by online and offline attackers, from the outside and the inside, against the security of both the plaintext and the password. We then propose a few very simple protocols, adapted from the Ford-Kaliski server-assisted password generator and the Boldyreva unique blind signature in particular, that provide the best protection against all kinds of threats, for all distributions of secrets. We also quantify the concrete security of our approach in terms of online and offline password guesses made by outsiders and insiders, in the random-oracle model. The main contribution of this paper lies not in the technical novelty of the proposed solution, but in the identification of the problem and its model. Our results have an immediate and practical application for the real world: they show how to implement single-sign-on stateless roaming authentication for the internet, in a ad-hoc user-driven fashion that requires no change to protocols or infrastructure.
Resumo:
Increasingly the fields of Human Computer Interaction (HCI) and art are intersecting. Interactive artworks are being evaluated by HCI methods and artworks are being created that employ and repurpose technology for interactive environments. In this paper we steer a path between empirical and critical–theoretical traditions, and discuss HCI research and art works that also span this divide. We address concerns about ‘new’ ethnography raised by Crabtree et al. (2009) in “Ethnography Considered Harmful”, a critical essay that positions ethnographic and critical-theoretical views at odds with each other. We propose a mediated view for understanding interactions within open-ended interactive artworks that values both perspectives as we navigate boundaries between art practice and HCI.
Resumo:
This paper describes a novel obstacle detection system for autonomous robots in agricultural field environments that uses a novelty detector to inform stereo matching. Stereo vision alone erroneously detects obstacles in environments with ambiguous appearance and ground plane such as in broad-acre crop fields with harvested crop residue. The novelty detector estimates the probability density in image descriptor space and incorporates image-space positional understanding to identify potential regions for obstacle detection using dense stereo matching. The results demonstrate that the system is able to detect obstacles typical to a farm at day and night. This system was successfully used as the sole means of obstacle detection for an autonomous robot performing a long term two hour coverage task travelling 8.5 km.
Resumo:
Sudden, violent and otherwise unexplained deaths are investigated in most western jurisdictions through a Coronial or medico-legal process. A crucial element of such an investigation is the legislative requirement to remove the body for autopsy and other medical interventions, processes which can disrupt traditional religious and cultural grieving practices. While recent legislative changes in an increasing number of jurisdictions allow families to raise objections based on religious and cultural grounds, such concerns can be over-ruled, often exacerbating the trauma and grief of families. Based on funded research which interviews a range of Coronial staff in one Australian jurisdiction, this paper explores the disjuncture between medico-legal discourses, which position the body as corpse, and the rise of more ‘therapeutic’ discourses which recognise the family’s wishes to reposition the body as beloved and lamented.
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The writing of award winning tartan noir author, Denise Mina, “crime queen of Glasgow” has been identified with “explicitly feminist politics,” and Mina herself claims, as a feminist, she wants to use crime fiction to present a “narrative about very disempowered people becoming empowered.” This paper explores how Mina’s avowed stance on feminism plays out in her novel, The Field of Blood (2005), and examines whether her concerns are reflected in the embodied actions of her young protagonist, would-be investigative journalist, Paddy Meehan. It asks whether Mina has succeeded in working against entrenched patriarchal codes of crime fiction’s dominant narrative construction or whether her feminist intentions have been undermined by traditional stereotypical conventions of the genre.
Resumo:
Installation of domestic rooftop photovoltaic cells (PVs) is increasing due to feed–in tariff and motivation driven by environmental concerns. Even though the increase in the PV installation is gradual, their locations and ratings are often random. Therefore, such single–phase bi–directional power flow caused by the residential customers can have adverse effect on the voltage imbalance of a three–phase distribution network. In this chapter, a voltage imbalance sensitivity analysis and stochastic evaluation are carried out based on the ratings and locations of single–phase grid–connected rooftop PVs in a residential low voltage distribution network. The stochastic evaluation, based on Monte Carlo method, predicts a failure index of non–standard voltage imbalance in the network in presence of PVs. Later, the application of series and parallel custom power devices are investigated to improve voltage imbalance problem in these feeders. In this regard, first, the effectiveness of these two custom power devices is demonstrated vis–à–vis the voltage imbalance reduction in feeders containing rooftop PVs. Their effectiveness is investigated from the installation location and rating points of view. Later, a Monte Carlo based stochastic analysis is utilized to investigate their efficacy for different uncertainties of load and PV rating and location in the network. This is followed by demonstrating the dynamic feasibility and stability issues of applying these devices in the network.
Resumo:
Espionage, surveillance and clandestine operations by secret agencies and governments were something of an East–West obsession in the second half of the twentieth century, a fact reflected in literature and film. In the twenty-first century, concerns of the Cold War and the threat of Communism have been rearticulated in the wake of 9/11. Under the rubric of ‘terror’ attacks, the discourses of security and surveillance are now framed within an increasingly global context. As this article illustrates, surveillance fiction written for young people engages with the cultural and political tropes that reflect a new social order that is different from the Cold War era, with its emphasis on spies, counter espionage, brainwashing and psychological warfare. While these tropes are still evident in much recent literature, advances in technology have transformed the means of tracking, profiling and accumulating data on individuals’ daily activities. Little Brother, The Hunger Games and Article 5 reflect the complex relationship between the real and the imaginary in the world of surveillance and, as this paper discusses, raise moral and ethical issues that are important questions for young people in our age of security.
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One of the concerns about the use of Bluetooth MAC Scanner (BMS) data, especially from urban arterial, is the bias in the travel time estimates from multiple Bluetooth devices being transported by a vehicle. For instance, if a bus is transporting 20 passengers with Bluetooth equipped mobile phones, then the discovery of these mobile phones by BMS will be considered as 20 different vehicles, and the average travel time along the corridor estimated from the BMS data will be biased with the travel time from the bus. This paper integrates Bus Vehicle Identification system with BMS network to empirically evaluate such bias, if any. The paper also reports an interesting finding on the uniqueness of MAC IDs.
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Previous studies have shown that the human lens contains glycerophospholipids with ether linkages. These lipids differ from conventional glycerophospholipids in that the sn-1 substituent is attached to the glycerol backbone via an 1-O-alkyl or an 1-O-alk-1'-enyl ether rather than an ester bond. The present investigation employed a combination of collision-induced dissociation (CID) and ozone-induced dissociation (OzID) to unambiguously distinguish such 1-O-alkyl and 1-O-alk-1'-enyl ethers. Using these methodologies the human lens was found to contain several abundant 1-O-alkyl glycerophos-phoethanolamines, including GPEtn(16:0e/9Z-18:1), GPEtn(11Z-18:1e/9Z-18:1), and GPEtn(18:0e/9Z-18:1), as well as a related series of unusual 1-O-alkyl glycerophosphoserines, including GPSer(16:0e/9Z-18:1), GPSer(11Z-18:1e/9Z-18:1), GPSer(18:0e/9Z-18:1) that to our knowledge have not previously been observed in human tissue. Isomeric 1-O-alk-1'-enyl ethers were absent or in low abundance. Examination of the double bond position within the phospholipids using OzID revealed that several positional isomers were present, including sites of unsaturation at the n-9, n-7, and even n-5 positions. Tandem CID/OzID experiments revealed a preference for double bonds in the n-7 position of 1-O-ether linked chains, while n-9 double bonds predominated in the ester-linked fatty acids [e.g., GPEtn(11Z-18:1e/9Z-18:1) and GPSer(11Z-18:1e/9Z-18:1)]. Different combinations of these double bond positional isomers within chains at the sn-1 and sn-2 positions point to a remarkable molecular diversity of ether-lipids within the human lens.
Resumo:
The increasing growth in the use of Hardware Security Modules (HSMs) towards identification and authentication of a security endpoint have raised numerous privacy and security concerns. HSMs have the ability to tie a system or an object, along with its users to the physical world. However, this enables tracking of the user and/or an object associated with the HSM. Current systems do not adequately address the privacy needs and as such are susceptible to various attacks. In this work, we analyse various security and privacy concerns that arise when deploying such hardware security modules and propose a system that allow users to create pseudonyms from a trusted master public-secret key pair. The proposed system is based on the intractability of factoring and finding square roots of a quadratic residue modulo a composite number, where the composite number is a product of two large primes. Along with the standard notion of protecting privacy of an user, the proposed system offers colligation between seemingly independent pseudonyms. This new property when combined with HSMs that store the master secret key is extremely beneficial to a user, as it offers a convenient way to generate a large number of pseudonyms using relatively small storage requirements.
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Living City 2013 Workshop, as part of a school term’s design-based curriculum connected to the KGSC/QUT Design Excellence Program and run from 11 February – 1 May, 2013, was essentially a three-day place-based urban design immersion workshop program for 25 Year 11 Visual Art and Design Students and 2 Teachers from Kelvin Grove State College (KGSC) held at both Queensland University of Technology (QUT) Gardens Point Campus and The Edge, State Library of Queensland. Mentored by 4 design professionals, 2 tertiary design academics, 2 public artists, and 12 QUT tertiary design students, the workshop explored youth-inspired public space design solutions for the active Brisbane City Council redevelopment site of Queens Wharf Road precinct. As well as the face-to-face workshops, for Living City 2013, an interactive web environment was introduced to enable students to connect with each other and program mentors throughout the course of the program. The workshop, framed within notions of ecological, economic, social and cultural sustainability, aimed to raise awareness of the layered complexity and perspectives involved in the design of shared city spaces and to encourage young people to voice their own concerns as future citizens about the shape and direction of their city. The program commenced with an introductory student briefing by stakeholders and mentors at KGSC on 11 February, an introduction to site appraisal and site visit held at QUT and Queens Wharf Road on 20 February, and a follow up site analysis session on 6 March. Day 1 Workshop on April 17 at the Edge, State Library of Queensland, as part of the Design Minds partnership (http://designminds.org.au/kelvin-grove-state-college-excellence-in-art-design/), focused on mentoring team development of a concept design for a range of selected sites. Two workshops on April 22 and 23 at QUT, to develop these designs and presentation schemes, followed this. The workshop program culminated in a visual presentation of concept design ideas and discussion with a public audience in the Ideas Gallery on The Deck, King George Square during the Brisbane City Council City Centre Master Plan Ideas Fiesta on 1 May, 2013, as referenced in the Ideas Fiesta Wrap-up Report (http://www.brisbane.qld.gov.au/planning-building/planning-guidelines-tools/city-centre-master-plan/city-centre-master-plan-ideas-fiesta). Students were introduced to design methodology, team thinking strategies, the scope of design practices and professions, presentation skills and post-secondary pathways, while participating teachers acquired content and design learning strategies transferable in many other contexts. The program was fully documented on the Living City website (http://www.livingcity.net.au/LC2013x/index.html) and has been recognised by the Brisbane City Council Youth Strategy 2014-2019 as a best practice model for making Brisbane a well-designed, subtropical city.
Resumo:
In order to assist with the development of more selective and sensitive methods for thyroid hormone analysis the \[M-H](-) anions of the iodothyronines T4, T3, rT3, (3,5)-T2 and the non-iodinated thyronine (TO) have been generated by negative ion electrospray mass spectrometry. Tandem mass spectra of these ions were recorded on a triple-quadrupole mass spectrometer and show a strong analogy with the fragmentation pathways of the parent compound, tyrosine. All iodothyronines also show significant abundances of the iodide anion in their tandem mass spectra, which represents an attractive target for multiple reaction monitoring (MRM) analysis, given that iodothyronines are the only iodine bearing endogenous molecules. Characteristic fragments are observed at m/z 359.7 and 604.5 for rT3 but are absent in the spectrum of T3, thus differentiating the two positional isomers. The striking difference in the fragmentation patterns of these regioisomeric species is attributed to the increased acidity of the phenol moiety in rT3 compared with T3. Copyright (C) 2005 John Wiley & Sons, Ltd.
Resumo:
Until recently, sustainable development was perceived as essentially an environmental issue, relating to the integration of environmental concerns into economic decision-making. As a result, environmental considerations have been the primary focus of sustainability decision making during the economic development process for major projects, and the assessment and preservation of social and cultural systems has been arguably too limited. The practice of social impact and sustainability assessment is an established and accepted part of project planning, however, these practices are not aimed at delivering sustainability outcomes for social systems, rather they are designed to minimise ‘unsustainability’ and contribute to project approval. Currently, there exists no widely recognised standard approach for assessing social sustainability and accounting for positive externalities of existing social systems in project decision making. As a result, very different approaches are applied around the world, and even by the same organisations from one project to another. This situation is an impediment not only to generating a shared understanding of the social implications as related to major projects, but more importantly, to identifying common approaches to help improve social sustainability outcomes of proposed activities. This paper discusses the social dimension of sustainability decision making of mega-projects, and argues that to improve accountability and transparency of project outcomes it is important to understand the characteristics that make some communities more vulnerable than others to mega-project development. This paper highlights issues with current operational level approaches to social sustainability assessment at the project level, and asserts that the starting point for project planning and sustainability decision making of mega-projects needs to include the preservation, maintenance, and enhancement of existing social and cultural systems. It draws attention to the need for a scoping mechanism to systematically assess community vulnerability (or sensitivity) to major infrastructure development during the feasibility and planning stages of a project.
Resumo:
Early childhood education has long been connected with objectives related to social justice. Australian Early Childhood Education and Care (ECEC) has its roots in philanthropic and educational reform movements prevalent at the turn of the 20th century. More recently, with the introduction of the National Early Childhood Reform Agenda, early childhood education has once more been linked to the achievement of aims associated with redressing inequality and disadvantage. According to Jean-Marie, Normore and Brooks (2009), educational leaders have a moral and social obligation to foster equitable practices through advocating for traditionally marginalised and poorly served students while creating a new social order “...that subverts the long standing system that has privileged certain students while oppressing or neglecting others” (p.4). Drawing on extant literature, including data from two previously reported Australian studies in which leadership emerged as having a transformational impact on service delivery, this paper examines the potential of early childhood leadership to generate ‘socially just’ educational communities. With reference to critical theory, we argue that critically informed, intentional and strategic organisational leadership can play a pivotal role in creating changed circumstances and opportunities for children and families. Such leadership includes positional and distributed elements, articulation of values and beliefs, and collective action that is mindful and informed.
Resumo:
Declining fossil fuels reserves, a need for increased energy security and concerns over carbon emissions from fossil fuel use are the global drivers for alternative, renewable, biosources of fuels and chemicals. In the present study the identification of long chain (C29–C33) saturated hydrocarbons from Nicotiana glauca leaves is reported. The occurrence of these hydrocarbons was detected by gas chromatography–mass spectrometry (GC–MS) and identification confirmed by comparison of physico-chemical properties displayed by the authentic standards available. A simple, robust procedure was developed to enable the generation of an extract containing a high percentage of hydrocarbons (6.3% by weight of dried leaf material) higher than previous reports in other higher plant species consequently, it is concluded that N. glauca could be a crop of greater importance than previously recognised for biofuel production. The plant can be grown on marginal lands, negating the need to compete with food crops or farmland, and the hydrocarbon extract can be produced in a non-invasive manner, leaving remaining biomass intact for bioethanol production and the generation of valuable co-products.