994 resultados para forward speed
Resumo:
Most one-round key exchange protocols provide only weak forward secrecy at best. Furthermore, one-round protocols with strong forward secrecy often break badly when faced with an adversary who can obtain ephemeral keys. We provide a characterisation of how strong forward secrecy can be achieved in one-round key exchange. Moreover, we show that protocols exist which provide strong forward secrecy and remain secure with weak forward secrecy even when the adversary is allowed to obtain ephemeral keys. We provide a compiler to achieve this for any existing secure protocol with weak forward secrecy.
Resumo:
In the past, training in clinical psychology in Australia and overseas has been dominated by definitions of input— hours of classes or supervision and of specific components. While prospective practitioners have been required to demonstrate the acquisition of generic competencies, satisfaction of these input driven criteria has been required for both accreditation and registration. Ironically, for a discipline that prides itself on requiring empirical bases for practice and communicating those to students (Calhoun, Moras, Pilkonis, & Rehm, 1998), training criteria have been primarily derived from accepted wisdom, rather than from a sound body of data. The situation has been remarkably like that of a treatment establishing standards of fidelity before its effective components are known—an action our profession has correctly criticised in the past (Herbert & Mueser, 1992).
Resumo:
The high attrition rate of beginning teachers in Australia and overseas is well-documented. This trend is easily understood as many beginning teachers enter the profession with little support or mentoring (Department of Education, Science and Training (DEST), 2002; Herrington & Herrington, 2004; Ramsey, 2000). Continual calls for more comprehensive approaches to teacher induction in which universities and employing bodies share the responsibilities of the transition to professional practice (House of Representatives Standing Committee on Education and Vocational Training, 2007) have, to date, largely been ignored. This paper reports on a trial project conducted at a university in south-east Queensland, Australia that addresses these shortfalls. The aim of the project is to facilitate and support the development of high quality teachers and teaching through an extended model of teacher preparation. The model comprises a 1+2 program of formal teacher preparation: a one-year teacher education course (the Graduate Diploma in Education), followed by a comprehensive two year program of workplace induction and ongoing professional learning tailored to meet graduate and employer needs. This paper reports on graduating students’ perceptions of their preparedness to teach as they transition from the Graduate Diploma in Education program to professional practice. The study concludes that innovative programs, including university-linked, ongoing professional learning support for teacher education graduates, may provide the way forward for enhancing the transition to practice for beginning teachers.
Resumo:
Just Fast Keying (JFK) is a simple, efficient and secure key exchange protocol proposed by Aiello et al. (ACM TISSEC, 2004). JFK is well known for its novel design features, notably its resistance to denial-of-service (DoS) attacks. Using Meadows’ cost-based framework, we identify a new DoS vulnerability in JFK. The JFK protocol is claimed secure in the Canetti-Krawczyk model under the Decisional Diffie-Hellman (DDH) assumption. We show that security of the JFK protocol, when reusing ephemeral Diffie-Hellman keys, appears to require the Gap Diffie-Hellman (GDH) assumption in the random oracle model. We propose a new variant of JFK that avoids the identified DoS vulnerability and provides perfect forward secrecy even under the DDH assumption, achieving the full security promised by the JFK protocol.
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In this paper we analyze the performance degradation of slotted amplify-and-forward protocol in wireless environments with high node density where the number of relays grows asymptotically large. Channel gains between source-destination pairs in such networks can no longer be independent. We analyze the degradation of performance in such wireless environments where channel gains are exponentially correlated by looking at the capacity per channel use. Theoretical results for eigenvalue distribution and the capacity are derived and compared with the simulation results. Both analytical and simulated results show that the capacity given by the asymptotic mutual information decreases with the network density.
Resumo:
High Speed Rail (HSR) is rapidly gaining popularity worldwide as a safe and efficient transport option for long-distance travel. Designed to win market shares from air transport, HSR systems optimise their productivity between increasing speeds and station spacing to offer high quality service and gain ridership. Recent studies have investigated the effects that the deployment of HSR infrastructure has on spatial distribution and the economic development of cities and regions. Findings appear mostly positive at higher geographical scales, where HSR links connect major urban centres several hundred kilometres apart and already well positioned within a national or international context. Also, at the urban level, studies have shown regeneration and concentration effects around HSR station areas with positive returns on city’s image and economy. However, doubts persist on the effects of HSR at an intermediate scale, where the accessibility trade off on station spacing limits access to many small and medium agglomerations. Thereby, their ability to participate in the development opportunities facilitated by HSR infrastructure is significantly reduced. The locational advantages deriving from transport improvements appear contrasting especially in regions that tend to have a polycentric structure, where cities may present greater accessibility disparities between those served by HSR and those left behind. This thesis fits in this context where intermediate and regional cities do not directly enjoy the presence of an HSR station while having an existing or planned proximate HSR corridor. With the aim of understanding whether there might be a solution to this apparent incongruity, the research investigates strategies to integrate HSR accessibility at the regional level. While current literature recommends to commit with ancillary investments to the uplift of station areas and the renewal of feeder systems, I hypothesised the interoperability between the HSR and the conventional networks to explore the possibilities offered by mixed traffic and infrastructure sharing. Thus, I developed a methodology to quantify the exchange of benefits deriving from this synergistic interaction. In this way, it was possible to understand which level of service quality offered by alternative transit strategies best facilitates the distribution of accessibility benefits for areas far from actual HSR stations. Therefore, strategies were selected for their type of service capable of regional extensions and urban penetrations, while incorporating a combination of specific advantages (e.g. speed, sub-urbanity, capacity, frequency and automation) in order to emulate HSR quality with increasingly efficient services. The North-eastern Italian macro region was selected as case study to ground the research offering concurrently a peripheral polycentric metropolitan form, the presence of a planned HSR corridor with some portions of HSR infrastructure implementation, and the project to develop a suburban rail service extended regionally. Results show significant distributive potential, in terms of network effects produced in relation with HSR, in increasing proportions for all the strategies considered: a regional metro rail strategy (abbreviated RMR), a regional high speed rail strategy (abbreviated RHSR), a regional light rail transit (abbreviated LRT) strategy, and a non-stopping continuous railway system (abbreviated CRS) strategy. The provision of additional tools to value HSR infrastructure against its accessibility benefits and their regional distribution through alternative strategies beyond the actual HSR stations, would have great implications, both politically and technically, in moving towards new dimensions of HSR evaluation and development.
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This final report outlines the research conducted by the Centre for Accident Research and Road Safety – Queensland (CARRS-Q) for the research project (title above). This report provides an outline of the project methodology, literature review, three stages of research results (including the focus group discussions, review of organisational records, documentation and initiatives, and analysis of previous CARRS-Q occupational road safety self-report surveys), and recommendations for intervention strategy and initiatives development and implementation.
Resumo:
The Australian government, and opposition, are committed to facilitating high-speed broadband provision. In April 2009 the (then) Labor government announced a proposal to facilitate provision by mandating “…the use of fibre optic infrastructure … in greenfield estates ….” Separately, the installation of (usually overhead) cables commenced in select brownfield areas throughout Australia. In the lead up to the 2010 federal election, the broadband policy focus of the (then) federal opposition was to enabling private investment rather than direct investment by government itself. High-speed broadband is essential for Australia’s economic future. Whether implementation is undertaken by government, government owned corporations or private investors, will impact on the processes to be followed. Who does what, also will determine the rights available to land owners. The next stage, of necessity, will involve the establishment of procedures to require the retrofitting of existing urban environments. This clearly will have major property, property rights and valuation impacts. As Horan (2000) observed “…preserving... unique characteristics … of…regions requires a compromise between economic ambitions and social, cultural, and environmental values”. The uncertainty following the federal election, and the influence of independants with individual agendas; presents unique challenges for broadband implementation. This paper seeks to identify the processes to be followed by various potential broadband investors as they work to establish a ubiquitous network. It overviews current legislative regimes and examines concerns raised by stakeholders in various government reviews. It concludes by plotting a clear way forward to the future, with particular regard to property rights and usage.
Resumo:
Background When observers are asked to identify two targets in rapid sequence, they often suffer profound performance deficits for the second target, even when the spatial location of the targets is known. This attentional blink (AB) is usually attributed to the time required to process a previous target, implying that a link should exist between individual differences in information processing speed and the AB. Methodology/Principal Findings The present work investigated this question by examining the relationship between a rapid automatized naming task typically used to assess information-processing speed and the magnitude of the AB. The results indicated that faster processing actually resulted in a greater AB, but only when targets were presented amongst high similarity distractors. When target-distractor similarity was minimal, processing speed was unrelated to the AB. Conclusions/Significance Our findings indicate that information-processing speed is unrelated to target processing efficiency per se, but rather to individual differences in observers' ability to suppress distractors. This is consistent with evidence that individuals who are able to avoid distraction are more efficient at deploying temporal attention, but argues against a direct link between general processing speed and efficient information selection.
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Social entrepreneurship can be conceived generally as a creative force born to address emergent or longstanding unfulfilled community needs occurring within or across the non-profit, business or government sectors. In this paper, we consider the current case study of a collective comprising a non-profit community organisation, pro-bono design group and university researchers and its attempts to negotiate the tension between social innovation and social entrepreneurship in order to address the lack of suitable options for independent living for individuals with disabilities and their families. With much of the developed world coming to terms with a rapidly aging population, and increased survival rates for individuals with disabilities, there has never been a more opportune time to consider work such as this which attempts to address social and market gaps in a socially innovative and inclusive way.
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- Speeding and crash involvement in Australia - Speed management in Australia - Jurisdictional differences - National Road Safety Strategy (2011-2020) - Auditor-General reviews of speed camera programs - The role of public opinion/feedback - Implications for speed management