910 resultados para message rejection
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This paper presents a model for generating a MAC tag by injecting the input message directly into the internal state of a nonlinear filter generator. This model generalises a similar model for unkeyed hash functions proposed by Nakano et al. We develop a matrix representation for the accumulation phase of our model and use it to analyse the security of the model against man-in-the-middle forgery attacks based on collisions in the final register contents. The results of this analysis show that some conclusions of Nakano et al regarding the security of their model are incorrect. We also use our results to comment on several recent MAC proposals which can be considered as instances of our model and specify choices of options within the model which should prevent the type of forgery discussed here. In particular, suitable initialisation of the register and active use of a secure nonlinear filter will prevent an attacker from finding a collision in the final register contents which could result in a forged MAC.
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BACKGROUND The engineering profession in Australia has failed to attract young women for the last decade or so despite all the effort that have gone into promoting engineering as a preferred career choice for girls. It is a missed opportunity for the profession to flourish as a heterogeneous team. Many traditional initiatives and programs have failed to make much impact or at best incremental improvement into attracting and retaining more women in the profession. The reasons why girls and young women in most parts of the world show little interest in engineering haven't changed, despite all the efforts to address them, the issue proposed here in this paper is with the perceptions of engineering in the community and the confidence to pursue it. This gender imbalance is detrimental for the engineering profession, and hence an action-based intervention strategy was devised by the Women in Engineering Qld Chapter of Engineers Australia in 2012 to change the perceptions of school girls by redesigning the engagement strategy and key messages. As a result, the “Power of Engineering Inc” (PoE) was established as a not-for-profit organisation, and is a collaborative effort between government, schools, universities, and industry. This paper examines a case study in changing the perceptions of year 9 and 10 school girls towards an engineering career. PURPOSE To evaluate and determine the effectiveness of an intervention in changing the perceptions of year 9 and 10 school girls about engineering career options, but specifically, “What were their perceptions of engineering before today and have those perceptions changed?” DESIGN/METHOD The inaugural Power of Engineering (PoE) event was held on International Women’s Day, Thursday 8 March 2012 and was attended by 131 high school female students (year 9 and 10) and their teachers. The key message of the day was “engineering gives you the power to change the world”. A questionnaire was conducted with the participating high school female students, collecting both quantitative and qualitative data. The survey instrument has not been validated. RESULTS The key to the success of the event was as a result of collaboration between all participants involved and the connection created between government, schools, universities and industry. Of the returned surveys (109 of 131), 91% of girls would now consider a career in engineering and 57% who had not considered engineering before the day would now consider a career in engineering. Data collected found significant numbers of negative and varying perceptions about engineering careers prior to the intervention. CONCLUSIONS The evidence in this research suggests that the intervention assisted in changing the perceptions of year 9 and 10 female school students towards engineering as a career option. Whether this intervention translates into actual career selection and study enrolment is to be determined. In saying this, the evidence suggests that there is a critical and urgent need for earlier interventions prior to students selecting their subjects for year 11 and 12. This intervention could also play its part in increasing the overall pool of students engaged in STEM education.
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Murine intestinal intraepithelial lymphocytes (IEL) have been shown to contain subsets of alpha/beta TCR+ and gamma/delta TCR+ T cells that spontaneously produce cytokines such as IFN-gamma and IL-5. We have now determined the nature and cell cycle stage of these cytokine-producing T lymphocytes in EIL by using IFN-gamma- and IL-5-specific ELISPOT assay, cytokine-specific mRNA-cDNA dot-blot hybridization and polymerase chain reaction, and flow cytometry (FACS) for DNA analysis. When CD3+ T cells from IEL of normal C3H/HeN mice were separated into low and high density fractions by discontinuous Percoll gradients, IFN-gamma and IL-5 spot-forming cells were only found in the former population. Analysis of mRNA for these cytokines by both IFN-gamma- and IL-5-specific dot-blot hybridization and polymerase chain reaction revealed that higher levels of message for IFN-gamma and IL-5 were also seen in the low density fraction. However, cell cycle analysis of these two fractions by FACS using propidium iodide showed a similar pattern of cell cycle stages in both low and high density populations (G0 + G1 approximately 96 to 98% and S/G2 + M approximately 2 to 4%). Finally, mRNA from gamma/delta TCR+ and alpha/beta TCR+ T cells in both low and high density fractions of IEL were analyzed for IFN-gamma and IL-5 message by polymerase chain reaction. After 35 cycles of amplification, both gamma/delta TCR+ and alpha/beta TCR+ T cells in the low density fraction expressed higher levels of message for these two cytokines when compared with the high density population. These results have now shown that both gamma/delta and alpha/beta TCR+ IEL can be separated into low and high density subsets and both fractions possess a similar stage of cell cycle. However, only the low density cells (in G1 phase) of both gamma/delta and alpha/beta TCR types possess increased cytokine-specific mRNA and produce the cytokines IFN-gamma and IL-5. Our results suggest that alpha/beta TCR+ and gamma/delta TCR+ IEL can produce cytokines without cell proliferation.
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Objective To explore whether improvements in physical activity following the MobileMums intervention were mediated by changes in Social Cognitive Theory (SCT) constructs targeted in the intervention (barrier self efficacy, goal setting skills, outcome expectancy, social support, and perceived environmental opportunity for exercise). This paper also examined if the mediating constructs differed between initial (baseline to 6 weeks) and overall (baseline to 13 weeks) changes in physical activity. Methods Secondary analysis of data from a randomized controlled trial involving 88 postnatal women (<12 months postpartum). Participants were randomized to receive either the 12-week MobileMums intervention or a minimal-contact control condition. Physical activity and proposed mediators were assessed by self-report at baseline, 6 weeks, and 13 weeks. Walking for Exercise frequency was assessed using the Australian Women's Activity Survey and frequency of moderate-to-vigorous physical activity (MVPA) was assessed using a single-item question. Results Initial improvements in goal-setting skills mediated the relationship between experimental condition and initial changes in MVPA, αβ (95% CI) = 0.23(0.01, 0.59), and Walking for Exercise, αβ (95% CI) = 0.34(0.06, 0.73). Initial improvements in barrier self efficacy mediated the relationship between experimental condition and initial change in MVPA, αβ (95% CI) = 0.36(0.12, 0.65), but not Walking for Exercise. None of the SCT outcomes significantly mediated the relationship between experimental condition and overall (baseline to 13 weeks) change in frequency of MVPA or Walking for Exercise. Conclusion Future interventions with postnatal women using SCT should target barrier self-efficacy and goal setting skills in order to increase physical activity. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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A Delay Tolerant Network (DTN) is one where nodes can be highly mobile, with long message delay times forming dynamic and fragmented networks. Traditional centralised network security is difficult to implement in such a network, therefore distributed security solutions are more desirable in DTN implementations. Establishing effective trust in distributed systems with no centralised Public Key Infrastructure (PKI) such as the Pretty Good Privacy (PGP) scheme usually requires human intervention. Our aim is to build and compare different de- centralised trust systems for implementation in autonomous DTN systems. In this paper, we utilise a key distribution model based on the Web of Trust principle, and employ a simple leverage of common friends trust system to establish initial trust in autonomous DTN’s. We compare this system with two other methods of autonomously establishing initial trust by introducing a malicious node and measuring the distribution of malicious and fake keys. Our results show that the new trust system not only mitigates the distribution of fake malicious keys by 40% at the end of the simulation, but it also improved key distribution between nodes. This paper contributes a comparison of three de-centralised trust systems that can be employed in autonomous DTN systems.
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This paper describes and explains the social worlds of a group of young Murris who are engaged in chroming (paint sniffing) and who sleep rough in inner Brisbane. In particular, the paper considers the ways young Indigenous drug users describe their marginalisation from wider society and its structures of opportunity, but it also includes some reflections from their youth worker and a young man who frequents the young people’s squat. The paper demonstrates the centrality of racism and material disadvantage to the experience of a group of young Aboriginal and Torres Strait Islander sniffers, a perspective largely unreflected in the literature on Indigenous volatile substance misuse. Further, the young people’s ways of interacting with the broader society are described to explain the ways their rejection of mainstream norms form a significant political response to their marginality and reflect, at least in part, the wider Indigenous historical experience. The work draws on theories of alienation and subculture to analyse the young people’s descriptions of their social estrangement and the formation of the ‘paint sniffer group’. It is concluded that paint sniffing among urban Indigenous youth is, at least in part, an obnoxious and encoded distillation of a wider Indigenous rebuttal of broader societal norms, and that the dominant — normalising — modes of treatment risk further alienating an already oppositional group of young people.
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In recent years, some models have been proposed for the fault section estimation and state identification of unobserved protective relays (FSE-SIUPR) under the condition of incomplete state information of protective relays. In these models, the temporal alarm information from a faulted power system is not well explored although it is very helpful in compensating the incomplete state information of protective relays, quickly achieving definite fault diagnosis results and evaluating the operating status of protective relays and circuit breakers in complicated fault scenarios. In order to solve this problem, an integrated optimization mathematical model for the FSE-SIUPR, which takes full advantage of the temporal characteristics of alarm messages, is developed in the framework of the well-established temporal constraint network. With this model, the fault evolution procedure can be explained and some states of unobserved protective relays identified. The model is then solved by means of the Tabu search (TS) and finally verified by test results of fault scenarios in a practical power system.
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A complex attack is a sequence of temporally and spatially separated legal and illegal actions each of which can be detected by various IDS but as a whole they constitute a powerful attack. IDS fall short of detecting and modeling complex attacks therefore new methods are required. This paper presents a formal methodology for modeling and detection of complex attacks in three phases: (1) we extend basic attack tree (AT) approach to capture temporal dependencies between components and expiration of an attack, (2) using enhanced AT we build a tree automaton which accepts a sequence of actions from input message streams from various sources if there is a traversal of an AT from leaves to root, and (3) we show how to construct an enhanced parallel automaton that has each tree automaton as a subroutine. We use simulation to test our methods, and provide a case study of representing attacks in WLANs.
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Complex Internet attacks may come from multiple sources, and target multiple networks and technologies. Nevertheless, Collaborative Intrusion Detection Systems (CIDS) emerges as a promising solution by using information from multiple sources to gain a better understanding of objective and impact of complex Internet attacks. CIDS also help to cope with classical problems of Intrusion Detection Systems (IDS) such as zero-day attacks, high false alarm rates and architectural challenges, e. g., centralized designs exposing the Single-Point-of-Failure. Improved complexity on the other hand gives raise to new exploitation opportunities for adversaries. The contribution of this paper is twofold. We first investigate related research on CIDS to identify the common building blocks and to understand vulnerabilities of the Collaborative Intrusion Detection Framework (CIDF). Second, we focus on the problem of anonymity preservation in a decentralized intrusion detection related message exchange scheme. We use techniques from design theory to provide multi-path peer-to-peer communication scheme where the adversary can not perform better than guessing randomly the originator of an alert message.
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This tutorial is designed to assist users who wish to use the LCD screen on the Spartan-3E board. In this tutorial, the PicoBlaze microcontroller is used to control the LCD. The tutorial is organised into three Parts. In Part A, code is written to display the message "Hello World" on the LCD. Part B demonstrates how to define and display custom characters. Finally, Part C shows how the display can be shifted and flashed. Shifting is done by using a delay in the main PicoBlaze program loop, while flashing is done using the PicoBlaze interrupt. The slider switches can be used to select the shifting direction, and to turn shifting and flashing on and off.
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We propose CIMD (Collaborative Intrusion and Malware Detection), a scheme for the realization of collaborative intrusion detection approaches. We argue that teams, respectively detection groups with a common purpose for intrusion detection and response, improve the measures against malware. CIMD provides a collaboration model, a decentralized group formation and an anonymous communication scheme. Participating agents can convey intrusion detection related objectives and associated interests for collaboration partners. These interests are based on intrusion objectives and associated interests for collaboration partners. These interests are based on intrusion detection related ontology, incorporating network and hardware configurations and detection capabilities. Anonymous Communication provided by CIMD allows communication beyond suspicion, i.e. the adversary can not perform better than guessing an IDS to be the source of a message at random. The evaluation takes place with the help of NeSSi² (www.nessi2.de), the Network Security Simulator, a dedicated environment for analysis of attacks and countermeasures in mid-scale and large-scale networks. A CIMD prototype is being built based on the JIAC agent framework(www.jiac.de).
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Background: Evidence demonstrates self-management programs are an effective approach to assist patients with chronic diseases such as type 2 diabetes or cardiac conditions to modify their lifestyle for better managing their conditions. Using information technology (IT) has great potential to support self-management programs and assist patients to fulfill their goals in managing their conditions more efficiently and effectively. Examples of different types of technology used in self-management programs that have limited research support include: text messages, telephone followup, web-based programs, and other internet-assisted education. But little is known about the applicability and feasiability of different forms of technology for patients with chronic diseases such as those with type 2 diabetes and critical cardiac conditions. Furthermore, although there is some evidence of the benefits of using IT in supporting self-management programs, further research on the use of IT in such programs is recommended. Objective: To develop and pilot test an integrated Cardiac- Diabetes Self-Management Program (CDSMP) incorporating telephone and text-message follow-up. Methods: A pilot study using randomised controlled trial is conducted in the coronary care unit (CCU) in a Brisbane metropolitan hospital in Australia to collect data on patients with type 2 diabetes admitted to CCU. The main outcomes included self-efficacy levels, knowledge, and quality of life. Results: Initial results reveal that patients with diabetes admitted to the CCU in the experimental group did improve their self-efficacy, and knowledge levels. Acknowledgements: This Project is funded by QUT Early Career Researcher Research Grant
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Identity-Based (IB) cryptography is a rapidly emerging approach to public-key cryptography that does not require principals to pre-compute key pairs and obtain certificates for their public keys— instead, public keys can be arbitrary identifiers such as email addresses, while private keys are derived at any time by a trusted private key generator upon request by the designated principals. Despite the flurry of recent results on IB encryption and signature, some questions regarding the security and efficiency of practicing IB encryption (IBE) and signature (IBS) as a joint IB signature/encryption (IBSE) scheme with a common set of parameters and keys, remain unanswered. We first propose a stringent security model for IBSE schemes. We require the usual strong security properties of: (for confidentiality) indistinguishability against adaptive chosen-ciphertext attacks, and (for nonrepudiation) existential unforgeability against chosen-message insider attacks. In addition, to ensure as strong as possible ciphertext armoring, we also ask (for anonymity) that authorship not be transmitted in the clear, and (for unlinkability) that it remain unverifiable by anyone except (for authentication) by the legitimate recipient alone. We then present an efficient IBSE construction, based on bilinear pairings, that satisfies all these security requirements, and yet is as compact as pairing-based IBE and IBS in isolation. Our scheme is secure, compact, fast and practical, offers detachable signatures, and supports multirecipient encryption with signature sharing for maximum scalability.
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The recent decision of the Court of Appeal in AGL Sales (Qld) Pty Ltd v Dawson Sales Pty Ltd [2009] QCA 262 provides clear direction on the Court’s expectations of a party seeking leave to appeal a costs order.This decision is likely to impact upon common practice in relation to appeals against costs orders. It sends a clear message to trial judges that they should not give leave as of course when giving a judgment in relation to costs, and that parties seeking leave under s 253 of the Supreme Court Act 1995 (Qld) should make a separate application. The application should be supported by material presenting an arguable case that the trial judge made an error in the exercise of the discretion of the kind described in House v King (1936) 55 CLR 499. A different, and interesting, aspect of this appeal is that it was the first wholly electronic civil appeal. The court-provided technology had been adopted at trial, and the Court of Appeal dispensed with any requirement for hard copy appeal record books.
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The Second Skin 2012 Workshop Program consisted of a full-day intensive design immersion workshop run on Saturday 14 July 2012, at the QUT Faculty of Creative Industries Fashion Studios at Kelvin Grove Brisbane, Australia, for 30? self-selected high-achieving junior and middle school (year 5-9) students, as part of the Queensland Academies ‘Young Scholars’ Program. Inspired by a scientist researching the impact of sun on skin, and mentored by tertiary fashion design and interior design educators, and six tertiary fashion design and interior design students, the workshop explored science and design-inspired prototype solutions for sun-safety. This action research study aimed to facilitate an acute awareness in young people of the sun safety message (alternative to a scare campaign), the role of design in society and the value of design thinking skills in solving complex challenges, and to inspire the generation of strategies to address a systemic health issue. It also aimed to investigate the value of collaboration between junior and middle school students, tertiary design educators and students and industry professionals in targeting youth sun safety, and inspiring post-secondary pathways and idea generation for education. During the workshop, students developed sketching, making, communication, presentation and collaboration skills to improve their design process, while considering social, cultural and environmental opportunities. Through a series of hands-on collaborative design experiments, participants explored in teams of five, ways in which a ‘second skin’ can mirror elements of our skin – the ability to protect, divide, enclose, stretch, scar, pattern, peel and reveal – inspiring both functional and aesthetic design solutions. Underpinned by the State Library of Queensland Design Minds Website ‘inquire, ideate and implement’ model of design thinking, the experiments culminated in the development of a detailed client brief, the design and fabrication of a fashionable sun safe clothing range and then a team presentation and modelling of prototypes in a fashion parade, viewed also by parents. The final collections were judged by three prominent judges: Louise Baldwin - Executive Manager Public Health QLD Cancer Council, Shane Thompson - Architect and 2012 Queensland Smart Design Fellow, and Leigh Buchanan – Fashion designer and Project Runway Australia finalist. The workshop was filmed for Queensland television program ‘Totally Wild’ for dissemination of the value of design, the Design Minds model and the sun safety message to a wider target youth audience.