236 resultados para delay-free observers
The suffix-free-prefix-free hash function construction and its indifferentiability security analysis
Resumo:
In this paper, we observe that in the seminal work on indifferentiability analysis of iterated hash functions by Coron et al. and in subsequent works, the initial value (IV) of hash functions is fixed. In addition, these indifferentiability results do not depend on the Merkle–Damgård (MD) strengthening in the padding functionality of the hash functions. We propose a generic n -bit-iterated hash function framework based on an n -bit compression function called suffix-free-prefix-free (SFPF) that works for arbitrary IV s and does not possess MD strengthening. We formally prove that SFPF is indifferentiable from a random oracle (RO) when the compression function is viewed as a fixed input-length random oracle (FIL-RO). We show that some hash function constructions proposed in the literature fit in the SFPF framework while others that do not fit in this framework are not indifferentiable from a RO. We also show that the SFPF hash function framework with the provision of MD strengthening generalizes any n -bit-iterated hash function based on an n -bit compression function and with an n -bit chaining value that is proven indifferentiable from a RO.
Resumo:
Objective The aim of this study was to explore the mediating and moderating relationships between emotional perceptions of coeliac disease, negative emotional states, emotion regulation, emotional eating and gluten-free diet adherence. Method Adults with coeliac disease (N = 253) were recruited from state organisations of Coeliac Australia and completed an online questionnaire measuring illness perceptions, emotion regulation strategies, negative emotional states, emotional eating and gluten-free diet adherence. Results Participants' levels of depression and anxiety, but not stress or emotional eating, were associated with gluten-free diet adherence. Emotional perception of coeliac disease was also associated with gluten-free diet adherence, and this relationship was partially mediated by depression and anxiety. Furthermore, the emotion regulation strategies of cognitive reappraisal and expressive suppression moderated the relationship between emotional perceptions and depression, but not emotional perceptions and anxiety. Conclusions Interventions to improve dietary adherence for adults with coeliac disease displaying depressive symptoms should aim to increase the use of cognitive reappraisal and reduce the use of expressive suppression. Future studies should also explore mechanisms that may moderate the relationship between emotional perceptions and anxiety.
Resumo:
This invention concerns the control of rotating excavation machinery, for instance to avoid collisions with obstacles. In a first aspect the invention is a control system for autonomous path planning in excavation machinery, comprising: A map generation subsystem to receive data from an array of disparate and complementary sensors to generate a 3-Dimensional digital terrain and obstacle map referenced to a coordinate frame related to the machine's geometry, during normal operation of the machine. An obstacle detection subsystem to find and identify obstacles in the digital terrain and obstacle map, and then to refine the map by identifying exclusion zones that are within reach of the machine during operation. A collision detection subsystem that uses knowledge of the machine's position and movements, as well as the digital terrain and obstacle map, to identify and predict possible collisions with itself or other obstacles, and then uses a forward motion planner to predict collisions in a planned path. And, a path planning subsystem that uses information from the other subsystems to vary planned paths to avoid obstacles and collisions. In other aspects the invention is excavation machinery including the control system; a method for control of excavation machinery; and firmware and software versions of the control system.
Resumo:
An experimental study has been performed to investigate the ignition delay of a modern heavy-duty common-rail diesel engine run with fumigated ethanol substitutions up to 40% on an energy basis. The ignition delay was determined through the use of statistical modelling in a Bayesian framework this framework allows for the accurate determination of the start of combustion from single consecutive cycles and does not require any differentiation of the in-cylinder pressure signal. At full load the ignition delay has been shown to decrease with increasing ethanol substitutions and evidence of combustion with high ethanol substitutions prior to diesel injection have also been shown experimentally and by modelling. Whereas, at half load increasing ethanol substitutions have increased the ignition delay. A threshold absolute air to fuel ratio (mole basis) of above ~110 for consistent operation has been determined from the inter-cycle variability of the ignition delay, a result that agrees well with previous research of other in-cylinder parameters and further highlights the correlation between the air to fuel ratio and inter-cycle variability. Numerical modelling to investigate the sensitivity of ethanol combustion has also been performed. It has been shown that ethanol combustion is sensitive to the initial air temperature around the feasible operating conditions of the engine. Moreover, a negative temperature coefficient region of approximately 900{1050 K (the approximate temperature at fuel injection) has been shown with for n-heptane and n-heptane/ethanol blends in the numerical modelling. A consequence of this is that the dominate effect influencing the ignition delay under increasing ethanol substitutions may rather be from an increase in chemical reactions and not from in-cylinder temperature. Further investigation revealed that the chemical reactions at low ethanol substitutions are different compared to the high (> 20%) ethanol substitutions.
Resumo:
In this paper, we investigate the effect of mobility constraints on epidemic broadcast mechanisms in DTNs (Delay-Tolerant Networks). Major factors affecting epidemic broadcast performances are its forwarding algorithm and node mobility. The impact of forwarding algorithm and node mobility on epidemic broadcast mechanisms has been actively studied in the literature, but those studies generally use unconstrained mobility models. The objective of this paper is therefore to quantitatively investigate the effect of mobility constraints on epidemic broadcast mechanisms. We evaluate the performances of three classes of epidemic broadcast mechanisms - P-BCAST (PUSH-based BroadCast), SA-BCAST (Self-Adaptive BroadCast), and HP-BCAST (History-based P-BCAST) - with a random waypoint mobility model with mobility constraints. Our finding includes that the existence of mobility constraints significantly improves the reach ability and dissemination speed of epidemic broadcast mechanisms while degrading their efficiency.
Resumo:
Background: Multipotent mesenchymal stromal cells suppress T-cell function in vitro, a property that has underpinned their use in treating clinical steroid-refractory graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. However the potential of mesenchymal stromal cells to resolve graft-versus-host disease is confounded by a paucity of pre-clinical data delineating their immunomodulatory effects in vivo. Design and Methods: We examined the influence of timing and dose of donor-derived mesenchymal stromal cells on the kinetics of graft-versus-host disease in two murine models of graft-versus-host disease (major histocompatibility complex-mismatched: UBI-GFP/BL6 [H-2b]→BALB/c [H-2d] and the sibling transplant mimic, UBI-GFP/BL6 [H-2b]→BALB.B [H-2b]) using clinically relevant conditioning regimens. We also examined the effect of mesenchymal stromal cell infusion on bone marrow and spleen cellular composition and cytokine secretion in transplant recipients. Results: Despite T-cell suppression in vitro, mesenchymal stromal cells delayed but did not prevent graft-versus-host disease in the major histocompatibility complex-mismatched model. In the sibling transplant model, however, 30% of mesenchymal stromal cell-treated mice did not develop graft-versus-host disease. The timing of administration and dose of the mesenchymal stromal cells influenced their effectiveness in attenuating graft-versus-host disease, such that a low dose of mesenchymal stromal cells administered early was more effective than a high dose of mesenchymal stromal cells given late. Compared to control-treated mice, mesenchymal stromal cell-treated mice had significant reductions in serum and splenic interferon-γ, an important mediator of graft-versus-host disease. Conclusions: Mesenchymal stromal cells appear to delay death from graft-versus-host disease by transiently altering the inflammatory milieu and reducing levels of interferon-γ. Our data suggest that both the timing of infusion and the dose of mesenchymal stromal cells likely influence these cells’ effectiveness in attenuating graft-versus-host disease.
Resumo:
This paper discusses the data collection technique used to determine the skills and knowledge required of academic librarians working in a digital library environment in Australia. The research was undertaken as part of the researcher’s master’s thesis conducted at Tallinn University. The data collection instrument used was a freely available online survey tool, and its advantages and disadvantages are discussed in terms of the desired outcomes and circumstances surrounding the thesis project. Decisions regarding the design of the questionnaire are also discussed.
Resumo:
We report rapid and ultra-sensitive detection system for 2,4,6-trinitrotoluene (TNT) using unmodified gold nanoparticles and surface-enhanced Raman spectroscopy (SERS). First, Meisenheimer complex has been formed in aqueous solution between TNT and cysteamine in less than 15 min of mixing. The complex formation is confirmed by the development of a pink colour and a new UV–vis absorption band around 520 nm. Second, the developed Meisenheimer complex is spontaneously self-assembled onto unmodified gold nanoparticles through a stable Au–S bond between the cysteamine moiety and the gold surface. The developed mono layer of cysteamine-TNT is then screened by SERS to detect and quantify TNT. Our experimental results demonstrate that the SERS-based assay provide an ultra-sensitive approach for the detection of TNT down to 22.7 ng/L. The unambiguous fingerprint identification of TNT by SERS represents a key advantage for our proposed method. The new method provides high selectivity towards TNT over 2,4 DNT and picric acid. Therefore it satisfies the practical requirements for the rapid screening of TNT in real life samples where the interim 24-h average allowable concentration of TNT in waste water is 0.04 mg/L.
Resumo:
Place recognition has long been an incompletely solved problem in that all approaches involve significant compromises. Current methods address many but never all of the critical challenges of place recognition – viewpoint-invariance, condition-invariance and minimizing training requirements. Here we present an approach that adapts state-of-the-art object proposal techniques to identify potential landmarks within an image for place recognition. We use the astonishing power of convolutional neural network features to identify matching landmark proposals between images to perform place recognition over extreme appearance and viewpoint variations. Our system does not require any form of training, all components are generic enough to be used off-the-shelf. We present a range of challenging experiments in varied viewpoint and environmental conditions. We demonstrate superior performance to current state-of-the- art techniques. Furthermore, by building on existing and widely used recognition frameworks, this approach provides a highly compatible place recognition system with the potential for easy integration of other techniques such as object detection and semantic scene interpretation.
Resumo:
Erythropoietin (EPO), a glycoprotein hormone of ∼34 kDa, is an important hematopoietic growth factor, mainly produced in the kidney and controls the number of red blood cells circulating in the blood stream. Sensitive and rapid recombinant human EPO (rHuEPO) detection tools that improve on the current laborious EPO detection techniques are in high demand for both clinical and sports industry. A sensitive aptamer-functionalized biosensor (aptasensor) has been developed by controlled growth of gold nanostructures (AuNS) over a gold substrate (pAu/AuNS). The aptasensor selectively binds to rHuEPO and, therefore, was used to extract and detect the drug from horse plasma by surface enhanced Raman spectroscopy (SERS). Due to the nanogap separation between the nanostructures, the high population and distribution of hot spots on the pAu/AuNS substrate surface, strong signal enhancement was acquired. By using wide area illumination (WAI) setting for the Raman detection, a low RSD of 4.92% over 150 SERS measurements was achieved. The significant reproducibility of the new biosensor addresses the serious problem of SERS signal inconsistency that hampers the use of the technique in the field. The WAI setting is compatible with handheld Raman devices. Therefore, the new aptasensor can be used for the selective extraction of rHuEPO from biological fluids and subsequently screened with handheld Raman spectrometer for SERS based in-field protein detection.
Resumo:
Sherlock Holmes faces his greatest challenge – since his fight to the death with Professor James Moriarty at Reichenbach Falls. Who owns Sherlock Holmes, the world’s greatest detective? Is it the estate of Sir Arthur Conan Doyle? Or the mysterious socialite Andrea Plunket? Or does Sherlock Holmes belong to the public? This is the question currently being debated in copyright litigation in the United States courts, raising larger questions about copyright law and the public domain, the ownership of literary characters, and the role of sequels, adaptations, and mash-ups.
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There has been an international movement led by 350.org, Bill McKibben, and student groups to encourage schools, universities, and educational institutions to divest their endowments of fossil fuel stocks. The decision of Stanford University on coal divestment should an inspiration for elite universities around the world.
Resumo:
This paper provides a critical examination of the intellectual property sections of the Korea-Australia Free Trade Agreement 2014. Chapter 13 of the Korea-Australia Free Trade Agreement 2014 deals with the subject of intellectual property law. The Chapter covers such topics as the purposes and objectives of intellectual property law; copyright law; trade mark law; patent law; and intellectual property enforcement. The Joint Standing Committee on Treaties in the Australian Parliament highlighted the controversy surrounding this chapter of the agreement: The intellectual property rights chapter of KAFTA has drawn considerable attention from academics and stakeholders regarding the proposed need for changes to Australian intellectual property law and the inclusion of intellectual property in the definition of investment with regard to the investor-state dispute mechanism. Other concerns raised with the Committee include the prescriptive nature of the chapter, the lack of recognition of the broader public interests of intellectual property rights, and possible changes to fair use provisions. Article 13.1.1 of the Korea-Australia Free Trade Agreement 2014 provides that: ‘Each Party recognises the importance of adequate and effective protection of intellectual property rights, while ensuring that measures to enforce those rights do not themselves become barriers to legitimate trade.’ This is an unsatisfactory description of the objectives and purposes of intellectual property law in both Australia and Korea. There is a failure to properly consider the range of public purposes served by intellectual property law – such as providing for access to knowledge, promoting competition and innovation, protecting consumer rights, and allowing for the protection of public health, food security, and the environment. Such a statement of principles and objectives detracts from the declaration in the TRIPS Agreement 1994 of the public interest objectives to be served by intellectual property. Chapter 11 of the Korea-Australia Free Trade Agreement 2014 is an investment chapter, with an investor-state dispute settlement regime. This chapter is highly controversial – given the international debate over investor-state dispute settlement; the Australian context for the debate; and the text of the Korea-Australia Free Trade Agreement 2014. In April 2014, the United Nations Conference on Trade and Development (UNCTAD) released a report on Recent Developments in Investor-State Dispute Settlement. The overall figures are staggering. UNCTAD reports a significant growth in investment-state dispute settlement, across a wide array of different fields of public regulation. Given the broad definition of investment, intellectual property owners will be able to use the investor-state dispute settlement regime in the Korea-Australia Free Trade Agreement 2014. This will have significant implications for all the various disciplines of intellectual property – including copyright law, trade mark law, and patent law.
Resumo:
TThis article considers the radical, sweeping changes to Australian copyright law wrought by the Australia–United States Free Trade Agreement 2004 (AUSFTA). It contends that the agreement will result in a “piracy of the public domain”. Under this new regime, copyright owners will be able to obtain greater monopoly profits at the expense of Australian consumers, libraries and research institutions, as well as intermediaries, such as Internet service providers. Part One observes that the copyright term extension in Australia to life of the author plus 70 years for works will have a negative economic and cultural impact — with Australia’s net royalty payments estimated to be up to $88 million higher per year. Part Two argues that the adoption of stronger protection of technological protection measures modelled upon the Digital Millennium Copyright Act 1998 (U.S.) will override domestic policy–making processes, such as the Phillips Fox Digital Agenda Review, and judicial pronouncements such as the Stevens v Sony litigation. Part Three questions whether the new safe harbours protection for Internet service providers will adversely affect the sale of Telstra. This article concludes that there is a need for judicial restraint in interpreting the AUSFTA. There is an urgent call for the Federal Government to pass ameliorating reforms — such as an open–ended defence of fair use and a mechanism for orphan works. There is a need for caution in negotiating future bilateral trade agreements — lest the multinational system for the protection of copyright law be undermined.