116 research outputs found

    Drought happens: get used to it! Will technology help us to survive?

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    LectureDrought is not the most popular subject in the world. Actually, as opposed to death, I think there are some bright spots in the drought mitigation future. I will review some of these in this lecture, but I'm also going to discuss some of the downsides of drought, because you can't have one without the other. I do want to focus on technology, but I also want to talk about how people respond to technological advances. Probably some of the more sobering aspects of drought are the severe economic and human impacts that have resulted, particularly in the previous two centuries

    Technical Privacy Metrics: a Systematic Survey

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    The file attached to this record is the author's final peer reviewed versionThe goal of privacy metrics is to measure the degree of privacy enjoyed by users in a system and the amount of protection offered by privacy-enhancing technologies. In this way, privacy metrics contribute to improving user privacy in the digital world. The diversity and complexity of privacy metrics in the literature makes an informed choice of metrics challenging. As a result, instead of using existing metrics, new metrics are proposed frequently, and privacy studies are often incomparable. In this survey we alleviate these problems by structuring the landscape of privacy metrics. To this end, we explain and discuss a selection of over eighty privacy metrics and introduce categorizations based on the aspect of privacy they measure, their required inputs, and the type of data that needs protection. In addition, we present a method on how to choose privacy metrics based on nine questions that help identify the right privacy metrics for a given scenario, and highlight topics where additional work on privacy metrics is needed. Our survey spans multiple privacy domains and can be understood as a general framework for privacy measurement

    Privacy in the Smart City - Applications, Technologies, Challenges and Solutions

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    Many modern cities strive to integrate information technology into every aspect of city life to create so-called smart cities. Smart cities rely on a large number of application areas and technologies to realize complex interactions between citizens, third parties, and city departments. This overwhelming complexity is one reason why holistic privacy protection only rarely enters the picture. A lack of privacy can result in discrimination and social sorting, creating a fundamentally unequal society. To prevent this, we believe that a better understanding of smart cities and their privacy implications is needed. We therefore systematize the application areas, enabling technologies, privacy types, attackers and data sources for the attacks, giving structure to the fuzzy term “smart city”. Based on our taxonomies, we describe existing privacy-enhancing technologies, review the state of the art in real cities around the world, and discuss promising future research directions. Our survey can serve as a reference guide, contributing to the development of privacy-friendly smart cities

    Improving the Accuracy of IVC Simulation using Crowd-sourced Geodata

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    Abstract-We discuss the use of crowd-sourced geodata in simulative evaluations of Inter-Vehicle Communication (IVC) protocol designs. Typically, network simulation tools, which have been improved over decades of network research, are used for evaluating communication systems. In the area of IVC, however, additional challenges have to be met. Most important, the mobility of vehicles in network simulation needs to be represented accurately, e.g., using road traffic microsimulation techniques. These can be integrated with network simulation tools in order to provide a holistic view on the overall system performance. Obviously, the quality of these approaches inherently depends on the quality of provided map data. The OpenStreetMap project provides a community-maintained repository under an open license model. The available crowd-sourced geodata not only consists of road topology data but also includes fine-grained details such as traffic lights, speed limits, and even information about buildings, which represent obstacles for wireless communication. Using our Veins simulation framework, we show that this data increases the accuracy of IVC simulation

    The maximum number of cliques in a graph embedded in a surface

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    This paper studies the following question: Given a surface Σ\Sigma and an integer nn, what is the maximum number of cliques in an nn-vertex graph embeddable in Σ\Sigma? We characterise the extremal graphs for this question, and prove that the answer is between 8(nω)+2ω8(n-\omega)+2^{\omega} and 8n+3/22ω+o(2ω)8n+{3/2} 2^{\omega}+o(2^{\omega}), where ω\omega is the maximum integer such that the complete graph KωK_\omega embeds in Σ\Sigma. For the surfaces S0\mathbb{S}_0, S1\mathbb{S}_1, S2\mathbb{S}_2, N1\mathbb{N}_1, N2\mathbb{N}_2, N3\mathbb{N}_3 and N4\mathbb{N}_4 we establish an exact answer

    Vectorial capacity and vector control: reconsidering sensitivity to parameters for malaria elimination

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    Background: Major gains have been made in reducing malaria transmission in many parts of the world, principally by scaling-up coverage with long-lasting insecticidal nets and indoor residual spraying. Historically, choice of vector control intervention has been largely guided by a parameter sensitivity analysis of George Macdonald's theory of vectorial capacity that suggested prioritizing methods that kill adult mosquitoes. While this advice has been highly successful for transmission suppression, there is a need to revisit these arguments as policymakers in certain areas consider which combinations of interventions are required to eliminate malaria.Methods and Results: Using analytical solutions to updated equations for vectorial capacity we build on previous work to show that, while adult killing methods can be highly effective under many circumstances, other vector control methods are frequently required to fill effective coverage gaps. These can arise due to pre-existing or developing mosquito physiological and behavioral refractoriness but also due to additive changes in the relative importance of different vector species for transmission. Furthermore, the optimal combination of interventions will depend on the operational constraints and costs associated with reaching high coverage levels with each intervention.Conclusions: Reaching specific policy goals, such as elimination, in defined contexts requires increasingly non-generic advice from modelling. Our results emphasize the importance of measuring baseline epidemiology, intervention coverage, vector ecology and program operational constraints in predicting expected outcomes with different combinations of interventions.<br/

    Comparison of the explosion characteristics and flame speeds of pulverised coals and biomass in the ISO standard 1 m3 dust explosion equipment

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    Pulverised coal has been known to pose explosion risks since the 19th century, with the advent of biomass use in coal fired power generation boilers the explosion risk may need revision. The objective of the present work was to compare the explosibility of two samples of bituminous coal used in UK power stations with two biomass fuels and to review available explosion data in the literature for pulverised coal and biomass. The 1 m3 ISO explosion vessel was used to determine the explosion characteristics: deflagration index (KSt), maximum explosion pressure (Pmax) and minimum explosible concentration (MEC). Flame speeds were also measured and these are relevant to understanding the mechanism of turbulent flame propagation in power station burners, which is related to the problem of flame flashback or blow-off. Despite the similarities in composition of both coals, the explosion reactivity of Colombian coal was much higher, with a KSt value of 129 bar m/s compared to 78 bar m/s for Kellingley coal. The main difference between the two fuels was the surface area of particles which was higher for Colombian coal. It was shown that the char burn out rate at 900 °C in air was higher for Colombian coal, due to the greater oxygen diffusion in the higher porosity of the char. Results for two biomass fuels are also presented with similar values for KSt and the literature review shows that both coal and biomass have very variable flame reactivities. There is no general trend that coal is less reactive than biomass, although this could be the case for specific coals and biomass

    Pareto rules for malaria super-spreaders and super-spreading

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    Heterogeneity in transmission is a challenge for infectious disease dynamics and control. An 80-20 “Pareto” rule has been proposed to describe this heterogeneity whereby 80% of transmission is accounted for by 20% of individuals, herein called super-spreaders. It is unclear, however, whether super-spreading can be attributed to certain individuals or whether it is an unpredictable and unavoidable feature of epidemics. Here, we investigate heterogeneous malaria transmission at three sites in Uganda and find that super-spreading is negatively correlated with overall malaria transmission intensity. Mosquito biting among humans is 90-10 at the lowest transmission intensities declining to less than 70-30 at the highest intensities. For super-spreaders, biting ranges from 70-30 down to 60-40. The difference, approximately half the total variance, is due to environmental stochasticity. Super-spreading is thus partly due to super-spreaders, but modest gains are expected from targeting super-spreaders
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