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Weak approximation of a fractional SDE ; Nourdin, Ivan ; et al in Stochastic Processes & Their Applications (2010), 120 Detailed reference viewed: 56 (3 UL)Weak convergence to Ocone martingales: a remark Peccati, Giovanni in Electronic Communications in Probability (2004), 9 Detailed reference viewed: 76 (0 UL)Weak fiber products in bicategories of fractions Tommasini, Matteo E-print/Working paper (2014) We fix any pair (C,W) consisting of a bicategory and a class of morphisms in it, admitting a bicalculus of fractions, i.e. a “localization” of C with respect to the class W. In the resulting bicategory of ... [more ▼] We fix any pair (C,W) consisting of a bicategory and a class of morphisms in it, admitting a bicalculus of fractions, i.e. a “localization” of C with respect to the class W. In the resulting bicategory of fractions, we identify necessary and sufficient conditions for the existence of weak fiber products. [less ▲] Detailed reference viewed: 19 (1 UL)Weak Interference Detection with Signal Cancellation in Satellite Communications Politis, Christos ; Maleki, Sina ; Tsinos, Christos et al in The 42nd IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 2017 (2017) Interference is identified as a critical issue for satellite communication (SATCOM) systems and services. There is a growing concern in the satellite industry to manage and mitigate interference ... [more ▼] Interference is identified as a critical issue for satellite communication (SATCOM) systems and services. There is a growing concern in the satellite industry to manage and mitigate interference efficiently. While there are efficient techniques to monitor strong interference in SATCOM, weak interference is not so easily detected because of its low interference to signal and noise ratio (ISNR). To address this issue, this paper proposes and develops a technique which takes place on-board the satellite by decoding the desired signal, removing it from the total received signal and applying an Energy Detector (ED) in the remaining signal for the detection of interference. Different from the existing literature, this paper considers imperfect signal cancellation, examining how the decoding errors affect the sensing performance, derives the expressions for the probability of false alarm and provides a set of simulations results, verifying the efficiency of the technique. [less ▲] Detailed reference viewed: 260 (34 UL)Weak Iron Oxidation by Sulfobacillus thermosulfidooxidans Maintains a Favorable Redox Potential for Chalcopyrite Bioleaching ; Herold, Malte ; et al in Frontiers in Microbiology (2018), 9(December), 1-12 Bioleaching is an emerging technology, describing the microbially assisted dissolution of sulfidic ores that provides a more environmentally friendly alternative to many traditional metal extraction ... [more ▼] Bioleaching is an emerging technology, describing the microbially assisted dissolution of sulfidic ores that provides a more environmentally friendly alternative to many traditional metal extraction methods, such as roasting or smelting. Industrial interest is steadily increasing and today, circa 15–20% of the world’s copper production can be traced back to this method. However, bioleaching of the world’s most abundant copper mineral chalcopyrite suffers from low dissolution rates, often attributed to passivating layers, which need to be overcome to use this technology to its full potential. To prevent these passivating layers from forming, leaching needs to occur at a low oxidation/reduction potential (ORP), but chemical redox control in bioleaching heaps is difficult and costly. As an alternative, selected weak iron-oxidizers could be employed that are incapable of scavenging exceedingly low concentrations of iron and therefore, raise the ORP just above the onset of bioleaching, but not high enough to allow for the occurrence of passivation. In this study, we report that microbial iron oxidation by Sulfobacillus thermosulfidooxidans meets these specifications. Chalcopyrite concentrate bioleaching experiments with S. thermosulfidooxidans as the sole iron oxidizer exhibited significantly lower redox potentials and higher release of copper compared to communities containing the strong iron oxidizer Leptospirillum ferriphilum. Transcriptomic response to single and co-culture of these two iron oxidizers was studied and revealed a greatly decreased number of mRNA transcripts ascribed to iron oxidation in S. thermosulfidooxidans when cultured in the presence of L. ferriphilum. This allowed for the identification of genes potentially responsible for S. thermosulfidooxidans’ weaker iron oxidation to be studied in the future, as well as underlined the need for new mechanisms to control the microbial population in bioleaching heaps. [less ▲] Detailed reference viewed: 51 (7 UL)Weak poincaré inequality for convolution probability measures Cheng, Li Juan ; E-print/Working paper (2016) In this article, weak Poincaré inequalities are established for convolution measures by using Lyapunov conditions. As applications, these results are further applied to some explicit cases. Detailed reference viewed: 64 (12 UL)The weak Stratonovich integral with respect to fractional Brownian motion with Hurst parameter H=1/6 Nourdin, Ivan ; ; in Electronic Journal of Probability (2010), 15 Detailed reference viewed: 44 (3 UL)Weak symmetric integrals with respect to the fractional Brownian motion ; Nourdin, Ivan ; in Annals of Probability (2018), 46(4), 2243-2267 Detailed reference viewed: 153 (2 UL)Weakening the tight coupling between geometry and simulation in isogeometric analysis Tomar, Satyendra ; ; et al Presentation (2016, June 07) In the standard paradigm of isogeometric analysis, the geometry and the simulation spaces are tightly integrated, i.e. the same non-uniform rational B-splines (NURBS) space, which is used for the geometry ... [more ▼] In the standard paradigm of isogeometric analysis, the geometry and the simulation spaces are tightly integrated, i.e. the same non-uniform rational B-splines (NURBS) space, which is used for the geometry representation of the domain, is employed for the numerical solution of the problem over the domain. However, there are situations where this tight integration is a bane rather than a boon. Such situations arise where, e.g., (1) the geometry of the domain is simple enough to be represented by low order NURBS, whereas the unknown (exact) solution of the problem is sufficiently regular, and thus, the numerical solution can be obtained with improved accuracy by using NURBS of order higher than that required for the geometry, (2) the constraint of using the same space for the geometry and the numerical solution is particularly undesirable, such as in the shape and topology optimization, and (3) the solution of the problem has low regularity but for the curved boundary of the domain one can employ higher order NURBS. Therefore, we propose to weaken this constraint. An extensive study of patch tests on various combinations of polynomial degree, geometry type, and various cases of varying degrees and control variables between the geometry and the numerical solution will be discussed. It will be shown, with concrete reasoning, that why patch test fails in certain cases, and that those cases should be avoided in practice. Thereafter, selective numerical examples will be presented to address some of the above-mentioned situations, and it will be shown that weakening the tight coupling between geometry and simulation offers more flexibility in choosing the numerical solution spaces, and thus, improved accuracy of the numerical solution. [less ▲] Detailed reference viewed: 145 (9 UL)Weakening the tight coupling between geometry and simulation in isogeometric analysis Bordas, Stéphane ; Tomar, Satyendra ; et al Scientific Conference (2016, June 05) In the standard paradigm of isogeometric analysis, the geometry and the simulation spaces are tightly integrated, i.e. the same non-uniform rational B-splines (NURBS) space, which is used for the geometry ... [more ▼] In the standard paradigm of isogeometric analysis, the geometry and the simulation spaces are tightly integrated, i.e. the same non-uniform rational B-splines (NURBS) space, which is used for the geometry representation of the domain, is employed for the numerical solution of the problem over the domain. However, there are situations where this tight integration is a bane rather than a boon. Such situations arise where, e.g., (1) the geometry of the domain is simple enough to be represented by low order NURBS, whereas the unknown (exact) solution of the problem is sufficiently regular, and thus, the numerical solution can be obtained with improved accuracy by using NURBS of order higher than that required for the geometry, (2) the constraint of using the same space for the geometry and the numerical solution is particularly undesirable, such as in the shape and topology optimization, and (3) the solution of the problem has low regularity but for the curved boundary of the domain one can employ higher order NURBS. Therefore, we propose to weaken this constraint. An extensive study of patch tests on various combinations of polynomial degree, geometry type, and various cases of varying degrees and control variables between the geometry and the numerical solution will be discussed. It will be shown, with concrete reasoning, that why patch test fails in certain cases, and that those cases should be avoided in practice. Thereafter, selective numerical examples will be presented to address some of the above-mentioned situations, and it will be shown that weakening the tight coupling between geometry and simulation offers more flexibility in choosing the numerical solution spaces, and thus, improved accuracy of the numerical solution. Powered by [less ▲] Detailed reference viewed: 126 (5 UL)Weakening the tight coupling between geometry and simulation in isogeometric analysis: from sub- and super- geometric analysis to Geometry Independent Field approximaTion (GIFT) ; Tomar, Satyendra ; et al in International Journal for Numerical Methods in Engineering (2018) This paper presents an approach to generalize the concept of isogeometric analysis (IGA) by allowing different spaces for parameterization of the computational domain and for approximation of the solution ... [more ▼] This paper presents an approach to generalize the concept of isogeometric analysis (IGA) by allowing different spaces for parameterization of the computational domain and for approximation of the solution field. The method inherits the main advantage of isogeometric analysis, i.e. preserves the original, exact CAD geometry (for example, given by NURBS), but allows pairing it with an approximation space which is more suitable/flexible for analysis, for example, T-splines, LR-splines, (truncated) hierarchical B-splines, and PHT-splines. This generalization offers the advantage of adaptive local refinement without the need to re-parameterize the domain, and therefore without weakening the link with the CAD model. We demonstrate the use of the method with different choices of the geometry and field splines, and show that, despite the failure of the standard patch test, the optimum convergence rate is achieved for non-nested spaces. [less ▲] Detailed reference viewed: 163 (8 UL)Weakening the tight coupling between geometry and simulation in isogeometric analysis: from sub- and super- geometric analysis to Geometry Independent Field approximaTion (GIFT) ; ; Tomar, Satyendra et al E-print/Working paper (n.d.) This paper presents an approach to generalize the concept of isogeometric analysis (IGA) by allowing different spaces for parameterization of the computational domain and for approximation of the solution ... [more ▼] This paper presents an approach to generalize the concept of isogeometric analysis (IGA) by allowing different spaces for parameterization of the computational domain and for approximation of the solution field. The method inherits the main advantage of isogeometric analysis, i.e. preserves the original, exact CAD geometry (for example, given by NURBS), but allows pairing it with an approximation space which is more suitable/flexible for analysis, for example, T-splines, LR-splines, (truncated) hierarchical B-splines, and PHT-splines. This generalization offers the advantage of adaptive local refinement without the need to re-parameterize the domain, and therefore without weakening the link with the CAD model. We demonstrate the use of the method with different choices of the geometry and field splines, and show that, despite the failure of the standard patch test, the optimum convergence rate is achieved for non-nested spaces. [less ▲] Detailed reference viewed: 226 (13 UL)Weakly Inscribed Polyhedra ; Schlenker, Jean-Marc E-print/Working paper (2017) Detailed reference viewed: 28 (1 UL)Wealth accumulation over the life course. The role of disadvantages across the employment history Ponomarenko, Valentina E-print/Working paper (2017) In this study wealth is employed as an often neglected but highly stratified well-being measure in sociology. I relate the employment history and especially the accumulating disadvantages like ... [more ▼] In this study wealth is employed as an often neglected but highly stratified well-being measure in sociology. I relate the employment history and especially the accumulating disadvantages like nonemployment and lower occupations to wealth in old age. In particular, I am interested in determining whether an adverse employment history prevents wealth accumulation and which factors influence wealth accumulation across the life course. I use comparative data from the Survey of Health, Ageing and Retirement and combine it with the retrospective panel SHARELIFE to retrieve information about the complete employment history. The relevance of wealth varies significantly across households and in the wider national context. Hence, a contextual perspective is included to account for the difference in wealth rates and wealth inequality in the European countries. The results show that cumulative nonemployment and employment in lower occupations has significant disadvantages for wealth accumulation in old age. However, large differences for men and women persist. Particularly, the household composition and household factors are decisive in the effectuality of these disadvantages. The relation of life course employment and especially disadvantages to accumulated wealth in old aged is stronger in conservative countries than in other welfare regimes. [less ▲] Detailed reference viewed: 286 (7 UL)Wealth Inequality ; ; Van Kerm, Philippe in Nolan, Brian (Ed.) Generating Prosperity for Working Families in Affluent Countries (2018) Detailed reference viewed: 28 (2 UL)Wealth inequality, frailty, and memory impairment: Is wealthier = healthier true at all older ages? Leist, Anja Scientific Conference (2018, December) Detailed reference viewed: 43 (2 UL)Wealth Inequality: A Survey ; Van Kerm, Philippe in Journal of Economic Surveys (2015), 29(4), 671-710 We survey the issues involved in comparing wealth distributions and measuring wealth inequality with illustrations from the Eurosystem Household Finance and Consumption Survey. Detailed reference viewed: 91 (2 UL)Wealth, Top Incomes, and Inequality ; ; et al in Hamilton, Kirk; Hepburn, Cameron (Eds.) National Wealth: What is Missing, Why it Matters (2017) Although it is heartening to see wealth inequality being taken seriously, key concepts are often muddled, including the distinction between income and wealth, what is included in "wealth", and facts about ... [more ▼] Although it is heartening to see wealth inequality being taken seriously, key concepts are often muddled, including the distinction between income and wealth, what is included in "wealth", and facts about wealth distributions. This chapter highlights issues that arise in making ideas and facts about wealth inequality precise, and employs newly-available data to take a fresh look at wealth and wealth inequality in a comparative perspective. The composition of wealth is similar across countries, with housing wealth being the key asset. Wealth is considerably more unequally distributed than income, and it is distinctively so in the United States. Extending definitions to include pension wealth however reduces inequality substantially. Analysis also sheds light on life-cycle patterns and the role of inheritance. Discussion of the joint distributions of income and wealth suggests that interactions between increasing top income shares and the concentration of wealth and income from wealth towards the top is critical. [less ▲] Detailed reference viewed: 47 (7 UL)A Wearable Revolution: Is the smartwatch the next small big thing? Kracheel, Martin ; Bronzi, Walter ; Article for general public (2014) Smartwatches have the potential to enhance our digital lifestyle, but are not yet a part of our digital lifestyle. When big competitors overcome smartwatches usability challenges and design limitations ... [more ▼] Smartwatches have the potential to enhance our digital lifestyle, but are not yet a part of our digital lifestyle. When big competitors overcome smartwatches usability challenges and design limitations, this could change rapidly. The smartwatch, to be successful, has to combine two requirements: provide digital information and individual expression presented by traditional watches. The smartwatch can excel in a new category of "smart" devices to be used instead of our smartphones for simplifying and speeding up activities such as reading a message, checking the weather, traffic directions or your agenda. The support from the community of developers will play a major role in deciding which platform will progress further. [less ▲] Detailed reference viewed: 1359 (9 UL)Weaving Rules into Models@run.time for Embedded Smart Systems Mouline, Ludovic ; Hartmann, Thomas ; Fouquet, François et al in Mouline, Ludovic; Hartmann, Thomas; Fouquet, François (Eds.) et al Programming '17 Companion to the first International Conference on the Art, Science and Engineering of Programming (2017, April) Smart systems are characterised by their ability to analyse measured data in live and to react to changes according to expert rules. Therefore, such systems exploit appropriate data models together with ... [more ▼] Smart systems are characterised by their ability to analyse measured data in live and to react to changes according to expert rules. Therefore, such systems exploit appropriate data models together with actions, triggered by domain-related conditions. The challenge at hand is that smart systems usually need to process thousands of updates to detect which rules need to be triggered, often even on restricted hardware like a Raspberry Pi. Despite various approaches have been investigated to efficiently check conditions on data models, they either assume to fit into main memory or rely on high latency persistence storage systems that severely damage the reactivity of smart systems. To tackle this challenge, we propose a novel composition process, which weaves executable rules into a data model with lazy loading abilities. We quantitatively show, on a smart building case study, that our approach can handle, at low latency, big sets of rules on top of large-scale data models on restricted hardware. [less ▲] Detailed reference viewed: 211 (21 UL) |
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