| 21. |
- Clairambault, P., et al.
(author)
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The Biequivalence of Locally Cartesian Closed Categories and Martin-Löf Type Theories
- 2011
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In: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1611-3349 .- 0302-9743. - 9783642216909 ; 6690, s. 91-106
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Conference paper (peer-reviewed)abstract
- Seely's paper Locally cartesian closed categories and type theory contains a well-known result in categorical type theory: that the category of locally cartesian closed categories is equivalent to the category of Martin-Löf type theories with Π, ∑, and extensional identity types. However, Seely's proof relies on the problematic assumption that substitution in types can be interpreted by pullbacks. Here we prove a corrected version of Seely's theorem: that the Bénabou-Hofmann interpretation of Martin-Löf type theory in locally cartesian closed categories yields a biequivalence of 2-categories. To facilitate the technical development we employ categories with families as a substitute for syntactic Martin-Löf type theories. As a second result we prove that if we remove Π-types the resulting categories with families are biequivalent to left exact categories.
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| 22. |
- Clairet, F., et al.
(author)
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Plasma turbulence measured with fast frequency swept reflectometry in JET H-mode plasmas
- 2016
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In: Nuclear Fusion. - : IOP PUBLISHING LTD. - 0029-5515 .- 1741-4326. ; 56:12
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Journal article (peer-reviewed)abstract
- In this work we present recent achievements to provide precise measurements of turbulence on JET H-mode plasmas using frequency sweeping reflectometry diagnostic. The plasma density fluctuations retrieved from swept reflected signals, first initiated with the Tore Supra reflectometry (Heuraux et al 2003 Rev. Sci. Instrum. 74 1501, Vermare et al 2006 Nucl. Fusion 46 S743, Gerbaud et al 2006 Rev. Sci. Instrum. 77 10E928), provides a radial profile of the density fluctuation level and its spectral structure. Using the complete set of the JET X-mode fast sweeping heterodyne reflectometers we have determined the temporal dynamic of the density fluctuation profile from the edge to the center during an H-mode discharge. At the L-H transition, the turbulence reduction seems to occur, at first, simultaneously from the edge to the center then deepens at the edge at rho similar to 0.95 and this deepening propagates toward the center with a steepening of the wavenumber spectra. During an edge localized mode (ELM) event, a substantial density fluctuations increase has been observed with a localized turbulent wave front propagating toward the center accompanying a particle transport. We also show that type-III ELMs sustain a steady and high level of plasma turbulence compare to type-I.
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| 23. |
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| 24. |
- Claisse, Antoine, et al.
(author)
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First-principles calculations of (Y, Ti, O) cluster formation in body centred cubic iron-chromium
- 2013
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In: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 303, s. 18-22
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Journal article (peer-reviewed)abstract
- In the present work, the ab initio parametrization necessary for a Monte Carlo study of the (Y, Ti, O) clusters in a FeCr matrix is done. The cohesive, binding and migration energies of all the solutes have been calculated in the dilute limit in the framework of density functional theory. The special case of the strong interaction between an Y atom and a vacancy has been considered. In the dilute limit, Cr is transparent with respect to Y, Ti, O or vacancies. On the contrary, Y binds O strongly in 2NN configuration while not in 1NN. Ti binds O in 1NN and 2NN configurations. A vacancy binds strongly with Y and O in 1NN position which is resulting in a low diffusion coefficient for Y. The peculiar case of the binding attraction between two interstitial oxygen atoms has been studied and is believed to be the main reason for the planar (2D) symmetry of the cluster nuclei. A preferential cluster shape is determined for the early nucleation stage, up to 12 atoms.
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| 25. |
- Danielsen, Marie, 1955-, et al.
(author)
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Nya studerandegrupper - nya utmaningar
- 2004
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In: Tidskrift för dokumentation. - 0040-6872. ; :3, s. 82-86
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Journal article (pop. science, debate, etc.)
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| 26. |
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| 27. |
- Dunér, David
(author)
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Världsmaskinen. Emanuel Swedenborgs naturfilosofi
- 2004
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Doctoral thesis (other academic/artistic)abstract
- The Swedish natural philosopher Emanuel Swedenborg (1688–1772) thought in his early scientific career that the world was like a gigantic machine, following the laws of mechanics and geometry. The work presented here is a study of his mechanistic worldview and metaphorical way of thinking up to the year 1734, examining most of his fields of interest, from geometry and metaphysics to technology and mining engineering. After that year he left the mechanistic explanations and turned to an organic worldview, and some years later, in 1745, he entered the spiritual world. The study is based on a cognitive view that there are special cognitive abilities, especially metaphorical conceptualization, that cause human beings to think in one way or another. “Space” is an introductory chapter on the concept of space, about his experiences of space gained through optical instruments and his orientation in the intellectual milieu, and of the spatial world with the aid of geometry. “The sign” treats especially some particular sign systems, such as those of arithmetic and algebra, and the classification of the world by categories in number systems, coinage, measures, weights and volumes. “The wave” follows Swedenborg’s use of the metaphor of the wave, not only in such scientific disciplines as hydrology, acoustics, optics and neurology but also in poetry and music. “The sphere” concerns the sphere as the figure of movement, the relationship between technology and science, and analogies, proportions and mental models as important tools for inventing scientific theories, especially in mechanics, physics and chemistry. “The point” has its point of departure in the indivisible point of mathematics. “The spiral” is Swedenborg’s most admired geometrical figure. He wrote about the windings of the spirals in geometry, particle physics, astronomy, and in the nature of the soul. “Infinity” is limited to Swedenborg’s last mechanistic work, De infinito (1734), where he made a strict distinction between the finite and the infinite. “Conclusion” gives an overview of the major themes of his anatomical and physiological studies from the end of the 1730s to 1745, and his spiritual writings to 1772.
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| 28. |
- Faiz, M., et al.
(author)
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Database replica management strategies in multidatabase systems with mobile hosts
- 1996
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In: Database Reengineering and Interoperability. - Berlin : Encyclopedia of Global Archaeology/Springer Verlag. - 030645288X ; , s. 323-336
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Book chapter (other academic/artistic)abstract
- Database systems, wireless communication technologies and advanced applications have given rise to new and challenging problems which have to be dealt with in multidatabase systems (MDS). This paper addresses a classification of various replica control protocols as an integral part of MDS with an emphasis on workstation mobility issues. The paper proposes and discusses modifications that have to be made to replicated database management strategies in order to address the effect of mobility on the existing replica control protocols. In a mobile environment replication will be an essential technique providing reliable distributed computing and data availability to MDS users. It is argued that the existing algorithms have to be tuned for a mobile environment and it is discussed what this may entail. As an illustration, a variation of the primary copy algorithm, called “virtual primary copy” method is proposed and discussed and it is shown that it is well suited for the mobile environment.
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| 29. |
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| 30. |
- Fröjmark, Anders, 1955-
(author)
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The Miracles of St. Bridget and Her Daughter St. Katherine
- 1993
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In: Studies in St. Birgitta and the Brigittine Order 1. - Salzburg : Institut fûr Anglistik und Amerikanistik, Universität Salzburg. - 3705206311 ; , s. 65-84
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Book chapter (other academic/artistic)abstract
- When a person with a reputation for holiness died, it was common for people to seek that person's grave to give thanks for, or hoping to benefit from miraculous cures. Especially when the cult was new, pilgrims' tales were taken down in order to promote the cult or substantiate the request for canonization. The miracles of St. Birgitta of Sweden were collected at various stages between 1374 and 1390 and the writing down of the miracles of her daughter St. Katherine of Vadstena begun shortly after 1410, but was for the major part undertaken between 1469 and 1477.The pilgrimage was often the result of a conditional vow to the saint, sometimes inspired by other persons' stories about the saint's ability to help. Another way of determining which saint to turn to was the casting of lots. In some cases, the miraculous cure might seen to have been brought about by a sort of cooperation between the saint and the persons present, while in other cases the efficacious help of the saint is contrasted to the inefficiency of human efforts. The miracles sometimes exceed the expectations of those who prayed for it, but in other cases it is clear that the healing is only partial. In the few cases where entirely unsuccessful supplications to a saint are described, their only meaning were to direct the supplicant to another saint—the one whose miracles are chiefly registered in the collection.Visions both of the saint and of demons are relatively common in the collections of Birgitta and Katherine. A particularly interesting tale relates the possession of demons experienced by a young woman of Östra Husby in Östergötland, and the efforts made by the clerics of the young monastery in Vadstena to exorcise them. Their success is doubtful. One is rather given the expression that the young woman, Christina, held on to her demons.
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