11,501 research outputs found
Moving the Weber fraction: the perceptual precision for moment of inertia increases with exploration force
No full textHow does the magnitude of the exploration force influence the precision of haptic perceptual estimates? To address this question, we examined the perceptual precision for moment of inertia (i.e., an object’s ‘‘angular mass’’) under different force conditions, using the Weber fraction to quantify perceptual precision. Participants rotated a rod around a fixed axis and judged its moment of inertia in a two-alternative forced-choice task. We instructed different levels of exploration force, thereby manipulating the magnitude of both the exploration force and the angular acceleration. These are the two signals that are needed by the nervous system to estimate moment of inertia. Importantly, one can assume that the absolute noise on both signals increases with an increase in the signals’ magnitudes, while the relative noise (i.e., noise/signal) decreases with an increase in signal magnitude. We examined how the perceptual precision for moment of inertia was affected by this neural noise. In a first experiment we found that a low exploration force caused a higher Weber fraction (22%) than a high exploration force (13%), which suggested that the perceptual precision was constrained by the relative noise. This hypothesis was supported by the result of a second experiment, in which we found that the relationship between exploration force and Weber fraction had a similar shape as the theoretical relationship between signal magnitude and relative noise. The present study thus demonstrated that the amount of force used to explore an object can profoundly influence the precision by which its properties are perceived
Workshop report. Linear-Scaling Ab Initio Calculations: Applications and Future Directions
No full textThe study of properties and of processes in materials, frequently hinges upon understanding phenomena which originate at the atomic level. In such cases the accurate description of the interactions between large numbers of atoms is critical and in turn requires the accurate description of the electrons which play a crucial role in the bonding of atoms into molecules, surfaces and solids. This can only be achieved by solving the equations of quantum mechanics. These
equations are too complicated to solve exactly; however their solutions can be approximated by computational techniques. The most accurate ? but also most computationally demanding ? are the “ab initio” techniques which do not use any empirical adjustable parameters. Amongst them, the Density Functional Theory (DFT) formulation of quantum mechanics stands out as an excellent compromise between accuracy and computational efficiency. However, the applicability of ab initio techniques is severely limited by poor scaling: the computational effort needed to perform an ab initio calculation increases with (at least) the third power of the number of atoms, N. This cubic-scaling bottleneck limits the number of atoms we can study to a few hundred at most, even on parallel supercomputers. To overcome this length-scale limitation, a number of researchers worldwide have been pioneering the development of a novel class of ab initio methods with linear-scaling or “Order N” (O(N)) computational cost which nevertheless retain the same high level of accuracy as the conventional approaches. While physically motivated, such methods have proved particularly hard to develop as they introduce highly non-trivial localisation constraints. Nevertheless, many major obstacles have been overcome and a number of O(N)
methods (SIESTA, CONQUEST, ONETEP, etc.) for ground state DFT calculations on systems with a gap (e.g. molecules, semiconductors and insulators) are now available and have reached a state of maturity that allows them to be used to study ”real” materials. The particular focus of this workshop is therefore to look forward to what can be achieved in the next few years. Our aim is twofold: (1) As O(N) methods are currently extending the applicability of DFT calculations
to problems involving biomolecules and nanostructures they are leading to completely new levels of understanding of these systems. This CECAM meeting will give us the opportunity to make an appraisal of such large-scale simulations and their potential to connect more directly to experiments. (2) We also want to examine the options for extending linear-scaling to problems that cannot be treated by ground-state DFT but require other, more complex approaches. These include methods for treating metallic systems, excited states and wavefunction-based theories for including electronic correlation. Finding ways to transform these methods to linear-scaling
cost, and hence extent their applicability to the nano-scale, is the next big challenge that the community of developers of large-scale electronic structure methods is beginning to face. We
hope that this workshop will stimulate these major new O(N) methodological developments by bringing together the leading groups in the development of O(N) DFT methods with the leading
groups in the development of metal and excited-state or wavefunction-based methods. Strong emphasis during the workshop will be given to discussion in order to promote the exchange
of ideas between different communities (Physics, Chemistry, Materials Science, Biochemistry) which are all interested in large-scale applications with ab initio accuracy but are approaching
them from different perspectives
Ab ins Ausland! Sommerkurse und weitere Angebote an den Instituten der Max Weber Stiftung
No full textDu möchtest Geisteswissenschaften aus einer anderen Perspektive erleben und erfahren wie und woran im Ausland geforscht wird? Möchtest du deine Forschungsergebnisse mit anderen WissenschaftlerInnen teilen und deine Fremdsprachenkenntnisse verbessern? Für junge (Nachwuchs-) GeisteswissenschaftlerInnen organisieren die Auslandsinstitute der Max Weber Stiftung jährlich für den Sommer und den Herbst eine Reihe von Studienkursen, die dir einen Einblick in ein neues wissenschaftliches Umfeld und e..
Ab in die Praxis! (Wissenschaftliche) Praktika in der Max Weber Stiftung
No full textDu bist mitten im Studium und suchst nach ersten praktischen Erfahrungen in einer wissenschaftlichen Institution? Oder stehst du bereits kurz vor der Promotion und suchst nach einer Tätigkeit, die für deine eigene wissenschaftliche Arbeit hilfreich ist? Für deutsche Studierende der Geisteswissenschaften und benachbarter Fächer bieten die Institute der Max Weber Stiftung sowie die Geschäftsstelle in Bonn mehrere Praktikumsplätze in verschiedenen Tätigkeitsfeldern. Bei einem Praktikum in ein..
cana
No full textPackera cana (Hooker) W.A. Weber & Á. Lövewoolly groundselséneçon blanchâtre3 km W of Lindberg, AB. turnoff Twp. 564aJoanne Golden303 m as
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Murray City Firemen
No full textMurray firemen with truck in front of Murray Fire Station. The man not in uniform is unidentified. Axel Limberg, Ernest Smith, Bill Ringrose, AB Caldwell. Courtesy of Judy Weber
The End of a Solitary Phenomenon? The Literature about Max Weber 1920-1988
No full textMax Weber und sein Werk, so wird behauptet, erlebe heute wieder eine Art Renaissance, und zwar in dem Maße, daß sich die Weber-Literatur seit 1976 verdoppelt hätte. 1976 wurde eine Weber-Bibliographie herausgegeben, in der ungefähr 2400 Artikel und Bücher über Weber vorkamen, publiziert in der Periode 1920-1976. Aufgrund der genannten Bibliogaphie wird gezeigt, in welchen Sprachen Weber-Artikel und -Bücher publiziert wurden, welche Fluktationen in der Weber-Literatur auftreten seit 1920, welche Themen aus Webers Werk insbesondere in bestimmten Perioden behandelt wurden und welche Erklärungen für das Interesse an diesen Themen gegeben werden können. Es stellt sich heraus, daß diese Weber-Literatur ab 1976 nicht nur keine Verdoppelung erfuhr, sondern daß sich ab ungefähr 1973 ein definitiver und jedenfalls ein sehr scharfer Niedergang dieser Literatur eingesetzt hat.
cana
No full textPackera cana (Hooker) W.A. Weber & Á. Lövewoolly groundselséneçon blanchâtreGrizzly Bear Creek, AB., Legal land location 3 - 29 - 48 - 5 - W4, south of Hwy 619Joanne Goldeneast bank of coulee north side of roadoil lease id 66 - 567 - 568 - 56
cana
No full textPackera cana (Hooker) W.A. Weber & Á. Lövewoolly groundselséneçon blanchâtrebadlands 2 km E of Donald, AB. turnoffJoanne GoldenS-facing slpe on west side of coulee on Hwy. 53with kinninkinick727 m as
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