122,531 research outputs found
Phase space reduction of star products on cotangent bundles
No full textIn this paper we construct star products on Marsden-Weinstein reduced
spaces in case both the original phase space and the reduced phase space are (symplectomorphic
to) cotangent bundles. Under the assumption that the original cotangent
bundle T∗Q carries a symplectic structure of form ωB0 = ω0 +π∗B0 with B0
a closed two-form on Q, is equipped by the cotangent lift of a proper and free Lie
group action on Q and by an invariant star product that admits a G-equivariant
quantum momentum map, we show that the reduced phase space inherits from
T∗Q a star product. Moreover, we provide a concrete description of the resulting
star product in terms of the initial star product on T∗Q and prove that our
reduction scheme is independent of the characteristic class of the initial star product.
Unlike other existing reduction schemes we are thus able to reduce not only
strongly invariant star products. Furthermore in this article, we establish a relation
between the characteristic class of the original star product and the characteristic
class of the reduced star product and provide a classification up to G-equivalence
of those star products on (T∗Q, ωB0 ), which are invariant with respect to a lifted
Lie group action. Finally, we investigate the question under which circumstances
‘quantization commutes with reduction’ and show that in our examples non-trivial
restrictions arise
A note on the SSOR convergence domain due to Neumaier and Varga
No full textAbstractIn a recent paper A. Neumaier and R. S. Varga show that if A is an n ×ncomplex H-matrix with 12 < ϱ(∣JA∣) < 1, then ϱ(SAω) < 1 for all 0 < ω < g̃w:=2/ (1 + √2ϱ(∣JA∣) − 1), where SAω and JA are, respectively, the symmetric successive overrelaxation (SSOR) iteration matrix and the Jacobi iteration matrix associated with A. We show that ϱ(SAg̃w) < 1. This allows us to also sharpen further results on the SSOR method for H-matrices due to Varga, Niethammer, and Cai
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Calcific tendinitis of the rotator cuff as a cause of drooping shoulder
No full textWe describe a case of inferior glenohumeral subluxation or drooping shoulder secondary to acute calcific tendinitis of the rotator cuff. The various etiologies of drooping shoulder and the specific causes determining glenohumeral widening in our report are discussed. The importance in recognizing this uncommon complication of a common abnormal finding and correction by aspiration is stressed
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Current Saturation and Voltage Gain in Bilayer Graphene Field Effect Transistors
No full texthttp://www.gianlucafiori.org/articles/nl2012.pd
Velocity saturation in few-layer MoS2 transistor
No full texthttp://www.gianlucafiori.org/articles/fiori_MoS2.pd
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
No full textDifferently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
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