5,379 research outputs found
When is Galois cohomology free or trivial?
Let p be a prime and F a field containing a primitive pth root of unity. Let
E/F be a cyclic extension of degree p and G_E < G_F the associated absolute
Galois groups. We determine precise conditions for the cohomology group
H^n(E)=H^n(G_E,Fp) to be free or trivial as an Fp[Gal(E/F)]-module. We examine
when these properties for H^n(E) are inherited by H^k(E), k>n, and, by analogy
with cohomological dimension, we introduce notions of cohomological freeness
and cohomological triviality. We give examples of H^n(E) free or trivial for
each n in N with prescribed cohomological dimension.Comment: 29 pages; removed hypothesis on perfect fields in main results, and
added reference
On Az\'ema-Yor processes, their optimal properties and the Bachelier-drawdown equation
We study the class of Az\'ema-Yor processes defined from a general
semimartingale with a continuous running maximum process. We show that they
arise as unique strong solutions of the Bachelier stochastic differential
equation which we prove is equivalent to the drawdown equation. Solutions of
the latter have the drawdown property: they always stay above a given function
of their past maximum. We then show that any process which satisfies the
drawdown property is in fact an Az\'ema-Yor process. The proofs exploit group
structure of the set of Az\'ema-Yor processes, indexed by functions, which we
introduce. We investigate in detail Az\'ema-Yor martingales defined from a
nonnegative local martingale converging to zero at infinity. We establish
relations between average value at risk, drawdown function, Hardy-Littlewood
transform and its inverse. In particular, we construct Az\'ema-Yor martingales
with a given terminal law and this allows us to rediscover the Az\'ema-Yor
solution to the Skorokhod embedding problem. Finally, we characterize
Az\'ema-Yor martingales showing they are optimal relative to the concave
ordering of terminal variables among martingales whose maximum dominates
stochastically a given benchmark.Comment: Published in at http://dx.doi.org/10.1214/10-AOP614 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Galois module structure of Galois cohomology for embeddable cyclic extensions of degree p^n
Let p>2 be prime, and let n,m be positive integers. For cyclic field
extensions E/F of degree p^n that contain a primitive pth root of unity, we
show that the associated F_p[Gal(E/F)]-modules H^m(G_E,mu_p) have a sparse
decomposition. When E/F is additionally a subextension of a cyclic, degree
p^{n+1} extension E'/F, we give a more refined F_p[Gal(E/F)]-decomposition of
H^m(G_E,mu_p)
Conditioned by Dress – The Relationship between Mind, Fashion, Film & Performance.
This is the first monograph in the Pocket Book Series Practices of Transdisciplinarity, a co-publishing collaboration between the ArtEZ Academy in the Netherlands and the London College of Fashion. 'Practices of Transdisciplinarity' examines creative research practices that cross the traditional boundaries assigned to art and design disciplines.
Anna-Nicole Ziesche's: Conditioned by Dress - The Relationship between Mind, Fashion, Film and Performance' opens the series.
This combined visual and text-based publication is the first book to present an overview of Anna-Nicole Ziesche’s films. Her early work investigates methods for composing fashion ‘looks’, using simple film editing techniques to manipulate, magnify and repeat the decorative details of cloth onto the body. We discover her unique research process that uses story telling and performance to explore the relationship between self-perception and dress. Anna-Nicole is also a sculptor; she re-constructs her dreams, building installations in which she subjects the body to poetic narratives inspired by her experiences of fashion. Within these installations Anna-Nicole and her ‘dressed’ characters perform both physically and psychologically. Film and photography are mediums where "to dress" takes on a new meaning.
[from the Foreword, by Lucy Orta
Small scale assessment of copepod epibionts with the Lightframe On-sight Keyspecies Investigation system (LOKI) in the Norwegian Sognefjord
During an expedition with RV Heincke in October/November 2014 twelve stations in the Norwegian Sognefjord were sampled with the Lightframe On-sight Keyspecies Investigation system (LOKI, Schulz et al. 2010). This optical sampling device allows merging of high quality in-situ image data of individual specimens with ambient environmental parameters on scales of a few centimetres. Investigating raw data for species distribution patterns it became obvious, that epibiont carrying copepods are related to specific water properties in the trough and behind the sill at the entrance of the fjord. Here we give a first peek about small scale relationships between hydrography and interactions of biota, insufficiently detectable with classical net samplings
Understanding Worker Participation and Organizational Performance at the Firm Level: In Search for an Integrated Model
Last decades scholars in the field of human resource management (HRM) have intensely examined the contribution of HRM to organizational performance. Despite their efforts, at least one major research shortcoming can be identified. In general, they have devoted far too little attention to an aspect of HRM potentially beneficial for organizational performance: worker participation, and especially its indirect or representative forms. In contrast, for academics embedded in the industrial relations tradition, worker participation is a prominent theme, even though less emphasized in its relationship with company objectives. One might defend traditional scholars' reservations by arguing that participations main goal concerns workplace democratization and not organizational prosperity. However, several writers state that industrial democracy involving worker participation can channel conflicts of interest between employees and employers and stimulate desired employee attitudes and behavior, consequently enhancing organizational performance (e.g., Gollan, 2006; Ramsay, 1991; Taras & Kaufman, 1999). And, indeed, several studies have shown positive effects of both direct participation (e.g., European Foundation for the Improvement of Living and Working Conditions, 1997) and indirect participation (e.g., Addison et al., 2000, 2003; Frick & Möller, 2003) on organizational performance.\ud
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Nevertheless, to date, the absence of an integrated model explaining the connection between worker participation and organizational performance leads to the following question that still is in need of an answer: how do direct and indirect forms of participation – separate as well as in combination – affect organizational performance? This chapter aims to contribute to the filling of the aforementioned knowledge gaps. In so doing, we focus on direct and indirect, nonunion participation on the firm level, using a Western European and especially Dutch frame of reference\u
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