Search results for "bound"
showing 10 items of 2948 documents
Understanding the role of documents in a hierarchical flow of work
1997
Between school and working life: Vocational teachers’ agency in boundary-crossing settings
2009
Abstract This paper investigates agency among vocational teachers with reference to boundary-crossing between school and working life. Our study utilised interviews with sixteen Finnish vocational teachers. Adopting a narrative analysis approach, we found that the teachers had a variety of forms of exercising agency in terms of decisions deliberately taken, and the discourse and actions following these decisions. These forms were: (i) restricted agency, (ii) extensive agency, (iii) multifaceted balancing agency, (iv) situationally diverse agency, and (v) relationally emergent agency. The exercising of agency was intertwined with the main resources and constraints emerging from the teachers’…
The Footprints of a “Mastodon”: How a Decentralized Architecture Influences Online Social Relationships
2019
Decentralized online social networks (DOSNs) have recently emerged as a viable solution to preserve the users' privacy and ensure higher users' control over the contents they publish. However, little is known about the backlashes that the decentralized organization and management of these platforms may have on the overlaid social network. This paper fills the gap. Specifically, we investigate how a decentralized architecture based on distributed servers impacts the structure of the users' neighborhood and their ego-networks. Our analysis relies on social data gathered from the decentralized micro-blogging platform Mastodon, the newest and fastest-growing decentralized alternative to Twitter…
ZnO – Yb2O3 composite optical ceramics: Synthesis, structure and spectral-luminescent properties
2022
International audience; Zinc oxide optical ceramics containing 0 – 2 wt% ytterbium are prepared byuniaxial hot pressing of commercial oxides at 1150 and 1180 °C. The ceramics have themain crystalline phase of hexagonal wurtzite-type ZnO. Ytterbium ions do not enter theZnO crystals but form a cubic sesquioxide phase of Yb2O3 located at the ZnO grainboundaries. Yb acts as an inhibitor for the ZnO grain growth. The ceramics exhibittransmittance up to 60% in the visible. Their transmission in the infrared is determinedby the free charge carrier absorption. The Yb3+ ions are found in C2 and C3i sites in Yb2O3crystals. Under X-ray excitation, the ceramics exhibit intense luminescence bands in the…
Exact constants in Poincaré type inequalities for functions with zero mean boundary traces
2014
In this paper, we investigate Poincare type inequalities for the functions having zero mean value on the whole boundary of a Lipschitz domain or on a measurable part of the boundary. We find exact and easily computable constants in these inequalities for some basic domains (rectangles, cubes, and right triangles) and discuss applications of the inequalities to quantitative analysis of partial differential equations. Copyright © 2014 John Wiley & Sons, Ltd.
Extensions of the witness method to characterize under-, over- and well-constrained geometric constraint systems
2011
International audience; This paper describes new ways to tackle several important problems encountered in geometric constraint solving, in the context of CAD, and which are linked to the handling of under- and over-constrained systems. It presents a powerful decomposition algorithm of such systems. Our methods are based on the witness principle whose theoretical background is recalled in a first step. A method to generate a witness is then explained. We show that having a witness can be used to incrementally detect over-constrainedness and thus to compute a well-constrained boundary system. An algorithm is introduced to check if anchoring a given subset of the coordinates brings the number …
Darboux systems with a cusp point and pseudo-abelian integrals
2018
International audience; We study pseudo-abelian integrals associated with polynomial deformations of Darboux systems having a cuspidal singularity. Under some genericity hypothesis we provide locally uniform boundedness of on the number of their zeros.
Sobolev and bounded variation functions on metric measure spaces
2014
International audience
Categorical action of the extended braid group of affine type $A$
2017
Using a quiver algebra of a cyclic quiver, we construct a faithful categorical action of the extended braid group of affine type A on its bounded homotopy category of finitely generated projective modules. The algebra is trigraded and we identify the trigraded dimensions of the space of morphisms of this category with intersection numbers coming from the topological origin of the group.
On the classification of Kim and Kostrikin manifolds
2006
International audience; We completely classify the topological and geometric structures of some series of closed connected orientable 3-manifolds introduced by Kim and Kostrikin in [20, 21] as quotient spaces of certain polyhedral 3-cells by pairwise identifications of their boundary faces. Then we study further classes of closed orientable 3-manifolds arising from similar polyhedral schemata, and describe their topological properties.