744,509 research outputs found
Reconciling structure and agency in strategy -as-practice research: Towards a strong- structuration theory approach
An overwhelming focus of research on the micro agency of strategic actors has led to the literature being characterized as demonstrating a micro-myopia, resulting in a micro-isolationism. This means we know little about how the micro interrelates with the macro in strategy work. We address this problem in our conceptual article which adopts a structurationist stance to explicate how strategy-as-practice (SaP) research could be enhanced and extended by paying equal attention to both agency and structure. Specifically, we advance strong structuration theory (SST), a promising development from Giddensâ seminal work on structuration theory, to show how strategic activity can be understood as an ongoing process of structuration unfolding over time. We argue for the use of both types of methodological bracketing (context and conduct analysis), advocating systematic attention to the interplay between macro-societal and micro-local levels of analysis. Our discussion concludes with guidance for researchers inviting them to undertake empirical fieldwork that overcomes SaPâs current micro-myopia, creating a more balanced corpus of work
Do interactions between plant roots and the rhizosphere affect parasitoid behaviour?
Multitrophic interactions are powerful forces shaping the structure of living communities. Plants encounter a great diversity of organisms in their environment: some of these interactions are beneficial (e.g. symbiotic fungi and insect pollinators) while some are detrimental (e.g. herbivorous insects and pathogenic micro-organisms). Multitrophic interactions between below-ground and above-ground organisms are receiving increasing attention because they may influence plant defences against biotic and abiotic stresses. In this study we show that an arbuscular mycorrhizal symbiosis makes tomato plants significantly more resistant towards aphids, by enhancing both direct defences, both attractivity towards aphid parasitoids
Rethinking Trust, Crime Policy and Social Theory,
This article analyses the relationship of âtrustâ to crime, power and criminal justice policy. The theoretical model employed to analyse this relationship draws from Owenâs (2009a), conceptually driven argument that is based on an ontologically-flexible critique of agency-structure, micro-macro and time-space. This relationship stands at the interface of competing pressures working to produce the increasing complexity of crime and criminal justice policy (Powell 2005). We then move the attention to the conceptual problems of âtrustâ which is linked with uncertainty and complexity whilst law and order and crime policies rest on the specialist knowledge claimed by a range of professional âexpertsâ and technologists that inhabit powerful spaces through which crime policy and practice is governed and articulated
A critical analysis of multilingual dictionaries
This article evaluates the lexicographic value of multilingual dictionaries. Dictionaries covering three or more languages spoken in South Africa are taken as a case in point. An attempt will be made to reflect on their merits and shortcomings as reference works and learning tools but the focus will be on presumed shortcomings in the macro and micro structures of such dictionaries with special attention to the lemmatisation of common words, quality of the dictionary articles and consistency in presentation.Keywords: Multilingual dictionaries, Macro structure, Micro structure, African languages, Thematic ordering, Alphabetic orderin
Fearless Luminance Adaptation: A Macro-Micro-Hierarchical Transformer for Exposure Correction
Photographs taken with less-than-ideal exposure settings often display poor
visual quality. Since the correction procedures vary significantly, it is
difficult for a single neural network to handle all exposure problems.
Moreover, the inherent limitations of convolutions, hinder the models ability
to restore faithful color or details on extremely over-/under- exposed regions.
To overcome these limitations, we propose a Macro-Micro-Hierarchical
transformer, which consists of a macro attention to capture long-range
dependencies, a micro attention to extract local features, and a hierarchical
structure for coarse-to-fine correction. In specific, the complementary
macro-micro attention designs enhance locality while allowing global
interactions. The hierarchical structure enables the network to correct
exposure errors of different scales layer by layer. Furthermore, we propose a
contrast constraint and couple it seamlessly in the loss function, where the
corrected image is pulled towards the positive sample and pushed away from the
dynamically generated negative samples. Thus the remaining color distortion and
loss of detail can be removed. We also extend our method as an image enhancer
for low-light face recognition and low-light semantic segmentation. Experiments
demonstrate that our approach obtains more attractive results than
state-of-the-art methods quantitatively and qualitatively.Comment: Accepted by ACM MM 202
Optimization of the design of ducted-fan hovering micro air vehicles using finite element simulation and orthogonal design
The structural design and flight stability characteristics of micro air vehicles have received much attention due to its low Reynolds number. Compared with fixed-wing aircraft, hovering ducted-fan micro air vehicles with vertical takeoff and landing and hovering capabilities have promising prospect. In this article, a flexible membrane and inflatable structure has been used as the aerodynamic shape of an aircraft model. Its advantages have been analyzed and verified by fluid-structure interaction based on finite element method. The flight stability of hovering micro air vehicles has also been investigated based on the theory of motion of structure. In order to improve the flight stability of the designed hovering micro air vehicle model, the effects of geometrical parameters and materials have been analyzed through an orthogonal experimental design. Based on the optimized results, the aircraft prototype has been manufactured for experimental test. The elastic deformation produced on its flexible membrane structure is obtained by stroboscopic stereo imaging method and a purpose-built experimental environment. The numerical simulation results indicated that the thickness of membrane and material of vertical duct have significant effects on the micro air vehicle flight stability and disturbance resistance ability. The results have confirmed that the flexible aerodynamic mechanisms produced by the aeroelastic deformation of spherical membrane can enhance the micro air vehicle stability.This work was financially supported by Support Program of National Ministry of Education of China
(No. 625010110), National Natural Science Foundation of China (No. 61179043), and Specialized Research
Fund for the Doctoral Program (SRFDP) of Higher Education (No. 20070056085)
Isotropic Band Gaps and Freeform Waveguides Observed in Hyperuniform Disordered Photonic Solids
Recently, disordered photonic media and random textured surfaces have
attracted increasing attention as strong light diffusers with broadband and
wide-angle properties. We report the first experimental realization of an
isotropic complete photonic band gap (PBG) in a two-dimensional (2D) disordered
dielectric structure. This structure is designed by a constrained-optimization
method, which combines advantages of both isotropy due to disorder and
controlled scattering properties due to low density fluctuations
(hyperuniformity) and uniform local topology. Our experiments use a modular
design composed of Al2O3 walls and cylinders arranged in a hyperuniform
disordered network. We observe a complete PBG in the microwave region, in good
agreement with theoretical simulations, and show that the intrinsic isotropy of
this novel class of PBG materials enables remarkable design freedom, including
the realization of waveguides with arbitrary bending angles impossible in
photonic crystals. This first experimental verification of a complete PBG and
realization of functional defects in this new class of materials demonstrates
their potential as building blocks for precise manipulation of photons in
planar optical micro-circuits and has implications for disordered acoustic and
electronic bandgap materials
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