In search of the drivers of high growth in manufacturing SMEs

Though considerable attention in the extant literature has been devoted to growth and performance of firms, there is a dearth of research on high growth firms. Furthermore, the majority of literature in this area focuses on large firms while research on high growth small firms is underdeveloped. This paper investigates the drivers of high growth in manufacturing SMEs. Following a number of focus group interviews with six managing directors of manufacturing firms, a number of drivers of high growth were identified and investigated in a sample of 207 manufacturing SMEs. The results of this study indicate that high growth firms place a greater emphasis on external drivers such as strategic orientation, their operating environment and the use of e-commerce compared with firms having static or declining sales. The analysis shows that high growth firms compete largely on the basis of price. While high growth firms have increased their sales by over 30% during the past three years or longer, it is questionable if manufacturing firms can sustain their competitive advantage without recourse to greater research and development, and innovation in the longer term

Generalized Wannier functions: a comparison of molecular electric dipole polarizabilities

Localized Wannier functions provide an efficient and intuitive means by which to compute dielectric properties from first principles. They are most commonly constructed in a post-processing step, following total-energy minimization. Nonorthogonal generalized Wannier functions (NGWFs) [Skylaris et al., Phys. Rev. B 66, 035119 11 (2002); Skylaris et al., J. Chem. Phys. 122, 084119 (2005)] may also be optimized in situ, in the process of solving for the ground-state density. We explore the relationship between NGWFs and orthonormal, maximally localized Wannier functions (MLWFs) [Marzari and Vanderbilt, Phys. Rev. B 56, 12847 (1997); Souza, Marzari, and Vanderbilt, ibid. 65, 035109 (2001)], demonstrating that NGWFs may be used to compute electric dipole polarizabilities efficiently, with no necessity for post-processing optimization, and with an accuracy comparable to MLWFs.Comment: 5 pages, 1 figure. This version matches that accepted for Physical Review B on 4th May 201

Subspace representations in ab initio methods for strongly correlated systems

We present a generalized definition of subspace occupancy matrices in ab initio methods for strongly correlated materials, such as DFT+U and DFT+DMFT, which is appropriate to the case of nonorthogonal projector functions. By enforcing the tensorial consistency of all matrix operations, we are led to a subspace projection operator for which the occupancy matrix is tensorial and accumulates only contributions which are local to the correlated subspace at hand. For DFT+U in particular, the resulting contributions to the potential and ionic forces are automatically Hermitian, without resort to symmetrization, and localized to their corresponding correlated subspace. The tensorial invariance of the occupancies, energies and ionic forces is preserved. We illustrate the effect of this formalism in a DFT+U study using self-consistently determined projectors.Comment: 15 pages, 8 figures. This version (v2) matches that accepted for Physical Review B on 15th April 201

Towards a Productive Aesthetics: History and Now-Time in Blake and Brecht

This thesis is a comparison of the theory and practice of aesthetic politics in key works of Bertolt Brecht and William Blake. I argue that there are two separate temporal moments that define Brechts and Blakes political aesthetics. The first moment is defined by a more direct engagement with the nowness and relative newness of their capitalist social world. Capitalist social relations bring out in each of the two a more directly engaging oppositional aesthetics. Given capitalisms desire to create a form of experience that not only makes sense for its subjects own subjugation, while while also attempting to negate any possible alterative to itself, Brecht and Blake develop a political aesthetics that exposes and undercuts these dominant forms of experience. Using Walter Benjamin, I argue that Brecht and Blake posit an oppositional aesthetics of the now which takes seriously capitalisms desires and successes in refashioning experience, but provides a means of both understanding this experience while counterposing and making desirable an oppositional form of existence. This political aesthetic response is grounded in contemporary social relations and responds using this as a framework of reference. The second moment under discussion examines the role of history and historical representation in Brecht and Blake. The central focus is how Brecht and Blake continue the responsive project referenced in the first two chapters by making use of history in aesthetic-political interventions in the present. I argue that they engage historical tropes and use history against the grain in the Jetztzeit (Now-Time), as Benjamin notes. Both repurpose history as a means to produce historical recoveries, making failures or losses in the past open for radical productive possibilities in the present. In this way forms of inherited experience or preconceived truths are placed in a space of contestation. Historical representation is another opportunity to cleave open an oppositional aesthetics and unsettle that which capitalism wishes to make silent

Projector self-consistent DFT+U using non-orthogonal generalized Wannier functions

We present a formulation of the density-functional theory + Hubbard model (DFT+U) method that is self-consistent over the choice of Hubbard projectors used to define the correlated subspaces. In order to overcome the arbitrariness in this choice, we propose the use of non-orthogonal generalized Wannier functions (NGWFs) as projectors for the DFT+U correction. We iteratively refine these NGWF projectors and, hence, the DFT+U functional, such that the correlated subspaces are fully self-consistent with the DFT+U ground-state. We discuss the convergence characteristics of this algorithm and compare ground-state properties thus computed with those calculated using hydrogenic projectors. Our approach is implemented within, but not restricted to, a linear-scaling DFT framework, opening the path to DFT+U calculations on systems of unprecedented size.Comment: 4 pages, 3 figures. This version (v2) matches that accepted for Physical Review B Rapid Communications on 26th July 201

Asymptotic properties for Volterra integro-dynamic systems

Using the resolvent matrix, a comparison principle and a useful equivalent system, we investigate the asymptotic behavior of linear Volterra integro-dynamic systems on time scales

Solar energy conversion

If solar energy is to become a practical alternative to fossil fuels, we must have efficient ways to convert photons into electricity, fuel, and heat. The need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience

Stratified decision forests for accurate anatomical landmark localization in cardiac images

Accurate localization of anatomical landmarks is an important step in medical imaging, as it provides useful prior information for subsequent image analysis and acquisition methods. It is particularly useful for initialization of automatic image analysis tools (e.g. segmentation and registration) and detection of scan planes for automated image acquisition. Landmark localization has been commonly performed using learning based approaches, such as classifier and/or regressor models. However, trained models may not generalize well in heterogeneous datasets when the images contain large differences due to size, pose and shape variations of organs. To learn more data-adaptive and patient specific models, we propose a novel stratification based training model, and demonstrate its use in a decision forest. The proposed approach does not require any additional training information compared to the standard model training procedure and can be easily integrated into any decision tree framework. The proposed method is evaluated on 1080 3D highresolution and 90 multi-stack 2D cardiac cine MR images. The experiments show that the proposed method achieves state-of-theart landmark localization accuracy and outperforms standard regression and classification based approaches. Additionally, the proposed method is used in a multi-atlas segmentation to create a fully automatic segmentation pipeline, and the results show that it achieves state-of-the-art segmentation accuracy