Using complex adaptive systems and technology to analyse the strength of processes and cultural indicators: a method to improve sustained competitive advantage

This paper generalises and strengthens the investigation of capturing intangible data for the benefit of organisations encouraging learning environments and self-organisation practices. It suggests current technological and algorithmic analysis may aid an organisation’s quest for sustained competitive advantage through the identification of previously unobservable data including cultural nuances. However, the implementation of such an approach presents challenges of which we summarise in our conclusion

Atomization Mechanism of Internally Mixing Twin-Fluid Y-Jet Atomizer

The atomization mechanism of the gas-liquid multiphase flow through an internally mixing twin-fluid Y-jet atomizer has been studied by examining both the internal and external flow patterns. Superheated steam and light fuel oil (LFO) are used as working fluids. The flow is numerically modeled using the compressible Navier-Stokes equations; the hybrid large eddy simulation approach through wall-modeled large eddy simulations (WMLES) is used to resolve the turbulence with the large eddy simulations, whereas the Prandtl mixing length model is used for modeling the subgrid-scale structures, which are affected by operational parameters. A volume-of-fluid to discrete phase model (VOF-to-DPM) transition mechanism is utilized along with dynamic solution-adaptive mesh refinement to predict the initial development and fragmentation of the gas-liquid interface through VOF formulations on a sufficiently fine mesh, while DPM is used to predict the dispersed part of the spray on the coarser grid. Two operational parameters, namely, gas-to-liquid mass flow rate ratio (GLR) and liquid-to-gas momentum ratio, are compared; the latter is found to be an appropriate operational parameter to describe both the internal flow and atomization characteristics. It is confirmed that the variation in the flow patterns within the mixing port of the atomizer coincides with the variation of the spatial distribution of the spray drops

Experimentally testing and assessing the predictive power of species assembly rules for tropical canopy ants.

Understanding how species assemble into communities is a key goal in ecology. However, assembly rules are rarely tested experimentally, and their ability to shape real communities is poorly known. We surveyed a diverse community of epiphyte-dwelling ants and found that similar-sized species co-occurred less often than expected. Laboratory experiments demonstrated that invasion was discouraged by the presence of similarly sized resident species. The size difference for which invasion was less likely was the same as that for which wild species exhibited reduced co-occurrence. Finally we explored whether our experimentally derived assembly rules could simulate realistic communities. Communities simulated using size-based species assembly exhibited diversities closer to wild communities than those simulated using size-independent assembly, with results being sensitive to the combination of rules employed. Hence, species segregation in the wild can be driven by competitive species assembly, and this process is sufficient to generate observed species abundance distributions for tropical epiphyte-dwelling ants.TMF was funded by the UK Natural Environment Research Council, the project “Biodiversity of Forest Ecosystems” CZ.1.07/2.3.00/20.0064 co-financed by the European Social Fund and the state budget of the Czech Republic, an Australian Research Council Discovery Grant (DP140101541), Yayasan Sime Darby, and the Czech Science Foundation (Reg, nos. 14-32302S,14-04258S).This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/ele.12403/abstract

Complex Langevin and other approaches to the sign problem in quantum many-body physics

We review the theory and applications of complex stochastic quantization to the quantum many-body problem. Along the way, we present a brief overview of a number of ideas that either ameliorate or in some cases altogether solve the sign problem, including the classic reweighting method, alternative Hubbard-Stratonovich transformations, dual variables (for bosons and fermions), Majorana fermions, density-of-states methods, imaginary asymmetry approaches, and Lefschetz thimbles. We discuss some aspects of the mathematical underpinnings of conventional stochastic quantization, provide a few pedagogical examples, and summarize open challenges and practical solutions for the complex case. Finally, we review the recent applications of complex Langevin to quantum field theory in relativistic and nonrelativistic quantum matter, with an emphasis on the nonrelativistic case.Comment: 51 pages, 19 figures, review articl

Charmonium spectroscopy and mixing with light quark and open charm states from nF=2 lattice QCD

We study the charmonium spectrum including higher spin and gluonic excitations. We determine an upper limit on the mixing of the eta_c ground state with light pseudoscalar flavour-singlet mesons and investigate the mixing of charmonia near open charm thresholds with pairs of (excited) D and anti-D mesons. For charm and light valence quarks and nF=2 sea quarks, we employ the non-perturbatively improved Sheikholeslami-Wohlert (clover) action. Excited states are accessed using the variational technique, starting from a basis of suitably optimised operators. For some aspects of this study, the use of improved stochastic all-to-all propagators was essential.Comment: 23 pages, v2: references updated, correction of an ambiguous statement, minor typos corrected, some figures update

Melody Transcription From Music Audio: Approaches and Evaluation

Although the process of analyzing an audio recording of a music performance is complex and difficult even for a human listener, there are limited forms of information that may be tractably extracted and yet still enable interesting applications. We discuss melody--roughly, the part a listener might whistle or hum--as one such reduced descriptor of music audio, and consider how to define it, and what use it might be. We go on to describe the results of full-scale evaluations of melody transcription systems conducted in 2004 and 2005, including an overview of the systems submitted, details of how the evaluations were conducted, and a discussion of the results. For our definition of melody, current systems can achieve around 70% correct transcription at the frame level, including distinguishing between the presence or absence of the melody. Melodies transcribed at this level are readily recognizable, and show promise for practical applications

Synthetic Light-Activated Ion Channels for Optogenetic Activation and Inhibition

Optogenetic manipulation of cells or living organisms became widely used in neuroscience following the introduction of the light-gated ion channel channelrhodopsin-2 (ChR2). ChR2 is a non-selective cation channel, ideally suited to depolarize and evoke action potentials in neurons. However, its calcium (Ca2+) permeability and single channel conductance are low and for some applications longer-lasting increases in intracellular Ca2+ might be desirable. Moreover, there is need for an efficient light-gated potassium (K+) channel that can rapidly inhibit spiking in targeted neurons. Considering the importance of Ca2+ and K+ in cell physiology, light-activated Ca2+-permeant and K+-specific channels would be welcome additions to the optogenetic toolbox. Here we describe the engineering of novel light-gated Ca2+-permeant and K+-specific channels by fusing a bacterial photoactivated adenylyl cyclase to cyclic nucleotide-gated channels with high permeability for Ca2+ or for K+, respectively. Optimized fusion constructs showed strong light-gated conductance in Xenopus laevis oocytes and in rat hippocampal neurons. These constructs could also be used to control the motility of Drosophila melanogaster larvae, when expressed in motoneurons. Illumination led to body contraction when motoneurons expressed the light-sensitive Ca2+-permeant channel, and to body extension when expressing the light-sensitive K+ channel, both effectively and reversibly paralyzing the larvae. Further optimization of these constructs will be required for application in adult flies since both constructs led to eclosion failure when expressed in motoneurons

Design of a five-axis ultra-precision micro-milling machine—UltraMill. Part 1: Holistic design approach, design considerations and specifications

High-accuracy three-dimensional miniature components and microstructures are increasingly in demand in the sector of electro-optics, automotive, biotechnology, aerospace and information-technology industries. A rational approach to mechanical micro machining is to develop ultra-precision machines with small footprints. In part 1 of this two-part paper, the-state-of-the-art of ultra-precision machines with micro-machining capability is critically reviewed. The design considerations and specifications of a five-axis ultra-precision micro-milling machine—UltraMill—are discussed. Three prioritised design issues: motion accuracy, dynamic stiffness and thermal stability, formulate the holistic design approach for UltraMill. This approach has been applied to the development of key machine components and their integration so as to achieve high accuracy and nanometer surface finish

Core reconstruction in pseudopotential calculations

A new method is presented for obtaining all-electron results from a pseudopotential calculation. This is achieved by carrying out a localised calculation in the region of an atomic nucleus using the embedding potential method of Inglesfield [J.Phys. C {\bf 14}, 3795 (1981)]. In this method the core region is \emph{reconstructed}, and none of the simplifying approximations (such as spherical symmetry of the charge density/potential or frozen core electrons) that previous solutions to this problem have required are made. The embedding method requires an accurate real space Green function, and an analysis of the errors introduced in constructing this from a set of numerical eigenstates is given. Results are presented for an all-electron reconstruction of bulk aluminium, for both the charge density and the density of states.Comment: 14 pages, 5 figure