Large magnetic circular dichroism in resonant inelastic x-ray scattering at the Mn L-edge of Mn-Zn ferrite

We report resonant inelastic x-ray scattering (RIXS) excited by circularly polarized x-rays on Mn-Zn ferrite at the Mn L2,3-resonances. We demonstrate that crystal field excitations, as expected for localized systems, dominate the RIXS spectra and thus their dichroic asymmetry cannot be interpreted in terms of spin-resolved partial density of states, which has been the standard approach for RIXS dichroism. We observe large dichroic RIXS at the L2-resonance which we attribute to the absence of metallic core hole screening in the insulating Mn-ferrite. On the other hand, reduced L3-RIXS dichroism is interpreted as an effect of longer scattering time that enables spin-lattice core hole relaxation via magnons and phonons occurring on a femtosecond time scale.Comment: 7 pages, 2 figures, http://link.aps.org/doi/10.1103/PhysRevB.74.17240

Anisotropic Electron Spin Lifetime in (In,Ga)As/GaAs (110) Quantum Wells

Anisotropic electron spin lifetimes in strained undoped (In,Ga)As/GaAs (110) quantum wells of different width and height are investigated by time-resolved Faraday rotation and time-resolved transmission and are compared to the (001)-orientation. From the suppression of spin precession, the ratio of in-plane to out-of-plane spin lifetimes is calculated. Whereas the ratio increases with In concentration in agreement with theory, a surprisingly high anisotropy of 480 is observed for the broadest quantum well, when expressed in terms of spin relaxation times.Comment: 4 pages, 4 figures, revise

Informal Disaster Diplomacy

This paper develops a baseline and definition for informal disaster diplomacy in order to fill in an identified gap in the existing research. The process adopted is a review of the concept of informality, the application of informality to diplomacy, and the application of informality to disasters and disaster science. The two applications of informality are then combined to outline an informal disaster diplomacy as a conceptual contribution to studies where processes of conflict, peace, and disasters interact. Adding informality into disaster diplomacy provides originality and significance as it has not hitherto been fully examined in this context. This exploration results in insights into disaster, peace, and conflict research through two main contributions. First, the paper recognises that informal disaster diplomacy has frequently been present in disaster diplomacy analyses, but has rarely been explicitly presented, accepted, described, theorised, or analysed. Second, by explaining the presence of and contributions from informality, the discussion assists in re-balancing much of disaster diplomacy research with depth from conflict research, peace research, international relations, and political science

Analysing the behaviour of robot teams through relational sequential pattern mining

This report outlines the use of a relational representation in a Multi-Agent domain to model the behaviour of the whole system. A desired property in this systems is the ability of the team members to work together to achieve a common goal in a cooperative manner. The aim is to define a systematic method to verify the effective collaboration among the members of a team and comparing the different multi-agent behaviours. Using external observations of a Multi-Agent System to analyse, model, recognize agent behaviour could be very useful to direct team actions. In particular, this report focuses on the challenge of autonomous unsupervised sequential learning of the team's behaviour from observations. Our approach allows to learn a symbolic sequence (a relational representation) to translate raw multi-agent, multi-variate observations of a dynamic, complex environment, into a set of sequential behaviours that are characteristic of the team in question, represented by a set of sequences expressed in first-order logic atoms. We propose to use a relational learning algorithm to mine meaningful frequent patterns among the relational sequences to characterise team behaviours. We compared the performance of two teams in the RoboCup four-legged league environment, that have a very different approach to the game. One uses a Case Based Reasoning approach, the other uses a pure reactive behaviour.Comment: 25 page

Digital Technology and Marketing Management Capability: Achieving Growth in SMEs

Purpose The purpose of this study is to evaluate the relationships between digital technology, tangible/intangible assets and marketing capabilities to gain more insight into the factors related to small- and medium-sized enterprises’ (SMEs’) growth in the UK. Based on the resource-advantage theory, this research addresses the question “to what extent does digital technology influence marketing capability which leads to companies’ growth?” Design/methodology/approach Data were gathered through 21 in-depth interviews with managers from different multinational organizations and six focus groups with employees. Findings The study identifies the two key components of digital technology as information quality and service convenience. In addition, the relationships between digital technology, tangible/intangible assets and marketing capabilities perform the significant role of facilitator of a company’s growth. Research limitations/implications The focus on UK SMEs limits the generalizability of the results. Further studies should be conducted in other sectors and country settings to examine the associations identified in the current study. Originality/value This study identifies the main impacts of digital technology on intellectual/physical assets. While managers and employees have specified that marketing capability is significant for organizations, there are a few other areas of concern with regard to consequences related to a company’s growth, competence and core competence, particularly in an SME’s setting. Keyword

Brownian motion in a non-homogeneous force field and photonic force microscope

The Photonic Force Microscope (PFM) is an opto-mechanical technique based on an optical trap that can be assumed to probe forces in microscopic systems. This technique has been used to measure forces in the range of pico- and femto-Newton, assessing the mechanical properties of biomolecules as well as of other microscopic systems. For a correct use of the PFM, the force field to measure has to be invariable (homogeneous) on the scale of the Brownian motion of the trapped probe. This condition implicates that the force field must be conservative, excluding the possibility of a rotational component. However, there are cases where these assumptions are not fulfilled Here, we show how to improve the PFM technique in order to be able to deal with these cases. We introduce the theory of this enhanced PFM and we propose a concrete analysis workflow to reconstruct the force field from the experimental time-series of the probe position. Furthermore, we experimentally verify some particularly important cases, namely the case of a conservative or rotational force-field

Measured and Simulated Acoustic Signature of a Full-Scale Aircraft with Airframe Noise Reduction Technology Installed

Microphone phased-array and pole-mounted microphone data gathered during the NASA Acoustics Research Measurements flight tests were used to benchmark results from companion full-scale aeroacoustics simulations. Conducted with the lattice Boltzmann solver PowerFLOW, the simulations predicted the acoustic behavior of various tested aircraft configurations. Emphasis was placed on those flown during the third flight test - a Fowler flap-equipped Gulfstream G-III with and without noise abatement technology on the main landing gear. Direct comparisons between experimental and synthetic microphone phasedarray data were achieved by applying the same processing and deconvolution technique to both sets of data. To extend the validation of the computations to the metric used for noise certification, the Effective Perceived Noise Level, a high-fidelity digital model of the nose landing gear, which was excluded from earlier computations, was developed and integrated into the G-III aircraft geometry. The acoustic study presented here demonstrates that the simulated beamform maps and corresponding integrated farfield spectra accurately predict the locations and strengths of the prominent airframe noise sources present on the G-III aircraft

Informal Disaster Governance

Scholars and practitioners are increasingly questioning formal disaster governance (FDG) approaches as being too rigid, slow, and command-and-control driven. Too often, local realities and non-formal influences are sidelined or ignored to the extent that disaster governance can be harmed through the efforts to impose formal and/or political structures. A contrasting narrative emphasises so-called bottom-up, local, and/or participatory approaches which this article proposes to encapsulate as Informal Disaster Governance (IDG). This article theorises IDG and situates it within the long-standing albeit limited literature on the topic, paying particular attention to the literature’s failure to properly define informal disaster risk reduction and response efforts, to conceptualise their far-reaching extent and consequences, and to consider their ‘dark sides.’ By presenting IDG as a framework, this article restores the conceptual importance and balance of IDG vis-à-vis FDG, paving the way for a better understanding of the ‘complete’ picture of disaster governance. This framework is then considered in a location where IDG might be expected to be more powerful or obvious, namely in a smaller, more isolated, and tightly knit community, characteristics which are stereotypically used to describe island locations. Thus, Svalbard in the Arctic has been chosen as a case study, including its handling of the 2020 Covid-19 pandemic, to explore the merits and challenges with shifting the politics of disaster governance towards IDG