397 research outputs found

    Pattern languages in HCI: A critical review

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    This article presents a critical review of patterns and pattern languages in human-computer interaction (HCI). In recent years, patterns and pattern languages have received considerable attention in HCI for their potential as a means for developing and communicating information and knowledge to support good design. This review examines the background to patterns and pattern languages in HCI, and seeks to locate pattern languages in relation to other approaches to interaction design. The review explores four key issues: What is a pattern? What is a pattern language? How are patterns and pattern languages used? and How are values reflected in the pattern-based approach to design? Following on from the review, a future research agenda is proposed for patterns and pattern languages in HCI

    TDI noises transfer functions for LISA

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    The LISA mission is the future space-based gravitational wave (GW)observatory of the European Space Agency. It is formed by 3 spacecraftexchanging laser beams in order to form multiple real and virtualinterferometers. The data streams to be used in order to extract the largenumber and variety of GW sources are Time-Delay Interferometry (TDI) data. Oneimportant processing to produce these data is the TDI on-ground processingwhich recombines multiple interferometric on-board measurements to removecertain noise sources from the data such as laser frequency noise or spacecraftjitter. The LISA noise budget is therefore expressed at the TDI level in orderto account for the different TDI transfer functions applied for each noisesource and thus estimate their real weight on mission performance. In order toderive a usable form of these transfer functions, a model of the beams, themeasurements, and TDI have been developed, and several approximation have beenmade. A methodology for such a derivation has been established, as well asverification procedures. It results in a set of transfer functions, which arenow used by the LISA project, in particular in its performance model. Usingthese transfer functions, realistic noise curves for various instrumentalconfigurations are provided to data analysis algorithms and used for instrumentdesign.<br

    High-Resolution Energy and Intensity Measurements with CVD Diamond at REX-ISOLDE

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    A novel beam instrumentation device for the HIE-REX (High In-tensity and Energy REX) upgrade has been developed and tested at the On-Line Isotope Mass Separator ISOLDE, located at the European Laboratory for Particle Physics (CERN). This device is based on CVD diamond detector technology and is used for measuring the beam intensity, particle counting and measuring the energy spectrum of the beam. An energy resolution of 0.6% was measured at a carbon ion energy of 22.8 MeV. This corresponds to an energy spread of ± 140 keV

    Interacting Preformed Cooper Pairs in Resonant Fermi Gases

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    We consider the normal phase of a strongly interacting Fermi gas, which can have either an equal or an unequal number of atoms in its two accessible spin states. Due to the unitarity-limited attractive interaction between particles with different spin, noncondensed Cooper pairs are formed. The starting point in treating preformed pairs is the Nozi\`{e}res-Schmitt-Rink (NSR) theory, which approximates the pairs as being noninteracting. Here, we consider the effects of the interactions between the Cooper pairs in a Wilsonian renormalization-group scheme. Starting from the exact bosonic action for the pairs, we calculate the Cooper-pair self-energy by combining the NSR formalism with the Wilsonian approach. We compare our findings with the recent experiments by Harikoshi {\it et al.} [Science {\bf 327}, 442 (2010)] and Nascimb\`{e}ne {\it et al.} [Nature {\bf 463}, 1057 (2010)], and find very good agreement. We also make predictions for the population-imbalanced case, that can be tested in experiments.Comment: 10 pages, 6 figures, accepted version for PRA, discussion of the imbalanced Fermi gas added, new figure and references adde

    Repeatability of beach morphology change under identical wave forcing

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    Laboratory investigations of beach morphology change under wave action are undertaken to gain insight into coastal processes, design coastal structures and validate the predictions of numerical models. For the results of such experiments to be reliable, it is necessary that they are repeatable. The equilibrium beach concept, that beach morphology will evolve to a quasi-static equilibrium shape for a given forcing suggests that experiments should be repeatable to some degree. However, sediment transport in turbulent breaking and broken waves is complex and highly variable and the level of repeatability at different temporal and spatial scales is challenging to measure, as such, previous work has restricted comparisons to small numbers of waves. Here we use the results of two identical, 20-h large-scale wave flume experiments to investigate the repeatability of sediment transport and beach morphology change under waves at timescales down to individual swash events. It is shown that while flow characteristics from identical swash events are very repeatable, the sediment transported can be very different in both magnitude and direction due to differences in turbulence, sediment advection and morphological feedback. Over longer periods containing multiple matching swash events however, the beach responds in a very similar manner, with the level of morphological repeatability increasing with time. The results also demonstrate that gross swash zone sediment transport remains high even as a beach profile approaches quasi-equilibrium, but the proportion of individual swash events that cause large sediment fluxes (>±7.5 kg/event/m) reduces with time. The results of this laboratory study indicate that beach morphology change has a level of determinism over timescales of several minutes and longer, giving confidence in the results from physical modelling studies. However, the large differences in sediment transport from apparently identical swash events questions the value in pursuing numerical predictions of sediment transport at the wave-by-wave timescale unless the reversals in sediment transport between apparently near identical swash events can also be predicted

    Developing a conceptual framework to analyse professionalisation in sport federations

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    Existing research on sport organisations is imprecise in the use of the concept 'professionalisation'. Furthermore, we do not know if analytical concepts of professionalisation correspond with the understanding in practice. This study explores the perceptions of practitioners and proposes a framework to analyse professionalisation in national sport federations. Expert interviews were conducted with six key people from Swiss national sport federations and then analysed these for characteristics of professionalisation using a hermeneutic approach. The characteristics were divided into three areas: (1) changed management philosophy, (2) functional differentiation and specialisation, and (3) application of management tools. However, professionalisation is primarily perceived to be a matter of 'professional' attitude that transforms into federation culture. The practitioners disclose an ambivalent view of professionalisation, e.g. business-like culture vs. voluntarism, for-profit vs. non-profit orientation, autonomy vs. control. A framework is developed that synthesises analytical concepts and practitioners' perceptions to support future comprehensive research into causes, forms and consequences of professionalisation in national sport federations

    Emotional Facial Expression Detection in the Peripheral Visual Field

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    BACKGROUND: In everyday life, signals of danger, such as aversive facial expressions, usually appear in the peripheral visual field. Although facial expression processing in central vision has been extensively studied, this processing in peripheral vision has been poorly studied. METHODOLOGY/PRINCIPAL FINDINGS: Using behavioral measures, we explored the human ability to detect fear and disgust vs. neutral expressions and compared it to the ability to discriminate between genders at eccentricities up to 40°. Responses were faster for the detection of emotion compared to gender. Emotion was detected from fearful faces up to 40° of eccentricity. CONCLUSIONS: Our results demonstrate the human ability to detect facial expressions presented in the far periphery up to 40° of eccentricity. The increasing advantage of emotion compared to gender processing with increasing eccentricity might reflect a major implication of the magnocellular visual pathway in facial expression processing. This advantage may suggest that emotion detection, relative to gender identification, is less impacted by visual acuity and within-face crowding in the periphery. These results are consistent with specific and automatic processing of danger-related information, which may drive attention to those messages and allow for a fast behavioral reaction

    Some Directions for Performance Improvement of Li-Ion Batteries out of Usual Paths

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    Recent developments at IMN will be shared on several research directions out of usual paths for performance improvement of Li-ion batteries. We will focus on innovative surface modifications of electrode components, new electrode compositions and architectures, and failure mechanism upon cycling by in-depth characterization through coupled advanced spectroscopic techniques. A molecular grafting approach has been proposed as a way to modify the interfacial chemical reactivity of oxide materials, which is detrimental to their long-term energy storage properties as electrodes of Li-ion batteries. Surface derivatization of powder oxide materials such as Li1.2V3O8 and Li(Mn,Ni)2O4 was accomplished by in situ electrografting of a diazonium salt during Li-ion intercalation, leading to a covalently bonded organic multilayer. Charge transfer is not impeded, while electrolyte decomposition is inhibited thus increasing the cycle life and decreasing the self-discharge. Carbon additives of classical porous electrodes occupy a large volume fraction which is lost for charge storage. Redox functionalization of the surface of some carbon additives has been successfully achieved through non-covalent grafting chemistry using multi-redox pyrene molecules synthesized on purpose. Such functionalized carbon additives have been used to increase the stored energy and power of C-coated LFP porous electrodes. Thicker electrodes are needed for higher energy density Li-ion batteries. We evaluate different directions in order to design new innovative electrode architectures for such a purpose. Our grafting chemistry has been further developed to achieve molecular junctions between non-carbon-coated LFP and multiwall carbon nanotubes (MWCNT) using a designed thiophene-based conjugated molecule. The strategy enables original architecturing of the cathode of Li-ion batteries, with the individual MWCNT being electronically nanocontacted at the surface of LFP grains. This advancement leads to much higher specific capacity and better capacity retention for non calendared thick electrodes, for which the electronic wiring of the electroactive material grains is a critical issue. Another direction followed is the use of conducting polymer additives in porous electrodes, which are able to act as both conducting fillers and mechanical reinforcement materials. We have synthesized a new form of lithium doped PANI, the excellent properties of which in terms of specific capacity, stability on cycling and rate capability will be presented. The coating of bare LFP particles with thin layers of this new Li-doped PANI allows surpassing the performance of commercial carbon coated LFP thick electrodes. The role of this PANI additive into millimetric thick electrodes of NMC material will also be discussed. Future developments of higher energy density Si-based Li-ion batteries depend on the mastering of side reactions at the Si anode. We will compare the SEI composition and morphology at the Si surface upon cycling in half cell and full Li-ion cell configurations using a combination of 7Li, 19F MAS NMR, XPS, TOF-SIMS and STEM-EELS. The origin of the much faster aging of Si-based full cells versus half cells and future directions for improvement will be discusse

    Auxin-regulated reversible inhibition of TMK1 signaling by MAKR2 modulates the dynamics of root gravitropism

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    Plants are able to orient their growth according to gravity, which ultimately controls both shoot and root architecture.1 Gravitropism is a dynamic process whereby gravistimulation induces the asymmetric distribution of the plant hormone auxin, leading to asymmetric growth, organ bending, and subsequent reset of auxin distribution back to the original pre-gravistimulation situation.1, 2, 3 Differential auxin accumulation during the gravitropic response depends on the activity of polarly localized PIN-FORMED (PIN) auxin-efflux carriers.1, 2, 3, 4 In particular, the timing of this dynamic response is regulated by PIN2,5,6 but the underlying molecular mechanisms are poorly understood. Here, we show that MEMBRANE ASSOCIATED KINASE REGULATOR2 (MAKR2) controls the pace of the root gravitropic response. We found that MAKR2 is required for the PIN2 asymmetry during gravitropism by acting as a negative regulator of the cell-surface signaling mediated by the receptor-like kinase TRANSMEMBRANE KINASE1 (TMK1).2,7, 8, 9, 10 Furthermore, we show that the MAKR2 inhibitory effect on TMK1 signaling is antagonized by auxin itself, which triggers rapid MAKR2 membrane dissociation in a TMK1-dependent manner. Our findings suggest that the timing of the root gravitropic response is orchestrated by the reversible inhibition of the TMK1 signaling pathway at the cell surface
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