267 research outputs found

    Geo-located Twitter as the proxy for global mobility patterns

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    In the advent of a pervasive presence of location sharing services researchers gained an unprecedented access to the direct records of human activity in space and time. This paper analyses geo-located Twitter messages in order to uncover global patterns of human mobility. Based on a dataset of almost a billion tweets recorded in 2012 we estimate volumes of international travelers in respect to their country of residence. We examine mobility profiles of different nations looking at the characteristics such as mobility rate, radius of gyration, diversity of destinations and a balance of the inflows and outflows. The temporal patterns disclose the universal seasons of increased international mobility and the peculiar national nature of overseen travels. Our analysis of the community structure of the Twitter mobility network, obtained with the iterative network partitioning, reveals spatially cohesive regions that follow the regional division of the world. Finally, we validate our result with the global tourism statistics and mobility models provided by other authors, and argue that Twitter is a viable source to understand and quantify global mobility patterns.Comment: 17 pages, 13 figure

    I Am Waiting For To-Morrow To Come

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    https://digitalcommons.library.umaine.edu/mmb-vp/4938/thumbnail.jp

    A similar correction mechanism in slow and fluent readers after suboptimal landing positions

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    The present eye movements study investigated the optimal viewing position (OVP) and inverted-optimal viewing position (I-OVP) effects in slow readers. The basis of these effects is a phenomenon called corrective re-fixations, which describes a short saccade from a suboptimal landing position (word beginning or end) to the center of the word. The present study found corrective re-fixations in slow readers, which was evident from the I-OVP effects in first fixation durations, the OVP effect in number of fixations and the OVP effect in re-fixation probability. The main result is that slow readers, despite being characterized by a fragmented eye movement pattern during reading, nevertheless share an intact mechanism for performing corrective re-fixations. This correction mechanism is not linked to linguistic processing, but to visual and oculomotor processes, which suggests the integrity of oculomotor and visual processes in slow readers

    Systematic influence of gaze position on pupil size measurement: analysis and correction

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    Cognitive effort is reflected in pupil dilation, but the assessment of pupil size is potentially susceptible to changes in gaze position. This study exemplarily used sentence reading as a stand-in for paradigms that assess pupil size in tasks during which changes in gaze position are unavoidable. The influence of gaze position on pupil size was first investigated by an artificial eye model with a fixed pupil size. Despite its fixed pupil size, the systematic measurements of the artificial eye model revealed substantial gaze-position-dependent changes in the measured pupil size. We evaluated two functions and showed that they can accurately capture and correct the gaze-dependent measurement error of pupil size recorded during a sentence-reading and an effortless z-string-scanning task. Implications for previous studies are discussed, and recommendations for future studies are provided

    Scaling of city attractiveness for foreign visitors through big data of human economical and social media activity

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    Scientific studies investigating laws and regularities of human behavior are nowadays increasingly relying on the wealth of widely available digital information produced by human social activity. In this paper we leverage big data created by three different aspects of human activity (i.e., bank card transactions, geotagged photographs and tweets) in Spain for quantifying city attractiveness for the foreign visitors. An important finding of this papers is a strong superlinear scaling of city attractiveness with its population size. The observed scaling exponent stays nearly the same for different ways of defining cities and for different data sources, emphasizing the robustness of our finding. Temporal variation of the scaling exponent is also considered in order to reveal seasonal patterns in the attractivenessComment: 8 pages, 3 figures, 1 tabl

    Mining Urban Performance: Scale-Independent Classification of Cities Based on Individual Economic Transactions

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    Intensive development of urban systems creates a number of challenges for urban planners and policy makers in order to maintain sustainable growth. Running efficient urban policies requires meaningful urban metrics, which could quantify important urban characteristics including various aspects of an actual human behavior. Since a city size is known to have a major, yet often nonlinear, impact on the human activity, it also becomes important to develop scale-free metrics that capture qualitative city properties, beyond the effects of scale. Recent availability of extensive datasets created by human activity involving digital technologies creates new opportunities in this area. In this paper we propose a novel approach of city scoring and classification based on quantitative scale-free metrics related to economic activity of city residents, as well as domestic and foreign visitors. It is demonstrated on the example of Spain, but the proposed methodology is of a general character. We employ a new source of large-scale ubiquitous data, which consists of anonymized countrywide records of bank card transactions collected by one of the largest Spanish banks. Different aspects of the classification reveal important properties of Spanish cities, which significantly complement the pattern that might be discovered with the official socioeconomic statistics.Comment: 10 pages, 7 figures, to be published in the proceedings of ASE BigDataScience 2014 conferenc

    I am waiting for to-morrow to come

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    A snow-covered cabin at night / H. Linder.https://scholarsjunction.msstate.edu/cht-sheet-music/4173/thumbnail.jp

    No Effect of cathodal tDCS of the posterior parietal cortex on parafoveal preprocessing of words

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    Abstract The present study investigated the functional role of the posterior parietal cortex during the processing of parafoveally presented letter strings. To this end, we simultaneously presented two letter strings (word or pseudoword) – one foveally and one parafoveally – and asked the participants to indicate the presence of a word (i.e., lexical decision flanker task). We applied cathodal transcranial direct current stimulation (tDCS) over the posterior parietal cortex in order to establish causal links between brain activity and lexical decision performance (accuracy and latency). The results indicated that foveal stimulus difficulty affected the amount of parafoveally processed information. Bayes factor analysis showed no effects of brain stimulation suggesting that posterior parietal cathodal tDCS does not modulate attention-related processes during parafoveal preprocessing. This result is discussed in the context of recent tDCS studies on attention and performance
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