1,471 research outputs found

    Assessment of the potential of MERIS near-infrared water vapour products to correct ASAR interferometric measurements

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    Atmospheric water vapour is a major limitation for high precision Interferometric Synthetic Aperture Radar (InSAR) applications due to its significant impact on microwave signals. We propose a statistical criterion to test whether an independent water vapour product can reduce water vapour effects on InSAR interferograms, and assess the potential of the Medium Resolution Imaging Spectrometer (MERIS) near-infrared water vapour products for correcting Advanced SAR (ASAR) data. Spatio-temporal comparisons show c. 1.1mm agreement between MERIS and GPS/radiosonde water vapour products in terms of standard deviations. One major limitation with the use of MERIS water vapour products is the frequency of cloud free conditions. Our analysis indicates that in spite of the low global cloud free conditions (~25%), the frequency can be much higher for certain areas such as Eastern Tibet (~38%) and Southern California (~48%). This suggests that MERIS water vapour products show potential for correcting ASAR interferometric measurements in certain regions

    An appeal for a methodological fusion of conversation analysis and experimental psychology

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    ©, Published with license by Taylor & Francis. © 2017 J. P. de Ruiter and Saul Albert. Human social interaction is studied by researchers in conversation analysis (CA) and psychology, but the dominant methodologies within these two disciplines are very different. Analyzing methodological differences in relation to major developments in the philosophy of science, we suggest that a central difference is that psychologists tend to follow Popper’s falsificationism in dissociating the context of discovery and the context of justification. In CA, following Garfinkel’s ethnomethodology, these two contexts are much closer to one another, if not inextricable. While this dissociation allows the psychologist a much larger theoretical freedom, because psychologists “only” need to validate their theories by generating confirmed predictions from experiments, it also carries the risk of generating theories that are less robust and pertinent to everyday interaction than the body of knowledge accumulated by CA. However, as long as key philosophical differences are well understood, it is not an inherently bad idea to generate predictions from theories and use quantitative and experimental methods to test them. It is both desirable and achievable to find a synthesis between methodologies that combines their strengths and avoids their weaknesses. We discuss a number of challenges that would need to be met and some opportunities that may arise from creating such a synthesis

    Improving human interaction research through ecological grounding

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    In psychology, we tend to follow the general logic of falsificationism: we separate the ‘context of discovery’ (how we come up with theories) from the ‘context of justification’ (how we test them). However, when studying human interaction, separating these contexts can lead to theories with low ecological validity that do not generalize well to life outside the lab. We propose borrowing research procedures from well-established inductive methodologies in interaction research during the process of discovering new regularities and analyzing natural data without being led by theory. We introduce research procedures including the use of naturalistic study settings, analytic transcription, collections of cases, and data analysis sessions, and illustrate these with examples from a successful cross-disciplinary study. We argue that if these procedures are used systematically and transparently throughout a research cycle, they will lead to more robust and ecologically valid theories about interaction within psychology and, with some adaptation, can enhance the reproducibility of research across many other areas of psychological science

    Repair: The interface between interaction and cognition

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    Copyright © 2018 The Authors. Topics in Cognitive Science published by Wiley Periodicals, Inc. on behalf of Cognitive Science Society. Conversational repair is the process people use to detect and resolve problems of speaking, hearing, and understanding. Through repair, participants in social interaction display how they establish and maintain communication and mutual understanding. We argue that repair provides a crucial theoretical interface for research between diverse approaches to studying human interaction. We provide an overview of conversation analytic findings about repair in order to encourage further cross-disciplinary research involving both detailed inductive inquiry and more theory-driven experimental approaches. We outline CA's main typologies of repair and its methodological rationale, and we provide transcripts and examples that readers can explore for themselves using open data from online corpora. Since participants in interaction use repair to deal with problems as they emerge at the surface level of talk, we conclude that repair can be a point of convergence for studying mis/communication from multiple methodological perspectives

    Be a Fulbright Scholar—Lessons and Experiences of AIS Fulbright Scholars

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    To achieve a truly global perspective in information systems (IS) that enhances education and research, IS academics can do more than study and teach global IS topics. We encourage IS academics to engage in an international immersion experience themselves. The article describes experiences of Fulbright Scholars, and argues for the need of more global education for IS academics. These views were presented during a panel session at the Americas Conference on Information Systems (AMCIS) 2012. The panelists touched on logistical issues such as grant application, living conditions, working with a host institution’s faculty and students, and receiving support from their home university. Participants shared their experiences in India, Poland, Portugal, the Azores, Mongolia, and Nepal. The article concludes with lessons learned

    Uniqueness and Nondegeneracy of Ground States for (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1} = 0 in R\mathbb{R}

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    We prove uniqueness of ground state solutions Q=Q(∣x∣)≄0Q = Q(|x|) \geq 0 for the nonlinear equation (−Δ)sQ+Q−Qα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1}= 0 in R\mathbb{R}, where 0<s<10 < s < 1 and 0<α<4s1−2s0 < \alpha < \frac{4s}{1-2s} for s<1/2s < 1/2 and 0<α<∞0 < \alpha < \infty for s≄1/2s \geq 1/2. Here (−Δ)s(-\Delta)^s denotes the fractional Laplacian in one dimension. In particular, we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for s=1/2s=1/2 and α=1\alpha=1 in [Acta Math., \textbf{167} (1991), 107--126]. As a technical key result in this paper, we show that the associated linearized operator L+=(−Δ)s+1−(α+1)QαL_+ = (-\Delta)^s + 1 - (\alpha+1) Q^\alpha is nondegenerate; i.\,e., its kernel satisfies ker L+=span {Qâ€Č}\mathrm{ker}\, L_+ = \mathrm{span}\, \{Q'\}. This result about L+L_+ proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for nonlinear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page
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