120 research outputs found

    Validating Forward Modeling and Inversions of Helioseismic Holography Measurements

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    Here we use synthetic data to explore the performance of forward models and inverse methods for helioseismic holography. Specifically, this work presents the first comprehensive test of inverse modeling for flows using lateral-vantage (deep-focus) holography. We derive sensitivity functions in the Born approximation. We then use these sensitivity functions in a series of forward models and inversions of flows from a publicly available magnetohydrodynamic quiet-Sun simulation. The forward travel times computed using the kernels generally compare favorably with measurements obtained by applying holography, in a lateral-vantage configuration, on a 15-hour time series of artificial Dopplergrams extracted from the simulation. Inversions for the horizontal flow components are able to reproduce the flows in the upper 3Mm of the domain, but are compromised by noise at greater depths.Comment: accepted for publication by the Astrophysical

    Helioseismology of Pre-Emerging Active Regions II: Average Emergence Properties

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    We report on average subsurface properties of pre-emerging active regions as compared to areas where no active region emergence was detected. Helioseismic holography is applied to samples of the two populations (pre-emergence and without emergence), each sample having over 100 members, which were selected to minimize systematic bias, as described in Leka et al. We find that there are statistically significant signatures (i.e., difference in the means of more than a few standard errors) in the average subsurface flows and the apparent wave speed that precede the formation of an active region. The measurements here rule out spatially extended flows of more than about 15 m/s in the top 20 Mm below the photosphere over the course of the day preceding the start of visible emergence. These measurements place strong constraints on models of active region formation.Comment: 15 pages, 10 figures, ApJ (published

    MagicFace: Stepping into Character through an Augmented Reality Mirror

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    Augmented Reality (AR) is coming of age and appearing in various smartphone apps. One emerging AR type uses the front-facing camera and overlays a user's face with digital features that transform the physical appearance, making the user look like someone else, such as a popstar or a historical character. However, little is known about how people react to such stepping into character and how convincing they perceive it to be. We developed an app with two Egyptian looks, MagicFace, which was situated both in an opera house and a museum. In the first setting, people were invited to use the app, while in the second setting they came across it on their own when visiting the exhibition. Our findings show marked differences in how people approach and experience the MagicFace in these different contexts. We discuss how realistic and compelling this kind of AR technology is, as well as its implications for educational and cultural settings

    Revealing the Shopper Experience of Using a "Magic Mirror" Augmented Reality Make-Up Application

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    Virtual try-ons have recently emerged as a new form of Augmented Reality application. Using motion caption techniques, such apps show virtual elements like make-up or accessories superimposed over the real image of a person as if they were actually wearing them. However, there is as of yet little understanding about their value for providing a viable experience. We report on an in-situ study, observing how shoppers approach and respond to such a "Magic Mirror" in a store. Our findings show that after the initial surprise, the virtual try-on resulted in much exploration when shoppers looked at themselves on a display integrated in the make-up counter. Behavior tracking data from interactions with the mirror supported this. Moreover, survey data measured perceptions of augmentation as well as hedonic and utilitarian value of the app and suggested the augmented experience was perceived to be playful and credible while also acting as a strong driver for future behavior. We discuss opportunities and challenges that such technology brings for shopping and other domains

    Playing 'Tetris' reduces the strength, frequency and vividness of naturally occurring cravings.

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    Elaborated Intrusion Theory (EI) postulates that imagery is central to craving, therefore a visually based task should decrease craving and craving imagery. This study provides the first laboratory test of this hypothesis in naturally occurring, rather than artificially induced, cravings. Participants reported if they were experiencing a craving and rated the strength, vividness and intrusiveness of their craving. They then either played 'Tetris' or they waited for a computer program to load (they were told it would load, but it was designed not to). Before task completion, craving scores between conditions did not differ; after, however, participants who had played 'Tetris' had significantly lower craving and less vivid craving imagery. The findings support EI theory, showing that a visuospatial working memory load reduces naturally occurring cravings, and that Tetris might be a useful task for tackling cravings outside the laboratory. Methodologically, the findings show that craving can be studied in the laboratory without using craving induction procedures

    Investigation of an advanced fault tolerant integrated avionics system

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    Presented is an advanced, fault-tolerant multiprocessor avionics architecture as could be employed in an advanced rotorcraft such as LHX. The processor structure is designed to interface with existing digital avionics systems and concepts including the Army Digital Avionics System (ADAS) cockpit/display system, navaid and communications suites, integrated sensing suite, and the Advanced Digital Optical Control System (ADOCS). The report defines mission, maintenance and safety-of-flight reliability goals as might be expected for an operational LHX aircraft. Based on use of a modular, compact (16-bit) microprocessor card family, results of a preliminary study examining simplex, dual and standby-sparing architectures is presented. Given the stated constraints, it is shown that the dual architecture is best suited to meet reliability goals with minimum hardware and software overhead. The report presents hardware and software design considerations for realizing the architecture including redundancy management requirements and techniques as well as verification and validation needs and methods

    VisAge: Augmented reality for heritage

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    In this paper we describe the VisAge project, which explored how a community-based Augmented Reality (AR) system could be used to tell stories and cultural histories about urban environments. Our work focussed on two main themes - user engagement and immersiveness of the experience. To address the first theme, we developed an online portal where anybody could upload digital content and create their own stories using routes through a physical environment. To address the second theme, we developed a flexible, reconfigurable mobile platform to investigate different types and kinds of displays. The performance of the system was assessed in a series of workshops, which have provided insights to inform the development of future systems

    Mediated Spatial Narratives: Experiencing Archival Material and Shared Memories in Urban Space

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    In this paper we report on studies we conducted focusing on the use of Augmented Reality to annotate real sites with relevant archival content. This is an interdisciplinary study of novel interactive technologies and supportive platforms such as geolocation-navigation and contextual digital augmentation of archival material in public spaces. We involved community volunteers, experts and public in a participatory heritage initiative. We designed an experience that supported a multi-platform participation, via an online geo-tagging portal and a mixed reality navigational experience. In an iterative design process we explored the use and preference of mobile devices, the controlled design of digital content anchored to real sites and the use of AR to support urban narratives. We did this by conducting a series of user walkthroughs with recruited participants and workshops with local experts related to the case studies. In this paper we argue on the importance of situating urban experience of digital archives and stories in the actual locations of the events they represent as to better support immersion, enhance place experience and reinforce situated learning. Our work contributes to the design of hybrid spatialities and experiences in urban space that relate to local memory and culture

    Augmented Reality: What Motivates Late Millennials towards Fashion Mobile Apps?

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    Generation Z is expected to be a dominant demographic and economic group. Cyber-waviness, constant reliance on smart devices that allows them to be always connected are among some of their intrinsic characteristics. The combination of this reality with the ever-changing technological environment is compelling retailers to reshape their business strategies, to meet this group desires and expectations and to foster their engagement. Augmented reality (AR) is emerging as a technological solution that pleases both consumers and retailers. This paper aims to answer two main questions: (1) How does generation Z evaluate an AR experience? (2) Which attributes/benefits do they value or not during an AR experience? Drawing on a qualitative methodology – content analysis of 34 interviewees – we discuss six main dimensions the potential customer value of the relationship between them and AR experiences under retailer context.info:eu-repo/semantics/publishedVersio
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