1,436 research outputs found

    Are tiled display walls needed for astronomy?

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    Clustering commodity displays into a Tiled Display Wall (TDW) provides a cost-effective way to create an extremely high resolution display, capable of approaching the image sizes now gen- erated by modern astronomical instruments. Astronomers face the challenge of inspecting single large images, many similar images simultaneously, and heterogeneous but related content. Many research institutions have constructed TDWs on the basis that they will improve the scientific outcomes of astronomical imagery. We test this concept by presenting sample images to astronomers and non- astronomers using a standard desktop display (SDD) and a TDW. These samples include standard English words, wide field galaxy surveys and nebulae mosaics from the Hubble telescope. These experiments show that TDWs provide a better environment for searching for small targets in large images than SDDs. It also shows that astronomers tend to be better at searching images for targets than non-astronomers, both groups are generally better when employing physical navigation as opposed to virtual navigation, and that the combination of two non-astronomers using a TDW rivals the experience of a single astronomer. However, there is also a large distribution in aptitude amongst the participants and the nature of the content also plays a significant role is success.Comment: 19 pages, 15 figures, accepted for publication in PASA (Publications of the Astronomical Society of Australia

    A Comparison of Mobile Scanning to a Total Station Survey at the I-35 and IA 92 Interchange in Warren County, Iowa, August 15, 2012

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    The purpose of this project was to investigate the potential for collecting and using data from mobile terrestrial laser scanning (MTLS) technology that would reduce the need for traditional survey methods for the development of highway improvement projects at the Iowa Department of Transportation (Iowa DOT). The primary interest in investigating mobile scanning technology is to minimize the exposure of field surveyors to dangerous high volume traffic situations. Issues investigated were cost, timeframe, accuracy, contracting specifications, data capture extents, data extraction capabilities and data storage issues associated with mobile scanning. The project area selected for evaluation was the I-35/IA 92 interchange in Warren County, Iowa. This project covers approximately one mile of I-35, one mile of IA 92, 4 interchange ramps, and bridges within these limits. Delivered LAS and image files for this project totaled almost 31GB. There is nearly a 6-fold increase in the size of the scan data after post-processing. Camera data, when enabled, produced approximately 900MB of imagery data per mile using a 2- camera, 5 megapixel system. A comparison was done between 1823 points on the pavement that were surveyed by Iowa DOT staff using a total station and the same points generated through the MTLS process. The data acquired through the MTLS and data processing met the Iowa DOT specifications for engineering survey. A list of benefits and challenges is included in the detailed report. With the success of this project, it is anticipate[d] that additional projects will be scanned for the Iowa DOT for use in the development of highway improvement projects

    Computational performance analysis of Deep Learning using high resolution images with variable shapes

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    En este estudio analizo el proceso de entrenamiento de una red neural convolucional desde la perspectiva del rendimiento computacional. Mediante el uso de herramientas de instrumentación y métricas de eficiencia, voy a mostrar cómo se comporta este programa en un entorno de alta capacidad computacional usando distintos conjuntos de datos. Además, mostraré varios test de rendimiento relacionados con la escalabilidad de recursos y un estudio sobre cómo algunos parámetros de ejecución alteran los resultados.In this study I analyse the training process of a convolutional neural network from a computational performance perspective. By using instrumentation tools and efficiency metrics, I will show how this kind of programs behave in a high performance computing environment with different kinds of datasets. Also, I will show several performance tests regarding the resource scalability and a study of how execution parameters impact the results

    Development and Validation of a Smartphone Heart Rate Acquisition Application for Health Promotion and Wellness Telehealth Applications

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    Objective. Current generation smartphones' video camera technologies enable photoplethysmographic (PPG) acquisition and heart rate (HR) measurement. The study objective was to develop an Android application and compare HRs derived from a Motorola Droid to electrocardiograph (ECG) and Nonin 9560BT pulse oximeter readings during various movement-free tasks. Materials and Methods. HRs were collected simultaneously from 14 subjects, ages 20 to 58, healthy or with clinical conditions, using the 3 devices during 5-minute periods while at rest, reading aloud under observation, and playing a video game. Correlation between the 3 devices was determined, and Bland-Altman plots for all possible pairs of devices across all conditions assessed agreement. Results. Across conditions, all device pairs showed high correlations. Bland-Altman plots further revealed the Droid as a valid measure for HR acquisition. Across all conditions, the Droid compared to ECG, 95% of the data points (differences between devices) fell within the limits of agreement. Conclusion. The Android application provides valid HRs at varying levels of movement free mental/perceptual motor exertion. Lack of electrode patches or wireless sensor telemetric straps make it advantageous for use in mobile-cell-phone-delivered health promotion and wellness programs. Further validation is needed to determine its applicability while engaging in physical movement-related activities

    3D DIGITIZATION OF MUSEUM CONTENT WITHIN THE 3DICONS PROJECT

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    The main purpose of the European Project "3DIcons" is to digitize masterpieces of Cultural Heritage and provide the related 3D models and metadata to Europeana, an Internet portal that acts as an interface to millions of books, paintings, films, museum objects and archival records that have been digitised throughout Europe. The purpose of this paper is to define a complete pipeline which covers all technical and logistic aspects for creating 3D models in a Museum environment with no established digitization laboratory, from the 3D data acquisition to the creation of models that has to be searchable on the Internet through Europeana. The research group of Politecnico di Milano is dealing with the 3D modelling of the Archaeological Museum of Milan and most of its valuable content. In this paper an optimized 3D modelling pipeline is shown, that takes into account all the potential problems occurring during the survey and the related data processing. Most of the 3D digitization activity have been made exploiting the Structure From Motion (SfM) technique, handling all the acquisition (e.g. objects enlightenment, camera-object relative positioning, object shape and material, etc.) and processing problems (e.g. difficulties in the alignment step, model scaling, mesh optimization, etc.), but without neglecting the metric rigor of the results. This optimized process has been applied on a significant number of items, showing how this technique can allow large scale 3D digitization projects with relatively limited efforts
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