Computing and data processing

The applications of computers and data processing to astronomy are discussed. Among the topics covered are the emerging national information infrastructure, workstations and supercomputers, supertelescopes, digital astronomy, astrophysics in a numerical laboratory, community software, archiving of ground-based observations, dynamical simulations of complex systems, plasma astrophysics, and the remote control of fourth dimension supercomputers

Photographed Rapid HIV Test Results Pilot Novel Quality Assessment and Training Schemes

HIV rapid diagnostic tests (RDTs) are now used widely in non-laboratory settings by non-laboratory-trained operators. Quality assurance programmes are essential in ensuring the quality of HIV RDT outcomes. However, there is no cost-effective means of supplying the many operators of RDTs with suitable quality assurance schemes. Therefore, it was examined whether photograph-based RDT results could be used and correctly interpreted in the non-laboratory setting. Further it was investigated if a single training session improved the interpretation skills of RDT operators. The photographs were interpreted, a 10-minute tutorial given and then a second interpretation session was held. It was established that the results could be read with accuracy. The participants (n = 75) with a range of skills interpreted results (>80% concordance with reference results) from a panel of 10 samples (three negative and seven positive) using four RDTs. Differences in accuracy of interpretation before and after the tutorial were marked in some cases. Training was more effective for improving the accurate interpretation of more complex results, e.g. results with faint test lines or for multiple test lines, and especially for improving interpretation skills of inexperienced participants. It was demonstrated that interpretation of RDTs was improved using photographed results allied to a 10-minute training session. It is anticipated that this method could be used for training but also for quality assessment of RDT operators without access to conventional quality assurance or training schemes requiring wet samples

Heritage documentation techniques and methods

This methodology notebooks "Heritage documentation techniques and methods", contains • 3D modelling, digital photography and information dissemination • Creation of 3D models by using scanners • Low-cost desktop scanner • Photography notes: Exposure • Photography notes: Focal length, lenses and cross-polarization • White adjustment and colour calibration • Image-Based Modelling Systems • Focus stacking technique • Rollout photography and DStretch filter • Information dissemination • 3D diagram blocks • Simple animations of 3D modelsEsta serie de cuadernos tiene como objetivo difundir un conjunto de técnicas usadas principalmente para la construcción y documentación de modelos tridimensionales (3D) y fotografía de alta resolución de objetos arqueológicos. Estas técnicas posibilitan construir modelos con calidad métrica contrastada, color calibrado y alta resolución que se difunden por internet usando diversas plataformas.This series of notebooks aims to describe a set of techniques used mainly to construct and document the three-dimensional (3D) models and high-resolution photographs of archaeological objects. These techniques can be used to build models with a contrasting metric quality, calibrated colour and high resolution, to be disseminated on the Internet using various platforms and web services.Parte de la realización de estos cuadernos ha sido financiada a través del proyecto GR18028 (Grupo de investigación RNM026) el cual ha sido cofinanciado por los Fondos Europeos de Desarrollo Regional (FEDER) y el Gobierno de Extremadura

An intelligent interactive visual database management system for Space Shuttle closeout image management

Status is given of an applications investigation on the potential for using an expert system shell for classification and retrieval of high resolution, digital, color space shuttle closeout photography. This NASA funded activity has focused on the use of integrated information technologies to intelligently classify and retrieve still imagery from a large, electronically stored collection. A space shuttle processing problem is identified, a working prototype system is described, and commercial applications are identified. A conclusion reached is that the developed system has distinct advantages over the present manual system and cost efficiencies will result as the system is implemented. Further, commercial potential exists for this integrated technology

access: v.10, no.02, Summer 1996

published or submitted for publicatio

Study of time-lapse processing for dynamic hydrologic conditions

The usefulness of dynamic display techniques in exploiting the repetitive nature of ERTS imagery was investigated. A specially designed Electronic Satellite Image Analysis Console (ESIAC) was developed and employed to process data for seven ERTS principal investigators studying dynamic hydrological conditions for diverse applications. These applications include measurement of snowfield extent and sediment plumes from estuary discharge, Playa Lake inventory, and monitoring of phreatophyte and other vegetation changes. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The most unique feature of the system is the capability to time lapse the imagery and analytic displays of the imagery. Data products included quantitative measurements of distances and areas, binary thematic maps based on monospectral or multispectral decisions, radiance profiles, and movie loops. Applications of animation for uses other than creating time-lapse sequences are identified. Input to the ESIAC can be either digital or via photographic transparencies

Description and Experience of the Clinical Testbeds

This deliverable describes the up-to-date technical environment at three clinical testbed demonstrator sites of the 6WINIT Project, including the adapted clinical applications, project components and network transition technologies in use at these sites after 18 months of the Project. It also provides an interim description of early experiences with deployment and usage of these applications, components and technologies, and their clinical service impact

Colorimetric tolerances of digital images

An environment to derive colorimetric tolerances of images was established and an experiment using this new environment was performed. This environment allows for images to be digitally captured, colorimetrically manipulated, displayed, observed, and statistically evaluated. The visual experiment measured perceptibility and acceptability colorimetric tolerances for images using paired comparison techniques. Thirty-two observers judged six typical photographic scenes displayed on a high resolution color monitor. These scenes were manipulated using ten linear and nonlinear functions in the CIELAB dimensions of lightness, chroma, and hue angle. The tolerances were determined using probit analysis. It was found that scene content did not significantly affect the tolerances. The CIELAB, CMC, and MCSL color difference equations were shown to be inadequate for accurately modeling image tolerances. Finally, possible applications of this work are described

In vitro detection of mesio-buccal canals in maxillary molar cross-sections using three different resolutions with Kodak 9000 3D CBCT.

CBCT in endodontics demonstrates anatomic features in 3D that intraoral, panoramic, and cephalometric images cannot. CBCT units reconstruct the projection data to provide interrelational images in three orthogonal planes (axial, sagittal, and coronal). In addition because reconstruction of CBCT data is performed natively using a personal computer, data can be reoriented in their true spatial relationships. Aims: To investigate accurate detection of the correct number of root canals in the mesio-buccal root of the maxillary molar teeth using 3D imaging with cone beam computed tomography (CBCT) at different spatial resolution (isotropic voxel) settings. Methods: With IRB approval, 31 extracted maxillary molars were examined using high resolution, small field of view CBCT at isotropic voxel resolutions ranging at 0.076, 0.10 and 0.20 mm. The image data sets were imported into third party segmentation software to provide 3D videos for 8 observers to determine the number of mesio-buccal root canals in cross-sectional reconstructions. The ground truth was later established by sectioning the tooth roots axially. Results: Twenty-four of the teeth proved on sectioning to have two mesio-buccal canals whereas the others had one canal. Accuracy in detection of mesio-buccal canals varied between observers from 59% to 75% and statistically unrelated to observer experience. No statistical differences were found between the reconstructed 3D images regarding accurate detection of canals. Conclusions: CBCT outperformed the findings for accuracy in detection of mesio-buccal root canals in all previous studies using 2D imaging modalities and Tuned Aperture Computed Tomography. Keywords: Computed Tomography, X-ray, Cone-Beam; Endodontics; Image processing