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Sample records for instant stereoscopic tomography

  1. FIRST THREE-DIMENSIONAL RECONSTRUCTIONS OF CORONAL LOOPS WITH THE STEREO A+B SPACECRAFT. III. INSTANT STEREOSCOPIC TOMOGRAPHY OF ACTIVE REGIONS

    SciTech Connect

    Aschwanden, Markus J.; Wuelser, Jean-Pierre; Nitta, Nariaki V.; Lemen, James R.; Sandman, Anne

    2009-04-10

    Here we develop a novel three-dimensional (3D) reconstruction method of the coronal plasma of an active region by combining stereoscopic triangulation of loops with density and temperature modeling of coronal loops with a filling factor equivalent to tomographic volume rendering. Because this method requires only a stereoscopic image pair in multiple temperature filters, which are sampled within {approx}1 minute with the recent STEREO/EUVI instrument, this method is about four orders of magnitude faster than conventional solar rotation-based tomography. We reconstruct the 3D density and temperature distribution of active region NOAA 10955 by stereoscopic triangulation of 70 loops, which are used as a skeleton for a 3D field interpolation of some 7000 loop components, leading to a 3D model that reproduces the observed fluxes in each stereoscopic image pair with an accuracy of a few percents (of the average flux) in each pixel. With the stereoscopic tomography we infer also a differential emission measure distribution over the entire temperature range of T {approx} 10{sup 4}-10{sup 7}, with predictions for the transition region and hotter corona in soft X-rays. The tomographic 3D model provides also large statistics of physical parameters. We find that the extreme-ultraviolet loops with apex temperatures of T{sub m} {approx}< 3.0 MK tend to be super-hydrostatic, while hotter loops with T{sub m} {approx} 4-7 MK are near-hydrostatic. The new 3D reconstruction model is fully independent of any magnetic field data and is promising for future tests of theoretical magnetic field models and coronal heating models.

  2. Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography

    PubMed Central

    Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S.; Kuo, Anthony N.; Toth, Cynthia A.; Izatt, Joseph A.

    2016-01-01

    Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

  3. Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography.

    PubMed

    Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S; Kuo, Anthony N; Toth, Cynthia A; Izatt, Joseph A

    2016-05-01

    Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

  4. Reconstruction of soot temperature and volume fraction profiles of an asymmetric flame using stereoscopic tomography

    SciTech Connect

    Huang, Qun-xing; Wang, Fei; Liu, Dong; Ma, Zeng-yi; Yan, Jian-hua; Chi, Yong; Cen, Ke-fa

    2009-03-15

    The present study attempts to reconstruct soot temperature and volume fraction distributions for the asymmetric diffusive flame using a tomography technique. A high-resolution camera equipped with a stereo adapter was employed to capture stereoscopic flame images, which were used to obtain monochromatic line-of-sight flame emission projections within the visible range. A matrix-decomposition-based least squares algorithm was introduced to reconstruct the emission intensity distributions in the flame sections. The retrieved intensities were used to infer local soot temperature and volume fraction. Numerical assessments show that for soot volume fraction measurement, the system signal-to-noise ratio should be larger than 62.5 dB. The proposed tomography system was found to be capable of symmetric and asymmetric flame measurements. (author)

  5. Stereoscopic Vascular Models of the Head and Neck: A Computed Tomography Angiography Visualization

    ERIC Educational Resources Information Center

    Cui, Dongmei; Lynch, James C.; Smith, Andrew D.; Wilson, Timothy D.; Lehman, Michael N.

    2016-01-01

    Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching…

  6. Stereoscopic camera design

    NASA Astrophysics Data System (ADS)

    Montgomery, David J.; Jones, Christopher K.; Stewart, James N.; Smith, Alan

    2002-05-01

    It is clear from the literature that the majority of work in stereoscopic imaging is directed towards the development of modern stereoscopic displays. As costs come down, wider public interest in this technology is expected to increase. This new technology would require new methods of image formation. Advances in stereo computer graphics will of course lead to the creation of new stereo computer games, graphics in films etc. However, the consumer would also like to see real-world stereoscopic images, pictures of family, holiday snaps etc. Such scenery would have wide ranges of depth to accommodate and would need also to cope with moving objects, such as cars, and in particular other people. Thus, the consumer acceptance of auto/stereoscopic displays and 3D in general would be greatly enhanced by the existence of a quality stereoscopic camera. This paper will cover an analysis of existing stereoscopic camera designs and show that they can be categorized into four different types, with inherent advantages and disadvantages. A recommendation is then made with regard to 3D consumer still and video photography. The paper will go on to discuss this recommendation and describe its advantages and how it can be realized in practice.

  7. Stereoscopic Video Microscope

    NASA Astrophysics Data System (ADS)

    Butterfield, James F.

    1980-11-01

    The new electronic technology of three-dimensional video combined with the established. science of microscopy has created. a new instrument. the Stereoscopic Video Microscope. The specimen is illuminated so the stereoscopic objective lens focuses the stereo-pair of images side-by-side on the video camera's pick-up, tube. The resulting electronic signal can be enhanced, digitized, colorized, quantified, its polarity reverse., and its gray scale expanJed non-linearally. The signal can be transmitted over distances and can be stored on video. tape for later playback. The electronic signal is converted to a stereo-pair of visual images on the video monitor's cathode-ray-tube. A stereo-hood is used to fuse the two images for three-dimensional viewing. The conventional optical microscope has definite limitations, many of which can be eliminated by converting the optical image to an electronic signal in the video microscope. The principal aHvantages of the Stereoscopic Video Microscope compared to the conventional optical microscope are: great ease of viewing; group viewing; ability to easily recohd; and, the capability of processing the electronic signal for video. enhancement. The applications cover nearly all fields of microscopy. These include: microelectronics assembly, inspection, and research; biological, metallurgical, and che.illical research; and other industrial and medical uses. The Stereo-scopic Video Microscope is particularly useful for instructional and recordkeeping purposes. The video microscope can be monoscopic or three dimensional.

  8. Stereoscopic vision system

    NASA Astrophysics Data System (ADS)

    Király, Zsolt; Springer, George S.; Van Dam, Jacques

    2006-04-01

    In this investigation, an optical system is introduced for inspecting the interiors of confined spaces, such as the walls of containers, cavities, reservoirs, fuel tanks, pipelines, and the gastrointestinal tract. The optical system wirelessly transmits stereoscopic video to a computer that displays the video in realtime on the screen, where it is viewed with shutter glasses. To minimize space requirements, the videos from the two cameras (required to produce stereoscopic images) are multiplexed into a single stream for transmission. The video is demultiplexed inside the computer, corrected for fisheye distortion and lens misalignment, and cropped to the proper size. Algorithms are developed that enable the system to perform these tasks. A proof-of-concept device is constructed that demonstrates the operation and the practicality of the optical system. Using this device, tests are performed assessing validities of the concepts and the algorithms.

  9. Stereoscopic surface perception.

    PubMed

    Anderson, B L

    1999-12-01

    Physiological, computational, and psychophysical studies of stereopsis have assumed that the perceived surface structure of binocularly viewed images is primarily specified by the pattern of binocular disparities in the two eyes' views. A novel set of stereoscopic phenomena are reported that demonstrate the insufficiency of this view. It is shown that the visual system computes the contrast relationships along depth discontinuities to infer the depth, lightness, and opacity of stereoscopically viewed surfaces. A novel theoretical framework is introduced to explain these results. It is argued that the visual system contains mechanisms that enforce two principles of scene interpretation: a generic view principle that determines qualitative scene geometry, and anchoring principles that determine how image data are quantitatively partitioned between different surface attributes. PMID:10624955

  10. Stereoscopic optical viewing system

    DOEpatents

    Tallman, Clifford S.

    1987-01-01

    An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  11. Stereoscopic optical viewing system

    DOEpatents

    Tallman, C.S.

    1986-05-02

    An improved optical system which provides the operator with a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  12. SU-E-J-39: Comparison of PTV Margins Determined by In-Room Stereoscopic Image Guidance and by On-Board Cone Beam Computed Tomography Technique for Brain Radiotherapy Patients

    SciTech Connect

    Ganesh, T; Paul, S; Munshi, A; Sarkar, B; Krishnankutty, S; Sathya, J; George, S; Jassal, K; Roy, S; Mohanti, B

    2014-06-01

    Purpose: Stereoscopic in room kV image guidance is a faster tool in daily monitoring of patient positioning. Our centre, for the first time in the world, has integrated such a solution from BrainLAB (ExacTrac) with Elekta's volumetric cone beam computed tomography (XVI). Using van Herk's formula, we compared the planning target volume (PTV) margins calculated by both these systems for patients treated with brain radiotherapy. Methods: For a total of 24 patients who received partial or whole brain radiotherapy, verification images were acquired for 524 treatment sessions by XVI and for 334 sessions by ExacTrac out of the total 547 sessions. Systematic and random errors were calculated in cranio-caudal, lateral and antero-posterior directions for both techniques. PTV margins were then determined using van Herk formula. Results: In the cranio-caudal direction, systematic error, random error and the calculated PTV margin were found to be 0.13 cm, 0.12 cm and 0.41 cm with XVI and 0.14 cm, 0.13 cm and 0.44 cm with ExacTrac. The corresponding values in lateral direction were 0.13 cm 0.1 cm and 0.4 cm with XVI and 0.13 cm, 0.12 cm and 0.42 cm with ExacTrac imaging. The same parameters for antero-posterior were for 0.1 cm, 0.11 cm and 0.34 cm with XVI and 0.13 cm, 0.16 cm and 0.43 cm with ExacTrac imaging. The margins estimated with the two imaging modalities were comparable within ± 1 mm limit. Conclusion: Verification of setup errors in the major axes by two independent imaging systems showed the results are comparable and within ± 1 mm. This implies that planar imaging based ExacTrac can yield equal accuracy in setup error determination as the time consuming volumetric imaging which is considered as the gold standard. Accordingly PTV margins estimated by this faster imaging technique can be confidently used in clinical setup.

  13. Instant Messaging by SIP

    NASA Astrophysics Data System (ADS)

    Muhi, Daniel; Dulai, Tibor; Jaskó, Szilárd

    2008-11-01

    SIP is a general-purpose application layer protocol which is able to establish sessions between two or more parties. These sessions are mainly telephone calls and multimedia conferences. However it can be used for other purposes like instant messaging and presence service. SIP has a very important role in mobile communication as more and more communicating applications are going mobile. In this paper we would like to show how SIP can be used for instant messaging purposes.

  14. Stereoscopically Observing Manipulative Actions.

    PubMed

    Ferri, S; Pauwels, K; Rizzolatti, G; Orban, G A

    2016-08-01

    The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors "stimulus type" (action, static control, and dynamic control), "stereopsis" (present, absent) and "viewpoint" (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. PMID:27252350

  15. Stereoscopically Observing Manipulative Actions

    PubMed Central

    Ferri, S.; Pauwels, K.; Rizzolatti, G.; Orban, G. A.

    2016-01-01

    The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors “stimulus type” (action, static control, and dynamic control), “stereopsis” (present, absent) and “viewpoint” (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. PMID:27252350

  16. Saliency detection for stereoscopic images.

    PubMed

    Fang, Yuming; Wang, Junle; Narwaria, Manish; Le Callet, Patrick; Lin, Weisi

    2014-06-01

    Many saliency detection models for 2D images have been proposed for various multimedia processing applications during the past decades. Currently, the emerging applications of stereoscopic display require new saliency detection models for salient region extraction. Different from saliency detection for 2D images, the depth feature has to be taken into account in saliency detection for stereoscopic images. In this paper, we propose a novel stereoscopic saliency detection framework based on the feature contrast of color, luminance, texture, and depth. Four types of features, namely color, luminance, texture, and depth, are extracted from discrete cosine transform coefficients for feature contrast calculation. A Gaussian model of the spatial distance between image patches is adopted for consideration of local and global contrast calculation. Then, a new fusion method is designed to combine the feature maps to obtain the final saliency map for stereoscopic images. In addition, we adopt the center bias factor and human visual acuity, the important characteristics of the human visual system, to enhance the final saliency map for stereoscopic images. Experimental results on eye tracking databases show the superior performance of the proposed model over other existing methods.

  17. Instant Insanity II

    ERIC Educational Resources Information Center

    Richmond, Tom; Young, Aaron

    2013-01-01

    "Instant Insanity II" is a sliding mechanical puzzle whose solution requires the special alignment of 16 colored tiles. We count the number of solutions of the puzzle's classic challenge and show that the more difficult ultimate challenge has, up to row permutation, exactly two solutions, and further show that no…

  18. The Instant of Knowing.

    ERIC Educational Resources Information Center

    Jacobsen, Josephine

    This speech discusses some of the general problems and traits of a poet and some of the particular poetry-related events in the life of this particular author. Brief descriptions of a poet's functions and creative energies are given, and the instant of knowing is defined as that particular moment when poets remember in a fresh, exciting way…

  19. Grounding in Instant Messaging

    ERIC Educational Resources Information Center

    Fox Tree, Jean E.; Mayer, Sarah A.; Betts, Teresa E.

    2011-01-01

    In two experiments, we investigated predictions of the "collaborative theory of language use" (Clark, 1996) as applied to instant messaging (IM). This theory describes how the presence and absence of different grounding constraints causes people to interact differently across different communicative media (Clark & Brennan, 1991). In Study 1, we…

  20. A rendering approach for stereoscopic web pages

    NASA Astrophysics Data System (ADS)

    Zhang, Jianlong; Wang, Wenmin; Wang, Ronggang; Chen, Qinshui

    2014-03-01

    Web technology provides a relatively easy way to generate contents for us to recognize the world, and with the development of stereoscopic display technology, the stereoscopic devices will become much more popular. The combination of web technology and stereoscopic display technology will bring revolutionary visual effect. The Stereoscopic 3D (S3D) web pages, in which text, image and video may have different depth, can be displayed on stereoscopic display devices. This paper presents the approach about how to render two viewing S3D web pages including text, images, widgets: first, an algorithm should be developed in order to display stereoscopic elements like text, widgets by using 2D graphic library; second, a method should be presented to render stereoscopic web page based on current framework of the browser; third, a rough solution is invented to fix the problem that comes out in the method.

  1. Stereoscopic observations from meteorological satellites

    NASA Astrophysics Data System (ADS)

    Hasler, A. F.; Mack, R.; Negri, A.

    The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk et al. [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner et al. [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler et al. [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated. Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the

  2. Stereoscopic medical imaging collaboration system

    NASA Astrophysics Data System (ADS)

    Okuyama, Fumio; Hirano, Takenori; Nakabayasi, Yuusuke; Minoura, Hirohito; Tsuruoka, Shinji

    2007-02-01

    The computerization of the clinical record and the realization of the multimedia have brought improvement of the medical service in medical facilities. It is very important for the patients to obtain comprehensible informed consent. Therefore, the doctor should plainly explain the purpose and the content of the diagnoses and treatments for the patient. We propose and design a Telemedicine Imaging Collaboration System which presents a three dimensional medical image as X-ray CT, MRI with stereoscopic image by using virtual common information space and operating the image from a remote location. This system is composed of two personal computers, two 15 inches stereoscopic parallax barrier type LCD display (LL-151D, Sharp), one 1Gbps router and 1000base LAN cables. The software is composed of a DICOM format data transfer program, an operation program of the images, the communication program between two personal computers and a real time rendering program. Two identical images of 512×768 pixcels are displayed on two stereoscopic LCD display, and both images show an expansion, reduction by mouse operation. This system can offer a comprehensible three-dimensional image of the diseased part. Therefore, the doctor and the patient can easily understand it, depending on their needs.

  3. Comparison of stereoscopic technologies in various configurations

    NASA Astrophysics Data System (ADS)

    Fliegel, Karel; Vítek, Stanislav; Jindra, Tomáš; Páta, Petr; Klíma, Miloš

    2012-10-01

    The aim of this paper is twofold. In the first part of the paper we present results of subjective quality assessment based comparison of stereoscopic technologies in various configurations. Subjective assessment has been done on a limited set of observers while using a database of stereoscopic test videos of various source types. There is also comparison of results obtained with the same stereoscopic content from the two cooperating test laboratories. The results can be used to address different aspects of viewing experience, especially comparing passive and active stereoscopic display technologies. The second part of the paper is focused on preliminary experimental results analyzing the vergence-accommodation conflict present in current stereoscopic systems. Simultaneous measurement of the vergence and accommodation has been done with observers viewing a real scene and its stereoscopic reproduction.

  4. A stereoscopic lens for digital cinema cameras

    NASA Astrophysics Data System (ADS)

    Lipton, Lenny; Rupkalvis, John

    2015-03-01

    Live-action stereoscopic feature films are, for the most part, produced using a costly post-production process to convert planar cinematography into stereo-pair images and are only occasionally shot stereoscopically using bulky dual-cameras that are adaptations of the Ramsdell rig. The stereoscopic lens design described here might very well encourage more live-action image capture because it uses standard digital cinema cameras and workflow to save time and money.

  5. Stereoscopic game design and evaluation

    NASA Astrophysics Data System (ADS)

    Rivett, Joe; Holliman, Nicolas

    2013-03-01

    We report on a new game design where the goal is to make the stereoscopic depth cue sufficiently critical to success that game play should become impossible without using a stereoscopic 3D (S3D) display and, at the same time, we investigate whether S3D game play is affected by screen size. Before we detail our new game design we review previously unreported results from our stereoscopic game research over the last ten years at the Durham Visualisation Laboratory. This demonstrates that game players can achieve significantly higher scores using S3D displays when depth judgements are an integral part of the game. Method: We design a game where almost all depth cues, apart from the binocular cue, are removed. The aim of the game is to steer a spaceship through a series of oncoming hoops where the viewpoint of the game player is from above, with the hoops moving right to left across the screen towards the spaceship, to play the game it is essential to make decisive depth judgments to steer the spaceship through each oncoming hoop. To confound these judgements we design altered depth cues, for example perspective is reduced as a cue by varying the hoop's depth, radius and cross-sectional size. Results: Players were screened for stereoscopic vision, given a short practice session, and then played the game in both 2D and S3D modes on a seventeen inch desktop display, on average participants achieved a more than three times higher score in S3D than they achieved in 2D. The same experiment was repeated using a four metre S3D projection screen and similar results were found. Conclusions: Our conclusion is that games that use the binocular depth cue in decisive game judgements can benefit significantly from using an S3D display. Based on both our current and previous results we additionally conclude that display size, from cell-phone, to desktop, to projection display does not adversely affect player performance.

  6. Marking spatial parts within stereoscopic video images

    NASA Astrophysics Data System (ADS)

    Belz, Constance; Boehm, Klaus; Duong, Thanh; Kuehn, Volker; Weber, Martin

    1996-04-01

    The technology of stereoscopic imaging enables reliable online telediagnoses. Applications of telediagnosis include the fields of medicine and in general telerobotics. For allowing the participants in a telediagnosis to mark spatial parts within the stereoscopic video image, graphic tools and automatism have to be provided. The process of marking spatial parts and objects inside a stereoscopic video image is a non trivial interaction technique. The markings themselves have to be 3D elements instead of 2D markings which would lead to an alienated effect `in' the stereoscopic video image. Furthermore, one problem to be tackled here, is that the content of the stereoscopic video image is unknown. This is in contrast to 3D Virtual Reality scenes, which enable an easy 3D interaction because all the objects and their position within the 3D scene are known. The goals of our research comprised the development of new interaction paradigms and marking techniques in stereoscopic video images, as well as an investigation of input devices appropriate for this interaction task. We have implemented these interaction techniques in a test environment and integrated therefore computer graphics into stereoscopic video images. In order to evaluate the new interaction techniques a user test was carried out. The results of our research will be presented here.

  7. Subjective image position in stereoscopic TV systems: considerations on comfortable stereoscopic images

    NASA Astrophysics Data System (ADS)

    Mitsuhashi, Tetsuo

    1994-05-01

    In stereoscopic picture systems, the image should be reproduced in a psychologically proper position that allows comfortable stereoscopic perception. Position matching in observer space between the stereoscopic image and a small marker was successfully adopted to measure the subjective image position. The subjective image position was measured for geometric figures and actual scenes while varying the resolution, contrast, brightness, and color between the L- and R-pictures. The image moves closer to the screen in proportion to the increase in resolution difference. A pair of color and darker monochrome pictures can reproduce acceptable stereoscopic images without conspicuous color rivalry. Mental fatigue is also an important factor in comfortable stereoscopic image viewing. The CFF is discussed together with other factors such as accommodation characteristics, picture quality, and viewing conditions that relate to future stereoscopic TV systems that allow comfortable viewing.

  8. Depth Perception In Remote Stereoscopic Viewing Systems

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.; Von Sydow, Marika

    1989-01-01

    Report describes theoretical and experimental studies of perception of depth by human operators through stereoscopic video systems. Purpose of such studies to optimize dual-camera configurations used to view workspaces of remote manipulators at distances of 1 to 3 m from cameras. According to analysis, static stereoscopic depth distortion decreased, without decreasing stereoscopitc depth resolution, by increasing camera-to-object and intercamera distances and camera focal length. Further predicts dynamic stereoscopic depth distortion reduced by rotating cameras around center of circle passing through point of convergence of viewing axes and first nodal points of two camera lenses.

  9. Stereoscopic desktop VR system for telemaintenance

    NASA Astrophysics Data System (ADS)

    Kleiber, Michael; Weltjen, Bastian; Förster, Julia

    2012-03-01

    Tele-cooperation for maintenance is usually supported by synchronous audio but only asynchronous video exchange when only limited bandwidth is available. We present an alternative approach for such a collaborative maintenance task. By utilizing techniques and technologies from Augmented Reality (AR) applications our approach can provide a synchronous shared visual context for the collaborators without a direct video link but through a Desktop VR system. To increase the spatial presence of the remote expert we employ stereoscopic displays. The effectiveness of a stereoscopic 3D system for orientation and localization was evaluated in an abstract experiment. In a more practical experiment the stereoscopic VR system was also evaluated by automobile mechanics. The benefits of stereoscopic Desktop VR systems were shown in both experiments.

  10. Binocular coordination in response to stereoscopic stimuli

    NASA Astrophysics Data System (ADS)

    Liversedge, Simon P.; Holliman, Nicolas S.; Blythe, Hazel I.

    2009-02-01

    Humans actively explore their visual environment by moving their eyes. Precise coordination of the eyes during visual scanning underlies the experience of a unified perceptual representation and is important for the perception of depth. We report data from three psychological experiments investigating human binocular coordination during visual processing of stereoscopic stimuli.In the first experiment participants were required to read sentences that contained a stereoscopically presented target word. Half of the word was presented exclusively to one eye and half exclusively to the other eye. Eye movements were recorded and showed that saccadic targeting was uninfluenced by the stereoscopic presentation, strongly suggesting that complementary retinal stimuli are perceived as a single, unified input prior to saccade initiation. In a second eye movement experiment we presented words stereoscopically to measure Panum's Fusional Area for linguistic stimuli. In the final experiment we compared binocular coordination during saccades between simple dot stimuli under 2D, stereoscopic 3D and real 3D viewing conditions. Results showed that depth appropriate vergence movements were made during saccades and fixations to real 3D stimuli, but only during fixations on stereoscopic 3D stimuli. 2D stimuli did not induce depth vergence movements. Together, these experiments indicate that stereoscopic visual stimuli are fused when they fall within Panum's Fusional Area, and that saccade metrics are computed on the basis of a unified percept. Also, there is sensitivity to non-foveal retinal disparity in real 3D stimuli, but not in stereoscopic 3D stimuli, and the system responsible for binocular coordination responds to this during saccades as well as fixations.

  11. Crosstalk in stereoscopic displays: a review

    NASA Astrophysics Data System (ADS)

    Woods, Andrew J.

    2012-10-01

    Crosstalk, also known as ghosting or leakage, is a primary factor in determining the image quality of stereoscopic three dimensional (3D) displays. In a stereoscopic display, a separate perspective view is presented to each of the observer's two eyes in order to experience a 3D image with depth sensation. When crosstalk is present in a stereoscopic display, each eye will see a combination of the image intended for that eye, and some of the image intended for the other eye-making the image look doubled or ghosted. High levels of crosstalk can make stereoscopic images hard to fuse and lack fidelity, so it is important to achieve low levels of crosstalk in the development of high-quality stereoscopic displays. Descriptive and mathematical definitions of these terms are formalized and summarized. The mechanisms by which crosstalk occurs in different stereoscopic display technologies are also reviewed, including micropol 3D liquid crystal displays (LCDs), autostereoscopic (lenticular and parallax barrier), polarized projection, anaglyph, and time-sequential 3D on LCDs, plasma display panels and cathode ray tubes. Crosstalk reduction and crosstalk cancellation are also discussed along with methods of measuring and simulating crosstalk.

  12. Statis omnidirectional stereoscopic display system

    NASA Astrophysics Data System (ADS)

    Barton, George G.; Feldman, Sidney; Beckstead, Jeffrey A.

    1999-11-01

    A unique three camera stereoscopic omnidirectional viewing system based on the periscopic panoramic camera described in the 11/98 SPIE proceedings (AM13). The 3 panoramic cameras are equilaterally combined so each leg of the triangle approximates the human inter-ocular spacing allowing each panoramic camera to view 240 degree(s) of the panoramic scene, the most counter clockwise 120 degree(s) being the left eye field and the other 120 degree(s) segment being the right eye field. Field definition may be by green/red filtration or time discrimination of the video signal. In the first instance a 2 color spectacle is used in viewing the display or in the 2nd instance LCD goggles are used to differentiate the R/L fields. Radially scanned vidicons or re-mapped CCDs may be used. The display consists of three vertically stacked 120 degree(s) segments of the panoramic field of view with 2 fields/frame. Field A being the left eye display and Field B the right eye display.

  13. Stereoscopic video compression using temporal scalability

    NASA Astrophysics Data System (ADS)

    Puri, Atul; Kollarits, Richard V.; Haskell, Barry G.

    1995-04-01

    Despite the fact that human ability to perceive a high degree of realism is directly related to our ability to perceive depth accurately in a scene, most of the commonly used imaging and display technologies are able to provide only a 2D rendering of the 3D real world. Many current as well as emerging applications in areas of entertainment, remote operations, industrial and medicine can benefit from the depth perception offered by stereoscopic video systems which employ two views of a scene imaged under the constraints imposed by human visual system. Among the many challenges to be overcome for practical realization and widespread use of 3D/stereoscopic systems are efficient techniques for digital compression of enormous amounts of data while maintaining compatibility with normal video decoding and display systems. After a brief discussion on the relationship of digital stereoscopic 3DTV with digital TV and HDTV, we present an overview of tools in the MPEG-2 video standard that are relevant to our discussion on compression of stereoscopic video, which is the main topic of this paper. Next, we determine ways in which temporal scalability concepts can be applied to exploit redundancies inherent between the two views of a scene comprising stereoscopic video. Due consideration is given to masking properties of stereoscopic vision to determine bandwidth partitioning between the two views to realize an efficient coding scheme while providing sufficient quality. Simulations are performed on stereoscopic video of normal TV resolution to compare the performance of the two temporal scalability configurations with each other and with the simulcast solution. Preliminary results are quite promising and indicate that the configuration that exploits motion and disparity compensation significantly outperforms the one that exploits disparity compensation alone. Compression of both views of stereo video of normal TV resolution appears feasible in a total of 8 or 9 Mbit/s. Finally

  14. Consciousness and stereoscopic environmental imaging

    NASA Astrophysics Data System (ADS)

    Mason, Steve

    2014-02-01

    The question of human consciousness has intrigued philosophers and scientists for centuries: its nature, how we perceive our environment, how we think, our very awareness of thought and self. It has been suggested that stereoscopic vision is "a paradigm of how the mind works" 1 In depth perception, laws of perspective are known, reasoned, committed to memory from an early age; stereopsis, on the other hand, is a 3D experience governed by strict laws but actively joined within the brain―one sees it without explanation. How do we, in fact, process two different images into one 3D module within the mind and does an awareness of this process give us insight into the workings of our own consciousness? To translate this idea to imaging I employed ChromaDepth™ 3D glasses that rely on light being refracted in a different direction for each eye―colors of differing wavelengths appearing at varying distances from the viewer resulting in a 3D space. This involves neither calculation nor manufacture of two images or views. Environmental spatial imaging was developed―a 3D image was generated that literally surrounds the viewer. The image was printed and adhered to a semi-circular mount; the viewer then entered the interior to experience colored shapes suspended in a 3D space with an apparent loss of surface, or picture plane, upon which the image is rendered. By focusing our awareness through perception-based imaging we are able to gain a deeper understanding of how the brain works, how we see.

  15. History of polarized image stereoscopic display

    NASA Astrophysics Data System (ADS)

    Walworth, Vivian K.

    2013-03-01

    Stereoscopic photography became popular soon after the introduction of photographic processes by Daguerre and by Talbot in 1839. Stereoscopic images were most often viewed as side-by-side left- and right-eye image pairs, using viewers with prisms or mirrors. Superimposition of encoded image pairs was envisioned as early as the 1890s, and encoding by polarization first became practical in the 1930s with the introduction of polarizers in large sheet form. The use of polarizing filters enabled projection of stereoscopic image pairs and viewing of the projected image through complementary polarizing glasses. Further advances included the formation of images that were themselves polarizers, forming superimposed image pairs on a common carrier, the utilization of polarizing image dyes, the introduction of micropolarizers, and the utilization of liquid crystal polarizers.

  16. Shifting Of Image Fields For Better Stereoscopic TV Images

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.

    1988-01-01

    Concept for shifting horizontal positions of TV image fields of stereoscopic TV display reduces stereoscopic depth distorting while increasing stereoscopic depth resolution of images. Applicable to form of stereoscopic TV in which two views of scene presented by two video cameras to different fields of one monitor. According to concept, view of left camera shifts to left, and right camera, to right. Images made to overlap, so observed comfortably. Shifting done by inexpensive electronic circuitry.

  17. 21 CFR 886.1880 - Fusion and stereoscopic target.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing...

  18. 21 CFR 886.1880 - Fusion and stereoscopic target.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing...

  19. 21 CFR 886.1880 - Fusion and stereoscopic target.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing...

  20. 21 CFR 886.1880 - Fusion and stereoscopic target.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing...

  1. 21 CFR 886.1880 - Fusion and stereoscopic target.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing...

  2. Stereoscopic wide field of view imaging system

    NASA Technical Reports Server (NTRS)

    Prechtl, Eric F. (Inventor); Sedwick, Raymond J. (Inventor); Jonas, Eric M. (Inventor)

    2011-01-01

    A stereoscopic imaging system incorporates a plurality of imaging devices or cameras to generate a high resolution, wide field of view image database from which images can be combined in real time to provide wide field of view or panoramic or omni-directional still or video images.

  3. Stereoscopic display in a slot machine

    NASA Astrophysics Data System (ADS)

    Laakso, M.

    2012-03-01

    This paper reports the results of a user trial with a slot machine equipped with a stereoscopic display. The main research question was to find out what kind of added value does stereoscopic 3D (S-3D) bring to slot games? After a thorough literature survey, a novel gaming platform was designed and implemented. Existing multi-game slot machine "Nova" was converted to "3DNova" by replacing the monitor with an S-3D display and converting six original games to S-3D format. To evaluate the system, several 3DNova machines were put available for players for four months. Both qualitative and quantitative analysis was carried out from statistical values, questionnaires and observations. According to the results, people find the S-3D concept interesting but the technology is not optimal yet. Young adults and adults were fascinated by the system, older people were more cautious. Especially the need to wear stereoscopic glasses provide a challenge; ultimate system would probably use autostereoscopic technology. Also the games should be designed to utilize its full power. The main contributions of this paper are lessons learned from creating an S-3D slot machine platform and novel information about human factors related to stereoscopic slot machine gaming.

  4. Using stereoscopic imaging for visualization applications

    SciTech Connect

    Adelson, S.J.

    1994-02-01

    The purpose of scientific visualization is to simplify the analysis of numerical data by rendering the information as an image. Even when the image is familiar, as in the case of terrain data, preconceptions about what the image should look like and deceptive image artifacts can create misconceptions about what information is actually contained in the scene. One way of aiding the development of unambiguous visualizations is to add stereoscopic depth to the image. Despite the recent proliferation of affordable stereoscopic viewing equipment, few researchers are at this time taking advantage of stereo in their visualizations. It is generally perceived that the rendering time will have to be doubled in order to generate the pair, and so stereoscopic viewing is sacrificed in the name of expedient rendering. We show that this perception is often invalid. The second half of a stereoscopic image can be generated from the first half for a fraction of the computational cost of complete rendering, usually no more than 50% of the cost and in many cases as little as 5%. Using the techniques presented here, the benefits of stereoscopy can be added to existing visualization systems for only a small cost over current single-frame rendering methods.

  5. Monitor selection criteria for stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Meyer, Lhary

    1992-06-01

    Existing high-resolution monitors are optimized for display of non-stereoscopic images with field refresh rates of 60 to 80 hertz. Almost all existing graphics systems utilize refresh rates in this range. Stereoscopic field-sequential displays present alternate left and right images, with each eye seeing half the displayed fields by use of electronic shuttering systems. This image selection is accomplished by optical shutters that are alternately clear and opaque operating synchronously with the display. To maintain flicker-free display for each eye requires at least the doubling of the existing field rate. An idealized monitor for stereoscopic display adds several new demands on the performance of monitors that extend beyond existing requirements. Some of the new requirements may be contrary to existing needs, calling for engineering compromises to be considered. The paper addresses the electronic and perceptual requirements of stereoscopic monitors in the areas of scan ranges, phosphors, and interfaces. Success in utilizing existing commercial monitors and projectors and possible future directions are discussed.

  6. Light polarization in support of stereoscopic display

    NASA Astrophysics Data System (ADS)

    Walworth, Vivian K.

    2012-02-01

    The encoding of three-dimensional image pairs by polarization was proposed as early as the 1890s, perhaps stimulated by the popularity of stereoscopic photography, the proliferation of devices for viewing side-by-side stereoscopic images, and the invention of the anaglyph. The introduction of inexpensive sheet polarizing material gave rise to new three-dimensional technologies, starting in the 1930s with 16-mm black-and-white motion pictures projected by paired projectors equipped with orthogonally oriented polarizing filters. Further advances included the introduction of color, the concept of printing left- and right-eye images on a common carrier, and most recently the development of digital photography and the utilization of polarizers in both two- and three-dimensional digital color display.

  7. Stereoscopic surround displays using interference filters

    NASA Astrophysics Data System (ADS)

    Peikert, Silvio; Gerhardt, Jérémie

    2012-03-01

    To achieve stereoscopy on surround displays interference filters have some advantages over other techniques. However these filters introduce strong color differences between the projectors, which may reveal that the display is compound by multiple projectors. This article presents methods for a computationally efficient correction of the colorimetric properties of multi-projector surround displays. This correction is based on automated measurements by multiple cameras and a spectrometer. The described methods were validated by applying them to a stereoscopic dome display made up of 16 high definition projectors equipped with Infitec filters. On that display we achieved a significant improvement of the colorimetric properties compared to regular soft-edge blending. Our reference setup shows that the multi-projector approach combined with interference filters allows to build highly immersive stereoscopic surround displays fulfilling today's requirements on spatial resolution, frame rates and interaction latencies.

  8. Generating Stereoscopic Television Images With One Camera

    NASA Technical Reports Server (NTRS)

    Coan, Paul P.

    1996-01-01

    Straightforward technique for generating stereoscopic television images involves use of single television camera translated laterally between left- and right-eye positions. Camera acquires one of images (left- or right-eye image), and video signal from image delayed while camera translated to position where it acquires other image. Length of delay chosen so both images displayed simultaneously or as nearly simultaneously as necessary to obtain stereoscopic effect. Technique amenable to zooming in on small areas within broad scenes. Potential applications include three-dimensional viewing of geological features and meteorological events from spacecraft and aircraft, inspection of workpieces moving along conveyor belts, and aiding ground and water search-and-rescue operations. Also used to generate and display imagery for public education and general information, and possible for medical purposes.

  9. Stereoscopic Vision System For Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Matthies, Larry H.; Anderson, Charles H.

    1993-01-01

    Distances estimated from images by cross-correlation. Two-camera stereoscopic vision system with onboard processing of image data developed for use in guiding robotic vehicle semiautonomously. Combination of semiautonomous guidance and teleoperation useful in remote and/or hazardous operations, including clean-up of toxic wastes, exploration of dangerous terrain on Earth and other planets, and delivery of materials in factories where unexpected hazards or obstacles can arise.

  10. Birth in an Ordinary Instant

    PubMed Central

    De Vries, Charlotte

    2010-01-01

    Our daily lives are a series of ordinary moments and unnoticed thresholds—times that define us in ways we often do not give much attention. While we consider childbirth to be one of life's extra-ordinary events, the hours of labor and birth need not be dramatic (or traumatic) ones. I describe a quiet, well-supported birth in the Netherlands that is cause for celebration of the beauty of an ordinary instant that can define and enrich the human experience. PMID:21629383

  11. Usability of stereoscopic view in teleoperation

    NASA Astrophysics Data System (ADS)

    Boonsuk, Wutthigrai

    2015-03-01

    Recently, there are tremendous growths in the area of 3D stereoscopic visualization. The 3D stereoscopic visualization technology has been used in a growing number of consumer products such as the 3D televisions and the 3D glasses for gaming systems. This technology refers to the idea that human brain develops depth of perception by retrieving information from the two eyes. Our brain combines the left and right images on the retinas and extracts depth information. Therefore, viewing two video images taken at slightly distance apart as shown in Figure 1 can create illusion of depth [8]. Proponents of this technology argue that the stereo view of 3D visualization increases user immersion and performance as more information is gained through the 3D vision as compare to the 2D view. However, it is still uncertain if additional information gained from the 3D stereoscopic visualization can actually improve user performance in real world situations such as in the case of teleoperation.

  12. Recognition of stereoscopic images among elderly people

    NASA Astrophysics Data System (ADS)

    Omori, Masako; Watanabe, Tomoyuki; Miyao, Masaru; Sato, Yuzo; Ishihara, Shin-fya

    2002-06-01

    We tested 130 subjects including elderly people using two types of stereogram. One was a 3D image of a repeating parallel pattern showing balloons, from a software program called Stretch Eye. This program adopts a shift method in which the balloons diverge just at the point that causes a single shift between the right and left eyes, so that they appear to be more distant than the monitor screen. The Stretch Eye image was shown on a color LCD. The other image was a paper stereogram. Both used the same image of balloons. Using these 2 types of 3D image, we analyzed the recognition of stereoscopic images among elderly people. The subjects were 130 people aged 18 to 86 years, including 60 people over 60 years of age. The subjects' visual functions of cataract cloudiness (CC) and pupil distance were measured. Comparisons were carried out for the two targets of the paper stereograms and color LCDs. Subjects were divided into four groups according to the severity of CC. Two-way ANOVA was used for the statistical analysis in order to compare the influence of the target types, age and cataract cloudiness on the ability, distance and time of stereoscopic recognition. In a two-way ANOVA, two kinds of dependant variables, recognized speed (RS) and recognized distance (RD) were used for the subjects' stereoscopic recognition performance.

  13. Analysis of physiological impact while reading stereoscopic radiographs

    NASA Astrophysics Data System (ADS)

    Unno, Yasuko Y.; Tajima, Takashi; Kuwabara, Takao; Hasegawa, Akira; Natsui, Nobutaka; Ishikawa, Kazuo; Hatada, Toyohiko

    2011-03-01

    A stereoscopic viewing technology is expected to improve diagnostic performance in terms of reading efficiency by adding one more dimension to the conventional 2D images. Although a stereoscopic technology has been applied to many different field including TV, movies and medical applications, physiological fatigue through reading stereoscopic radiographs has been concerned although no established physiological fatigue data have been provided. In this study, we measured the α-amylase concentration in saliva, heart rates and normalized tissue hemoglobin index (nTHI) in blood of frontal area to estimate physiological fatigue through reading both stereoscopic radiographs and the conventional 2D radiographs. In addition, subjective assessments were also performed. As a result, the pupil contraction occurred just after the reading of the stereoscopic images, but the subjective assessments regarding visual fatigue were nearly identical for the reading the conventional 2D and stereoscopic radiographs. The α-amylase concentration and the nTHI continued to decline while examinees read both 2D and stereoscopic images, which reflected the result of subjective assessment that almost half of the examinees reported to feel sleepy after reading. The subjective assessments regarding brain fatigue showed that there were little differences between 2D and stereoscopic reading. In summary, this study shows that the physiological fatigue caused by stereoscopic reading is equivalent to the conventional 2D reading including ocular fatigue and burden imposed on brain.

  14. Analysis of individual variability and habituation in stereoscopic radiography

    NASA Astrophysics Data System (ADS)

    Unno, Yasuko Y.; Kuwabara, Takao; Uzenoff, Robert A.; Natsui, Nobutaka; Ishikawa, Kazuo

    2013-03-01

    In our previous stereoscopic image for medical use research, we reported that observers found it is easier to identify target objects in stereoscopic images than in two dimensional images, however, we found that mental and visual fatigue levels are equivalent in viewing the stereoscopic and the two dimensional images. We reported that a number of users dislike the sensations accompanying stereoscopic vision. Hence, we studied personal variation of stereoscopic visibility and the training effect for the stereoscopic visibility in this research. Simulated images, in which prepared calcifications were arranged at parallactic angles between +/-2° to +/-15° at object heights from 40 to 80mm, were displayed on a stereoscopic 3D display. Seven observers were selected to judge the achievement of stereoscopic vision (stereopsis) and their visibility was determined. The observers were asked to point the stereoscopic cursor of the 3D mammography viewer at the simulated calcifications and the accuracy rates were determined. Subsequently, re-examination was implemented after 3D visual training for 15 to 20 minutes per day for two weeks, and the visibility and accuracy rates were measured again. We found individual differences in the parallactic angles at which stereopsis was realized. Moreover, the parallactic angles of stereopsis widened through training and the average visibility improved from 69% to 84% as the result of training. Furthermore, the average accuracy rates improved from 53% to 60% the accuracy of depth commands improved. This suggests that observers who are weak in stereoscopic vision can be trained to be better at stereoscopic viewing.

  15. Enhancing Students' Learning: Instant Feedback Cards

    ERIC Educational Resources Information Center

    Mohrweis, Lawrence C.; Shinham, Kathe M.

    2015-01-01

    This study illustrates an active learning approach using instant feedback cards in the first course in accounting. The objectives of this study are to (1) describe instant feedback cards and (2) show how this tool, when used in an active learning environment, can enhance learning. We examined whether students exposed to immediate feedback…

  16. Instant Messaging in Dental Education.

    PubMed

    Khatoon, Binish; Hill, Kirsty B; Walmsley, A Damien

    2015-12-01

    Instant messaging (IM) is when users communicate instantly via their mobile devices, and it has become one of the most preferred choices of tools to communicate amongst health professions students. The aim of this study was to understand how dental students communicate via IM, faculty members' perspectives on using IM to communicate with students, and whether such tools are useful in the learning environment. After free-associating themes on online communication, two draft topic guides for structured interviews were designed that focussed on mobile device-related communication activities. A total of 20 students and six faculty members at the University of Birmingham School of Dentistry agreed to take part in the interviews. Students were selected from years 1-5 representing each year group. The most preferred communication tools were emails, social networking, and IM. Emails were used for more formal messages, and IM and social networking sites were used for shorter messages. WhatsApp was the most used IM app because of its popular features such as being able to check if recipients have read and received messages and group work. The students reported that changes were necessary to improve their communication with faculty members. The faculty members reported having mixed feelings toward the use of IM to communicate with students. The students wished to make such tools a permanent part of their learning environment, but only with the approval of faculty members. The faculty members were willing to accept IM as a communication tool only if it is monitored and maintained by the university and has a positive effect on learning. PMID:26632303

  17. Instant Messaging in Dental Education.

    PubMed

    Khatoon, Binish; Hill, Kirsty B; Walmsley, A Damien

    2015-12-01

    Instant messaging (IM) is when users communicate instantly via their mobile devices, and it has become one of the most preferred choices of tools to communicate amongst health professions students. The aim of this study was to understand how dental students communicate via IM, faculty members' perspectives on using IM to communicate with students, and whether such tools are useful in the learning environment. After free-associating themes on online communication, two draft topic guides for structured interviews were designed that focussed on mobile device-related communication activities. A total of 20 students and six faculty members at the University of Birmingham School of Dentistry agreed to take part in the interviews. Students were selected from years 1-5 representing each year group. The most preferred communication tools were emails, social networking, and IM. Emails were used for more formal messages, and IM and social networking sites were used for shorter messages. WhatsApp was the most used IM app because of its popular features such as being able to check if recipients have read and received messages and group work. The students reported that changes were necessary to improve their communication with faculty members. The faculty members reported having mixed feelings toward the use of IM to communicate with students. The students wished to make such tools a permanent part of their learning environment, but only with the approval of faculty members. The faculty members were willing to accept IM as a communication tool only if it is monitored and maintained by the university and has a positive effect on learning.

  18. Digital stereoscopic cinema: the 21st century

    NASA Astrophysics Data System (ADS)

    Lipton, Lenny

    2008-02-01

    Over 1000 theaters in more than a dozen countries have been outfitted with digital projectors using the Texas Instruments DLP engine equipped to show field-sequential 3-D movies using the polarized method of image selection. Shuttering eyewear and advanced anaglyph products are also being deployed for image selection. Many studios are in production with stereoscopic films, and some have committed to producing their entire output of animated features in 3-D. This is a time of technology change for the motion picture industry.

  19. Using a high-definition stereoscopic video system to teach microscopic surgery

    NASA Astrophysics Data System (ADS)

    Ilgner, Justus; Park, Jonas Jae-Hyun; Labbé, Daniel; Westhofen, Martin

    2007-02-01

    Introduction: While there is an increasing demand for minimally invasive operative techniques in Ear, Nose and Throat surgery, these operations are difficult to learn for junior doctors and demanding to supervise for experienced surgeons. The motivation for this study was to integrate high-definition (HD) stereoscopic video monitoring in microscopic surgery in order to facilitate teaching interaction between senior and junior surgeon. Material and methods: We attached a 1280x1024 HD stereo camera (TrueVisionSystems TM Inc., Santa Barbara, CA, USA) to an operating microscope (Zeiss ProMagis, Zeiss Co., Oberkochen, Germany), whose images were processed online by a PC workstation consisting of a dual Intel® Xeon® CPU (Intel Co., Santa Clara, CA). The live image was displayed by two LCD projectors @ 1280x768 pixels on a 1,25m rear-projection screen by polarized filters. While the junior surgeon performed the surgical procedure based on the displayed stereoscopic image, all other participants (senior surgeon, nurse and medical students) shared the same stereoscopic image from the screen. Results: With the basic setup being performed only once on the day before surgery, fine adjustments required about 10 minutes extra during the operation schedule, which fitted into the time interval between patients and thus did not prolong operation times. As all relevant features of the operative field were demonstrated on one large screen, four major effects were obtained: A) Stereoscopy facilitated orientation for the junior surgeon as well as for medical students. B) The stereoscopic image served as an unequivocal guide for the senior surgeon to demonstrate the next surgical steps to the junior colleague. C) The theatre nurse shared the same image, anticipating the next instruments which were needed. D) Medical students instantly share the information given by all staff and the image, thus avoiding the need for an extra teaching session. Conclusion: High definition

  20. Stereoscopic visual fatigue assessment and modeling

    NASA Astrophysics Data System (ADS)

    Wang, Danli; Wang, Tingting; Gong, Yue

    2014-03-01

    Evaluation of stereoscopic visual fatigue is one of the focuses in the user experience research. It is measured in either subjective or objective methods. Objective measures are more preferred for their capability to quantify the degree of human visual fatigue without being affected by individual variation. However, little research has been conducted on the integration of objective indicators, or the sensibility of each objective indicator in reflecting subjective fatigue. The paper proposes a simply effective method to evaluate visual fatigue more objectively. The stereoscopic viewing process is divided into series of sessions, after each of which viewers rate their visual fatigue with subjective scores (SS) according to a five-grading scale, followed by tests of the punctum maximum accommodation (PMA) and visual reaction time (VRT). Throughout the entire viewing process, their eye movements are recorded by an infrared camera. The pupil size (PS) and percentage of eyelid closure over the pupil over time (PERCLOS) are extracted from the videos processed by the algorithm. Based on the method, an experiment with 14 subjects was conducted to assess visual fatigue induced by 3D images on polarized 3D display. The experiment consisted of 10 sessions (5min per session), each containing the same 75 images displayed randomly. The results show that PMA, VRT and PERCLOS are the most efficient indicators of subjective visual fatigue and finally a predictive model is derived from the stepwise multiple regressions.

  1. Stereoscopic 3D video games and their effects on engagement

    NASA Astrophysics Data System (ADS)

    Hogue, Andrew; Kapralos, Bill; Zerebecki, Chris; Tawadrous, Mina; Stanfield, Brodie; Hogue, Urszula

    2012-03-01

    With television manufacturers developing low-cost stereoscopic 3D displays, a large number of consumers will undoubtedly have access to 3D-capable televisions at home. The availability of 3D technology places the onus on content creators to develop interesting and engaging content. While the technology of stereoscopic displays and content generation are well understood, there are many questions yet to be answered surrounding its effects on the viewer. Effects of stereoscopic display on passive viewers for film are known, however video games are fundamentally different since the viewer/player is actively (rather than passively) engaged in the content. Questions of how stereoscopic viewing affects interaction mechanics have previously been studied in the context of player performance but very few have attempted to quantify the player experience to determine whether stereoscopic 3D has a positive or negative influence on their overall engagement. In this paper we present a preliminary study of the effects stereoscopic 3D have on player engagement in video games. Participants played a video game in two conditions, traditional 2D and stereoscopic 3D and their engagement was quantified using a previously validated self-reporting tool. The results suggest that S3D has a positive effect on immersion, presence, flow, and absorption.

  2. The importance of accurate convergence in addressing stereoscopic visual fatigue

    NASA Astrophysics Data System (ADS)

    Mayhew, Christopher A.

    2015-03-01

    Visual fatigue (asthenopia) continues to be a problem in extended viewing of stereoscopic imagery. Poorly converged imagery may contribute to this problem. In 2013, the Author reported that in a study sample a surprisingly high number of 3D feature films released as stereoscopic Blu-rays contained obvious convergence errors.1 The placement of stereoscopic image convergence can be an "artistic" call, but upon close examination, the sampled films seemed to have simply missed their intended convergence location. This failure maybe because some stereoscopic editing tools do not have the necessary fidelity to enable a 3D editor to obtain a high degree of image alignment or set an exact point of convergence. Compounding this matter further is the fact that a large number of stereoscopic editors may not believe that pixel accurate alignment and convergence is necessary. The Author asserts that setting a pixel accurate point of convergence on an object at the start of any given stereoscopic scene will improve the viewer's ability to fuse the left and right images quickly. The premise is that stereoscopic performance (acuity) increases when an accurately converged object is available in the image for the viewer to fuse immediately. Furthermore, this increased viewer stereoscopic performance should reduce the amount of visual fatigue associated with longer-term viewing because less mental effort will be required to perceive the imagery. To test this concept, we developed special stereoscopic imagery to measure viewer visual performance with and without specific objects for convergence. The Company Team conducted a series of visual tests with 24 participants between 25 and 60 years of age. This paper reports the results of these tests.

  3. Evaluating methods for controlling depth perception in stereoscopic cinematography

    NASA Astrophysics Data System (ADS)

    Sun, Geng; Holliman, Nick

    2009-02-01

    Existing stereoscopic imaging algorithms can create static stereoscopic images with perceived depth control function to ensure a compelling 3D viewing experience without visual discomfort. However, current algorithms do not normally support standard Cinematic Storytelling techniques. These techniques, such as object movement, camera motion, and zooming, can result in dynamic scene depth change within and between a series of frames (shots) in stereoscopic cinematography. In this study, we empirically evaluate the following three types of stereoscopic imaging approaches that aim to address this problem. (1) Real-Eye Configuration: set camera separation equal to the nominal human eye interpupillary distance. The perceived depth on the display is identical to the scene depth without any distortion. (2) Mapping Algorithm: map the scene depth to a predefined range on the display to avoid excessive perceived depth. A new method that dynamically adjusts the depth mapping from scene space to display space is presented in addition to an existing fixed depth mapping method. (3) Depth of Field Simulation: apply Depth of Field (DOF) blur effect to stereoscopic images. Only objects that are inside the DOF are viewed in full sharpness. Objects that are far away from the focus plane are blurred. We performed a human-based trial using the ITU-R BT.500-11 Recommendation to compare the depth quality of stereoscopic video sequences generated by the above-mentioned imaging methods. Our results indicate that viewers' practical 3D viewing volumes are different for individual stereoscopic displays and viewers can cope with much larger perceived depth range in viewing stereoscopic cinematography in comparison to static stereoscopic images. Our new dynamic depth mapping method does have an advantage over the fixed depth mapping method in controlling stereo depth perception. The DOF blur effect does not provide the expected improvement for perceived depth quality control in 3D cinematography

  4. Automatic stereoscopic system for person recognition

    NASA Astrophysics Data System (ADS)

    Murynin, Alexander B.; Matveev, Ivan A.; Kuznetsov, Victor D.

    1999-06-01

    A biometric access control system based on identification of human face is presented. The system developed performs remote measurements of the necessary face features. Two different scenarios of the system behavior are implemented. The first one assumes the verification of personal data entered by visitor from console using keyboard or card reader. The system functions as an automatic checkpoint, that strictly controls access of different visitors. The other scenario makes it possible to identify visitors without any person identifier or pass. Only person biometrics are used to identify the visitor. The recognition system automatically finds necessary identification information preliminary stored in the database. Two laboratory models of recognition system were developed. The models are designed to use different information types and sources. In addition to stereoscopic images inputted to computer from cameras the models can use voice data and some person physical characteristics such as person's height, measured by imaging system.

  5. Improvements in the Visualization of Stereoscopic 3D Imagery

    NASA Astrophysics Data System (ADS)

    Gurrieri, Luis E.

    2015-09-01

    A pleasant visualization of stereoscopic imagery must take into account factors that may produce eye strain and fatigue. Fortunately, our binocular vision system has embedded mechanisms to perceive depth for extended periods of time without producing eye fatigue; however, stereoscopic imagery may still induce visual discomfort in certain displaying scenarios. An important source of eye fatigue originates in the conflict between vergence eye movement and focusing mechanisms. Today's eye-tracking technology makes possible to know the viewers' gaze direction; hence, 3D imagery can be dynamically corrected based on this information. In this paper, I introduce a method to improve the visualization of stereoscopic imagery on planar displays based on emulating vergence and accommodation mechanisms of binocular human vision. Unlike other methods to improve the visual comfort that introduce depth distortions, in the stereoscopic visual media, this technique aims to produce a gentler and more natural binocular viewing experience without distorting the original depth of the scene.

  6. How are crosstalk and ghosting defined in the stereoscopic literature?

    NASA Astrophysics Data System (ADS)

    Woods, Andrew J.

    2011-03-01

    Crosstalk is a critical factor determining the image quality of stereoscopic displays. Also known as ghosting or leakage, high levels of crosstalk can make stereoscopic images hard to fuse and lack fidelity; hence it is important to achieve low levels of crosstalk in the development of high-quality stereoscopic displays. In the wider academic literature, the terms crosstalk, ghosting and leakage are often used interchangeably and unfortunately very few publications actually provide a descriptive or mathematical definition of these terms. Additionally the definitions that are available are sometimes contradictory. This paper reviews how the terms crosstalk, ghosting and associated terms (system crosstalk, viewer crosstalk, gray-to-gray crosstalk, leakage, extinction and extinction ratio, and 3D contrast) are defined and used in the stereoscopic literature. Both descriptive definitions and mathematical definitions are considered.

  7. Recent developments in stereoscopic and holographic 3D display technologies

    NASA Astrophysics Data System (ADS)

    Sarma, Kalluri

    2014-06-01

    Currently, there is increasing interest in the development of high performance 3D display technologies to support a variety of applications including medical imaging, scientific visualization, gaming, education, entertainment, air traffic control and remote operations in 3D environments. In this paper we will review the attributes of the various 3D display technologies including stereoscopic and holographic 3D, human factors issues of stereoscopic 3D, the challenges in realizing Holographic 3D displays and the recent progress in these technologies.

  8. Interactive floating windows: a new technique for stereoscopic video games

    NASA Astrophysics Data System (ADS)

    Zerebecki, Chris; Stanfield, Brodie; Tawadrous, Mina; Buckstein, Daniel; Hogue, Andrew; Kapralos, Bill

    2012-03-01

    The film industry has a long history of creating compelling experiences in stereoscopic 3D. Recently, the video game as an artistic medium has matured into an effective way to tell engaging and immersive stories. Given the current push to bring stereoscopic 3D technology into the consumer market there is considerable interest to develop stereoscopic 3D video games. Game developers have largely ignored the need to design their games specifically for stereoscopic 3D and have thus relied on automatic conversion and driver technology. Game developers need to evaluate solutions used in other media, such as film, to correct perceptual problems such as window violations, and modify or create new solutions to work within an interactive framework. In this paper we extend the dynamic floating window technique into the interactive domain enabling the player to position a virtual window in space. Interactively changing the position, size, and the 3D rotation of the virtual window, objects can be made to 'break the mask' dramatically enhancing the stereoscopic effect. By demonstrating that solutions from the film industry can be extended into the interactive space, it is our hope that this initiates further discussion in the game development community to strengthen their story-telling mechanisms in stereoscopic 3D games.

  9. Examination of 3D visual attention in stereoscopic video content

    NASA Astrophysics Data System (ADS)

    Huynh-Thu, Quan; Schiatti, Luca

    2011-03-01

    Recent advances in video technology and digital cinema have made it possible to produce entertaining 3D stereoscopic content that can be viewed for an extended duration without necessarily causing extreme fatigue, visual strain and discomfort. Viewers focus naturally their attention on specific areas of interest in their visual field. Visual attention is an important aspect of perception and its understanding is therefore an important aspect for the creation of 3D stereoscopic content. Most of the studies on visual attention have focused on the case of still images or 2D video. Only a very few studies have investigated eye movement patterns in 3D stereoscopic moving sequences, and how these may differ from viewing 2D video content. In this paper, we present and discuss the results of a subjective experiment that we conducted using an eye-tracking apparatus to record observers' gaze patterns. Participants were asked to watch the same set of video clips in a free-viewing task. Each clip was shown in a 3D stereoscopic version and 2D version. Our results indicate that the extent of areas of interests is not necessarily wider in 3D. We found a very strong content dependency in the difference of density and locations of fixations between 2D and 3D stereoscopic content. However, we found that saccades were overall faster and that fixation durations were overall lower when observers viewed the 3D stereoscopic version.

  10. Stereoscopic Integrated Imaging Goggles for Multimodal Intraoperative Image Guidance

    PubMed Central

    Mela, Christopher A.; Patterson, Carrie; Thompson, William K.; Papay, Francis; Liu, Yang

    2015-01-01

    We have developed novel stereoscopic wearable multimodal intraoperative imaging and display systems entitled Integrated Imaging Goggles for guiding surgeries. The prototype systems offer real time stereoscopic fluorescence imaging and color reflectance imaging capacity, along with in vivo handheld microscopy and ultrasound imaging. With the Integrated Imaging Goggle, both wide-field fluorescence imaging and in vivo microscopy are provided. The real time ultrasound images can also be presented in the goggle display. Furthermore, real time goggle-to-goggle stereoscopic video sharing is demonstrated, which can greatly facilitate telemedicine. In this paper, the prototype systems are described, characterized and tested in surgeries in biological tissues ex vivo. We have found that the system can detect fluorescent targets with as low as 60 nM indocyanine green and can resolve structures down to 0.25 mm with large FOV stereoscopic imaging. The system has successfully guided simulated cancer surgeries in chicken. The Integrated Imaging Goggle is novel in 4 aspects: it is (a) the first wearable stereoscopic wide-field intraoperative fluorescence imaging and display system, (b) the first wearable system offering both large FOV and microscopic imaging simultaneously, (c) the first wearable system that offers both ultrasound imaging and fluorescence imaging capacities, and (d) the first demonstration of goggle-to-goggle communication to share stereoscopic views for medical guidance. PMID:26529249

  11. Instant color print photography in dermatology.

    PubMed

    Olmstead, C B

    1982-06-01

    The use of instant color print photography in dermatology is explored and evaluated in this article. Recent advances in the technology of instant photography have made it possible for the creation of fast, accurate, clinical photographs by people with little experience or training. The Polaroid SX-70 Sonar camera with the CU-70 close-up kit is evaluated and compared to the Kodak instant close-up camera kit as marketed by the Lester A. Dine Company. The advantages and disadvantages of the two camera systems are presented. Techniques such as lighting, proper distance, and exposure are discussed with mention of the method of converting prints into slides. The many and varied applications of this modality are reviewed. Rapid, sharp, reproducible clinical photographs can now be obtained instantaneously by the busy clinician.

  12. What is stereoscopic vision good for?

    NASA Astrophysics Data System (ADS)

    Read, Jenny C. A.

    2015-03-01

    Stereo vision is a resource-intensive process. Nevertheless, it has evolved in many animals including mammals, birds, amphibians and insects. It must therefore convey significant fitness benefits. It is often assumed that the main benefit is improved accuracy of depth judgments, but camouflage breaking may be as important, particularly in predatory animals. In humans, for the last 150 years, stereo vision has been turned to a new use: helping us reproduce visual reality for artistic purposes. By recreating the different views of a scene seen by the two eyes, stereo achieves unprecedented levels of realism. However, it also has some unexpected effects on viewer experience. The disruption of established mechanisms for interpreting pictures may be one reason why some viewers find stereoscopic content disturbing. Stereo vision also has uses in ophthalmology. Clinical stereoacuity tests are used in the management of conditions such as strabismus and amblyopia as well as vision screening. Stereoacuity can reveal the effectiveness of therapy and even predict long-term outcomes post surgery. Yet current clinical stereo tests fall far short of the accuracy and precision achievable in the lab. At Newcastle University, we are exploiting the recent availability of autostereo 3D tablet computers to design a clinical stereotest app in the form of a game suitable for young children. Our goal is to enable quick, accurate and precise stereoacuity measures which will enable clinicians to obtain better outcomes for children with visual disorders.

  13. Binocular coordination: reading stereoscopic sentences in depth.

    PubMed

    Schotter, Elizabeth R; Blythe, Hazel I; Kirkby, Julie A; Rayner, Keith; Holliman, Nicolas S; Liversedge, Simon P

    2012-01-01

    The present study employs a stereoscopic manipulation to present sentences in three dimensions to subjects as they read for comprehension. Subjects read sentences with (a) no depth cues, (b) a monocular depth cue that implied the sentence loomed out of the screen (i.e., increasing retinal size), (c) congruent monocular and binocular (retinal disparity) depth cues (i.e., both implied the sentence loomed out of the screen) and (d) incongruent monocular and binocular depth cues (i.e., the monocular cue implied the sentence loomed out of the screen and the binocular cue implied it receded behind the screen). Reading efficiency was mostly unaffected, suggesting that reading in three dimensions is similar to reading in two dimensions. Importantly, fixation disparity was driven by retinal disparity; fixations were significantly more crossed as readers progressed through the sentence in the congruent condition and significantly more uncrossed in the incongruent condition. We conclude that disparity depth cues are used on-line to drive binocular coordination during reading.

  14. Interlopers 3D: experiences designing a stereoscopic game

    NASA Astrophysics Data System (ADS)

    Weaver, James; Holliman, Nicolas S.

    2014-03-01

    Background In recent years 3D-enabled televisions, VR headsets and computer displays have become more readily available in the home. This presents an opportunity for game designers to explore new stereoscopic game mechanics and techniques that have previously been unavailable in monocular gaming. Aims To investigate the visual cues that are present in binocular and monocular vision, identifying which are relevant when gaming using a stereoscopic display. To implement a game whose mechanics are so reliant on binocular cues that the game becomes impossible or at least very difficult to play in non-stereoscopic mode. Method A stereoscopic 3D game was developed whose objective was to shoot down advancing enemies (the Interlopers) before they reached their destination. Scoring highly required players to make accurate depth judgments and target the closest enemies first. A group of twenty participants played both a basic and advanced version of the game in both monoscopic 2D and stereoscopic 3D. Results The results show that in both the basic and advanced game participants achieved higher scores when playing in stereoscopic 3D. The advanced game showed that by disrupting the depth from motion cue the game became more difficult in monoscopic 2D. Results also show a certain amount of learning taking place over the course of the experiment, meaning that players were able to score higher and finish the game faster over the course of the experiment. Conclusions Although the game was not impossible to play in monoscopic 2D, participants results show that it put them at a significant disadvantage when compared to playing in stereoscopic 3D.

  15. 21 CFR 137.170 - Instantized flours.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Instantized flours. 137.170 Section 137.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized...

  16. Instant Messaging, Literacies, and Social Identities

    ERIC Educational Resources Information Center

    Lewis, Cynthia; Fabos, Bettina

    2005-01-01

    This study examined the functions of Instant Messaging (IM) among seven youths who regularly used this digital technology in their daily lives. Grounded in theories of literacy as a social and semiotic practice, this research asked what functions IM served in participants' lives and how their social identities shaped and were shaped by this form…

  17. Using Instant Messaging for Online Reference Service

    ERIC Educational Resources Information Center

    Forster, Shirley

    2006-01-01

    Many libraries are using co-browsing chat products to provide reference services to their patrons, whilst their patrons are online and using the internet. The concept of such an online service is highly desirable, but many libraries are concerned that they will never be able to afford such a system. This may have changed: Instant Messaging (IM)…

  18. Instant Messaging Reference: How Does It Compare?

    ERIC Educational Resources Information Center

    Desai, Christina M.

    2003-01-01

    Compares a digital reference service that uses instant messaging with traditional, face-to-face reference based on experiences at the Southern Illinois University library. Addresses differences in reference questions asked, changes in the reference transaction, student expectations, bibliographic instruction, and librarian attitudes and procedures…

  19. 21 CFR 137.170 - Instantized flours.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Instantized flours. 137.170 Section 137.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR..., and quick-mixing flours, are the foods each of which conforms to the definition and standard...

  20. 21 CFR 137.170 - Instantized flours.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Instantized flours. 137.170 Section 137.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR..., and quick-mixing flours, are the foods each of which conforms to the definition and standard...

  1. 21 CFR 137.170 - Instantized flours.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Instantized flours. 137.170 Section 137.170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR..., and quick-mixing flours, are the foods each of which conforms to the definition and standard...

  2. Interactive 2D to 3D stereoscopic image synthesis

    NASA Astrophysics Data System (ADS)

    Feldman, Mark H.; Lipton, Lenny

    2005-03-01

    Advances in stereoscopic display technologies, graphic card devices, and digital imaging algorithms have opened up new possibilities in synthesizing stereoscopic images. The power of today"s DirectX/OpenGL optimized graphics cards together with adapting new and creative imaging tools found in software products such as Adobe Photoshop, provide a powerful environment for converting planar drawings and photographs into stereoscopic images. The basis for such a creative process is the focus of this paper. This article presents a novel technique, which uses advanced imaging features and custom Windows-based software that utilizes the Direct X 9 API to provide the user with an interactive stereo image synthesizer. By creating an accurate and interactive world scene with moveable and flexible depth map altered textured surfaces, perspective stereoscopic cameras with both visible frustums and zero parallax planes, a user can precisely model a virtual three-dimensional representation of a real-world scene. Current versions of Adobe Photoshop provide a creative user with a rich assortment of tools needed to highlight elements of a 2D image, simulate hidden areas, and creatively shape them for a 3D scene representation. The technique described has been implemented as a Photoshop plug-in and thus allows for a seamless transition of these 2D image elements into 3D surfaces, which are subsequently rendered to create stereoscopic views.

  3. Classifying EEG Signals during Stereoscopic Visualization to Estimate Visual Comfort

    PubMed Central

    Frey, Jérémy; Appriou, Aurélien; Lotte, Fabien; Hachet, Martin

    2016-01-01

    With stereoscopic displays a sensation of depth that is too strong could impede visual comfort and may result in fatigue or pain. We used Electroencephalography (EEG) to develop a novel brain-computer interface that monitors users' states in order to reduce visual strain. We present the first system that discriminates comfortable conditions from uncomfortable ones during stereoscopic vision using EEG. In particular, we show that either changes in event-related potentials' (ERPs) amplitudes or changes in EEG oscillations power following stereoscopic objects presentation can be used to estimate visual comfort. Our system reacts within 1 s to depth variations, achieving 63% accuracy on average (up to 76%) and 74% on average when 7 consecutive variations are measured (up to 93%). Performances are stable (≈62.5%) when a simplified signal processing is used to simulate online analyses or when the number of EEG channels is lessened. This study could lead to adaptive systems that automatically suit stereoscopic displays to users and viewing conditions. For example, it could be possible to match the stereoscopic effect with users' state by modifying the overlap of left and right images according to the classifier output. PMID:26819580

  4. Effects of stereoscopic presentation on visually induced motion sickness

    NASA Astrophysics Data System (ADS)

    Ujike, Hiroyasu; Watanabe, Hiroshi

    2011-03-01

    The present study investigates whether VIMS, which can be induced in 2D images, is affected by stereoscopic presentation. To do this, we conducted an experiment to measure the effects psychologically and physiologically. Visual stimulus was computer graphics that simulates traveling along streets with additional pitch and roll motion for 10 minutes. The stimulus were presented as either stereoscopic, "3D", images or "2D" images. Before/after and during each trial, psychological and physiological measurements for biomedical effects were conducted. As results, psychological measurements indicate effects of stereoscopic presentations on VIMS. First, subjective score of comfort level measured every one minute significantly decreased to uncomfortable level in the 3D than in the 2D condition. Second, subscore of "Nausea" of Simulator Sickness Questionnaire significantly higher in the 3D than in the 2D condition, while the other subscores and the total score also showed the similar tendency. Moreover, physiological measurements also indicate effects of 3D presentations on VIMS. The LF/HF ratio, which is the index of sympathetic nerve activity, clearly increased more in the 3D than in the 2D condition. We conclude that stereoscopic presentation enhances biomedical effects of VIMS. We speculate that stereoscopic images can be efficient reference of spatial orientation.

  5. Classifying EEG Signals during Stereoscopic Visualization to Estimate Visual Comfort.

    PubMed

    Frey, Jérémy; Appriou, Aurélien; Lotte, Fabien; Hachet, Martin

    2016-01-01

    With stereoscopic displays a sensation of depth that is too strong could impede visual comfort and may result in fatigue or pain. We used Electroencephalography (EEG) to develop a novel brain-computer interface that monitors users' states in order to reduce visual strain. We present the first system that discriminates comfortable conditions from uncomfortable ones during stereoscopic vision using EEG. In particular, we show that either changes in event-related potentials' (ERPs) amplitudes or changes in EEG oscillations power following stereoscopic objects presentation can be used to estimate visual comfort. Our system reacts within 1 s to depth variations, achieving 63% accuracy on average (up to 76%) and 74% on average when 7 consecutive variations are measured (up to 93%). Performances are stable (≈62.5%) when a simplified signal processing is used to simulate online analyses or when the number of EEG channels is lessened. This study could lead to adaptive systems that automatically suit stereoscopic displays to users and viewing conditions. For example, it could be possible to match the stereoscopic effect with users' state by modifying the overlap of left and right images according to the classifier output. PMID:26819580

  6. The Stereoscopic Anisotropy Develops During Childhood

    PubMed Central

    Serrano-Pedraza, Ignacio; Herbert, William; Villa-Laso, Laura; Widdall, Michael; Vancleef, Kathleen; Read, Jenny C. A.

    2016-01-01

    Purpose Human vision has a puzzling stereoscopic anisotropy: horizontal depth corrugations are easier to detect than vertical depth corrugations. To date, little is known about the function or the underlying mechanism responsible for this anisotropy. Here, we aim to find out whether this anisotropy is independent of age. To answer this, we compare detection thresholds for horizontal and vertical depth corrugations as a function of age. Methods The depth corrugations were defined solely by the horizontal disparity of random dot patterns. The disparities depicted a horizontal or vertical sinusoidal depth corrugation of spatial frequency 0.1 cyc/deg. Detection thresholds were obtained using Bayesian adaptive staircases from a total of 159 subjects aged from 3 to 73 years. For each participant we computed the anisotropy index, defined as the log10-ratio of the detection threshold for vertical corrugations divided by that for horizontal. Results Anisotropy index was highly variable between individuals but was positive in 87% of the participants. There was a significant correlation between anisotropy index and log-age (r = 0.21, P = 0.008) mainly driven by a significant difference between children and adults. In 67 children aged 3 to 13 years, the mean anisotropy index was 0.34 ± 0.38 (mean ± SD, meaning that vertical thresholds were on average 2.2 times the horizontal ones), compared with 0.59 ± 0.55 in 84 adults aged 18 to 73 years (vertical 3.9 times horizontal). This was mainly driven by a decline in the sensitivity to vertical corrugations. Children had poorer stereoacuity than adults, but had similar sensitivity to adults for horizontal corrugations and were actually more sensitive than adults to vertical corrugations. Conclusions The fact that adults show stronger stereo anisotropy than children raises the possibility that visual experience plays a critical role in developing and strengthening the stereo anisotropy. PMID:26962692

  7. Contrast sensitivity function in stereoscopic viewing of Gabor patches on a medical polarized three-dimensional stereoscopic display

    NASA Astrophysics Data System (ADS)

    Rousson, Johanna; Haar, Jérémy; Santal, Sarah; Kumcu, Asli; Platiša, Ljiljana; Piepers, Bastian; Kimpe, Tom; Philips, Wilfried

    2016-03-01

    While three-dimensional (3-D) imaging systems are entering hospitals, no study to date has explored the luminance calibration needs of 3-D stereoscopic diagnostic displays and if they differ from two-dimensional (2-D) displays. Since medical display calibration incorporates the human contrast sensitivity function (CSF), we first assessed the 2-D CSF for benchmarking and then examined the impact of two image parameters on the 3-D stereoscopic CSF: (1) five depth plane (DP) positions (between DP: -171 and DP: 2853 mm), and (2) three 3-D inclinations (0 deg, 45 deg, and 60 deg around the horizontal axis of a DP). Stimuli were stereoscopic images of a vertically oriented 2-D Gabor patch at one of seven frequencies ranging from 0.4 to 10 cycles/deg. CSFs were measured for seven to nine human observers with a staircase procedure. The results indicate that the 2-D CSF model remains valid for a 3-D stereoscopic display regardless of the amount of disparity between the stereo images. We also found that the 3-D CSF at DP≠0 does not differ from the 3-D CSF at DP=0 for DPs and disparities which allow effortless binocular fusion. Therefore, the existing 2-D medical luminance calibration algorithm remains an appropriate tool for calibrating polarized stereoscopic medical displays.

  8. What do people look at when they watch stereoscopic movies?

    NASA Astrophysics Data System (ADS)

    Häkkinen, Jukka; Kawai, Takashi; Takatalo, Jari; Mitsuya, Reiko; Nyman, Göte

    2010-02-01

    We measured the eye movements of participants who watched a 6-minute movie in stereoscopic and non-stereoscopic form. We analyzed four shots of the movie. The results indicate that in a 2D movie viewers tended to look at the actors, as most of the eye movements were clustered there. The significance of the actors started at the beginning of a shot, as the eyes of the viewer focused almost immediately to them. In S3D movie the eye movement patterns were more widely distributed to other targets. For example, complex stereoscopic structures and objects nearer than the actor captured the interest and eye movements of the participants. Also, the tendency to first look at the actors was diminished in the S3D shots. The results suggests that in a S3D movie there are more eye movements which are directed to wider array of objects than in a 2D movie.

  9. 7 CFR 58.249 - Instant nonfat dry milk.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Instant nonfat dry milk. 58.249 Section 58.249... Products Bearing Usda Official Identification § 58.249 Instant nonfat dry milk. (a) Only instant nonfat dry milk manufactured and packaged in accordance with the requirements of this part and with the...

  10. 7 CFR 58.249 - Instant nonfat dry milk.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Instant nonfat dry milk. 58.249 Section 58.249... Products Bearing Usda Official Identification § 58.249 Instant nonfat dry milk. (a) Only instant nonfat dry milk manufactured and packaged in accordance with the requirements of this part and with the...

  11. 7 CFR 58.249 - Instant nonfat dry milk.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Instant nonfat dry milk. 58.249 Section 58.249... Products Bearing Usda Official Identification § 58.249 Instant nonfat dry milk. (a) Only instant nonfat dry milk manufactured and packaged in accordance with the requirements of this part and with the...

  12. 7 CFR 58.249 - Instant nonfat dry milk.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Instant nonfat dry milk. 58.249 Section 58.249... Products Bearing Usda Official Identification § 58.249 Instant nonfat dry milk. (a) Only instant nonfat dry milk manufactured and packaged in accordance with the requirements of this part and with the...

  13. 7 CFR 58.249 - Instant nonfat dry milk.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Instant nonfat dry milk. 58.249 Section 58.249... Products Bearing Usda Official Identification § 58.249 Instant nonfat dry milk. (a) Only instant nonfat dry milk manufactured and packaged in accordance with the requirements of this part and with the...

  14. Three-dimensional (3D) stereoscopic X windows

    NASA Astrophysics Data System (ADS)

    Safier, Scott A.; Siegel, Mel

    1995-03-01

    All known technologies for displaying 3D-stereoscopic images are more or less incompatible with the X Window System. Applications that seek to be portable must support the 3D-display paradigms of multiple hardware implementations of 3D-stereoscopy. We have succeeded in modifying the functionality of X to construct generic tools for displaying 3D-stereoscopic imagery. Our approach allows for experimentation with visualization techniques and techniques for interacting with these synthetic worlds. Our methodology inherits the extensibility and portability of X. We have demonstrated its applicability in two display hardware paradigms that are specifically discussed.

  15. Preparation of partially decaffeinated instant green tea.

    PubMed

    Ye, Jian-Hui; Liang, Yue-Rong; Jin, Jing; Liang, Hue-Ling; Du, Ying-Ying; Lu, Jian-Liang; Ye, Qian; Lin, Chen

    2007-05-01

    The caffeine level of instant tea extracted from decaffeinated leaf tea with 4.0 mg g-1 caffeine is commonly above 10.0 mg g-1, the maximum limit of caffeine for decaffeinated instant tea. Further removal of caffeine by active carbon (AC) from the green tea extract was investigated. It showed that the removal of caffeine from the tea extract solutions depended on the treatment time and tea extract concentration while the ethanol concentration and pH had little effect on the removal of caffeine. According to the removal of caffeine and the ratio of total catechins to caffeine in the tested samples, the optimum decaffeination conditions were determined to be as follows: tea extract concentration 15-30 g L-1 for common tea extract but higher for partially decaffeinated tea leaf extract; ratio of tea solution to AC, 100 mL:4 g; treatment time, 4 h; and natural tea extract pH. Instant tea powder extracted from partially decaffeinated leaf tea with a caffeine level of 4.03 mg g-1 and further decaffeinated by AC had a caffeine level of 7.81 mg g-1, which was 31% lower than that without AC treatment.

  16. Biorefinery of instant noodle waste to biofuels.

    PubMed

    Yang, Xiaoguang; Lee, Sang Jun; Yoo, Hah Young; Choi, Han Suk; Park, Chulhwan; Kim, Seung Wook

    2014-05-01

    Instant noodle waste, one of the main residues of the modern food industry, was employed as feedstock to convert to valuable biofuels. After isolation of used oil from the instant noodle waste surface, the starch residue was converted to bioethanol by Saccharomyces cerevisiae K35 with simultaneous saccharification and fermentation (SSF). The maximum ethanol concentration and productivity was 61.1g/l and 1.7 g/lh, respectively. After the optimization of fermentation, ethanol conversion rate of 96.8% was achieved within 36 h. The extracted oil was utilized as feedstock for high quality biodiesel conversion with typical chemical catalysts (KOH and H2SO4). The optimum conversion conditions for these two catalysts were estimated; and the highest biodiesel conversion rates were achieved 98.5% and 97.8%, within 2 and 3h, respectively. The high conversion rates of both bioethanol and biodiesel demonstrate that novel substrate instant noodle waste can be an attractive biorefinery feedstock in the biofuels industry.

  17. Preparation of partially decaffeinated instant green tea.

    PubMed

    Ye, Jian-Hui; Liang, Yue-Rong; Jin, Jing; Liang, Hue-Ling; Du, Ying-Ying; Lu, Jian-Liang; Ye, Qian; Lin, Chen

    2007-05-01

    The caffeine level of instant tea extracted from decaffeinated leaf tea with 4.0 mg g-1 caffeine is commonly above 10.0 mg g-1, the maximum limit of caffeine for decaffeinated instant tea. Further removal of caffeine by active carbon (AC) from the green tea extract was investigated. It showed that the removal of caffeine from the tea extract solutions depended on the treatment time and tea extract concentration while the ethanol concentration and pH had little effect on the removal of caffeine. According to the removal of caffeine and the ratio of total catechins to caffeine in the tested samples, the optimum decaffeination conditions were determined to be as follows: tea extract concentration 15-30 g L-1 for common tea extract but higher for partially decaffeinated tea leaf extract; ratio of tea solution to AC, 100 mL:4 g; treatment time, 4 h; and natural tea extract pH. Instant tea powder extracted from partially decaffeinated leaf tea with a caffeine level of 4.03 mg g-1 and further decaffeinated by AC had a caffeine level of 7.81 mg g-1, which was 31% lower than that without AC treatment. PMID:17407319

  18. 3D Stereoscopic Visualization of Fenestrated Stent Grafts

    SciTech Connect

    Sun Zhonghua; Squelch, Andrew; Bartlett, Andrew; Cunningham, Kylie; Lawrence-Brown, Michael

    2009-09-15

    The purpose of this study was to present a technique of stereoscopic visualization in the evaluation of patients with abdominal aortic aneurysm treated with fenestrated stent grafts compared with conventional 2D visualizations. Two patients with abdominal aortic aneurysm undergoing fenestrated stent grafting were selected for inclusion in the study. Conventional 2D views including axial, multiplanar reformation, maximum-intensity projection, and volume rendering and 3D stereoscopic visualizations were assessed by two experienced reviewers independently with regard to the treatment outcomes of fenestrated repair. Interobserver agreement was assessed with Kendall's W statistic. Multiplanar reformation and maximum-intensity projection visualizations were scored the highest in the evaluation of parameters related to the fenestrated stent grafting, while 3D stereoscopic visualization was scored as valuable in the evaluation of appearance (any distortions) of the fenestrated stent. Volume rendering was found to play a limited role in the follow-up of fenestrated stent grafting. 3D stereoscopic visualization adds additional information that assists endovascular specialists to identify any distortions of the fenestrated stents when compared with 2D visualizations.

  19. The rendering context for stereoscopic 3D web

    NASA Astrophysics Data System (ADS)

    Chen, Qinshui; Wang, Wenmin; Wang, Ronggang

    2014-03-01

    3D technologies on the Web has been studied for many years, but they are basically monoscopic 3D. With the stereoscopic technology gradually maturing, we are researching to integrate the binocular 3D technology into the Web, creating a stereoscopic 3D browser that will provide users with a brand new experience of human-computer interaction. In this paper, we propose a novel approach to apply stereoscopy technologies to the CSS3 3D Transforms. Under our model, each element can create or participate in a stereoscopic 3D rendering context, in which 3D Transforms such as scaling, translation and rotation, can be applied and be perceived in a truly 3D space. We first discuss the underlying principles of stereoscopy. After that we discuss how these principles can be applied to the Web. A stereoscopic 3D browser with backward compatibility is also created for demonstration purposes. We take advantage of the open-source WebKit project, integrating the 3D display ability into the rendering engine of the web browser. For each 3D web page, our 3D browser will create two slightly different images, each representing the left-eye view and right-eye view, both to be combined on the 3D display to generate the illusion of depth. And as the result turns out, elements can be manipulated in a truly 3D space.

  20. Screen of cylindrical lenses produces stereoscopic television pictures

    NASA Technical Reports Server (NTRS)

    Nork, C. L.

    1966-01-01

    Stereoscopic television pictures are produced by placing a colorless, transparent screen of adjacent parallel cylindrical lenses before a raster from two synchronized TV cameras. Alternate frames from alternate cameras are displayed. The viewers sensory perception fuses the two images into one three-dimensional picture.

  1. Optimizing 3D image quality and performance for stereoscopic gaming

    NASA Astrophysics Data System (ADS)

    Flack, Julien; Sanderson, Hugh; Pegg, Steven; Kwok, Simon; Paterson, Daniel

    2009-02-01

    The successful introduction of stereoscopic TV systems, such as Samsung's 3D Ready Plasma, requires high quality 3D content to be commercially available to the consumer. Console and PC games provide the most readily accessible source of high quality 3D content. This paper describes innovative developments in a generic, PC-based game driver architecture that addresses the two key issues affecting 3D gaming: quality and speed. At the heart of the quality issue are the same considerations that studios face producing stereoscopic renders from CG movies: how best to perform the mapping from a geometric CG environment into the stereoscopic display volume. The major difference being that for game drivers this mapping cannot be choreographed by hand but must be automatically calculated in real-time without significant impact on performance. Performance is a critical issue when dealing with gaming. Stereoscopic gaming has traditionally meant rendering the scene twice with the associated performance overhead. An alternative approach is to render the scene from one virtual camera position and use information from the z-buffer to generate a stereo pair using Depth-Image-Based Rendering (DIBR). We analyze this trade-off in more detail and provide some results relating to both 3D image quality and render performance.

  2. Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues

    PubMed Central

    Bell, Jason; Dickinson, Edwin; Badcock, David R.; Kingdom, Frederick A. A.

    2013-01-01

    The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects. PMID:24335717

  3. Balance and coordination after viewing stereoscopic 3D television

    PubMed Central

    Read, Jenny C. A.; Simonotto, Jennifer; Bohr, Iwo; Godfrey, Alan; Galna, Brook; Rochester, Lynn; Smulders, Tom V.

    2015-01-01

    Manufacturers and the media have raised the possibility that viewing stereoscopic 3D television (S3D TV) may cause temporary disruption to balance and visuomotor coordination. We looked for evidence of such effects in a laboratory-based study. Four hundred and thirty-three people aged 4–82 years old carried out tests of balance and coordination before and after viewing an 80 min movie in either conventional 2D or stereoscopic 3D, while wearing two triaxial accelerometers. Accelerometry produced little evidence of any change in body motion associated with S3D TV. We found no evidence that viewing the movie in S3D causes a detectable impairment in balance or in visuomotor coordination. PMID:26587261

  4. Current status of stereoscopic 3D LCD TV technologies

    NASA Astrophysics Data System (ADS)

    Choi, Hee-Jin

    2011-06-01

    The year 2010 may be recorded as a first year of successful commercial 3D products. Among them, the 3D LCD TVs are expected to be the major one regarding the sales volume. In this paper, the principle of current stereoscopic 3D LCD TV techniques and the required flat panel display (FPD) technologies for the realization of them are reviewed. [Figure not available: see fulltext.

  5. Stereoscopic Height Estimation from Multiple Aspect Synthetic Aperture Radar Images

    SciTech Connect

    DELAURENTIS,JOHN M.; DOERRY,ARMIN W.

    2001-08-01

    A Synthetic Aperture Radar (SAR) image is a two-dimensional projection of the radar reflectivity from a 3-dimensional object or scene. Stereoscopic SAR employs two SAR images from distinct flight paths that can be processed together to extract information of the third collapsed dimension (typically height) with some degree of accuracy. However, more than two SAR images of the same scene can similarly be processed to further improve height accuracy, and hence 3-dimensional position accuracy. This report shows how.

  6. Generation of circularly polarized stereoscopic transparencies and prints

    NASA Astrophysics Data System (ADS)

    Walworth, Vivian K.; Slafer, W. Dennis

    2010-02-01

    We describe a new iteration of the StereoJet process, which has been simplified by changes in materials and improved by the conversion from linear to circular polarization. A prototype StereoJet process for producing full color stereoscopic images, described several years ago by Scarpetti et al., was developed at the Rowland Institute for Science, now part of Harvard University. The system was based on the inkjet application of inks comprising dichroic dyes to Polaroid Vectograph sheet, a concept explored earlier by Walworth and Chiulli at the Polaroid Research Laboratories. Vectograph sheet comprised two oppositely oriented layers of stretched polyvinyl alcohol (PVA) laminated to opposite surfaces of a cellulose triacetate support sheet. The two PVA layers were oriented at +45 and -45 degrees, respectively, with respect to the running edge of the support sheet. A left-eye and right-eye stereoscopic image pair were printed sequentially on the respective surfaces, and the resulting stereoscopic image viewed with conventional linearly polarized glasses having +45 and -45 degree orientation. StereoJet, Inc. has developed new, simplified technology based on the use of PVA substrate of the type used in sheet polarizer manufacture with orientation parallel to the running edge of the support. Left- and right-eye images are printed at 0 and 90 degrees, then laminated in register. Addition of a thin layer of 1/4-wave retarder to the front surface converts the image pair's respective orientations to right- and left-circular polarization. The full color stereoscopic images are viewed with circularly polarized glasses.

  7. Visually preserving stereoscopic image retargeting using depth carving

    NASA Astrophysics Data System (ADS)

    Lu, Dawei; Ma, Huadong; Liu, Liang

    2016-03-01

    This paper presents a method for retargeting a pair of stereoscopic images. Previous works have leveraged seam carving and image warping methods for two-dimensional image editing to address this issue. However, they did not consider the full advantages of the properties of stereoscopic images. Our approach offers substantial performance improvements over the state-of-the-art; the key insights driving the approach are that the input image pair can be decomposed into different depth layers according to the disparity and image segmentation, and the depth cues allow us to address the problem in a three-dimensional (3-D) space domain for best preserving objects. We propose depth carving that extends seam carving in a single image to resize the stereo image pair with disparity consistency. Our method minimizes the shape distortion and preserves object boundaries by creating new occlusions. As a result, the retargeted image pair preserves the stereoscopic quality and protects the original 3-D scene structure. Experimental results demonstrate that our method outperforms the previous methods.

  8. Light loss reduction of LCD polarized stereoscopic projection

    NASA Astrophysics Data System (ADS)

    Elkhov, Victor A.; Ovechkis, Yuri N.

    2003-05-01

    The overwhelming majority of LCD projectors that are used for polarized stereoscopic projection have linear polarized output with two colors in one direction and the third color in an orthogonal direction (e.g. green is horizontal and red and blue are vertical). During standard conversion of two projectors light to orthogonal or circular clockwise and counter-clockwise polarization more than fifty percent of light energy is lost. This paper considers a method of polarized stereoscopic projection that gives less light loss. For this purpose the light of each LCD projector is converted to circular polarization by using quarter wave retarder plates. Orientation of its optical axes are chosen so that green light from the first projector and red and blue light from the second projector are circularly polarized in the clockwise direction. The remaining colors are circular polarized in the counter-clockwise polarization. Simultaneously color transformation of stereo pairs pictures is realized. Green component of first picture is mixed with red and blue component of second picture and vice versa. This method enables the observation of good quality stereoscopic images using glasses with circular polarizers. In the case of glasses with linear polarization, half wave plates for conversion of LCD projectors light are used.

  9. Semi-autonomous wheelchair system using stereoscopic cameras.

    PubMed

    Nguyen, Jordan S; Nguyen, Thanh H; Nguyen, Hung T

    2009-01-01

    This paper is concerned with the design and development of a semi-autonomous wheelchair system using stereoscopic cameras to assist hands-free control technologies for severely disabled people. The stereoscopic cameras capture an image from both the left and right cameras, which are then processed with a Sum of Absolute Differences (SAD) correlation algorithm to establish correspondence between image features in the different views of the scene. This is used to produce a stereo disparity image containing information about the depth of objects away from the camera in the image. A geometric projection algorithm is then used to generate a 3-Dimensional (3D) point map, placing pixels of the disparity image in 3D space. This is then converted to a 2-Dimensional (2D) depth map allowing objects in the scene to be viewed and a safe travel path for the wheelchair to be planned and followed based on the user's commands. This assistive technology utilising stereoscopic cameras has the purpose of automated obstacle detection, path planning and following, and collision avoidance during navigation. Experimental results obtained in an indoor environment displayed the effectiveness of this assistive technology.

  10. A systematized WYSIWYG pipeline for digital stereoscopic 3D filmmaking

    NASA Astrophysics Data System (ADS)

    Mueller, Robert; Ward, Chris; Hušák, Michal

    2008-02-01

    Digital tools are transforming stereoscopic 3D content creation and delivery, creating an opportunity for the broad acceptance and success of stereoscopic 3D films. Beginning in late 2005, a series of mostly CGI features has successfully initiated the public to this new generation of highly-comfortable, artifact-free digital 3D. While the response has been decidedly favorable, a lack of high-quality live-action films could hinder long-term success. Liveaction stereoscopic films have historically been more time-consuming, costly, and creatively-limiting than 2D films - thus a need arises for a live-action 3D filmmaking process which minimizes such limitations. A unique 'systematized' what-you-see-is-what-you-get (WYSIWYG) pipeline is described which allows the efficient, intuitive and accurate capture and integration of 3D and 2D elements from multiple shoots and sources - both live-action and CGI. Throughout this pipeline, digital tools utilize a consistent algorithm to provide meaningful and accurate visual depth references with respect to the viewing audience in the target theater environment. This intuitive, visual approach introduces efficiency and creativity to the 3D filmmaking process by eliminating both the need for a 'mathematician mentality' of spreadsheets and calculators, as well as any trial and error guesswork, while enabling the most comfortable, 'pixel-perfect', artifact-free 3D product possible.

  11. Parallax distribution for ease of viewing in stereoscopic HDTV

    NASA Astrophysics Data System (ADS)

    Ide, Shinji; Yamanoue, Hirokazu; Okui, Makoto; Okano, Fumio; Bitou, Mineo; Terashima, Nobuyoshi

    2002-05-01

    In order to identify the conditions which make stereoscopic images easier to view, we analyzed the psychological effects using a stereoscopic HDTV system, and examined the relationship between this analysis and the parallax distribution patterns. First, we evaluated the impression of 3-D pictures of the standard 3-D test chart and past 3-D video programs using some evaluation terms. Two factors were thus extracted, the first related to the sense of presence and the second related to ease of viewing. Secondly, we applied principal component analysis to the parallax distribution of the stereoscopic images used in the subjective evaluation tests, in order to extract the features of the parallax distribution, then we examined the relationship between the factors and the features of the parallax distribution. The results indicated that the features of the parallax distribution are strongly related to ease of viewing, and for ease of viewing 3-D images, the upper part of the screen should be located further away from the viewer with less parallax irregularity, and the entire image should be positioned at the back.

  12. Optimal display conditions for quantitative analysis of stereoscopic cerebral angiograms

    SciTech Connect

    Charland, P.; Peters, T. |

    1996-10-01

    For several years the authors have been using a stereoscopic display as a tool in the planning of stereotactic neurosurgical techniques. This PC-based workstation allows the surgeon to interact with and view vascular images in three dimensions, as well as to perform quantitative analysis of the three-dimensional (3-D) space. Some of the perceptual issues relevant to the presentation of medical images on this stereoscopic display were addressed in five experiments. The authors show that a number of parameters--namely the shape, color, and depth cue, associated with a cursor--as well as the image filtering and observer position, have a role in improving the observer`s perception of a 3-D image and his ability to localize points within the stereoscopically presented 3-D image. However, an analysis of the results indicates that while varying these parameters can lead to an effect on the performance of individual observers, the effects are not consistent across observers, and the mean accuracy remains relatively constant under the different experimental conditions.

  13. Single-channel stereoscopic ophthalmology microscope based on TRD

    NASA Astrophysics Data System (ADS)

    Radfar, Edalat; Park, Jihoon; Lee, Sangyeob; Ha, Myungjin; Yu, Sungkon; Jang, Seulki; Jung, Byungjo

    2016-03-01

    A stereoscopic imaging modality was developed for the application of ophthalmology surgical microscopes. A previous study has already introduced a single-channel stereoscopic video imaging modality based on a transparent rotating deflector (SSVIM-TRD), in which two different view angles, image disparity, are generated by imaging through a transparent rotating deflector (TRD) mounted on a stepping motor and is placed in a lens system. In this case, the image disparity is a function of the refractive index and the rotation angle of TRD. Real-time single-channel stereoscopic ophthalmology microscope (SSOM) based on the TRD is improved by real-time controlling and programming, imaging speed, and illumination method. Image quality assessments were performed to investigate images quality and stability during the TRD operation. Results presented little significant difference in image quality in terms of stability of structural similarity (SSIM). A subjective analysis was performed with 15 blinded observers to evaluate the depth perception improvement and presented significant improvement in the depth perception capability. Along with all evaluation results, preliminary results of rabbit eye imaging presented that the SSOM could be utilized as an ophthalmic operating microscopes to overcome some of the limitations of conventional ones.

  14. On-the-wall stereoscopic liquid crystal display

    NASA Astrophysics Data System (ADS)

    Hattori, Tomohiko

    1995-03-01

    On-the-wall stereoscopic liquid crystal displays are described that permits the observation of a stereo pair by several persons simultaneously without the use of special glasses. One of the on- the-wall systems is composed of a high refresh rate transparent type color liquid crystal plate with a special back light unit and an infrared illuminating and the image taking system. The back light unit consists of a monochrome 2D display and a convex lens array. The unit distributes the light to the viewers' correct eyes. The system is a time-interface stereoscopic system. Another system consists of a transparent type color liquid crystal plate which polarizer must be micropolarizer with a special back light unit and an infrared illuminating and the image tracking system. The back light unit consists of a monochrome 2D liquid crystal display eliminated its polarizing analyzer and a convex lens array. The unit distributes the light to the viewers' correct eyes. The system is a spatial-multiplexing stereoscopic system. These systems were able to enlarge the image size and to shorten the thickness of the display.

  15. A simple method for measuring crosstalk in stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Weissman, Michael A.; Woods, Andrew J.

    2011-03-01

    Crosstalk (also known as "ghosting", "leakage", or "extinction"), a vitally important concept in stereoscopic 3D displays, has not been clearly defined or measured in the stereoscopic literature (Woods). In this paper, a mathematical definition is proposed which uses a "physical" approach. This derivation leads to a clear definition of leftview or right-view crosstalk and shows that 1), when the display's black level is not zero, it must be subtracted out and 2), when the source intensities are equal, crosstalk can be measured using observed intensities totally within the respective view. Next, a simple method of measuring crosstalk is presented, one that relies on only viewing a test chart on the display. No electronic or optical instruments are needed. Results of the use of the chart are presented, as well as optical measurements, which did not agree well with chart results. The main reason for the discrepancy is the difficulty of measuring very low light levels. With wide distribution, this tool can lead to the collection of useful performance information about 3D displays and, therefore, to the production of the best stereoscopic displays.

  16. The aqueous stability of a Mars salt analog: Instant Mars

    NASA Astrophysics Data System (ADS)

    Nuding, D. L.; Davis, R. D.; Gough, R. V.; Tolbert, M. A.

    2015-03-01

    Due to their stability in low-temperature conditions, aqueous salt solutions are the favored explanation for potential fluid features observed on present-day Mars. A salt analog was developed to closely match the individual cation and anion concentrations at the Phoenix landing site as reported by the Wet Chemistry Laboratory instrument. "Instant Mars" closely replicates correct relative concentrations of magnesium, calcium, potassium, sodium, perchlorate, chloride, and sulfate ions. A Raman microscope equipped with an environmental cellprobed liquid water uptake and loss by Instant Mars particles in a Mars relevant temperature and relative humidity (RH) environment. Our experiments reveal that Instant Mars particles can form stable, aqueous solutions starting at 56 ± 5% RH between 235 K and 243 K and persist as a metastable, aqueous solution at or above 13 ± 5% RH. Particle levitation using an optical trap examined the phase state and morphology of suspended Instant Mars particles exposed to changing water vapor conditions at room temperature. Levitation experiments indicate that water uptake began at 42 ± 8% RH for Instant Mars particles at 293 K. As RH is decreased at 293 K, the aqueous Instant Mars particles transition into a crystalline solid at 18 ± 7% RH. These combined results demonstrate that Instant Mars can take up water vapor from the surrounding environment and transition into a stable, aqueous solution. Furthermore, this aqueous Instant Mars solution can persist as a metastable, supersaturated solution in low-RH conditions.

  17. Lol: New Language and Spelling in Instant Messaging

    ERIC Educational Resources Information Center

    Varnhagen, Connie K.; McFall, G. Peggy; Pugh, Nicole; Routledge, Lisa; Sumida-MacDonald, Heather; Kwong, Trudy E.

    2010-01-01

    Written communication in instant messaging, text messaging, chat, and other forms of electronic communication appears to have generated a "new language" of abbreviations, acronyms, word combinations, and punctuation. In this naturalistic study, adolescents collected their instant messaging conversations for a 1-week period and then completed a…

  18. Cross-domain adaptation reveals that a common mechanism computes stereoscopic (cyclopean) and luminance plaid motion.

    PubMed

    Bowd, C; Donnelly, M; Shorter, S; Patterson, R

    2000-01-01

    Across three experiments, this study investigated the visual processing of moving stereoscopic plaid patterns (plaids created with cyclopean components defined by moving binocular disparity embedded in a dynamic random-dot stereogram). Results showed that adaptation to a moving stereoscopic plaid or its components affected the perceived coherence of a luminance test plaid, and vice versa. Cross-domain adaptation suggests that stereoscopic and luminance motion signals feed into a common pattern-motion mechanism, consistent with the idea that stereoscopic motion signals are computed early in the motion processing stream.

  19. A comparison of food and nutrient intake between instant noodle consumers and non-instant noodle consumers in Korean adults

    PubMed Central

    Park, Juyeon; Lee, Jung-Sug; Jang, Young Ai; Chung, Hae Rang

    2011-01-01

    Instant noodles are widely consumed in Asian countries. The Korean population consumed the largest quantity of instant noodles in the world in 2008. However, few studies have investigated the relationship between instant noodles and nutritional status in Koreans. The objective of this study was to examine the association between instant noodle consumption and food and nutrient intake in Korean adults. We used dietary data of 6,440 subjects aged 20 years and older who participated in the Korean National Health and Nutrition Examination Survey III. The average age of the instant noodle consumers (INC) was 36.2 and that of the non-instant noodle consumers (non-INC) was 44.9; men consumed more instant noodles than women (P < 0.001). With the exception of cereals and grain products, legumes, seaweeds, eggs, and milk and dairy products, INC consumed significantly fewer potatoes and starches, sugars, seeds and nuts, vegetables, mushrooms, fruits, seasonings, beverages, meats, fishes, and oils and fats compared with those in the non-INC group. The INC group showed significantly higher nutrient intake of energy, fat, sodium, thiamine, and riboflavin; however, the INC group showed a significantly lower intake of protein, calcium, phosphorus, iron, potassium, vitamin A, niacin, and vitamin C compared with those in the non-INC group. This study revealed that consuming instant noodles may lead to excessive intake of energy, fats, and sodium but may also cause increased intake of thiamine and riboflavin. Therefore, nutritional education helping adults to choose a balanced meal while consuming instant noodles should be implemented. Additionally, instant noodle manufacturers should consider nutritional aspects when developing new products. PMID:22125682

  20. Stereoscopic display technologies for FHD 3D LCD TV

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Sik; Ko, Young-Ji; Park, Sang-Moo; Jung, Jong-Hoon; Shestak, Sergey

    2010-04-01

    Stereoscopic display technologies have been developed as one of advanced displays, and many TV industrials have been trying commercialization of 3D TV. We have been developing 3D TV based on LCD with LED BLU (backlight unit) since Samsung launched the world's first 3D TV based on PDP. However, the data scanning of panel and LC's response characteristics of LCD TV cause interference among frames (that is crosstalk), and this makes 3D video quality worse. We propose the method to reduce crosstalk by LCD driving and backlight control of FHD 3D LCD TV.

  1. Stereoscopic PIV measurements of swirling flow entering a catalyst substrate

    SciTech Connect

    Persoons, T.; Vanierschot, M.; Van den Bulck, E.

    2008-09-15

    This experimental study investigates the stagnation region of a swirling flow entering an automotive catalyst substrate. A methodology is established using stereoscopic particle image velocimetry (PIV) to determine three-component velocity distributions up to 0.2 mm from the catalyst entrance face. In adverse conditions of strong out-of-plane velocity, PIV operating parameters are adjusted for maximum spatial correlation strength. The measurement distance to the catalyst is sufficiently small to observe radial flow spreading. A scaling analysis of the stagnation flow region provides a model for the flow uniformization as a function of the catalyst pressure drop. (author)

  2. Stereoscopic depth perception for robot vision: algorithms and architectures

    SciTech Connect

    Safranek, R.J.; Kak, A.C.

    1983-01-01

    The implementation of depth perception algorithms for computer vision is considered. In automated manufacturing, depth information is vital for tasks such as path planning and 3-d scene analysis. The presentation begins with a survey of computer algorithms for stereoscopic depth perception. The emphasis is on the Marr-Poggio paradigm of human stereo vision and its computer implementation. In addition, a stereo matching algorithm based on the relaxation labelling technique is examined. A computer architecture designed to efficiently implement stereo matching algorithms, an MIMD array interfaced to a global memory, is presented. 9 references.

  3. Perception of stereoscopic direct gaze: The effects of interaxial distance and emotional facial expressions.

    PubMed

    Hakala, Jussi; Kätsyri, Jari; Takala, Tapio; Häkkinen, Jukka

    2016-07-01

    Gaze perception has received considerable research attention due to its importance in social interaction. The majority of recent studies have utilized monoscopic pictorial gaze stimuli. However, a monoscopic direct gaze differs from a live or stereoscopic gaze. In the monoscopic condition, both eyes of the observer receive a direct gaze, whereas in live and stereoscopic conditions, only one eye receives a direct gaze. In the present study, we examined the implications of the difference between monoscopic and stereoscopic direct gaze. Moreover, because research has shown that stereoscopy affects the emotions elicited by facial expressions, and facial expressions affect the range of directions where an observer perceives mutual gaze-the cone of gaze-we studied the interaction effect of stereoscopy and facial expressions on gaze perception. Forty observers viewed stereoscopic images wherein one eye of the observer received a direct gaze while the other eye received a horizontally averted gaze at five different angles corresponding to five interaxial distances between the cameras in stimulus acquisition. In addition to monoscopic and stereoscopic conditions, the stimuli included neutral, angry, and happy facial expressions. The observers judged the gaze direction and mutual gaze of four lookers. Our results show that the mean of the directions received by the left and right eyes approximated the perceived gaze direction in the stereoscopic semidirect gaze condition. The probability of perceiving mutual gaze in the stereoscopic condition was substantially lower compared with monoscopic direct gaze. Furthermore, stereoscopic semidirect gaze significantly widened the cone of gaze for happy facial expressions.

  4. Construction of an instant structured illumination microscope

    PubMed Central

    Curd, Alistair; Cleasby, Alexa; Makowska, Katarzyna; York, Andrew; Shroff, Hari; Peckham, Michelle

    2015-01-01

    A challenge in biological imaging is to capture high-resolution images at fast frame rates in live cells. The “instant structured illumination microscope” (iSIM) is a system designed for this purpose. Similarly to standard structured illumination microscopy (SIM), an iSIM provides a twofold improvement over widefield microscopy, in x, y and z, but also allows much faster image acquisition, with real-time display of super-resolution images. The assembly of an iSIM is reasonably complex, involving the combination and alignment of many optical components, including three micro-optics arrays (two lenslet arrays and an array of pinholes, all with a pitch of 222 μm) and a double-sided scanning mirror. In addition, a number of electronic components must be correctly controlled. Construction of the system is therefore not trivial, but is highly desirable, particularly for live-cell imaging. We report, and provide instructions for, the construction of an iSIM, including minor modifications to a previous design in both hardware and software. The final instrument allows us to rapidly acquire fluorescence images at rates faster than 100 fps, with approximately twofold improvement in resolution in both x–y and z; sub-diffractive biological features have an apparent size (full width at half maximum) of 145 nm (lateral) and 320 nm (axial), using a 1.49 NA objective and 488 nm excitation. PMID:26210400

  5. single-channel stereoscopic video imaging modality based on a transparent rotating deflector

    NASA Astrophysics Data System (ADS)

    Radfar, Edalat; Park, Jihoon; Jun, Eunkwon; Ha, Myungjin; Lee, Sangyeob; Yu, SungKon; Jang, Seul G.; Jung, Byungjo

    2015-03-01

    This paper introduces a stereoscopic video imaging modality based on a transparent rotating deflector (TRD). Sequential two-dimensional (2D) left and right images were obtained by rotating the TRD on a stepping motor synchronized with a complementary metal-oxide semiconductor camera, and the components of the imaging modality were controlled through general purpose input/output ports using a microcontroller unit. In this research, live stereoscopic videos were visualized on a personal computer by both active shutter 3D and passive polarization 3D methods. The imaging modality was characterized by evaluating the stereoscopic video image generation, rotation characteristics of the TRD. The level of 3D conception was estimated in terms of simplified human stereovision. The results show that singlechannel stereoscopic video imaging modality has the potential to become an economical compact stereoscopic device as the system components are amenable to miniaturization; and could be applied in a wide variety of fields.

  6. Evaluation of stereoscopic display with visual function and interview

    NASA Astrophysics Data System (ADS)

    Okuyama, Fumio

    1999-05-01

    The influence of binocular stereoscopic (3D) television display on the human eye were compared with one of a 2D display, using human visual function testing and interviews. A 40- inch double lenticular display was used for 2D/3D comparison experiments. Subjects observed the display for 30 minutes at a distance 1.0 m, with a combination of 2D material and one of 3D material. The participants were twelve young adults. Main optometric test with visual function measured were visual acuity, refraction, phoria, near vision point, accommodation etc. The interview consisted of 17 questions. Testing procedures were performed just before watching, just after watching, and forty-five minutes after watching. Changes in visual function are characterized as prolongation of near vision point, decrease of accommodation and increase in phoria. 3D viewing interview results show much more visual fatigue in comparison with 2D results. The conclusions are: 1) change in visual function is larger and visual fatigue is more intense when viewing 3D images. 2) The evaluation method with visual function and interview proved to be very satisfactory for analyzing the influence of stereoscopic display on human eye.

  7. Analysis of Performance of Stereoscopic-Vision Software

    NASA Technical Reports Server (NTRS)

    Kim, Won; Ansar, Adnan; Steele, Robert; Steinke, Robert

    2007-01-01

    A team of JPL researchers has analyzed stereoscopic vision software and produced a document describing its performance. This software is of the type used in maneuvering exploratory robotic vehicles on Martian terrain. The software in question utilizes correlations between portions of the images recorded by two electronic cameras to compute stereoscopic disparities, which, in conjunction with camera models, are used in computing distances to terrain points to be included in constructing a three-dimensional model of the terrain. The analysis included effects of correlation- window size, a pyramidal image down-sampling scheme, vertical misalignment, focus, maximum disparity, stereo baseline, and range ripples. Contributions of sub-pixel interpolation, vertical misalignment, and foreshortening to stereo correlation error were examined theoretically and experimentally. It was found that camera-calibration inaccuracy contributes to both down-range and cross-range error but stereo correlation error affects only the down-range error. Experimental data for quantifying the stereo disparity error were obtained by use of reflective metrological targets taped to corners of bricks placed at known positions relative to the cameras. For the particular 1,024-by-768-pixel cameras of the system analyzed, the standard deviation of the down-range disparity error was found to be 0.32 pixel.

  8. Video retargeting for stereoscopic content under 3D viewing constraints

    NASA Astrophysics Data System (ADS)

    Chamaret, C.; Boisson, G.; Chevance, C.

    2012-03-01

    The imminent deployment of new devices such as TV, tablet, smart phone supporting stereoscopic display creates a need for retargeting the content. New devices bring their own aspect ratio and potential small screen size. Aspect ratio conversion becomes mandatory and an automatic solution will be of high value especially if it maximizes the visual comfort. Some issues inherent to 3D domain are considered in this paper: no vertical disparity, no object having negative disparity (outward perception) on the border of the cropping window. A visual attention model is applied on each view and provides saliency maps with most attractive pixels. Dedicated 3D retargeting correlates the 2D attention maps for each view as well as additional computed information to ensure the best cropping window. Specific constraints induced by 3D experience influence the retargeted window through the map computation presenting objects that should not be cropped. The comparison with original content of 2:35 ratio having black stripes provide limited 3D experience on TV screen, while the automatic cropping and exploitation of full screen show more immersive experience. The proposed system is fully automatic, ensures a good final quality without missing fundamental parts for the global understanding of the scene. Eye-tracking data recorded on stereoscopic content have been confronted to retargeted window in order to ensure that the most attractive areas are inside the final video.

  9. Study of compact stereoscopic system for target distance estimation

    NASA Astrophysics Data System (ADS)

    Bankman, Daniel J.

    2006-05-01

    Distance measurement is necessary in a variety of fields, including targeting, surveillance, reconnaissance, robotics, and cartography. Today, the most commonly used method for distance measurement is laser ranging. However, laser rangers being active systems require more energy and cost more than passive systems, and they can be detected by the adversary. Stereoscopic vision, a passive system, requires low levels of power and allows covert operation. This study considers stereoscopic vision with a compact, portable system, and investigates its essential parameters that can be optimized for accurate distance measurement. The main parameters addressed in this study are the distance between the two cameras, the kernel size used for correlation between the two images, and the quality of the image measured by the standard deviation of pixel values. The distance estimation accuracy is determined as a function of these parameters and the range to target. To represent a compact, portable system, the study considered parallel camera pairs placed 6 inches or 12 inches apart. Using small, visible light digital cameras, the slant range measurement error is less than 3% with 12 inches camera spacing, and a correlation kernel of 30 pixels in width. Larger camera spacing and shorter ranges to target increase the disparity and decrease the distance estimate error. Analytical error predictions explain the experimental results.

  10. Vergence eye movements are not essential for stereoscopic depth.

    PubMed

    Lugtigheid, Arthur J; Wilcox, Laurie M; Allison, Robert S; Howard, Ian P

    2014-02-01

    The brain receives disparate retinal input owing to the separation of the eyes, yet we usually perceive a single fused world. This is because of complex interactions between sensory and oculomotor processes that quickly act to reduce excessive retinal disparity. This implies a strong link between depth perception and fusion, but it is well established that stereoscopic depth percepts are also obtained from stimuli that produce double images. Surprisingly, the nature of depth percepts from such diplopic stimuli remains poorly understood. Specifically, despite long-standing debate it is unclear whether depth under diplopia is owing to the retinal disparity (directly), or whether the brain interprets signals from fusional vergence responses to large disparities (indirectly). Here, we addressed this question using stereoscopic afterimages, for which fusional vergence cannot provide retinal feedback about depth. We showed that observers could reliably recover depth sign and magnitude from diplopic afterimages. In addition, measuring vergence responses to large disparity stimuli revealed that that the sign and magnitude of vergence responses are not systematically related to the target disparity, thus ruling out an indirect explanation of our results. Taken together, our research provides the first conclusive evidence that stereopsis is a direct process, even for diplopic targets.

  11. Matching and correlation computations in stereoscopic depth perception.

    PubMed

    Doi, Takahiro; Tanabe, Seiji; Fujita, Ichiro

    2011-03-02

    A fundamental task of the visual system is to infer depth by using binocular disparity. To encode binocular disparity, the visual cortex performs two distinct computations: one detects matched patterns in paired images (matching computation); the other constructs the cross-correlation between the images (correlation computation). How the two computations are used in stereoscopic perception is unclear. We dissociated their contributions in near/far discrimination by varying the magnitude of the disparity across separate sessions. For small disparity (0.03°), subjects performed at chance level to a binocularly opposite-contrast (anti-correlated) random-dot stereogram (RDS) but improved their performance with the proportion of contrast-matched (correlated) dots. For large disparity (0.48°), the direction of perceived depth reversed with an anti-correlated RDS relative to that for a correlated one. Neither reversed nor normal depth was perceived when anti-correlation was applied to half of the dots. We explain the decision process as a weighted average of the two computations, with the relative weight of the correlation computation increasing with the disparity magnitude. We conclude that matching computation dominates fine depth perception, while both computations contribute to coarser depth perception. Thus, stereoscopic depth perception recruits different computations depending on the disparity magnitude.

  12. Influence of sonic noise on human stereoscopic depth perception.

    PubMed

    Hermann, E R; Hesse, C S; Hoyle, E R; Leopold, A C; Standard, J J

    1979-05-01

    Scientific establishment of the no-effect response to finite levels of exposure to a physical or chemical agent is indeed a rigorous exercise and is frequently controversial. In earlier research by Slutsky under direction of the senior author, a statistically significant increase in stereoscopic depth perception error was noted among 24 test subjects exposed to high intensity noise. Additional extensive research reported in this paper indicates that error in stereoscopic depth perception is not significantly altered by exposure to continuous white noise of short duration at levels ranging from 70 to 115 dBA. Furthernore, exposure of humans for periods of a few minutes to white noise in octave bands centered on 250 Hz, 1000 Hz, 4 kHz and 16 kHz at 115 dB does not affect their depth perception measured by the Howard-Dolman test. A comprehensive analysis of depth perception errors measured under noise exposure conditions (n = 4040) in comparison with those obtained under control conditions (n = 1430) produced a mean change in error of -0.38 mm, a statistically insignificant difference (p = 0.17). Even if such an error were attributable to high level noise, it should be noted that minus sign designates an improvement of depth perception in noise and that it is difficult to imagine visual tasks in which change in error of +/-0.38 mm at a distance of 6.0 meters is meaningful. PMID:463754

  13. Stereoscopic Movies for Teaching and Learning of Astronomy

    NASA Astrophysics Data System (ADS)

    Hayashi, Mitsuru; Kato, Tsunehiko N.; Takeda, Takaaaki; Kokubo, Eiichiro; Miura, Hitoshi; Takahei, Toshiyuki; Miyama, Shoken M.; Kaifu, Norio

    To attract the interest of the public in astronomy we visualize data obtained through simulations by using super computers and observations by using state-of -the-art facilities for example the SUBARU Telescope in the virtual reality system. The system is composed of three soft screens. We use two PC's two DLP projectors with circular polarization filters and one mirror for each screen to realize stereoscopic projection. By wearing glasses of circular polarization filters we can experience immersiveness in the system. Six PC's are connected by using optical fiber cable(1Gbps). Especially we developed the software for synchronization and realized stereoscopic movies(15-30 frames per second). In addition to teaching and learning of astronomy we also utilize the system above for public relations and science itself in NAO Mitaka. The system can provide scientists with the point of view we cannot realize on the earth. We are planning to improve the contents easier for the public to understand and distribute the contents to museums and educational institutions through networks for example Super SINET(the internet backbone connects institutes at 10Gbps) in 2003 in addition to monthly exhibition in NAOMitaka

  14. Antimutagenicity and catechin content of soluble instant teas.

    PubMed

    Constable, A; Varga, N; Richoz, J; Stadler, R H

    1996-03-01

    The antimutagenic properties of soluble instant teas were examined using the bacterial Ames assay. Inhibition of the numbers of revertants induced from a number of known mutagens indicates that aqueous extracts of instant teas have antimutagenic activity and antioxidative properties, and can inhibit nitrosation reactions. Despite a significant reduction in the amounts of major green tea catechins, quantified using reversed-phase HPLC with electro-chemical detection, no differences in antimutagenicity were observed between the instant teas, a black fermented tea and a green tea. Oxidation of polyphenolic compounds which occurs during the production of instant tea does not therefore decrease the antioxidant, free radical scavenging and antimutagenic properties. This suggests that catechins are not the only compounds responsible for the protective effects of teas. PMID:8671737

  15. Instant slides of radiographs for lectures.

    PubMed

    Rothstein, S G; Stewart, P L

    1989-10-01

    High quality slides of radiographs may be made with a simple, fast, and inexpensive technique using Kodak Rapid Process Copy film. Lecture presentations may include a slide of a pertinent plain radiograph, computed tomography (CT) scan, or magnetic resonance imaging (MRI). Although these slides may be made with a 35 mm SLR camera and flash or with a 35 mm SLR camera and a lighted viewbox, an alternative method is available that is easy to perform, inexpensive, and can produce quality slides in as little as 30 minutes. PMID:2477785

  16. Cosmic origins: experiences making a stereoscopic 3D movie

    NASA Astrophysics Data System (ADS)

    Holliman, Nick

    2010-02-01

    Context: Stereoscopic 3D movies are gaining rapid acceptance commercially. In addition our previous experience with the short 3D movie "Cosmic Cookery" showed that there is great public interest in the presentation of cosmology research using this medium. Objective: The objective of the work reported in this paper was to create a three-dimensional stereoscopic movie describing the life of the Milky way galaxy. This was a technical and artistic exercise to take observed and simulated data from leading scientists and produce a short (six minute) movie that describes how the Milky Way was created and what happens in its future. The initial target audience was the visitors to the Royal Society's 2009 Summer Science Exhibition in central London, UK. The movie is also intended to become a presentation tool for scientists and educators following the exhibition. Apparatus: The presentation and playback systems used consisted of off-the shelf devices and software. The display platform for the Royal Society presentation was a RealD LP Pro switch used with a DLP projector to rear project a 4 metre diagonal image. The LP Pro enables the use of cheap disposable linearly polarising glasses so that the high turnover rate of the audience (every ten minutes at peak times) could be sustained without needing delays to clean the glasses. The playback system was a high speed PC with an external 8Tb RAID driving the projectors at 30Hz per eye, the Lightspeed DepthQ software was used to decode and generate the video stream. Results: A wide range of tools were used to render the image sequences, ranging from commercial to custom software. Each tool was able to produce a stream of 1080p images in stereo at 30fps. None of the rendering tools used allowed precise calibration of the stereo effect at render time and therefore all sequences were tuned extensively in a trial and error process until the stereo effect was acceptable and supported a comfortable viewing experience. Conclusion: We

  17. Disparity modifications and the emotional effects of stereoscopic images

    NASA Astrophysics Data System (ADS)

    Kawai, Takashi; Atsuta, Daiki; Tomiyama, Yuya; Kim, Sanghyun; Morikawa, Hiroyuki; Mitsuya, Reiko; Häkkinen, Jukka

    2014-03-01

    This paper describes a study that focuses on disparity changes in emotional scenes of stereoscopic (3D) images, in which an examination of the effects on pleasant and arousal was carried out by adding binocular disparity to 2D images that evoke specific emotions, and applying disparity modification based on the disparity analysis of famous 3D movies. From the results of the experiment, for pleasant, a significant difference was found only for the main effect of the emotions. On the other hand, for arousal, there was a trend of increasing the evaluation values in the order 2D condition, 3D condition and 3D condition applied the disparity modification for happiness, surprise, and fear. This suggests the possibility that binocular disparity and the modification affect arousal.

  18. Multiple-view stereoscopic line-scan imaging

    NASA Astrophysics Data System (ADS)

    Evans, J. Paul O.; Hon, Hock W.

    2002-05-01

    A novel multiple view line-scan imaging technique that can be applied to transmission x-ray imaging as well as reflected light cameras is presented. In either case an area array image sensor is treated as a contiguous set of precisely arranged line-scan devices utilizing a single perspective center. IN the case of reflected light the perspective center is the nodal point of a lens whilst in the x-ray case it is the focal spot of an x-ray source. The line-scan images are accumulated in digital memory whilst the object under inspection is linearly translated through the field of view of the camera. In this way a number of perspective images, typically 6 to 16 are produced. The 3D information inherent in the perspective views can be visualized as a smooth object rotation or as a dynamic binocular stereoscopic sequence of views.

  19. Visual perception and stereoscopic imaging: an artist's perspective

    NASA Astrophysics Data System (ADS)

    Mason, Steve

    2015-03-01

    This paper continues my 2014 February IS and T/SPIE Convention exploration into the relationship of stereoscopic vision and consciousness (90141F-1). It was proposed then that by using stereoscopic imaging people may consciously experience, or see, what they are viewing and thereby help make them more aware of the way their brains manage and interpret visual information. Environmental imaging was suggested as a way to accomplish this. This paper is the result of further investigation, research, and follow-up imaging. A show of images, that is a result of this research, allows viewers to experience for themselves the effects of stereoscopy on consciousness. Creating dye-infused aluminum prints while employing ChromaDepth® 3D glasses, I hope to not only raise awareness of visual processing but also explore the differences and similarities between the artist and scientist―art increases right brain spatial consciousness, not only empirical thinking, while furthering the viewer's cognizance of the process of seeing. The artist must abandon preconceptions and expectations, despite what the evidence and experience may indicate in order to see what is happening in his work and to allow it to develop in ways he/she could never anticipate. This process is then revealed to the viewer in a show of work. It is in the experiencing, not just from the thinking, where insight is achieved. Directing the viewer's awareness during the experience using stereoscopic imaging allows for further understanding of the brain's function in the visual process. A cognitive transformation occurs, the preverbal "left/right brain shift," in order for viewers to "see" the space. Using what we know from recent brain research, these images will draw from certain parts of the brain when viewed in two dimensions and different ones when viewed stereoscopically, a shift, if one is looking for it, which is quite noticeable. People who have experienced these images in the context of examining their own

  20. Stereoscopic augmented reality with pseudo-realistic global illumination effects

    NASA Astrophysics Data System (ADS)

    de Sorbier, Francois; Saito, Hideo

    2014-03-01

    Recently, augmented reality has become very popular and has appeared in our daily life with gaming, guiding systems or mobile phone applications. However, inserting object in such a way their appearance seems natural is still an issue, especially in an unknown environment. This paper presents a framework that demonstrates the capabilities of Kinect for convincing augmented reality in an unknown environment. Rather than pre-computing a reconstruction of the scene like proposed by most of the previous method, we propose a dynamic capture of the scene that allows adapting to live changes of the environment. Our approach, based on the update of an environment map, can also detect the position of the light sources. Combining information from the environment map, the light sources and the camera tracking, we can display virtual objects using stereoscopic devices with global illumination effects such as diffuse and mirror reflections, refractions and shadows in real time.

  1. UHECR mass composition measurement at Telescope Array via stereoscopic observation

    NASA Astrophysics Data System (ADS)

    Stroman, Thomas; Telescope Array Collaboration

    2015-04-01

    The masses of primary ultra-high-energy cosmic-ray (UHECR) nuclei cannot be measured directly on an individual basis, but constraints on the chemical composition can be inferred from the distributions of observable properties. The atmospheric slant depth at which a UHECR-induced extensive air shower reaches its maximum number of particles, Xmax, is particularly sensitive to the mass of the incident nucleus, occurring earlier in the shower's longitudinal development for heavier nuclei at a given energy. The Telescope Array in west-central Utah, the northern hemisphere's largest UHECR detector, is equipped for accurate Xmax and energy measurements via stereoscopic fluorescence observation. Using data from seven years of operation, we will present Xmax distributions at several energies E >10 18 . 2eV , and compare them to distributions predicted by detailed detector simulations under an assortment of assumed UHECR compositions and high-energy hadronic interaction models.

  2. 3-D Target Location from Stereoscopic SAR Images

    SciTech Connect

    DOERRY,ARMIN W.

    1999-10-01

    SAR range-Doppler images are inherently 2-dimensional. Targets with a height offset lay over onto offset range and azimuth locations. Just which image locations are laid upon depends on the imaging geometry, including depression angle, squint angle, and target bearing. This is the well known layover phenomenon. Images formed with different aperture geometries will exhibit different layover characteristics. These differences can be exploited to ascertain target height information, in a stereoscopic manner. Depending on the imaging geometries, height accuracy can be on the order of horizontal position accuracies, thereby rivaling the best IFSAR capabilities in fine resolution SAR images. All that is required for this to work are two distinct passes with suitably different geometries from any plain old SAR.

  3. Stereoscopic, Force-Feedback Trainer For Telerobot Operators

    NASA Technical Reports Server (NTRS)

    Kim, Won S.; Schenker, Paul S.; Bejczy, Antal K.

    1994-01-01

    Computer-controlled simulator for training technicians to operate remote robots provides both visual and kinesthetic virtual reality. Used during initial stage of training; saves time and expense, increases operational safety, and prevents damage to robots by inexperienced operators. Computes virtual contact forces and torques of compliant robot in real time, providing operator with feel of forces experienced by manipulator as well as view in any of three modes: single view, two split views, or stereoscopic view. From keyboard, user specifies force-reflection gain and stiffness of manipulator hand for three translational and three rotational axes. System offers two simulated telerobotic tasks: insertion of peg in hole in three dimensions, and removal and insertion of drawer.

  4. Three-dimensional plasmonic stereoscopic prints in full colour

    NASA Astrophysics Data System (ADS)

    Goh, Xiao Ming; Zheng, Yihan; Tan, Shawn J.; Zhang, Lei; Kumar, Karthik; Qiu, Cheng-Wei; Yang, Joel K. W.

    2014-11-01

    Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies.

  5. Three-dimensional plasmonic stereoscopic prints in full colour.

    PubMed

    Goh, Xiao Ming; Zheng, Yihan; Tan, Shawn J; Zhang, Lei; Kumar, Karthik; Qiu, Cheng-Wei; Yang, Joel K W

    2014-11-04

    Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies.

  6. Clinical Assessment of Stereoacuity and 3-D Stereoscopic Entertainment

    PubMed Central

    Tidbury, Laurence P.; Black, Robert H.; O’Connor, Anna R.

    2015-01-01

    Abstract Background/Aims: The perception of compelling depth is often reported in individuals where no clinically measurable stereoacuity is apparent. We aim to investigate the potential cause of this finding by varying the amount of stereopsis available to the subject, and assessing their perception of depth viewing 3-D video clips and a Nintendo 3DS. Methods: Monocular blur was used to vary interocular VA difference, consequently creating 4 levels of measurable binocular deficit from normal stereoacuity to suppression. Stereoacuity was assessed at each level using the TNO, Preschool Randot®, Frisby, the FD2, and Distance Randot®. Subjects also completed an object depth identification task using the Nintendo 3DS, a static 3DTV stereoacuity test, and a 3-D perception rating task of 6 video clips. Results: As intraocular VA differences increased, stereoacuity of the 57 subjects (aged 16–62 years) decreased (eg, 110”, 280”, 340”, and suppression). The ability to correctly identify depth on the Nintendo 3DS remained at 100% until suppression of one eye occurred. The perception of a compelling 3-D effect when viewing the video clips was rated high until suppression of one eye occurred, where the 3-D effect was still reported as fairly evident. Conclusion: If an individual has any level of measurable stereoacuity, the perception of 3-D when viewing stereoscopic entertainment is present. The presence of motion in stereoscopic video appears to provide cues to depth, where static cues are not sufficient. This suggests there is a need for a dynamic test of stereoacuity to be developed, to allow fully informed patient management decisions to be made. PMID:26669421

  7. Many-core computing for space-based stereoscopic imaging

    NASA Astrophysics Data System (ADS)

    McCall, Paul; Torres, Gildo; LeGrand, Keith; Adjouadi, Malek; Liu, Chen; Darling, Jacob; Pernicka, Henry

    The potential benefits of using parallel computing in real-time visual-based satellite proximity operations missions are investigated. Improvements in performance and relative navigation solutions over single thread systems can be achieved through multi- and many-core computing. Stochastic relative orbit determination methods benefit from the higher measurement frequencies, allowing them to more accurately determine the associated statistical properties of the relative orbital elements. More accurate orbit determination can lead to reduced fuel consumption and extended mission capabilities and duration. Inherent to the process of stereoscopic image processing is the difficulty of loading, managing, parsing, and evaluating large amounts of data efficiently, which may result in delays or highly time consuming processes for single (or few) processor systems or platforms. In this research we utilize the Single-Chip Cloud Computer (SCC), a fully programmable 48-core experimental processor, created by Intel Labs as a platform for many-core software research, provided with a high-speed on-chip network for sharing information along with advanced power management technologies and support for message-passing. The results from utilizing the SCC platform for the stereoscopic image processing application are presented in the form of Performance, Power, Energy, and Energy-Delay-Product (EDP) metrics. Also, a comparison between the SCC results and those obtained from executing the same application on a commercial PC are presented, showing the potential benefits of utilizing the SCC in particular, and any many-core platforms in general for real-time processing of visual-based satellite proximity operations missions.

  8. Wide-Field-of-View, High-Resolution, Stereoscopic Imager

    NASA Technical Reports Server (NTRS)

    Prechtl, Eric F.; Sedwick, Raymond J.

    2010-01-01

    A device combines video feeds from multiple cameras to provide wide-field-of-view, high-resolution, stereoscopic video to the user. The prototype under development consists of two camera assemblies, one for each eye. One of these assemblies incorporates a mounting structure with multiple cameras attached at offset angles. The video signals from the cameras are fed to a central processing platform where each frame is color processed and mapped into a single contiguous wide-field-of-view image. Because the resolution of most display devices is typically smaller than the processed map, a cropped portion of the video feed is output to the display device. The positioning of the cropped window will likely be controlled through the use of a head tracking device, allowing the user to turn his or her head side-to-side or up and down to view different portions of the captured image. There are multiple options for the display of the stereoscopic image. The use of head mounted displays is one likely implementation. However, the use of 3D projection technologies is another potential technology under consideration, The technology can be adapted in a multitude of ways. The computing platform is scalable, such that the number, resolution, and sensitivity of the cameras can be leveraged to improve image resolution and field of view. Miniaturization efforts can be pursued to shrink the package down for better mobility. Power savings studies can be performed to enable unattended, remote sensing packages. Image compression and transmission technologies can be incorporated to enable an improved telepresence experience.

  9. New principles in nuclear medicine imaging: a full aperture stereoscopic imaging technique.

    PubMed

    Strocovsky, Sergio G; Otero, Dino

    2010-01-01

    In nuclear medicine, images of planar scintigraphy and single photon emission computerized tomography (SPECT) obtained through gamma camera (GC) appear to be blurred. Alternatively, coded aperture imaging (CAI) can surpass the quality of GC images, but still it is not extensively used due to the decoding complexity of some images and the difficulty in controlling the noise. Summing up, the images obtained through GC are low quality and it is still difficult to implement CAI technique. Here we present a full aperture imaging (FAI) technique which overcomes the problems of CAI ordinary systems. The gamma radiation transmitted through a large single aperture is edge-encoded, taking advantage of the fact that nuclear radiation is spatially incoherent. The novel technique is tested by means of Monte Carlo method with simple and complex sources. Spatial resolution tests and parallax tests of GC versus FAI were made, and three-dimensional capacities of GC versus FAI were analyzed. Simulations have allowed comparison of both techniques under ideal, identical conditions. The results show that FAI technique has greater sensitivity (approximately 100 times) and greater spatial resolution (>2.6 times at 40 cm source-detector distance) than that of GC. FAI technique allows to obtain images with typical resolution of GC short source-detector distance but at longer source-detector distance. The FAI decoding algorithm simultaneously reconstructs four different projections, while GC produces only one projection per acquisition. Our results show it is possible to apply an extremely simple encoded imaging technique, and get three-dimensional radioactivity information. Thus GC-based systems could be substituted, given that FAI technique is simple and it produces four images which may feed stereoscopic systems, substituting in some cases, tomographic reconstructions.

  10. Stereoscopic displays and applications; Proceedings of the Meeting, Santa Clara, CA, Feb. 12-14, 1990

    NASA Technical Reports Server (NTRS)

    Merritt, John O. (Editor); Fisher, Scott S. (Editor)

    1990-01-01

    The present conference discusses topics in the fields of stereoscopic displays' user interfaces, three-dimensional (TD) visualization, novel TD displays, and applications of stereoscopic displays. Attention is given to TD cockpit displays, novel computational control techniques for stereo TD displays, characterization of higher-dimensional presentation techniques, volume visualization on a stereoscopic display, and stereoscopic displays for terrain-data base visualization. Also discussed are the experimental design of cyberspaces, a volumetric environment for interactive design of three-dimensional objects, videotape recording of TD TV images, remote manipulator tasks rendered possible by stereo TV, TD endoscopy based on alternating-frame technology, and advancements in computer-generated barrier-strip autostereography.

  11. Analysis of brain activity and response during monoscopic and stereoscopic visualization

    NASA Astrophysics Data System (ADS)

    Calore, Enrico; Folgieri, Raffaella; Gadia, Davide; Marini, Daniele

    2012-03-01

    Stereoscopic visualization in cinematography and Virtual Reality (VR) creates an illusion of depth by means of two bidimensional images corresponding to different views of a scene. This perceptual trick is used to enhance the emotional response and the sense of presence and immersivity of the observers. An interesting question is if and how it is possible to measure and analyze the level of emotional involvement and attention of the observers during a stereoscopic visualization of a movie or of a virtual environment. The research aims represent a challenge, due to the large number of sensorial, physiological and cognitive stimuli involved. In this paper we begin this research by analyzing possible differences in the brain activity of subjects during the viewing of monoscopic or stereoscopic contents. To this aim, we have performed some preliminary experiments collecting electroencephalographic (EEG) data of a group of users using a Brain- Computer Interface (BCI) during the viewing of stereoscopic and monoscopic short movies in a VR immersive installation.

  12. Post-Delivery test report for light duty utility arm high resolution stereoscopic video system (HRSVS)

    SciTech Connect

    Pardini, A.F., Westinghouse Hanford

    1996-05-07

    This report documents the post delivery testing of the High Resolution Stereoscopic Video Camera System (HRSVS) LDUA system,designed for use by the Light Duty Utility Arm (LDUA) project.The post delivery test shows by demonstration that the high resolution stereoscopic video camera system is fully operational to perform the task of aligning the LDUA arm and mast with the entry riser during deployment operations within a Hanford Site waste tank.

  13. Operation and maintenance manual for the high resolution stereoscopic video camera system (HRSVS) system 6230

    SciTech Connect

    Pardini, A.F., Westinghouse Hanford

    1996-07-16

    The High Resolution Stereoscopic Video Cameral System (HRSVS),system 6230, is a stereoscopic camera system that will be used as an end effector on the LDUA to perform surveillance and inspection activities within Hanford waste tanks. It is attached to the LDUA by means of a Tool Interface Plate (TIP), which provides a feed through for all electrical and pneumatic utilities needed by the end effector to operate.

  14. Single-channel stereoscopic video imaging modality based on transparent rotating deflector.

    PubMed

    Radfar, Edalat; Jang, Won Hyuk; Freidoony, Leila; Park, Jihoon; Kwon, Kichul; Jung, Byungjo

    2015-10-19

    In this study, we developed a single-channel stereoscopic video imaging modality based on a transparent rotating deflector (TRD). Sequential two-dimensional (2D) left and right images were obtained through the TRD synchronized with a camera, and the components of the imaging modality were controlled by a microcontroller unit. The imaging modality was characterized by evaluating the stereoscopic video image generation, rotation of the TRD, heat generation by the stepping motor, and image quality and its stability in terms of the structural similarity index. The degree of depth perception was estimated and subjective analysis was performed to evaluate the depth perception improvement. The results show that the single-channel stereoscopic video imaging modality may: 1) overcome some limitations of conventional stereoscopic video imaging modalities; 2) be a potential economical compact stereoscopic imaging modality if the system components can be miniaturized; 3) be easily integrated into current 2D optical imaging modalities to produce a stereoscopic image; and 4) be applied to various medical and industrial fields.

  15. A Review on Stereoscopic 3D: Home Entertainment for the Twenty First Century

    NASA Astrophysics Data System (ADS)

    Karajeh, Huda; Maqableh, Mahmoud; Masa'deh, Ra'ed

    2014-12-01

    In the last few years, stereoscopic developed very rapidly and employed in many different fields such as entertainment. Due to the importance of entertainment aspect of stereoscopic 3D (S3D) applications, a review of the current state of S3D development in entertainment technology is conducted. In this paper, a novel survey of the stereoscopic entertainment aspects is presented by discussing the significant development of a 3D cinema, the major development of 3DTV, the issues related to 3D video content and 3D video games. Moreover, we reviewed some problems that can be caused in the viewers' visual system from watching stereoscopic contents. Some stereoscopic viewers are not satisfied as they are frustrated from wearing glasses, have visual fatigue, complain from unavailability of 3D contents, and/or complain from some sickness. Therefore, we will discuss stereoscopic visual discomfort and to what extend the viewer will have an eye fatigue while watching 3D contents or playing 3D games. The suggested solutions in the literature for this problem are discussed.

  16. Software-Assisted Depth Analysis of Optic Nerve Stereoscopic Images in Telemedicine.

    PubMed

    Xia, Tian; Patel, Shriji N; Szirth, Ben C; Kolomeyer, Anton M; Khouri, Albert S

    2016-01-01

    Background. Software guided optic nerve assessment can assist in process automation and reduce interobserver disagreement. We tested depth analysis software (DAS) in assessing optic nerve cup-to-disc ratio (VCD) from stereoscopic optic nerve images (SONI) of normal eyes. Methods. In a prospective study, simultaneous SONI from normal subjects were collected during telemedicine screenings using a Kowa 3Wx nonmydriatic simultaneous stereoscopic retinal camera (Tokyo, Japan). VCD was determined from SONI pairs and proprietary pixel DAS (Kowa Inc., Tokyo, Japan) after disc and cup contour line placement. A nonstereoscopic VCD was determined using the right channel of a stereo pair. Mean, standard deviation, t-test, and the intraclass correlation coefficient (ICCC) were calculated. Results. 32 patients had mean age of 40 ± 14 years. Mean VCD on SONI was 0.36 ± 0.09, with DAS 0.38 ± 0.08, and with nonstereoscopic 0.29 ± 0.12. The difference between stereoscopic and DAS assisted was not significant (p = 0.45). ICCC showed agreement between stereoscopic and software VCD assessment. Mean VCD difference was significant between nonstereoscopic and stereoscopic (p < 0.05) and nonstereoscopic and DAS (p < 0.005) recordings. Conclusions. DAS successfully assessed SONI and showed a high degree of correlation to physician-determined stereoscopic VCD. PMID:27190507

  17. Software-Assisted Depth Analysis of Optic Nerve Stereoscopic Images in Telemedicine

    PubMed Central

    Xia, Tian; Patel, Shriji N.; Szirth, Ben C.

    2016-01-01

    Background. Software guided optic nerve assessment can assist in process automation and reduce interobserver disagreement. We tested depth analysis software (DAS) in assessing optic nerve cup-to-disc ratio (VCD) from stereoscopic optic nerve images (SONI) of normal eyes. Methods. In a prospective study, simultaneous SONI from normal subjects were collected during telemedicine screenings using a Kowa 3Wx nonmydriatic simultaneous stereoscopic retinal camera (Tokyo, Japan). VCD was determined from SONI pairs and proprietary pixel DAS (Kowa Inc., Tokyo, Japan) after disc and cup contour line placement. A nonstereoscopic VCD was determined using the right channel of a stereo pair. Mean, standard deviation, t-test, and the intraclass correlation coefficient (ICCC) were calculated. Results. 32 patients had mean age of 40 ± 14 years. Mean VCD on SONI was 0.36 ± 0.09, with DAS 0.38 ± 0.08, and with nonstereoscopic 0.29 ± 0.12. The difference between stereoscopic and DAS assisted was not significant (p = 0.45). ICCC showed agreement between stereoscopic and software VCD assessment. Mean VCD difference was significant between nonstereoscopic and stereoscopic (p < 0.05) and nonstereoscopic and DAS (p < 0.005) recordings. Conclusions. DAS successfully assessed SONI and showed a high degree of correlation to physician-determined stereoscopic VCD. PMID:27190507

  18. Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.

    PubMed

    Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L

    2015-06-01

    Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.

  19. Effects of stereoscopic filming parameters and display duration on the subjective assessment of eye strain

    NASA Astrophysics Data System (ADS)

    IJsselsteijn, Wijnand A.; de Ridder, Huib; Vliegen, Joyce

    2000-05-01

    Despite many benefits that stereoscopic displays are known to have, there is evidence that stereoscopic displays can potentially cause discomfort to the viewer. The experiment reported in this paper was motivated by the need to quantify the potential subjective discomfort of viewing stereoscopic TV images. Observers provided direct subjective ratings of eye strain and quality in response to stereoscopic still images that varied in camera separation, convergence distance and focal length. Display duration of the images was varied between 1 an d15 seconds. Before and after the experiment, observers filled out a symptom checklist to assess any subjective discomfort resulting from the total experiment. Reported eye strain was on average around 'perceptible, but not annoying' for natural disparities. As disparity values increased reported eye strain increased to 'very annoying' and quality rating solved off and eventually dropped. This effect was most pronounced for the stereoscopic images that were produce using a short convergence distance. This effect may be attributed to an increase in keystone distortion in this condition. No significant effect of display duration was found. The results of the symptom checklist showed a slight increase in reported negative side-effects, with most observers reporting only mild symptoms of discomfort. Finally, our results showed that subjective stereoscopic image quality can be described as a function of reported eye strain and perceived depth.

  20. Can Turnitin Be Used to Provide Instant Formative Feedback?

    ERIC Educational Resources Information Center

    Rolfe, Vivien

    2011-01-01

    New students face the challenge of making a smooth transition between school and university, and with regards to academic practice, there are often gaps between student expectations and university requirements. This study supports the use of the plagiarism detection service Turnitin to give students instant feedback on essays to help improve…

  1. The Effect of Instant Messaging on Lecture Retention

    ERIC Educational Resources Information Center

    McVaugh, Nathan Kant

    2012-01-01

    The impact of instant message interruptions via computer on immediate lecture retention for college students was examined. While watching a 24-minute video of a classroom lecture, students received various numbers of related-to-lecture ("Is consistent use of the eye contact method necessary for success?") versus not-related-to lecture…

  2. Affordances and Text-Making Practices in Online Instant Messaging

    ERIC Educational Resources Information Center

    Lee, Carmen K.-M.

    2007-01-01

    This study examines the factors influencing language and script choice in instant messaging (IM), a form of real-time computer-mediated communication, in a multilingual setting. Grounded in the New Literacy Studies, the study understands IM as a social practice involving texts, encompassing a range of literacy practices, within which a subset…

  3. Young People's Everyday Literacies: The Language Features of Instant Messaging

    ERIC Educational Resources Information Center

    Haas, Christina; Takayoshi, Pamela

    2011-01-01

    In this article, we examine writing in the context of new communication technologies as a kind of everyday literacy. Using an inductive approach developed from grounded theory, we analyzed a 32,000-word corpus of college students' Instant Messaging (IM) exchanges. Through our analysis of this corpus, we identify a fifteen-item taxonomy of IM…

  4. AskNow Instant Messaging: Innovation in Virtual Reference

    ERIC Educational Resources Information Center

    Davis, Kate

    2007-01-01

    In late 2006, the National Library of Australia (NLA) implemented a trial Instant Messaging (IM) service that ran in parallel with the AskNow chat reference service for a six month period. The trial was a resounding success, proving both a demand for an IM service and the suitability of the medium for reference service provision in a collaborative…

  5. Teaching "Instant Experience" with Graphical Model Validation Techniques

    ERIC Educational Resources Information Center

    Ekstrøm, Claus Thorn

    2014-01-01

    Graphical model validation techniques for linear normal models are often used to check the assumptions underlying a statistical model. We describe an approach to provide "instant experience" in looking at a graphical model validation plot, so it becomes easier to validate if any of the underlying assumptions are violated.

  6. Lexical Cues of Interaction Involvement in Dyadic Instant Messaging Conversations

    ERIC Educational Resources Information Center

    Nguyen, Duyen T.; Fussell, Susan R.

    2014-01-01

    We explore how people express and interpret lexical cues of interaction involvement in dyadic conversations via instant messaging (IM) in two studies. In Study 1, an experiment with 60 participants, we manipulated level of involvement in a conversation with a distraction task. We examined how participants' uses of verbal cues such as pronouns…

  7. Stereoscopic camera system for live-action and sports productions

    NASA Astrophysics Data System (ADS)

    Adkins, Craig

    1997-05-01

    By all accounts I am a cowboy cameraman. I began my career as a ski bum in the Swiss Alps at the age of 18. Once I had picked up a Super 8 camera and filmed my first skiing sequence, the mold was pretty much set. I have concentrated my direction on shooting live action in extreme environments ever since. I shun the use of tripods and my experience in artificial lighting is minimal. My technical knowledge of the equipment and medium I use is limited to practical use dictated by weather and terrain conditions. When confronted with a frozen film gate in a raging blizzard, perched atop a 200 foot drop, there are only so many options. This brief personal history prefaces the underlying theme of the camera system I designed and have been using in the field for the past year. I do not claim to be a deep well of information on stereoscopic theory and technology nor a maverick inventor. Rather, I am someone who saw stereo video and realized it was a significant improvement in existing visual technology. The resulting experience I have gained from building a stereo video camera system is purely empirical, helped by other's shared insights and my own trial and error.

  8. Measurements of turbulent premixed flame dynamics using cinema stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Steinberg, Adam M.; Driscoll, James F.; Ceccio, Steven L.

    2008-06-01

    A new experimental method is described that provides high-speed movies of turbulent premixed flame wrinkling dynamics and the associated vorticity fields. This method employs cinema stereoscopic particle image velocimetry and has been applied to a turbulent slot Bunsen flame. Three-component velocity fields were measured with high temporal and spatial resolutions of 0.9 ms and 140 μm, respectively. The flame-front location was determined using a new multi-step method based on particle image gradients, which is described. Comparisons are made between flame fronts found with this method and simultaneous CH-PLIF images. These show that the flame contour determined corresponds well to the true location of maximum gas density gradient. Time histories of typical eddy-flame interactions are reported and several important phenomena identified. Outwardly rotating eddy pairs wrinkle the flame and are attenuated at they pass through the flamelet. Significant flame-generated vorticity is produced downstream of the wrinkled tip. Similar wrinkles are caused by larger groups of outwardly rotating eddies. Inwardly rotating pairs cause significant convex wrinkles that grow as the flame propagates. These wrinkles encounter other eddies that alter their behavior. The effects of the hydrodynamic and diffusive instabilities are observed and found to be significant contributors to the formation and propagation of wrinkles.

  9. Real-Time Depth Measurement In A Stereoscopic Television Display

    NASA Astrophysics Data System (ADS)

    Robinson, M.; Sood, S. C.

    1983-04-01

    A working prototype three-dimensional television display has been constructed and initial feasibility studies have been carried out. The system employs the time division technique which takes advantage of the interlace facility on the standard television display and incorporates electro-optic viewing spectacles for the observer. Improvements to the basic system have been carried out which include remotely triggered viewing spectacles, thus giving greater freedom of movement to the observer and also an increased switching rate to reduce the effects of flicker. It soon became apparent that a system containing an integral real time depth measurement facility would be attractive to potential users. The method used is the application of a photogrammetic technique to the display in order to provide a real time three dimensional viewing and depth measurement facility. Present available techniques involve processing a stereoscopic pair of photographs which introduces an obvious inherent time delay. For many applications a real time technique has advantages even though the depth resolution is unlikely to be as good as the standard photographic system.

  10. Re-engineering the stereoscope for the 21st Century

    NASA Astrophysics Data System (ADS)

    Kollin, Joel S.; Hollander, Ari J.

    2007-02-01

    While discussing the current state of stereo head-mounted and 3D projection displays, the authors came to the realization that flat-panel LCD displays offer higher resolution than projection for stereo display at a low (and continually dropping) cost. More specifically, where head-mounted displays of moderate resolution and field-of-view cost tens of thousands of dollars, we can achieve an angular resolution approaching that of the human eye with a field-of-view (FOV) greater than 90° for less than $1500. For many immersive applications head tracking is unnecessary and sometimes even undesirable, and a low cost/high quality wide FOV display may significantly increase the application space for 3D display. After outlining the problem and potential of this solution we describe the initial construction of a simple Wheatstone stereoscope using 24" LCD displays and then show engineering improvements that increase the FOV and usability of the system. The applicability of a high-immersion, high-resolution display for art, entertainment, and simulation is presented along with a content production system that utilizes the capabilities of the system. We then discuss the potential use of the system for VR pain control therapy, treatment of post-traumatic stress disorders and other serious games applications.

  11. User experience while viewing stereoscopic 3D television

    PubMed Central

    Read, Jenny C.A.; Bohr, Iwo

    2014-01-01

    3D display technologies have been linked to visual discomfort and fatigue. In a lab-based study with a between-subjects design, 433 viewers aged from 4 to 82 years watched the same movie in either 2D or stereo 3D (S3D), and subjectively reported on a range of aspects of their viewing experience. Our results suggest that a minority of viewers, around 14%, experience adverse effects due to viewing S3D, mainly headache and eyestrain. A control experiment where participants viewed 2D content through 3D glasses suggests that around 8% may report adverse effects which are not due directly to viewing S3D, but instead are due to the glasses or to negative preconceptions about S3D (the ‘nocebo effect'). Women were slightly more likely than men to report adverse effects with S3D. We could not detect any link between pre-existing eye conditions or low stereoacuity and the likelihood of experiencing adverse effects with S3D. Practitioner Summary: Stereoscopic 3D (S3D) has been linked to visual discomfort and fatigue. Viewers watched the same movie in either 2D or stereo 3D (between-subjects design). Around 14% reported effects such as headache and eyestrain linked to S3D itself, while 8% report adverse effects attributable to 3D glasses or negative expectations. PMID:24874550

  12. Temporal channels and disparity representations in stereoscopic depth perception.

    PubMed

    Doi, Takahiro; Takano, Maki; Fujita, Ichiro

    2013-11-26

    Stereoscopic depth perception is supported by a combination of correlation-based and match-based representations of binocular disparity. It also relies on both transient and sustained temporal channels of the visual system. Previous studies suggest that the relative contribution of the correlation-based representation (over the match-based representation) and the transient channel (over the sustained channel) to depth perception increases with the disparity magnitude. The mechanisms of the correlation-based and match-based representations may receive preferential inputs from the transient and sustained channels, respectively. We examined near/far discrimination by observers using random-dot stereograms refreshed at various rates. The relative contribution of the two representations was inferred by changing the fraction of dots that were contrast reversed between the two eyes. Both representations contributed to depth discrimination over the tested range of refresh rates. As the rate increased, the correlation-based representation increased its contribution to near/far discrimination. Another experiment revealed that the match-based representation was constructed by exploiting the variability in correlation-based disparity signals. Thus, the relative weight of the transient over sustained channel differs between the two representations. The correlation-based representation dominates depth perception with dynamic inputs. The match-based representation, which may be a nonlinear refinement of the correlation-based representation, exerts more influence on depth perception with slower inputs.

  13. Digital stereoscopic photography using StereoData Maker

    NASA Astrophysics Data System (ADS)

    Toeppen, John; Sykes, David

    2009-02-01

    Stereoscopic digital photography has become much more practical with the use of USB wired connections between a pair of Canon cameras using StereoData Maker software for precise synchronization. StereoPhoto Maker software is now used to automatically combine and align right and left image files to produce a stereo pair. Side by side images are saved as pairs and may be viewed using software that converts the images into the preferred viewing format at the time of display. Stereo images may be shared on the internet, displayed on computer monitors, autostereo displays, viewed on high definition 3D TVs, or projected for a group. Stereo photographers are now free to control composition using point and shoot settings, or are able to control shutter speed, aperture, focus, ISO, and zoom. The quality of the output depends on the developed skills of the photographer as well as their understanding of the software, human vision and the geometry they choose for their cameras and subjects. Observers of digital stereo images can zoom in for greater detail and scroll across large panoramic fields with a few keystrokes. The art, science, and methods of taking, creating and viewing digital stereo photos are presented in a historic and developmental context in this paper.

  14. 76 FR 69287 - National Instant Criminal Background Check System Section Agency Information Collection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... Federal Bureau of Investigation National Instant Criminal Background Check System Section Agency Information Collection Activities: Existing collection, comments requested the Voluntary Appeal File (VAF... Criminal Justice Information Services (CJIS) Division's National Instant Criminal Background Check...

  15. InstantScope: a low-cost whole slide imaging system with instant focal plane detection

    PubMed Central

    Guo, Kaikai; Liao, Jun; Bian, Zichao; Heng, Xin; Zheng, Guoan

    2015-01-01

    We report the development of a high-throughput whole slide imaging (WSI) system by adapting a cost-effective optomechanical add-on kit to existing microscopes. Inspired by the phase detection concept in professional photography, we attached two pinhole-modulated cameras at the eyepiece ports for instant focal plane detection. By adjusting the positions of the pinholes, we can effectively change the view angle for the sample, and as such, we can use the translation shift of the two pinhole-modulated images to identify the optimal focal position. By using a small pinhole size, the focal-plane-detection range is on the order of millimeter, orders of magnitude longer than the objective’s depth of field. We also show that, by analyzing the phase correlation of the pinhole-modulated images, we can determine whether the sample contains one thin section, folded sections, or multiple layers separated by certain distances – an important piece of information prior to a detailed z scan. In order to achieve system automation, we deployed a low-cost programmable robotic arm to perform sample loading and $14 stepper motors to drive the microscope stage to perform x-y scanning. Using a 20X objective lens, we can acquire a 2 gigapixel image with 14 mm by 8 mm field of view in 90 seconds. The reported platform may find applications in biomedical research, telemedicine, and digital pathology. It may also provide new insights for the development of high-content screening instruments. PMID:26417493

  16. Stereoscopic visualization and haptic technology used to create a virtual environment for remote surgery - biomed 2011.

    PubMed

    Bornhoft, J M; Strabala, K W; Wortman, T D; Lehman, A C; Oleynikov, D; Farritor, S M

    2011-01-01

    The objective of this research is to study the effectiveness of using a stereoscopic visualization system for performing remote surgery. The use of stereoscopic vision has become common with the advent of the da Vinci® system (Intuitive, Sunnyvale CA). This system creates a virtual environment that consists of a 3-D display for visual feedback and haptic tactile feedback, together providing an intuitive environment for remote surgical applications. This study will use simple in vivo robotic surgical devices and compare the performance of surgeons using the stereoscopic interfacing system to the performance of surgeons using one dimensional monitors. The stereoscopic viewing system consists of two cameras, two monitors, and four mirrors. The cameras are mounted to a multi-functional miniature in vivo robot; and mimic the depth perception of the actual human eyes. This is done by placing the cameras at a calculated angle and distance apart. Live video streams from the left and right cameras are displayed on the left and right monitors, respectively. A system of angled mirrors allows the left and right eyes to see the video stream from the left and right monitor, respectively, creating the illusion of depth. The haptic interface consists of two PHANTOM Omni® (SensAble, Woburn Ma) controllers. These controllers measure the position and orientation of a pen-like end effector with three degrees of freedom. As the surgeon uses this interface, they see a 3-D image and feel force feedback for collision and workspace limits. The stereoscopic viewing system has been used in several surgical training tests and shows a potential improvement in depth perception and 3-D vision. The haptic system accurately gives force feedback that aids in surgery. Both have been used in non-survival animal surgeries, and have successfully been used in suturing and gallbladder removal. Bench top experiments using the interfacing system have also been conducted. A group of participants completed

  17. Relationship between threshold and suprathreshold perception of position and stereoscopic depth.

    PubMed

    Patel, Saumil S; Bedell, Harold E; Tsang, Dorcas K; Ukwade, Michael T

    2009-04-01

    We seek to determine the relationship between threshold and suprathreshold perception for position offset and stereoscopic depth perception under conditions that elevate their respective thresholds. Two threshold-elevating conditions were used: (1) increasing the interline gap and (2) dioptric blur. Although increasing the interline gap increases position (Vernier) offset and stereoscopic disparity thresholds substantially, the perception of suprathreshold position offset and stereoscopic depth remains unchanged. Perception of suprathreshold position offset also remains unchanged when the Vernier threshold is elevated by dioptric blur. We show that such normalization of suprathreshold position offset can be attributed to the topographical-map-based encoding of position. On the other hand, dioptric blur increases the stereoscopic disparity thresholds and reduces the perceived suprathreshold stereoscopic depth, which can be accounted for by a disparity-computation model in which the activities of absolute disparity encoders are multiplied by a Gaussian weighting function that is centered on the horopter. Overall, the statement "equal suprathreshold perception occurs in threshold-elevated and unelevated conditions when the stimuli are equally above their corresponding thresholds" describes the results better than the statement "suprathreshold stimuli are perceived as equal when they are equal multiples of their respective threshold values."

  18. A new fast matching method for adaptive compression of stereoscopic images

    NASA Astrophysics Data System (ADS)

    Ortis, A.; Battiato, S.

    2015-03-01

    In the last few years, due to the growing use of stereoscopic images, much effort has been spent by the scientific community to develop algorithms for stereoscopic image compression. Stereo images represent the same scene from two different views, and therefore they typically contain a high degree of redundancy. It is then possible to implement some compression strategies devoted to exploit the intrinsic characteristics of the two involved images that are typically embedded in a MPO (Multi Picture Object) data format. MPO files represents a stereoscopic image by building a list of JPEG images. Our previous work introduced a simple block-matching approach to compute local residual useful to reconstruct during the decoding phase, stereoscopic images that maintain high perceptual quality; this allows to the encoder to force high level of compression at least for one of the two involved images. On the other hand the matching approach, based only on the similarity of the blocks, results rather inefficient. Starting from this point, the main contribution of this paper focuses on the improvement of both matching step effectiveness and its computational cost. Such alternative approach aims to greatly enhance matching step by exploiting the geometric properties of a pair of stereoscopic images. In this way we significantly reduce the complexity of the method without affecting results in terms of quality.

  19. Digital stereoscopic convergence where video games and movies for the home user meet

    NASA Astrophysics Data System (ADS)

    Schur, Ethan

    2009-02-01

    Today there is a proliferation of stereoscopic 3D display devices, 3D content, and 3D enabled video games. As we in the S-3D community bring stereoscopic 3D to the home user we have a real opportunity of using stereoscopic 3D to bridge the gap between exciting immersive games and home movies. But to do this, we cannot limit ourselves to current conceptions of gaming and movies. We need, for example, to imagine a movie that is fully rendered using avatars in a stereoscopic game environment. Or perhaps to imagine a pervasive drama where viewers can play too and become an essential part of the drama - whether at home or on the go on a mobile platform. Stereoscopic 3D is the "glue" that will bind these video and movie concepts together. As users feel more immersed, the lines between current media will blur. This means that we have the opportunity to shape the way that we, as humans, view and interact with each other, our surroundings and our most fundamental art forms. The goal of this paper is to stimulate conversation and further development on expanding the current gaming and home theatre infrastructures to support greatly-enhanced experiential entertainment.

  20. Stereoscopic Machine-Vision System Using Projected Circles

    NASA Technical Reports Server (NTRS)

    Mackey, Jeffrey R.

    2010-01-01

    A machine-vision system capable of detecting obstacles large enough to damage or trap a robotic vehicle is undergoing development. The system includes (1) a pattern generator that projects concentric circles of laser light forward onto the terrain, (2) a stereoscopic pair of cameras that are aimed forward to acquire images of the circles, (3) a frame grabber and digitizer for acquiring image data from the cameras, and (4) a single-board computer that processes the data. The system is being developed as a prototype of machine- vision systems to enable robotic vehicles ( rovers ) on remote planets to avoid craters, large rocks, and other terrain features that could capture or damage the vehicles. Potential terrestrial applications of systems like this one could include terrain mapping, collision avoidance, navigation of robotic vehicles, mining, and robotic rescue. This system is based partly on the same principles as those of a prior stereoscopic machine-vision system in which the cameras acquire images of a single stripe of laser light that is swept forward across the terrain. However, this system is designed to afford improvements over some of the undesirable features of the prior system, including the need for a pan-and-tilt mechanism to aim the laser to generate the swept stripe, ambiguities in interpretation of the single-stripe image, the time needed to sweep the stripe across the terrain and process the data from many images acquired during that time, and difficulty of calibration because of the narrowness of the stripe. In this system, the pattern generator does not contain any moving parts and need not be mounted on a pan-and-tilt mechanism: the pattern of concentric circles is projected steadily in the forward direction. The system calibrates itself by use of data acquired during projection of the concentric-circle pattern onto a known target representing flat ground. The calibration- target image data are stored in the computer memory for use as a

  1. Production of bioethanol and biodiesel using instant noodle waste.

    PubMed

    Yang, Xiaoguang; Lee, Ja Hyun; Yoo, Hah Young; Shin, Hyun Yong; Thapa, Laxmi Prasad; Park, Chulhwan; Kim, Seung Wook

    2014-08-01

    Instant noodle manufacturing waste was used as feedstock to convert it into two products, bioethanol and biodiesel. The raw material was pretreated to separate it into two potential feedstocks, starch residues and palm oil, for conversion to bioethanol and biodiesel, respectively. For the production of bioethanol, starch residues were converted into glucose by α-amylase and glucoamylase. To investigate the saccharification process of the pretreated starch residues, the optimal pretreatment conditions were determined. The bioethanol conversion reached 98.5 % of the theoretical maximum by Saccharomyces cerevisiae K35 fermentation after saccharification under optimized pretreatment conditions. Moreover, palm oil, isolated from the instant noodle waste, was converted into valuable biodiesel by use of immobilized lipase (Novozym 435). The effects of four categories of alcohol, oil-to-methanol ratio, reaction time, lipase concentration and water content on the conversion process were investigated. The maximum biodiesel conversion was 95.4 %.

  2. Sound of a cup with and without instant coffee

    NASA Astrophysics Data System (ADS)

    Morrison, Andrew; Rossing, Thomas D.

    2002-05-01

    An empty coffee cup, like an ancient Chinese two-tone bell, emits two distinctly different tones, depending upon where it is tapped. When it is filled with hot water, and some instant coffee is added, however, a whole new set of sounds is heard when the cup is tapped. The pitch rises an octave or more as the foam clears due to the dramatic change in the speed of sound in the bubble-filled liquid. A similar, but smaller, effect was noted in beer by Bragg [The World of Sound (1968)] and in hot chocolate by Crawford [Am. J. Phys. (1982)]. We describe the modes of vibration in a coffee cup and the sound emitted by a coffee cup as filled with instant coffee as the bubble density changes.

  3. Lunar Surface Closeup Stereoscopic Photography on the Ocean of Storms (Apollo 12 Landing Site)

    NASA Technical Reports Server (NTRS)

    Heiken, G.; Carrier, W. D., III

    1971-01-01

    To obtain information about in-place lunar rocks and soil, a closeup stereoscopic camera capable of photographing small scale surface features was used at the Apollo 12 landing site on the Ocean of Storms. Fifteen stereoscopic photograph pairs were obtained. The stereoscopic pairs were of excellent quality and showed the in-place lunar material in detail. The photographs were analyzed and the results compared with the results of the Apollo 12 core sample analysis and other investigations. Significant information about the physical composition and genesis of the lunar soil at the Apollo 12 landing site was obtained. The cohesive soil on the Ocean of Storms probably results from repetitive bombardment of basalt flows by meteorites over long periods of time.

  4. Stereoscopic three-dimensional television using active glasses with switchable refraction

    NASA Astrophysics Data System (ADS)

    Shestak, Sergey; Kim, Dae-Sik; Cha, Kyung-Hoon

    2015-05-01

    We have devised a full-resolution stereoscopic television system incorporating both a patterned retarder and active glasses. Selective vision of the left image by the left eye and the right image by the right eye is achieved by a conventional combination of a patterned retarder and left and right polarized filters. Full resolution is provided by the active components of the glasses acting as a switchable refractive-type beam displacer. Pairs of line-interleaved images are displayed on an LCD screen sequentially at a frame rate of 120 Hz. With the help of active refraction glasses, the viewer can see full-resolution stereoscopic images as if they are displayed in an interlaced manner. Active glasses are flicker-free. Measured stereoscopic crosstalk is 0.6%, which is defined only by the performance of the patterned retarder.

  5. Comparison of form in potential functions while maintaining upright posture during exposure to stereoscopic video clips.

    PubMed

    Kutsuna, Kenichiro; Matsuura, Yasuyuki; Fujikake, Kazuhiro; Miyao, Masaru; Takada, Hiroki

    2013-01-01

    Visually induced motion sickness (VIMS) is caused by sensory conflict, the disagreement between vergence and visual accommodation while observing stereoscopic images. VIMS can be measured by psychological and physiological methods. We propose a mathematical methodology to measure the effect of three-dimensional (3D) images on the equilibrium function. In this study, body sway in the resting state is compared with that during exposure to 3D video clips on a liquid crystal display (LCD) and on a head mounted display (HMD). In addition, the Simulator Sickness Questionnaire (SSQ) was completed immediately afterward. Based on the statistical analysis of the SSQ subscores and each index for stabilograms, we succeeded in determining the quantity of the VIMS during exposure to the stereoscopic images. Moreover, we discuss the metamorphism in the potential functions to control the standing posture during the exposure to stereoscopic video clips.

  6. Assessment of visual-spatial skills in medical context tasks when using monoscopic and stereoscopic visualization

    NASA Astrophysics Data System (ADS)

    Martinez Escobar, Marisol; Juhnke, Bethany; Hisley, Kenneth; Eliot, David; Winer, Eliot

    2013-03-01

    The dramatic rise of digital medical imaging has allowed medical personnel to see inside their patients as never before. Many software products are now available to view this data in various 2D and 3D formats. This also raises many basic research questions on spatial perception for humans viewing these images. The work presented here attempts to answer the question: How would adding the stereopsis depth cue affect relative position tasks in a medical context? By designing and conducting a study to isolate the benefits between monoscopic 3D and stereoscopic 3D displays in a relative position task, the following hypothesis was tested: stereoscopic 3D displays are beneficial over monoscopic 3D displays for relative position judgment tasks in a medical visualization setting. The results show that stereoscopic condition yielded a higher score than the monoscopic condition, but the results were not always statistically significant.

  7. High-speed switchable lens enables the development of a volumetric stereoscopic display

    PubMed Central

    Love, Gordon D.; Hoffman, David M.; Hands, Philip J.W.; Gao, James; Kirby, Andrew K.; Banks, Martin S.

    2011-01-01

    Stereoscopic displays present different images to the two eyes and thereby create a compelling three-dimensional (3D) sensation. They are being developed for numerous applications including cinema, television, virtual prototyping, and medical imaging. However, stereoscopic displays cause perceptual distortions, performance decrements, and visual fatigue. These problems occur because some of the presented depth cues (i.e., perspective and binocular disparity) specify the intended 3D scene while focus cues (blur and accommodation) specify the fixed distance of the display itself. We have developed a stereoscopic display that circumvents these problems. It consists of a fast switchable lens synchronized to the display such that focus cues are nearly correct. The system has great potential for both basic vision research and display applications. PMID:19724571

  8. Comparison of form in potential functions while maintaining upright posture during exposure to stereoscopic video clips.

    PubMed

    Kutsuna, Kenichiro; Matsuura, Yasuyuki; Fujikake, Kazuhiro; Miyao, Masaru; Takada, Hiroki

    2013-01-01

    Visually induced motion sickness (VIMS) is caused by sensory conflict, the disagreement between vergence and visual accommodation while observing stereoscopic images. VIMS can be measured by psychological and physiological methods. We propose a mathematical methodology to measure the effect of three-dimensional (3D) images on the equilibrium function. In this study, body sway in the resting state is compared with that during exposure to 3D video clips on a liquid crystal display (LCD) and on a head mounted display (HMD). In addition, the Simulator Sickness Questionnaire (SSQ) was completed immediately afterward. Based on the statistical analysis of the SSQ subscores and each index for stabilograms, we succeeded in determining the quantity of the VIMS during exposure to the stereoscopic images. Moreover, we discuss the metamorphism in the potential functions to control the standing posture during the exposure to stereoscopic video clips. PMID:24111406

  9. High-speed switchable lens enables the development of a volumetric stereoscopic display.

    PubMed

    Love, Gordon D; Hoffman, David M; Hands, Philip J W; Gao, James; Kirby, Andrew K; Banks, Martin S

    2009-08-31

    Stereoscopic displays present different images to the two eyes and thereby create a compelling three-dimensional (3D) sensation. They are being developed for numerous applications including cinema, television, virtual prototyping, and medical imaging. However, stereoscopic displays cause perceptual distortions, performance decrements, and visual fatigue. These problems occur because some of the presented depth cues (i.e., perspective and binocular disparity) specify the intended 3D scene while focus cues (blur and accommodation) specify the fixed distance of the display itself. We have developed a stereoscopic display that circumvents these problems. It consists of a fast switchable lens synchronized to the display such that focus cues are nearly correct. The system has great potential for both basic vision research and display applications.

  10. Managing the Risks and Rewards of Instant Messaging

    ERIC Educational Resources Information Center

    Goldsborough, Reid

    2004-01-01

    You probably think instant messaging (IM) as something teenagers do to chat up friends online, whether across the street or across the world. But IM has some buttoned-down business benefits, as well as some risks you may not be aware of. Unlike e-mail, in which you fire off messages to recipients who read them when they next check their in-box,…

  11. Genotoxicity of instant coffee: possible involvement of phenolic compounds.

    PubMed

    Duarte, M P; Laires, A; Gaspar, J; Leão, D; Oliveira, J S; Rueff, J

    1999-06-01

    Instant coffee exhibits direct genotoxic activity in the tester strains TA 98, 100, 102, 104 and YG 1024. In the Ames tester strain TA 100, the presence of S9 mix, S100 mix, S9 mix without cofactors led to a significant decrease of the genotoxicity observed. The decrease observed in the presence of S9 mix seems to be highly correlated with the catalase content of S9 mix. The genotoxicity of instant coffee detected in strain TA 100 was dependent on the pH, with higher genotoxic effects at pH values above neutrality. Also, dependent on the pH was the ability of some phenolic molecules present in coffee promoting the degradation of deoxyribose in the presence of Fe3+/EDTA. These results suggest that apart from other molecules present in instant coffee responsible for their genotoxicity in several short term assays, phenolic molecules could also be implicated in the genotoxicity of coffee, via reactive oxygen species arising from its auto-oxidation.

  12. Emulsifiers and thickeners on extrusion-cooked instant rice product.

    PubMed

    Wang, Jin Peng; An, Hong Zhou; Jin, Zheng Yu; Xie, Zheng Jun; Zhuang, Hai Ning; Kim, Jin Moon

    2013-08-01

    Extrusion-cooked instant rice was prepared by optimizing the formulation with emulsifiers, glycerol monostearate (GMS), soybean lecithin (LC), and sodiumstearoyl lactylate (SSL), and thickeners, gum Arabic (GA), sodium alginate (SA), and sticky rice (SR). The emulsifiers addition caused increase of degree of gelatinization (DG), and decrease of water soluble carbohydrate (WSC), α-amylase sensitivity, water soluble index (WAI) and adhesive for extrudates, while the thickeners addition increased extrudates DG, bulk density (BD), WSC, α-amylase sensitivity, WAI, hydration rate (HR) and adhesiveness. Based on the data generated by a single additive at various levels, optimum formulation was obtained employing orthogonal matrix system with combination of the selected additives for extrusion cooking. Extrudates were evaluated for optimum hydration time followed by drying to prepare the finished product. Texture profile analysis and sensory evaluation indicate that quality of the finished product is equivalent to that of the round shaped rice and superior to a commercial instant rice product. This study also demonstrates possibility of value-added and versatile instant rice product development using broken rice. PMID:24425967

  13. [Effects of stereoscopic cultivation on soil microorganism, enzyme activity and the agronomic characters of Panax notoginseng].

    PubMed

    Liao, Pei-ran; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Compartments of soil microorganism and enzymes between stereoscopic cultivation (three storeys) and field cultivation (CK) of Panax notoginseng were carried out, and the effects on P. notoginseng agronomic characters were also studied. Results show that concentration of soil microorganism of stereoscopic cultivation was lower than field cultivation; the activity of soil urea enzyme, saccharase and neutral phosphatase increased from lower storey to upper storey; the activity of soil urea enzyme and saccharase of lower and upper storeys were significantly lower than CK; agronomic characters of stereoscopic cultivated P. notoginsengin were inferior to field cultivation, the middle storey with the best agronomic characters among the three storeys. The correlation analysis showed that fungi, actinomycetes and neutral phosphatase were significantly correlated with P. notoginseng agronomic characters; concentration of soil fungi and bacteria were significantly correlated with the soil relative water content; actinomycete and neutral phosphatase were significantly correlated with soil pH and relative water content, respectively; the activities of soil urea enzyme and saccharase were significantly correlated with the soil daily maximum temperature difference. Inconclusion, The current research shows that the imbalance of soil microorganism and the acutely changing of soil enzyme activity were the main reasons that caused the agronomic characters of stereoscopic cultivated P. notoginseng were worse than field cultivation. Thus improves the concentration of soil microorganism and enzyme activity near to field soil by improving the structure of stereoscopic cultivation is very important. And it was the direction which we are endeavoring that built better soil ecological environment for P. notoginseng of stereoscopic cultivation.

  14. [Effects of stereoscopic cultivation on soil microorganism, enzyme activity and the agronomic characters of Panax notoginseng].

    PubMed

    Liao, Pei-ran; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Compartments of soil microorganism and enzymes between stereoscopic cultivation (three storeys) and field cultivation (CK) of Panax notoginseng were carried out, and the effects on P. notoginseng agronomic characters were also studied. Results show that concentration of soil microorganism of stereoscopic cultivation was lower than field cultivation; the activity of soil urea enzyme, saccharase and neutral phosphatase increased from lower storey to upper storey; the activity of soil urea enzyme and saccharase of lower and upper storeys were significantly lower than CK; agronomic characters of stereoscopic cultivated P. notoginsengin were inferior to field cultivation, the middle storey with the best agronomic characters among the three storeys. The correlation analysis showed that fungi, actinomycetes and neutral phosphatase were significantly correlated with P. notoginseng agronomic characters; concentration of soil fungi and bacteria were significantly correlated with the soil relative water content; actinomycete and neutral phosphatase were significantly correlated with soil pH and relative water content, respectively; the activities of soil urea enzyme and saccharase were significantly correlated with the soil daily maximum temperature difference. Inconclusion, The current research shows that the imbalance of soil microorganism and the acutely changing of soil enzyme activity were the main reasons that caused the agronomic characters of stereoscopic cultivated P. notoginseng were worse than field cultivation. Thus improves the concentration of soil microorganism and enzyme activity near to field soil by improving the structure of stereoscopic cultivation is very important. And it was the direction which we are endeavoring that built better soil ecological environment for P. notoginseng of stereoscopic cultivation. PMID:26677687

  15. Stereoscopic three-dimensional visualization applied to multimodal brain images: clinical applications and a functional connectivity atlas

    PubMed Central

    Rojas, Gonzalo M.; Gálvez, Marcelo; Vega Potler, Natan; Craddock, R. Cameron; Margulies, Daniel S.; Castellanos, F. Xavier; Milham, Michael P.

    2014-01-01

    Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity. PMID:25414626

  16. Stereoscopic three-dimensional visualization applied to multimodal brain images: clinical applications and a functional connectivity atlas.

    PubMed

    Rojas, Gonzalo M; Gálvez, Marcelo; Vega Potler, Natan; Craddock, R Cameron; Margulies, Daniel S; Castellanos, F Xavier; Milham, Michael P

    2014-01-01

    Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

  17. Computed Tomography

    NASA Astrophysics Data System (ADS)

    Castellano, Isabel; Geleijns, Jacob

    After its clinical introduction in 1973, computed tomography developed from an x-ray modality for axial imaging in neuroradiology into a versatile three dimensional imaging modality for a wide range of applications in for example oncology, vascular radiology, cardiology, traumatology and even in interventional radiology. Computed tomography is applied for diagnosis, follow-up studies and screening of healthy subpopulations with specific risk factors. This chapter provides a general introduction in computed tomography, covering a short history of computed tomography, technology, image quality, dosimetry, room shielding, quality control and quality criteria.

  18. Visual storytelling in 2D and stereoscopic 3D video: effect of blur on visual attention

    NASA Astrophysics Data System (ADS)

    Huynh-Thu, Quan; Vienne, Cyril; Blondé, Laurent

    2013-03-01

    Visual attention is an inherent mechanism that plays an important role in the human visual perception. As our visual system has limited capacity and cannot efficiently process the information from the entire visual field, we focus our attention on specific areas of interest in the image for detailed analysis of these areas. In the context of media entertainment, the viewers' visual attention deployment is also influenced by the art of visual storytelling. To this date, visual editing and composition of scenes in stereoscopic 3D content creation still mostly follows those used in 2D. In particular, out-of-focus blur is often used in 2D motion pictures and photography to drive the viewer's attention towards a sharp area of the image. In this paper, we study specifically the impact of defocused foreground objects on visual attention deployment in stereoscopic 3D content. For that purpose, we conducted a subjective experiment using an eyetracker. Our results bring more insights on the deployment of visual attention in stereoscopic 3D content viewing, and provide further understanding on visual attention behavior differences between 2D and 3D. Our results show that a traditional 2D scene compositing approach such as the use of foreground blur does not necessarily produce the same effect on visual attention deployment in 2D and 3D. Implications for stereoscopic content creation and visual fatigue are discussed.

  19. Human factors issues in the design of stereo-rendered photorealistic objects: a stereoscopic Turing test

    NASA Astrophysics Data System (ADS)

    Brack, Collin D.; Clewlow, John C.; Kessel, Ivan

    2010-02-01

    We present visual acuity metrics, human factors issues, and technical considerations in the construction of a stereorendered reality test in the spirit of the Turing test, Alan Turing's famous artificial intelligence test designed to explore the boundaries between human and machine interaction. The overall aim of this work is to provide guiding principles in the design of a stereoscopic reality test.

  20. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  1. M pathway and areas 44 and 45 are involved in stereoscopic recognition based on binocular disparity.

    PubMed

    Negawa, Tsuneo; Mizuno, Shinji; Hahashi, Tomoya; Kuwata, Hiromi; Tomida, Mihoko; Hoshi, Hiroaki; Era, Seiichi; Kuwata, Kazuo

    2002-04-01

    We characterized the visual pathways involved in the stereoscopic recognition of the random dot stereogram based on the binocular disparity employing a functional magnetic resonance imaging (fMRI). The V2, V3, V4, V5, intraparietal sulcus (IPS) and the superior temporal sulcus (STS) were significantly activated during the binocular stereopsis, but the inferotemporal gyrus (ITG) was not activated. Thus a human M pathway may be part of a network involved in the stereoscopic processing based on the binocular disparity. It is intriguing that areas 44 (Broca's area) and 45 in the left hemisphere were also active during the binocular stereopsis. However, it was reported that these regions were inactive during the monocular stereopsis. To separate the specific responses directly caused by the stereoscopic recognition process from the nonspecific ones caused by the memory load or the intention, we designed a novel frequency labeled tasks (FLT) sequence. The functional MRI using the FLT indicated that the activation of areas 44 and 45 is correlated with the stereoscopic recognition based on the binocular disparity but not with the intention artifacts, suggesting that areas 44 and 45 play an essential role in the binocular disparity. PMID:12139777

  2. Use of camera drive in stereoscopic display of learning contents of introductory physics

    NASA Astrophysics Data System (ADS)

    Matsuura, Shu

    2011-03-01

    Simple 3D physics simulations with stereoscopic display were created for a part of introductory physics e-Learning. First, cameras to see the 3D world can be made controllable by the user. This enabled to observe the system and motions of objects from any position in the 3D world. Second, cameras were made attachable to one of the moving object in the simulation so as to observe the relative motion of other objects. By this option, it was found that users perceive the velocity and acceleration more sensibly on stereoscopic display than on non-stereoscopic 3D display. Simulations were made using Adobe Flash ActionScript, and Papervison 3D library was used to render the 3D models in the flash web pages. To display the stereogram, two viewports from virtual cameras were displayed in parallel in the same web page. For observation of stereogram, the images of two viewports were superimposed by using 3D stereogram projection box (T&TS CO., LTD.), and projected on an 80-inch screen. The virtual cameras were controlled by keyboard and also by Nintendo Wii remote controller buttons. In conclusion, stereoscopic display offers learners more opportunities to play with the simulated models, and to perceive the characteristics of motion better.

  3. What is 3D good for? A review of human performance on stereoscopic 3D displays

    NASA Astrophysics Data System (ADS)

    McIntire, John P.; Havig, Paul R.; Geiselman, Eric E.

    2012-06-01

    This work reviews the human factors-related literature on the task performance implications of stereoscopic 3D displays, in order to point out the specific performance benefits (or lack thereof) one might reasonably expect to observe when utilizing these displays. What exactly is 3D good for? Relative to traditional 2D displays, stereoscopic displays have been shown to enhance performance on a variety of depth-related tasks. These tasks include judging absolute and relative distances, finding and identifying objects (by breaking camouflage and eliciting perceptual "pop-out"), performing spatial manipulations of objects (object positioning, orienting, and tracking), and navigating. More cognitively, stereoscopic displays can improve the spatial understanding of 3D scenes or objects, improve memory/recall of scenes or objects, and improve learning of spatial relationships and environments. However, for tasks that are relatively simple, that do not strictly require depth information for good performance, where other strong cues to depth can be utilized, or for depth tasks that lie outside the effective viewing volume of the display, the purported performance benefits of 3D may be small or altogether absent. Stereoscopic 3D displays come with a host of unique human factors problems including the simulator-sickness-type symptoms of eyestrain, headache, fatigue, disorientation, nausea, and malaise, which appear to effect large numbers of viewers (perhaps as many as 25% to 50% of the general population). Thus, 3D technology should be wielded delicately and applied carefully; and perhaps used only as is necessary to ensure good performance.

  4. Stereoscopic imaging: filling disoccluded areas in depth image-based rendering

    NASA Astrophysics Data System (ADS)

    Vázquez, Carlos; Tam, Wa James; Speranza, Filippo

    2006-10-01

    Depth image based rendering (DIBR) is a method for converting 2D material to stereoscopic 3D. With DIBR, information contained in a gray-level (luminance intensity) depth map is used to shift pixels in the 2D image to generate a new image as if it were captured from a new viewpoint. The larger the shift (binocular parallax), the larger is the perceived depth of the generated stereoscopic pair. However, a major problem with DIBR is that the shifted pixels now occupy new positions and leave areas that they originally occupied "empty." These disoccluded regions have to be filled properly, otherwise they can degrade image quality. In this study we investigated different methods for filling these disoccluded regions: (a) Filling regions with a constant color, (b) filling regions with horizontal linear interpolation of values on the hole border, (c) solving the Laplace equation on the hole boundary and propagate the values inside the region, (d) horizontal extrapolation with depth information taken into account, (e) variational inpainting with depth information taken into account, and (f) preprocessing of the depth map to prevent disoccluded regions from appearing. The methods differed in the time required for computing and filling, and the appearance of the filled-in regions. We assessed the subjective image quality outcome for several stereoscopic test images in which the left-eye view was the source and the right-eye view was a rendered view, in line with suggestions in the literature for the asymmetrical coding of stereoscopic images.

  5. Stereoscopic 3D display with dynamic optical correction for recovering from asthenopia

    NASA Astrophysics Data System (ADS)

    Shibata, Takashi; Kawai, Takashi; Otsuki, Masaki; Miyake, Nobuyuki; Yoshihara, Yoshihiro; Iwasaki, Tsuneto

    2005-03-01

    The purpose of this study was to consider a practical application of a newly developed stereoscopic 3-D display that solves the problem of discrepancy between accommodation and convergence. The display uses dynamic optical correction to reduce the discrepancy, and can present images as if they are actually remote objects. The authors thought the display may assist in recovery from asthenopia, which is often caused when the eyes focus on a nearby object for a long time, such as in VDT (Visual Display Terminal) work. In general, recovery from asthenopia, and especially accommodative asthenopia, is achieved by focusing on distant objects. In order to verify this hypothesis, the authors performed visual acuity tests using Landolt rings before and after presenting stereoscopic 3-D images, and evaluated the degree of recovery from asthenopia. The experiment led to three main conclusions: (1) Visual acuity rose after viewing stereoscopic 3-D images on the developed display. (2) Recovery from asthenopia was particularly effective for the dominant eye in comparison with the other eye. (3) Interviews with the subjects indicated that the Landolt rings were particularly clear after viewing the stereoscopic 3-D images.

  6. Examination of asthenopia recovery using stereoscopic 3D display with dynamic optical correction

    NASA Astrophysics Data System (ADS)

    Shibata, Takashi; Kawai, Takashi; Ohta, Keiji; Lee, JaeLin; Otsuki, Masaki; Miyake, Nobuyuki; Yoshihara, Yoshihiro; Iwasaki, Tsuneto

    2006-02-01

    A common cause of asthenopia is viewing objects from a short distance, as is the case when working at a VDT (Visual Display Terminal). In general, recovery from asthenopia, especially accommodative asthenopia, is aided by looking into the distance. The authors have developed a stereoscopic 3-D display with dynamic optical correction that may reduce asthenopia. The display does this by reducing the discrepancy between accommodation and convergence, thereby presenting images as if they were actually in the distance. The results of visual acuity tests given before and after presenting stereoscopic 3-D images with this display show a tendency towards less asthenopia. In this study, the authors developed a refraction feedback function that makes the viewer's distance vision more effective when viewing stereoscopic 3-D images on the this display. Using this function, refraction is fed back during viewing and the viewer gradually acquires distance vision. The results of the study suggest that stereoscopic 3-D images are more effective than 2-D images for recovery from asthenopia.

  7. Stereoscopic video analysis of Anopheles gambiae behavior in the field: challenges and opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advances in our ability to localize and track individual swarming mosquitoes in the field via stereoscopic image analysis have enabled us to test long standing ideas about individual male behavior and directly observe coupling. These studies further our fundamental understanding of the reproductive ...

  8. Subjective experiences of watching stereoscopic Avatar and U2 3D in a cinema

    NASA Astrophysics Data System (ADS)

    Pölönen, Monika; Salmimaa, Marja; Takatalo, Jari; Häkkinen, Jukka

    2012-01-01

    A stereoscopic 3-D version of the film Avatar was shown to 85 people who subsequently answered questions related to sickness, visual strain, stereoscopic image quality, and sense of presence. Viewing Avatar for 165 min induced some symptoms of visual strain and sickness, but the symptom levels remained low. A comparison between Avatar and previously published results for the film U2 3D showed that sickness and visual strain levels were similar despite the films' runtimes. The genre of the film had a significant effect on the viewers' opinions and sense of presence. Avatar, which has been described as a combination of action, adventure, and sci-fi genres, was experienced as more immersive and engaging than the music documentary U2 3D. However, participants in both studies were immersed, focused, and absorbed in watching the stereoscopic 3-D (S3-D) film and were pleased with the film environments. The results also showed that previous stereoscopic 3-D experience significantly reduced the amount of reported eye strain and complaints about the weight of the viewing glasses.

  9. Organizational Learning Goes Virtual?: A Study of Employees' Learning Achievement in Stereoscopic 3D Virtual Reality

    ERIC Educational Resources Information Center

    Lau, Kung Wong

    2015-01-01

    Purpose: This study aims to deepen understanding of the use of stereoscopic 3D technology (stereo3D) in facilitating organizational learning. The emergence of advanced virtual technologies, in particular to the stereo3D virtual reality, has fundamentally changed the ways in which organizations train their employees. However, in academic or…

  10. M pathway and areas 44 and 45 are involved in stereoscopic recognition based on binocular disparity.

    PubMed

    Negawa, Tsuneo; Mizuno, Shinji; Hahashi, Tomoya; Kuwata, Hiromi; Tomida, Mihoko; Hoshi, Hiroaki; Era, Seiichi; Kuwata, Kazuo

    2002-04-01

    We characterized the visual pathways involved in the stereoscopic recognition of the random dot stereogram based on the binocular disparity employing a functional magnetic resonance imaging (fMRI). The V2, V3, V4, V5, intraparietal sulcus (IPS) and the superior temporal sulcus (STS) were significantly activated during the binocular stereopsis, but the inferotemporal gyrus (ITG) was not activated. Thus a human M pathway may be part of a network involved in the stereoscopic processing based on the binocular disparity. It is intriguing that areas 44 (Broca's area) and 45 in the left hemisphere were also active during the binocular stereopsis. However, it was reported that these regions were inactive during the monocular stereopsis. To separate the specific responses directly caused by the stereoscopic recognition process from the nonspecific ones caused by the memory load or the intention, we designed a novel frequency labeled tasks (FLT) sequence. The functional MRI using the FLT indicated that the activation of areas 44 and 45 is correlated with the stereoscopic recognition based on the binocular disparity but not with the intention artifacts, suggesting that areas 44 and 45 play an essential role in the binocular disparity.

  11. Fusion Prevents the Redundant Signals Effect: Evidence from Stereoscopically Presented Stimuli

    ERIC Educational Resources Information Center

    Schroter, Hannes; Fiedler, Anja; Miller, Jeff; Ulrich, Rolf

    2011-01-01

    In a simple reaction time (RT) experiment, visual stimuli were stereoscopically presented either to one eye (single stimulation) or to both eyes (redundant stimulation), with brightness matched for single and redundant stimulations. Redundant stimulation resulted in two separate percepts when noncorresponding retinal areas were stimulated, whereas…

  12. Disparity profiles in 3DV applications: overcoming the issue of heterogeneous viewing conditions in stereoscopic delivery

    NASA Astrophysics Data System (ADS)

    Boisson, Guillaume; Chamaret, Christel

    2012-03-01

    More and more numerous 3D movies are released each year. Thanks to the current spread of 3D-TV displays, these 3D Video (3DV) contents are about to enter massively the homes. Yet viewing conditions determine the stereoscopic features achievable for 3DV material. Because the conditions at home - screen size and distance to screen - differ significantly from a theater, 3D Cinema movies need to be repurposed before broadcast and replication on 3D Blu-ray Discs for being fully enjoyed at home. In that paper we tackle that particular issue of how to handle the variety of viewing conditions in stereoscopic contents delivery. To that extend we first investigate what is basically at stake for granting stereoscopic viewers' comfort, through the well-known - and sometimes dispraised - vergence-accommodation conflict. Thereby we define a set of basic rules that can serve as guidelines for 3DV creation. We propose disparity profiles as new requirements for 3DV production and repurposing. Meeting proposed background and foreground constraints prevents from visual fatigue, and occupying the whole depth budget available grants optimal 3D effects. We present an efficient algorithm for automatic disparity-based 3DV retargeting depending on the viewing conditions. Variants are proposed depending on the input format (stereoscopic binocular content or depth-based format) and the level of complexity achievable.

  13. Accurate analysis of blood vessel sizes and stenotic lesions using stereoscopic DSA system.

    PubMed

    Fencil, L E; Doi, K; Hoffman, K R

    1988-01-01

    We have developed a technique to determine accurately the magnification factor and three-dimensional orientation of a vessel segment from a stereoscopic pair of digital subtraction angiograms (DSA). Our DSA system includes a stereoscopic x-ray tube with a 25-mm focal spot shift. The magnification and orientation of a selected vessel segment are determined from the distance and direction of the focal spot shift and the stereoscopic discrepancy in image positions for that segment. Our results indicate that the accuracies of determining the magnification and orientation are less than 1% and approximately 5 degrees, respectively. After the magnification and orientation are determined accurately, an iterative deconvolution technique for the measurement of vessel image size is applied to the selected vessel segment. This iterative deconvolution technique provides the best estimate of vessel image size by taking into account the unsharpness of the digital system. With this technique, the vessel image size can be determined to an accuracy of approximately 1.0 mm, which corresponds to one third the pixel size of our DSA system. Information derived from stereoscopic analysis and iterative deconvolution thus allows accurate calculation of actual vascular dimensions from DSA images.

  14. Guidance for horizontal image translation (HIT) of high definition stereoscopic video production

    NASA Astrophysics Data System (ADS)

    Broberg, David K.

    2011-03-01

    Horizontal image translation (HIT) is an electronic process for shifting the left-eye and right-eye images horizontally as a way to alter the stereoscopic characteristics and alignment of 3D content after signals have been captured by stereoscopic cameras. When used cautiously and with full awareness of the impact on other interrelated aspects of the stereography, HIT is a valuable tool in the post production process as a means to modify stereoscopic content for more comfortable viewing. Most commonly it is used to alter the zero parallax setting (ZPS), to compensate for stereo window violations or to compensate for excessive positive or negative parallax in the source material. As more and more cinematic 3D content migrates to television distribution channels the use of this tool will likely expand. Without proper attention to certain guidelines the use of HIT can actually harm the 3D viewing experience. This paper provides guidance on the most effective use and describes some of the interrelationships and trade-offs. The paper recommends the adoption of the cinematic 2K video format as a 3D source master format for high definition television distribution of stereoscopic 3D video programming.

  15. Evaluation of stereoscopic medical video content on an autostereoscopic display for undergraduate medical education

    NASA Astrophysics Data System (ADS)

    Ilgner, Justus F. R.; Kawai, Takashi; Shibata, Takashi; Yamazoe, Takashi; Westhofen, Martin

    2006-02-01

    Introduction: An increasing number of surgical procedures are performed in a microsurgical and minimally-invasive fashion. However, the performance of surgery, its possibilities and limitations become difficult to teach. Stereoscopic video has evolved from a complex production process and expensive hardware towards rapid editing of video streams with standard and HDTV resolution which can be displayed on portable equipment. This study evaluates the usefulness of stereoscopic video in teaching undergraduate medical students. Material and methods: From an earlier study we chose two clips each of three different microsurgical operations (tympanoplasty type III of the ear, endonasal operation of the paranasal sinuses and laser chordectomy for carcinoma of the larynx). This material was added by 23 clips of a cochlear implantation, which was specifically edited for a portable computer with an autostereoscopic display (PC-RD1-3D, SHARP Corp., Japan). The recording and synchronization of left and right image was performed at the University Hospital Aachen. The footage was edited stereoscopically at the Waseda University by means of our original software for non-linear editing of stereoscopic 3-D movies. Then the material was converted into the streaming 3-D video format. The purpose of the conversion was to present the video clips by a file type that does not depend on a television signal such as PAL or NTSC. 25 4th year medical students who participated in the general ENT course at Aachen University Hospital were asked to estimate depth clues within the six video clips plus cochlear implantation clips. Another 25 4th year students who were shown the material monoscopically on a conventional laptop served as control. Results: All participants noted that the additional depth information helped with understanding the relation of anatomical structures, even though none had hands-on experience with Ear, Nose and Throat operations before or during the course. The monoscopic

  16. Development of an instant coffee enriched with chlorogenic acids.

    PubMed

    Corso, Marinês Paula; Vignoli, Josiane Alessandra; Benassi, Marta de Toledo

    2016-03-01

    The objective of this study was to present possible formulations for an instant coffee product enriched with chlorogenic acids for the Brazilian market. Formulations were prepared with different concentrations of freeze dried extracts of green Coffea canephora beans (G) added to freeze dried extracts of roasted Coffea arabica (A) and Coffea canephora (C). Medium (M) and dark (D) roasting degrees instant coffee were produced (AM, AD, CM and CD) to obtain four formulations with green extract addition (AMG, ADG, CMG and CDG). Chlorogenic acids were determined by HPLC, with average contents of 7.2 %. Roasted extracts and formulations were evaluated for 5-CQA and caffeine contents (by HPLC), browned compounds (absorbance 420 nm), and antioxidant activity (ABTS and Folin). Coffee brews of the four formulations were also assessed in a lab-scale test by 42 consumers for acceptance of the color, aroma, flavor and body, overall acceptance and purchase intent, using a 10 cm hybrid scale. The formulations obtained acceptance scores of 6.6 and 7.7 for all attributes, thus they were equally acceptable. Greater purchase intent was observed for ADG, CDG and CMG (6.9) in comparison to AMG (6.1). The formulations had, on average, 2.5 times more 5-CQA than the average obtained from conventional commercial instant coffees. In addition to being more economically viable, the formulations developed with C. canephora (CDG and CMG) showed greater antioxidant potential (32.5 g of Trolox/100 g and 13.8 g of gallic acid equivalent/100 g) due to a balance in the amount of bioactive compounds. PMID:27570262

  17. Development of an instant coffee enriched with chlorogenic acids.

    PubMed

    Corso, Marinês Paula; Vignoli, Josiane Alessandra; Benassi, Marta de Toledo

    2016-03-01

    The objective of this study was to present possible formulations for an instant coffee product enriched with chlorogenic acids for the Brazilian market. Formulations were prepared with different concentrations of freeze dried extracts of green Coffea canephora beans (G) added to freeze dried extracts of roasted Coffea arabica (A) and Coffea canephora (C). Medium (M) and dark (D) roasting degrees instant coffee were produced (AM, AD, CM and CD) to obtain four formulations with green extract addition (AMG, ADG, CMG and CDG). Chlorogenic acids were determined by HPLC, with average contents of 7.2 %. Roasted extracts and formulations were evaluated for 5-CQA and caffeine contents (by HPLC), browned compounds (absorbance 420 nm), and antioxidant activity (ABTS and Folin). Coffee brews of the four formulations were also assessed in a lab-scale test by 42 consumers for acceptance of the color, aroma, flavor and body, overall acceptance and purchase intent, using a 10 cm hybrid scale. The formulations obtained acceptance scores of 6.6 and 7.7 for all attributes, thus they were equally acceptable. Greater purchase intent was observed for ADG, CDG and CMG (6.9) in comparison to AMG (6.1). The formulations had, on average, 2.5 times more 5-CQA than the average obtained from conventional commercial instant coffees. In addition to being more economically viable, the formulations developed with C. canephora (CDG and CMG) showed greater antioxidant potential (32.5 g of Trolox/100 g and 13.8 g of gallic acid equivalent/100 g) due to a balance in the amount of bioactive compounds.

  18. Studies on the optimization and stability of instant wheat porridge (Dalia) mix.

    PubMed

    Ayub Khan, Mohammed; Dutt Semwal, Anil; Kumar Sharma, Gopal; Singh Bawa, Amarinder

    2014-06-01

    Instant wheat porridge (Dalia) mix based on precooked broken wheat, sugar, skim milk powder and flavouring agents was developed using response surface methodology and central composite rotatable design. Stability of instant wheat porridge (Dalia) mix packed in polypropylene (PP) and metallised polyester (MP) pouches was evaluated. Instant porridge (Dalia) mix remained stable for 9 and 12 m respectively in PP and MP pouches under ambient temperature (15-34 °C) conditions. Deterioration in instant porridge mix during storage was mainly caused by autoxidation of lipids, browning due to maillard reaction and development of off-flavour.

  19. Synchronicity, instant messaging, and performance among financial traders

    PubMed Central

    Saavedra, Serguei; Hagerty, Kathleen; Uzzi, Brian

    2011-01-01

    Successful animal systems often manage risk through synchronous behavior that spontaneously arises without leadership. In critical human systems facing risk, such as financial markets or military operations, our understanding of the benefits associated with synchronicity is nascent but promising. Building on previous work illuminating commonalities between ecological and human systems, we compare the activity patterns of individual financial traders with the simultaneous activity of other traders—an individual and spontaneous characteristic we call synchronous trading. Additionally, we examine the association of synchronous trading with individual performance and communication patterns. Analyzing empirical data on day traders’ second-to-second trading and instant messaging, we find that the higher the traders’ synchronous trading is, the less likely they are to lose money at the end of the day. We also find that the daily instant messaging patterns of traders are closely associated with their level of synchronous trading. This result suggests that synchronicity and vanguard technology may help traders cope with risky decisions in complex systems and may furnish unique prospects for achieving collective and individual goals. PMID:21402941

  20. [Study of microorganism sterilization by instant microwave and electromagnetic pulse].

    PubMed

    Lu, Zhiyuan; Shi, Pinpin; Zhu, Manzuo; Sun, Wenquan; Ding, Hua; Hou, Jianqiang

    2008-08-01

    The sterilization effects of constant electromagnetic wave and instant pulse on foods and traditional Chinese medical pills are introduced in this paper. From the velum's voltage variation caused by the outward electric filed,the dielectric properties of membranaceous ion and the pass rate of the membranaceous ion, we could analyze the biological heating effect and the biological non-heating effect. The sterilization effect of constant electromagnetic wave is based on the biological heating effect, while the instant electromagnetic pulse is based on the biological non-heating effect. With the applied electronic field, the voltage of membrane could increase, which results in the gates of K+ open, and the flowing out of K+. And the variation of the membranaceous voltage makes the gates of Ca2+ open. The Ca2+ of large consistency could come into the cell by the gradient of voltage. It could induce the death of the cells. The greater the variation of membranaceous voltage becomes, the higher will be the death rate of the cells. PMID:18788285

  1. InstantLabs® Salmonella species detection method: matrix extension.

    PubMed

    Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit; Hayman, Melinda; Montez, Sergio J

    2014-01-01

    The performance of InstantLabs® Salmonella Species Food Safety Kit to detect Salmonella in four food matrixes was validated against the International Organization for Standardization (ISO) reference method 6579:2002. The matrixes (raw ground beef, raw chicken breast, raw ground chicken, and lettuce) were inoculated with low levels of Salmonella (<1 CFU/test portion) to generate fractional positives (5-15) in 20 inoculated samples. These matrixes were co-inoculated with Escherichia coli O157:H7 at two to five times the level of Salmonella. Samples were validated using 375 g (meat) or 25 g (lettuce and poultry) test portions enriched in FASTGRO TM SE at 42±1 °C for 12 h and 10 h, respectively. All samples were confirmed using the ISO reference method, regardless of initial-screen result. The InstantLabs test method was shown to perform as well as or better than the reference method for the detection of Salmonella species in ground beef, chicken breast, ground chicken, and lettuce. Inclusivity and exclusivity testing revealed no false negatives among the 100 Salmonella serovars and no false positives among the 30 non-Salmonella species examined, respectively.

  2. SEISVIZ3D: Stereoscopic system for the representation of seismic data - Interpretation and Immersion

    NASA Astrophysics Data System (ADS)

    von Hartmann, Hartwig; Rilling, Stefan; Bogen, Manfred; Thomas, Rüdiger

    2015-04-01

    The seismic method is a valuable tool for getting 3D-images from the subsurface. Seismic data acquisition today is not only a topic for oil and gas exploration but is used also for geothermal exploration, inspections of nuclear waste sites and for scientific investigations. The system presented in this contribution may also have an impact on the visualization of 3D-data of other geophysical methods. 3D-seismic data can be displayed in different ways to give a spatial impression of the subsurface.They are a combination of individual vertical cuts, possibly linked to a cubical portion of the data volume, and the stereoscopic view of the seismic data. By these methods, the spatial perception for the structures and thus of the processes in the subsurface should be increased. Stereoscopic techniques are e. g. implemented in the CAVE and the WALL, both of which require a lot of space and high technical effort. The aim of the interpretation system shown here is stereoscopic visualization of seismic data at the workplace, i.e. at the personal workstation and monitor. The system was developed with following criteria in mind: • Fast rendering of large amounts of data so that a continuous view of the data when changing the viewing angle and the data section is possible, • defining areas in stereoscopic view to translate the spatial impression directly into an interpretation, • the development of an appropriate user interface, including head-tracking, for handling the increased degrees of freedom, • the possibility of collaboration, i.e. teamwork and idea exchange with the simultaneous viewing of a scene at remote locations. The possibilities offered by the use of a stereoscopic system do not replace a conventional interpretation workflow. Rather they have to be implemented into it as an additional step. The amplitude distribution of the seismic data is a challenge for the stereoscopic display because the opacity level and the scaling and selection of the data have to

  3. Mastcam-Z: Designing a Geologic, Stereoscopic, and Multispectral Pair of Zoom Cameras for the NASA Mars 2020 Rover

    NASA Astrophysics Data System (ADS)

    Bell, J. F.; Maki, J. N.; Mehall, G. L.; Ravine, M. A.; Caplinger, M. A.; Mastcam-Z Team

    2016-10-01

    Mastcam-Z is a stereoscopic, multispectral imaging investigation selected for flight on the Mars 2020 rover mission. In this presentation we review our science goals and requirements and describe our CDR-level design and operational plans.

  4. Designing stereoscopic information visualization for 3D-TV: What can we can learn from S3D gaming?

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Masuch, Maic

    2012-03-01

    This paper explores graphical design and spatial alignment of visual information and graphical elements into stereoscopically filmed content, e.g. captions, subtitles, and especially more complex elements in 3D-TV productions. The method used is a descriptive analysis of existing computer- and video games that have been adapted for stereoscopic display using semi-automatic rendering techniques (e.g. Nvidia 3D Vision) or games which have been specifically designed for stereoscopic vision. Digital games often feature compelling visual interfaces that combine high usability with creative visual design. We explore selected examples of game interfaces in stereoscopic vision regarding their stereoscopic characteristics, how they draw attention, how we judge effect and comfort and where the interfaces fail. As a result, we propose a list of five aspects which should be considered when designing stereoscopic visual information: explicit information, implicit information, spatial reference, drawing attention, and vertical alignment. We discuss possible consequences, opportunities and challenges for integrating visual information elements into 3D-TV content. This work shall further help to improve current editing systems and identifies a need for future editing systems for 3DTV, e.g., live editing and real-time alignment of visual information into 3D footage.

  5. Factors Affecting Use of Instant Messaging Software by Information Technology Professionals

    ERIC Educational Resources Information Center

    Pratt, Robert C.

    2010-01-01

    Instant messaging systems--a type of social networking technology that connects people who are physically separated but working together--have seen a dramatic rise in use in globally dispersed organizations, yet there is an absence of academic research in predictive factors of instant messaging adoption. This study examined the factors influencing…

  6. Influence of the startup instant of quench in a superconducting current limiter

    SciTech Connect

    Leveque, J.; Netter, D.; Rezzoug, A.; Caron, J.P.; Sargos, F.M.

    1996-09-01

    The influence of the startup instant of the quench in a superconducting current limiter is studied. The heat transfer equation is numerically solved, using finite difference method, and taking the effects of current sharing into account. The results show the importance of this instant on the dissipated power, the temperature-increase and on the efficiency of the current limitation.

  7. Optimizing visual comfort for stereoscopic 3D display based on color-plus-depth signals.

    PubMed

    Shao, Feng; Jiang, Qiuping; Fu, Randi; Yu, Mei; Jiang, Gangyi

    2016-05-30

    Visual comfort is a long-facing problem in stereoscopic 3D (S3D) display. In this paper, targeting to produce S3D content based on color-plus-depth signals, a general framework for depth mapping to optimize visual comfort for S3D display is proposed. The main motivation of this work is to remap the depth range of color-plus-depth signals to a new depth range that is suitable to comfortable S3D display. Towards this end, we first remap the depth range globally based on the adjusted zero disparity plane, and then present a two-stage global and local depth optimization solution to solve the visual comfort problem. The remapped depth map is used to generate the S3D output. We demonstrate the power of our approach on perceptually uncomfortable and comfortable stereoscopic images. PMID:27410090

  8. [Stereoscopic remote sensing used in monitoring Enteromorpha Prolifra disaster in Chinese Yellow Sea].

    PubMed

    Gu, Xing-Fa; Chen, Xing-Feng; Yin, Qiu; Li, Zheng-Qiang; Xu, Hua; Shao, Yun; Li, Zi-Wei

    2011-06-01

    In the summer 2008, Enteromorpha Prolifra broke out in Yellow Sea and East Sea on a large scale for the first time, and became a marine disaster. The authors constructed a stereoscopic monitoring system which monitored the disaster continuously, dynamically and in real time. The present paper introduced the construction of the stereoscopic monitoring system; through analyzing the spectral characteristics of Enteromorpha Prolifra and ocean water which were acquired in a field experiment, confirmed Enteromorpha Prolifra retrieval models based on multi-platform multi-sensor and multi-spectral remote sensing data, contrasted the different scale monitoring results, and analyzed the evolvement rules with time-series analysis. This system was applied to the Enteromorpha Prolifra emergency monitoring in the 29th Olympic sailing area. It was proved feasible and valuable for the Olympic safeguard. PMID:21847947

  9. Two Eyes, 3D Early Results: Stereoscopic vs 2D Representations of Highly Spatial Scientific Imagery

    NASA Astrophysics Data System (ADS)

    Price, Aaron

    2013-06-01

    "Two Eyes, 3D" is a 3-year NSF funded research project to study the educational impacts of using stereoscopic representations in informal settings. The first study conducted as part of the project tested children 5-12 on their ability to perceive spatial elements of slides of scientific objects shown to them in either stereoscopic or 2D format. Children were also tested for prior spatial ability. Early results suggest that stereoscopy does not have a major impact on perceiving spatial elements of an image, but it does have a more significant impact on how the children apply that knowledge when presented with a common sense situation. The project is run by the AAVSO and this study was conducted at the Boston Museum of Science.

  10. Stereoscopic 3D entertainment and its effect on viewing comfort: comparison of children and adults.

    PubMed

    Pölönen, Monika; Järvenpää, Toni; Bilcu, Beatrice

    2013-01-01

    Children's and adults' viewing comfort during stereoscopic three-dimensional film viewing and computer game playing was studied. Certain mild changes in visual function, heterophoria and near point of accommodation values, as well as eyestrain and visually induced motion sickness levels were found when single setups were compared. The viewing system had an influence on viewing comfort, in particular for eyestrain levels, but no clear difference between two- and three-dimensional systems was found. Additionally, certain mild changes in visual functions and visually induced motion sickness levels between adults and children were found. In general, all of the system-task combinations caused mild eyestrain and possible changes in visual functions, but these changes in magnitude were small. According to subjective opinions that further support these measurements, using a stereoscopic three-dimensional system for up to 2 h was acceptable for most of the users regardless of their age.

  11. Phase-only stereoscopic hologram calculation based on Gerchberg–Saxton iterative algorithm

    NASA Astrophysics Data System (ADS)

    Xia, Xinyi; Xia, Jun

    2016-09-01

    A phase-only computer-generated holography (CGH) calculation method for stereoscopic holography is proposed in this paper. The two-dimensional (2D) perspective projection views of the three-dimensional (3D) object are generated by the computer graphics rendering techniques. Based on these views, a phase-only hologram is calculated by using the Gerchberg–Saxton (GS) iterative algorithm. Comparing with the non-iterative algorithm in the conventional stereoscopic holography, the proposed method improves the holographic image quality, especially for the phase-only hologram encoded from the complex distribution. Both simulation and optical experiment results demonstrate that our proposed method can give higher quality reconstruction comparing with the traditional method. Project supported by the National Basic Research Program of China (Grant No. 2013CB328803) and the National High Technology Research and Development Program of China (Grant Nos. 2013AA013904 and 2015AA016301).

  12. Electrothermal MEMS parallel plate rotation for single-imager stereoscopic endoscopes.

    PubMed

    Jang, Kyung-Won; Yang, Sung-Pyo; Baek, Seung-Hwan; Lee, Min-Suk; Park, Hyeon-Cheol; Seo, Yeong-Hyeon; Kim, Min H; Jeong, Ki-Hun

    2016-05-01

    This work reports electrothermal MEMS parallel plate-rotation (PPR) for a single-imager based stereoscopic endoscope. A thin optical plate was directly connected to an electrothermal MEMS microactuator with bimorph structures of thin silicon and aluminum layers. The fabricated MEMS PPR device precisely rotates an transparent optical plate up to 37° prior to an endoscopic camera and creates the binocular disparities, comparable to those from binocular cameras with a baseline distance over 100 μm. The anaglyph 3D images and disparity maps were successfully achieved by extracting the local binocular disparities from two optical images captured at the relative positions. The physical volume of MEMS PPR is well fit in 3.4 mm x 3.3 mm x 1 mm. This method provides a new direction for compact stereoscopic 3D endoscopic imaging systems.

  13. Electrothermal MEMS parallel plate rotation for single-imager stereoscopic endoscopes.

    PubMed

    Jang, Kyung-Won; Yang, Sung-Pyo; Baek, Seung-Hwan; Lee, Min-Suk; Park, Hyeon-Cheol; Seo, Yeong-Hyeon; Kim, Min H; Jeong, Ki-Hun

    2016-05-01

    This work reports electrothermal MEMS parallel plate-rotation (PPR) for a single-imager based stereoscopic endoscope. A thin optical plate was directly connected to an electrothermal MEMS microactuator with bimorph structures of thin silicon and aluminum layers. The fabricated MEMS PPR device precisely rotates an transparent optical plate up to 37° prior to an endoscopic camera and creates the binocular disparities, comparable to those from binocular cameras with a baseline distance over 100 μm. The anaglyph 3D images and disparity maps were successfully achieved by extracting the local binocular disparities from two optical images captured at the relative positions. The physical volume of MEMS PPR is well fit in 3.4 mm x 3.3 mm x 1 mm. This method provides a new direction for compact stereoscopic 3D endoscopic imaging systems. PMID:27137580

  14. Development of single-channel stereoscopic video imaging modality for real-time retinal imaging

    NASA Astrophysics Data System (ADS)

    Radfar, Edalat; Park, Jihoon; Lee, Sangyeob; Ha, Myungjin; Yu, Sungkon; Jang, Seulki; Jung, Byungjo

    2016-03-01

    Stereoscopic retinal image can effectively help doctors. Most of stereo imaging surgical microscopes are based on dual optical channels and benefit from dual cameras in which left and right cameras capture corresponding left and right eye views. This study developed a single-channel stereoscopic retinal imaging modality based on a transparent rotating deflector (TRD). Two different viewing angles are generated by imaging through the TRD which is mounted on a motor synchronized with a camera and is placed in single optical channel. Because of the function of objective lens in the imaging modality which generate stereo-image from an object at its focal point, and according to eye structure, the optical set up of the imaging modality can compatible for retinal imaging when the cornea and eye lens are engaged in objective lens.

  15. Self-calibration performance in stereoscopic PIV acquired in a transonic wind tunnel

    NASA Astrophysics Data System (ADS)

    Beresh, Steven J.; Wagner, Justin L.; Smith, Barton L.

    2016-04-01

    Three stereoscopic PIV experiments have been examined to test the effectiveness of self-calibration under varied circumstances. Measurements taken in a streamwise plane yielded a robust self-calibration that returned common results regardless of the specific calibration procedure, but measurements in the crossplane exhibited substantial velocity bias errors whose nature was sensitive to the particulars of the self-calibration approach. Self-calibration is complicated by thick laser sheets and large stereoscopic camera angles and further exacerbated by small particle image diameters and high particle seeding density. Despite the different answers obtained by varied self-calibrations, each implementation locked onto an apparently valid solution with small residual disparity and converged adjustment of the calibration plane. Therefore, the convergence of self-calibration on a solution with small disparity is not sufficient to indicate negligible velocity error due to the stereo calibration.

  16. Phase-only stereoscopic hologram calculation based on Gerchberg-Saxton iterative algorithm

    NASA Astrophysics Data System (ADS)

    Xia, Xinyi; Xia, Jun

    2016-09-01

    A phase-only computer-generated holography (CGH) calculation method for stereoscopic holography is proposed in this paper. The two-dimensional (2D) perspective projection views of the three-dimensional (3D) object are generated by the computer graphics rendering techniques. Based on these views, a phase-only hologram is calculated by using the Gerchberg-Saxton (GS) iterative algorithm. Comparing with the non-iterative algorithm in the conventional stereoscopic holography, the proposed method improves the holographic image quality, especially for the phase-only hologram encoded from the complex distribution. Both simulation and optical experiment results demonstrate that our proposed method can give higher quality reconstruction comparing with the traditional method. Project supported by the National Basic Research Program of China (Grant No. 2013CB328803) and the National High Technology Research and Development Program of China (Grant Nos. 2013AA013904 and 2015AA016301).

  17. Interactive and Stereoscopic Hybrid 3D Viewer of Radar Data with Gesture Recognition

    NASA Astrophysics Data System (ADS)

    Goenetxea, Jon; Moreno, Aitor; Unzueta, Luis; Galdós, Andoni; Segura, Álvaro

    This work presents an interactive and stereoscopic 3D viewer of weather information coming from a Doppler radar. The hybrid system shows a GIS model of the regional zone where the radar is located and the corresponding reconstructed 3D volume weather data. To enhance the immersiveness of the navigation, stereoscopic visualization has been added to the viewer, using a polarized glasses based system. The user can interact with the 3D virtual world using a Nintendo Wiimote for navigating through it and a Nintendo Wii Nunchuk for giving commands by means of hand gestures. We also present a dynamic gesture recognition procedure that measures the temporal advance of the performed gesture postures. Experimental results show how dynamic gestures are effectively recognized so that a more natural interaction and immersive navigation in the virtual world is achieved.

  18. Effects of Instant Messaging on School Performance in Adolescents.

    PubMed

    Grover, Karan; Pecor, Keith; Malkowski, Michael; Kang, Lilia; Machado, Sasha; Lulla, Roshni; Heisey, David; Ming, Xue

    2016-06-01

    Instant messaging may compromise sleep quality and school performance in adolescents. We aimed to determine associations between nighttime messaging and daytime sleepiness, self-reported sleep parameters, and/or school performance. Students from 3 high schools in New Jersey completed anonymous questionnaires assessing sleep duration, daytime sleepiness, messaging habits, and academic performance. Of the 2,352 students sampled, 1,537 responses were contrasted among grades, sexes, and messaging duration, both before and after lights out. Students who reported longer duration of messaging after lights out were more likely to report a shorter sleep duration, higher rate of daytime sleepiness, and poorer academic performance. Messaging before lights out was not associated with higher rates of daytime sleepiness or poorer academic performance. Females reported more messaging, more daytime sleepiness, and better academic performance than males. There may be an association between text messaging and school performance in this cohort of students.

  19. Effects of Instant Messaging on School Performance in Adolescents.

    PubMed

    Grover, Karan; Pecor, Keith; Malkowski, Michael; Kang, Lilia; Machado, Sasha; Lulla, Roshni; Heisey, David; Ming, Xue

    2016-06-01

    Instant messaging may compromise sleep quality and school performance in adolescents. We aimed to determine associations between nighttime messaging and daytime sleepiness, self-reported sleep parameters, and/or school performance. Students from 3 high schools in New Jersey completed anonymous questionnaires assessing sleep duration, daytime sleepiness, messaging habits, and academic performance. Of the 2,352 students sampled, 1,537 responses were contrasted among grades, sexes, and messaging duration, both before and after lights out. Students who reported longer duration of messaging after lights out were more likely to report a shorter sleep duration, higher rate of daytime sleepiness, and poorer academic performance. Messaging before lights out was not associated with higher rates of daytime sleepiness or poorer academic performance. Females reported more messaging, more daytime sleepiness, and better academic performance than males. There may be an association between text messaging and school performance in this cohort of students. PMID:26762509

  20. Instant magnetic labeling of tumor cells by ultrasound in vitro

    NASA Astrophysics Data System (ADS)

    Mo, Runyang; Yang, Jian; Wu, Ed X.; Lin, Shuyu

    2011-09-01

    Magnetic labeling of living cells creates opportunities for numerous biomedical applications. Here we describe an instantly cell magnetic labeling method based on ultrasound. We present a detailed study on the ultrasound performance of a simple and efficient labeling protocol for H-22 cells in vitro. High frequency focus ultrasound was investigated as an alternative method to achieve instant cell labeling with the magnetic particles without the need for adjunct agents or initiating cell cultures. Mean diameter of 168 nm dextran-T40 coated superparamagnetic iron oxide (SPIO) nanoparticles were prepared by means of classical coprecipitation in solution in our laboratory. H-22 tumor cells suspended in phosphate-buffered saline (PBS, pH=7.2) were exposed to ultrasound at 1.37 MHz for up to 120 s in the presence of SPIOs. The cellular uptake of iron oxide nanoparticles was detected by prussion blue staining. The viability of cells was determined by a trypan blue exclusion test. At 2 W power and 60 s ultrasound exposure in presence of 410 μg/ml SPIOs, H-22 cell labeling efficiency reached 69.4±6.3% and the labeled cells exhibited an iron content of 10.38±2.43 pg per cell. Furthermore, 95.2±3.2% cells remained viable. The results indicated that the ultrasound protocol could be potentially applied to label cells with large-sized magnetic particles. We also calculated the shear stress at the 2 W power and 1.37 MHz used in experiments. The results showed that the shear stress threshold for ultrasonically induced H-22 cell reparable sonoporation was 697 Pa. These findings provide a quantitative guidance in designing ultrasound protocols for cell labeling.

  1. Distributed Adaptive Control: Beyond Single-Instant, Discrete Variables

    NASA Technical Reports Server (NTRS)

    Wolpert, David H.; Bieniawski, Stefan

    2005-01-01

    In extensive form noncooperative game theory, at each instant t, each agent i sets its state x, independently of the other agents, by sampling an associated distribution, q(sub i)(x(sub i)). The coupling between the agents arises in the joint evolution of those distributions. Distributed control problems can be cast the same way. In those problems the system designer sets aspects of the joint evolution of the distributions to try to optimize the goal for the overall system. Now information theory tells us what the separate q(sub i) of the agents are most likely to be if the system were to have a particular expected value of the objective function G(x(sub 1),x(sub 2), ...). So one can view the job of the system designer as speeding an iterative process. Each step of that process starts with a specified value of E(G), and the convergence of the q(sub i) to the most likely set of distributions consistent with that value. After this the target value for E(sub q)(G) is lowered, and then the process repeats. Previous work has elaborated many schemes for implementing this process when the underlying variables x(sub i) all have a finite number of possible values and G does not extend to multiple instants in time. That work also is based on a fixed mapping from agents to control devices, so that the the statistical independence of the agents' moves means independence of the device states. This paper also extends that work to relax all of these restrictions. This extends the applicability of that work to include continuous spaces and Reinforcement Learning. This paper also elaborates how some of that earlier work can be viewed as a first-principles justification of evolution-based search algorithms.

  2. An optimized web-based approach for collaborative stereoscopic medical visualization

    PubMed Central

    Kaspar, Mathias; Parsad, Nigel M; Silverstein, Jonathan C

    2013-01-01

    Objective Medical visualization tools have traditionally been constrained to tethered imaging workstations or proprietary client viewers, typically part of hospital radiology systems. To improve accessibility to real-time, remote, interactive, stereoscopic visualization and to enable collaboration among multiple viewing locations, we developed an open source approach requiring only a standard web browser with no added client-side software. Materials and Methods Our collaborative, web-based, stereoscopic, visualization system, CoWebViz, has been used successfully for the past 2 years at the University of Chicago to teach immersive virtual anatomy classes. It is a server application that streams server-side visualization applications to client front-ends, comprised solely of a standard web browser with no added software. Results We describe optimization considerations, usability, and performance results, which make CoWebViz practical for broad clinical use. We clarify technical advances including: enhanced threaded architecture, optimized visualization distribution algorithms, a wide range of supported stereoscopic presentation technologies, and the salient theoretical and empirical network parameters that affect our web-based visualization approach. Discussion The implementations demonstrate usability and performance benefits of a simple web-based approach for complex clinical visualization scenarios. Using this approach overcomes technical challenges that require third-party web browser plug-ins, resulting in the most lightweight client. Conclusions Compared to special software and hardware deployments, unmodified web browsers enhance remote user accessibility to interactive medical visualization. Whereas local hardware and software deployments may provide better interactivity than remote applications, our implementation demonstrates that a simplified, stable, client approach using standard web browsers is sufficient for high quality three

  3. Windows Instant Messaging App Forensics: Facebook and Skype as Case Studies.

    PubMed

    Yang, Teing Yee; Dehghantanha, Ali; Choo, Kim-Kwang Raymond; Muda, Zaiton

    2016-01-01

    Instant messaging (IM) has changed the way people communicate with each other. However, the interactive and instant nature of these applications (apps) made them an attractive choice for malicious cyber activities such as phishing. The forensic examination of IM apps for modern Windows 8.1 (or later) has been largely unexplored, as the platform is relatively new. In this paper, we seek to determine the data remnants from the use of two popular Windows Store application software for instant messaging, namely Facebook and Skype on a Windows 8.1 client machine. This research contributes to an in-depth understanding of the types of terrestrial artefacts that are likely to remain after the use of instant messaging services and application software on a contemporary Windows operating system. Potential artefacts detected during the research include data relating to the installation or uninstallation of the instant messaging application software, log-in and log-off information, contact lists, conversations, and transferred files.

  4. A Model for the Omnidirectional Acquisition and Rendering of Stereoscopic Images for Human Viewing

    NASA Astrophysics Data System (ADS)

    Gurrieri, Luis E.; Dubois, Eric

    2015-12-01

    Interactive visual media enable the visualization and navigation of remote-world locations in all gaze directions. A large segment of such media is created using pictures from the remote sites thanks to the advance in panoramic cameras. A desirable enhancement is to facilitate the stereoscopic visualization of remote scenes in all gaze directions. In this context, a model for the signal to be acquired by an omnistereoscopic sensor is needed in order to design better acquisition strategies. This omnistereoscopic viewing model must take into account the geometric constraints imposed by our binocular vision system since we want to produce stereoscopic imagery capable to induce stereopsis consistently in any gaze direction; in this paper, we present such model. In addition, we discuss different approaches to sample or to approximate this function and we propose a general acquisition model for sampling the omnistereoscopic light signal. From this model, we propose that by acquiring and mosaicking sparse sets of partially overlapped stereoscopic snapshots, a satisfactory illusion of depth can be evoked. Finally, we show an example of the rendering pipeline to create the omnistereoscopic imagery.

  5. Web GIS in practice VII: stereoscopic 3-D solutions for online maps and virtual globes

    PubMed Central

    Boulos, Maged N Kamel; Robinson, Larry R

    2009-01-01

    Because our pupils are about 6.5 cm apart, each eye views a scene from a different angle and sends a unique image to the visual cortex, which then merges the images from both eyes into a single picture. The slight difference between the right and left images allows the brain to properly perceive the 'third dimension' or depth in a scene (stereopsis). However, when a person views a conventional 2-D (two-dimensional) image representation of a 3-D (three-dimensional) scene on a conventional computer screen, each eye receives essentially the same information. Depth in such cases can only be approximately inferred from visual clues in the image, such as perspective, as only one image is offered to both eyes. The goal of stereoscopic 3-D displays is to project a slightly different image into each eye to achieve a much truer and realistic perception of depth, of different scene planes, and of object relief. This paper presents a brief review of a number of stereoscopic 3-D hardware and software solutions for creating and displaying online maps and virtual globes (such as Google Earth) in "true 3D", with costs ranging from almost free to multi-thousand pounds sterling. A practical account is also given of the experience of the USGS BRD UMESC (United States Geological Survey's Biological Resources Division, Upper Midwest Environmental Sciences Center) in setting up a low-cost, full-colour stereoscopic 3-D system. PMID:19849837

  6. CT virtual endoscopy and 3D stereoscopic visualisation in the evaluation of coronary stenting.

    PubMed

    Sun, Z; Lawrence-Brown

    2009-10-01

    The aim of this case report is to present the additional value provided by CT virtual endoscopy and 3D stereoscopic visualisation when compared with 2D visualisations in the assessment of coronary stenting. A 64-year old patient was treated with left coronary stenting 8 years ago and recently followed up with multidetector row CT angiography. An in-stent restenosis of the left coronary artery was suspected based on 2D axial and multiplanar reformatted images. 3D virtual endoscopy was generated to demonstrate the smooth intraluminal surface of coronary artery wall, and there was no evidence of restenosis or intraluminal irregularity. Virtual fly-through of the coronary artery was produced to examine the entire length of the coronary artery with the aim of demonstrating the intraluminal changes following placement of the coronary stent. In addition, stereoscopic views were generated to show the relationship between coronary artery branches and the coronary stent. In comparison with traditional 2D visualisations, virtual endoscopy was useful for assessment of the intraluminal appearance of the coronary artery wall following coronary stent implantation, while stereoscopic visualisation improved observers' understanding of the complex cardiac structures. Thus, both methods could be used as a complementary tool in cardiac imaging.

  7. Development of a stereoscopic 3D display system to observe restored heritage

    NASA Astrophysics Data System (ADS)

    Morikawa, Hiroyuki; Kawaguchi, Mami; Kawai, Takashi; Ohya, Jun

    2004-05-01

    The authors have developed a binocular-type display system that allows digital archives of cultural assets to be viewed in their actual environment. The system is designed for installation in locations where such cultural assets were originally present. The viewer sees buildings and other heritage items as they existed historically by looking through the binoculars. Images of the cultural assets are reproduced by stereoscopic 3D CG in cyberspace, and the images are superimposed on actual images in real-time. This system consists of stereoscopic CCD cameras that capture a stereo view of the landscape and LCDs for presentation to the viewer. Virtual cameras, used to render CG images from digital archives, move in synchrony with the actual cameras, so the relative position of the CG images and the landscape on which they are superimposed is always fixed. The system has manual controls for digital zoom. Furthermore, the transparency of the CG images can be altered by the viewer. As a case study for the effectiveness of this system, the authors chose the Heijyoukyou ruins in Nara, Japan. The authors evaluate the sense of immersion, stereoscopic effect, and usability of the system.

  8. Using Saliency-Weighted Disparity Statistics for Objective Visual Comfort Assessment of Stereoscopic Images

    NASA Astrophysics Data System (ADS)

    Zhang, Wenlan; Luo, Ting; Jiang, Gangyi; Jiang, Qiuping; Ying, Hongwei; Lu, Jing

    2016-06-01

    Visual comfort assessment (VCA) for stereoscopic images is a particularly significant yet challenging task in 3D quality of experience research field. Although the subjective assessment given by human observers is known as the most reliable way to evaluate the experienced visual discomfort, it is time-consuming and non-systematic. Therefore, it is of great importance to develop objective VCA approaches that can faithfully predict the degree of visual discomfort as human beings do. In this paper, a novel two-stage objective VCA framework is proposed. The main contribution of this study is that the important visual attention mechanism of human visual system is incorporated for visual comfort-aware feature extraction. Specifically, in the first stage, we first construct an adaptive 3D visual saliency detection model to derive saliency map of a stereoscopic image, and then a set of saliency-weighted disparity statistics are computed and combined to form a single feature vector to represent a stereoscopic image in terms of visual comfort. In the second stage, a high dimensional feature vector is fused into a single visual comfort score by performing random forest algorithm. Experimental results on two benchmark databases confirm the superior performance of the proposed approach.

  9. The right view from the wrong location: depth perception in stereoscopic multi-user virtual environments.

    PubMed

    Pollock, Brice; Burton, Melissa; Kelly, Jonathan W; Gilbert, Stephen; Winer, Eliot

    2012-04-01

    Stereoscopic depth cues improve depth perception and increase immersion within virtual environments (VEs). However, improper display of these cues can distort perceived distances and directions. Consider a multi-user VE, where all users view identical stereoscopic images regardless of physical location. In this scenario, cues are typically customized for one "leader" equipped with a head-tracking device. This user stands at the center of projection (CoP) and all other users ("followers") view the scene from other locations and receive improper depth cues. This paper examines perceived depth distortion when viewing stereoscopic VEs from follower perspectives and the impact of these distortions on collaborative spatial judgments. Pairs of participants made collaborative depth judgments of virtual shapes viewed from the CoP or after displacement forward or backward. Forward and backward displacement caused perceived depth compression and expansion, respectively, with greater compression than expansion. Furthermore, distortion was less than predicted by a ray-intersection model of stereo geometry. Collaboration times were significantly longer when participants stood at different locations compared to the same location, and increased with greater perceived depth discrepancy between the two viewing locations. These findings advance our understanding of spatial distortions in multi-user VEs, and suggest a strategy for reducing distortion.

  10. Field trials of stereoscopic video with an underwater remotely operated vehicle

    NASA Astrophysics Data System (ADS)

    Woods, Andrew J.; Docherty, Tom; Koch, Rolf

    1994-04-01

    We have developed a flicker-free stereoscopic video system which uses commercial television components. This system has been installed on an underwater remotely operated vehicle (ROV) that is used for service and inspection tasks at a gas production platform 130 km off the North-West coast of Western Australia. We report the results of field and laboratory time trials of remote manipulation tasks and also the general experience gained in the field operation of the system. Stereoscopic video provides the operator with an intuitive sense of the depth relationships of the work site. Operators report that this reduces frustration and mental effort as well as giving them confidence in their actions. Some of the other advantages that we have observed include the increased ability to see through suspended matter (fine particles) in the water. The system is most useful in manipulative tasks but also useful for general `flying' of the ROV making navigation through the platform easier. Our results indicate that stereoscopic video will be a valuable tool in the operation of remotely operated vehicles in the underwater environment.

  11. Monoscopic versus stereoscopic photography in screening for clinically significant macular edema.

    PubMed

    Welty, Christopher J; Agarwal, Anita; Merin, Lawrence M; Chomsky, Amy

    2006-01-01

    The purpose of the study was to determine whether monoscopic photography could serve as an accurate tool when used to screen for clinically significant macular edema. In a masked randomized fashion, two readers evaluated monoscopic and stereoscopic retinal photographs of 100 eyes. The photographs were evaluated first individually for probable clinically significant macular edema based on the Early Treatment Diabetic Retinopathy Study criteria and then as stereoscopic pairs. Graders were evaluated for sensitivity and specificity individually and in combination. Individually, reader one had a sensitivity of 0.93 and a specificity of 0.77, and reader two had a sensitivity of 0.88 and a specificity of 0.94. In combination, the readers had a sensitivity of 0.91 and a specificity of 0.86. They correlated on 0.76 of the stereoscopic readings and 0.92 of the monoscopic readings. These results indicate that the use of monoscopic retinal photography may be an accurate screening tool for clinically significant macular edema.

  12. Case study: the introduction of stereoscopic games on the Sony PlayStation 3

    NASA Astrophysics Data System (ADS)

    Bickerstaff, Ian

    2012-03-01

    A free stereoscopic firmware update on Sony Computer Entertainment's PlayStation® 3 console provides the potential to increase enormously the popularity of stereoscopic 3D in the home. For this to succeed though, a large selection of content has to become available that exploits 3D in the best way possible. In addition to the existing challenges found in creating 3D movies and television programmes, the stereography must compensate for the dynamic and unpredictable environments found in games. Automatically, the software must map the depth range of the scene into the display's comfort zone, while minimising depth compression. This paper presents a range of techniques developed to solve this problem and the challenge of creating twice as many images as the 2D version without excessively compromising the frame rate or image quality. At the time of writing, over 80 stereoscopic PlayStation 3 games have been released and notable titles are used as examples to illustrate how the techniques have been adapted for different game genres. Since the firmware's introduction in 2010, the industry has matured with a large number of developers now producing increasingly sophisticated 3D content. New technologies such as viewer head tracking and head-mounted displays should increase the appeal of 3D in the home still further.

  13. Spatial visualization ability and laparoscopic skills in novice learners: evaluating stereoscopic versus monoscopic visualizations.

    PubMed

    Roach, Victoria A; Mistry, Manisha R; Wilson, Timothy D

    2014-01-01

    Elevated spatial visualization ability (Vz) is thought to influence surgical skill acquisition and performance. Current research suggests that stereo visualization technology and its association with skill performance may confer perceptual advantages. This is of particular interest in laparoscopic skill training, where stereo visualization may confer learning advantages to novices of variant Vz. This study explored laparoscopic skill performance scores in novices with variable spatial ability utilizing stereoscopic and traditional monoscopic visualization paradigms. Utilizing the McGill Inanimate System for Teaching and Evaluating Laparoscopic Skills (MISTELS) scoring protocol it was hypothesized that individuals with high spatial visualization ability (HVz) would achieve higher overall and individual MISTELS task scores as compared to low spatial visualization ability (LVz) counterparts. Further, we also hypothesized that a difference would exist between HVz and LVz individual scores based on the viewing modality employed. No significant difference was observed between HVz and LVz individuals for MISTELS tasks scores, overall or individually under both viewing modalities, despite higher average MISTELS scores for HVz individuals. The lack of difference between scores obtained under the stereo modality suggested that the additional depth that is conferred by the stereoscopic visualization may act to enhance performance for individuals with LVz, potentially equilibrating their performance with their HVz peers. Further experimentation is required to better ascertain the effects of stereo visualization in individuals of high and low Vz, though it appears stereoscopic visualizations could serve as a prosthetic to enhance skill performance.

  14. Why 3D Cameras are Not Popular: A Qualitative User Study on Stereoscopic Photography Acceptance

    NASA Astrophysics Data System (ADS)

    Hakala, Jussi; Westman, Stina; Salmimaa, Marja; Pölönen, Monika; Järvenpää, Toni; Häkkinen, Jukka

    2014-03-01

    Digital stereoscopic 3D cameras have entered the consumer market in recent years, but the acceptance of this novel technology has not yet been studied. The aim of this study was to identify the benefits and problems that novice users encounter in 3D photography by equipping five users with 3D cameras for a 4-week trial. We gathered data using a weekly questionnaire, an exit interview, and a stereoscopic disparity analysis of the 699 photographs taken during the trial. The results indicate that the participants took photographs at too-close distances, which caused excessive disparities. They learned to avoid the problem to some extent; the number of failed photographs due to excessive stereoscopic disparity decreased 70 % in 4 weeks. The participants also developed a preference for subjects that included clear depth differences and started to avoid photographing people because they looked unnatural in 3D photographs. They also regarded flash-induced shadows and edge violations problematic because of the unnatural effects in the photographs. We propose in-camera assistance tools for 3D cameras to make 3D photography easier.

  15. Web GIS in practice VII: stereoscopic 3-D solutions for online maps and virtual globes

    USGS Publications Warehouse

    Boulos, Maged N.K.; Robinson, Larry R.

    2009-01-01

    Because our pupils are about 6.5 cm apart, each eye views a scene from a different angle and sends a unique image to the visual cortex, which then merges the images from both eyes into a single picture. The slight difference between the right and left images allows the brain to properly perceive the 'third dimension' or depth in a scene (stereopsis). However, when a person views a conventional 2-D (two-dimensional) image representation of a 3-D (three-dimensional) scene on a conventional computer screen, each eye receives essentially the same information. Depth in such cases can only be approximately inferred from visual clues in the image, such as perspective, as only one image is offered to both eyes. The goal of stereoscopic 3-D displays is to project a slightly different image into each eye to achieve a much truer and realistic perception of depth, of different scene planes, and of object relief. This paper presents a brief review of a number of stereoscopic 3-D hardware and software solutions for creating and displaying online maps and virtual globes (such as Google Earth) in "true 3D", with costs ranging from almost free to multi-thousand pounds sterling. A practical account is also given of the experience of the USGS BRD UMESC (United States Geological Survey's Biological Resources Division, Upper Midwest Environmental Sciences Center) in setting up a low-cost, full-colour stereoscopic 3-D system.

  16. Stereoscopic display employing head-position tracking using large format lenses

    NASA Astrophysics Data System (ADS)

    Hattori, Tomohiko

    1993-09-01

    Two stereoscopic systems are described which permits the observation of a high resolution image by several persons simultaneously and suited to mass production. One is a time- parallel method and another is a time-interlaced method. In the time-parallel stereoscopic display system, by mechanically driving several video projectors according to the observers' eye position, the images projected on a large format convex lenses are varied, the left image rays continuously entering the observers' left eyes and vice versa. In the time-interlaced stereoscopic display system, the image output screen is formed by a transparent type color liquid crystal plate with a large format lens. The lens is arranged so that an image of viewers is projected to the plane of a black-and-white CRT which is positioned behind as a back light of the system. To view the stereo image on the color liquid crystal plate, the alternating left- and right-eye perspectives must be synchronized with an infrared lightening system and the imaging of the viewers on the CRT that the back light distributes the light to the left eyes when the left-eye view is displayed on the color liquid crystal plate and vice versa.

  17. Comprehensive depth estimation algorithm for efficient stereoscopic content creation in three-dimensional video systems

    NASA Astrophysics Data System (ADS)

    Xu, Huihui; Jiang, Mingyan

    2015-07-01

    Two-dimensional to three-dimensional (3-D) conversion in 3-D video applications has attracted great attention as it can alleviate the problem of stereoscopic content shortage. Depth estimation is an essential part of this conversion since the depth accuracy directly affects the quality of a stereoscopic image. In order to generate a perceptually reasonable depth map, a comprehensive depth estimation algorithm that considers the scenario type is presented. Based on the human visual system mechanism, which is sensitive to a change in the scenario, this study classifies the type of scenario into four classes according to the relationship between the movements of the camera and the object, and then leverages different strategies on the basis of the scenario type. The proposed strategies efficiently extract the depth information from different scenarios. In addition, the depth generation method for a scenario in which there is no motion, neither of the object nor the camera, is also suitable for the single image. Qualitative and quantitative evaluation results demonstrate that the proposed depth estimation algorithm is very effective for generating stereoscopic content and providing a realistic visual experience.

  18. Effect of accommodation training by stereoscopic movie presentation on myopic youth

    NASA Astrophysics Data System (ADS)

    Sugiura, A.; Takada, H.; Yamamoto, T.; Miyao, M.

    2010-02-01

    The abnormal contraction of ciliary muscles due to the performance of a near visual task for several hours causes various vision problems such as asthenopia and visual loss. However, these problems can be resolved by activating the muscles by alternately repeating negative and positive accommodation. In this study, we have verified the effect of accommodation training that uses the strategy of presenting a stereoscopic movie to myopic youth and measuring the uncorrected distant visual acuity, spherical diopter (SPH), and subjective index of asthenopia obtained using a visual analog scale (VAS). Stereoscopic movies are prepared by using the POWER 3D method (Olympus Visual Communications Co., Ltd.), which reduces the inconsistency between the experienced and the actual senses. Thirty two myopic students aged 20 +/- 1 years (16 males and 16 females) were chosen as the subjects. One group performed the accommodation training for 6 min, and the other group underwent a near visual task during the same period as the control group. We concluded the following from each item of verification: (a) The accommodation training using a stereoscopic movie had temporarily improved visual acuity. (b) This training led to a decrease in asthenopia. (c) The training improved the near-point accommodation function.

  19. Pseudolocal tomography

    DOEpatents

    Katsevich, A.J.; Ramm, A.G.

    1996-07-23

    Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density. 7 figs.

  20. Pseudolocal tomography

    DOEpatents

    Katsevich, Alexander J.; Ramm, Alexander G.

    1996-01-01

    Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density.

  1. Can the perception of depth in stereoscopic images be influenced by 3D sound?

    NASA Astrophysics Data System (ADS)

    Turner, Amy; Berry, Jonathan; Holliman, Nick

    2011-03-01

    The creation of binocular images for stereoscopic display has benefited from significant research and commercial development in recent years. However, perhaps surprisingly, the effect of adding 3D sound to stereoscopic images has rarely been studied. If auditory depth information can enhance or extend the visual depth experience it could become an important way to extend the limited depth budget on all 3D displays and reduce the potential for fatigue from excessive use of disparity. Objective: As there is limited research in this area our objective was to ask two preliminary questions. First what is the smallest difference in forward depth that can be reliably detected using 3D sound alone? Second does the addition of auditory depth information influence the visual perception of depth in a stereoscopic image? Method: To investigate auditory depth cues we use a simple sound system to test the experimental hypothesis that: participants will perform better than chance at judging the depth differences between two speakers a set distance apart. In our second experiment investigating both auditory and visual depth cues we setup a sound system and a stereoscopic display to test the experimental hypothesis that: participants judge a visual stimulus to be closer if they hear a closer sound when viewing the stimulus. Results: In the auditory depth cue trial every depth difference tested gave significant results demonstrating that the human ear can hear depth differences between physical sources as short as 0.25 m at 1 m. In our trial investigating whether audio information can influence the visual perception of depth we found that participants did report visually perceiving an object to be closer when the sound was played closer to them even though the image depth remained unchanged. Conclusion: The positive results in the two trials show that we can hear small differences in forward depth between sound sources and suggest that it could be practical to extend the apparent

  2. Seismic Tomography.

    ERIC Educational Resources Information Center

    Anderson, Don L.; Dziewonski, Adam M.

    1984-01-01

    Describes how seismic tomography is used to analyze the waves produced by earthquakes. The information obtained from the procedure can then be used to map the earth's mantle in three dimensions. The resulting maps are then studied to determine such information as the convective flow that propels the crustal plates. (JN)

  3. Using Instant Messaging Systems as a Platform for Electronic Voting

    NASA Astrophysics Data System (ADS)

    Meletiadou, Anastasia; Grimm, Rüdiger

    Many Instant Messaging (IM) systems like Skype or Spark offer ex tended services such as file sharing, VoIP, or a shared whiteboard. As the name suggests, IM applications are predominantly used for spontaneous text-based communication for private or business purposes. In this paper we explore their potential to serve as platforms for secure collaborative applications like electronic contract negotiation, e-payment or electronic voting. Such applications have to deal with challenges like time constraints (“instant” com munication is desired), integration of media channels and the absence of one uni fying “sphere of control” covering all participants. In this paper, we address these challenges by discussing one particular secure collaborative application: secure decision processes for small groups. We provide the following contribu tions: (1) we define three varying scenarios and corresponding security require ments (2) we present an IM-based architecture implementing these scenarios, in cluding a Video-based authentication mechanism, and (3) we discuss poten tial attack patterns.

  4. Antitussive and immunomodulating activities of instant coffee arabinogalactan-protein.

    PubMed

    Nosáľová, G; Prisenžňáková, L; Paulovičová, E; Capek, P; Matulová, M; Navarini, L; Liverani, F Suggi

    2011-11-01

    A low molecular mass arabinogalactan-protein (AGP) composed of galactose and arabinose with a low protein content, isolated from the instant coffee powder of Coffea arabica beans, has been tested on antitussive (in vivo) and immunomodulating (ex vivo) activities. The results of antitussive tests revealed a significant dose dependant cough-suppressive effect of coffee AGP. It was observed 30 or 60 min after AGP administration and its efficacy lasted during the entire experiment course. Immunological tests showed that AGP affected some mediators of immunocompetent cells of immune system as TNF-α, IFN-γ and IL-2 cytokines. It seems that coffee AGP is a good inductor of both pro-inflammatory cytokines TNF-α and IFN-γ, however, less potent in TNF-α induction in comparison with that of β-D-glucan. Evident induction of TNF-α, IL-2 and IFN-γ cytokines, pro-TH1 polarization supports our conclusion about bio-immunological efficacy of AGP with an emphasis on the cellular immunity.

  5. Investigation of flow structure on a stationary and pitching delta wing of moderate sweep angle using stereoscopic particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Goruney, Tunc

    Near-surface flow patterns along a basic delta wing of moderate sweep angle, representative of key features of Unmanned Combat Air Vehicles (UCAVs) and Micro Air Vehicles (MAVs), are visualized by a technique of high-image-density digital particle image velocimetry (DPIV), which provides quantitative representations of the whole-field flow patterns. Due to the highly three-dimensional nature of the flow patterns, they are also visualized by stereoscopic particle image velocimetry (SPIV). Qualitative dye visualization is employed to complement the DPIV technique. The flow structure is represented by patterns of dye, velocity vectors, streamwise, transverse and out-of-plane velocity components, streamline topology and vorticity. The surface topology, i.e., surface streamlines, and patterns of surface velocity and vorticity oriented normal to the surface of the wing, are investigated by making use of topological rules and critical point theory. For the case of DPIV measurements, the focus is on the time evolution of the surface topology during relaxation of the flow after termination of a pitching maneuver, for a wide range of pitch rates. It is demonstrated that there exists a critical universal state, which marks an abrupt transformation between two distinctly different states of the near-surface pattern of critical points. Moreover, an approach that predicts the occurrence of three-dimensional separation from the surface of the wing, for a wide range of pitch rate, is introduced. For the case of SPIV measurements, the relationship between the three-dimensional flow structure above the surface of the wing and the near-surface topology along the wing has been established, at successive instants following termination of the maneuver. Features of the leading-edge vortex and its breakdown location were quantitatively determined at the termination of the pitching maneuver. For the relaxed state of the flow structure, there is a reference elevation above the wing surface

  6. Stereoscopic Imaging in Hypersonics Boundary Layers using Planar Laser-Induced Fluorescence

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Bathel, Brett; Inman, Jennifer A.; Alderfer, David W.; Jones, Stephen B.

    2008-01-01

    Stereoscopic time-resolved visualization of three-dimensional structures in a hypersonic flow has been performed for the first time. Nitric Oxide (NO) was seeded into hypersonic boundary layer flows that were designed to transition from laminar to turbulent. A thick laser sheet illuminated and excited the NO, causing spatially-varying fluorescence. Two cameras in a stereoscopic configuration were used to image the fluorescence. The images were processed in a computer visualization environment to provide stereoscopic image pairs. Two methods were used to display these image pairs: a cross-eyed viewing method which can be viewed by naked eyes, and red/blue anaglyphs, which require viewing through red/blue glasses. The images visualized three-dimensional information that would be lost if conventional planar laser-induced fluorescence imaging had been used. Two model configurations were studied in NASA Langley Research Center's 31-Inch Mach 10 Air Wind tunnel. One model was a 10 degree half-angle wedge containing a small protuberance to force the flow to transition. The other model was a 1/3-scale, truncated Hyper-X forebody model with blowing through a series of holes to force the boundary layer flow to transition to turbulence. In the former case, low flowrates of pure NO seeded and marked the boundary layer fluid. In the latter, a trace concentration of NO was seeded into the injected N2 gas. The three-dimensional visualizations have an effective time resolution of about 500 ns, which is fast enough to freeze this hypersonic flow. The 512x512 resolution of the resulting images is much higher than high-speed laser-sheet scanning systems with similar time response, which typically measure 10-20 planes.

  7. Computer-enhanced stereoscopic vision in a head-mounted operating binocular.

    PubMed

    Birkfellner, Wolfgang; Figl, Michael; Matula, Christian; Hummel, Johann; Hanel, Rudolf; Imhof, Herwig; Wanschitz, Felix; Wagner, Arne; Watzinger, Franz; Bergmann, Helmar

    2003-02-01

    Based on the Varioscope, a commercially available head-mounted operating binocular, we have developed the Varioscope AR, a see through head-mounted display (HMD) for augmented reality visualization that seamlessly fits into the infrastructure of a surgical navigation system. We have assessed the extent to which stereoscopic visualization improves target localization in computer-aided surgery in a phantom study. In order to quantify the depth perception of a user aiming at a given target, we have designed a phantom simulating typical clinical situations in skull base surgery. Sixteen steel spheres were fixed at the base of a bony skull, and several typical craniotomies were applied. After having taken CT scans, the skull was filled with opaque jelly in order to simulate brain tissue. The positions of the spheres were registered using VISIT, a system for computer-aided surgical navigation. Then attempts were made to locate the steel spheres with a bayonet probe through the craniotomies using VISIT and the Varioscope AR as a stereoscopic display device. Localization of targets 4 mm in diameter using stereoscopic vision and additional visual cues indicating target proximity had a success rate (defined as a first-trial hit rate) of 87.5%. Using monoscopic vision and target proximity indication, the success rate was found to be 66.6%. Omission of visual hints on reaching a target yielded a success rate of 79.2% in the stereo case and 56.25% with monoscopic vision. Time requirements for localizing all 16 targets ranged from 7.5 min (stereo, with proximity cues) to 10 min (mono, without proximity cues). Navigation error is primarily governed by the accuracy of registration in the navigation system, whereas the HMD does not appear to influence localization significantly. We conclude that stereo vision is a valuable tool in augmented reality guided interventions. PMID:12608617

  8. Depth-of-Focus Affects 3D Perception in Stereoscopic Displays.

    PubMed

    Vienne, Cyril; Blondé, Laurent; Mamassian, Pascal

    2015-01-01

    Stereoscopic systems present binocular images on planar surface at a fixed distance. They induce cues to flatness, indicating that images are presented on a unique surface and specifying the relative depth of that surface. The center of interest of this study is on a second problem, arising when a 3D object distance differs from the display distance. As binocular disparity must be scaled using an estimate of viewing distance, object depth can thus be affected through disparity scaling. Two previous experiments revealed that stereoscopic displays can affect depth perception due to conflicting accommodation and vergence cues at near distances. In this study, depth perception is evaluated for farther accommodation and vergence distances using a commercially available 3D TV. In Experiment I, we evaluated depth perception of 3D stimuli at different vergence distances for a large pool of participants. We observed a strong effect of vergence distance that was bigger for younger than for older participants, suggesting that the effect of accommodation was reduced in participants with emerging presbyopia. In Experiment 2, we extended 3D estimations by varying both the accommodation and vergence distances. We also tested the hypothesis that setting accommodation open loop by constricting pupil size could decrease the contribution of focus cues to perceived distance. We found that the depth constancy was affected by accommodation and vergence distances and that the accommodation distance effect was reduced with a larger depth-of-focus. We discuss these results with regard to the effectiveness of focus cues as a distance signal. Overall, these results highlight the importance of appropriate focus cues in stereoscopic displays at intermediate viewing distances.

  9. Instant noodles as an antifriction device: making the BOP with PPP in PNG.

    PubMed

    Errington, Frederick; Fujikura, Tatsuro; Gewertz, Deborah

    2012-01-01

    Focusing primarily, but not exclusively, on urban and periurban Papua New Guinea (PNG), we discuss the significance of instant ramen noodles to those now known as the “bottom of the pyramid” (BOP). Although instant noodles are remarkable in that they are eaten by virtually everyone in the world, albeit in different amounts and for different reasons, they are marketed in PNG specifically as a “popularly positioned product” (PPP) for the BOP. Cheap, convenient, tasty, filling, and shelf stable, they are a modern addition to Sidney Mintz's classic “proletarian hunger killers” of sugar, tea, and coffee. But, we argue, instant noodles have a distinctive contemporary role: they do more than sustain the poor; they transform them into the aspiring consumers of the BOP. As such, instant noodles can be viewed as an antifriction device, greasing the skids of capitalism as it extends its reach. PMID:22662351

  10. Instant noodles as an antifriction device: making the BOP with PPP in PNG.

    PubMed

    Errington, Frederick; Fujikura, Tatsuro; Gewertz, Deborah

    2012-01-01

    Focusing primarily, but not exclusively, on urban and periurban Papua New Guinea (PNG), we discuss the significance of instant ramen noodles to those now known as the “bottom of the pyramid” (BOP). Although instant noodles are remarkable in that they are eaten by virtually everyone in the world, albeit in different amounts and for different reasons, they are marketed in PNG specifically as a “popularly positioned product” (PPP) for the BOP. Cheap, convenient, tasty, filling, and shelf stable, they are a modern addition to Sidney Mintz's classic “proletarian hunger killers” of sugar, tea, and coffee. But, we argue, instant noodles have a distinctive contemporary role: they do more than sustain the poor; they transform them into the aspiring consumers of the BOP. As such, instant noodles can be viewed as an antifriction device, greasing the skids of capitalism as it extends its reach.

  11. System design description for the LDUA high resolution stereoscopic video camera system (HRSVS)

    SciTech Connect

    Pardini, A.F.

    1998-01-27

    The High Resolution Stereoscopic Video Camera System (HRSVS), system 6230, was designed to be used as an end effector on the LDUA to perform surveillance and inspection activities within a waste tank. It is attached to the LDUA by means of a Tool Interface Plate (TIP) which provides a feed through for all electrical and pneumatic utilities needed by the end effector to operate. Designed to perform up close weld and corrosion inspection roles in US T operations, the HRSVS will support and supplement the Light Duty Utility Arm (LDUA) and provide the crucial inspection tasks needed to ascertain waste tank condition.

  12. How much crosstalk can be allowed in a stereoscopic system at various grey levels?

    NASA Astrophysics Data System (ADS)

    Shestak, Sergey; Kim, Daesik; Kim, Yongie

    2012-03-01

    We have calculated a perceptual threshold of stereoscopic crosstalk on the basis of mathematical model of human vision sensitivity. Instead of linear model of just noticeable difference (JND) known as Weber's law we applied nonlinear Barten's model. The predicted crosstalk threshold varies with the background luminance. The calculated values of threshold are in a reasonable agreement with known experimental data. We calculated perceptual threshold of crosstalk for various combinations of the applied grey level. This result can be applied for the assessment of grey-to-grey crosstalk compensation. Further computational analysis of the applied model predicts the increase of the displayable image contrast with reduction of the maximum displayable luminance.

  13. Display depth analyses with the wave aberration for the auto-stereoscopic 3D display

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Sang, Xinzhu; Yu, Xunbo; Chen, Duo; Chen, Zhidong; Zhang, Wanlu; Yan, Binbin; Yuan, Jinhui; Wang, Kuiru; Yu, Chongxiu; Dou, Wenhua; Xiao, Liquan

    2016-07-01

    Because the aberration severely affects the display performances of the auto-stereoscopic 3D display, the diffraction theory is used to analyze the diffraction field distribution and the display depth through aberration analysis. Based on the proposed method, the display depth of central and marginal reconstructed images is discussed. The experimental results agree with the theoretical analyses. Increasing the viewing distance or decreasing the lens aperture can improve the display depth. Different viewing distances and the LCD with two lens-arrays are used to verify the conclusion.

  14. The DextroBeam: a stereoscopic presentation system for volumetric medical data.

    PubMed

    Serra, Luis; Kockro, Ralf; Goh, Lin Chia; Ng, Hem; Lee, Eugene Chee Keong

    2002-01-01

    This paper describes an interaction system called the DextroBeam designed for manipulating objects in 3D space while looking at a 3D stereoscopic display located in front of the user. Three-dimensional interaction is two-handed and is achieved by means of a stylus with a single button or switch. We have been planning several neurosurgical cases with the DextroBeam, including the separation of Nepalese Siamese twins in April 2001, and have conducted a course on surgery of the Temporal Bone (as part of the 9th ASEAN ORL Head and Neck Congress in Singapore, March 2001).

  15. Correlative Tomography

    PubMed Central

    Burnett, T. L.; McDonald, S. A.; Gholinia, A.; Geurts, R.; Janus, M.; Slater, T.; Haigh, S. J.; Ornek, C.; Almuaili, F.; Engelberg, D. L.; Thompson, G. E.; Withers, P. J.

    2014-01-01

    Increasingly researchers are looking to bring together perspectives across multiple scales, or to combine insights from different techniques, for the same region of interest. To this end, correlative microscopy has already yielded substantial new insights in two dimensions (2D). Here we develop correlative tomography where the correlative task is somewhat more challenging because the volume of interest is typically hidden beneath the sample surface. We have threaded together x-ray computed tomography, serial section FIB-SEM tomography, electron backscatter diffraction and finally TEM elemental analysis all for the same 3D region. This has allowed observation of the competition between pitting corrosion and intergranular corrosion at multiple scales revealing the structural hierarchy, crystallography and chemistry of veiled corrosion pits in stainless steel. With automated correlative workflows and co-visualization of the multi-scale or multi-modal datasets the technique promises to provide insights across biological, geological and materials science that are impossible using either individual or multiple uncorrelated techniques. PMID:24736640

  16. Correlative Tomography

    NASA Astrophysics Data System (ADS)

    Burnett, T. L.; McDonald, S. A.; Gholinia, A.; Geurts, R.; Janus, M.; Slater, T.; Haigh, S. J.; Ornek, C.; Almuaili, F.; Engelberg, D. L.; Thompson, G. E.; Withers, P. J.

    2014-04-01

    Increasingly researchers are looking to bring together perspectives across multiple scales, or to combine insights from different techniques, for the same region of interest. To this end, correlative microscopy has already yielded substantial new insights in two dimensions (2D). Here we develop correlative tomography where the correlative task is somewhat more challenging because the volume of interest is typically hidden beneath the sample surface. We have threaded together x-ray computed tomography, serial section FIB-SEM tomography, electron backscatter diffraction and finally TEM elemental analysis all for the same 3D region. This has allowed observation of the competition between pitting corrosion and intergranular corrosion at multiple scales revealing the structural hierarchy, crystallography and chemistry of veiled corrosion pits in stainless steel. With automated correlative workflows and co-visualization of the multi-scale or multi-modal datasets the technique promises to provide insights across biological, geological and materials science that are impossible using either individual or multiple uncorrelated techniques.

  17. A stereoscopic system for viewing the temporal evolution of brain activity clusters in response to linguistic stimuli.

    PubMed

    Forbes, Angus; Villegas, Javier; Almryde, Kyle R; Plante, Elena

    2014-03-01

    In this paper, we present a novel application, 3D+Time Brain View, for the stereoscopic visualization of functional Magnetic Resonance Imaging (fMRI) data gathered from participants exposed to unfamiliar spoken languages. An analysis technique based on Independent Component Analysis (ICA) is used to identify statistically significant clusters of brain activity and their changes over time during different testing sessions. That is, our system illustrates the temporal evolution of participants' brain activity as they are introduced to a foreign language through displaying these clusters as they change over time. The raw fMRI data is presented as a stereoscopic pair in an immersive environment utilizing passive stereo rendering. The clusters are presented using a ray casting technique for volume rendering. Our system incorporates the temporal information and the results of the ICA into the stereoscopic 3D rendering, making it easier for domain experts to explore and analyze the data.

  18. Towards An Understanding of Mobile Touch Navigation in a Stereoscopic Viewing Environment for 3D Data Exploration.

    PubMed

    López, David; Oehlberg, Lora; Doger, Candemir; Isenberg, Tobias

    2016-05-01

    We discuss touch-based navigation of 3D visualizations in a combined monoscopic and stereoscopic viewing environment. We identify a set of interaction modes, and a workflow that helps users transition between these modes to improve their interaction experience. In our discussion we analyze, in particular, the control-display space mapping between the different reference frames of the stereoscopic and monoscopic displays. We show how this mapping supports interactive data exploration, but may also lead to conflicts between the stereoscopic and monoscopic views due to users' movement in space; we resolve these problems through synchronization. To support our discussion, we present results from an exploratory observational evaluation with domain experts in fluid mechanics and structural biology. These experts explored domain-specific datasets using variations of a system that embodies the interaction modes and workflows; we report on their interactions and qualitative feedback on the system and its workflow.

  19. A stereoscopic system for viewing the temporal evolution of brain activity clusters in response to linguistic stimuli

    NASA Astrophysics Data System (ADS)

    Forbes, Angus; Villegas, Javier; Almryde, Kyle R.; Plante, Elena

    2014-03-01

    In this paper, we present a novel application, 3D+Time Brain View, for the stereoscopic visualization of functional Magnetic Resonance Imaging (fMRI) data gathered from participants exposed to unfamiliar spoken languages. An analysis technique based on Independent Component Analysis (ICA) is used to identify statistically significant clusters of brain activity and their changes over time during different testing sessions. That is, our system illustrates the temporal evolution of participants' brain activity as they are introduced to a foreign language through displaying these clusters as they change over time. The raw fMRI data is presented as a stereoscopic pair in an immersive environment utilizing passive stereo rendering. The clusters are presented using a ray casting technique for volume rendering. Our system incorporates the temporal information and the results of the ICA into the stereoscopic 3D rendering, making it easier for domain experts to explore and analyze the data.

  20. Towards An Understanding of Mobile Touch Navigation in a Stereoscopic Viewing Environment for 3D Data Exploration.

    PubMed

    López, David; Oehlberg, Lora; Doger, Candemir; Isenberg, Tobias

    2016-05-01

    We discuss touch-based navigation of 3D visualizations in a combined monoscopic and stereoscopic viewing environment. We identify a set of interaction modes, and a workflow that helps users transition between these modes to improve their interaction experience. In our discussion we analyze, in particular, the control-display space mapping between the different reference frames of the stereoscopic and monoscopic displays. We show how this mapping supports interactive data exploration, but may also lead to conflicts between the stereoscopic and monoscopic views due to users' movement in space; we resolve these problems through synchronization. To support our discussion, we present results from an exploratory observational evaluation with domain experts in fluid mechanics and structural biology. These experts explored domain-specific datasets using variations of a system that embodies the interaction modes and workflows; we report on their interactions and qualitative feedback on the system and its workflow. PMID:27045916

  1. A study of image exposure for the stereoscopic visualization of sparkling materials

    NASA Astrophysics Data System (ADS)

    Medina, Victor; Paljic, Alexis; Lafon-Pham, Dominique

    2015-01-01

    This work is performed as part of the perceptual validation stage in the stereoscopic visualization of computer- generated (CG) images of materials (typically car paints) containing sparkling metallic flakes. The perceived material aspect is closely linked to the flake density, depth, and sparkling; in turn, our perception of an image of said materials is strongly dependent on the image exposure, that is, the amount of light entering the sensor during the imaging process. Indeed, a high exposure may over saturate the image, reducing discrimination amongst high-luminance flakes, affecting the perceived depth; on the other hand, a low exposure may reduce image contrast, merging low-luminance flakes with the background, and reducing perceived flake density and sparkling. In order to choose the right exposure for each CG image, we have performed a user study where we presented observers with a series of stereoscopic photographs of plates, taken at different exposures with a radiometrically color-calibrated camera ,5 and asked them to assess each photograph's similarity to a physical reference. We expect these results to help us find a correlation between optical settings and visual perception regarding the aforementioned parameters, which we could then use in the rendering process to obtain the desired material aspect.

  2. Assessing the precision of gaze following using a stereoscopic 3D virtual reality setting.

    PubMed

    Atabaki, Artin; Marciniak, Karolina; Dicke, Peter W; Thier, Peter

    2015-07-01

    Despite the ecological importance of gaze following, little is known about the underlying neuronal processes, which allow us to extract gaze direction from the geometric features of the eye and head of a conspecific. In order to understand the neuronal mechanisms underlying this ability, a careful description of the capacity and the limitations of gaze following at the behavioral level is needed. Previous studies of gaze following, which relied on naturalistic settings have the disadvantage of allowing only very limited control of potentially relevant visual features guiding gaze following, such as the contrast of iris and sclera, the shape of the eyelids and--in the case of photographs--they lack depth. Hence, in order to get full control of potentially relevant features we decided to study gaze following of human observers guided by the gaze of a human avatar seen stereoscopically. To this end we established a stereoscopic 3D virtual reality setup, in which we tested human subjects' abilities to detect at which target a human avatar was looking at. Following the gaze of the avatar showed all the features of the gaze following of a natural person, namely a substantial degree of precision associated with a consistent pattern of systematic deviations from the target. Poor stereo vision affected performance surprisingly little (only in certain experimental conditions). Only gaze following guided by targets at larger downward eccentricities exhibited a differential effect of the presence or absence of accompanying movements of the avatar's eyelids and eyebrows. PMID:25982719

  3. Employing WebGL to develop interactive stereoscopic 3D content for use in biomedical visualization

    NASA Astrophysics Data System (ADS)

    Johnston, Semay; Renambot, Luc; Sauter, Daniel

    2013-03-01

    Web Graphics Library (WebGL), the forthcoming web standard for rendering native 3D graphics in a browser, represents an important addition to the biomedical visualization toolset. It is projected to become a mainstream method of delivering 3D online content due to shrinking support for third-party plug-ins. Additionally, it provides a virtual reality (VR) experience to web users accommodated by the growing availability of stereoscopic displays (3D TV, desktop, and mobile). WebGL's value in biomedical visualization has been demonstrated by applications for interactive anatomical models, chemical and molecular visualization, and web-based volume rendering. However, a lack of instructional literature specific to the field prevents many from utilizing this technology. This project defines a WebGL design methodology for a target audience of biomedical artists with a basic understanding of web languages and 3D graphics. The methodology was informed by the development of an interactive web application depicting the anatomy and various pathologies of the human eye. The application supports several modes of stereoscopic displays for a better understanding of 3D anatomical structures.

  4. Real-time auto-stereoscopic visualization of 3D medical images

    NASA Astrophysics Data System (ADS)

    Portoni, Luisa; Patak, Alexandre; Noirard, Pierre; Grossetie, Jean-Claude; van Berkel, Cees

    2000-04-01

    The work here described regards multi-viewer auto- stereoscopic visualization of 3D models of anatomical structures and organs of the human body. High-quality 3D models of more than 1600 anatomical structures have been reconstructed using the Visualization Toolkit, a freely available C++ class library for 3D graphics and visualization. 2D images used for 3D reconstruction comes from the Visible Human Data Set. Auto-stereoscopic 3D image visualization is obtained using a prototype monitor developed at Philips Research Labs, UK. This special multiview 3D-LCD screen has been connected directly to a SGI workstation, where 3D reconstruction and medical imaging applications are executed. Dedicated software has been developed to implement multiview capability. A number of static or animated contemporary views of the same object can simultaneously be seen on the 3D-LCD screen by several observers, having a real 3D perception of the visualized scene without the use of extra media as dedicated glasses or head-mounted displays. Developed software applications allow real-time interaction with visualized 3D models, didactical animations and movies have been realized as well.

  5. Clinically Normal Stereopsis Does Not Ensure a Performance Benefit from Stereoscopic 3D Depth Cues

    NASA Astrophysics Data System (ADS)

    McIntire, John P.; Havig, Paul R.; Harrington, Lawrence K.; Wright, Steve T.; Watamaniuk, Scott N. J.; Heft, Eric L.

    2014-09-01

    To investigate the effect of manipulating disparity on task performance and viewing comfort, twelve participants were tested on a virtual object precision placement task while viewing a stereoscopic 3D (S3D) display. All participants had normal or corrected-to-normal visual acuity, passed the Titmus stereovision clinical test, and demonstrated normal binocular function, including phorias and binocular fusion ranges. Each participant completed six experimental sessions with different maximum binocular disparity limits. The results for ten of the twelve participants were generally as expected, demonstrating a large performance advantage when S3D cues were provided. The sessions with the larger disparity limits typically resulted in the best performance, and the sessions with no S3D cues the poorest performance. However, one participant demonstrated poorer performance in sessions with smaller disparity limits but improved performance in sessions with the larger disparity limits. Another participant's performance declined whenever any S3D cues were provided. Follow-up testing suggested that the phenomenon of pseudo-stereoanomaly may account for one viewer's atypical performance, while the phenomenon of stereoanomaly might account for the other. Overall, the results demonstrate that a subset of viewers with clinically normal binocular and stereoscopic vision may have difficulty performing depth-related tasks on S3D displays. The possibility of the vergence-accommodation conflict contributing to individual performance differences is also discussed.

  6. A stereo matching model observer for stereoscopic viewing of 3D medical images

    NASA Astrophysics Data System (ADS)

    Wen, Gezheng; Markey, Mia K.; Muralidlhar, Gautam S.

    2014-03-01

    Stereoscopic viewing of 3D medical imaging data has the potential to increase the detection of abnormalities. We present a new stereo model observer inspired by the characteristics of stereopsis in human vision. Given a stereo pair of images of an object (i.e., left and right images separated by a small displacement), the model observer rst nds the corresponding points between the two views, and then fuses them together to create a 2D cyclopean view. Assuming that the cyclopean view has extracted most of the 3D information presented in the stereo pair, a channelized Hotelling observer (CHO) can be utilized to make decisions. We conduct a simulation study that attempts to mimic the detection of breast lesions on stereoscopic viewing of breast tomosynthesis projection images. We render voxel datasets that contain random 3D power-law noise to model normal breast tissues with various breast densities. 3D Gaussian signal is added to some of the datasets to model the presence of a breast lesion. By changing the separation angle between the two views, multiple stereo pairs of projection images are generated for each voxel dataset. The performance of the model is evaluated in terms of the accuracy of binary decisions on the presence of the simulated lesions.

  7. Structure light telecentric stereoscopic vision 3D measurement system based on Scheimpflug condition

    NASA Astrophysics Data System (ADS)

    Mei, Qing; Gao, Jian; Lin, Hui; Chen, Yun; Yunbo, He; Wang, Wei; Zhang, Guanjin; Chen, Xin

    2016-11-01

    We designed a new three-dimensional (3D) measurement system for micro components: a structure light telecentric stereoscopic vision 3D measurement system based on the Scheimpflug condition. This system creatively combines the telecentric imaging model and the Scheimpflug condition on the basis of structure light stereoscopic vision, having benefits of a wide measurement range, high accuracy, fast speed, and low price. The system measurement range is 20 mm×13 mm×6 mm, the lateral resolution is 20 μm, and the practical vertical resolution reaches 2.6 μm, which is close to the theoretical value of 2 μm and well satisfies the 3D measurement needs of micro components such as semiconductor devices, photoelectron elements, and micro-electromechanical systems. In this paper, we first introduce the principle and structure of the system and then present the system calibration and 3D reconstruction. We then present an experiment that was performed for the 3D reconstruction of the surface topography of a wafer, followed by a discussion. Finally, the conclusions are presented.

  8. Quality assessment of stereoscopic 3D image compression by binocular integration behaviors.

    PubMed

    Lin, Yu-Hsun; Wu, Ja-Ling

    2014-04-01

    The objective approaches of 3D image quality assessment play a key role for the development of compression standards and various 3D multimedia applications. The quality assessment of 3D images faces more new challenges, such as asymmetric stereo compression, depth perception, and virtual view synthesis, than its 2D counterparts. In addition, the widely used 2D image quality metrics (e.g., PSNR and SSIM) cannot be directly applied to deal with these newly introduced challenges. This statement can be verified by the low correlation between the computed objective measures and the subjectively measured mean opinion scores (MOSs), when 3D images are the tested targets. In order to meet these newly introduced challenges, in this paper, besides traditional 2D image metrics, the binocular integration behaviors-the binocular combination and the binocular frequency integration, are utilized as the bases for measuring the quality of stereoscopic 3D images. The effectiveness of the proposed metrics is verified by conducting subjective evaluations on publicly available stereoscopic image databases. Experimental results show that significant consistency could be reached between the measured MOS and the proposed metrics, in which the correlation coefficient between them can go up to 0.88. Furthermore, we found that the proposed metrics can also address the quality assessment of the synthesized color-plus-depth 3D images well. Therefore, it is our belief that the binocular integration behaviors are important factors in the development of objective quality assessment for 3D images.

  9. 3-D Flow Field Diagnostics and Validation Studies using Stereoscopic Tracking Velocimetry

    NASA Technical Reports Server (NTRS)

    Cha, Soyoung Stephen; Ramachandran, Narayanan; Whitaker, Ann F. (Technical Monitor)

    2002-01-01

    The measurement of 3-D three-component velocity fields is of great importance in both ground and space experiments for understanding materials processing and fluid physics. Here, we present the investigation results of stereoscopic tracking velocimetry (STV) for measuring 3-D velocity fields. The effort includes diagnostic technology development, experimental velocity measurement, and comparison with analytical and numerical computation. The advantages of STV stems from the system simplicity for building compact hardware and in software efficiency for continual near-real-time process monitoring. It also has illumination flexibility for observing volumetric flow fields from arbitrary directions. STV is based on stereoscopic CCD observations of particles seeded in a flow. Neural networks are used for data analysis. The developed diagnostic tool is tested with a simple directional solidification apparatus using Succinonitrile. The 3-D velocity field in the liquid phase is measured and compared with results from detailed numerical computations. Our theoretical, numerical, and experimental effort has shown STV to be a viable candidate for reliably quantifying the 3-D flow field in materials processing and fluids experiments.

  10. Binocular depth acuity research to support the modular multi-spectral stereoscopic night vision goggle

    NASA Astrophysics Data System (ADS)

    Merritt, John O.; CuQlock-Knopp, V. Grayson; Paicopolis, Peter; Smoot, Jennifer; Kregel, Mark; Corona, Bernard

    2006-05-01

    This paper discusses the depth acuity research conducted in support of the development of a Modular Multi-Spectral Stereoscopic (M2S2) night vision goggle (NVG), a customizable goggle that lets the user select one of five goggle configurations: monocular thermal, monocular image intensifier (I2), binocular I2, binocular thermal, and binocular dual-waveband (thermal imagery to one eye and I2 imagery to the other eye). The motives for the development of this type of customizable goggle were (1) the need for an NVG that allows the simultaneous use of two wavebands, (2) the need for an alternative sensor fusion method to avoid the potential image degradation that may accompany digitally fused images, (3) a requirement to provide the observer with stereoscopic, dual spectrum views of a scene, and (4) the need to handle individual user preferences for sensor types and ocular configurations employed in various military operations. Among the increases in functionality that the user will have with this system is the ability to convert from a binocular I2 device (needed for detailed terrain analysis during off-road mobility) to a monocular thermal device (for increased situational awareness in the unaided eye during nights with full moon illumination). Results of the present research revealed potential depth acuity advantages that may apply to off-road terrain hazard detection for the binocular thermal configuration. The results also indicated that additional studies are needed to address ways to minimize binocular incompatibility for the dual waveband configuration.

  11. The design and implementation of stereoscopic 3D scalable vector graphics based on WebKit

    NASA Astrophysics Data System (ADS)

    Liu, Zhongxin; Wang, Wenmin; Wang, Ronggang

    2014-03-01

    Scalable Vector Graphics (SVG), which is a language designed based on eXtensible Markup Language (XML), is used to describe basic shapes embedded in webpages, such as circles and rectangles. However, it can only depict 2D shapes. As a consequence, web pages using classical SVG can only display 2D shapes on a screen. With the increasing development of stereoscopic 3D (S3D) technology, binocular 3D devices have been widely used. Under this circumstance, we intend to extend the widely used web rendering engine WebKit to support the description and display of S3D webpages. Therefore, the extension of SVG is of necessity. In this paper, we will describe how to design and implement SVG shapes with stereoscopic 3D mode. Two attributes representing the depth and thickness are added to support S3D shapes. The elimination of hidden lines and hidden surfaces, which is an important process in this project, is described as well. The modification of WebKit is also discussed, which is made to support the generation of both left view and right view at the same time. As is shown in the result, in contrast to the 2D shapes generated by the Google Chrome web browser, the shapes got from our modified browser are in S3D mode. With the feeling of depth and thickness, the shapes seem to be real 3D objects away from the screen, rather than simple curves and lines as before.

  12. A novel autostereoscopic display system to provide seamless stereoscopic view changes

    NASA Astrophysics Data System (ADS)

    Lee, Hyun; Um, Gi-Mun; Cheong, Won-Sik; Hur, Namho; Lee, Sung Jung; Kim, Changick

    2011-09-01

    In this paper a new method for the autostereoscopic display, named the Dual Layer Parallax Barrier (DLPB) method, is introduced to overcome the limitation of the fixed viewing zone. Compared with the conventional parallax barrier methods, the proposed DLPB method uses moving parallax barriers to make the stereoscopic view changed according to the movement of viewer. In addition it provides seamless stereoscopic views without abrupt change of 3D depth feeling at any eye position. We implement a prototype of the DLPB system which consists of a switchable dual-layered Twisted Nematic Liquid Crystal Display (TN-LCD) and a head-tracker. The head tracker employs a video camera for capturing images, and is used to calculate the angle between the eye gazing direction and the projected direction onto the display plane. According to the head-tracker's control signal, the dual-layered TN-LCD is able to alternate the direction of viewing zone adaptively by a solid-state analog switch. The experimental results demonstrate that the proposed autostereoscopic display maintains seamless 3D views even when a viewer's head is moving. Moreover, its extended use towards mobile devices such as portable multimedia player (PMP), smartphone, and cellular phone is discussed as well.

  13. Toward a Blind Deep Quality Evaluator for Stereoscopic Images Based on Monocular and Binocular Interactions.

    PubMed

    Shao, Feng; Tian, Weijun; Lin, Weisi; Jiang, Gangyi; Dai, Qionghai

    2016-05-01

    During recent years, blind image quality assessment (BIQA) has been intensively studied with different machine learning tools. Existing BIQA metrics, however, do not design for stereoscopic images. We believe this problem can be resolved by separating 3D images and capturing the essential attributes of images via deep neural network. In this paper, we propose a blind deep quality evaluator (DQE) for stereoscopic images (denoted by 3D-DQE) based on monocular and binocular interactions. The key technical steps in the proposed 3D-DQE are to train two separate 2D deep neural networks (2D-DNNs) from 2D monocular images and cyclopean images to model the process of monocular and binocular quality predictions, and combine the measured 2D monocular and cyclopean quality scores using different weighting schemes. Experimental results on four public 3D image quality assessment databases demonstrate that in comparison with the existing methods, the devised algorithm achieves high consistent alignment with subjective assessment. PMID:26960225

  14. Stereoscopic Analysis of 19 May and 31 Aug 2007 Filament Eruptions

    NASA Technical Reports Server (NTRS)

    Liewer, Paulett; DeJong, E. M.; Hall, J. R.

    2008-01-01

    The presentation outline includes results from stereoscopic analysis of SECCHI/EUVI data for 19 May 2007 filament eruption, including the determined 3D trajectory of erupting filament, strong evidence for reconnection below erupting filament as consistent with standard model, and comparison of EUVI and H-alpha images during eruption; and results from stereoscopic analytic of 21 August 2007 filament eruption. Slide topics include standard model of filament eruption; 2007 May 19 STEREO A/SECCHI/EUVI 195 and 304 A: CME signatures and filament eruption, 3D reconstruction of erupting prominence; filament's relation to coronal magnetic fields; 3d reconstructions of filament eruption; height-time plot of eruption from 3D reconstructions; detailed pre-eruptions comparison of H-alpha and EUVI 304 at 12:42 UT; comparisons during the eruption; STEREO prominence and CME August 31, 2007; reconstructions of prominence and leading edges of both dark cavity and CME; and 3D reconstructions of prominence and leading edges.

  15. Matching methods evaluation framework for stereoscopic breast x-ray images.

    PubMed

    Rousson, Johanna; Naudin, Mathieu; Marchessoux, Cédric

    2016-01-01

    Three-dimensional (3-D) imaging has been intensively studied in the past few decades. Depth information is an important added value of 3-D systems over two-dimensional systems. Special focuses were devoted to the development of stereo matching methods for the generation of disparity maps (i.e., depth information within a 3-D scene). Dedicated frameworks were designed to evaluate and rank the performance of different stereo matching methods but never considering x-ray medical images. Yet, 3-D x-ray acquisition systems and 3-D medical displays have already been introduced into the diagnostic market. To access the depth information within x-ray stereoscopic images, computing accurate disparity maps is essential. We aimed at developing a framework dedicated to x-ray stereoscopic breast images used to evaluate and rank several stereo matching methods. A multiresolution pyramid optimization approach was integrated to the framework to increase the accuracy and the efficiency of the stereo matching techniques. Finally, a metric was designed to score the results of the stereo matching compared with the ground truth. Eight methods were evaluated and four of them [locally scaled sum of absolute differences (LSAD), zero mean sum of absolute differences, zero mean sum of squared differences, and locally scaled mean sum of squared differences] appeared to perform equally good with an average error score of 0.04 (0 is the perfect matching). LSAD was selected for generating the disparity maps. PMID:26587552

  16. Stereoscopic Analysis of the 31 August 2007 Prominence Eruption and Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Liewer, P. C.; Panasenco, O.; Hall, J. R.

    2013-01-01

    The spectacular prominence eruption and CME of 31 August 2007 are analyzed stereoscopically using data from NASA's twin Solar Terrestrial Relations Observatory (STEREO) spacecraft. The technique of tie pointing and triangulation (T&T) is used to reconstruct the prominence (or filament when seen on the disk) before and during the eruption. For the first time, a filament barb is reconstructed in three-dimensions, confirming that the barb connects the filament spine to the solar surface. The chirality of the filament system is determined from the barb and magnetogram and confirmed by the skew of the loops of the post-eruptive arcade relative to the polarity reversal boundary below. The T&T analysis shows that the filament rotates as it erupts in the direction expected for a filament system of the given chirality. While the prominence begins to rotate in the slow-rise phase, most of the rotation occurs during the fast-rise phase, after formation of the CME begins. The stereoscopic analysis also allows us to analyze the spatial relationships among various features of the eruption including the pre-eruptive filament, the flare ribbons, the erupting prominence, and the cavity of the coronal mass ejection (CME). We find that erupting prominence strands and the CME have different (non-radial) trajectories; we relate the trajectories to the structure of the coronal magnetic fields. The possible cause of the eruption is also discussed.

  17. Optoelectronic stereoscopic device for diagnostics, treatment, and developing of binocular vision

    NASA Astrophysics Data System (ADS)

    Pautova, Larisa; Elkhov, Victor A.; Ovechkis, Yuri N.

    2003-08-01

    Operation of the device is based on alternative generation of pictures for left and right eyes on the monitor screen. Controller gives pulses on LCG so that shutter for left or right eye opens synchronously with pictures. The device provides frequency of switching more than 100 Hz, and that is why the flickering is absent. Thus, a separate demonstration of images to the left eye or to the right one in turn is obtained for patients being unaware and creates the conditions of binocular perception clsoe to natural ones without any additional separation of vision fields. LC-cell transfer characteristic coodination with time parameters of monitor screen has enabled to improve stereo image quality. Complicated problem of computer stereo images with LC-glasses is so called 'ghosts' - noise images that come to blocked eye. We reduced its influence by adapting stereo images to phosphor and LC-cells characteristics. The device is intended for diagnostics and treatment of stabismus, amblyopia and other binocular and stereoscopic vision impairments, for cultivating, training and developing of stereoscopic vision, for measurements of horizontal and vertical phoria, phusion reserves, the stereovision acuity and some else, for fixing central scotoma borders, as well as suppression scotoma in strabismus too.

  18. Toward virtual anatomy: a stereoscopic 3-D interactive multimedia computer program for cranial osteology.

    PubMed

    Trelease, R B

    1996-01-01

    Advances in computer visualization and user interface technologies have enabled development of "virtual reality" programs that allow users to perceive and to interact with objects in artificial three-dimensional environments. Such technologies were used to create an image database and program for studying the human skull, a specimen that has become increasingly expensive and scarce. Stereoscopic image pairs of a museum-quality skull were digitized from multiple views. For each view, the stereo pairs were interlaced into a single, field-sequential stereoscopic picture using an image processing program. The resulting interlaced image files are organized in an interactive multimedia program. At run-time, gray-scale 3-D images are displayed on a large-screen computer monitor and observed through liquid-crystal shutter goggles. Users can then control the program and change views with a mouse and cursor to point-and-click on screen-level control words ("buttons"). For each view of the skull, an ID control button can be used to overlay pointers and captions for important structures. Pointing and clicking on "hidden buttons" overlying certain structures triggers digitized audio spoken word descriptions or mini lectures.

  19. A foreground object features-based stereoscopic image visual comfort assessment model

    NASA Astrophysics Data System (ADS)

    Jin, Xin; Jiang, G.; Ying, H.; Yu, M.; Ding, S.; Peng, Z.; Shao, F.

    2014-11-01

    Since stereoscopic images provide observers with both realistic and discomfort viewing experience, it is necessary to investigate the determinants of visual discomfort. By considering that foreground object draws most attention when human observing stereoscopic images. This paper proposes a new foreground object based visual comfort assessment (VCA) metric. In the first place, a suitable segmentation method is applied to disparity map and then the foreground object is ascertained as the one having the biggest average disparity. In the second place, three visual features being average disparity, average width and spatial complexity of foreground object are computed from the perspective of visual attention. Nevertheless, object's width and complexity do not consistently influence the perception of visual comfort in comparison with disparity. In accordance with this psychological phenomenon, we divide the whole images into four categories on the basis of different disparity and width, and exert four different models to more precisely predict its visual comfort in the third place. Experimental results show that the proposed VCA metric outperformance other existing metrics and can achieve a high consistency between objective and subjective visual comfort scores. The Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are over 0.84 and 0.82, respectively.

  20. Optical Coherence Tomography

    MedlinePlus

    ... Cardiac Magnetic Resonance Imaging (MRI and MRA) Computed Tomography (CT) Scan Diagnostic Tests and Procedures Echocardiography Electrocardiogram ... Ultrasound Nuclear Stress Test Nuclear Ventriculography Positron Emission Tomography (PET) Stress ... Optical Coherence Tomography | ...

  1. Optimal evolution models for quantum tomography

    NASA Astrophysics Data System (ADS)

    Czerwiński, Artur

    2016-02-01

    The research presented in this article concerns the stroboscopic approach to quantum tomography, which is an area of science where quantum physics and linear algebra overlap. In this article we introduce the algebraic structure of the parametric-dependent quantum channels for 2-level and 3-level systems such that the generator of evolution corresponding with the Kraus operators has no degenerate eigenvalues. In such cases the index of cyclicity of the generator is equal to 1, which physically means that there exists one observable the measurement of which performed a sufficient number of times at distinct instants provides enough data to reconstruct the initial density matrix and, consequently, the trajectory of the state. The necessary conditions for the parameters and relations between them are introduced. The results presented in this paper seem to have considerable potential applications in experiments due to the fact that one can perform quantum tomography by conducting only one kind of measurement. Therefore, the analyzed evolution models can be considered optimal in the context of quantum tomography. Finally, we introduce some remarks concerning optimal evolution models in the case of n-dimensional Hilbert space.

  2. Looking White and Middle-Class: Stereoscopic Imagery and Technology in the Early Twentieth-Century United States

    ERIC Educational Resources Information Center

    Malin, Brenton J.

    2007-01-01

    This essay explores a series of discourses surrounding the images of the early twentieth-century stereoscope, focusing on Underwood & Underwood of Ottawa, Kansas, and the Keystone View Company, of Meadville, Pennsylvania. By publishing images of particular geographic areas and historical events, as well as compendium volumes that included…

  3. The Influence of Manifest Strabismus and Stereoscopic Vision on Non-Verbal Abilities of Visually Impaired Children

    ERIC Educational Resources Information Center

    Gligorovic, Milica; Vucinic, Vesna; Eskirovic, Branka; Jablan, Branka

    2011-01-01

    This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest…

  4. Anaglyphic three-dimensional stereoscopic printing: revival of an old method for anatomical and surgical teaching and reporting.

    PubMed

    Ribas, G C; Bento, R F; Rodrigues, A J

    2001-12-01

    The authors describe how to use the three-dimensional (3D) anaglyphic method to produce stereoscopic prints for anatomical and surgical teaching and reports preparation by using currently available nonprofessional photographic and computer methods. As with any other method of producing stereoscopic images, the anaglyphic procedure is based on the superimposition of two slightly different images of the object to be reproduced, one seen more from a left-sided point of view and the other seen more from a right-sided point of view. The pictures are obtained using a single camera, which following the first shot can be slid along a special bar for the second shot, or by using two cameras affixed to a surgical microscope. After the images have been distinguished from each other by applying different complementary color dyes, the images are scanned and superimposed on each other with the aid of nonprofessional imaging-manipulation software used on a standard personal computer (PC), and are printed using a standard printer. To be seen stereoscopically, glasses with colored lenses, normally one red and one blue, have to be used. Stereoscopic 3D anaglyphic prints can be produced using standard photographic and PC equipment; after some training, the prints can be easily reproduced without significant cost and are particularly helpful to disclose the 3D character of anatomical structures.

  5. Comparing Short- and Long-Term Learning Effects between Stereoscopic and Two-Dimensional Film at a Planetarium

    ERIC Educational Resources Information Center

    Price, C. Aaron; Lee, Hee-Sun; Subbarao, Mark; Kasal, Evan; Aguileara, Julieta

    2015-01-01

    Science centers such as museums and planetariums have used stereoscopic ("three-dimensional") films to draw interest from and educate their visitors for decades. Despite the fact that most adults who are finished with their formal education get their science knowledge from such free-choice learning settings very little is known about the…

  6. The Effect of Two-Dimensional and Stereoscopic Presentation on Middle School Students' Performance of Spatial Cognition Tasks

    ERIC Educational Resources Information Center

    Price, Aaron; Lee, Hee-Sun

    2010-01-01

    We investigated whether and how student performance on three types of spatial cognition tasks differs when worked with two-dimensional or stereoscopic representations. We recruited nineteen middle school students visiting a planetarium in a large Midwestern American city and analyzed their performance on a series of spatial cognition tasks in…

  7. Windows Instant Messaging App Forensics: Facebook and Skype as Case Studies.

    PubMed

    Yang, Teing Yee; Dehghantanha, Ali; Choo, Kim-Kwang Raymond; Muda, Zaiton

    2016-01-01

    Instant messaging (IM) has changed the way people communicate with each other. However, the interactive and instant nature of these applications (apps) made them an attractive choice for malicious cyber activities such as phishing. The forensic examination of IM apps for modern Windows 8.1 (or later) has been largely unexplored, as the platform is relatively new. In this paper, we seek to determine the data remnants from the use of two popular Windows Store application software for instant messaging, namely Facebook and Skype on a Windows 8.1 client machine. This research contributes to an in-depth understanding of the types of terrestrial artefacts that are likely to remain after the use of instant messaging services and application software on a contemporary Windows operating system. Potential artefacts detected during the research include data relating to the installation or uninstallation of the instant messaging application software, log-in and log-off information, contact lists, conversations, and transferred files. PMID:26982207

  8. Windows Instant Messaging App Forensics: Facebook and Skype as Case Studies

    PubMed Central

    Yang, Teing Yee; Dehghantanha, Ali; Choo, Kim-Kwang Raymond; Muda, Zaiton

    2016-01-01

    Instant messaging (IM) has changed the way people communicate with each other. However, the interactive and instant nature of these applications (apps) made them an attractive choice for malicious cyber activities such as phishing. The forensic examination of IM apps for modern Windows 8.1 (or later) has been largely unexplored, as the platform is relatively new. In this paper, we seek to determine the data remnants from the use of two popular Windows Store application software for instant messaging, namely Facebook and Skype on a Windows 8.1 client machine. This research contributes to an in-depth understanding of the types of terrestrial artefacts that are likely to remain after the use of instant messaging services and application software on a contemporary Windows operating system. Potential artefacts detected during the research include data relating to the installation or uninstallation of the instant messaging application software, log-in and log-off information, contact lists, conversations, and transferred files. PMID:26982207

  9. Volatile compounds and sensory characteristics of various instant teas produced from black tea.

    PubMed

    Kraujalytė, Vilma; Pelvan, Ebru; Alasalvar, Cesarettin

    2016-03-01

    Various instant teas produced differently from black tea [freeze-dried instant tea (FDIT), spray-dried instant tea (SDIT), and decaffeinated instant tea (DCIT)], were compared for their differences in volatile compounds as well as descriptive sensory analysis (DSA). A total of 63 volatile compounds in all tea samples (eight aldehydes, ten alcohols, nine ketones, five esters, eight acids, ten terpenes/terpenoids, ten furans/furanones, two pyrroles, and one miscellaneous compound) were tentatively identified. Black tea, FDIT, SDIT, and DCIT contained 60, 55, 47, and 40 volatile compounds, respectively. Ten flavour attributes such as after taste, astringency, bitter, caramel-like, floral/sweet, green/grassy, hay-like, malty, roasty, and seaweed were identified. Intensities for a number of flavour attributes (except for caramel-like in SDIT and bitter and after taste in DCIT) were not significantly different (p>0.05) among tea samples. The present study suggests that instant teas can also be used as good alternative to black tea.

  10. Three-Dimensional Stereoscopic Tracking Velocimetry and Experimental/Numerical Comparison of Directional Solidification

    NASA Technical Reports Server (NTRS)

    Lee, David; Ge, Yi; Cha, Soyoung Stephen; Ramachandran, Narayanan; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Measurement of three-dimensional (3-D) three-component velocity fields is of great importance in both ground and space experiments for understanding materials processing and fluid physics. The experiments in these fields most likely inhibit the application of conventional planar probes for observing 3-D phenomena. Here, we present the investigation results of stereoscopic tracking velocimetry (STV) for measuring 3-D velocity fields, which include diagnostic technology development, experimental velocity measurement, and comparison with analytical and numerical computation. STV is advantageous in system simplicity for building compact hardware and in software efficiency for continual near-real-time monitoring. It has great freedom in illuminating and observing volumetric fields from arbitrary directions. STV is based on stereoscopic observation of particles-Seeded in a flow by CCD sensors. In the approach, part of the individual particle images that provide data points is likely to be lost or cause errors when their images overlap and crisscross each other especially under a high particle density. In order to maximize the valid recovery of data points, neural networks are implemented for these two important processes. For the step of particle overlap decomposition, the back propagation neural network is utilized because of its ability in pattern recognition with pertinent particle image feature parameters. For the step of particle tracking, the Hopfield neural network is employed to find appropriate particle tracks based on global optimization. Our investigation indicates that the neural networks are very efficient and useful for stereoscopically tracking particles. As an initial assessment of the diagnostic technology performance, laminar water jets with and without pulsation are measured. The jet tip velocity profiles are in good agreement with analytical predictions. Finally, for testing in material processing applications, a simple directional solidification

  11. Demonstration of color constancy in photographs by two techniques: Stereoscope and D-up viewer

    NASA Astrophysics Data System (ADS)

    Phuangsuwan, Chanprapha; Ikeda, Mitsuo; Shinoda, Hiroyuki

    2014-11-01

    When we look, under daylight, at a scene in a photograph taken under an incandescent lamp, it appears very reddish, showing that color constancy is not maintained. According to the recognized visual space of illumination (RVSI) concept, color constancy should exist in a photograph if one can perceive three dimensions in it. This prediction was confirmed by applying two viewing techniques to perceive a 3D space in a 2D photograph: a stereoscope viewed with two eyes and a D-up viewer viewed with one eye. A wide range of illumination color was investigated, covering range from vivid blue through to vivid orange, and the color constancy index became larger with the 3D perception than with the 2D perception of the photographs produced by the two techniques.

  12. Stereoscopic PIV measurements of flow in the nasal cavity with high flow therapy

    NASA Astrophysics Data System (ADS)

    Spence, C. J. T.; Buchmann, N. A.; Jermy, M. C.; Moore, S. M.

    2011-04-01

    Knowledge of the airflow characteristics within the nasal cavity with nasal high flow (NHF) therapy and during unassisted breathing is essential to understand the treatment's efficacy. The distribution and velocity of the airflow in the nasal cavity with and without NHF cannula flow has been investigated using stereoscopic particle image velocimetry at steady peak expiration and inspiration. In vivo breathing flows were measured and dimensionally scaled to reproduce physiological conditions in vitro. A scaled model of the complete nasal cavity was constructed in transparent silicone and airflow simulated with an aqueous glycerine solution. NHF modifies nasal cavity flow patterns significantly, altering the proportion of inspiration and expiration through each passageway and producing jets with in vivo velocities up to 17.0 ms-1 for 30 l/min cannula flow. Velocity magnitudes differed appreciably between the left and right sides of the nasal cavity. The importance of using a three-component measurement technique when investigating nasal flows has been highlighted.

  13. 3-Component acceleration field measurement by dual-time stereoscopic particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Perret, L.; Braud, P.; Fourment, C.; David, L.; Delville, J.

    2006-05-01

    In this article, a multiplane stereo-particle image velocimetry (PIV) system was implemented and validated to measure the three-component acceleration field in a plane of turbulent flows. The employed technique relies on the use of two stereoscopic particle image velocimetry (SPIV) systems to measure pairs of velocity fields superimposed in space but shifted in time. The time delay between the two velocity fields enables the implementation of a finite difference scheme to compute temporal derivatives. The use of two synchronized SPIV systems allows us to overcome the limited acquisition rate of PIV systems when dealing with highly turbulent flows. Moreover, a methodology based on the analysis of the spectral error distribution is described here to determine the optimal time delay to compute time derivatives. The present dual-time SPIV arrangement and the proposed analysis method are applied to measure three-component acceleration fields in a cross section of a subsonic plane turbulent mixing layer.

  14. What factors are related to understanding a stereoscopic 3D diabetes educational video in seniors?

    PubMed

    Liu, Chiung-ju; William, Albert

    2014-10-01

    The rise of three-dimensional imaging technology and products offers a new avenue for patient education to older adults. This study investigated older adults' perception of a three-dimensional health education video on diabetes, and factors associated with understanding the video. Twenty-one older adults without a history of diabetes watched a short diabetes educational video on a stereoscopic display. They perceived the video as helpful, valuable, and exciting, but too fast. Better understanding of the video is associated with having higher background knowledge of diabetes and greater vocabulary. Ethnicity is also a potential factor. Older adults may choose narrative information over graphic information to process a three-dimensional multimedia presentation.

  15. 3D ultrasound to stereoscopic camera registration through an air-tissue boundary.

    PubMed

    Yip, Michael C; Adebar, Troy K; Rohling, Robert N; Salcudean, Septimiu E; Nguan, Christopher Y

    2010-01-01

    A novel registration method between 3D ultrasound and stereoscopic cameras is proposed based on tracking a registration tool featuring both ultrasound fiducials and optical markers. The registration tool is pressed against an air-tissue boundary where it can be seen both in ultrasound and in the camera view. By localizing the fiducials in the ultrasound volume, knowing the registration tool geometry, and tracking the tool with the cameras, a registration is found. This method eliminates the need for external tracking, requires minimal setup, and may be suitable for a range of minimally invasive surgeries. A study of the appearance of ultrasound fiducials on an air-tissue boundary is presented, and an initial assessment of the ability to localize the fiducials in ultrasound with sub-millimeter accuracy is provided. The overall accuracy of registration (1.69 +/- 0.60 mm) is a noticeable improvement over other reported methods and warrants patient studies.

  16. Double large field stereoscopic PIV in a high Reynolds number turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Coudert, S.; Foucaut, J. M.; Kostas, J.; Stanislas, M.; Braud, P.; Fourment, C.; Delville, J.; Tutkun, M.; Mehdi, F.; Johansson, P.; George, W. K.

    2011-01-01

    An experiment on a flat plate turbulent boundary layer at high Reynolds number has been carried out in the Laboratoire de Mecanique de Lille (LML, UMR CNRS 8107) wind tunnel. This experiment was performed jointly with LEA (UMR CNRS 6609) in Poitiers (France) and Chalmers University of Technology (Sweden), in the frame of the WALLTURB European project. The simultaneous recording of 143 hot wires in one transverse plane and of two perpendicular stereoscopic PIV fields was performed successfully. The first SPIV plane is 1 cm upstream of the hot wire rake and the second is both orthogonal to the first one and to the wall. The first PIV results show a blockage effect which based on both statistical results (i.e. mean, RMS and spatial correlation) and a potential model does not seem to affect the turbulence organization.

  17. Remote stereoscopic video play platform for naked eyes based on the Android system

    NASA Astrophysics Data System (ADS)

    Jia, Changxin; Sang, Xinzhu; Liu, Jing; Cheng, Mingsheng

    2014-11-01

    As people's life quality have been improved significantly, the traditional 2D video technology can not meet people's urgent desire for a better video quality, which leads to the rapid development of 3D video technology. Simultaneously people want to watch 3D video in portable devices,. For achieving the above purpose, we set up a remote stereoscopic video play platform. The platform consists of a server and clients. The server is used for transmission of different formats of video and the client is responsible for receiving remote video for the next decoding and pixel restructuring. We utilize and improve Live555 as video transmission server. Live555 is a cross-platform open source project which provides solutions for streaming media such as RTSP protocol and supports transmission of multiple video formats. At the receiving end, we use our laboratory own player. The player for Android, which is with all the basic functions as the ordinary players do and able to play normal 2D video, is the basic structure for redevelopment. Also RTSP is implemented into this structure for telecommunication. In order to achieve stereoscopic display, we need to make pixel rearrangement in this player's decoding part. The decoding part is the local code which JNI interface calls so that we can extract video frames more effectively. The video formats that we process are left and right, up and down and nine grids. In the design and development, a large number of key technologies from Android application development have been employed, including a variety of wireless transmission, pixel restructuring and JNI call. By employing these key technologies, the design plan has been finally completed. After some updates and optimizations, the video player can play remote 3D video well anytime and anywhere and meet people's requirement.

  18. [Light and temperature and their effects on photosynthesis characteristics of stereoscopic cultivation in Panax notoginseng].

    PubMed

    Wang, Yao-long; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Li, Rui-bo; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Light intensity, gas temperature, soil temperature and gas exchange parameters were determined of three years old Panax notoginseng planted on different layers seedbed and different location (left, middle, right) of the same layer in greenhouse. Result show that diurnal variation of light intensity, gas temperature and soil temperature showed that upper layer > middle layer > lower layer; different locations of the same layer showed that light intensity of upper layer was not different among different locations; light intensity of middle and lower layer in right and left were the same, and significantly higher than those in the middle position; the gas temperature of each layer all with less different of each location; soil temperature of 12 cm depth is the lowest, and was gradually increased to the upper and lower surface; net photosynthetic efficiency of P. notoginseng showed that upper layer > middle layer > lower layer; there were significant correlation between soil temperature, stomatal conductance, intercellular CO2 concentration and photosynthetic rate were correlated with light intensity significantly; transpiration rates had notable correlation with light intensity and gas temperature. All above indicated that net photosynthesis rate of P. notoginseng was affected by light intensity directly, gas temperature and soil temperature indirectly. Inconclusion, stereoscopic cultivation of P. notoginseng was practicable in present study. The planting quality of P. notoginseng under stereoscopic cultivation could be improved by ameliorate the structure of seedbed to enhance the light intensity of middle and lower layer. Increase the thickness of the seedbed to decrease the temperature difference of soil. Further the management of ventilation facilities of greenhouse to control the gas temperature. PMID:26677688

  19. [Light and temperature and their effects on photosynthesis characteristics of stereoscopic cultivation in Panax notoginseng].

    PubMed

    Wang, Yao-long; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Li, Rui-bo; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Light intensity, gas temperature, soil temperature and gas exchange parameters were determined of three years old Panax notoginseng planted on different layers seedbed and different location (left, middle, right) of the same layer in greenhouse. Result show that diurnal variation of light intensity, gas temperature and soil temperature showed that upper layer > middle layer > lower layer; different locations of the same layer showed that light intensity of upper layer was not different among different locations; light intensity of middle and lower layer in right and left were the same, and significantly higher than those in the middle position; the gas temperature of each layer all with less different of each location; soil temperature of 12 cm depth is the lowest, and was gradually increased to the upper and lower surface; net photosynthetic efficiency of P. notoginseng showed that upper layer > middle layer > lower layer; there were significant correlation between soil temperature, stomatal conductance, intercellular CO2 concentration and photosynthetic rate were correlated with light intensity significantly; transpiration rates had notable correlation with light intensity and gas temperature. All above indicated that net photosynthesis rate of P. notoginseng was affected by light intensity directly, gas temperature and soil temperature indirectly. Inconclusion, stereoscopic cultivation of P. notoginseng was practicable in present study. The planting quality of P. notoginseng under stereoscopic cultivation could be improved by ameliorate the structure of seedbed to enhance the light intensity of middle and lower layer. Increase the thickness of the seedbed to decrease the temperature difference of soil. Further the management of ventilation facilities of greenhouse to control the gas temperature.

  20. Stereoscopic Planar Laser-Induced Fluorescence Imaging at 500 kHz

    NASA Technical Reports Server (NTRS)

    Medford, Taylor L.; Danehy, Paul M.; Jones, Stephen B.; Jiang, N.; Webster, M.; Lempert, Walter; Miller, J.; Meyer, T.

    2011-01-01

    A new measurement technique for obtaining time- and spatially-resolved image sequences in hypersonic flows is developed. Nitric-oxide planar laser-induced fluorescence (NO PLIF) has previously been used to investigate transition from laminar to turbulent flow in hypersonic boundary layers using both planar and volumetric imaging capabilities. Low flow rates of NO were typically seeded into the flow, minimally perturbing the flow. The volumetric imaging was performed at a measurement rate of 10 Hz using a thick planar laser sheet that excited NO fluorescence. The fluorescence was captured by a pair of cameras having slightly different views of the flow. Subsequent stereoscopic reconstruction of these images allowed the three-dimensional flow structures to be viewed. In the current paper, this approach has been extended to 50,000 times higher repetition rates. A laser operating at 500 kHz excites the seeded NO molecules, and a camera, synchronized with the laser and fitted with a beam-splitting assembly, acquires two separate images of the flow. The resulting stereoscopic images provide three-dimensional flow visualizations at 500 kHz for the first time. The 200 ns exposure time in each frame is fast enough to freeze the flow while the 500 kHz repetition rate is fast enough to time-resolve changes in the flow being studied. This method is applied to visualize the evolving hypersonic flow structures that propagate downstream of a discrete protuberance attached to a flat plate. The technique was demonstrated in the NASA Langley Research Center s 31-Inch Mach 10 Air Tunnel facility. Different tunnel Reynolds number conditions, NO flow rates and two different cylindrical protuberance heights were investigated. The location of the onset of flow unsteadiness, an indicator of transition, was observed to move downstream during the tunnel runs, coinciding with an increase in the model temperature.

  1. An evaluation of instant and regular coffee in the Ames mutagenicity test.

    PubMed

    Aeschbacher, H U; Würzner, H P

    1980-02-01

    High concentrations of "home brew" and instant coffe induced revertants 2--3-fold the spontaneous level with the Ames Salmonella tester strain TA 100 but not with the strains TA 98, TA 1535, TA 1537 and TA 1538. This borderline effect, which may also have been due to non-mutagenic interactions (false positives) occurred only at bacterial levels of coffees and was completely abolished in the presence of the microsomal "metabolic activation system". Negative results were obtained in host-mediated assays when mice received up to 6 g instant coffee/kg body weight. An extrapolation in respect of possible carcinogenic risks is dubious. PMID:7008262

  2. Characterization of mutagenic activity in grain-based coffee-substitute blends and instant coffees

    SciTech Connect

    Johansson, M.A.E.; Knize, M.G.; Felton, J.S.; Jagerstad, M.

    1994-06-01

    Several grain-based coffee-substitute blends and instant coffees showed a mutagenic response in the Ames/Salmonella test using TA98, YG1024 and YG1O29 with metabolic activation. The beverage powders contained 150 to 500 TA98 and 1150 to 4050 YG1024 revertant colonies/gram, respectively. The mutagenic activity in the beverage powders was shown to be stable to heat and the products varied in resistance to acid nitrite treatment. Characterization of the mutagenic activity, using HPLC-and the Ames test of the collected fractions, showed the coffee-substitutes and instant coffees contain several mutagenic compounds, which are most likely aromatic amines.

  3. Photoacoustic Tomography

    NASA Astrophysics Data System (ADS)

    Wang, Lihong V.

    Photoacoustic tomography (PAT) refers to imaging that is based on the photoacoustic effect. Although the photoacoustic effect as a physical phenomenon was first reported on by Alexander Graham Bell in 1880 [1], PAT as an imaging technology was developed only after the advent of ultrasonic transducers, computers, and lasers [2-31]. A review on biomedical photoacoustics is available [32]. The motivation for PAT is to combine optical-absorption contrast with ultrasonic spatial resolution for deep imaging in the optical quasi-diffusive or diffusive regime. In PAT, the tissue is irradiated by usually a short-pulsed laser beam to achieve a thermal and acoustic impulse response (Fig. 19.1). Locally absorbed light is converted into heat, which is further converted to a pressure rise via thermo-elastic expansion. The initial pressure rise - determined by the local optical absorption coefficient (μ â ), fluence (ψ) and other thermal and mechanical properties - propagates as an ultrasonic wave, which is referred to as a photoacoustic wave.

  4. 40 CFR 723.175 - Chemical substances used in or for the manufacture or processing of instant photographic and peel...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manufacture or processing of instant photographic and peel-apart film articles. 723.175 Section 723.175... manufacture or processing of instant photographic and peel-apart film articles. (a) Purpose and scope. (1... film articles. This section does not apply to microorganisms subject to part 725 of this chapter....

  5. How Instant Messaging Affects the Satisfaction of Virtual Interpersonal Behavior of Taiwan Junior High School Students

    ERIC Educational Resources Information Center

    Lin, Chien-Huang; Sun, Ya-Chung; Lee, Yueh-Chiang; Wu, Shih-Chia

    2007-01-01

    Although Instant Messaging (IM) has established itself as one of the most popular modes of communication, little empirical research has explored how adolescents are affected by its use to satisfy their virtual interpersonal relationships. This research investigates cause and effect in the satisfaction of these relationships among adolescents in…

  6. Instant Video Revisiting: The Video Camera as a "Tool of the Mind" for Young Children.

    ERIC Educational Resources Information Center

    Forman, George

    1999-01-01

    Once used only to record special events in the classroom, video cameras are now small enough and affordable enough to be used to document everyday events. Video cameras, with foldout screens, allow children to watch their activities immediately after they happen and to discuss them with a teacher. This article coins the term instant video…

  7. Efficacy of Barabasz's Instant Alert Hypnosis in the Treatment of ADHD with Neurotherapy.

    ERIC Educational Resources Information Center

    Anderson, Kathryn; Barabasz, Marianne; Barabasz, Arreed; Warner, Dennis

    2000-01-01

    Tested use of instant alert hypnosis on 16 children diagnosed with attention deficit disorder. Found that EEG beta-theta ratio means were significantly higher in trials of neurotherapy combined with alert hypnosis than neurotherapy alone. Beta was significantly enhanced, whereas theta was inhibited. Identified improved treatment efficacy and…

  8. WhatsApp Goes to School: Mobile Instant Messaging between Teachers and Students

    ERIC Educational Resources Information Center

    Bouhnik, Dan; Deshen, Mor

    2014-01-01

    WhatsApp is a Smartphone application for instant messaging. Lately the application's popularity has risen. One of the unique features of the application is its ability to enhance communication within a group. Classroom communication between teaching faculty and high school students using WhatsApp has not yet, to our knowledge, been researched…

  9. Instant Experience in Clinical Trials: A Computer-Aided Simulation Technique

    ERIC Educational Resources Information Center

    Simpson, Michael A.

    1976-01-01

    Describes "Instant Experience," a simulation and game method in which students are given information about a promising new drug and asked to design a protocol for a clinical trial of the drug. Evaluation of a trial workshop showed positive response to the method. Educational goals to be achieved through its use are noted. (JT)

  10. Constant Companions: Instant Messaging Conversations as Sustainable Supportive Study Structures amongst Undergraduate Peers

    ERIC Educational Resources Information Center

    Timmis, Sue

    2012-01-01

    Universities are facing severe cuts in funding and a transformation of both the economic model underpinning higher education and the relationship between students, tutors and universities and the traditional forms of support for students' learning may be eroded. At the same time, mobile communications, instant messaging and social networking are…

  11. Becoming Embedded: Incorporating Instant Messaging and the Ongoing Evolution of a Virtual Reference Service

    ERIC Educational Resources Information Center

    Stormont, Sam

    2010-01-01

    The creation of an instant messaging (IM) service is described. The challenges encountered in developing, launching, and maintaining the project are examined and include technical support, archiving, balancing different formats, privacy, assessment, training, and the effectiveness of the IM channel. The process of choosing an aggregator and a…

  12. Complicating Contexts: Issues of Methodology in Researching the Language and Literacies of Instant Messaging

    ERIC Educational Resources Information Center

    Jacobs, Gloria E.

    2004-01-01

    This commentary discusses the methodological challenges of researching the intersection of online and offline activities of an adolescent girl engaged in instant messaging. If the New Literacy Studies stance that literacy practices are locally situated is accepted, a methodology for interrogating the multiple online and offline contexts that…

  13. Instant Messaging for Creating Interactive and Collaborative m-Learning Environments

    ERIC Educational Resources Information Center

    Kadirire, James

    2007-01-01

    "Instant Messaging" (IM) and "Presence," which is essentially the ability of being able to detect if other users are logged in on the network and send them messages in real time, has become one of the most popular applications of the Internet, causing people to want to stay connected to the Internet for inordinate amounts of time, a phenomena that…

  14. Mobile Immersion: An Experiment Using Mobile Instant Messenger to Support Second-Language Learning

    ERIC Educational Resources Information Center

    Lai, Arthur

    2016-01-01

    Immersion has been an acclaimed approach for second-language acquisition, but is not available to most students. The idea of this study was to create a mobile immersion environment on a smartphone using a mobile instant messenger, WhatsApp™. Forty-five Form-1 (7th grade) students divided into the Mobile Group and Control Group participated in a…

  15. Instant multigrain porridge: effect of cooking treatment on physicochemical and functional properties.

    PubMed

    Mandge, Harshad M; Sharma, Savita; Dar, Basharat Nabi

    2014-01-01

    Multigrain blends of wheat, mungbean, sorghum, barley, corn (50:20:15:10:5) and flaxseeds @ 1% were processed by instantization (cooking) treatments to produce instant multigrain porridge. Cooking treatment involved three processing steps, Soaking (A: Soaked for 5 h at 50 °C, B: Soaked for 3.5 h at 65 °C), Steaming at 15 psi for 10, 15, 20 min. and drying at 40 °C. Quality evaluation (physical, textural and sensory) of multigrain porridge was used as criteria to select the best processing condition for instantization. Per cent water absorption of grains increased significantly with increase in soaking time/temperature. Complete gelatinization of starch with no stickiness in cooked grains was obtained at 65 °C/3.5 h (soaking) followed by steaming (15 psi/15 min). The results suggest that multigrain blends can be instantized into an acceptable and nutritional, traditional breakfast food (porridge). The multigrain porridge given soaking treatment at 65 °C/3.5 h and steaming treatment for 20 min was having better physical and sensory properties.

  16. Instant multigrain porridge: effect of cooking treatment on physicochemical and functional properties.

    PubMed

    Mandge, Harshad M; Sharma, Savita; Dar, Basharat Nabi

    2014-01-01

    Multigrain blends of wheat, mungbean, sorghum, barley, corn (50:20:15:10:5) and flaxseeds @ 1% were processed by instantization (cooking) treatments to produce instant multigrain porridge. Cooking treatment involved three processing steps, Soaking (A: Soaked for 5 h at 50 °C, B: Soaked for 3.5 h at 65 °C), Steaming at 15 psi for 10, 15, 20 min. and drying at 40 °C. Quality evaluation (physical, textural and sensory) of multigrain porridge was used as criteria to select the best processing condition for instantization. Per cent water absorption of grains increased significantly with increase in soaking time/temperature. Complete gelatinization of starch with no stickiness in cooked grains was obtained at 65 °C/3.5 h (soaking) followed by steaming (15 psi/15 min). The results suggest that multigrain blends can be instantized into an acceptable and nutritional, traditional breakfast food (porridge). The multigrain porridge given soaking treatment at 65 °C/3.5 h and steaming treatment for 20 min was having better physical and sensory properties. PMID:24426053

  17. Instant ticket purchasing by Ontario baby boomers: increasing risk for problem gamblers.

    PubMed

    Papoff, Katharine M; Norris, Joan E

    2009-06-01

    Instant ticket purchase gambling (ITPG) is pervasive in Ontario and has features that mimic slot machine play. Previous researchers have reported that ITPG is one preferred activity for at-risk/problem gamblers. In the general Canadian population, rate of participation in ITPG is second only to lottery ticket gambling. Both are particularly favored by youth and seniors. The next cohort of seniors will be Canada's baby boomers, one-third of whom live in Ontario. Secondary analysis of Statistics Canada data revealed that adults in this cohort who buy instant gambling tickets (N = 1781) are significantly different from the complete group of their age peers (N = 4266) in number of activities pursued and frequency of involvement. At-risk/problem gambling prevalence was 10.2% amongst Ontario baby boomers who participate in instant ticket gambling, significantly higher than the 6.7% found amongst the total group of baby boom gamblers. For those who reported experiencing one or more of the Canadian Problem Gambling Index indicators for problem gambling (N = 237), 73% were buying instant tickets. Future research should consider cohort effects and explore combinations of preferred gambling activities that may increase risk for problem gambling. Social policy recommendations include the use of all ITPG venues as key locations for promoting awareness of problem gambling treatment services. PMID:19247820

  18. Can Students Really Multitask? An Experimental Study of Instant Messaging while Reading

    ERIC Educational Resources Information Center

    Bowman, Laura L.; Levine, Laura E.; Waite, Bradley M.; Gendron, Michael

    2010-01-01

    Students often "multitask" with electronic media while doing schoolwork. We examined the effects of one form of media often used in such multitasking, instant messaging (IM). We predicted that students who engaged in IMing while reading a typical academic psychology passage online would take longer to read the passage and would perform more poorly…

  19. Effects of Mobile Instant Messaging on Collaborative Learning Processes and Outcomes: The Case of South Korea

    ERIC Educational Resources Information Center

    Kim, Hyewon; Lee, MiYoung; Kim, Minjeong

    2014-01-01

    The purpose of this paper was to investigate the effects of mobile instant messaging on collaborative learning processes and outcomes. The collaborative processes were measured in terms of different types of interactions. We measured the outcomes of the collaborations through both the students' taskwork and their teamwork. The collaborative…

  20. Real-Time Computer-Mediated Communication: Email and Instant Messaging Simulation

    ERIC Educational Resources Information Center

    Newman, Amy

    2007-01-01

    As computer-mediated communication becomes increasingly prevalent in the workplace, students need to apply effective writing principles to today's technologies. Email, in particular, requires interns and new hires to manage incoming messages, use an appropriate tone, and craft clear, concise messages. In addition, with instant messaging (IM)…

  1. Corrective Feedback via Instant Messenger Learning Activities in NS-NNS and NNS-NNS Dyads

    ERIC Educational Resources Information Center

    Sotillo, Susana

    2005-01-01

    This exploratory study examines corrective feedback in native speaker-nonnative speaker (NS-NNS) and NNS-NNS dyads while participants were engaged in communicative and problem-solving activities via "Yahoo! Instant Messenger" (YIM). As "negotiation of meaning" studies of the 1990s have shown, linguistic items which learners negotiate in…

  2. Miniature stereoscopic video system provides real-time 3D registration and image fusion for minimally invasive surgery

    NASA Astrophysics Data System (ADS)

    Yaron, Avi; Bar-Zohar, Meir; Horesh, Nadav

    2007-02-01

    Sophisticated surgeries require the integration of several medical imaging modalities, like MRI and CT, which are three-dimensional. Many efforts are invested in providing the surgeon with this information in an intuitive & easy to use manner. A notable development, made by Visionsense, enables the surgeon to visualize the scene in 3D using a miniature stereoscopic camera. It also provides real-time 3D measurements that allow registration of navigation systems as well as 3D imaging modalities, overlaying these images on the stereoscopic video image in real-time. The real-time MIS 'see through tissue' fusion solutions enable the development of new MIS procedures in various surgical segments, such as spine, abdomen, cardio-thoracic and brain. This paper describes 3D surface reconstruction and registration methods using Visionsense camera, as a step toward fully automated multi-modality 3D registration.

  3. Toward 3D-IPTV: design and implementation of a stereoscopic and multiple-perspective video streaming system

    NASA Astrophysics Data System (ADS)

    Petrovic, Goran; Farin, Dirk; de With, Peter H. N.

    2008-02-01

    3D-Video systems allow a user to perceive depth in the viewed scene and to display the scene from arbitrary viewpoints interactively and on-demand. This paper presents a prototype implementation of a 3D-video streaming system using an IP network. The architecture of our streaming system is layered, where each information layer conveys a single coded video signal or coded scene-description data. We demonstrate the benefits of a layered architecture with two examples: (a) stereoscopic video streaming, (b) monoscopic video streaming with remote multiple-perspective rendering. Our implementation experiments confirm that prototyping 3D-video streaming systems is possible with today's software and hardware. Furthermore, our current operational prototype demonstrates that highly heterogeneous clients can coexist in the system, ranging from auto-stereoscopic 3D displays to resource-constrained mobile devices.

  4. Geometric analysis on stereoscopic images captured by single high-definition television camera on lunar orbiter Kaguya (SELENE)

    NASA Astrophysics Data System (ADS)

    Miura, Masato; Arai, Jun; Yamazaki, Junichi; Sasaki, Hisayuki; Okui, Makoto; Sobue, Shin-ichi; Okano, Fumio

    2010-04-01

    We present a generating method of stereoscopic images from moving pictures captured by a single high-definition television camera mounted on the Japanese lunar orbiter Kaguya (Selenological and Engineering Explorer, SELENE). Since objects in the moving pictures look as if they are moving vertically, vertical disparity is caused by the time offset of the sequence. This vertical disparity is converted into horizontal disparity by rotating the images by 90 degrees. We can create stereoscopic images using the rotated images as the images for a left and right eyes. However, this causes spatial distortion resulting from the axi-asymmetrical positions of the corresponding left and right cameras. We reduced this by adding a depth map that was obtained by assuming that the lunar surface was spherical. We confirmed that we could provide more acceptable views of the Moon by using the correction method.

  5. Snapshot Spectral Domain Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Valdez, Ashley

    Optical coherence tomography systems are used to image the retina in 3D to allow ophthalmologists diagnose ocular disease. These systems yield large data sets that are often labor-intensive to analyze and require significant expertise in order to draw conclusions, especially when used over time to monitor disease progression. Spectral Domain Optical Coherence Tomography (SD-OCT) instantly acquires depth profiles at a single location with a broadband source. These systems require mechanical scanning to generate two- or three-dimensional images. Instead of mechanically scanning, a beamlet array was used to permit multiple depth measurements on the retina with a single snapshot using a 3x 3 beamlet array. This multi-channel system was designed, assembled, and tested using a 1 x 2 beamlet lens array instead of a 3 x 3 beamlet array as a proof of concept prototype. The source was a superluminescent diode centered at 840nm with a 45nm bandwidth. Theoretical axial resolution was 6.92um and depth of focus was 3.45mm. Glass samples of varying thickness ranging from 0.18mm to 1.14mm were measured with the system to validate that correct depth profiles can be acquired for each channel. The results demonstrated the prototype system performed as expected, and is ready to be modified for in vivo applicability.

  6. 3D-MAD: A Full Reference Stereoscopic Image Quality Estimator Based on Binocular Lightness and Contrast Perception.

    PubMed

    Zhang, Yi; Chandler, Damon M

    2015-11-01

    Algorithms for a stereoscopic image quality assessment (IQA) aim to estimate the qualities of 3D images in a manner that agrees with human judgments. The modern stereoscopic IQA algorithms often apply 2D IQA algorithms on stereoscopic views, disparity maps, and/or cyclopean images, to yield an overall quality estimate based on the properties of the human visual system. This paper presents an extension of our previous 2D most apparent distortion (MAD) algorithm to a 3D version (3D-MAD) to evaluate 3D image quality. The 3D-MAD operates via two main stages, which estimate perceived quality degradation due to 1) distortion of the monocular views and 2) distortion of the cyclopean view. In the first stage, the conventional MAD algorithm is applied on the two monocular views, and then the combined binocular quality is estimated via a weighted sum of the two estimates, where the weights are determined based on a block-based contrast measure. In the second stage, intermediate maps corresponding to the lightness distance and the pixel-based contrast are generated based on a multipathway contrast gain-control model. Then, the cyclopean view quality is estimated by measuring the statistical-difference-based features obtained from the reference stereopair and the distorted stereopair, respectively. Finally, the estimates obtained from the two stages are combined to yield an overall quality score of the stereoscopic image. Tests on various 3D image quality databases demonstrate that our algorithm significantly improves upon many other state-of-the-art 2D/3D IQA algorithms. PMID:26186775

  7. Recent variation of the Las Vacas Glacier Mt. Aconcagua region, Central Andes, Argentina, based on ASTER stereoscopic images

    NASA Astrophysics Data System (ADS)

    Lenzano, M. G.; Leiva, J. C.; Lenzano, L.

    2010-01-01

    This work presents the results of the ASTER stereoscopic image processing to calculate the volume changes of Las Vacas Glacier. The processing of medium resolution satellite images (ASTER level 1A - pixel 15 m) from February 2001 and 2007 was performed applying the satellite digital photogrammetry method (Kääb, 2005). The comparison of the two generated DTM returns results that are acceptable within the parameters and precisions that can be obtained with this kind of sensor and the processing methodology.

  8. Tissue feature-based intra-fractional motion tracking for stereoscopic x-ray image guided radiotherapy.

    PubMed

    Xie, Yaoqin; Xing, Lei; Gu, Jia; Liu, Wu

    2013-06-01

    Real-time knowledge of tumor position during radiation therapy is essential to overcome the adverse effect of intra-fractional organ motion. The goal of this work is to develop a tumor tracking strategy by effectively utilizing the inherent image features of stereoscopic x-ray images acquired during dose delivery. In stereoscopic x-ray image guided radiation delivery, two orthogonal x-ray images are acquired either simultaneously or sequentially. The essence of markerless tumor tracking is the reliable identification of inherent points with distinct tissue features on each projection image and their association between two images. The identification of the feature points on a planar x-ray image is realized by searching for points with high intensity gradient. The feature points are associated by using the scale invariance features transform descriptor. The performance of the proposed technique is evaluated by using images of a motion phantom and four archived clinical cases acquired using either a CyberKnife equipped with a stereoscopic x-ray imaging system, or a LINAC equipped with an onboard kV imager and an electronic portal imaging device. In the phantom study, the results obtained using the proposed method agree with the measurements to within 2 mm in all three directions. In the clinical study, the mean error is 0.48 ± 0.46 mm for four patient data with 144 sequential images. In this work, a tissue feature-based tracking method for stereoscopic x-ray image guided radiation therapy is developed. The technique avoids the invasive procedure of fiducial implantation and may greatly facilitate the clinical workflow.

  9. Development of a miniaturized system for monitoring vergence during viewing of stereoscopic imagery using a head-mounted display

    NASA Astrophysics Data System (ADS)

    Ames, Shelly L.; McBrien, Neville A.

    2004-05-01

    Head-mounted displays (HMDs) are popular for viewing stereoscopic imagery due of their immersive qualities. However, symptoms and visual problems are commonly associated with their use. The discrepancy between vergence and accommodation cues, present in stereoscopic imagery, has been implicated in these adverse effects. The aim of this investigation was to develop a high resolution but relatively inexpensive on-line vergence monitoring system for use within a HMD to enable important information about the vergence response to be obtained. The new vergence monitoring system utilized infrared (IR) light emitting diodes (LEDs) for illumination and miniature charge couple infrared (CCIR) cameras, one for each eye, to capture images of the eyes. The infrared light reflected from the eyes was directed to the cameras via cube beam splitters which allowed an uninterrupted line of sight to the HMD screens. An image acquisition board was used to capture the images and a program was designed using LabVIEW to process the images. The resolution was at least 0.2 degrees, which translates to vergence changes of 7 cm from the image plane of the V6 HMD. The vergence monitoring system enables a better understanding of the contribution of accommodation and vergence mismatch to symptoms and visual problems associated with viewing stereoscopic imagery.

  10. Trade-offs arising from mixture of color cueing and monocular, binoptic, and stereoscopic cueing information for simulated rotorcraft flight

    NASA Technical Reports Server (NTRS)

    Parrish, Russell V.; Williams, Steven P.

    1993-01-01

    To provide stereopsis, binocular helmet-mounted display (HMD) systems must trade some of the total field of view available from their two monocular fields to obtain a partial overlap region. The visual field then provides a mixture of cues, with monocular regions on both peripheries and a binoptic (the same image in both eyes) region or, if lateral disparity is introduced to produce two images, a stereoscopic region in the overlapped center. This paper reports on in-simulator assessment of the trade-offs arising from the mixture of color cueing and monocular, binoptic, and stereoscopic cueing information in peripheral monitoring displays as utilized in HMD systems. The accompanying effect of stereoscopic cueing in the tracking information in the central region of the display is also assessed. The pilot's task for the study was to fly at a prescribed height above an undulating pathway in the sky while monitoring a dynamic bar chart displayed in the periphery of their field of view. Control of the simulated rotorcraft was limited to the longitudinal and vertical degrees of freedom to ensure the lateral separation of the viewing conditions of the concurrent tasks.

  11. Computed Tomography (CT) - Spine

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Spine Computed tomography (CT) of the spine is a diagnostic imaging ... Spine? What is CT Scanning of the Spine? Computed tomography, more commonly known as a CT or CAT ...

  12. Quality Index for Stereoscopic Images by Separately Evaluating Adding and Subtracting

    PubMed Central

    Yang, Jiachen; Lin, Yancong; Gao, Zhiqun; Lv, Zhihan; Wei, Wei; Song, Houbing

    2015-01-01

    The human visual system (HVS) plays an important role in stereo image quality perception. Therefore, it has aroused many people’s interest in how to take advantage of the knowledge of the visual perception in image quality assessment models. This paper proposes a full-reference metric for quality assessment of stereoscopic images based on the binocular difference channel and binocular summation channel. For a stereo pair, the binocular summation map and binocular difference map are computed first by adding and subtracting the left image and right image. Then the binocular summation is decoupled into two parts, namely additive impairments and detail losses. The quality of binocular summation is obtained as the adaptive combination of the quality of detail losses and additive impairments. The quality of binocular summation is computed by using the Contrast Sensitivity Function (CSF) and weighted multi-scale (MS-SSIM). Finally, the quality of binocular summation and binocular difference is integrated into an overall quality index. The experimental results indicate that compared with existing metrics, the proposed metric is highly consistent with the subjective quality assessment and is a robust measure. The result have also indirectly proved hypothesis of the existence of binocular summation and binocular difference channels. PMID:26717412

  13. Subjective quality assessment for stereoscopic video: case study on robust watermarking

    NASA Astrophysics Data System (ADS)

    Bensaied, R.; Mitrea, M.; Chammem, A.; Ebrahimi, T.

    2014-03-01

    This paper investigates three key issues related to full reference subjective quality evaluation tests for stereoscopic video, namely, the number of quality levels on the grading scale, the number of observers in the evaluation panel, and the inter-gender variability. It is theoretically demonstrated that the scores assigned by the observers on a continuous grading scale can be a posteriori mapped to any discrete grading scale, with controlled statistical accuracy. The experiments, performed in laboratory conditions, consider image quality, depth perception and visual comfort. The original content (i.e. the full reference) is represented by the 3DLive corpus, composed of 2 hours 11 minutes of HD 3DTV content. The modified content (i.e. the content to be evaluated) is obtained by watermarking this corpus with four methods. A panel of 60 observers (32 males and 28 females) was established from which further randomly selected sub-panels of 30 and 15 observers were also subsequently extracted. In order to simulate a continuous scale, the subjective evaluation was carried out on 100 quality levels, which are a posteriori mapped to discrete scales of q quality levels, with q between 2 and 9. The statistical investigation focused on the Mean Opinion Score and considered three types of statistical inferences: outliers detection, confidence limits, and paired t-tests.

  14. Precise positioning surveillance in 3-D using night-vision stereoscopic photogrammetry

    NASA Astrophysics Data System (ADS)

    Schwartz, Jason M.

    2011-06-01

    A 3-D imaging technique is presented which pairs high-resolution night-vision cameras with GPS to increase the capabilities of passive imaging surveillance. Camera models and GPS are used to derive a registered point cloud from multiple night-vision images. These point clouds are used to generate 3-D scene models and extract real-world positions of mission critical objects. Analysis shows accuracies rivaling laser scanning even in near-total darkness. The technique has been tested on stereoscopic 3-D video collections as well. Because this technique does not rely on active laser emissions it is more portable, less complex, less costly, and less detectable than laser scanning. This study investigates close-range photogrammetry under night-vision lighting conditions using practical use-case examples of terrain modeling, covert facility surveillance, and stand-off facial recognition. The examples serve as the context for discussion of a standard processing workflow. Results include completed, geo-referenced 3-D models, assessments of related accuracy and precision, and a discussion of future activities.

  15. Volume Attenuation and High Frequency Loss as Auditory Depth Cues in Stereoscopic 3D Cinema

    NASA Astrophysics Data System (ADS)

    Manolas, Christos; Pauletto, Sandra

    2014-09-01

    Assisted by the technological advances of the past decades, stereoscopic 3D (S3D) cinema is currently in the process of being established as a mainstream form of entertainment. The main focus of this collaborative effort is placed on the creation of immersive S3D visuals. However, with few exceptions, little attention has been given so far to the potential effect of the soundtrack on such environments. The potential of sound both as a means to enhance the impact of the S3D visual information and to expand the S3D cinematic world beyond the boundaries of the visuals is large. This article reports on our research into the possibilities of using auditory depth cues within the soundtrack as a means of affecting the perception of depth within cinematic S3D scenes. We study two main distance-related auditory cues: high-end frequency loss and overall volume attenuation. A series of experiments explored the effectiveness of these auditory cues. Results, although not conclusive, indicate that the studied auditory cues can influence the audience judgement of depth in cinematic 3D scenes, sometimes in unexpected ways. We conclude that 3D filmmaking can benefit from further studies on the effectiveness of specific sound design techniques to enhance S3D cinema.

  16. Formalizing the potential of stereoscopic 3D user experience in interactive entertainment

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Masuch, Maic

    2015-03-01

    The use of stereoscopic 3D vision affects how interactive entertainment has to be developed as well as how it is experienced by the audience. The large amount of possibly impacting factors and variety as well as a certain subtlety of measured effects on user experience make it difficult to grasp the overall potential of using S3D vision. In a comprehensive approach, we (a) present a development framework which summarizes possible variables in display technology, content creation and human factors, and (b) list a scheme of S3D user experience effects concerning initial fascination, emotions, performance, and behavior as well as negative feelings of discomfort and complexity. As a major contribution we propose a qualitative formalization which derives dependencies between development factors and user effects. The argumentation is based on several previously published user studies. We further show how to apply this formula to identify possible opportunities and threats in content creation as well as how to pursue future steps for a possible quantification.

  17. Quality Index for Stereoscopic Images by Separately Evaluating Adding and Subtracting.

    PubMed

    Yang, Jiachen; Lin, Yancong; Gao, Zhiqun; Lv, Zhihan; Wei, Wei; Song, Houbing

    2015-01-01

    The human visual system (HVS) plays an important role in stereo image quality perception. Therefore, it has aroused many people's interest in how to take advantage of the knowledge of the visual perception in image quality assessment models. This paper proposes a full-reference metric for quality assessment of stereoscopic images based on the binocular difference channel and binocular summation channel. For a stereo pair, the binocular summation map and binocular difference map are computed first by adding and subtracting the left image and right image. Then the binocular summation is decoupled into two parts, namely additive impairments and detail losses. The quality of binocular summation is obtained as the adaptive combination of the quality of detail losses and additive impairments. The quality of binocular summation is computed by using the Contrast Sensitivity Function (CSF) and weighted multi-scale (MS-SSIM). Finally, the quality of binocular summation and binocular difference is integrated into an overall quality index. The experimental results indicate that compared with existing metrics, the proposed metric is highly consistent with the subjective quality assessment and is a robust measure. The result have also indirectly proved hypothesis of the existence of binocular summation and binocular difference channels. PMID:26717412

  18. Three-Dimensional High-Resolution Optical/X-Ray Stereoscopic Tracking Velocimetry

    NASA Technical Reports Server (NTRS)

    Cha, Soyoung S.; Ramachandran, Naryanan

    2005-01-01

    Measurement of three-dimensional (3-D) three-component velocity fields is of great importance in a variety of research and industrial applications for understanding materials processing, fluid physics, and strain/displacement measurements. The 3-D experiments in these fields most likely inhibit the use of conventional techniques, which are based only on planar and optically-transparent-field observation. Here, we briefly review the current status of 3-D diagnostics for motion/velocity detection, for both optical and x-ray systems. As an initial step for providing 3-D capabilities, we have developed stereoscopic tracking velocimetry (STV) to measure 3-D flow/deformation through optical observation. The STV is advantageous in system simplicity, for continually observing 3-D phenomena in near real-time. In an effort to enhance the data processing through automation and to avoid the confusion in tracking numerous markers or particles, artificial neural networks are employed to incorporate human intelligence. Our initial optical investigations have proven the STV to be a very viable candidate for reliably measuring 3-D flow motions. With previous activities focused on improving the processing efficiency, overall accuracy, and automation based on the optical system, the current efforts is directed to the concurrent expansion to the x-ray system for broader experimental applications.

  19. Three-Dimensional High-Resolution Optical/X-Ray Stereoscopic Tracking Velocimetry

    NASA Technical Reports Server (NTRS)

    Cha, Soyoung S.; Ramachandran, Narayanan

    2004-01-01

    Measurement of three-dimensional (3-D) three-component velocity fields is of great importance in a variety of research and industrial applications for understanding materials processing, fluid physics, and strain/displacement measurements. The 3-D experiments in these fields most likely inhibit the use of conventional techniques, which are based only on planar and optically-transparent-field observation. Here, we briefly review the current status of 3-D diagnostics for motion/velocity detection, for both optical and x-ray systems. As an initial step for providing 3-D capabilities, we nave developed stereoscopic tracking velocimetry (STV) to measure 3-D flow/deformation through optical observation. The STV is advantageous in system simplicity, for continually observing 3- D phenomena in near real-time. In an effort to enhance the data processing through automation and to avoid the confusion in tracking numerous markers or particles, artificial neural networks are employed to incorporate human intelligence. Our initial optical investigations have proven the STV to be a very viable candidate for reliably measuring 3-D flow motions. With previous activities are focused on improving the processing efficiency, overall accuracy, and automation based on the optical system, the current efforts is directed to the concurrent expansion to the x-ray system for broader experimental applications.

  20. Unsteady flow in the nasal cavity with high flow therapy measured by stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Spence, C. J. T.; Buchmann, N. A.; Jermy, M. C.

    2012-03-01

    Nasal high flow (NHF) cannulae are used to deliver heated and humidified air to patients at steady flows ranging from 5 to 50 l/min. In this study, the flow velocities in the nasal cavity across the complete respiratory cycle during natural breathing and with NHF has been mapped in vitro using time-resolved stereoscopic particle image velocimetry (SPIV). An anatomically accurate silicone resin model of a complete human nasal cavity was constructed using CT scan data and rapid prototyping. Physiological breathing waveforms were reproduced in vitro using Reynolds and Womersley number matching and a piston pump driven by a ball screw and stepper motor. The flow pattern in the nasal cavity with NHF was found to differ significantly from natural breathing. Velocities of 2.4 and 3.3 ms-1 occurred in the nasal valve during natural breathing at peak expiration and inspiration, respectively; however, on expiration, the maximum velocity of 3.8 ms-1 occurred in the nasopharynx. At a cannula flow rate of 30 l/min, maximal velocities of 13.6 and 16.5 ms-1 at peak expiration and inspiration, respectively, were both located in the cannula jet within the nasal valve. Results are presented that suggest the quasi-steady flow assumption is invalid in the nasal cavity during natural breathing; however, it was valid with NHF. Cannula flow has been found to continuously flush the nasopharyngeal dead space, which may enhance carbon dioxide removal and increase oxygen fraction.

  1. Experimental study on a smart wheelchair system using a combination of stereoscopic and spherical vision.

    PubMed

    Nguyen, Jordan S; Su, Steven W; Nguyen, Hung T

    2013-01-01

    This paper is concerned with the experimental study performance of a smart wheelchair system named TIM (Thought-controlled Intelligent Machine), which uses a unique camera configuration for vision. Included in this configuration are stereoscopic cameras for 3-Dimensional (3D) depth perception and mapping ahead of the wheelchair, and a spherical camera system for 360-degrees of monocular vision. The camera combination provides obstacle detection and mapping in unknown environments during real-time autonomous navigation of the wheelchair. With the integration of hands-free wheelchair control technology, designed as control methods for people with severe physical disability, the smart wheelchair system can assist the user with automated guidance during navigation. An experimental study on this system was conducted with a total of 10 participants, consisting of 8 able-bodied subjects and 2 tetraplegic (C-6 to C-7) subjects. The hands-free control technologies utilized for this testing were a head-movement controller (HMC) and a brain-computer interface (BCI). The results showed the assistance of TIM's automated guidance system had a statistically significant reduction effect (p-value = 0.000533) on the completion times of the obstacle course presented in the experimental study, as compared to the test runs conducted without the assistance of TIM.

  2. Stereoscopic filming for investigating evasive side-stepping and anterior cruciate ligament injury risk

    NASA Astrophysics Data System (ADS)

    Lee, Marcus J. C.; Bourke, Paul; Alderson, Jacqueline A.; Lloyd, David G.; Lay, Brendan

    2010-02-01

    Non-contact anterior cruciate ligament (ACL) injuries are serious and debilitating, often resulting from the performance of evasive sides-stepping (Ssg) by team sport athletes. Previous laboratory based investigations of evasive Ssg have used generic visual stimuli to simulate realistic time and space constraints that athletes experience in the preparation and execution of the manoeuvre. However, the use of unrealistic visual stimuli to impose these constraints may not be accurately identifying the relationship between the perceptual demands and ACL loading during Ssg in actual game environments. We propose that stereoscopically filmed footage featuring sport specific opposing defender/s simulating a tackle on the viewer, when used as visual stimuli, could improve the ecological validity of laboratory based investigations of evasive Ssg. Due to the need for precision and not just the experience of viewing depth in these scenarios, a rigorous filming process built on key geometric considerations and equipment development to enable a separation of 6.5 cm between two commodity cameras had to be undertaken. Within safety limits, this could be an invaluable tool in enabling more accurate investigations of the associations between evasive Ssg and ACL injury risk.

  3. User evaluation of a stereoscopic display for space-training applications

    NASA Astrophysics Data System (ADS)

    Gorski, Arthur M.

    1992-06-01

    Space Shuttle missions and future Space Station Freedom activities both require a significant amount of out-the-window viewing to perform a variety of on-orbit tasks such as grappling objects with a robot arm, berthing payloads into the shuttle cargo bay, and docking the shuttle to the station. Many of these tasks take place close enough to the viewer such that stereo depth cues become useful and important. Astronaut crews spend many hours of ground training practicing these tasks using visual simulation without stereo depth cues. A prototype of a stereoscopic display system for use in these training scenarios has been constructed. Training instructors and development contractor personnel were asked to evaluate the display system for training suitability. Evaluators were also asked to judge the quality of stereo cues, long term viewing comfort, and degree of display artifacts. Results were compared to related research to develop recommendations for scene content and viewing distance and suggest the direction of further research to improve comfort and depth perception.

  4. Systematic stereoscopic analyses for cloacal development: The origin of anorectal malformations

    PubMed Central

    Matsumaru, Daisuke; Murashima, Aki; Fukushima, Junichi; Senda, Syuhei; Matsushita, Shoko; Nakagata, Naomi; Miyajima, Masayasu; Yamada, Gen

    2015-01-01

    The division of the embryonic cloaca is the most essential event for the formation of digestive and urinary tracts. The defective development of the cloaca results in anorectal malformations (ARMs; 2–5 per 10,000 live births). However, the developmental and pathogenic mechanisms of ARMs are unclear. In the current study, we visualized the epithelia in the developing cloaca and nephric ducts (NDs). Systemic stereoscopic analyses revealed that the ND-cloaca connection sites shifted from the lateral-middle to dorsal-anterior part of the cloaca during cloacal division from E10.5 to E11.5 in mouse embryos. Genetic cell labeling analyses revealed that the cells in the ventral cloacal epithelium in the early stages rarely contributed to the dorsal part. Moreover, we revealed the possible morphogenetic movement of endodermal cells within the anterior part of the urogenital sinus and hindgut. These results provide the basis for understanding both cloacal development and the ARM pathogenesis. PMID:26354024

  5. Instantaneous dynamic change detection based on three-line-array stereoscopic images of TH-1 satellite

    NASA Astrophysics Data System (ADS)

    Zheng, Tuanjie; Cheng, Jiasheng; Li, Heyuan

    2014-05-01

    TH-1 satellite loading three-line array stereoscopic camera, can scanning 3 times from different directions on the same region or target within the time for about 1 minute, conducive to regional monitoring or target instantaneous change monitoring. Based on the time difference of forward, nadir and backward images of the three-line-array camera of TH-1 Satellite, this paper gives a method to get regional dynamic change image by processing of geometric and physical consistency under the principle of photogrammetry, and to construct the model of change detection by the quantitative results of change detection under the improvement and optimization of noise filtering algorithm. The experimental results show that, by using the detection results of forward, nadir and backward images of the three-line -array camera of TH-1 Satellite, moving distance and velocity can be accurately calculated, and quantitative monitoring of topography changes can be achieved, which not only has temporal resolution, but also can't be achieved by other environmental monitoring satellites. It's significant for flood, fire, clouds, or motion detectors. TH-1 satellite is China's first generation of transmission photogrammetry satellite. With the more satellites networking operation, and higher spatial and temporal resolution, The TH satellites will play a greater role in the field of Earth observation. This article merely uses the principles of photogrammetry to consider photography deformation from different directions, and thorough study will aim at shadow and sun elevation angle, to fully realize the monitoring of changes in topography and moving targets.

  6. Towards disparity joint upsampling for robust stereoscopic endoscopic scene reconstruction in robotic prostatectomy

    NASA Astrophysics Data System (ADS)

    Luo, Xiongbiao; McLeod, A. Jonathan; Jayarathne, Uditha L.; Pautler, Stephen E.; Schlacta, Christopher M.; Peters, Terry M.

    2016-03-01

    Three-dimensional (3-D) scene reconstruction from stereoscopic binocular laparoscopic videos is an effective way to expand the limited surgical field and augment the structure visualization of the organ being operated in minimally invasive surgery. However, currently available reconstruction approaches are limited by image noise, occlusions, textureless and blurred structures. In particular, an endoscope inside the body only has the limited light source resulting in illumination non-uniformities in the visualized field. These limitations unavoidably deteriorate the stereo image quality and hence lead to low-resolution and inaccurate disparity maps, resulting in blurred edge structures in 3-D scene reconstruction. This paper proposes an improved stereo correspondence framework that integrates cost-volume filtering with joint upsampling for robust disparity estimation. Joint bilateral upsampling, joint geodesic upsampling, and tree filtering upsampling were compared to enhance the disparity accuracy. The experimental results demonstrate that joint upsampling provides an effective way to boost the disparity estimation and hence to improve the surgical endoscopic scene 3-D reconstruction. Moreover, the bilateral upsampling generally outperforms the other two upsampling methods in disparity estimation.

  7. Evaluation of passive polarized stereoscopic 3D display for visual & mental fatigues.

    PubMed

    Amin, Hafeez Ullah; Malik, Aamir Saeed; Mumtaz, Wajid; Badruddin, Nasreen; Kamel, Nidal

    2015-01-01

    Visual and mental fatigues induced by active shutter stereoscopic 3D (S3D) display have been reported using event-related brain potentials (ERP). An important question, that is whether such effects (visual & mental fatigues) can be found in passive polarized S3D display, is answered here. Sixty-eight healthy participants are divided into 2D and S3D groups and subjected to an oddball paradigm after being exposed to S3D videos with passive polarized display or 2D display. The age and fluid intelligence ability of the participants are controlled between the groups. ERP results do not show any significant differences between S3D and 2D groups to find the aftereffects of S3D in terms of visual and mental fatigues. Hence, we conclude that passive polarized S3D display technology may not induce visual and/or mental fatigue which may increase the cognitive load and suppress the ERP components. PMID:26738049

  8. Gradients of relative disparity underlie the perceived slant of stereoscopic surfaces.

    PubMed

    Wardle, Susan G; Gillam, Barbara J

    2016-01-01

    Perceived stereoscopic slant around a vertical axis is strongly underestimated for isolated surfaces, suggesting that neither uniocular image compression nor linear gradients of absolute disparity are very effective cues. However, slant increases to a level close to geometric prediction if gradients of relative disparity are introduced, for example by placing flanking frontal-parallel surfaces at the horizontal boundaries of the slanted surface. Here we examine the mechanisms underlying this slant enhancement by manipulating properties of the slanted surface or the flanking surfaces. Perceived slant was measured using a probe bias method. In Experiment 1, an outlined surface and a randomly textured surface showed similar slant underestimation when presented in isolation, but the enhancement in slant produced by flankers was significantly greater for the textured surface. In Experiment 2, we degraded the relative disparity gradient by (a) reducing overall texture density, (b) reducing flanker width, or (c) adding disparity noise to the flankers. Density had no effect while adding noise to the flankers, or reducing their width significantly decreased perceived slant of the central surface. These results support the view that the enhancement of slant produced by adding flanking surfaces is attributable to the presence of a relative disparity gradient and that the flanker effect can spread to regions of the surface not directly above or below the gradient. PMID:26998800

  9. Stereoscopic Height and Wind Retrievals for Aerosol Plumes with the MISR INteractive eXplorer (MINX)

    NASA Technical Reports Server (NTRS)

    Nelson, D.L.; Garay, M.J.; Kahn, Ralph A.; Dunst, Ben A.

    2013-01-01

    The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard the Terra satellite acquires imagery at 275-m resolution at nine angles ranging from 0deg (nadir) to 70deg off-nadir. This multi-angle capability facilitates the stereoscopic retrieval of heights and motion vectors for clouds and aerosol plumes. MISR's operational stereo product uses this capability to retrieve cloud heights and winds for every satellite orbit, yielding global coverage every nine days. The MISR INteractive eXplorer (MINX) visualization and analysis tool complements the operational stereo product by providing users the ability to retrieve heights and winds locally for detailed studies of smoke, dust and volcanic ash plumes, as well as clouds, at higher spatial resolution and with greater precision than is possible with the operational product or with other space-based, passive, remote sensing instruments. This ability to investigate plume geometry and dynamics is becoming increasingly important as climate and air quality studies require greater knowledge about the injection of aerosols and the location of clouds within the atmosphere. MINX incorporates features that allow users to customize their stereo retrievals for optimum results under varying aerosol and underlying surface conditions. This paper discusses the stereo retrieval algorithms and retrieval options in MINX, and provides appropriate examples to explain how the program can be used to achieve the best results.

  10. Study of the performance of stereoscopic panomorph systems calibrated with traditional pinhole model

    NASA Astrophysics Data System (ADS)

    Poulin-Girard, Anne-Sophie; Thibault, Simon; Laurendeau, Denis

    2016-06-01

    With their large field of view, anamorphosis, and areas of enhanced magnification, panomorph lenses are an interesting choice for navigation systems for mobile robotics in which knowledge of the surroundings is mandatory. However, panomorph lenses special characteristics can be challenging during the calibration process. This study focuses on the calibration of two panomorph stereoscopic systems with a model and technique developed for narrow-angle lenses, the "Camera Calibration Toolbox for MATLAB." In order to assess the performance of the systems, the mean reprojection error (MRE) related to the calibration and the reconstruction error of control points of an object of interest at various locations in the field of view are used. The calibrations were successful and exhibit MREs of less than one pixel in all cases. However, some poorly reconstructed control points illustrate that an acceptable MRE guarantees neither the quality of 3-D reconstruction nor its uniformity in the field of view. In addition, the nonuniformity in the 3-D reconstruction quality indicates that panomorph lenses require a more accurate estimation of the principal point (center of distortion) coordinates to improve the calibration and therefore the 3-D reconstruction.

  11. Immersive Molecular Visualization with Omnidirectional Stereoscopic Ray Tracing and Remote Rendering

    PubMed Central

    Stone, John E.; Sherman, William R.; Schulten, Klaus

    2016-01-01

    Immersive molecular visualization provides the viewer with intuitive perception of complex structures and spatial relationships that are of critical interest to structural biologists. The recent availability of commodity head mounted displays (HMDs) provides a compelling opportunity for widespread adoption of immersive visualization by molecular scientists, but HMDs pose additional challenges due to the need for low-latency, high-frame-rate rendering. State-of-the-art molecular dynamics simulations produce terabytes of data that can be impractical to transfer from remote supercomputers, necessitating routine use of remote visualization. Hardware-accelerated video encoding has profoundly increased frame rates and image resolution for remote visualization, however round-trip network latencies would cause simulator sickness when using HMDs. We present a novel two-phase rendering approach that overcomes network latencies with the combination of omnidirectional stereoscopic progressive ray tracing and high performance rasterization, and its implementation within VMD, a widely used molecular visualization and analysis tool. The new rendering approach enables immersive molecular visualization with rendering techniques such as shadows, ambient occlusion lighting, depth-of-field, and high quality transparency, that are particularly helpful for the study of large biomolecular complexes. We describe ray tracing algorithms that are used to optimize interactivity and quality, and we report key performance metrics of the system. The new techniques can also benefit many other application domains. PMID:27747138

  12. Temporal presentation protocols in stereoscopic displays: Flicker visibility, perceived motion, and perceived depth

    PubMed Central

    Hoffman, David M.; Karasev, Vasiliy I.; Banks, Martin S.

    2011-01-01

    Most stereoscopic displays rely on field-sequential presentation to present different images to the left and right eyes. With sequential presentation, images are delivered to each eye in alternation with dark intervals, and each eye receives its images in counter phase with the other eye. This type of presentation can exacerbate image artifacts including flicker, and the appearance of unsmooth motion. To address the flicker problem, some methods repeat images multiple times before updating to new ones. This greatly reduces flicker visibility, but makes motion appear less smooth. This paper describes an investigation of how different presentation methods affect the visibility of flicker, motion artifacts, and distortions in perceived depth. It begins with an examination of these methods in the spatio-temporal frequency domain. From this examination, it describes a series of predictions for how presentation rate, object speed, simultaneity of image delivery to the two eyes, and other properties ought to affect flicker, motion artifacts, and depth distortions, and reports a series of experiments that tested these predictions. The results confirmed essentially all of the predictions. The paper concludes with a summary and series of recommendations for the best approach to minimize these undesirable effects. PMID:21572544

  13. Pixel-level tunable liquid crystal lenses for auto-stereoscopic display

    NASA Astrophysics Data System (ADS)

    Li, Kun; Robertson, Brian; Pivnenko, Mike; Chu, Daping; Zhou, Jiong; Yao, Jun

    2014-02-01

    Mobile video and gaming are now widely used, and delivery of a glass-free 3D experience is of both research and development interest. The key drawbacks of a conventional 3D display based on a static lenticular lenslet array and parallax barriers are low resolution, limited viewing angle and reduced brightness, mainly because of the need of multiple-pixels for each object point. This study describes the concept and performance of pixel-level cylindrical liquid crystal (LC) lenses, which are designed to steer light to the left and right eye sequentially to form stereo parallax. The width of the LC lenses can be as small as 20-30 μm, so that the associated auto-stereoscopic display will have the same resolution as the 2D display panel in use. Such a thin sheet of tunable LC lens array can be applied directly on existing mobile displays, and can deliver 3D viewing experience while maintaining 2D viewing capability. Transparent electrodes were laser patterned to achieve the single pixel lens resolution, and a high birefringent LC material was used to realise a large diffraction angle for a wide field of view. Simulation was carried out to model the intensity profile at the viewing plane and optimise the lens array based on the measured LC phase profile. The measured viewing angle and intensity profile were compared with the simulation results.

  14. Training pilots to visualize large-scale spatial relationships in a stereoscopic display

    NASA Astrophysics Data System (ADS)

    Mowafy, Lyn; Thurman, Richard A.

    1993-09-01

    In flying air intercepts, a fighter pilot must plan most tactical maneuvers well before acquiring visual contact. Success depends on one's ability to create an accurate mental model of dynamic 3D spatial relationships from 2D information displays. This paper describes an Air Force training program for visualizing large- scale dynamic spatial relationships. It employs a low-cost, portable system in which the helmet-mounted stereoscopic display reveals the unobservable spatial relationships in a virtual world. We also describe recent research which evaluated the training effectiveness of this interactive three-dimensional display technology. Three display formats have been tested for their impact on the pilot's ability to encode, retain and recall functionally relevant spatial information: (1) a set of 2D orthographic plan views, (2) a flat panel 3D perspective rendering and, (3) the 3D virtual environment. Trainees flew specified air intercepts and reviewed the flights in one of the display formats. Experts' trajectories were provided for comparison. After training, flight performance was tested on a new set of scenarios. Differences in pilots' performances under the three formats suggest how virtual environment displays can aid people learning to visualize 3D spatial relationships from 2D information.

  15. DEM Extraction from High-Resolution Stereoscopic Worldview 1 & 2 Imagery of Polar Outlet Glaciers

    NASA Astrophysics Data System (ADS)

    Porter, C. C.; Morin, P. J.; Howat, I. M.; Niebuhr, S.; Smith, B. E.

    2011-12-01

    There are few reliable digital elevation models (DEMs) in polar regions and most are of low resolution (on the order of 100's of meters to km) or of poor quality. Polar environments are changing rapidly and accurate DEMs are critical for correcting imagery, measuring glacier thickness changes and modeling ice flow and surface melt water drainage. Using in-track stereoscopic images from Worldview-1 and Worldview-2, we derived high-resolution DEMs for outlet glaciers and other areas of interest in Antarctica and the Arctic. We used ERDAS Imagine's LPS eATE (enhanced automated terrain extraction) algorithm to derive a dense point cloud of matches. The resulting point cloud is comparable in density to that obtained by LiDAR flown at 10,000 feet. Preliminary comparisons of our results to ground control points collected by field teams and airborne and satellite laser altimeters show 0.5 - 10 meter vertical error over glaciers and 2 - 10 meter error over ice-free terrain. The error is primarily due to approximations in the sensor model and is consistent across the DEM. Our results indicate that refinements in the sensor model and point matching algorithm will improve accuracy. Given the increasing interest in glacier change detection around the globe, DEMs extracted from frequent satellite stereo pairs can be used to monitor and quantify changes in both movement and volume.

  16. Assessing the benefits of stereoscopic displays to visual search: methodology and initial findings

    NASA Astrophysics Data System (ADS)

    Godwin, Hayward J.; Holliman, Nick S.; Menneer, Tamaryn; Liversedge, Simon P.; Cave, Kyle R.; Donnelly, Nicholas

    2015-03-01

    Visual search is a task that is carried out in a number of important security and health related scenarios (e.g., X-ray baggage screening, radiography). With recent and ongoing developments in the technology available to present images to observers in stereoscopic depth, there has been increasing interest in assessing whether depth information can be used in complex search tasks to improve search performance. Here we outline the methodology that we developed, along with both software and hardware information, in order to assess visual search performance in complex, overlapping stimuli that also contained depth information. In doing so, our goal is to foster further research along these lines in the future. We also provide an overview with initial results of the experiments that we have conducted involving participants searching stimuli that contain overlapping objects presented on different depth planes to one another. Thus far, we have found that depth information does improve the speed (but not accuracy) of search, but only when the stimuli are highly complex and contain a significant degree of overlap. Depth information may therefore aid real-world search tasks that involve the examination of complex, overlapping stimuli.

  17. A guide for human factors research with stereoscopic 3D displays

    NASA Astrophysics Data System (ADS)

    McIntire, John P.; Havig, Paul R.; Pinkus, Alan R.

    2015-05-01

    In this work, we provide some common methods, techniques, information, concepts, and relevant citations for those conducting human factors-related research with stereoscopic 3D (S3D) displays. We give suggested methods for calculating binocular disparities, and show how to verify on-screen image separation measurements. We provide typical values for inter-pupillary distances that are useful in such calculations. We discuss the pros, cons, and suggested uses of some common stereovision clinical tests. We discuss the phenomena and prevalence rates of stereoanomalous, pseudo-stereoanomalous, stereo-deficient, and stereoblind viewers. The problems of eyestrain and fatigue-related effects from stereo viewing, and the possible causes, are enumerated. System and viewer crosstalk are defined and discussed, and the issue of stereo camera separation is explored. Typical binocular fusion limits are also provided for reference, and discussed in relation to zones of comfort. Finally, the concept of measuring disparity distributions is described. The implications of these issues for the human factors study of S3D displays are covered throughout.

  18. Visual fatigue modeling for stereoscopic video shot based on camera motion

    NASA Astrophysics Data System (ADS)

    Shi, Guozhong; Sang, Xinzhu; Yu, Xunbo; Liu, Yangdong; Liu, Jing

    2014-11-01

    As three-dimensional television (3-DTV) and 3-D movie become popular, the discomfort of visual feeling limits further applications of 3D display technology. The cause of visual discomfort from stereoscopic video conflicts between accommodation and convergence, excessive binocular parallax, fast motion of objects and so on. Here, a novel method for evaluating visual fatigue is demonstrated. Influence factors including spatial structure, motion scale and comfortable zone are analyzed. According to the human visual system (HVS), people only need to converge their eyes to the specific objects for static cameras and background. Relative motion should be considered for different camera conditions determining different factor coefficients and weights. Compared with the traditional visual fatigue prediction model, a novel visual fatigue predicting model is presented. Visual fatigue degree is predicted using multiple linear regression method combining with the subjective evaluation. Consequently, each factor can reflect the characteristics of the scene, and the total visual fatigue score can be indicated according to the proposed algorithm. Compared with conventional algorithms which ignored the status of the camera, our approach exhibits reliable performance in terms of correlation with subjective test results.

  19. Stereoscopic augmented reality using ultrasound volume rendering for laparoscopic surgery in children

    NASA Astrophysics Data System (ADS)

    Oh, Jihun; Kang, Xin; Wilson, Emmanuel; Peters, Craig A.; Kane, Timothy D.; Shekhar, Raj

    2014-03-01

    In laparoscopic surgery, live video provides visualization of the exposed organ surfaces in the surgical field, but is unable to show internal structures beneath those surfaces. The laparoscopic ultrasound is often used to visualize the internal structures, but its use is limited to intermittent confirmation because of the need for an extra hand to maneuver the ultrasound probe. Other limitations of using ultrasound are the difficulty of interpretation and the need for an extra port. The size of the ultrasound transducer may also be too large for its usage in small children. In this paper, we report on an augmented reality (AR) visualization system that features continuous hands-free volumetric ultrasound scanning of the surgical anatomy and video imaging from a stereoscopic laparoscope. The acquisition of volumetric ultrasound image is realized by precisely controlling a back-and-forth movement of an ultrasound transducer mounted on a linear slider. Furthermore, the ultrasound volume is refreshed several times per minute. This scanner will sit outside of the body in the envisioned use scenario and could be even integrated into the operating table. An overlay of the maximum intensity projection (MIP) of ultrasound volume on the laparoscopic stereo video through geometric transformations features an AR visualization system particularly suitable for children, because ultrasound is radiation-free and provides higher-quality images in small patients. The proposed AR representation promises to be better than the AR representation using ultrasound slice data.

  20. National Instant Criminal Background Check Improvement Act: implications for persons with mental illness.

    PubMed

    Price, Marilyn; Norris, Donna M

    2008-01-01

    The National Instant Criminal Background Check Improvement Act has serious implications for persons with mental illness with regard to the ability to purchase firearms. Federally prohibited persons include those who have been adjudicated as mentally defective, or have been committed to a mental institution, or are unlawful users of or are addicted to a controlled substance. The legislation was intended to expand the reporting practices of states by providing significant financial incentives and disincentives for releasing all relevant records, including those contained within mental health databases, to the National Instant Criminal Background Check System (NICS). As of April 2007, only 22 states were voluntarily submitting records from mental health databases to the NICS. The legislation was introduced following the Virginia Tech tragedy, when public opinion favored tightening control over access to firearms of persons with mental illness.

  1. Development of a doxycycline-inducible lentiviral plasmid with an instant regulatory feature.

    PubMed

    Yang, Tian; Burrows, Christopher; Park, Jeong Hyeon

    2014-03-01

    Lentiviruses provide highly efficient gene delivery vehicles in both dividing and non-dividing cells. Inducible gene expression systems often employ a specific cell line that constitutively expresses a regulatory protein for transgene expression. As one of such inducible expression systems the Tet-On system uses a cell line expressing reverse tetracycline-responsive transcriptional activator (rtTA). The rtTA protein binds to the tetracycline-responsive element (TRE) in the promoter and activates transcription of a transgene in a doxycycline-dependent manner. To establish a universal and instant regulatory system without generating Tet-On cell lines, the cDNAs of rtTA and a testing target gene (PPM1B) were cloned in the bi-directional TRE-containing promoters. Here, we examined whether a basal leaky expression of rtTA allows instantly inducible expression of both rtTA itself and the target gene, PPM1B in a single plasmid using the two mini-CMV promoters. Transient transfection of the lentiviral plasmids into human embryonic kidney HEK293T cells showed a significant induction of PPM1B expression in response to doxycycline, suggesting that these lentiviral plasmids can be used as an instantly inducible mammalian expression vector. However, the expression of rtTA by lentiviral transduction shows a minimal expression without a consistent response to doxycycline, suggesting that the utility of these lentiviral vectors is limited. A potential solution to overcome lentiviral transgene inactivation is proposed. PMID:24727543

  2. Stereoscopic camera and viewing systems with undistorted depth presentation and reduced or eliminated erroneous acceleration and deceleration perceptions, or with perceptions produced or enhanced for special effects

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B. (Inventor)

    1991-01-01

    Methods for providing stereoscopic image presentation and stereoscopic configurations using stereoscopic viewing systems having converged or parallel cameras may be set up to reduce or eliminate erroneously perceived accelerations and decelerations by proper selection of parameters, such as an image magnification factor, q, and intercamera distance, 2w. For converged cameras, q is selected to be equal to Ve - qwl = 0, where V is the camera distance, e is half the interocular distance of an observer, w is half the intercamera distance, and l is the actual distance from the first nodal point of each camera to the convergence point, and for parallel cameras, q is selected to be equal to e/w. While converged cameras cannot be set up to provide fully undistorted three-dimensional views, they can be set up to provide a linear relationship between real and apparent depth and thus minimize erroneously perceived accelerations and decelerations for three sagittal planes, x = -w, x = 0, and x = +w which are indicated to the observer. Parallel cameras can be set up to provide fully undistorted three-dimensional views by controlling the location of the observer and by magnification and shifting of left and right images. In addition, the teachings of this disclosure can be used to provide methods of stereoscopic image presentation and stereoscopic camera configurations to produce a nonlinear relation between perceived and real depth, and erroneously produce or enhance perceived accelerations and decelerations in order to provide special effects for entertainment, training, or educational purposes.

  3. Turbocharging Quantum Tomography

    SciTech Connect

    Blume-Kohout, Robin J.; Gamble, John King; Nielsen, Erik; Maunz, Peter Lukas Wilhelm; Scholten, Travis L.; Rudinger, Kenneth Michael

    2015-01-01

    Quantum tomography is used to characterize quantum operations implemented in quantum information processing (QIP) hardware. Traditionally, state tomography has been used to characterize the quantum state prepared in an initialization procedure, while quantum process tomography is used to characterize dynamical operations on a QIP system. As such, tomography is critical to the development of QIP hardware (since it is necessary both for debugging and validating as-built devices, and its results are used to influence the next generation of devices). But tomography suffers from several critical drawbacks. In this report, we present new research that resolves several of these flaws. We describe a new form of tomography called gate set tomography (GST), which unifies state and process tomography, avoids prior methods critical reliance on precalibrated operations that are not generally available, and can achieve unprecedented accuracies. We report on theory and experimental development of adaptive tomography protocols that achieve far higher fidelity in state reconstruction than non-adaptive methods. Finally, we present a new theoretical and experimental analysis of process tomography on multispin systems, and demonstrate how to more effectively detect and characterize quantum noise using carefully tailored ensembles of input states.

  4. Calibration grooming and alignment for LDUA High Resolution Stereoscopic Video Camera System (HRSVS)

    SciTech Connect

    Pardini, A.F.

    1998-01-27

    The High Resolution Stereoscopic Video Camera System (HRSVS) was designed by the Savannah River Technology Center (SRTC) to provide routine and troubleshooting views of tank interiors during characterization and remediation phases of underground storage tank (UST) processing. The HRSVS is a dual color camera system designed to provide stereo viewing of the interior of the tanks including the tank wall in a Class 1, Division 1, flammable atmosphere. The HRSVS was designed with a modular philosophy for easy maintenance and configuration modifications. During operation of the system with the LDUA, the control of the camera system will be performed by the LDUA supervisory data acquisition system (SDAS). Video and control status 1458 will be displayed on monitors within the LDUA control center. All control functions are accessible from the front panel of the control box located within the Operations Control Trailer (OCT). The LDUA will provide all positioning functions within the waste tank for the end effector. Various electronic measurement instruments will be used to perform CG and A activities. The instruments may include a digital volt meter, oscilloscope, signal generator, and other electronic repair equipment. None of these instruments will need to be calibrated beyond what comes from the manufacturer. During CG and A a temperature indicating device will be used to measure the temperature of the outside of the HRSVS from initial startup until the temperature has stabilized. This device will not need to be in calibration during CG and A but will have to have a current calibration sticker from the Standards Laboratory during any acceptance testing. This sensor will not need to be in calibration during CG and A but will have to have a current calibration sticker from the Standards Laboratory during any acceptance testing.

  5. Potential hazards of viewing 3-D stereoscopic television, cinema and computer games: a review.

    PubMed

    Howarth, Peter A

    2011-03-01

    The visual stimulus provided by a 3-D stereoscopic display differs from that of the real world because the image provided to each eye is produced on a flat surface. The distance from the screen to the eye remains fixed, providing a single focal distance, but the introduction of disparity between the images allows objects to be located geometrically in front of, or behind, the screen. Unlike in the real world, the stimulus to accommodation and the stimulus to convergence do not match. Although this mismatch is used positively in some forms of Orthoptic treatment, a number of authors have suggested that it could negatively lead to the development of asthenopic symptoms. From knowledge of the zone of clear, comfortable, single binocular vision one can predict that, for people with normal binocular vision, adverse symptoms will not be present if the discrepancy is small, but are likely if it is large, and that what constitutes 'large' and 'small' are idiosyncratic to the individual. The accommodation-convergence mismatch is not, however, the only difference between the natural and the artificial stimuli. In the former case, an object located in front of, or behind, a fixated object will not only be perceived as double if the images fall outside Panum's fusional areas, but it will also be defocused and blurred. In the latter case, however, it is usual for the producers of cinema, TV or computer game content to provide an image that is in focus over the whole of the display, and as a consequence diplopic images will be sharply in focus. The size of Panum's fusional area is spatial frequency-dependent, and because of this the high spatial frequencies present in the diplopic 3-D image will provide a different stimulus to the fusion system from that found naturally.

  6. Searching for Rapid Optical Transients with Both Eyes Open: The RAPTOR Stereoscopic Sky Monitoring System

    NASA Astrophysics Data System (ADS)

    Vestrand, W. T.; Borozdin, K.; Brumby, S.; Casperson, D.; Fenimore, E.; Galassi, M.; McGowan, K.; Priedhorsky, W.; Starr, D.; Wozniak, P.; White, R.; Wren, J.

    2003-03-01

    A largely unexplored area in astronomy is the study of explosive optical transients with durations of minutes or less.The existence of spectacular rapid optical transients was clearly demonstrated by the detections of bright optical transients associated with gamma ray bursts 990123 and 021211. Those detections were only possible because they occurred in the field-of-view of a high-energy satellite that was able to identify them in real time and cue robotic optical telescopes to slew to the correct position. But there are reasons to suspect the existence of explosive optical transients that cannot be detected by high-energy satellites---the optical emission might have a broader beaming pattern or could be a precursor to the high-energy emission. The RAPid Telescopes for Optical Response (RAPTOR) experiment is an autonomous closed-loop monitoring system that identifies and makes follow-up observations of rapid optical transients in real time. The system is composed of two telescope arrays, separated by 38 kilometers, that stereoscopically monitor a field of about 1300 square degrees for celestial transients down to about 12th magnitude in 30 seconds. The absence of measurable parallax is used to distinguish celestial transients from the "forest" non-celestial transients. Each array also contains a sensitive, higher resolution "fovea" telescope, capable of imaging at a faster cadence and providing color information. In a manner analogous to human vision, both arrays are mounted on rapidly slewing mounts so that the "fovea" of the array can be rapidly directed for follow-up observations of any interesting transient identified by the wide-field system. We discuss the initial results from this new wide-field optical monitoring system.

  7. Quad-plane stereoscopic PIV for fine-scale structure measurements in turbulence

    NASA Astrophysics Data System (ADS)

    Naka, Y.; Tomita, K.; Shimura, M.; Fukushima, N.; Tanahashi, M.; Miyauchi, T.

    2016-05-01

    The fine-scale structure in turbulence is investigated by quad-plane stereoscopic particle image velocimetry (QPSPIV). The quad-plane consists of two each of different polarizations and wavelengths, and it provides three velocity components at four independent parallel planes. Measurements have been undertaken in the developed region of a turbulent round jet with a spatial resolution sufficient to capture the small-scale structures. The advantage of the QPSPIV is presented in terms of the spectral response in the evaluation of the out-of-plane velocity gradient. The full velocity gradient tensor is computed with a fourth-order finite difference scheme in the out-of-plane direction as well as the in-plane directions. The turbulence quantities, such as the vorticity components, the energy dissipation rate and the second and third invariants of the velocity gradient tensor, are computed according to their faithful definitions. The coherent fine-scale eddies are extracted from the present QPSPIV data. The probability density functions of the diameter and the maximum azimuthal velocity of the extracted eddies exhibit their peak at approximately 8η and 1.5u_k, respectively, where η and u_k are the Kolmogorov length and velocity. These values agree well with the data in the literature. The phase-averaged distributions of turbulence quantities around the coherent fine-scale eddy indicate an apparent elliptic feature around the axis. Furthermore, the state of the strain rate exerting the eddy is quantified from the phase-averaged distributions of eigenvalues of the strain rate tensor and the alignment of the corresponding eigenvectors against the axis. The present study gives a solid experimental support of the coherent fine-scale structures in turbulence, and the technique can be applied to various flow fields and to the higher Reynolds number condition.

  8. Stereoscopic Observation of Slipping Reconnection in a Double Candle-flame-shaped Solar Flare

    NASA Astrophysics Data System (ADS)

    Gou, Tingyu; Liu, Rui; Wang, Yuming; Liu, Kai; Zhuang, Bin; Chen, Jun; Zhang, Quanhao; Liu, Jiajia

    2016-04-01

    The 2011 January 28 M1.4 flare exhibits two side-by-side candle-flame-shaped flare loop systems underneath a larger cusp-shaped structure during the decay phase, as observed at the northwestern solar limb by the Solar Dynamics Observatory. The northern loop system brightens following the initiation of the flare within the southern loop system, but all three cusp-shaped structures are characterized by ˜10 MK temperatures, hotter than the arch-shaped loops underneath. The “Ahead” satellite of the Solar Terrestrial Relations Observatory provides a top view, in which the post-flare loops brighten sequentially, with one end fixed while the other apparently slipping eastward. By performing stereoscopic reconstruction of the post-flare loops in EUV and mapping out magnetic connectivities, we found that the footpoints of the post-flare loops are slipping along the footprint of a hyperbolic flux tube (HFT) separating the two loop systems and that the reconstructed loops share similarity with the magnetic field lines that are traced starting from the same HFT footprint, where the field lines are relatively flexible. These results argue strongly in favor of slipping magnetic reconnection at the HFT. The slipping reconnection was likely triggered by the flare and manifested as propagative dimmings before the loop slippage is observed. It may contribute to the late-phase peak in Fe xvi 33.5 nm, which is even higher than its main-phase counterpart, and may also play a role in the density and temperature asymmetry observed in the northern loop system through heat conduction.

  9. Stereoscopic particle image velocimetry analysis of healthy and emphysemic alveolar sac models.

    PubMed

    Berg, Emily J; Robinson, Risa J

    2011-06-01

    Emphysema is a progressive lung disease that involves permanent destruction of the alveolar walls. Fluid mechanics in the pulmonary region and how they are altered with the presence of emphysema are not well understood. Much of our understanding of the flow fields occurring in the healthy pulmonary region is based on idealized geometries, and little attention has been paid to emphysemic geometries. The goal of this research was to utilize actual replica lung geometries to gain a better understanding of the mechanisms that govern fluid motion and particle transport in the most distal regions of the lung and to compare the differences that exist between healthy and emphysematous lungs. Excised human healthy and emphysemic lungs were cast, scanned, graphically reconstructed, and used to fabricate clear, hollow, compliant models. Three dimensional flow fields were obtained experimentally using stereoscopic particle image velocimetry techniques for healthy and emphysematic breathing conditions. Measured alveolar velocities ranged over two orders of magnitude from the duct entrance to the wall in both models. Recirculating flow was not found in either the healthy or the emphysematic model, while the average flow rate was three times larger in emphysema as compared to healthy. Diffusion dominated particle flow, which is characteristic in the pulmonary region of the healthy lung, was not seen for emphysema, except for very small particle sizes. Flow speeds dissipated quickly in the healthy lung (60% reduction in 0.25 mm) but not in the emphysematic lung (only 8% reduction 0.25 mm). Alveolar ventilation per unit volume was 30% smaller in emphysema compared to healthy. Destruction of the alveolar walls in emphysema leads to significant differences in flow fields between the healthy and emphysemic lung. Models based on replica geometry provide a useful means to quantify these differences and could ultimately improve our understanding of disease progression. PMID:21744924

  10. Mars Orbiter Camera Acquires High Resolution Stereoscopic Images of the Viking One Landing Site

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Two MOC images of the vicinity of the Viking Lander 1 (MOC 23503 and 25403), acquired separately on 12 April 1998 at 08:32 PDT and 21 April 1998 at 13:54 PDT (respectively), are combined here in a stereoscopic anaglyph. The more recent, slightly better quality image is in the red channel, while the earlier image is shown in the blue and green channels. Only the overlap portion of the images is included in the composite.

    Image 23503 was taken at a viewing angle of 31.6o from vertical; 25403 was taken at an angle of 22.4o, for a difference of 9.4o. Although this is not as large a difference as is typically used in stereo mapping, it is sufficient to provide some indication of relief, at least in locations of high relief.

    The image shows the raised rims and deep interiors of the larger impact craters in the area (the largest crater is about 650 m/2100 feet across). It shows that the relief on the ridges is very subtle, and that, in general, the Viking landing site is very flat. This result is, of course, expected: the VL-1 site was chosen specifically because it was likely to have low to very low slopes that represented potential hazards to the spacecraft.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  11. Directivity Patterns of Complex Solar Type III Radio Bursts: Stereoscopic Observations

    NASA Astrophysics Data System (ADS)

    Golla, T.; MacDowall, R. J.

    2014-12-01

    Complex solar type III-like radio bursts are a group of type III bursts that occur in association with slowly drifting type II radio bursts excited by coronal mass ejection (CME) driven shock waves. We presentsimultaneous observations of these radio bursts from the STEREO A, B and WIND spacecraft at low frequencies, located at different vantage points in the ecliptic plane. Using these stereoscopic observations, wedetermine the directivity of these complex radio bursts. We estimate the angles between the directions of the magnetic field at the sources and the lines connecting the source to the spacecraft (viewing angles) by assuming that the sources are located on the Parker spiral magnetic field lines emerging from the associated active regions into the spherically symmetric solar atmosphere. We estimate the normalized peak intensities of these bursts (directivity factors) at each spacecraft using their time profiles at each spacecraft. These observations indicate that the complex type III bursts can be divided into two groups: (1) bursts emitting into a very narrow cone centered around the tangent to the magnetic field, and (2) bursts emitting into a wider cone. We show that the bursts , which are emitted along the tangent to the spiral magnetic field lines at the source are very intense, and their intensities steadily fall as the viewing angles increase to higher values. We have developed a ray tracing code and computed the distributions of the trajectories of rays emitted at the fundamental and second harmonic of the electron plasma frequency. The comparison of the observed emission patterns with the computed distributions of the ray trajectories indicate that the intense bursts visible in a narrow range of angles around the magnetic field directions probably are emitted in the fundamental mode, whereas the relativelyweaker bursts visible to a wide range of angles are probably emitted in the harmonic mode.

  12. Stereoscopic particle image velocimetry analysis of healthy and emphysemic alveolar sac models.

    PubMed

    Berg, Emily J; Robinson, Risa J

    2011-06-01

    Emphysema is a progressive lung disease that involves permanent destruction of the alveolar walls. Fluid mechanics in the pulmonary region and how they are altered with the presence of emphysema are not well understood. Much of our understanding of the flow fields occurring in the healthy pulmonary region is based on idealized geometries, and little attention has been paid to emphysemic geometries. The goal of this research was to utilize actual replica lung geometries to gain a better understanding of the mechanisms that govern fluid motion and particle transport in the most distal regions of the lung and to compare the differences that exist between healthy and emphysematous lungs. Excised human healthy and emphysemic lungs were cast, scanned, graphically reconstructed, and used to fabricate clear, hollow, compliant models. Three dimensional flow fields were obtained experimentally using stereoscopic particle image velocimetry techniques for healthy and emphysematic breathing conditions. Measured alveolar velocities ranged over two orders of magnitude from the duct entrance to the wall in both models. Recirculating flow was not found in either the healthy or the emphysematic model, while the average flow rate was three times larger in emphysema as compared to healthy. Diffusion dominated particle flow, which is characteristic in the pulmonary region of the healthy lung, was not seen for emphysema, except for very small particle sizes. Flow speeds dissipated quickly in the healthy lung (60% reduction in 0.25 mm) but not in the emphysematic lung (only 8% reduction 0.25 mm). Alveolar ventilation per unit volume was 30% smaller in emphysema compared to healthy. Destruction of the alveolar walls in emphysema leads to significant differences in flow fields between the healthy and emphysemic lung. Models based on replica geometry provide a useful means to quantify these differences and could ultimately improve our understanding of disease progression.

  13. A new instrument for high resolution stereoscopic photography of falling hydrometeors with simultaneous measurement of fallspeed

    NASA Astrophysics Data System (ADS)

    Yuter, S. E.; Garrett, T. J.; Fallgatter, C.; Shkurko, K.; Howlett, D.; Dean, J.; Hardin, N.

    2012-12-01

    We introduce a new instrument, the Fallgatter Technologies Multi-Angle Snowflake Camera (MASC), that provides <30 micron resolution stereoscopic photographic images of individual large falling hydrometeors with accurate measurements of their fallspeed. Previously, identification of hydrometeor form has required initial collection on a flat surface, a process that is somewhat subjective and remarkably finicky due to the fragile nature of the particles. Other hydrometeor instruments such as the 2DVD, are automated and leave the particle untouched and provide fallspeed data. However, they provide only 200 micron resolution silhouettes, which can be insufficient for habit and riming identification and the requirements of microwave scattering calculations. The MASC is like the 2DVD but uses a sensitive IR motion sensor for a trigger and actually photographs the particle surface from multiple angles. Field measurements from Alta Ski Area near Salt Lake City are providing beautiful images and fallspeed data, suggesting that MASC measurements may help development of improved parameterizations for hydrometeor microwave scattering. Hundreds of thousands of images have been collected enabling comparisons of hydrometeor development, morphology and fallspeed with a co-located vertically pointing 24 GHz MicroRainRadar radar. Here we show multi-angle images from the MASC, size fallspeed relationships, and discrete dipole approximation scattering calculations for a range of hydrometeor forms at the frequencies of 24 GHz, 94 GHz and 183 GHz. The scattering calculations indicate that complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than graupel particles of similar size.

  14. Massively parallel neural circuits for stereoscopic color vision: encoding, decoding and identification.

    PubMed

    Lazar, Aurel A; Slutskiy, Yevgeniy B; Zhou, Yiyin

    2015-03-01

    Past work demonstrated how monochromatic visual stimuli could be faithfully encoded and decoded under Nyquist-type rate conditions. Color visual stimuli were then traditionally encoded and decoded in multiple separate monochromatic channels. The brain, however, appears to mix information about color channels at the earliest stages of the visual system, including the retina itself. If information about color is mixed and encoded by a common pool of neurons, how can colors be demixed and perceived? We present Color Video Time Encoding Machines (Color Video TEMs) for encoding color visual stimuli that take into account a variety of color representations within a single neural circuit. We then derive a Color Video Time Decoding Machine (Color Video TDM) algorithm for color demixing and reconstruction of color visual scenes from spikes produced by a population of visual neurons. In addition, we formulate Color Video Channel Identification Machines (Color Video CIMs) for functionally identifying color visual processing performed by a spiking neural circuit. Furthermore, we derive a duality between TDMs and CIMs that unifies the two and leads to a general theory of neural information representation for stereoscopic color vision. We provide examples demonstrating that a massively parallel color visual neural circuit can be first identified with arbitrary precision and its spike trains can be subsequently used to reconstruct the encoded stimuli. We argue that evaluation of the functional identification methodology can be effectively and intuitively performed in the stimulus space. In this space, a signal reconstructed from spike trains generated by the identified neural circuit can be compared to the original stimulus.

  15. Psycho-physiological effects of visual artifacts by stereoscopic display systems

    NASA Astrophysics Data System (ADS)

    Kim, Sanghyun; Yoshitake, Junki; Morikawa, Hiroyuki; Kawai, Takashi; Yamada, Osamu; Iguchi, Akihiko

    2011-03-01

    The methods available for delivering stereoscopic (3D) display using glasses can be classified as time-multiplexing and spatial-multiplexing. With both methods, intrinsic visual artifacts result from the generation of the 3D image pair on a flat panel display device. In the case of the time-multiplexing method, an observer perceives three artifacts: flicker, the Mach-Dvorak effect, and a phantom array. These only occur under certain conditions, with flicker appearing in any conditions, the Mach-Dvorak effect during smooth pursuit eye movements (SPM), and a phantom array during saccadic eye movements (saccade). With spatial-multiplexing, the artifacts are temporal-parallax (due to the interlaced video signal), binocular rivalry, and reduced spatial resolution. These artifacts are considered one of the major impediments to the safety and comfort of 3D display users. In this study, the implications of the artifacts for the safety and comfort are evaluated by examining the psychological changes they cause through subjective symptoms of fatigue and the depth sensation. Physiological changes are also measured as objective responses based on analysis of heart and brain activation by visual artifacts. Further, to understand the characteristics of each artifact and the combined effects of the artifacts, four experimental conditions are developed and tested. The results show that perception of artifacts differs according to the visual environment and the display method. Furthermore visual fatigue and the depth sensation are influenced by the individual characteristics of each artifact. Similarly, heart rate variability and regional cerebral oxygenation changes by perception of artifacts in conditions.

  16. The effect of stereoscopic acquisition parameters on both distortion and comfort

    NASA Astrophysics Data System (ADS)

    Black, Robert H.; Wuerger, Sophie M.; Meyer, Georg

    2014-03-01

    The purpose of our experiments was to investigate the effect of interaxial camera separation on the perceived shape and viewing comfort of 3D images. Horizontal Image Translation (HIT) and interaxial distance were altered together. Following Banks et al (2009), our stimuli were simple stereoscopic hinges and we measured the perceived angle as a function of camera separation. We compared the predictions based on ray tracing with the perceived 3D shape obtained psychophysically. 40 participants were asked to judge the angles of 250 hinges at different camera separations (interaxial and HIT linked a 20-100mm; angle range: 50°-130°). Comfort data was obtained using a five point Likert scale. Stimuli were presented in orthoscopic conditions with screen and observer Field of View (FOVO) matched at 45°. Our main results are: (1) For the 60mm camera separation, observers perceived a right angle correctly, but at other camera separations right angles were perceived as larger than 90° (camera separations > 60mm) or smaller than 90° (camera separations < 60 mm). (2) The observed perceptual deviations from a right angle were smaller than predicted based on disparity information (ray tracing model) alone. (3) We found an interaction between comfort and camera separation: only at the 60mm camera separation (e.g. at typical human eye separation) do we find a significant negative correlation between angle and comfort. All other camera separations, the disparity (angle) has no systematic effect on comfort. This research is set out to provide a foundation for tolerance limits for comfort and perceptual distortions brought about by various virtual camera separations.

  17. An analysis of brightness as a factor in visual discomfort caused by watching stereoscopic 3D video

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Woo; Kang, Hang-Bong

    2015-05-01

    Even though various research has examined the factors that cause visual discomfort in watching stereoscopic 3D video, the brightness factor has not been dealt with sufficiently. In this paper, we analyze visual discomfort under various illumination conditions by considering eye-blinking rate and saccadic eye movement. In addition, we measure the perceived depth before and after watching 3D stereoscopic video by using our own 3D depth measurement instruments. Our test sequences consist of six illumination conditions for background. The illumination is changed from bright to dark or vice-versa, while the illumination of the foreground object is constant. Our test procedure is as follows: First, the subjects are rested until a baseline of no visual discomfort is established. Then, the subjects answer six questions to check their subjective pre-stimulus discomfort level. Next, we measure perceived depth for each subject, and the subjects watch 30-minute stereoscopic 3D or 2D video clips in random order. We measured eye-blinking and saccadic movements of the subject using an eye-tracking device. Then, we measured perceived depth for each subject again to detect any changes in depth perception. We also checked the subject's post-stimulus discomfort level, and measured the perceived depth after a 40-minute post-experiment resting period to measure recovery levels. After 40 minutes, most subjects returned to normal levels of depth perception. From our experiments, we found that eye-blinking rates were higher with a dark to light video progression than vice-versa. Saccadic eye movements were a lower with a dark to light video progression than viceversa.

  18. Study of high-definition and stereoscopic head-aimed vision for improved teleoperation of an unmanned ground vehicle

    NASA Astrophysics Data System (ADS)

    Tyczka, Dale R.; Wright, Robert; Janiszewski, Brian; Chatten, Martha Jane; Bowen, Thomas A.; Skibba, Brian

    2012-06-01

    Nearly all explosive ordnance disposal robots in use today employ monoscopic standard-definition video cameras to relay live imagery from the robot to the operator. With this approach, operators must rely on shadows and other monoscopic depth cues in order to judge distances and object depths. Alternatively, they can contact an object with the robot's manipulator to determine its position, but that approach carries with it the risk of detonation from unintentionally disturbing the target or nearby objects. We recently completed a study in which high-definition (HD) and stereoscopic video cameras were used in addition to conventional standard-definition (SD) cameras in order to determine if higher resolutions and/or stereoscopic depth cues improve operators' overall performance of various unmanned ground vehicle (UGV) tasks. We also studied the effect that the different vision modes had on operator comfort. A total of six different head-aimed vision modes were used including normal-separation HD stereo, SD stereo, "micro" (reduced separation) SD stereo, HD mono, and SD mono (two types). In general, the study results support the expectation that higher resolution and stereoscopic vision aid UGV teleoperation, but the degree of improvement was found to depend on the specific task being performed; certain tasks derived notably more benefit from improved depth perception than others. This effort was sponsored by the Joint Ground Robotics Enterprise under Robotics Technology Consortium Agreement #69-200902 T01. Technical management was provided by the U.S. Air Force Research Laboratory's Robotics Research and Development Group at Tyndall AFB, Florida.

  19. Comparison Between Infrared Optical and Stereoscopic X-Ray Technologies for Patient Setup in Image Guided Stereotactic Radiotherapy

    SciTech Connect

    Tagaste, Barbara; Riboldi, Marco; Spadea, Maria F.; Bellante, Simone; Baroni, Guido; Cambria, Raffaella; Garibaldi, Cristina; Ciocca, Mario; Catalano, Gianpiero; Alterio, Daniela; Orecchia, Roberto

    2012-04-01

    Purpose: To compare infrared (IR) optical vs. stereoscopic X-ray technologies for patient setup in image-guided stereotactic radiotherapy. Methods and Materials: Retrospective data analysis of 233 fractions in 127 patients treated with hypofractionated stereotactic radiotherapy was performed. Patient setup at the linear accelerator was carried out by means of combined IR optical localization and stereoscopic X-ray image fusion in 6 degrees of freedom (6D). Data were analyzed to evaluate the geometric and dosimetric discrepancy between the two patient setup strategies. Results: Differences between IR optical localization and 6D X-ray image fusion parameters were on average within the expected localization accuracy, as limited by CT image resolution (3 mm). A disagreement between the two systems below 1 mm in all directions was measured in patients treated for cranial tumors. In extracranial sites, larger discrepancies and higher variability were observed as a function of the initial patient alignment. The compensation of IR-detected rotational errors resulted in a significantly improved agreement with 6D X-ray image fusion. On the basis of the bony anatomy registrations, the measured differences were found not to be sensitive to patient breathing. The related dosimetric analysis showed that IR-based patient setup caused limited variations in three cases, with 7% maximum dose reduction in the clinical target volume and no dose increase in organs at risk. Conclusions: In conclusion, patient setup driven by IR external surrogates localization in 6D featured comparable accuracy with respect to procedures based on stereoscopic X-ray imaging.

  20. Stereoscopic helmet mounted system for real time 3D environment reconstruction and indoor ego-motion estimation

    NASA Astrophysics Data System (ADS)

    Donato, Giuseppe; Sequeira, Vitor M.; Sadka, Abdul

    2008-04-01

    A novel type of stereoscopic Helmet Mounted System for simultaneous user localization and mapping applications is described. This paper presents precise real time volume data reconstruction. The system is designed for users that need to explore and navigate in unprepared indoor environments without any support of GPS signal or environment preparation through preinstalled markers. Augmented Reality features in support of self-navigation can be interactively added by placing virtual markers in the desired positions in the world coordinate system. They can then be retrieved when the marker is back in the user field of view being used as visual alerts or for back path finding.

  1. The Effects of Actual Human Size Display and Stereoscopic Presentation on Users' Sense of Being Together with and of Psychological Immersion in a Virtual Character

    PubMed Central

    Ahn, Dohyun; Seo, Youngnam; Kim, Minkyung; Kwon, Joung Huem; Jung, Younbo; Ahn, Jungsun

    2014-01-01

    Abstract This study examined the role of display size and mode in increasing users' sense of being together with and of their psychological immersion in a virtual character. Using a high-resolution three-dimensional virtual character, this study employed a 2×2 (stereoscopic mode vs. monoscopic mode×actual human size vs. small size display) factorial design in an experiment with 144 participants randomly assigned to each condition. Findings showed that stereoscopic mode had a significant effect on both users' sense of being together and psychological immersion. However, display size affected only the sense of being together. Furthermore, display size was not found to moderate the effect of stereoscopic mode. PMID:24606057

  2. Instant Coaching.

    ERIC Educational Resources Information Center

    Birch, Paul

    This book is intended to help managers coach individuals and groups; assess current performance; develop a coaching plan; keep track of whether their coaching is having the right effect; and learn how to motivate and communicate effectively. Chapters 1-3 establish what coaching is; who can coach; and who can be coached. Chapter 4 lays coaching out…

  3. Partially converted stereoscopic images and the effects on visual attention and memory

    NASA Astrophysics Data System (ADS)

    Kim, Sanghyun; Morikawa, Hiroyuki; Mitsuya, Reiko; Kawai, Takashi; Watanabe, Katsumi

    2015-03-01

    This study contained two experimental examinations of the cognitive activities such as visual attention and memory in viewing stereoscopic (3D) images. For this study, partially converted 3D images were used with binocular parallax added to a specific region of the image. In Experiment 1, change blindness was used as a presented stimulus. The visual attention and impact on memory were investigated by measuring the response time to accomplish the given task. In the change blindness task, an 80 ms blank was intersected between the original and altered images, and the two images were presented alternatingly for 240 ms each. Subjects were asked to temporarily memorize the two switching images and to compare them, visually recognizing the difference between the two. The stimuli for four conditions (2D, 3D, Partially converted 3D, distracted partially converted 3D) were randomly displayed for 20 subjects. The results of Experiment 1 showed that partially converted 3D images tend to attract visual attention and are prone to remain in viewer's memory in the area where moderate negative parallax has been added. In order to examine the impact of a dynamic binocular disparity on partially converted 3D images, an evaluation experiment was conducted that applied learning, distraction, and recognition tasks for 33 subjects. The learning task involved memorizing the location of cells in a 5 × 5 matrix pattern using two different colors. Two cells were positioned with alternating colors, and one of the gray cells was moved up, down, left, or right by one cell width. Experimental conditions was set as a partially converted 3D condition in which a gray cell moved diagonally for a certain period of time with a dynamic binocular disparity added, a 3D condition in which binocular disparity was added to all gray cells, and a 2D condition. The correct response rates for recognition of each task after the distraction task were compared. The results of Experiment 2 showed that the correct

  4. Optometric measurements predict performance but not comfort on a virtual object placement task with a stereoscopic three-dimensional display

    NASA Astrophysics Data System (ADS)

    McIntire, John P.; Wright, Steve T.; Harrington, Lawrence K.; Havig, Paul R.; Watamaniuk, Scott N. J.; Heft, Eric L.

    2014-06-01

    Twelve participants were tested on a simple virtual object precision placement task while viewing a stereoscopic three-dimensional (S3-D) display. Inclusion criteria included uncorrected or best corrected vision of 20/20 or better in each eye and stereopsis of at least 40 arc sec using the Titmus stereotest. Additionally, binocular function was assessed, including measurements of distant and near phoria (horizontal and vertical) and distant and near horizontal fusion ranges using standard optometric clinical techniques. Before each of six 30 min experimental sessions, measurements of phoria and fusion ranges were repeated using a Keystone View Telebinocular and an S3-D display, respectively. All participants completed experimental sessions in which the task required the precision placement of a virtual object in depth at the same location as a target object. Subjective discomfort was assessed using the simulator sickness questionnaire. Individual placement accuracy in S3-D trials was significantly correlated with several of the binocular screening outcomes: viewers with larger convergent fusion ranges (measured at near distance), larger total fusion ranges (convergent plus divergent ranges, measured at near distance), and/or lower (better) stereoscopic acuity thresholds were more accurate on the placement task. No screening measures were predictive of subjective discomfort, perhaps due to the low levels of discomfort induced.

  5. Dual seven pinhole tomography

    SciTech Connect

    Bizais, Y.; Zubal, I.G.; Rowe, R.W.; Bennett, G.W.; Brill, A.B.

    1982-01-01

    Emission tomography using two orthogonal sets of projections through seven pinhole collimators is considered. This paper describes the acquisition system, the reconstruction algorithm, presents results obtained in phantom studies, and discusses the advantages and disadvantages of this method over conventional Seven Pinhole Tomography.

  6. Computed body tomography.

    PubMed

    Alfidi, R J; Haaga, J R

    1976-12-01

    Only the surface of the diagnostic possibilities inherent in CT imaging has been scratched. Solic organ pathology is readily visible in most instances by computed tomography. With further extension of present knowledge and development of newer contrast agents, the ability of computed body tomography to image a wide range of diseases appears almost limitless.

  7. InstantLabs Listeria species food safety kit. Performance tested methods 041304.

    PubMed

    Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit

    2014-01-01

    The InstantLabs Listeria Species Food SafetyKitwas validated against the International Organization for Standardization (ISO) reference method 11290-1 for the detection of Listeria monocytogenes and other Listeria species. The matrixes (stainless steel, sealed concrete, cheddar cheese, raw shrimp, and hot dogs) were inoculated with approximately 1 CFU/test portion of various Listeria species to generate fractional positives (5-15) in 20 inoculated samples. Enrichments were also fractionally inoculated with L. monocytogenes for side-by-side testing of the InstantLabs Listeria monocytogenes Food Safety Kit. Stainless steel and sealed concrete samples were validated using 4 x 4" and 1 x 1" test areas, respectively, and enriched in Buffered Listeria Enrichment Broth (BLEB) at 35 +/- 1 degrees C for 22-28 h. All food samples were tested at 25 g or 25 mL and enriched in BLEB at 35 +/- 1 degrees C for 24-28 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of Listeria species on stainless steel, sealed concrete, cheddar cheese, raw shrimp, and hot dogs. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 80 Listeria species and 30 non-Listeria species examined. The method was shown to be robust when variations were introduced to the enrichment time, the volume for DNA extraction, and the heat block time (data not shown). PMID:25051633

  8. InstantLabs Listeria species food safety kit. Performance tested methods 041304.

    PubMed

    Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit

    2014-01-01

    The InstantLabs Listeria Species Food SafetyKitwas validated against the International Organization for Standardization (ISO) reference method 11290-1 for the detection of Listeria monocytogenes and other Listeria species. The matrixes (stainless steel, sealed concrete, cheddar cheese, raw shrimp, and hot dogs) were inoculated with approximately 1 CFU/test portion of various Listeria species to generate fractional positives (5-15) in 20 inoculated samples. Enrichments were also fractionally inoculated with L. monocytogenes for side-by-side testing of the InstantLabs Listeria monocytogenes Food Safety Kit. Stainless steel and sealed concrete samples were validated using 4 x 4" and 1 x 1" test areas, respectively, and enriched in Buffered Listeria Enrichment Broth (BLEB) at 35 +/- 1 degrees C for 22-28 h. All food samples were tested at 25 g or 25 mL and enriched in BLEB at 35 +/- 1 degrees C for 24-28 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of Listeria species on stainless steel, sealed concrete, cheddar cheese, raw shrimp, and hot dogs. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 80 Listeria species and 30 non-Listeria species examined. The method was shown to be robust when variations were introduced to the enrichment time, the volume for DNA extraction, and the heat block time (data not shown).

  9. Physico-chemical properties of instant ogbono (Irvingia gabonensis) mix powder

    PubMed Central

    Bamidele, Oluwaseun P; Ojedokun, Omotayo S; Fasogbon, Beatrice M

    2015-01-01

    The main objective of the research is to develop a recipe of instant dry soup mix for easy preparation of ogbono soup. Instant ogbono mix powder was processed using common locally ingredients. Dika kernel powder, dried ugwu leaf, crayfish, stock fish, and a mixture of locust bean, onion, seasoning and Cameroon powder were formulated at different ratios to find the best acceptable ogbono mix powder. The samples were subjected to proximate, functional, vitamin, mineral, and sensory analyses. The formulated sample D with the highest ratio of crayfish and stock fish had the highest value of protein and carbohydrate (24.13 and 35.61%, respectively). The control sample (100% dika kernel powder) was low in moisture content (6.20%) but high in crude fat, other samples followed in this order (control > A > B > C > D) for crude fat. Ash, crude fiber, and carbohydrate showed a significant difference (P < 0.05) in all the samples. The functional properties of the sample showed a significant difference (P < 0.05) in all the samples with the control having the highest value for the water absorption, swelling capacity, and bulk density which may be due to the high crude fiber and low moisture content recorded for the control sample in the proximate analysis. The mineral content of all the samples were higher than the control with phosphorous having the highest value and iron the least value. Vitamin C was the main dominating vitamin in the sample followed by vitamin B2, vitamin A, and vitamin B3. The sensory evaluation revealed that 100% dika kernel powder gave a good attribute of the soup but with less nutritional composition, while some formulated samples showed a similar attribute with higher nutritional value. Sample A with the highest overall acceptability had the best attribute of ogbono soup. Instant ogbono mix powder has higher nutritional value and easy to cook. PMID:26288723

  10. Trigonelline in coffee. II. Content of green, roasted and instant coffee.

    PubMed

    Stennert, A; Maier, H G

    1994-09-01

    The results of several determinations of trigonelline in green, roasted and instant coffees are reported. The values in normal coffee species and degrees of roast are in agreement with most literature values. In Coffea dewevrei var. excelsa and C. stenophylla lower values were found than reported in the only other publication. The differences from steamed samples were minimal. Fast roasting may result in higher values with the same organic roasting loss, but this was not observed in commercial blends. During industrial extraction of roasted coffee, trigonelline is not completely extracted. The percentage depends on the extraction yield. PMID:7975906

  11. Maps showing mineral resource potential of the Virgin Mountains Instant Study Area, Clark County, Nevada

    USGS Publications Warehouse

    Hose, Richard K.; Carlson, Robert R.; Federspiel, Francis E.; Huffsmith, James D.

    1981-01-01

    The Virgin Mountains Instant Study Area contains about 30,000 acres (12,000 ha) in southeastern Nevada. In accordance with the Federal Land Policy and Management Act (P.L. 94-579), the U.S. Bureau of Mines examined mines, prospects, and mineralized zones, and the U.S. Geological Survey made regional geologic, geophysical, and geochemical investigations. Tungsten and sheet mica have been produced from the study area, and oil and gas lease applications have been filed on 20,300 acres (8,200 ha). Sixteen mining claims are presently held. 

  12. Map showing mineral resource potential of the Paiute Instant (Primitive) Study Area, Mohave County, Arizona

    USGS Publications Warehouse

    Villalobos, Hector A.; Hamm, Louis W.

    1981-01-01

    Several areas in the Paiute Instant Study Area are judged to have at best a low mineral potential. These include areas of copper, lead, manganese, molybdenum, nickel, silver, tungsten, and zinc mineralization, as well as occurrences of dumortierite, beryllium, arsenic, barium, gypsum, gem minerals, sand, gravel, and limestone. The metallic deposits and dumortieri te, beryllium, and arsenic occur over small surface areas. Significant production has not resulted from mining activity in mineralized areas. Sand, gravel, limestone, gem minerals, gypsum, and barium occurrences are far from major markets. Currently, there are no active mining operations in the study area.

  13. Extraction of essential oils from Algerian myrtle leaves using instant controlled pressure drop technology.

    PubMed

    Berka-Zougali, Baya; Hassani, Aicha; Besombes, Colette; Allaf, Karim

    2010-10-01

    In the present work, the new extraction process of Détente Instantanée Contrôlée DIC (French, for instant controlled pressure drop) was studied, developed, quantitatively and qualitatively compared to the conventional hydrodistillation method for the extraction of essential oils from Algerian myrtle leaves. DIC was used as a thermomechanical treatment, DIC subjecting the product to a high-pressure saturated steam. The DIC cycle ends with an abrupt pressure drop towards vacuum, and this instantly leads to an autovaporization of myrtle volatile compounds. An immediate condensation in the vacuum tank produced a micro-emulsion of water and essential oils. Thus, an ultra-rapid cooling of residual leaves occurred, precluding any thermal degradation. An experimental protocol was designed with 3 independent variables: saturated steam pressure between 0.1 and 0.6 MPa, resulting in a temperature between 100 and 160°C, a total thermal processing time between 19 and 221 s, and between 2 and 6 DIC cycles. The essential oils yield was defined as the main dependent variable. This direct extraction gave high yields and high quality essential oil, as revealed by composition and antioxidant activity (results not shown). After this treatment, the myrtle leaves were recovered and hydrodistilled in order to quantify the essential oil content in residual DIC-treated samples. Scanning electron microscope (SEM) showed some modification of the structure with a slight destruction of cell walls after DIC treatment.

  14. Simplified multi-element analysis of ground and instant coffees by ICP-OES and FAAS.

    PubMed

    Szymczycha-Madeja, Anna; Welna, Maja; Pohl, Pawel

    2015-01-01

    A simplified alternative to the wet digestion sample preparation procedure for roasted ground and instant coffees has been developed and validated for the determination of different elements by inductively coupled plasma optical emission spectrometry (ICP-OES) (Al, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, Zn) and flame atomic absorption spectrometry (FAAS) (Ca, Fe, K, Mg, Na). The proposed procedure, i.e. the ultrasound-assisted solubilisation in aqua regia, is quite fast and simple, requires minimal use of reagents, and demonstrated good analytical performance, i.e. accuracy from -4.7% to 1.9%, precision within 0.5-8.6% and recovery in the range 93.5-103%. Detection limits of elements were from 0.086 ng ml(-1) (Sr) to 40 ng ml(-1) (Fe). A preliminary classification of 18 samples of ground and instant coffees was successfully made based on concentrations of selected elements and using principal component analysis and hierarchic cluster analysis.

  15. Tweeting in the Classroom: Instant feedback and assessment using a mobile web app

    NASA Astrophysics Data System (ADS)

    Saravanan, R.

    2011-12-01

    Cell phones with texting capabilities are ubiquitous in the college classroom, and smart phones are becoming increasingly common. These phones are used primarily for personal activities, including social networking, and are expected to remain switched off during instruction. The powerful communication capability of these devices, which could potentially facilitate novel forms of "instructional networking", remains untapped. Instead, special-purpose devices ("clickers") are used when instant feedback is desired in the classroom. A number of technical and behavioral challenges need to be overcome before mobile phones can be used routinely to assist in classroom instruction. This presentation will describe the experience of developing and deploying a mobile web app that enables students to provide instant feedback in the classroom using their mobile phones. The web app leverages existing social networking infrastructure, e.g., using the Twitter microblogging service to aggregate text messages sent by students, to promote classroom interaction. The web app was deployed both in a regular lecture hall and in a computer lab. Topics to be discussed include the technical challenges of deploying a mobile web app in a classroom setting, such as internet accessibility and latency, as well as non-technical issues relating to privacy, student reactions, etc.

  16. Parameterization of SURFEX-TOPMODEL river velocity based on instant discharge dependency

    NASA Astrophysics Data System (ADS)

    Nedkov, Nikolay; Artinyan, Eram; Tsarev, Petko

    2016-04-01

    SURFEX-TOPMODEL distributed physical model is used to analyze and forecast stream flow discharges including flash floods occurring in a Mediterranean river basin in Bulgaria. River velocity is one of the parameters that need to be calibrated in order to achieve acceptable representation of peak floods but in the same time to produce a smooth hydrograph during the low flow periods. The coupled model showed great sensibility to the parameter but when focusing to reproduce high peaks low discharge hydrograph presented unrealistic small peaks too. The dependency between the measured instant discharge and mean section velocity was established for the Bulgarian hydrometric stations on rivers using 20 years of direct discharge-velocity measures of the National Institute of Meteorology and Hydrology of Bulgaria. The relationship is used to avoid the calibration of the velocity parameter for the measured cross-sections. It was coded within the model thus permitting dynamical adjustment of the velocity with respect to the computed instant discharge in the river section. We present the results of river flow simulations with the modified parameterization compared to those with the original model for the hydrological year 2014-2015. Keywords: SURFEX-TOP, river speed parameter

  17. Optimization of instant dalia dessert pre-mix production by using response surface methodology.

    PubMed

    Jha, Alok; Shalini, B N; Patel, Ashok Ambalal; Singh, Mithilesh; Rasane, Prasad

    2015-02-01

    Dalia, a wheat-based, particulate containing dairy dessert is popularly consumed as a breakfast food and is also considered as a health food. Though popular throughout Northern parts of the country, its limited shelf-life even under refrigeration imposes severe restrictions on its organized manufacture and marketing. In order to promote dalia dessert as a marketable product, in the present study, a process was developed for manufacture of instant dalia pre-mix, as a dry product with long shelf-life, which could be attractively packaged and easily reconstituted for consumption. During the investigation, the effect of different levels of milk solids and wheat solids was studied on dalia pre-mix quality by employing a central composite rotatable design (CCRD). The suggested formulation had 17.82 % milk solids and 2.87 % wheat solids. This formulation was found to be most appropriate for manufacture of instant dalia pre-mix with predicted sensory scores (Max. 100) of 85.35, 41.98 and 67.27 for mouthfeel, consistency and flavor, respectively; the viscosity of the product was 941.0 cp.

  18. Minimizing the instant and accumulative effects of salt permeability to sustain ultrahigh osmotic power density.

    PubMed

    Zhang, Sui; Chung, Tai-Shung

    2013-09-01

    We have investigated the instant and accumulative effects of salt permeability on the sustainability of high power density in the pressure-retarded osmosis (PRO) process experimentally and theoretically. Thin-film composite (TFC) hollow-fiber membranes were prepared. A critical wall thickness was observed to ensure sufficient mechanical stability and hence a low salt permeability, B. The experimental results revealed that a lower B was essential to enhance the maximum power density from 15.3 W/m(2) to as high as 24.3 W/m(2) when 1 M NaCl and deionized water were feeds. Modeling work showed that a large B not only causes an instant drop in the initial water flux but also accelerates the flux decline at high hydraulic pressures, leading to reduced optimal operating pressure and maximal power density. However, the optimal operating pressure to harvest energy can be greater than one-half of the osmotic pressure gradient across the membrane if one can carefully design a PRO membrane with a large water permeability, small B value, and reasonably small structural parameter. It was also found that a high B accumulates salts in the feed, leads to the oversalinization of the feed, and largely lowers both the water flux and power density along the membrane module. Therefore, a low salt permeability is highly desirable to sustain high power density not only locally but also throughout the whole module.

  19. Switching to instant black coffee modulates sodium selenite-induced cataract in rats.

    PubMed

    El Okda, E A; Mohamed, M M; Shaheed, E B; Abdel-Moemin, A R

    2016-01-01

    The influence of daily consumption of some common beverages on the development of cataract in rats was investigated. Total phenol content was determined in the beverages and an oral standardized dose of total phenols from each beverage was given to the treated rats. Weaned male albino rats were used and divided into five groups (n=7). Rats were fed Ain 93G and administered the standardized dose of instant coffee, black tea and hibiscus beverages for 30 days. On day 14 all rats were injected with a single dose of sodium selenite (Na2SeO3) 15 µmol/kg bodyweight, except the control groups NC (negative control, did not receive Na2SeO3) and PC (positive control, was already injected on day 1 of the study). The rats were continued on Ain 93G and the standardized dose for another 16 days. Positive control rats were used. Total phenols were 210, 40, and 44 mg/g dry weight gallic acid equivalent in black coffee, black tea, and hibiscus, respectively. Decreased levels (statistically significant P<0.05) of malondialdehyde, total nitric oxide, Ca-ATPase, tumor necrosis factor-α, interleukin-1β, superoxide dismutase, and conversely, increased levels (statistically significant P<0.05) of total protein, reduced glutathione, catalase were found in the lenses of the coffee group compared to PC. There are co-phenol substances in the instant black coffee that promoted coffee to be the most effective beverage. PMID:27158251

  20. Optimization of instant dalia dessert pre-mix production by using response surface methodology.

    PubMed

    Jha, Alok; Shalini, B N; Patel, Ashok Ambalal; Singh, Mithilesh; Rasane, Prasad

    2015-02-01

    Dalia, a wheat-based, particulate containing dairy dessert is popularly consumed as a breakfast food and is also considered as a health food. Though popular throughout Northern parts of the country, its limited shelf-life even under refrigeration imposes severe restrictions on its organized manufacture and marketing. In order to promote dalia dessert as a marketable product, in the present study, a process was developed for manufacture of instant dalia pre-mix, as a dry product with long shelf-life, which could be attractively packaged and easily reconstituted for consumption. During the investigation, the effect of different levels of milk solids and wheat solids was studied on dalia pre-mix quality by employing a central composite rotatable design (CCRD). The suggested formulation had 17.82 % milk solids and 2.87 % wheat solids. This formulation was found to be most appropriate for manufacture of instant dalia pre-mix with predicted sensory scores (Max. 100) of 85.35, 41.98 and 67.27 for mouthfeel, consistency and flavor, respectively; the viscosity of the product was 941.0 cp. PMID:25694701

  1. Amplified impedimetric immunosensor based on instant catalyst for sensitive determination of ochratoxin A.

    PubMed

    Tang, Juan; Huang, Yapei; Zhang, Cengceng; Liu, Huiqiong; Tang, Dianping

    2016-12-15

    A new impedimetric immunosensor for the fast determination of ochratoxin A (OTA) in food samples was developed based on the instant catalyst as enhancer. Initially, the signal tags were prepared via co-immobilization of anti-OTA antibody and amine-terminated dendrimer (PAMAM) on the graphene oxide nanosheets through the covalent interaction, which were utilized as a good platform for combining manganese ion (anti-OTA-GO-PAMAM-Mn(2+)). Upon target OTA introduction, a competitive-type immunoreaction was implemented between the analyte and the immobilized OTA-BSA on the electrode for the anti-OTA antibody on the graphene oxide nanosheets labels. After a competitive immunoassay format, the anti-OTA-GO-PAMAM-Mn(2+) were captured onto the electrode surface, which could induce the in situ formation of MnO2via classical redox reaction between Mn(2+) and KMnO4 on the immunesensing platform. Moreover, the generated MnO2 nanoparticles act as efficient catalyst could catalyze the 4-chloro-1-naphthol (4-CN) oxidation without H2O2 to generate an insoluble precipitation on the platform. Under the optimal conditions, the instant catalyst based impedimetric immunosensor displayed a wide dynamic working range between 0.1pgmL(-1) and 30ngmL(-1). The detection limit (LOD) of the assay was 0.055pgmL(-1). The developed method exhibited high selectivity and can be used for the determination of OTA in real red wine samples. PMID:27419906

  2. Deaf and hard of hearing Americans' instant messaging and e-mail use: a national survey.

    PubMed

    Bowe, Frank G

    2002-10-01

    An online survey of 884 deaf and hard of hearing adults asked about their current and past use of communication technologies, notably TTY, telecommunications relay services, e-mail, and instant messaging (IM). Results showed that respondents were using e-mail and IM far more than TTY and relay services. The study participants virtually all had e-mail and IM at home. In fact, about one quarter had a high-speed ("broadband") connection at home. While the vast majority also had and used e-mail at work, just 1 in 3 had IM at his or her place of employment. The findings have several implications. Most important for educators is that strong reading and writing skills are essential if adults who are deaf or hard of hearing are to take advantage of today's communications technologies. Another conclusion is that some workers who are deaf or hard of hearing appear to face discrimination in employment because office policies forbid the use of a highly effective reasonable accommodation, instant messaging.

  3. Effects on serum lipids of adding instant oats to usual American diets.

    PubMed Central

    Van Horn, L; Moag-Stahlberg, A; Liu, K A; Ballew, C; Ruth, K; Hughes, R; Stamler, J

    1991-01-01

    This study was designed as a test of the serum lipid response and dietary adaptation to recommended daily inclusion of instant oats in an otherwise regular diet. Hypercholesterolemic adults were randomly assigned to a control or intervention group. Participants in the intervention group were given packages of instant oats and requested to eat two servings per day (approximately two ounces dry weight), substituting the oats for other carbohydrate foods in order to maintain baseline calorie intake and keep weight stable. Serum lipids were measured in blood collected by venipuncture at baseline, four weeks, and eight weeks. Baseline mean total cholesterol (TC) levels were 6.56 mmol/L and 6.39 mmol/L for intervention and control groups, respectively. After eight weeks, mean serum total cholesterol of the intervention group was lower by -0.40 mmol/L, and mean net difference in TC between the two groups was 0.32 mmol/L (95% CI: 0.09, 0.54). Low-density lipoprotein-cholesterol was similarly reduced with mean net difference of 0.25 mmol/L (95% CI: 0.02, 0.48) between the two groups. Mean soluble fiber intake increased along with slight self-imposed reductions in mean total fat, saturated fat, and dietary cholesterol intake in the intervention group. Neither group changed mean body weight. Daily inclusion of two ounces of oats appeared to facilitate reduction of serum total cholesterol and LDL-C in these hyperlipidemic individuals. PMID:1846723

  4. Amplified impedimetric immunosensor based on instant catalyst for sensitive determination of ochratoxin A.

    PubMed

    Tang, Juan; Huang, Yapei; Zhang, Cengceng; Liu, Huiqiong; Tang, Dianping

    2016-12-15

    A new impedimetric immunosensor for the fast determination of ochratoxin A (OTA) in food samples was developed based on the instant catalyst as enhancer. Initially, the signal tags were prepared via co-immobilization of anti-OTA antibody and amine-terminated dendrimer (PAMAM) on the graphene oxide nanosheets through the covalent interaction, which were utilized as a good platform for combining manganese ion (anti-OTA-GO-PAMAM-Mn(2+)). Upon target OTA introduction, a competitive-type immunoreaction was implemented between the analyte and the immobilized OTA-BSA on the electrode for the anti-OTA antibody on the graphene oxide nanosheets labels. After a competitive immunoassay format, the anti-OTA-GO-PAMAM-Mn(2+) were captured onto the electrode surface, which could induce the in situ formation of MnO2via classical redox reaction between Mn(2+) and KMnO4 on the immunesensing platform. Moreover, the generated MnO2 nanoparticles act as efficient catalyst could catalyze the 4-chloro-1-naphthol (4-CN) oxidation without H2O2 to generate an insoluble precipitation on the platform. Under the optimal conditions, the instant catalyst based impedimetric immunosensor displayed a wide dynamic working range between 0.1pgmL(-1) and 30ngmL(-1). The detection limit (LOD) of the assay was 0.055pgmL(-1). The developed method exhibited high selectivity and can be used for the determination of OTA in real red wine samples.

  5. InstantLabs® E. coli O157 Food Safety Kit.

    PubMed

    Sharma, Neil; Bambusch, Lauren; Upadhyay, Apala; Le, Thu; Lopez, Chris; Brahmanda, Bharath

    2015-01-01

    The InstantLabs® E. coli O157 Food Safety Kit was validated against the International Organization for Standardization reference method 16654 for the detection of Escherichia coli O157. The matrixes, raw ground beef, raw beef trim, Romaine lettuce, pasteurized apple juice, and raw ground chicken, were inoculated with appropriate CFU/test portion of E. coli O157 to generate fractional positives (5-15) in 20 inoculated samples. The matrixes were co-inoculated with Salmonella at 2-5 times the level of E. coli O157 to demonstrate the potential for using the same enrichment culture for the detection of multiple organisms. Samples were enriched in prewarmed FASTGRO SE broth at 42±1°C for 10-20 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of E. coli O157 in all tested samples. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 E. coli O157 serovars and 30 non-E. coli O157 species examined. Finally, the method was shown to be robust when variations were applied to enrichment time, volume for DNA extraction, and heat block time.

  6. Switching to instant black coffee modulates sodium selenite-induced cataract in rats

    PubMed Central

    El Okda, E. A.; Mohamed, M. M.; Shaheed, E. B.; Abdel-Moemin, A. R.

    2016-01-01

    The influence of daily consumption of some common beverages on the development of cataract in rats was investigated. Total phenol content was determined in the beverages and an oral standardized dose of total phenols from each beverage was given to the treated rats. Weaned male albino rats were used and divided into five groups (n=7). Rats were fed Ain 93G and administered the standardized dose of instant coffee, black tea and hibiscus beverages for 30 days. On day 14 all rats were injected with a single dose of sodium selenite (Na2SeO3) 15 µmol/kg bodyweight, except the control groups NC (negative control, did not receive Na2SeO3) and PC (positive control, was already injected on day 1 of the study). The rats were continued on Ain 93G and the standardized dose for another 16 days. Positive control rats were used. Total phenols were 210, 40, and 44 mg/g dry weight gallic acid equivalent in black coffee, black tea, and hibiscus, respectively. Decreased levels (statistically significant P<0.05) of malondialdehyde, total nitric oxide, Ca-ATPase, tumor necrosis factor-α, interleukin-1β, superoxide dismutase, and conversely, increased levels (statistically significant P<0.05) of total protein, reduced glutathione, catalase were found in the lenses of the coffee group compared to PC. There are co-phenol substances in the instant black coffee that promoted coffee to be the most effective beverage. PMID:27158251

  7. Geophysical wave tomography

    NASA Astrophysics Data System (ADS)

    Zhou, Chaoguang

    2000-11-01

    This study is concerned with geophysical wave tomography techniques that include advanced diffraction tomography, traveltime calculation techniques and simultaneous attenuation and velocity tomography approaches. We propose the source independent approximation, the Modified Quasi-Linear approximation and develop a fast and accurate diffraction tomography algorithm that uses this approximation. Since the Modified Quasi-Linear approximation accounts for the scattering fields within scatterers, this tomography algorithm produces better image quality than conventional Born approximation tomography algorithm does with or without the presence of multiple scatterers and can be used to reconstruct images of high contrast objects. Since iteration is not required, this algorithm is efficient. We improve the finite difference traveltime calculation algorithm proposed by Vidale (1990). The bucket theory is utilized in order to enhance the sorting efficiency, which accounts for about ten percent computing time improvement for large velocity models. Snell's law is employed to solve the causality problem analytically, which enables the modified algorithm to compute traveltimes accurately and rapidly for high velocity contrast media. We also develop two simultaneous attenuation and velocity tomography approaches, which use traveltimes and amplitude spectra of the observed data, and discuss some of their applications. One approach is processing geophysical data that come from one single survey and the other deals with the repeated survey cases. These approaches are nonlinear and therefore more accurate than linear tomography. A linear system for wave propagation and constant-Q media are assumed in order to develop the tomography algorithms. These approaches not only produce attenuation and velocity images at the same time but also can be used to infer the physical rock properties, such as the dielectric permittivity, the electric conductivity, and the porosity. A crosshole radar

  8. The impact of an instant pregnancy test kit on the operations of a major hospital casualty department.

    PubMed

    Baber, R J; Bonifacio, M; Saunders, D M

    1988-05-01

    The records of all patients on whom a casualty department pregnancy test was performed during the first 4 months of 1986 were retrospectively examined and compared with the records of all patients who in the first 4 months of 1987 had had an instant pregnancy test performed in the same casualty department, to determine the impact of such a kit on diagnostic accuracy, operative procedures and related economic factors. It was demonstrated that instant pregnancy testing significantly improved the accuracy of provisional diagnoses and appeared to help in reducing the number of surgical procedures performed. Furthermore, it was shown that a combination of careful clinical assessment plus the appropriate application of an instant pregnancy test kit could result in a cost saving to the hospital of over $41,000 per annum. PMID:2976273

  9. A new method for combining live action and computer graphics in stereoscopic 3D

    NASA Astrophysics Data System (ADS)

    Rupkalvis, John A.; Gillen, Ron

    2008-02-01

    A primary requirement when elements are to be combined stereoscopically, is that homologous points in each eye view of each element have identical parallax separation at any point of interaction. If this is not done, the image parts on one element will appear to be at a different distance from the corresponding or associated parts on the other element. This results in a visual discontinuity that appears very unnatural. For example, if a live actor were to appear to "shake hands" with a cartoon character, a very natural appearing juncture may appear to be the case when seen in 2-D, but their hands may appear to miss when seen in 3-D. Previous efforts to compensate, or correct these errors have involved painstaking time-consuming trial-and-error tests. In the area of pure animation, efforts to make cartoon characters appear more realistic were developed. A "motion tracking" technique was developed. This involves an actor wearing a special suit with indicator marks at various points on their body. The actor walks through the scene, then the animator tracks the points using motion capture software. Because live action and CG elements can interact or change at several different points and levels within a scene, additional requirements must also be addressed. "Occlusions" occur when one object passes in front of another. A particular tracking point may appear in one eye-view, and not the other. When Z-axis differentials are to be considered in the live action as well as the CG elements, and both are to interact with each other, both eye-views must be tracked, especially at points of occlusion. A new approach would be to generate a three dimensional grid, within which the action is to take place. This grid can be projected, onto the stage where the live action part is to take place. When differential occlusions occur, the grid may be seen and CG elements plotted in reference to it. Because of the capability of precisely locating points in a digital image, a pixel

  10. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy.

    PubMed

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  11. Computed Tomography (CT) -- Head

    MedlinePlus

    ... further information please consult the ACR Manual on Contrast Media and its references. The risk of serious allergic ... Angiography (CTA) Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, ...

  12. Computed Tomography (CT) -- Sinuses

    MedlinePlus

    ... further information please consult the ACR Manual on Contrast Media and its references. The risk of serious allergic ... X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - Sinuses About ...

  13. Stereoscopic three-dimensional display based on polarization-switching device with low cross talk and high contrast ratio.

    PubMed

    Shin, Hun Ki; Lee, Joong Ha; Jin, Hye-Jung; Yoon, Tae-Hoon; Kim, Jae Chang

    2010-07-01

    We present a polarization-switching device with dual-frequency liquid crystal material for a stereoscopic three-dimensional (3D) display. This device shows good properties, such as low 3D cross talk and high brightness, due to a fast dynamic response time. Without optical compensation, however, this device has an asymmetric contrast ratio on the left- and right-hand sides of 3D glasses, because the viewing principles on both sides are different from each other. To solve this problem, we design an optical structure with two half-wave plate films using the Jones matrix method. As the results of simulation and experiment show, excellent dark states and high brightness are realized over the entire range of visible wavelengths on both sides.

  14. Geometric and Reflectance Signature Characterization of Complex Canopies Using Hyperspectral Stereoscopic Images from Uav and Terrestrial Platforms

    NASA Astrophysics Data System (ADS)

    Honkavaara, E.; Hakala, T.; Nevalainen, O.; Viljanen, N.; Rosnell, T.; Khoramshahi, E.; Näsi, R.; Oliveira, R.; Tommaselli, A.

    2016-06-01

    Light-weight hyperspectral frame cameras represent novel developments in remote sensing technology. With frame camera technology, when capturing images with stereoscopic overlaps, it is possible to derive 3D hyperspectral reflectance information and 3D geometric data of targets of interest, which enables detailed geometric and radiometric characterization of the object. These technologies are expected to provide efficient tools in various environmental remote sensing applications, such as canopy classification, canopy stress analysis, precision agriculture, and urban material classification. Furthermore, these data sets enable advanced quantitative, physical based retrieval of biophysical and biochemical parameters by model inversion technologies. Objective of this investigation was to study the aspects of capturing hyperspectral reflectance data from unmanned airborne vehicle (UAV) and terrestrial platform with novel hyperspectral frame cameras in complex, forested environment.

  15. Stereoscopic direction finding analysis of a type III solar radio burst - Evidence for emission at 2f/p-/

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.; Baumback, M. M.; Rosenbauer, H.

    1978-01-01

    Stereoscopic direction finding measurements from the Imp 8, Hawkeye 1, and Helios 2 spacecraft over base line distances of a substantial fraction of an astronomical unit are used to directly determine the three-dimensional trajectory of a type III solar radio burst. By comparing the observed source positions with the direct in situ solar wind plasma density measurements obtained by Helios 1 and 2 near the sun, the relationship of the emission frequency to the local plasma frequency can be determined directly without any modeling assumptions. These comparisons show that the type III radio emission occurs near the second harmonic of the local electron plasma frequency. Other characteristics of the type III radio emission, such as the source size, which can be obtained from this type of analysis, are also discussed.

  16. Stereoscopic three-dimensional display based on polarization-switching device with low cross talk and high contrast ratio.

    PubMed

    Shin, Hun Ki; Lee, Joong Ha; Jin, Hye-Jung; Yoon, Tae-Hoon; Kim, Jae Chang

    2010-07-01

    We present a polarization-switching device with dual-frequency liquid crystal material for a stereoscopic three-dimensional (3D) display. This device shows good properties, such as low 3D cross talk and high brightness, due to a fast dynamic response time. Without optical compensation, however, this device has an asymmetric contrast ratio on the left- and right-hand sides of 3D glasses, because the viewing principles on both sides are different from each other. To solve this problem, we design an optical structure with two half-wave plate films using the Jones matrix method. As the results of simulation and experiment show, excellent dark states and high brightness are realized over the entire range of visible wavelengths on both sides. PMID:20596202

  17. Flame four-dimensional deflection tomography with compressed-sensing-revision reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Zhao, Minmin; Liu, Zhigang; Wu, Zhaohang

    2016-08-01

    Deflection tomography with limited angle projections was investigated to visualize a premixed flame. A projection sampling system for deflection tomography was used to obtain chronological deflectogram arrays at six view angles with only a pair of gratings. A new iterative reconstruction algorithm with deflection angle compressed-sensing revision was developed to improve reconstruction-distribution quality from incomplete projection data. Numerical simulation and error analysis provided a good indication of algorithm precision and convergence. In the experiment, 150 fringes were processed, and temperature distributions in 20 cross-sections were reconstructed from projection data in four instants. Four-dimensional flame structures and temperature distributions in the flame interior were visualized using the visualization toolkit. The experimental reconstruction was then compared with the result obtained from computational fluid dynamic analysis.

  18. Relativistic quantum mechanics and relativistic entanglement in the rest-frame instant form of dynamics

    SciTech Connect

    Alba, David; Crater, Horace W.; Lusanna, Luca

    2011-06-15

    A new formulation of relativistic quantum mechanics is proposed in the framework of the rest-frame instant form of dynamics, where the world-lines of the particles are parametrized in terms of the Fokker-Pryce center of inertia and of Wigner-covariant relative 3-coordinates inside the instantaneous Wigner 3-spaces, and where there is a decoupled (non-covariant and non-local) canonical relativistic center of mass. This approach: (a) allows us to make a consistent quantization in every inertial frame; (b) leads to a description of both bound and scattering states; (c) offers new insights on the relativistic localization problem; (d) leads to a non-relativistic limit with a Hamilton-Jacobi treatment of the Newton center of mass; (e) clarifies non-local aspects (spatial non-separability) of relativistic entanglement connected with Lorentz signature and not present in its non-relativistic treatment.

  19. Physicochemical characterization of wet microalgal cells disrupted with instant catapult steam explosion for lipid extraction.

    PubMed

    Cheng, Jun; Huang, Rui; Li, Tao; Zhou, Junhu; Cen, Kefa

    2015-09-01

    Instant catapult steam explosion (ICSE) was employed to disrupt wet microalgal cells for efficient lipid extraction. Physicochemical properties of exploded cells were investigated through SEM, TEM, FTIR, and TGA. The exploded cells increased in fractal dimension (1.53-1.65) when preheat time was prolonged from 0 min to 5 min and in surface pore area when steam pressure was increased. Meanwhile, the exploded cells decreased in mean size (1.69-1.44 μm) when the filling ratio of wet microalgal biomass in the preheat chamber decreased (75-12.5%). Flash evaporation and volume expansion exploded the cell walls and released the cytoplasm of the microalgal cells. These phenomena decreased the carbohydrate content and increased the lipid content in the exploded biomass. However, ICSE treatment did not change the lipid compositions in the microalgal cells. Using isopropanol as a cosolvent significantly increased the yield of lipids extracted with hexane from the exploded wet microalgal biomass.

  20. Assessment and regression analysis on instant catapult steam explosion pretreatment of corn stover.

    PubMed

    Liu, Chen-Guang; Liu, Li-Yang; Zi, Li-Han; Zhao, Xin-Qing; Xu, You-Hai; Bai, Feng-Wu

    2014-08-01

    Instant catapult steam explosion (ICSE) offers enormous physical force on lignocellulosic biomass due to its extremely short depressure duration. In this article, the response surface methodology was applied to optimize the effect of working parameters including pressure, maintaining time and mass loading on the crystallinity index and glucose yield of the pretreated corn stover. It was found that the pressure was of essential importance, which determined the physical force that led to the morphological changes without significant chemical reactions, and on the other hand the maintaining time mainly contributed to the thermo-chemical reactions. Furthermore, the pretreated biomass was assessed by scanning electron microscope, X-ray diffraction and Fourier transform infrared spectra to understand mechanisms underlying the ICSE pretreatment.

  1. InstantLabs Listeria monocytogenes food safety kit. Performance tested method 051304.

    PubMed

    Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit

    2014-01-01

    The InstantLabs Listeria monocytogenes Food Safety Kit was validated against the International Organization for Standardization (ISO) reference method 11290-1 for the detection of Listeria monocytogenes and other Listeria species. The matrixes (stainless steel, sealed concrete, ice cream, whole milk, cheddar cheese, raw shrimp, hot dogs, deli turkey, and lettuce) were inoculated with approximately 1 CFU/test portion of L. monocytogenes to generate fractional positives (5-15) in 20 inoculated samples. Enrichments were also fractionally inoculated with L. grayii for side-by-side testing of the Listeria Species Food Safety Kit. Stainless steel and sealed concrete samples were validated using 4 x 4" and 1 x 1 " test areas, respectively, and enriched in Buffered Listeria Enrichment Broth (BLEB) at 35 +/- 1degreesC for 22-28 h. All food samples were tested at 25 g and enriched in BLEB at 35 +/- 1 degreesC for 24-28 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of L. monocytogenes on stainless steel and sealed concrete and in ice cream, whole milk, cheddar cheese, raw shrimp, hot dogs, deli turkey, and lettuce. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 L. monocytogenes serovars and 30 non-L. monocytogenes species examined. The method was shown to be robust when the enrichment times, volumes for DNA extraction, and heat block times were varied. PMID:25051634

  2. A Simple Instant-Estimation Method for Time-Average Quantities of Single-Phase Power and Application to Single-Phase Power Grid Connection by Inverter

    NASA Astrophysics Data System (ADS)

    Shinnaka, Shinji

    This paper presents and analyzes a new simple instant-estimation method for time-average quantities such as rms-values of voltage and current, active and reactive powers, and power factor for single-phase power with the fundamental component of constant or nearly-constant frequency by measuring instantaneous values of voltage and current. According to the analyses, the method can instantly estimate time average values with accuracy of the fundamental frequency, and estimation accuracy of power factor is about two times better than that of voltage, current, and powers. The instant-estimation method is simple and can be easily applied to single-phase power control systems that are expected to control instantly and continuously power factor on a single-phase grid by inverter. Based on the proposed instant-estimation method, two-methods for such power control systems are also proposed and their usefulness is verified through simulations.

  3. Crowdsourcing oriented Ontology Applies in Instant Debris-flow Disaster Information Platform in Web and Smart Phone Application

    NASA Astrophysics Data System (ADS)

    Tsai, Yuan-Fan; Chan, Chun-Hsiang; Huang, Chu-Yi; Chou, Huan-Chieh

    2015-04-01

    In recent years, extreme climates events increase the frequency of typhoon and rainstorm, and this induces more natural disasters in Taiwan, such as flood and landsides. Thus, disaster reduction has become a dispensable issue in present government policy. However, most of people cannot obtain the latest disaster information, thus causing second disaster, on these reasons above, this study attempts to build an interface which provides instant disaster information. The proposal of study aims at establishing an instant information platform for debris flow disaster both on website and smart phone application, which combines crowdsourcing concepts and official open data through sending SMS, email notifications, disaster map and news to people. In addition, both website and smart phone application will not only automatically deliver official warning information, but also sending other disaster information uploaded by other people. However, the quality of crowdsourcing-based information is difficult to control, hence, this study utilizes three types validation method: one is instant rainfall information, another is potential region of debris flow disaster from ontology analysis, and the other is people mutual validation to maintain information quality. To sum up, this study has successfully established an instant information platform for debris flow disaster on website and smart phone application, and this provides the latest official and uploaded disaster information to reach disaster reduction, even for disaster prevention in the future. Keywords: Crowdsourcing-based Information, Disaster Ontology, Debris-flow Disaster

  4. 40 CFR 723.175 - Chemical substances used in or for the manufacture or processing of instant photographic and peel...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Act (15 U.S.C. 2604). (8) The term instant photographic film article means a self-developing... unreasonable burden or cost. (11) The term peel-apart film article means a self-developing photographic film... contaminants, as described in 29 CFR 1910.134. Selection of an appropriate respirator must be made according...

  5. 40 CFR 723.175 - Chemical substances used in or for the manufacture or processing of instant photographic and peel...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Act (15 U.S.C. 2604). (8) The term instant photographic film article means a self-developing... unreasonable burden or cost. (11) The term peel-apart film article means a self-developing photographic film... contaminants, as described in 29 CFR 1910.134. Selection of an appropriate respirator must be made according...

  6. 40 CFR 723.175 - Chemical substances used in or for the manufacture or processing of instant photographic and peel...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Act (15 U.S.C. 2604). (8) The term instant photographic film article means a self-developing... unreasonable burden or cost. (11) The term peel-apart film article means a self-developing photographic film... contaminants, as described in 29 CFR 1910.134. Selection of an appropriate respirator must be made according...

  7. PowerON: The use of instant message counseling and the Internet to facilitate HIV/STD education and prevention

    PubMed Central

    Moskowitz, David A.; Melton, Dan; Owczarzak, Jill

    2015-01-01

    Objective In recent years, Internet-based or online counseling has emerged as an effective way to assess psychological disorders and discuss destructive behaviors with individuals or groups of individuals. This study explores the application of online counseling to HIV/STD risk-taking behavior among men who have sex with men (MSM). Methods PowerON, an organization that provides sexual health information to MSM exclusively online, used instant message technology to counsel MSM in real time through computer-mediated means. A sample of 279 transcripts of instant message exchanges between PowerON counselors and Gay.com users were recorded and qualitatively analyzed. Results Approximately 43% of the instant message sessions discussed information about HIV/STD testing. Risk-taking behaviors were addressed in 39% of the sessions. Information about HIV/STDs and general counseling were given in 23% and 18% of the counseling sessions respectively. Conclusion The data showed these instant message sessions to be a potentially feasible forum for HIV/STD counseling. Practice Implications Information ordinarily disseminated at health clinics could be successfully distributed through the Internet to MSM. PMID:19217742

  8. Multiliteracies on Instant Messaging in Negotiating Local, Translocal, and Transnational Affiliations: A Case of an Adolescent Immigrant

    ERIC Educational Resources Information Center

    Lam, Wan Shun Eva

    2009-01-01

    Through an in-depth case study of the instant messaging practices of an adolescent girl who had migrated to the United States from China, this qualitative investigation examines the development of multiliteracies in the context of transnational migration and new media of communication. Data consisted of screen recordings of the youth's digital…

  9. Merging the Power of the Computer and VCR: Interactive Videotape with the Mandell Instant-Active Interface.

    ERIC Educational Resources Information Center

    Brown, Scott W.

    1991-01-01

    Describes the Mandell Instant-Active Device, a microcomputer-based system that enables teachers to add questions and/or statement prompts to an existing videotape without affecting the videotape itself. Applications, procedures, student feedback, and hardware requirements are discussed. Ordering information is included. (MES)

  10. A Context-Aware Ubiquitous Learning Approach for Providing Instant Learning Support in Personal Computer Assembly Activities

    ERIC Educational Resources Information Center

    Hsu, Ching-Kun; Hwang, Gwo-Jen

    2014-01-01

    Personal computer assembly courses have been recognized as being essential in helping students understand computer structure as well as the functionality of each computer component. In this study, a context-aware ubiquitous learning approach is proposed for providing instant assistance to individual students in the learning activity of a…

  11. Interaction Involvement in Cross-Culture Computer-Mediated Communication: Examination of a Communication Process in Dyadic Instant Messaging Conversations

    ERIC Educational Resources Information Center

    Nguyen, Thi Thao Duyen

    2013-01-01

    This dissertation explores how participants express and interpret verbal cues of interaction involvement in dyadic conversations via text-based Instant Messaging (IM). Moreover, it seeks to discover differences in the way American participants and Chinese participants use verbal cues when they are highly, or lowly involved. Based on previous…

  12. Coding into the Great Unknown: Analyzing Instant Messaging Session Transcripts to Identify User Behaviors and Measure Quality of Service

    ERIC Educational Resources Information Center

    Maximiek, Sarah; Rushton, Erin; Brown, Elizabeth

    2010-01-01

    After one year of providing virtual reference service through an instant messaging (IM) service, Binghamton University (BU) Libraries, under the purview of its Digital Reference Committee (DRC), undertook a study of collected session transcripts. The goals of this work were to determine who was using the IM service and why; if staffing for the…

  13. Informal Math Coaching by Instant Messaging: Two Case Studies of How University Students Coach K-12 Students

    ERIC Educational Resources Information Center

    Hrastinski, Stefan; Edman, Anneli; Andersson, Fredrik; Kawnine, Tanvir; Soames, Carol-Ann

    2014-01-01

    The aim of this study is to describe and explore how instant messaging (IM) can be used to support informal math coaching. We have studied two projects where university students use IM to coach K-12 students in mathematics. The coaches were interviewed with a focus on how informal coaching works by examining coaching challenges, how coaching can…

  14. Using Mobile Instant Messaging to Leverage Learner Participation and Transform Pedagogy at a South African University of Technology

    ERIC Educational Resources Information Center

    Rambe, Patient; Bere, Aaron

    2013-01-01

    One of the most complicated academic endeavours in transmission pedagogies is to generate democratic participation of all students and public expression of silenced voices. While the potential of mobile phones, particularly mobile instant messaging (MIM), to trigger broadened academic participation is increasingly acknowledged in literature,…

  15. Method comparison of automated matching software-assisted cone-beam CT and stereoscopic kilovoltage x-ray positional verification image-guided radiation therapy for head and neck cancer: a prospective analysis

    NASA Astrophysics Data System (ADS)

    Fuller, Clifton D.; Scarbrough, Todd J.; Sonke, Jan-Jakob; Rasch, Coen R. N.; Choi, Mehee; Ting, Joe Y.; Wang, Samuel J.; Papanikolaou, Niko; Rosenthal, David I.

    2009-12-01

    We sought to characterize interchangeability and agreement between cone-beam computed tomography (CBCT) and digital stereoscopic kV x-ray (KVX) acquisition, two methods of isocenter positional verification currently used for IGRT of head and neck cancers (HNC). A cohort of 33 patients were near-simultaneously imaged by in-room KVX and CBCT. KVX and CBCT shifts were suggested using manufacturer software for the lateral (X), vertical (Y) and longitudinal (Z) dimensions. Intra-method repeatability, systematic and random error components were calculated for each imaging modality, as were recipe-based PTV expansion margins. Inter-method agreement in each axis was compared using limits of agreement (LOA) methodology, concordance analysis and orthogonal regression. 100 daily positional assessments were performed before daily therapy in 33 patients with head and neck cancer. Systematic error was greater for CBCT in all axes, with larger random error components in the Y- and Z-axis. Repeatability ranged from 9 to 14 mm for all axes, with CBCT showing greater repeatability in 2/3 axes. LOA showed paired shifts to agree 95% of the time within ±11.3 mm in the X-axis, ±9.4 mm in the Y-axis and ±5.5 mm in the Z-axis. Concordance ranged from 'mediocre' to 'satisfactory'. Proportional bias was noted between paired X- and Z-axis measures, with a constant bias component in the Z-axis. Our data suggest non-negligible differences in software-derived CBCT and KVX image-guided directional shifts using formal method comparison statistics. A correction was made to the first line of page 7404 of this article on 26 November 2009. The corrected electronic version is identical to the print version.

  16. Stereoscopy and Tomography of Coronal Structures

    NASA Astrophysics Data System (ADS)

    de Patoul, J.

    2012-04-01

    from simultaneous data observed by two or more spacecrafts. For tomography, we consider the filtered back projection method for which we incorporate the differential rotation of the Sun. For stereoscopy, we use three view directions for a conventional stereoscopic triangulation. These multi-scale Hough-wavelet analyses, stereoscopy and tomography extensions have been applied for the first time in a coronal plumes study. The temporal evolution of the mean orientation of plumes from May 2007 to April 2008 is then analyzed and discussed. Since the plume orientation is assumed to follow the coronal magnetic field, this analysis reveals: (i) a mean orientation of plumes more horizontal than for a dipole magnetic field, (ii) an asymmetry of the coronal open polar cap magnetic field from the solar rotation axis by up to 6° and (iii) a variation of these orientation and asymmetry over the year. Finally, with the help of the reconstructed 3-D geometry of the plumes, we study in detail their temporal evolution as well as the shape and size of their cross sections. The study reveals: (i) different lifetimes of plumes from 2-3 days up to 9 days and (ii) the presence of both near-circular plume cross sections and plumes with curtain-like structures. Also discussed is the plumes positions and their relation to other coronal phenomena such as coronal holes and jets. Plumes are found to be located inside coronal holes, and jets could explain the intensity enhancement within the plumes.

  17. Practical Bayesian tomography

    NASA Astrophysics Data System (ADS)

    Granade, Christopher; Combes, Joshua; Cory, D. G.

    2016-03-01

    In recent years, Bayesian methods have been proposed as a solution to a wide range of issues in quantum state and process tomography. State-of-the-art Bayesian tomography solutions suffer from three problems: numerical intractability, a lack of informative prior distributions, and an inability to track time-dependent processes. Here, we address all three problems. First, we use modern statistical methods, as pioneered by Huszár and Houlsby (2012 Phys. Rev. A 85 052120) and by Ferrie (2014 New J. Phys. 16 093035), to make Bayesian tomography numerically tractable. Our approach allows for practical computation of Bayesian point and region estimators for quantum states and channels. Second, we propose the first priors on quantum states and channels that allow for including useful experimental insight. Finally, we develop a method that allows tracking of time-dependent states and estimates the drift and diffusion processes affecting a state. We provide source code and animated visual examples for our methods.

  18. Efficient quantum state tomography.

    PubMed

    Cramer, Marcus; Plenio, Martin B; Flammia, Steven T; Somma, Rolando; Gross, David; Bartlett, Stephen D; Landon-Cardinal, Olivier; Poulin, David; Liu, Yi-Kai

    2010-01-01

    Quantum state tomography--deducing quantum states from measured data--is the gold standard for verification and benchmarking of quantum devices. It has been realized in systems with few components, but for larger systems it becomes unfeasible because the number of measurements and the amount of computation required to process them grows exponentially in the system size. Here, we present two tomography schemes that scale much more favourably than direct tomography with system size. One of them requires unitary operations on a constant number of subsystems, whereas the other requires only local measurements together with more elaborate post-processing. Both rely only on a linear number of experimental operations and post-processing that is polynomial in the system size. These schemes can be applied to a wide range of quantum states, in particular those that are well approximated by matrix product states. The accuracy of the reconstructed states can be rigorously certified without any a priori assumptions.

  19. 4D Electron Tomography

    NASA Astrophysics Data System (ADS)

    Kwon, Oh-Hoon; Zewail, Ahmed H.

    2010-06-01

    Electron tomography provides three-dimensional (3D) imaging of noncrystalline and crystalline equilibrium structures, as well as elemental volume composition, of materials and biological specimens, including those of viruses and cells. We report the development of 4D electron tomography by integrating the fourth dimension (time resolution) with the 3D spatial resolution obtained from a complete tilt series of 2D projections of an object. The different time frames of tomograms constitute a movie of the object in motion, thus enabling studies of nonequilibrium structures and transient processes. The method was demonstrated using carbon nanotubes of a bracelet-like ring structure for which 4D tomograms display different modes of motion, such as breathing and wiggling, with resonance frequencies up to 30 megahertz. Applications can now make use of the full space-time range with the nanometer-femtosecond resolution of ultrafast electron tomography.

  20. Electron tomography of cells.

    PubMed

    Gan, Lu; Jensen, Grant J

    2012-02-01

    The electron microscope has contributed deep insights into biological structure since its invention nearly 80 years ago. Advances in instrumentation and methodology in recent decades have now enabled electron tomography to become the highest resolution three-dimensional (3D) imaging technique available for unique objects such as cells. Cells can be imaged either plastic-embedded or frozen-hydrated. Then the series of projection images are aligned and back-projected to generate a 3D reconstruction or 'tomogram'. Here, we review how electron tomography has begun to reveal the molecular organization of cells and how the existing and upcoming technologies promise even greater insights into structural cell biology. PMID:22082691

  1. Atom Probe Tomography 2012

    NASA Astrophysics Data System (ADS)

    Kelly, Thomas F.; Larson, David J.

    2012-08-01

    In the world of tomographic imaging, atom probe tomography (APT) occupies the high-spatial-resolution end of the spectrum. It is highly complementary to electron tomography and is applicable to a wide range of materials. The current state of APT is reviewed. Emphasis is placed on applications and data analysis as they apply to many fields of research and development including metals, semiconductors, ceramics, and organic materials. We also provide a brief review of the history and the instrumentation associated with APT and an assessment of the existing challenges in the field.

  2. Attack of the S. Mutans!: a stereoscopic-3D multiplayer direct-manipulation behavior-modification serious game for improving oral health in pre-teens

    NASA Astrophysics Data System (ADS)

    Hollander, Ari; Rose, Howard; Kollin, Joel; Moss, William

    2011-03-01

    Attack! of the S. Mutans is a multi-player game designed to harness the immersion and appeal possible with wide-fieldof- view stereoscopic 3D to combat the tooth decay epidemic. Tooth decay is one of the leading causes of school absences and costs more than $100B annually in the U.S. In 2008 the authors received a grant from the National Institutes of Health to build a science museum exhibit that included a suite of serious games involving the behaviors and bacteria that cause cavities. The centerpiece is an adventure game where five simultaneous players use modified Wii controllers to battle biofilms and bacteria while immersed in environments generated within a 11-foot stereoscopic WUXGA display. The authors describe the system and interface used in this prototype application and some of the ways they attempted to use the power of immersion and the appeal of S3D revolution to change health attitudes and self-care habits.

  3. Distance Perception of Stereoscopically Presented Virtual Objects Optically Superimposed on Physical Objects by a Head-Mounted See-Through Display

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Bucher, Urs J.; Statler, Irving C. (Technical Monitor)

    1994-01-01

    The influence of physically presented background stimuli on the perceived depth of optically overlaid, stereoscopic virtual images has been studied using headmounted stereoscopic, virtual image displays. These displays allow presentation of physically unrealizable stimulus combinations. Positioning of an opaque physical object either at the initial perceived depth of the virtual image or at a position substantially in front of the virtual image, causes the virtual image to perceptually move closer to the observer. In the case of objects positioned substantially in front of the virtual image, subjects often perceive the opaque object to become transparent. Evidence is presented that the apparent change of position caused by interposition of the physical object is not due to occlusion cues. According, it may have an alternative cause such as variation in the binocular vengeance position of the eyes caused by introduction of the physical object. This effect may complicate design of overlaid virtual image displays for near objects and appears to be related to the relative conspicuousness of the overlaid virtual image and the background. Consequently, it may be related to earlier analyses of John Foley which modeled open-loop pointing errors to stereoscopically presented points of light in terms of errors in determination of a reference point for interpretation of observed retinal disparities. Implications for the design of see-through displays for manufacturing will be discussed.

  4. Relationship between Stereoscopic Vision, Visual Perception, and Microstructure Changes of Corpus Callosum and Occipital White Matter in the 4-Year-Old Very Low Birth Weight Children

    PubMed Central

    Kwinta, Przemko; Herman-Sucharska, Izabela; Leśniak, Anna; Klimek, Małgorzata; Karcz, Paulina; Durlak, Wojciech; Nitecka, Magdalena; Dutkowska, Grażyna; Kubatko-Zielińska, Anna; Romanowska-Dixon, Bożena; Pietrzyk, Jacek Józef

    2015-01-01

    Aim. To assess the relationship between stereoscopic vision, visual perception, and microstructure of the corpus callosum (CC) and occipital white matter, 61 children born with a mean birth weight of 1024 g (SD 270 g) were subjected to detailed ophthalmologic evaluation, Developmental Test of Visual Perception (DTVP-3), and diffusion tensor imaging (DTI) at the age of 4. Results. Abnormal stereoscopic vision was detected in 16 children. Children with abnormal stereoscopic vision had smaller CC (CC length: 53 ± 6 mm versus 61 ± 4 mm; p < 0.01; estimated CC area: 314 ± 106 mm2 versus 446 ± 79 mm2; p < 0.01) and lower fractional anisotropy (FA) values in CC (FA value of rostrum/genu: 0.7 ± 0.09 versus 0.79 ± 0.07; p < 0.01; FA value of CC body: 0.74 ± 0.13 versus 0.82 ± 0.09; p = 0.03). We found a significant correlation between DTVP-3 scores, CC size, and FA values in rostrum and body. This correlation was unrelated to retinopathy of prematurity. Conclusions. Visual perceptive dysfunction in ex-preterm children without major sequelae of prematurity depends on more subtle changes in the brain microstructure, including CC. Role of interhemispheric connections in visual perception might be more complex than previously anticipated. PMID:26451381

  5. Holography and tomography

    SciTech Connect

    Howells, M.

    1997-02-01

    This session includes a collection of outlines of pertinent information, diagrams, graphs, electron micrographs, and color photographs pertaining to historical aspects and recent advances in the development of X-ray Gabor Holography. Many of the photographs feature or pertain to instrumentation used in holography, tomography, and cryo-holography.

  6. Waste inspection tomography (WIT)

    SciTech Connect

    Bernardi, R.T.

    1996-12-31

    WIT is a self-sufficient mobile semitrailer for nondestructive evaluation and nondestructive assay of nuclear waste drums using x-ray and gamma-ray tomography. The recently completed Phase I included the design, fabrication, and initial testing of all WIT subsystems installed on-board the trailer. Initial test results include 2 MeV digital radiography, computed tomography, Anger camera imaging, single photon emission computed tomography, gamma-ray spectroscopy, collimated gamma scanning, and active and passive computed tomography using a 1.4 mCi source of {sup 166}Ho. These techniques were initially demonstrated on a 55-gallon phantom drum with 3 simulated waste matrices of combustibles, heterogeneous metals, and cement using check sources of gamma active isotopes such as {sup 137}Cs and {sup 133}Ba with 9-250 {mu}Ci activities. Waste matrix identification, isotopic identification, and attenuation-corrected gamma activity determination were demonstrated nondestructively and noninvasively in Phase I. Currently ongoing Phase II involves DOE site field test demonstrations at LLNL, RFETS, and INEL with real nuclear waste drums. Current WIT experience includes 55 gallon drums of cement, graphite, sludge, glass, metals, and combustibles. Thus far WIT has inspected drums with 0-20 gms of {sup 239}Pu.

  7. Dental Optical Coherence Tomography

    PubMed Central

    Hsieh, Yao-Sheng; Ho, Yi-Ching; Lee, Shyh-Yuan; Chuang, Ching-Cheng; Tsai, Jui-che; Lin, Kun-Feng; Sun, Chia-Wei

    2013-01-01

    This review paper describes the applications of dental optical coherence tomography (OCT) in oral tissue images, caries, periodontal disease and oral cancer. The background of OCT, including basic theory, system setup, light sources, spatial resolution and system limitations, is provided. The comparisons between OCT and other clinical oral diagnostic methods are also discussed. PMID:23857261

  8. Neural networks for calibration tomography

    NASA Technical Reports Server (NTRS)

    Decker, Arthur

    1993-01-01

    Artificial neural networks are suitable for performing pattern-to-pattern calibrations. These calibrations are potentially useful for facilities operations in aeronautics, the control of optical alignment, and the like. Computed tomography is compared with neural net calibration tomography for estimating density from its x-ray transform. X-ray transforms are measured, for example, in diffuse-illumination, holographic interferometry of fluids. Computed tomography and neural net calibration tomography are shown to have comparable performance for a 10 degree viewing cone and 29 interferograms within that cone. The system of tomography discussed is proposed as a relevant test of neural networks and other parallel processors intended for using flow visualization data.

  9. The meaning of interior tomography.

    PubMed

    Wang, Ge; Yu, Hengyong

    2013-08-21

    The classic imaging geometry for computed tomography is for the collection of un-truncated projections and the reconstruction of a global image, with the Fourier transform as the theoretical foundation that is intrinsically non-local. Recently, interior tomography research has led to theoretically exact relationships between localities in the projection and image spaces and practically promising reconstruction algorithms. Initially, interior tomography was developed for x-ray computed tomography. Then, it was elevated to have the status of a general imaging principle. Finally, a novel framework known as 'omni-tomography' is being developed for a grand fusion of multiple imaging modalities, allowing tomographic synchrony of diversified features.

  10. Dual Islet Transplantation Modeling of the Instant Blood-Mediated Inflammatory Reaction

    PubMed Central

    Martin, BM; Samy, KP; Lowe, MC; Thompson, PW; Cano, J; Farris, AB; Song, M; Dove, CR; Leopardi, FV; Strobert, EA; Jenkins, JB; Collins, BH; Larsen, CP; Kirk, AD

    2015-01-01

    Islet xenotransplantation is a potential treatment for diabetes without the limitations of tissue availability. Although successful experimentally, early islet loss remains substantial and attributed to an instant blood mediated inflammatory reaction (IBMIR). This syndrome of islet destruction has been incompletely defined and characterization in pig-to-primate models has been hampered by logistical and statistical limitations of large animal studies. To further investigate IBMIR, we developed a novel in vivo dual islet transplant model to precisely characterize IBMIR as proof-of-concept that this model can serve to properly control experiments comparing modified xenoislet preparations. Wild-type (WT) and α1,3-galactosyltransferase knockout (GTKO) neonatal porcine islets (NPIs) were studied in non-immunosuppressed rhesus macaques. Inert polyethylene microspheres served as a control for the effects of portal embolization. Digital analysis of immunohistochemistry targeting IBMIR mediators was performed at one and 24 hours after intraportal islet infusion. Early findings observed in transplanted islets include complement and antibody deposition, and infiltration by neutrophils, macrophages, and platelets. Insulin, complement, antibody, neutrophils, macrophages, and platelets were similar between GTKO and WT islets, with increasing macrophage infiltration at 24 hours in both phenotypes. This model provides an objective and internally controlled study of distinct islet preparations and documents the temporal histology of IBMIR. PMID:25702898

  11. Time-instant sampling based encoding of time-varying acoustic spectrum

    NASA Astrophysics Data System (ADS)

    Sharma, Neeraj Kumar

    2015-12-01

    The inner ear has been shown to characterize an acoustic stimuli by transducing fluid motion in the inner ear to mechanical bending of stereocilia on the inner hair cells (IHCs). The excitation motion/energy transferred to an IHC is dependent on the frequency spectrum of the acoustic stimuli, and the spatial location of the IHC along the length of the basilar membrane (BM). Subsequently, the afferent auditory nerve fiber (ANF) bundle samples the encoded waveform in the IHCs by synapsing with them. In this work we focus on sampling of information by afferent ANFs from the IHCs, and show computationally that sampling at specific time instants is sufficient for decoding of time-varying acoustic spectrum embedded in the acoustic stimuli. The approach is based on sampling the signal at its zero-crossings and higher-order derivative zero-crossings. We show results of the approach on time-varying acoustic spectrum estimation from cricket call signal recording. The framework gives a time-domain and non-spatial processing perspective to auditory signal processing. The approach works on the full band signal, and is devoid of modeling any bandpass filtering mimicking the BM action. Instead, we motivate the approach from the perspective of event-triggered sampling by afferent ANFs on the stimuli encoded in the IHCs. Though the approach gives acoustic spectrum estimation but it is shallow on its complete understanding for plausible bio-mechanical replication with current mammalian auditory mechanics insights.

  12. Influence of molecular weight on in vitro immunostimulatory properties of instant coffee.

    PubMed

    Passos, Cláudia P; Cepeda, Márcio R; Ferreira, Sónia S; Nunes, Fernando M; Evtuguin, Dmitry V; Madureira, Pedro; Vilanova, Manuel; Coimbra, Manuel A

    2014-10-15

    Instant coffee was prepared and fractionated into higher (>100kDa), medium (5-10, 10-30, 30-100kDa) and lower (1-5, <1kDa) molecular weight fractions. Sugars and linkage composition characteristics of arabinogalactans and galactomannans were recovered in all fractions. Also, amino acid analysis performed after hydrolysis showed similar compositions in all fractions. On the contrary, free chlorogenic acids and caffeine were only detected in the lowest molecular weight fraction (<1kDa). A direct relationship between the melanoidins browning index and the molecular weight was observed. The fractions obtained were incubated in vitro with murine spleen lymphocytes in order to evaluate their possible immunostimulatory abilities. The surface expression of CD69 (early activation marker) on different lymphocyte sub-populations showed that the fraction with 1-5kDa was able to induce activation of B-lymphocytes. This was the only fraction to induce B-lymphocyte activation, since all the other fractions failed, even when higher concentrations were used.

  13. Effect of slice thickness and blanching time on different quality attributes of instant ginger candy.

    PubMed

    Nath, A; Deka, Bidyut C; Jha, A K; Paul, D; Misra, L K

    2013-02-01

    Fresh ginger (Zingiber officinale Rosc.) suffers from weight loss, shrinkage, sprouting and rotting during storage after 3-4 weeks. This spoilage may be overcome by processing fresh produce to some value added products. An attempt was made to optimize the protocol for production of instant ginger candy. The experimental parameters considered were slice thickness (5.0-25.0 mm) and blanching duration (10-30 min) followed by dipping in 40°B and 75°B sugar solutions containing 2.0% citric acid respectively, for 1 and 2 h at 95 °C and dried at 60 °C for 1 h. RSM design was considered for this experiment and final products were evaluated for their textural properties, TSS, acidity, TSS: acid ratio, taste score and overall acceptability. The optimum product qualities in terms of hardness (2.08 kg), TSS (73.4%), acidity (1.31%), TSS: acid ratio (56.3), taste score (7.98) and overall acceptability (8.07) were obtained for slice thickness of 10.9 mm and blanching time of 24.9 min.

  14. Near-instant automatic access to visually presented words in the human neocortex: neuromagnetic evidence

    PubMed Central

    Shtyrov, Yury; MacGregor, Lucy J.

    2016-01-01

    Rapid and efficient processing of external information by the brain is vital to survival in a highly dynamic environment. The key channel humans use to exchange information is language, but the neural underpinnings of its processing are still not fully understood. We investigated the spatio-temporal dynamics of neural access to word representations in the brain by scrutinising the brain’s activity elicited in response to psycholinguistically, visually and phonologically matched groups of familiar words and meaningless pseudowords. Stimuli were briefly presented on the visual-field periphery to experimental participants whose attention was occupied with a non-linguistic visual feature-detection task. The neural activation elicited by these unattended orthographic stimuli was recorded using multi-channel whole-head magnetoencephalography, and the timecourse of lexically-specific neuromagnetic responses was assessed in sensor space as well as at the level of cortical sources, estimated using individual MR-based distributed source reconstruction. Our results demonstrate a neocortical signature of automatic near-instant access to word representations in the brain: activity in the perisylvian language network characterised by specific activation enhancement for familiar words, starting as early as ~70 ms after the onset of unattended word stimuli and underpinned by temporal and inferior-frontal cortices. PMID:27217080

  15. Development of an enzymatic fish hydrolysate and its use in instant soup bases.

    PubMed

    Gálvez, A; Morales de Léon, J; Bourges Rodríguez, H

    1985-12-01

    The successful conservation of fish products, at low costs, is a subject of special interest in the developing countries. Conscious of this fact, our group has been studying several fish conservation methods, such as autolysis with high salt concentrations, and has obtained a sauce of high nutritive value and long shelf life. Nevertheless, the reaction process takes from four to six months. In the study herein reported, the hydrolysis was accelerated and controlled by using the following enzymes: papain, HT proteolytic, and Brew (N) zyme. The hydrolysate was then mixed with cereals to prepare instant soups. As results indicated, the best hydrolysate was obtained with Brew (N) zyme at 50 degrees C and 8.30 hours. This hydrolysate contains 93.0 g/100 g crude protein with a protein efficiency ratio (PER) and a net protein utilization (NPU) of 60% that of casein's NPU as well as a content of 0.8% ether extract. The lowest-cost mixtures with the highest nutritive value were: hydrolysate-wheat-soymeal, and hydrolysate-rice-soymeal, with 38.3 and 29.7 protein per 100 g of mixture, respectively, and a NPU of 79.0 and 79.8% in relation to casein, respectively. The soups prepared had a satisfactory acceptance rating. There were no significant differences in flavor and aroma at a confidence level of 95%. The cost per gram of protein is about US$ 0.22 per kg. PMID:3842931

  16. Performance characterization and transmission schemes for instantly decodable network coding in wireless broadcast

    NASA Astrophysics Data System (ADS)

    Yu, Mingchao; Sadeghi, Parastoo; Aboutorab, Neda

    2015-12-01

    We consider broadcasting a block of packets to multiple wireless receivers under random packet erasures using instantly decodable network coding (IDNC). The sender first broadcasts each packet uncoded once, then generates coded packets according to receivers' feedback about their missing packets. We focus on strict IDNC (S-IDNC), where each coded packet includes at most one missing packet of every receiver. But, we will also study its relation with generalized IDNC (G-IDNC), where this condition is relaxed. We characterize two fundamental performance limits of S-IDNC: (1) the number of transmissions to complete the broadcast, which measures throughput and (2) average packet decoding delay, which measures how fast each packet is decoded at each receiver on average. We derive a closed-form expression for the expected minimum number of transmissions in terms of the number of packets and receivers and the erasure probability. We prove that it is NP-hard to minimize the average packet decoding delay of S-IDNC. We also prove that the graph models of S- and G-IDNC share the same chromatic number. Next, we design efficient S-IDNC transmission schemes and coding algorithms with full/intermittent receiver feedback. We present simulation results to corroborate the developed theory and compare our schemes with existing ones.

  17. Evaluation of instant cup noodle, irradiated for immuno-compromised patients

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hye; Kim, Jae-Kyung; Park, Jae-Nam; Yoon, Young-Min; Sung, Nak-Yun; Kim, Jae-Hun; Song, Beom-Seok; Yook, Hong-Sun; Kim, Byeong-Keun; Lee, Ju-Woon

    2012-08-01

    In the present study, initial microbial load of instant cup noodle (ICN) was investigated and gamma irradiation applied to develop immuno-compromised patients food for their safe consumption. The initial microbial population of dried vegetable and meat, and noodle was below the detection limit (1 log CFU/g); however, that of seasoning powder was just above 4 log CFU/g. Moreover, rehydrated-ICN with water at 100 °C still show above 3 log CFU/g of microbial load, which indicates the need for an additional process to control microbial safety of the seasoning powder. The total aerobic bacteria in seasoning powder and rehydrated-ICN could be controlled with 17 kGy gamma irradiation. This result referred 17 kGy gamma irradiation could reach 'practical sterility' of ICN. The overall difference in sensory properties between the non-irradiated and irradiated ICN was insignificant. Thus, gamma irradiation could improve the microbial quality of ICN, and reduce the risk of infection posed by the seasoning powder, without any adverse effects on their sensory quality. These results suggest that gamma-irradiated ICN can be used as a snack food for immuno-compromised patients.

  18. Reduction of illness absenteeism in elementary schools using an alcohol-free instant hand sanitizer.

    PubMed

    White, C G; Shinder, F S; Shinder, A L; Dyer, D L

    2001-10-01

    Hand washing is the most effective way to prevent the spread of communicable disease. The purpose of this double-blind, placebo-controlled study was to assess whether an alcohol-free, instant hand sanitizer containing surfactants, allantoin, and benzalkonium chloride could reduce illness absenteeism in a population of 769 elementary school children and serve as an effective alternative when regular soap and water hand washing was not readily available. Prior to the study, students were educated about proper hand washing technique, the importance of hand washing to prevent transmission of germs, and the relationship between germs and illnesses. Children in kindergarten through the 6th grade (ages 5-12) were assigned to the active or placebo hand-sanitizer product and instructed to use the product at scheduled times during the day and as needed after coughing or sneezing. Data on illness absenteeism were tracked. After 5 weeks, students using the active product were 33% less likely to have been absent because of illness when compared with the placebo group. PMID:11885342

  19. Instantly AgNPs deposition through facile solventless technique for poly-functional cotton fabrics.

    PubMed

    Emam, Hossam E; Saleh, N H; Nagy, Khaled S; Zahran, M K

    2016-03-01

    Nowadays, functional clothes are employed for human body protection in addition to be fashionable clothes. Hence functionalization of clothes increases the attention of scientists and business. In the current study, poly-functional cotton fabric was carried out by instantly deposition of AgNPs using two solventless techniques namely; sorption and padding. Sorption technique was exhibited extremely high efficiency than padding one by ca. 10 times. By using the same concentrations of AgNO3, Ag content was ranged 69.3-6094.8 mg/kg and 33.8-609.3 mg/kg for sorption and padding, respectively. After AgNPs deposition, fabrics color was turned to gray-reddish yellow. By applying 5912.3 mgAg/kg fabric, bacterial reduction and UPF value were reached 99% and 12.59. Bacterial reduction and UPF were lessened to 90% and 10.19 after 20 washings. These findings proved that the direct AgNPs deposition into cotton using solventless/sorption technique is applicable in manufacturing of antibacterial/UV resistant fabrics with acquired decorative color. PMID:26708429

  20. Road Accident Prevention with Instant Emergency Warning Message Dissemination in Vehicular Ad-Hoc Network.

    PubMed

    Gokulakrishnan, P; Ganeshkumar, P

    2015-01-01

    A Road Accident Prevention (RAP) scheme based on Vehicular Backbone Network (VBN) structure is proposed in this paper for Vehicular Ad-hoc Network (VANET). The RAP scheme attempts to prevent vehicles from highway road traffic accidents and thereby reduces death and injury rates. Once the possibility of an emergency situation (i.e. an accident) is predicted in advance, instantly RAP initiates a highway road traffic accident prevention scheme. The RAP scheme constitutes the following activities: (i) the Road Side Unit (RSU) constructs a Prediction Report (PR) based on the status of the vehicles and traffic in the highway roads, (ii) the RSU generates an Emergency Warning Message (EWM) based on an abnormal PR, (iii) the RSU forms a VBN structure and (iv) the RSU disseminates the EWM to the vehicles that holds the high Risk Factor (RF) and travels in High Risk Zone (HRZ). These vehicles might reside either within the RSU's coverage area or outside RSU's coverage area (reached using VBN structure). The RAP scheme improves the performance of EWM dissemination in terms of increase in notification and decrease in end-to-end delay. The RAP scheme also reduces infrastructure cost (number of RSUs) by formulating and deploying the VBN structure. The RAP scheme with VBN structure improves notification by 19 percent and end-to-end delay by 14.38 percent for a vehicle density of 160 vehicles. It is also proved from the simulation experiment that the performance of RAP scheme is promising in 4-lane highway roads.

  1. Near-instant automatic access to visually presented words in the human neocortex: neuromagnetic evidence.

    PubMed

    Shtyrov, Yury; MacGregor, Lucy J

    2016-01-01

    Rapid and efficient processing of external information by the brain is vital to survival in a highly dynamic environment. The key channel humans use to exchange information is language, but the neural underpinnings of its processing are still not fully understood. We investigated the spatio-temporal dynamics of neural access to word representations in the brain by scrutinising the brain's activity elicited in response to psycholinguistically, visually and phonologically matched groups of familiar words and meaningless pseudowords. Stimuli were briefly presented on the visual-field periphery to experimental participants whose attention was occupied with a non-linguistic visual feature-detection task. The neural activation elicited by these unattended orthographic stimuli was recorded using multi-channel whole-head magnetoencephalography, and the timecourse of lexically-specific neuromagnetic responses was assessed in sensor space as well as at the level of cortical sources, estimated using individual MR-based distributed source reconstruction. Our results demonstrate a neocortical signature of automatic near-instant access to word representations in the brain: activity in the perisylvian language network characterised by specific activation enhancement for familiar words, starting as early as ~70 ms after the onset of unattended word stimuli and underpinned by temporal and inferior-frontal cortices. PMID:27217080

  2. Conducting instant adhesives by grafting of silane polymer onto expanded graphite.

    PubMed

    Mondal, Titash; Bhowmick, Anil K; Krishnamoorti, Ramanan

    2014-09-24

    A "grafting to" methodology for the attachment of a silane based polymer (SG) onto functionalized graphitic platelets is demonstrated. The siloxy end groups of the modifier were further cross-linked without addition of any external curative. These sterically stabilized nanoplatelets with a high grafting density ensured complete screening of the attractive interparticle interactions. As a result, a better dispersion of platelets was observed compared to the physically mixed platelets in the polymer matrix (SUG). The larger size of the polymer tethered graphitic particles and the greater extent of heat liberated due to grafting resulted in a higher enthalpic contribution in the case of SG compared to SUG. This makes the formation of SG thermodynamically more favorable compared to SUG. Presence of a hierarchical spatial arrangement with a good dispersion of graphitic platelets was observed within the siloxane matrix in the case of SG compared to SUG. The nanoparticle tethered composite generated exhibited an "instant" conducting adhesive behavior. The adhesive properties of the SG were found to be increased due to grafting of graphitic platelets when compared with the neat polymer. Further, SG exhibited a conductive character whereas the neat polymer and SUG demonstrated an insulating character.

  3. Instant Blood-Mediated Inflammatory Reaction in Hepatocyte Transplantation: Current Status and Future Perspectives.

    PubMed

    Lee, Charlotte A; Dhawan, Anil; Smith, Richard A; Mitry, Ragai R; Fitzpatrick, Emer

    2016-01-01

    Hepatocyte transplantation (HT) is emerging as a promising alternative to orthotopic liver transplantation (OLT) in patients with certain liver-based metabolic disease and acute liver failure. Hepatocytes are generally infused into the portal venous system, from which they migrate into the liver cell plates of the native organ. One of the major hurdles to the sustained success of this therapy is early cell loss, with up to 70% of hepatocytes lost immediately following infusion. This is largely thought to be due to the instant blood-mediated inflammatory reaction (IBMIR), resulting in the activation of complement and coagulation pathways. Transplanted hepatocytes produce and release tissue factor (TF), which activates the coagulation pathway, leading to the formation of thrombin and fibrin clots. Thrombin can further activate a number of complement proteins, leading to the activation of the membrane attack complex (MAC) and subsequent hepatocyte cell death. Inflammatory cells including granulocytes, monocytes, Kupffer cells, and natural killer (NK) cells have been shown to cluster around transplanted hepatocytes, leading to their rapid clearance shortly after transplantation. Current research aims to improve cell engraftment and prevent early cell loss. This has been proven successful in vitro using pharmacological interventions such as melagatran, low-molecular-weight dextran sulphate, and N-acetylcysteine (NAC). Effective inhibition of IBMIR would significantly improve hepatocyte engraftment, proliferation, and function, providing successful treatment for patients with liver-based metabolic diseases. PMID:26996786

  4. Ultrasound contrast agent fabricated from microbubbles containing instant adhesives, and its ultrasound imaging ability

    NASA Astrophysics Data System (ADS)

    Makuta, T.; Tamakawa, Y.

    2012-04-01

    Non-invasive surgery techniques and drug delivery system with acoustic characteristics of ultrasound contrast agent have been studied intensively in recent years. Ultrasound contrast agent collapses easily under the blood circulating and the ultrasound irradiating because it is just a stabilized bubble without solid-shell by surface adsorption of surfactant or lipid. For improving the imaging stability, we proposed the fabrication method of the hollow microcapsule with polymer shell, which can be fabricated just blowing vapor of commonly-used instant adhesive (Cyanoacrylate monomer) into water as microbubbles. Therefore, the cyanoacrylate vapor contained inside microbubble initiates polymerization on the gasliquid interface soon after microbubbles are generated in water. Consequently, hollow microspheres coated by cyanoacrylate thin film are generated. In this report, we revealed that diameter distributions of microbubbles and microcapsules were approximately same and most of them were less than 10 μm, that is, smaller than blood capillary. In addition, we also revealed that hollow microcapsules enhanced the acoustic signal especially in the harmonic contrast imaging and were broken or agglomerated under the ultrasound field. As for the yield of hollow microcapsules, we revealed that sodium dodecyl sulfate addition to water phase instead of deoxycolic acid made the fabrication yield increased.

  5. Instant messaging addiction among teenagers in China: shyness, alienation, and academic performance decrement.

    PubMed

    Huang, Hanyun; Leung, Louis

    2009-12-01

    This exploratory research proposes the concept of instant messaging (IM) addiction and examines (a) whether IM addiction exists among Chinese teenagers and, if so, who the addicts are, what their symptoms are, and to what extent they are addicted; (b) whether psychological variables such as shyness and alienation can predict IM use or addiction among teenagers; and (c) whether IM use or IM addiction can impair the academic performance of teenagers. Using Young's classic definition of Internet addiction, results of a stratified random sample of 330 teenagers in China in 2007 found 95.8% of participants use IM, and 9.8% of them can be classified as IM addicts. Factor analysis identified four major IM addiction symptoms among teenagers: preoccupation with IM, loss of relationships due to overuse, loss of control, and escape. Results also showed that shyness and alienation from family, peers, and school are significantly and positively associated with levels of IM addiction. As expected, both the level of IM use and level of IM addiction are significantly linked to teenagers' academic performance decrement. PMID:19788380

  6. JiffyNet: a web-based instant protein network modeler for newly sequenced species.

    PubMed

    Kim, Eiru; Kim, Hanhae; Lee, Insuk

    2013-07-01

    Revolutionary DNA sequencing technology has enabled affordable genome sequencing for numerous species. Thousands of species already have completely decoded genomes, and tens of thousands more are in progress. Naturally, parallel expansion of the functional parts list library is anticipated, yet genome-level understanding of function also requires maps of functional relationships, such as functional protein networks. Such networks have been constructed for many sequenced species including common model organisms. Nevertheless, the majority of species with sequenced genomes still have no protein network models available. Moreover, biologists might want to obtain protein networks for their species of interest on completion of the genome projects. Therefore, there is high demand for accessible means to automatically construct genome-scale protein networks based on sequence information from genome projects only. Here, we present a public web server, JiffyNet, specifically designed to instantly construct genome-scale protein networks based on associalogs (functional associations transferred from a template network by orthology) for a query species with only protein sequences provided. Assessment of the networks by JiffyNet demonstrated generally high predictive ability for pathway annotations. Furthermore, JiffyNet provides network visualization and analysis pages for wide variety of molecular concepts to facilitate network-guided hypothesis generation. JiffyNet is freely accessible at http://www.jiffynet.org.

  7. The Simultineous Enzymatic Hydrolysis of Tapioca Starch for Instant Formation of Glucose

    NASA Astrophysics Data System (ADS)

    Sarbatly, Rosalam

    This study investigated the possibility of simultaneous reactions of the gelatinization, liquefaction and saccharification (SGLS) carried out at two reaction temperatures of saccharification 55 and 60°C for instant glucose production as well as controlling low viscosity of solute over the hydrolysis period. At 55°C, 10% (w/w) of the tapioca starch and 0.9 mL L-1 of a blending mixture of α-amylase and amyloglocosidase, the viscosity was kept low below 2.2x10-3 pa-s throughout the hydrolysis process. The conversion of the tapioca starch to glucose was as high as 65% (w/w) over 28 h of the hydrolysis time. Increasing the temperature to 60°C did not increase the conversion but, (1) increased the maximum rate of reaction from 8.89g L-1 h-1 to 13.3 g L-1h-1 (2) reduced the time to reach a half of the final glucose concentration from 6.1 to 5 h and also (3) slightly increased the earlier stage of solute viscosity without affecting the entire process.

  8. Acrylamide, 5-hydroxymethylfurfural and N(ε)-carboxymethyl-lysine in coffee substitutes and instant coffees.

    PubMed

    Loaëc, Grégory; Jacolot, Philippe; Helou, Cynthia; Niquet-Léridon, Céline; Tessier, Frédéric J

    2014-04-01

    Sensitive analytical methods were developed and validated for the quantification of acrylamide, N(ε)-carboxymethyl-lysine (CML) and 5-hydroxymethylfurfural (HMF) in 24 commercial coffee substitutes (CSs) and 12 instant coffees (ICs). Acrylamide levels varied widely from 200 to 4940 µg kg(-1) with higher levels in CSs. Only two out of 24 CSs had a level of acrylamide above the indicative value set for this food category by the European Commission (4000 µg kg(-1)). None of the ICs tested in this study exceeded the indicative value set for this foodstuff (900 µg kg(-1)). CML ranged from 0.17 to 47 mg kg(-1) and it increased in proportion to the protein content of the samples. The highest concentrations were found in IC partly due to the relatively high protein content of this food group. HMF was the most abundant neoformed compound (NFC) found in the tested commercial samples. It was found between 0.59 and 13 g kg(-1). Among other food categories IC and CS could appear to be major contributors to the exposure to NFCs if consumed on a daily basis. Further investigations are needed to elucidate the acrylamide formation during processing and to determine the daily intake level of frequent consumers of these products.

  9. Instant spectral assignment for advanced decision tree-driven mass spectrometry.

    PubMed

    Bailey, Derek J; Rose, Christopher M; McAlister, Graeme C; Brumbaugh, Justin; Yu, Pengzhi; Wenger, Craig D; Westphall, Michael S; Thomson, James A; Coon, Joshua J

    2012-05-29

    We have developed and implemented a sequence identification algorithm (inSeq) that processes tandem mass spectra in real-time using the mass spectrometer's (MS) onboard processors. The inSeq algorithm relies on accurate mass tandem MS data for swift spectral matching with high accuracy. The instant spectral processing technology takes ∼16 ms to execute and provides information to enable autonomous, real-time decision making by the MS system. Using inSeq and its advanced decision tree logic, we demonstrate (i) real-time prediction of peptide elution windows en masse (∼3 min width, 3,000 targets), (ii) significant improvement of quantitative precision and accuracy (~3x boost in detected protein differences), and (iii) boosted rates of posttranslation modification site localization (90% agreement in real-time vs. offline localization rate and an approximate 25% gain in localized sites). The decision tree logic enabled by inSeq promises to circumvent problems with the conventional data-dependent acquisition paradigm and provides a direct route to streamlined and expedient targeted protein analysis.

  10. EDITORIAL: Industrial Process Tomography

    NASA Astrophysics Data System (ADS)

    West, Robert M.

    2004-07-01

    Industrial process tomography remains a multidisciplinary field with considerable interest for many varied participants. Indeed this adds greatly to its appeal. It is a pleasure and a privilege to once again act as guest editor for a special feature issue of Measurement Science and Technology on industrial process tomography, the last being in December 2002. Those involved in the subject appreciate the efforts of Measurement Science and Technology in producing another issue and I thank the journal on their behalf. It can be seen that there are considerable differences in the composition of material covered in this issue compared with previous publications. The dominance of electrical impedance and electrical capacitance techniques is reduced and there is increased emphasis on general utility of tomographic methods. This is encompassed in the papers of Hoyle and Jia (visualization) and Dierick et al (Octopus). Electrical capacitance tomography has been a core modality for industrial applications. This issue includes new work in two very interesting aspects of image reconstruction: pattern matching (Takei and Saito) and simulated annealing (Ortiz-Aleman et al). It is important to take advantage of knowledge of the process such as the presence of only two components, and then to have robust reconstruction methods provided by pattern matching and by simulated annealing. Although crude reconstruction methods such as approximation by linear back projection were utilized for initial work on electrical impedance tomography, the techniques published here are much more advanced. The paper by Kim et al includes modelling of a two-component system permitting an adaption-related approach; the paper by Tossavainen et al models free surface boundaries to enable the estimation of shapes of objects within the target. There are clear improvements on the previous crude and blurred reconstructions where boundaries were merely inferred rather than estimated as in these new developments

  11. Console-integrated stereoscopic OsiriX 3D volume-rendered images for da Vinci colorectal robotic surgery.

    PubMed

    Volonté, Francesco; Pugin, Francois; Buchs, Nicolas Christian; Spaltenstein, Joël; Hagen, Monika; Ratib, Osman; Morel, Philippe

    2013-04-01

    The increased distance between surgeon and surgical field is a significant problem in laparoscopic surgery. Robotic surgery, although providing advantages for the operator, increases this gap by completely removing force feedback. Enhancement with visual tools can therefore be beneficial. The goal of this preliminary work was to create a custom plugin for OsiriX to display volume-rendered images in the da Vinci surgeon's console. The TilePro multi-input display made the generated stereoscopic pairs appear to have depth. Tumor position, vascular supply, spatial location, and relationship between organs appear directly within the surgeon's field of view. This study presents a case of totally robotic right colectomy for cancer using this new technology. Sight diversion was no longer necessary. Depth perception was subjectively perceived as profitable. Total immersion in the operative field helped compensate for the lack of tactile feedback specific to robotic intervention. This innovative tool is a step forward toward augmented-reality robot-assisted surgery. PMID:22549904

  12. Effect of short-term exposure to stereoscopic three-dimensional flight displays on real-world depth perception

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

    1991-01-01

    High-fidelity color pictorial displays that incorporate depth cues in the display elements are currently available. Depth cuing applied to advanced head-down flight display concepts potentially enhances the pilot's situational awareness and improves task performance. Depth cues provided by stereopsis exhibit constraints that must be fully understood so depth cuing enhancements can be adequately realized and exploited. A fundamental issue (the goal of this investigation) is whether the use of head-down stereoscopic displays in flight applications degrade the real-world depth perception of pilots using such displays. Stereoacuity tests are used in this study as the measure of interest. Eight pilots flew repeated simulated landing approaches using both nonstereo and stereo 3-D head-down pathway-in-the-sky displays. At this decision height of each approach (where the pilot changes to an out-the-window view to obtain real-world visual references) the pilots changed to a stereoacuity test that used real objects. Statistical analysis of stereoacuity measures (data for a control condition of no exposure to any electronic flight display compared with data for changes from nonstereo and from stereo displays) reveals no significant differences for any of the conditions. Therefore, changing from short-term exposure to a head-down stereo display has no more effect on real-world relative depth perception than does changing from a nonstereo display. However, depth perception effects based on sized and distance judgements and on long-term exposure remain issues to be investigated.

  13. Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras

    NASA Astrophysics Data System (ADS)

    Kataoka, R.; Miyoshi, Y.; Shigematsu, K.; Hampton, D.; Mori, Y.; Kubo, T.; Yamashita, A.; Tanaka, M.; Takahei, T.; Nakai, T.; Miyahara, H.; Shiokawa, K.

    2013-09-01

    A new stereoscopic measurement technique is developed to obtain an all-sky altitude map of aurora using two ground-based digital single-lens reflex (DSLR) cameras. Two identical full-color all-sky cameras were set with an 8 km separation across the Chatanika area in Alaska (Poker Flat Research Range and Aurora Borealis Lodge) to find localized emission height with the maximum correlation of the apparent patterns in the localized pixels applying a method of the geographical coordinate transform. It is found that a typical ray structure of discrete aurora shows the broad altitude distribution above 100 km, while a typical patchy structure of pulsating aurora shows the narrow altitude distribution of less than 100 km. Because of its portability and low cost of the DSLR camera systems, the new technique may open a unique opportunity not only for scientists but also for night-sky photographers to complementarily attend the aurora science to potentially form a dense observation network.

  14. Benchmark three-dimensional eye-tracking dataset for visual saliency prediction on stereoscopic three-dimensional video

    NASA Astrophysics Data System (ADS)

    Banitalebi-Dehkordi, Amin; Nasiopoulos, Eleni; Pourazad, Mahsa T.; Nasiopoulos, Panos

    2016-01-01

    Visual attention models (VAMs) predict the location of image or video regions that are most likely to attract human attention. Although saliency detection is well explored for two-dimensional (2-D) image and video content, there have been only a few attempts made to design three-dimensional (3-D) saliency prediction models. Newly proposed 3-D VAMs have to be validated over large-scale video saliency prediction datasets, which also contain results of eye-tracking information. There are several publicly available eye-tracking datasets for 2-D image and video content. In the case of 3-D, however, there is still a need for large-scale video saliency datasets for the research community for validating different 3-D VAMs. We introduce a large-scale dataset containing eye-tracking data collected from 61 stereoscopic 3-D videos (and also 2-D versions of those), and 24 subjects participated in a free-viewing test. We evaluate the performance of the existing saliency detection methods over the proposed dataset. In addition, we created an online benchmark for validating the performance of the existing 2-D and 3-D VAMs and facilitating the addition of new VAMs to the benchmark. Our benchmark currently contains 50 different VAMs.

  15. Three-dimensional temporally resolved measurements of turbulence-flame interactions using orthogonal-plane cinema-stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Steinberg, Adam Michael; Driscoll, James F.; Ceccio, Steven L.

    2009-09-01

    A new orthogonal-plane cinema-stereoscopic particle image velocimetry (OPCS-PIV) diagnostic has been used to measure the dynamics of three-dimensional turbulence-flame interactions. The diagnostic employed two orthogonal PIV planes, with one aligned perpendicular and one aligned parallel to the streamwise flow direction. In the plane normal to the flow, temporally resolved slices of the nine-component velocity gradient tensor were determined using Taylor’s hypothesis. Volumetric reconstruction of the 3D turbulence was performed using these slices. The PIV plane parallel to the streamwise flow direction was then used to measure the evolution of the turbulence; the path and strength of 3D turbulent structures as they interacted with the flame were determined from their image in this second plane. Structures of both vorticity and strain-rate magnitude were extracted from the flow. The geometry of these structures agreed well with predictions from direct numerical simulations. The interaction of turbulent structures with the flame also was observed. In three dimensions, these interactions had complex geometries that could not be reflected in either planar measurements or simple flame-vortex configurations.

  16. STEREOSCOPIC DETERMINATION OF HEIGHTS OF EXTREME ULTRAVIOLET BRIGHT POINTS USING DATA TAKEN BY SECCHI/EUVI ABOARD STEREO

    SciTech Connect

    Kwon, Ryun-Young; Chae, Jongchul; Zhang Jie

    2010-05-01

    We measure the heights of EUV bright points (BPs) above the solar surface by applying a stereoscopic method to the data taken by the Solar TErrestrial RElations Observatory/SECCHI/Extreme UltraViolet Imager (EUVI). We have developed a three-dimensional reconstruction method for point-like features such as BPs using the simple principle that the position of a point in the three-dimensional space is specified as the intersection of two lines of sight. From a set of data consisting of EUVI 171 A, 195 A, 284 A, and 304 A images taken on 11 days arbitrarily selected during a period of 14 months, we have identified and analyzed 210 individual BPs that were visible on all four passband images and smaller than 30 Mm. The BPs seen in the 304 A images have an average height of 4.4 Mm, and are often associated with the legs of coronal loops. In the 171 A, 195 A, and 284 A images the BPs appear loop-shaped, and have average heights of 5.1, 6.7, and 6.1 Mm, respectively. Moreover, there is a tendency that overlying loops are filled with hotter plasmas. The average heights of BPs in 171 A, 195 A, and 284 A passbands are roughly twice the corresponding average lengths. Our results support the notion that an EUV BP represents a system of small loops with temperature stratification like flaring loops, being consistent with the magnetic reconnection origin.

  17. 3D pressure imaging of an aircraft propeller blade-tip flow by phase-locked stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Ragni, D.; van Oudheusden, B. W.; Scarano, F.

    2012-02-01

    The flow field at the tip region of a scaled DHC Beaver aircraft propeller, running at transonic speed, has been investigated by means of a multi-plane stereoscopic particle image velocimetry setup. Velocity fields, phase-locked with the blade rotational motion, are acquired across several planes perpendicular to the blade axis and merged to form a 3D measurement volume. Transonic conditions have been reached at the tip region, with a revolution frequency of 19,800 rpm and a relative free-stream Mach number of 0.73 at the tip. The pressure field and the surface pressure distribution are inferred from the 3D velocity data through integration of the momentum Navier-Stokes equation in differential form, allowing for the simultaneous flow visualization and the aerodynamic loads computation, with respect to a reference frame moving with the blade. The momentum and pressure data are further integrated by means of a contour-approach to yield the aerodynamic sectional force components as well as the blade torsional moment. A steady Reynolds averaged Navier-Stokes numerical simulation of the entire propeller model has been used for comparison to the measurement data.

  18. Experimental insights into flow impingement in cerebral aneurysm by stereoscopic particle image velocimetry: transition from a laminar regime.

    PubMed

    Yagi, Takanobu; Sato, Ayaka; Shinke, Manabu; Takahashi, Sara; Tobe, Yasutaka; Takao, Hiroyuki; Murayama, Yuichi; Umezu, Mitsuo

    2013-05-01

    This study experimentally investigated the instability of flow impingement in a cerebral aneurysm, which was speculated to promote the degradation of aneurysmal wall. A patient-specific, full-scale and elastic-wall replica of cerebral artery was fabricated from transparent silicone rubber. The geometry of the aneurysm corresponded to that found at 9 days before rupture. The flow in a replica was analysed by quantitative flow visualization (stereoscopic particle image velocimetry) in a three-dimensional, high-resolution and time-resolved manner. The mid-systolic and late-diastolic flows with a Reynolds number of 450 and 230 were compared. The temporal and spatial variations of near-wall velocity at flow impingement delineated its inherent instability at a low Reynolds number. Wall shear stress (WSS) at that site exhibited a combination of temporal fluctuation and spatial divergence. The frequency range of fluctuation was found to exceed significantly that of the heart rate. The high-frequency-fluctuating WSS appeared only during mid-systole and disappeared during late diastole. These results suggested that the flow impingement induced a transition from a laminar regime. This study demonstrated that the hydrodynamic instability of shear layer could not be neglected even at a low Reynolds number. No assumption was found to justify treating the aneurysmal haemodynamics as a fully viscous laminar flow.

  19. Stereoscopic particle image velocimetry measurements of the three-dimensional flow field of a descending autorotating mahogany seed (Swietenia macrophylla).

    PubMed

    Salcedo, E; Treviño, C; Vargas, R O; Martínez-Suástegui, L

    2013-06-01

    An experimental investigation of near field aerodynamics of wind dispersed rotary seeds has been performed using stereoscopic digital particle image velocimetry (DPIV). The detailed three-dimensional flow structure of the leading-edge vortex (LEV) of autorotating mahogany seeds (Swietenia macrophylla) in a low-speed vertical wind tunnel is revealed for the first time. The results confirm that the presence of strong spanwise flow and strain produced by centrifugal forces through a spiral vortex are responsible for the attachment and stability of the LEV, with its core forming a cone pattern with a gradual increase in vortex size. The LEV appears at 25% of the wingspan, increases in size and strength outboard along the wing, and reaches its maximum stability and spanwise velocity at 75% of the wingspan. At a region between 90 and 100% of the wingspan, the strength and stability of the vortex core decreases and the LEV re-orientation/inflection with the tip vortex takes place. In this study, the instantaneous flow structure and the instantaneous velocity and vorticity fields measured in planes parallel to the free stream direction are presented as contour plots using an inertial and a non-inertial frame of reference. Results for the mean aerodynamic thrust coefficients as a function of the Reynolds number are presented to supplement the DPIV data.

  20. Stereoscopic particle image velocimetry measurements of the three-dimensional flow field of a descending autorotating mahogany seed (Swietenia macrophylla).

    PubMed

    Salcedo, E; Treviño, C; Vargas, R O; Martínez-Suástegui, L

    2013-06-01

    An experimental investigation of near field aerodynamics of wind dispersed rotary seeds has been performed using stereoscopic digital particle image velocimetry (DPIV). The detailed three-dimensional flow structure of the leading-edge vortex (LEV) of autorotating mahogany seeds (Swietenia macrophylla) in a low-speed vertical wind tunnel is revealed for the first time. The results confirm that the presence of strong spanwise flow and strain produced by centrifugal forces through a spiral vortex are responsible for the attachment and stability of the LEV, with its core forming a cone pattern with a gradual increase in vortex size. The LEV appears at 25% of the wingspan, increases in size and strength outboard along the wing, and reaches its maximum stability and spanwise velocity at 75% of the wingspan. At a region between 90 and 100% of the wingspan, the strength and stability of the vortex core decreases and the LEV re-orientation/inflection with the tip vortex takes place. In this study, the instantaneous flow structure and the instantaneous velocity and vorticity fields measured in planes parallel to the free stream direction are presented as contour plots using an inertial and a non-inertial frame of reference. Results for the mean aerodynamic thrust coefficients as a function of the Reynolds number are presented to supplement the DPIV data. PMID:23430990