Science.gov

Sample records for instant stereoscopic tomography

  1. Instant Stereoscopic Tomography of Active Regions with STEREO/EUVI

    NASA Astrophysics Data System (ADS)

    Aschwanden, M. J.; Wuelser, J.; Nitta, N.; Lemen, J.; Sandman, A.

    2008-12-01

    We develop a novel 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 ~1 minute with the recent STEREO/EUVI instrument, this method is about 4 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 stereosocpic image pair with an accuracy of a few percent (of the average flux) in each pixel. With the stereoscopic tomography we infer also a differential emission measure (DEM) distribution over the entire temperature range of T~0.01-10 MK, 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 EUV loops with apex temperatures of T = 1- 3 MK tend to be super-hydrostatic, while hotter loops with T = 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. First Three-Dimensional Reconstructions of Coronal Loops with the STEREO A+B Spacecraft. III. Instant Stereoscopic Tomography of Active Regions

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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 ≈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 ≈ 104-107, 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 Tm lsim 3.0 MK tend to be super-hydrostatic, while hotter loops with Tm ≈ 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.

  3. 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.

  4. Stereoscopic vascular models of the head and neck: A computed tomography angiography visualization.

    PubMed

    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 anatomy includes use of computed tomography angiography (CTA) images of the head and neck to create clinically relevant 3D stereoscopic virtual models. These high resolution images of the arteries can be used in unique and innovative ways to create 3D virtual models of the vasculature as a tool for teaching anatomy. Blood vessel 3D models are presented stereoscopically in a virtual reality environment, can be rotated 360° in all axes, and magnified according to need. In addition, flexible views of internal structures are possible. Images are displayed in a stereoscopic mode, and students view images in a small theater-like classroom while wearing polarized 3D glasses. Reconstructed 3D models enable students to visualize vascular structures with clinically relevant anatomical variations in the head and neck and appreciate spatial relationships among the blood vessels, the skull and the skin. PMID:25929248

  5. 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

  6. 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

  7. Novel microscope-integrated stereoscopic display for intrasurgical optical coherence tomography

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    The first generation of intrasurgical optical coherence tomography (OCT) systems displayed OCT data onto a separate computer monitor, requiring surgeons to look away from the surgical microscope. In order to provide real-time OCT feedback without requiring surgeons to look away during surgeries, recent prototype research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into the surgical microscopes to allow the surgeons to access the OCT data and the surgical field through the oculars concurrently. However, all current intrasurgical OCT systems with a HUD are only capable of imaging through one ocular limiting the surgeon's depth perception of OCT volumes. Stereoscopy is an effective technology to dramatically increase depth perception by presenting an image from slightly different angles to each eye. Conventional stereoscopic HUD use a pair of micro displays which require bulky optics. Several new approaches for HUDs are reported to use only one micro display at the expense of image brightness or increased footprint. Therefore, these techniques for HUD are not suitable to be integrated into microscopes. We have developed a novel stereoscopic HUD which uses spatial multiplexing to project stereo views into both oculars simultaneously with only one micro-display and three optical elements for our microscope-integrated OCT system. Simultaneous stereoscopic views of OCT volumes are computed in real time by GPU-enabled OCT system software. We present, to our knowledge, the first microscope integrated stereoscopic HUD used for intrasurgical OCT with a novel optical design for stereoscopic viewing devices and report on its preliminary use in human vitreoretinal surgeries.

  8. 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)

  9. 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…

  10. Instant holography

    NASA Astrophysics Data System (ADS)

    Ramanujam, P. S.; Pedersen, M.; Hvilsted, S.

    1999-05-01

    Instant photography, epitomized by Polaroid films is characterized by the rapid appearance of an image after exposure. We describe here an instant off-axis holographic process, characterized by exposures as short as 5 ns and an instant display process, not requiring any wet chemical processing. The holograms are made in a side-chain azobenzene polyester and can be erased through a thermal treatment of the film enabling the film to be reused. Significantly, an atomic force microscopic scan of the film shows a strong surface relief after the 5 ns exposure paving the way for a cheap, mass replication of the holograms using a micromolding technique.

  11. Novel and quick coronary image analysis by instant stent-accentuated three-dimensional optical coherence tomography system in catheterization laboratory.

    PubMed

    Nakao, Fumiaki; Ueda, Tooru; Nishimura, Shigehiko; Uchinoumi, Hitoshi; Kanemoto, Masashi; Tanaka, Nobuaki; Fujii, Takashi

    2013-07-01

    In order to confirm the relation between stent struts and the jailed side branch (SB), the actual wire re-crossing position and the optimal wire re-crossing position during a bifurcation stenting, we developed the instant stent-accentuated three-dimensional optical coherence tomography (iSA 3D-OCT) system based on a novel algorithm. Stent struts in two-dimensional optical coherence tomography (2D-OCT) are represented as high-intensity line segments or spots in low-intensity background. Stent struts disappear and a vessel image is created by the mean filter followed by the minimum filter. A strut image is created by subtracting a vessel image from an original image, and accentuated. By adding a vessel image to a strut image, iSA 2D-OCT is created. It took only 3 s to accentuate stent struts of 100 frames by ImageJ with its macro program. By the iSA 3D-OCT system which consists of the console of OCT, the USB selector, USB cables, the USB flash drive, the computer, and three freeware programs, it took about 65 s from an export of the image data to an observation of iSA 3D-OCT semi-automatically. During a bifurcation stenting procedure, we could confirm the relation between stent struts and the jailed SB, the actual wire re-crossing position and the optimal wire re-crossing position. Using the iSA 3D-OCT system, a detailed process during a bifurcation PCI can be observed in very short waiting time, about 65 s. It is expected to improve the outcome of a complicated bifurcation PCI by the iSA 3D-OCT system. PMID:23355032

  12. 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.

  13. "Diabetes Has Instant Consequences..."

    MedlinePlus

    ... please turn Javascript on. Feature: Diabetes Stories "Diabetes has instant consequences…" Past Issues / Fall 2009 Table of ... you want to chuck it all. But Diabetes has instant consequences. You learn to be responsible pretty ...

  14. 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.

  15. 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

  16. A stereoscopic vision system

    NASA Astrophysics Data System (ADS)

    Kiraly, Zsolt

    In this investigation an optical system is introduced that is suitable 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 transmits wirelessly stereoscopic (three-dimensional) video to a computer which displays the video on the screen where it can be viewed with shutter glasses. To minimize space requirements, the video from the two cameras (required to produce stereoscopic images) is 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 were developed that enable the system to perform these tasks. A proof-of-concept device was constructed that demonstrates the operation and the practicality of the optical system. Using this device, tests were performed validating the concepts and the algorithms.

  17. 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.

  18. Computational stereoscopic zoom

    NASA Astrophysics Data System (ADS)

    Lee, Seungkyu; Lim, Hwasup; Kim, James D. K.; Kim, Chang Yeong

    2012-03-01

    Optical zoom lenses mounted on a stereo color camera magnify each left and right two-dimensional (2-D) image increasing focal length. However, without adjusting the baseline distance, the optical zoom distorts three-dimensional (3-D) perception because the optical zoom magnifies projected 2-D images not an original 3-D object. We propose a computational approach to stereoscopic zoom that magnifies stereo images without 3-D distortion. We computationally manipulate the baseline distance and convergence angle between left and right images by synthesizing novel view stereo images based on the depth information. We suggest a volume-predicted bidirectional occlusion inpainting method for novel view synthesis. Original color image is warped to the novel view determined by the adjusted baseline and convergence angle. Rear volume of each foreground object is predicted, and the foreground portion of each occlusion region is identified. Then we apply our inpainting method to fill in the foreground and background respectively. Experimental results show that the proposed inpainting method removes the cardboard effect that significantly decreases the perceptual quality of synthesized novel view image but has never been addressed in the literature. Finally, 3-D object presented by stereo images is magnified by the proposed stereoscopic zoom method without 3-D distortion.

  19. 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.

  20. 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.

  1. Stereoscopic Configurations To Minimize Distortions

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.

    1991-01-01

    Proposed television system provides two stereoscopic displays. Two-camera, two-monitor system used in various camera configurations and with stereoscopic images on monitors magnified to various degrees. Designed to satisfy observer's need to perceive spatial relationships accurately throughout workspace or to perceive them at high resolution in small region of workspace. Potential applications include industrial, medical, and entertainment imaging and monitoring and control of telemanipulators, telerobots, and remotely piloted vehicles.

  2. [Dendrobium officinale stereoscopic cultivation method].

    PubMed

    Si, Jin-Ping; Dong, Hong-Xiu; Liao, Xin-Yan; Zhu, Yu-Qiu; Li, Hui

    2014-12-01

    The study is aimed to make the most of available space of Dendrobium officinale cultivation facility, reveal the yield and functional components variation of stereoscopic cultivated D. officinale, and improve quality, yield and efficiency. The agronomic traits and yield variation of stereoscopic cultivated D. officinale were studied by operating field experiment. The content of polysaccharide and extractum were determined by using phenol-sulfuric acid method and 2010 edition of "Chinese Pharmacopoeia" Appendix X A. The results showed that the land utilization of stereoscopic cultivated D. officinale increased 2.74 times, the stems, leaves and their total fresh or dry weight in unit area of stereoscopic cultivated D. officinale were all heavier than those of the ground cultivated ones. There was no significant difference in polysaccharide content between stereoscopic cultivation and ground cultivation. But the extractum content and total content of polysaccharide and extractum were significantly higher than those of the ground cultivated ones. In additional, the polysaccharide content and total content of polysaccharide and extractum from the top two levels of stereoscopic culture matrix were significantly higher than that of the ones from the other levels and ground cultivation. Steroscopic cultivation can effectively improves the utilization of space and yield, while the total content of polysaccharides and extractum were significantly higher than that of the ground cultivated ones. The significant difference in Dendrobium polysaccharides among the plants from different height of stereo- scopic culture matrix may be associated with light factor. PMID:25911804

  3. 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.

  4. Are Instant Messages Speech?

    NASA Astrophysics Data System (ADS)

    Baron, Naomi S.

    Instant messaging (IM) is commonly viewed as a “spoken” medium, in light of its reputation for informality, non-standard spelling and punctuation, and use of lexical shortenings and emoticons. However, the actual nature of IM is an empirical issue that bears linguistic analysis.

  5. 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…

  6. 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…

  7. 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

  8. 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

  9. 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. PMID:24832595

  10. A rotational stereoscopic 3-dimensional movement aftereffect.

    PubMed

    Webster, W R; Panthradil, J T; Conway, D M

    1998-06-01

    A stereoscopic rotational movement aftereffect (MAE) and a stereoscopic bi-directional MAE were generated by rotation of a cyclopean random dot cylinder in depth and by movement of two cyclopean random dot planes in opposite directions, respectively. Cross-adaptational MAEs were also generated on each other, but not with stimuli lacking any disparity. Cross-adaptation MAEs were generated between stereoscopic and non-stereoscopic random dot stimuli moving in the one X/Y plane. Spontaneous reversals in direction of movement were observed with bistable stimuli lacking disparity. Two models of the middle temporal area were considered which might explain both the stereoscopic MAEs and the spontaneous reversals. PMID:9797953

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Stereoscopic medical data video quality issues.

    PubMed

    Patrona, Foteini; Mademlis, Ioannis; Kalaganis, Fotios; Pitas, Ioannis; Lyroudia, Kleoniki

    2016-04-01

    Stereoscopic medical videos are recorded, e.g., in stereo endoscopy or during video recording medical/dental operations. This paper examines quality issues in the recorded stereoscopic medical videos, as insufficient quality may induce visual fatigue to doctors. No attention has been paid to stereo quality and ensuing fatigue issues in the scientific literature so far. Two of the most commonly encountered quality issues in stereoscopic data, namely stereoscopic window violations and bent windows, were searched for in stereo endoscopic medical videos. Furthermore, an additional stereo quality issue encountered in dental operation videos, namely excessive disparity, was detected and fixed. The conducted experiments prove the existence of such quality issues in stereoscopic medical data and highlight the need for their detection and correction. PMID:27284549

  16. 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.

  17. 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.

  18. Brief history of electronic stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Lipton, Lenny

    2012-02-01

    A brief history of recent developments in electronic stereoscopic displays is given concentrating on products that have succeeded in the market place and hence have had a significant influence on future implementations. The concentration is on plano-stereoscopic (two-view) technology because it is now the dominant display modality in the marketplace. Stereoscopic displays were created for the motion picture industry a century ago, and this technology influenced the development of products for science and industry, which in turn influenced product development for entertainment.

  19. Interactive stereoscopic rendering of volumetric environments.

    PubMed

    Wan, Ming; Zhang, Nan; Qu, Huamin; Kaufman, Arie E

    2004-01-01

    We present an efficient stereoscopic rendering algorithm supporting interactive navigation through large-scale 3D voxel-based environments. In this algorithm, most of the pixel values of the right image are derived from the left image by a fast 3D warping based on a specific stereoscopic projection geometry. An accelerated volumetric ray casting then fills the remaining gaps in the warped right image. Our algorithm has been parallelized on a multiprocessor by employing effective task partitioning schemes and achieved a high cache coherency and load balancing. We also extend our stereoscopic rendering to include view-dependent shading and transparency effects. We have applied our algorithm in two virtual navigation systems, flythrough over terrain and virtual colonoscopy, and reached interactive stereoscopic rendering rates of more than 10 frames per second on a 16-processor SGI Challenge. PMID:15382695

  20. Stereoscopic Projection of 35mm Slides.

    ERIC Educational Resources Information Center

    Carey, Edward F.

    1978-01-01

    Describes ways of projecting stereoscopic images of geologic environments for students with difficulty reasoning in three-dimensions. The photographic procedures needed to produce stereo slides are included. (MA)

  1. Original and creative stereoscopic film making

    NASA Astrophysics Data System (ADS)

    Criado, Enrique

    2008-02-01

    The stereoscopic cinema has become, once again, a hot topic in the film production. For filmmakers to be successful in this field, a technical background in the principles of binocular perception and how our brain interprets the incoming data from our eyes, are fundamental. It is also paramount for a stereoscopic production to adhere certain rules for comfort and safety. There is an immense variety of options in the art of standard "flat" photography, and the possibilities only can be multiply with the stereo. The stereoscopic imaging has its own unique areas for subjective, original and creative control that allow an incredible range of possible combinations by working inside the standards, and in some cases on the boundaries of the basic stereo rules. The stereoscopic imaging can be approached in a "flat" manner, like channeling sound through an audio equalizer with all the bands at the same level. It can provide a realistic perception, which in many cases can be sufficient, thanks to the rock-solid viewing inherent to the stereoscopic image, but there are many more possibilities. This document describes some of the basic operating parameters and concepts for stereoscopic imaging, but it also offers ideas for a creative process based on the variation and combination of these basic parameters, which can lead into a truly innovative and original viewing experience.

  2. Instant Messaging: IM Online! RU?

    ERIC Educational Resources Information Center

    Farmer, Robert

    2005-01-01

    This article discusses the technology of instant messaging (IM), a relatively simple form of communication. It is also--by its very nature--a collaborative communications tool. This collaborative nature is what makes IM ideal for educational and learning environments. With IM playing such a large role in the communication, interactivity, and…

  3. Saliency prediction on stereoscopic videos.

    PubMed

    Kim, Haksub; Lee, Sanghoon; Bovik, Alan Conrad

    2014-04-01

    We describe a new 3D saliency prediction model that accounts for diverse low-level luminance, chrominance, motion, and depth attributes of 3D videos as well as high-level classifications of scenes by type. The model also accounts for perceptual factors, such as the nonuniform resolution of the human eye, stereoscopic limits imposed by Panum's fusional area, and the predicted degree of (dis) comfort felt, when viewing the 3D video. The high-level analysis involves classification of each 3D video scene by type with regard to estimated camera motion and the motions of objects in the videos. Decisions regarding the relative saliency of objects or regions are supported by data obtained through a series of eye-tracking experiments. The algorithm developed from the model elements operates by finding and segmenting salient 3D space-time regions in a video, then calculating the saliency strength of each segment using measured attributes of motion, disparity, texture, and the predicted degree of visual discomfort experienced. The saliency energy of both segmented objects and frames are weighted using models of human foveation and Panum's fusional area yielding a single predictor of 3D saliency. PMID:24565790

  4. Outcome Evaluation of the Instant Word Notebook

    ERIC Educational Resources Information Center

    Bland, Adrienne Lynn

    2012-01-01

    The Instant Word Notebook study was a program evaluation completed by two educators who saw a need for an instructional tool to teach and assess Instant Words. In order to address reading deficits of students in first and second grades, teachers were expected to teach Instant Words. Unfortunately, teachers did not have a systematic process to…

  5. 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

  6. Two Eyes, 3D: Stereoscopic Design Principles

    NASA Astrophysics Data System (ADS)

    Price, Aaron; Subbarao, M.; Wyatt, R.

    2013-01-01

    Two Eyes, 3D is a NSF-funded research project about how people perceive highly spatial objects when shown with 2D or stereoscopic ("3D") representations. As part of the project, we produced a short film about SN 2011fe. The high definition film has been rendered in both 2D and stereoscopic formats. It was developed according to a set of stereoscopic design principles we derived from the literature and past experience producing and studying stereoscopic films. Study participants take a pre- and post-test that involves a spatial cognition assessment and scientific knowledge questions about Type-1a supernovae. For the evaluation, participants use iPads in order to record spatial manipulation of the device and look for elements of embodied cognition. We will present early results and also describe the stereoscopic design principles and the rationale behind them. All of our content and software is available under open source licenses. More information is at www.twoeyes3d.org.

  7. 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.

  8. No-reference stereoscopic image quality assessment

    NASA Astrophysics Data System (ADS)

    Akhter, Roushain; Parvez Sazzad, Z. M.; Horita, Y.; Baltes, J.

    2010-02-01

    Display of stereo images is widely used to enhance the viewing experience of three-dimensional imaging and communication systems. In this paper, we propose a method for estimating the quality of stereoscopic images using segmented image features and disparity. This method is inspired by the human visual system. We believe the perceived distortion and disparity of any stereoscopic display is strongly dependent on local features, such as edge (non-plane) and non-edge (plane) areas. Therefore, a no-reference perceptual quality assessment is developed for JPEG coded stereoscopic images based on segmented local features of artifacts and disparity. Local feature information such as edge and non-edge area based relative disparity estimation, as well as the blockiness and the blur within the block of images are evaluated in this method. Two subjective stereo image databases are used to evaluate the performance of our method. The subjective experiments results indicate our model has sufficient prediction performance.

  9. 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.

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. Stereoscopic contents authoring system for 3D DMB data service

    NASA Astrophysics Data System (ADS)

    Lee, BongHo; Yun, Kugjin; Hur, Namho; Kim, Jinwoong; Lee, SooIn

    2009-02-01

    This paper presents a stereoscopic contents authoring system that covers the creation and editing of stereoscopic multimedia contents for the 3D DMB (Digital Multimedia Broadcasting) data services. The main concept of 3D DMB data service is that, instead of full 3D video, partial stereoscopic objects (stereoscopic JPEG, PNG and MNG) are stereoscopically displayed on the 2D background video plane. In order to provide stereoscopic objects, we design and implement a 3D DMB content authoring system which provides the convenient and straightforward contents creation and editing functionalities. For the creation of stereoscopic contents, we mainly focused on two methods: CG (Computer Graphics) based creation and real image based creation. In the CG based creation scenario where the generated CG data from the conventional MAYA or 3DS MAX tool is rendered to generate the stereoscopic images by applying the suitable disparity and camera parameters, we use X-file for the direct conversion to stereoscopic objects, so called 3D DMB objects. In the case of real image based creation, the chroma-key method is applied to real video sequences to acquire the alpha-mapped images which are in turn directly converted to stereoscopic objects. The stereoscopic content editing module includes the timeline editor for both the stereoscopic video and stereoscopic objects. For the verification of created stereoscopic contents, we implemented the content verification module to verify and modify the contents by adjusting the disparity. The proposed system will leverage the power of stereoscopic contents creation for mobile 3D data service especially targeted for T-DMB with the capabilities of CG and real image based contents creation, timeline editing and content verification.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Three-Dimensional Pointers for Stereoscopic Projection.

    ERIC Educational Resources Information Center

    Hayman, H. J. G.

    1984-01-01

    Because class size often limits student opportunity to handle individual models, teachers use stereoscopic projections to demonstrate structural features. Describes three-dimensional pointers for use with different projection systems so teachers can indicate a particular atom or bond to entire classes, avoiding the perspective problems inherent in…

  1. Stereoscopic Investigations of 3D Coulomb Balls

    SciTech Connect

    Kaeding, Sebastian; Melzer, Andre; Arp, Oliver; Block, Dietmar; Piel, Alexander

    2005-10-31

    In dusty plasmas particles are arranged due to the influence of external forces and the Coulomb interaction. Recently Arp et al. were able to generate 3D spherical dust clouds, so-called Coulomb balls. Here, we present measurements that reveal the full 3D particle trajectories from stereoscopic imaging.

  2. General stereoscopic distortion rectification due to arbitrary viewer motion in binocular stereoscopic display

    NASA Astrophysics Data System (ADS)

    Li, Qun; Schonfeld, Dan

    2014-03-01

    Background: In binocular stereoscopic display, stereoscopic distortions due to viewer motion, such as depth distortion, shear distortion, and rotation distortion, result in misperception of the stereo content and reduce visual comfort dramat­ ically. In the past, perceived depth distortion has been thoroughly addressed, and shear distortion has been investigated within the context of multi-view display to accommodate motion parallax. However, the impact of rotation distortion has barely been studied. Therefore, no technique is available to address stereoscopic distortions due to general viewer motion. Objective: To preserve an undistorted 3D perception from a fixed viewpoint irrespective of viewing position. Method: We propose a unified system and method that rectifies stereoscopic distortion due to general affine viewer motion and delivers a fixed perspective of the 3D scene without distortion irrespective of viewer motion. The system assumes eye tracking of the viewer and pixel-wisely adjusts the display location of the stereo pair based on tracked viewer eye location. Results: For demonstration purpose, we implement our method on controlling perceived depth in binocular stereoscopic display of red and cyan anaglyph 3D. The user first perceives the designed perspective of the 3D scene at the reference position. The user then moves to 6 different positions with various distances and angles relative to the screen. At all positions, the users report to perceive a much more consistent stereo content with the adjusted displays and at the same time, experience improved visual comfort. Novelty: We address stereoscopic distortions with a goal to maintain a fixed perspective of the stereo scene, and propose a unified solution that simultaneously rectifies the stereoscopic distortions resulted from arbitrary viewer motion.

  3. 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

  4. Process Evaluation of the Instant Word Notebook

    ERIC Educational Resources Information Center

    Roberts, Jeannie Ellen

    2010-01-01

    This program evaluation of The Instant Word Notebook was conducted by two educators who created an instructional tool to teach and assess the most frequently occurring words in written text, commonly known as Instant Words. In an effort to increase the reading scores of first and second grade students, teachers were instructed to teach Instant…

  5. 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…

  6. Should We Ban Instant Messaging In School?

    ERIC Educational Resources Information Center

    Texley, Sharon; DeGennaro, Donna

    2005-01-01

    This article is a brief debate on the pros and cons of allowing students to use instant messaging (IM) in school. On one hand, teenagers' desire to socialize can overcome other priorities and schools may set policies to ban instant messaging. The contrary view is that schools should embrace the IM technology being popularized by youth and find…

  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. Experiments on shape perception in stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Leroy, Laure; Fuchs, Philippe; Paljic, Alexis; Moreau, Guillaume

    2009-02-01

    Stereoscopic displays are increasingly used for computer-aided design. The aim is to make virtual prototypes to avoid building real ones, so that time, money and raw materials are saved. But do we really know whether virtual displays render the objects in a realistic way to potential users? In this study, we have performed several experiments in which we compare two virtual shapes to their equivalent in the real world, each of these aiming at a specific issue by a comparison: First, we performed some perception tests to evaluate the importance of head tracking to evaluate if it is better to concentrate our efforts on stereoscopic vision; Second, we have studied the effects of interpupillary distance; Third, we studied the effects of the position of the main object in comparison with the screen. Two different tests are used, the first one using a well-known shape (a sphere) and the second one using an irregular shape but with almost the same colour and dimension. These two tests allow us to determine if symmetry is important in their perception. We show that head tracking has a more important effect on shape perception than stereoscopic vision, especially on depth perception because the subject is able to move around the scene. The study also shows that an object between the subject and the screen is perceived better than an object which is on the screen, even if the latter is better for the eye strain.

  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. Stereoscopic image quality assessment using disparity-compensated view filtering

    NASA Astrophysics Data System (ADS)

    Song, Yang; Yu, Mei; Jiang, Gangyi; Shao, Feng; Peng, Zongju

    2016-03-01

    Stereoscopic image quality assessment (IQA) plays a vital role in stereoscopic image/video processing systems. We propose a new quality assessment for stereoscopic image that uses disparity-compensated view filtering (DCVF). First, because a stereoscopic image is composed of different frequency components, DCVF is designed to decompose it into high-pass and low-pass components. Then, the qualities of different frequency components are acquired according to their phase congruency and coefficient distribution characteristics. Finally, support vector regression is utilized to establish a mapping model between the component qualities and subjective qualities, and stereoscopic image quality is calculated using this mapping model. Experiments on the LIVE 3-D IQA database and NBU 3-D IQA databases demonstrate that the proposed method can evaluate stereoscopic image quality accurately. Compared with several state-of-the-art quality assessment methods, the proposed method is more consistent with human perception.

  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. Measuring stereoscopic image quality experience with interpretation based quality methodology

    NASA Astrophysics Data System (ADS)

    Häkkinen, Jukka; Kawai, Takashi; Takatalo, Jari; Leisti, Tuomas; Radun, Jenni; Hirsaho, Anni; Nyman, Göte

    2008-01-01

    Stereoscopic technologies have developed significantly in recent years. These advances require also more understanding of the experiental dimensions of stereoscopic contents. In this article we describe experiments in which we explore the experiences that viewers have when they view stereoscopic contents. We used eight different contents that were shown to the participants in a paired comparison experiment where the task of the participants was to compare the same content in stereoscopic and non-stereoscopic form. The participants indicated their preference but were also interviewed about the arguments they used when making the decision. By conducting a qualitative analysis of the interview texts we categorized the significant experiental factors related to viewing stereoscopic material. Our results indicate that reality-likeness as well as artificiality were often used as arguments in comparing the stereoscopic materials. Also, there were more emotional terms in the descriptions of the stereoscopic films, which might indicate that the stereoscopic projection technique enhances the emotions conveyed by the film material. Finally, the participants indicated that the three-dimensional material required longer presentation time, as there were more interesting details to see.

  15. Human factors involved in perception and action in a natural stereoscopic world: an up-to-date review with guidelines for stereoscopic displays and stereoscopic virtual reality (VR)

    NASA Astrophysics Data System (ADS)

    Perez-Bayas, Luis

    2001-06-01

    In stereoscopic perception of a three-dimensional world, binocular disparity might be thought of as the most important cue to 3D depth perception. Nevertheless, in reality there are many other factors involved before the 'final' conscious and subconscious stereoscopic perception, such as luminance, contrast, orientation, color, motion, and figure-ground extraction (pop-out phenomenon). In addition, more complex perceptual factors exist, such as attention and its duration (an equivalent of 'brain zooming') in relation to physiological central vision, In opposition to attention to peripheral vision and the brain 'top-down' information in relation to psychological factors like memory of previous experiences and present emotions. The brain's internal mapping of a pure perceptual world might be different from the internal mapping of a visual-motor space, which represents an 'action-directed perceptual world.' In addition, psychological factors (emotions and fine adjustments) are much more involved in a stereoscopic world than in a flat 2D-world, as well as in a world using peripheral vision (like VR, using a curved perspective representation, and displays, as natural vision does) as opposed to presenting only central vision (bi-macular stereoscopic vision) as in the majority of typical stereoscopic displays. Here is presented the most recent and precise information available about the psycho-neuro- physiological factors involved in the perception of stereoscopic three-dimensional world, with an attempt to give practical, functional, and pertinent guidelines for building more 'natural' stereoscopic displays.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Instant noodles: processing, quality, and nutritional aspects.

    PubMed

    Gulia, Neelam; Dhaka, Vandana; Khatkar, B S

    2014-01-01

    Noodles are one of the staple foods consumed in many Asian countries. Instant noodles have become internationally recognized food, and worldwide consumption is on the rise. The properties of instant noodles like taste, nutrition, convenience, safety, longer shelf-life, and reasonable price have made them popular. Quality factors important for instant noodles are color, flavor, and texture, cooking quality, rehydration rates during final preparation, and the presence or absence of rancid taste after extended storage. Microstructure of dough and noodles has been studied to understand the influence of ingredients and processing variables on the noodle quality by employing scanning electron microscopy. Applications of newer techniques like confocal laser scanning microscopy and epifluorescence light microscopy employed to understand the microstructure changes in dough and noodles have also been discussed. Sincere efforts of researchers are underway to improve the formulation, extend the shelf life, and promote universal fortification of instant noodles. Accordingly, many researchers are exploring the potential of noodle fortification as an effective public health intervention and improve its nutritional properties. This review focuses on the functionality of ingredients, unit operations involved, quality criteria for evaluation, recent trends in fortification, and current knowledge in relation to instant noodles. PMID:24564594

  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. Quality Prediction of Asymmetrically Distorted Stereoscopic 3D Images.

    PubMed

    Wang, Jiheng; Rehman, Abdul; Zeng, Kai; Wang, Shiqi; Wang, Zhou

    2015-11-01

    Objective quality assessment of distorted stereoscopic images is a challenging problem, especially when the distortions in the left and right views are asymmetric. Existing studies suggest that simply averaging the quality of the left and right views well predicts the quality of symmetrically distorted stereoscopic images, but generates substantial prediction bias when applied to asymmetrically distorted stereoscopic images. In this paper, we first build a database that contains both single-view and symmetrically and asymmetrically distorted stereoscopic images. We then carry out a subjective test, where we find that the quality prediction bias of the asymmetrically distorted images could lean toward opposite directions (overestimate or underestimate), depending on the distortion types and levels. Our subjective test also suggests that eye dominance effect does not have strong impact on the visual quality decisions of stereoscopic images. Furthermore, we develop an information content and divisive normalization-based pooling scheme that improves upon structural similarity in estimating the quality of single-view images. Finally, we propose a binocular rivalry-inspired multi-scale model to predict the quality of stereoscopic images from that of the single-view images. Our results show that the proposed model, without explicitly identifying image distortion types, successfully eliminates the prediction bias, leading to significantly improved quality prediction of the stereoscopic images. PMID:26087491

  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. 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.

  5. Spatial distortion prediction system for stereoscopic images

    NASA Astrophysics Data System (ADS)

    Masaoka, Kenichiro; Hanazato, Atsuo; Emoto, Masaki; Yamanoue, Hirokazu; Nojiri, Yuji; Okano, Fumio

    2006-01-01

    We propose a system to calculate the spatial distortion in 3-D images based on the shooting, display, and viewing conditions. It can be used to predict the extent of the perceived puppet-theater effect and the cardboard effect. The magnitude of the spatial distortion and the extent of the puppet-theater and cardboard effects are displayed using a space grid whose size can be estimated based on the objects' depths, calculated from the binocular parallax of the acquired stereoscopic images. This system can also be used to predict excessive binocular parallax and excessive parallax distribution. Several cases in which puppet-theater and cardboard effects are expected to be produced are presented. We also demonstrate how the proposed system might be used to predict ratings of naturalness and quality of depth.

  6. 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...

  7. Creating an Instant Messaging Reference System.

    ERIC Educational Resources Information Center

    Fagan, Jody Condit; Calloway, Michele

    2001-01-01

    Discussion of library digital reference services focuses on the features of instant messaging reference systems and the in-house development of a system that incorporates them at Southern Illinois University at Carbondale. Summarizes and evaluates library chat system features and compares commercial software that is available. (Author/LRW)

  8. 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…

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Wheatstone and the origins of moving stereoscopic images.

    PubMed

    Wade, Nicholas J

    2012-01-01

    The recent resurgence of stereoscopic films and television programmes occasions reflection on their origins. Experimental studies of stroboscopic (apparent) motion and stereoscopic vision have their origins in London in the decade from 1825 to 1835. Instruments were devised which simulated motion and depth: sequences of still images could appear to move, and paired pictures (with small horizontal disparities and presented to different eyes) were seen in depth. Until that time, the experience of motion was almost always a consequence of object or observer movement: apparent motion was a novelty. By contrast, stereoscopic vision was the near-universal experience of using two eyes in the natural environment, but its basis remained mysterious. The stereoscope rendered the normal conditions for seeing depth from disparity experimentally tractable. The instruments were called philosophical toys because they fulfilled the dual roles of furthering scientific experiment on the senses and of providing popular amusement. The investigations were initially driven by the need for stimulus control so that the methods of physics could be applied to the study of perceptual phenomena. Many varieties of stroboscopic discs and stereoscopes were devised thereafter and their popularity increased enormously after 1840, when combined with photography. Presenting sequences of stereoscopic photographs in apparent motion was attempted in the 1850s, but proved less successful. The catalyst involved in all these developments was Charles Wheatstone. PMID:23362669

  14. 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.

  15. 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

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. Field-Sequential Electronic Stereoscopic Projector

    NASA Astrophysics Data System (ADS)

    Lipton, Lenny

    1989-07-01

    Culminating a research and development project spanning many years, StereoGraphics Corporation has succeeded in bringing to market the first field-sequential electronic stereoscopic projector. The product is based on a modification of Electrohome and Barco projectors. Our design goal was to produce a projector capable of displaying an image on a six-foot (or larger) diagonal screen for an audience of 50 or 60 people, or for an individual using a simulator. A second goal was to produce an image that required only passive polarizing glasses rather than powered, tethered visors. Two major design challenges posed themselves. First, it was necessary to create an electro-optical modulator which could switch the characteristic of polarized light at field rate, and second, it was necessary to produce a bright green CRT with short persistence to prevent crosstalk between left and right fields. To solve the first problem, development was undertaken to produce the required electro-optical modulator. The second problem was solved with the help of a vendor specializing in high performance CRT's.

  2. 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.

  3. A 3-D mixed-reality system for stereoscopic visualization of medical dataset.

    PubMed

    Ferrari, Vincenzo; Megali, Giuseppe; Troia, Elena; Pietrabissa, Andrea; Mosca, Franco

    2009-11-01

    We developed a simple, light, and cheap 3-D visualization device based on mixed reality that can be used by physicians to see preoperative radiological exams in a natural way. The system allows the user to see stereoscopic "augmented images," which are created by mixing 3-D virtual models of anatomies obtained by processing preoperative volumetric radiological images (computed tomography or MRI) with real patient live images, grabbed by means of cameras. The interface of the system consists of a head-mounted display equipped with two high-definition cameras. Cameras are mounted in correspondence of the user's eyes and allow one to grab live images of the patient with the same point of view of the user. The system does not use any external tracker to detect movements of the user or the patient. The movements of the user's head and the alignment of virtual patient with the real one are done using machine vision methods applied on pairs of live images. Experimental results, concerning frame rate and alignment precision between virtual and real patient, demonstrate that machine vision methods used for localization are appropriate for the specific application and that systems based on stereoscopic mixed reality are feasible and can be proficiently adopted in clinical practice. PMID:19651551

  4. [Microbiologic evaluation of instant soup concentrates].

    PubMed

    Wójcik-Stopczyńska, Barbara; Falkowski, Joachim; Jakubowska, Barbara

    2002-01-01

    The microbiological condition of instant soup powders purchased in retail network has been assessed. The study included 37 instant soups (8 types) manufactured by four Polish companies. The microbiological quality of a majority of soup powders fulfilled the requirements of the standard. No pathogenic bacteria (Salmonella, E. coli and Staphylococcus aureus) were detected, nor were there any spores of sulphitereducing anaerobic bacteria found. However, some samples of powders, mainly from one manufacturer, did have an excessive total number of bacteria (> 10(5) cfu/g) and a reduced (down to 0.01 g) level of coliform count. Aerobic bacteria occurring in powders were of vegetative and spore forms and exhibited the activity of amylo-, lipo- and proteolytic exoenzymes. The quantity of moulds did not exceed 100 cfu/g in a majority of samples. They were mainly represented by Penicillium sp., Aspergillus sp., Alternaria sp. and Cladosporium sp. PMID:12235671

  5. 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.

  6. 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

  7. 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.

  8. Stereoscopic Integrated Imaging Goggles for Multimodal Intraoperative Image Guidance.

    PubMed

    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, PMID:26529249

  9. 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

  10. 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

  11. 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

  12. 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.

  13. Design of stereoscopic display monitor for multi-users

    NASA Astrophysics Data System (ADS)

    Liu, Qing; Zhang, Yuncui; Liu, Long; Zou, Nianyu; Cao, Guanying; Dong, Xiaomei

    2011-12-01

    A new naked eyes stereoscopic display optical system for multi-users was proposed in this paper, different from the conventional naked eyes stereoscopic display monitors with sophistication technology and bad uniformity of illumination. According to the binocular parallax technology, Fresnel lens and polaroid sheet were chosen to focus the rays on the observers' eyes. Freeform lens were used in this system to enhance illumination uniformity of pictures and efficiency of the system. The results of simulation showed that the users can obtain stereoscopic effect at their each places, uniformity of illumination on LCD was above 0.6. Therefore, this system had a simple and compact structure, and the quality of pictures users obtain was better than system without freeform lenses.

  14. Cosmic cookery: making a stereoscopic 3D animated movie

    NASA Astrophysics Data System (ADS)

    Holliman, Nick; Baugh, Carlton; Frenk, Carlos; Jenkins, Adrian; Froner, Barbara; Hassaine, Djamel; Helly, John; Metcalfe, Nigel; Okamoto, Takashi

    2006-02-01

    This paper describes our experience making a short stereoscopic movie visualizing the development of structure in the universe during the 13.7 billion years from the Big Bang to the present day. Aimed at a general audience for the Royal Society's 2005 Summer Science Exhibition, the movie illustrates how the latest cosmological theories based on dark matter and dark energy are capable of producing structures as complex as spiral galaxies and allows the viewer to directly compare observations from the real universe with theoretical results. 3D is an inherent feature of the cosmology data sets and stereoscopic visualization provides a natural way to present the images to the viewer, in addition to allowing researchers to visualize these vast, complex data sets. The presentation of the movie used passive, linearly polarized projection onto a 2m wide screen but it was also required to playback on a Sharp RD3D display and in anaglyph projection at venues without dedicated stereoscopic display equipment. Additionally lenticular prints were made from key images in the movie. We discuss the following technical challenges during the stereoscopic production process; 1) Controlling the depth presentation, 2) Editing the stereoscopic sequences, 3) Generating compressed movies in display specific formats. We conclude that the generation of high quality stereoscopic movie content using desktop tools and equipment is feasible. This does require careful quality control and manual intervention but we believe these overheads are worthwhile when presenting inherently 3D data as the result is significantly increased impact and better understanding of complex 3D scenes.

  15. Content- and disparity-adaptive stereoscopic image retargeting

    NASA Astrophysics Data System (ADS)

    Yan, Weiqing; Hou, Chunping; Zhou, Yuan; Xiang, Wei

    2016-02-01

    The paper proposes a content- and disparity-adaptive stereoscopic image retargeting. To simultaneously avoid the saliency content and disparity distortion, firstly, we calculate the image saliency region distortion difference, and conclude the factors causing visual distortion. Then, the proposed method via a convex quadratic programming can simultaneously avoid the distortion of the salient region and adjust disparity to a target area, by considering the relationship of the scaling factor of salient region and the disparity scaling factor. The experimental results show that the proposed method is able to successfully adapt the image disparity to the target display screen, while the salient objects remain undistorted in the retargeted stereoscopic image.

  16. 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.

  17. Increasing Range Of Apparent Depth In A Stereoscopic Display

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

    1995-01-01

    Optical configuration conceived for increasing range of apparent depth provided by stereoscopic display system, without imposing concomitant reduction in field of view. Observer wears shuttered goggles synchronized with alternating left- and right-eye views on display. However, instead of looking directly at display screen, observer looks at screen via reflection in mirror collimating light emitted by screen.

  18. 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.

  19. 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.

  20. 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.

  1. 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…

  2. 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.

  3. Stereoscopic displays in medical domains: a review of perception and performance effects

    NASA Astrophysics Data System (ADS)

    van Beurden, Maurice H. P. H.; van Hoey, Gert; Hatzakis, Haralambos; Ijsselsteijn, Wijnand A.

    2009-02-01

    In this paper we review empirical studies that investigate performance effects of stereoscopic displays for medical applications. We focus on four distinct application areas: diagnosis, pre-operative planning, minimally invasive surgery (MIS) and training/teaching. For diagnosis, stereoscopic displays can augment the understanding of complex spatial structures and increase the detection of abnormalities. Stereoscopic viewing of medical data has proven to increase the detection rate in breast imaging. A stereoscopic presentation of noisy and transparent images in 3D ultrasound results in better visualization of the internal structures, however more empirical studies are needed to confirm the clinical relevance. For MRI and CT, where images are frequently rendered in 3D perspective, the added value of binocular depth has not yet been convincingly demonstrated. For MIS, stereoscopic displays can decrease surgery time and increase accuracy of surgical procedures. Performance of surgical procedures is similar when high resolution 2D displays are compared with lower resolution stereoscopic displays, indicating an image quality improvement for stereoscopic displays. Training and surgical planning already use computer simulations in 2D, however more research is needed to the benefit of stereoscopic displays in those applications. Overall there is a clear need for more empirical evidence that quantifies the added value of stereoscopic displays in medical domains, such that the medical community will have ample basis to invest in stereoscopic displays in all or some of the described medical applications.

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

    PubMed

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

    2011-10-01

    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

  5. Balance and coordination after viewing stereoscopic 3D television.

    PubMed

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

    2015-07-01

    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

  6. 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

  7. Clinical Assessment of a New Stereoscopic Digital Angiography System

    SciTech Connect

    Moll, Thierry; Douek, Philippe; Finet, Gerard; Turjman, Francis; Picard, Catherine; Revel, Didier; Amiel, Michel

    1998-01-15

    Purpose: To assess the clinical feasibility of an experimental modified angiographic system capable of real-time digital stereofluoroscopy and stereography in X-ray angiography, using a twin-focus tube and a stereoscopic monitor. Methods: We report the experience obtained in 37 patients with a well-documented examination. The patients were examined for coronary angiography (11 cases), aortography (7 cases), pulmonary angiography (6 cases), inferior vena cava filter placement (2 cases), and cerebral angiography (11 cases). Six radiologists were asked to use stereoscopic features for fluoroscopy and angiography. A questionnaire was designed to record their subjective evaluation of stereoscopic image quality, ergonomics of the system, and its medical interest. Results: Stereofluoroscopy was successfully used in 25 of 37 cases; diplopia and/or ghost images were reported in 6 cases. It was helpful for aortic catheterization in 10 cases and for selective catheterization in 5 cases. In stereoangiography, depth was easily and accurately perceived in 27 of 37 cases; diplopia and/or ghost images were reported in 4 cases. A certain gain in the three-dimensional evaluation of the anatomy and relation between vessels and lesions was noted. As regards ergonomic considerations, polarized spectacles were not considered cumbersome. Visual fatigue and additional work were variously reported. Stereoshift tuning before X-ray acquisition was not judged to be a limiting factor. Conclusion: A twin-focus X-ray tube and a polarized shutter for stereoscopic display allowed effective real-time three-dimensional perception of angiographic images. Our clinical study suggests no clear medical interest for diagnostic examinations, but the field of interventional radiology needs to be investigated.

  8. 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.

  9. 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.

  10. 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.

  11. Architecture for high performance stereoscopic game rendering on Android

    NASA Astrophysics Data System (ADS)

    Flack, Julien; Sanderson, Hugh; Shetty, Sampath

    2014-03-01

    Stereoscopic gaming is a popular source of content for consumer 3D display systems. There has been a significant shift in the gaming industry towards casual games for mobile devices running on the Android™ Operating System and driven by ARM™ and other low power processors. Such systems are now being integrated directly into the next generation of 3D TVs potentially removing the requirement for an external games console. Although native stereo support has been integrated into some high profile titles on established platforms like Windows PC and PS3 there is a lack of GPU independent 3D support for the emerging Android platform. We describe a framework for enabling stereoscopic 3D gaming on Android for applications on mobile devices, set top boxes and TVs. A core component of the architecture is a 3D game driver, which is integrated into the Android OpenGL™ ES graphics stack to convert existing 2D graphics applications into stereoscopic 3D in real-time. The architecture includes a method of analyzing 2D games and using rule based Artificial Intelligence (AI) to position separate objects in 3D space. We describe an innovative stereo 3D rendering technique to separate the views in the depth domain and render directly into the display buffer. The advantages of the stereo renderer are demonstrated by characterizing the performance in comparison to more traditional render techniques, including depth based image rendering, both in terms of frame rates and impact on battery consumption.

  12. Measurement of perceived stereoscopic sensation through disparity metrics and compositions

    NASA Astrophysics Data System (ADS)

    Toyosawa, Satoshi; Kawai, Takashi

    2014-03-01

    Literatures use disparity as a principle measure evaluating discomfort, various artifacts, or movie production styles associated to stereoscopy, yet, statistics used to represent image or frame are often different. The current study examines 20 disparity statistics to find metrics that would best represent subjective stereoscopic sensation. Additionally, effect of disparity distribution pattern within an image is considered: Here, the patterns are categorised either single-peak or multiple-peak from the shape of disparity histogram. In the experiment, 14 stereoscopic images were presented to 15 subjects. Each subject evaluated perceived sense of distance and volume (3D space) through 7 points Likert scale. The result shows that the statistics that correlated significantly to the subjective sensation differed by the disparity compositions, hence, the metrics should be chosen accordingly. For the sense of distance, maximum, range, and the difference between 95th and 5th percentiles were found to be appropriate metrics under the single-peak, and minimum, contrast, and 5th percentile were representative under the multiple-peak. Similarly, for the sense of volume, range was found to be appropriate under the single-peak, but no metrics was found under the multiple-peak. The discrepancy is assumed due to different observation styles under differently composed images. We believe that the current study provides optimal disparity metrics for stereoscopic sensation measurements.

  13. Stereoscopic Displays And The Human Dual Visual System

    NASA Astrophysics Data System (ADS)

    Clapp, Robert E.

    1986-05-01

    There is only one real world. We "see" that world as extending into three dimensions because we look at it with two visual systems and with two eyes. We are not presented with two "pictures" of the real world, but with two separate sets of inputs into two separate systems. The analog of the eye as a camera has been a constant problem in the visualization of the "seeing" process. Overcoming the persistence of such an approach is the first requirement in developing a true stereoscopic display system. The eye is a dynamic sensing apparatus and supplies the brain with visual inputs. The brain constructs the scene we "see", and is responsible for our perceptions of the visual world. The sensory inputs from the human dual visual system (Ambient - wide FOV, Focal - detail FOV) are combined with other body senses in this perceptual process. Indeed, other body senses, in some degree, direct and control where and at what our eyes look. This process of conceptualization of the "real" world as perceived by ourselves can be related only within limits to the "real" world as perceived by others.. This paper addresses the processes by which our minds (with sensor inputs) work to form our stereoscopic perceptual concepts of the world, real or simulated, and the advantages (and problems) caused by our egocentric reduction of those data inputs. Discussion and evaluation of stereoscopic display systems compares current and future display systems.

  14. A composition tool for creating comfortable stereoscopic images

    NASA Astrophysics Data System (ADS)

    Quintus, Katharina; Halle, Michael

    2008-02-01

    Although stereoscopic imaging has potential value in many computer graphics applications, the design principles for creating effective three-dimensional images are not widely known in the graphics community. Poorly designed images may fail to convey convincing 3D information about the visualized scene or object. At their worst, stereo images designed without attention to physiological limits can produce the kinds of eye strain, headaches, and generally unpleasant viewing experiences that are unfortunately now associated with 3D by many people. This paper presents a graphical software application that assists the user in composing stereoscopic computer graphic images that minimize conflicting depth cues and unwanted physiological effects. This prototype application is designed to help novice users adjust parameters of the virtual stereo camera and compose stereoscopic views of three-dimensional models. Specifically, the tool detects window violations and excessive disparity, graphically displays affected regions of the object or scene, and suggests ways to minimize discomfort. The user interface refrains from using technical terms, guiding the inexperienced user to adjust underlying image parameters like camera position, camera view angle, location of image plane, viewing distance, and stereo base to match the scene, the viewing environment, and the user's preferences.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Interactive stereoscopic visualization of large-scale astrophysical simulations

    NASA Astrophysics Data System (ADS)

    Kaehler, Ralf; Abel, Tom

    2012-03-01

    In the last decades three-dimensional, time-dependent numerical simulations have become a standard tool in astrophysics and cosmology. This gave rise to a growing demand for analysis methods that are tailored to this type of simulation data, for example high-quality visualization approaches such as direct volume rendering and the display of stream lines. The modelled phenomena in numerical astrophysics usually involve complex spatial and temporal structures, and stereoscopic display techniques have proven to be particularly beneficial to clarify the spatial relationships of the relevant features. In this paper we present a flexible software framework for interactive stereoscopic visualizations of large time-dependent, three-dimensional astrophysical and cosmological simulation datasets. It is designed to enable fast and intuitive creation of complete rendering workflows, from importing datasets, the definition of various parameters, including camera paths and stereoscopic settings, to the storage of the final images in various output formats. It leverages the power of modern graphics processing units (GPUs) and supports high-quality floating-point precision throughout the whole rendering pipeline. All functionality is scriptable through Javascript. We give several application examples, including sequences produced for a number of planetarium shows.

  20. Construction of an instant structured illumination microscope.

    PubMed

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

    2015-10-15

    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

  1. 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

  2. Stereoscopic full aperture imaging in nuclear medicine

    NASA Astrophysics Data System (ADS)

    Strocovsky, Sergio G.; Otero, Dino

    2011-06-01

    Images of planar scintigraphy and single photon emission computerized tomography (SPECT) used in nuclear medicine are often low quality. They usually appear to be blurred and noisy. This problem is due to the low spatial resolution and poor sensitivity of the acquisition technique with the gamma camera (GC). Other techniques, such as coded aperture imaging (CAI) reach higher spatial resolutions than GC. However, CAI is not frequently used for imaging in nuclear medicine, due to the decoding complexity of some images and the difficulty in controlling the noise magnitude. Summing up, the images obtained through GC are low quality and it is still difficult to implement CAI technique. A novel technique, full aperture Imaging (FAI), also uses gamma ray-encoding to obtain images, but the coding system and the method of images reconstruction are simpler than those used in CAI. In addition, FAI also reaches higher spatial resolution than GC. In this work, the principles of FAI technique and the method of images reconstruction are explained in detail. The FAI technique is tested by means of Monte Carlo simulations with filiform and spherical sources. Spatial resolution tests of GC versus FAI were performed using two different source-detector distances. First, simulations were made without interposing any material between the sources and the detector. Then, other more realistic simulations were made. In these, the sources were placed in the centre of a rectangular prismatic region, filled with water. A rigorous comparison was made between GC and FAI images of the linear filiform sources, by means of two methods: mean fluence profile graphs and correlation tests. Finally, three-dimensional capacity of FAI was tested with two spherical sources. The results show that FAI technique has greater sensitivity (>100 times) and greater spatial resolution (>2.6 times) than that of GC with LEHR collimator, in both cases, with and without attenuating material and long and short

  3. [Electronic eikonometer: Measurement tests displayed on stereoscopic screen].

    PubMed

    Bourdy, C; James, Y

    2016-05-01

    We propose the presentation on a stereoscopic screen of the electronic eikonometer tests intended for analysis and measurement of perceptual effects of binocular disparity. These tests, so-called "built-in magnification tests" are constructed according to the same principle as those of preceding eikonometers (disparity variation parameters being included in each test presentation, which allows, for test observation and measurements during the examination, the removing of any intermediate optical system). The images of these tests are presented separately to each eye, according to active or passive stereoscopic screen technology: (1) Ogle Spatial Test to measure aniseikonia; (2) Fixation Disparity test: binocular nonius; (3) retinal correspondence test evaluated by nonius horopter; (4) stereoscopic test using Julesz' random-dot stereograms (RDS). All of these tests, with their variable parameters included, are preprogrammed by means of an associated mini-computer. This new system (a single screen for the presentation of tests for the right eye and left eye) will be much simpler to reproduce and install for all practitioners interested in the functional exploration of binocular vision. We develop the suitable methodology adapted to each type of examination, as well as manipulations to be performed by the operator. We then recall the possibilities for reducing aniseikonia thanks to some theoretical studies previously performed by matrix calculation of the size of the retinal images for different types of eye (emmetropia, axial or conformation anisometropia, aphakia) and for different means of correction (glasses, contact lenses, implants). Software for achieving these different tests is available, on request, at this address: eiconometre.electronique@gmail.com. PMID:27185662

  4. Parallax scanning methods for stereoscopic three-dimensional imaging

    NASA Astrophysics Data System (ADS)

    Mayhew, Christopher A.; Mayhew, Craig M.

    2012-03-01

    Under certain circumstances, conventional stereoscopic imagery is subject to being misinterpreted. Stereo perception created from two static horizontally separated views can create a "cut out" 2D appearance for objects at various planes of depth. The subject volume looks three-dimensional, but the objects themselves appear flat. This is especially true if the images are captured using small disparities. One potential explanation for this effect is that, although three-dimensional perception comes primarily from binocular vision, a human's gaze (the direction and orientation of a person's eyes with respect to their environment) and head motion also contribute additional sub-process information. The absence of this information may be the reason that certain stereoscopic imagery appears "odd" and unrealistic. Another contributing factor may be the absence of vertical disparity information in a traditional stereoscopy display. Recently, Parallax Scanning technologies have been introduced, which provide (1) a scanning methodology, (2) incorporate vertical disparity, and (3) produce stereo images with substantially smaller disparities than the human interocular distances.1 To test whether these three features would improve the realism and reduce the cardboard cutout effect of stereo images, we have applied Parallax Scanning (PS) technologies to commercial stereoscopic digital cinema productions and have tested the results with a panel of stereo experts. These informal experiments show that the addition of PS information into the left and right image capture improves the overall perception of three-dimensionality for most viewers. Parallax scanning significantly increases the set of tools available for 3D storytelling while at the same time presenting imagery that is easy and pleasant to view.

  5. Disparity modification in stereoscopic images for emotional enhancement

    NASA Astrophysics Data System (ADS)

    Kawai, Takashi; Atsuta, Daiki; Kim, Sanghyun; Häkkinen, Jukka

    2015-03-01

    This paper describes an experiment 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 prominent 3D movies. From the results of the experiment, it was found that pleasant and arousal was increased by expanding 3D space to a certain level. In addition, pleasant gradually decreased and arousal gradually increased by expansion of 3D space above a certain level.

  6. 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.

  7. Stereoscopic high-speed imaging using additive colors

    NASA Astrophysics Data System (ADS)

    Sankin, Georgy N.; Piech, David; Zhong, Pei

    2012-04-01

    An experimental system for digital stereoscopic imaging produced by using a high-speed color camera is described. Two bright-field image projections of a three-dimensional object are captured utilizing additive-color backlighting (blue and red). The two images are simultaneously combined on a two-dimensional image sensor using a set of dichromatic mirrors, and stored for off-line separation of each projection. This method has been demonstrated in analyzing cavitation bubble dynamics near boundaries. This technique may be useful for flow visualization and in machine vision applications.

  8. 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)

  9. 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.

  10. The compatibility of consumer DLP projectors with time-sequential stereoscopic 3D visualisation

    NASA Astrophysics Data System (ADS)

    Woods, Andrew J.; Rourke, Tegan

    2007-02-01

    A range of advertised "Stereo-Ready" DLP projectors are now available in the market which allow high-quality flickerfree stereoscopic 3D visualization using the time-sequential stereoscopic display method. The ability to use a single projector for stereoscopic viewing offers a range of advantages, including extremely good stereoscopic alignment, and in some cases, portability. It has also recently become known that some consumer DLP projectors can be used for timesequential stereoscopic visualization, however it was not well understood which projectors are compatible and incompatible, what display modes (frequency and resolution) are compatible, and what stereoscopic display quality attributes are important. We conducted a study to test a wide range of projectors for stereoscopic compatibility. This paper reports on the testing of 45 consumer DLP projectors of widely different specifications (brand, resolution, brightness, etc). The projectors were tested for stereoscopic compatibility with various video formats (PAL, NTSC, 480P, 576P, and various VGA resolutions) and video input connections (composite, SVideo, component, and VGA). Fifteen projectors were found to work well at up to 85Hz stereo in VGA mode. Twenty three projectors would work at 60Hz stereo in VGA mode.

  11. Removing the cardboard effect in stereoscopic images using smoothed depth maps

    NASA Astrophysics Data System (ADS)

    Shimono, Koichi; Tam, Wa James; Vázquez, Carlos; Speranza, Filippo; Renaud, Ron

    2010-02-01

    Depth maps are important for generating images with new camera viewpoints from a single source image for stereoscopic applications. In this study we examined the usefulness of smoothing depth maps for reducing the cardboard effect that is sometimes observed in stereoscopic images with objects appearing flat like cardboard pieces. Six stereoscopic image pairs, manifesting different degrees of the cardboard effect, were tested. Depth maps for each scene were synthesized from the original left-eye images and then smoothed (low-pass filtered). The smoothed depth maps and the original left-eye images were then used to render new views to create new "processed" stereoscopic image pairs. Subjects were asked to assess the cardboard effect of the original stereoscopic images and the processed stereoscopic images on a continuous quality scale, using the doublestimulus method. In separate sessions, depth quality and visual comfort were also assessed. The results from 16 viewers indicated that the processed stereoscopic image pairs tended to exhibit a reduced cardboard effect, compared to the original stereoscopic image pairs. Although visual comfort was not compromised with the smoothing of the depth maps, depth quality was significantly reduced when compared to the original.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. Three-dimensional elliptical reconstruction for stereoscopic magnetic resonance angiography.

    PubMed

    Liao, Jan-Ray; Kuo, Shye-Chorng

    2012-06-01

    Stereoscopic MRA acquires a pair of blood vessel projections at two different viewing angles. Previously, we have developed two algorithms to reconstruct 3-D blood vessels from stereoscopic MRA. The assumption we made was that blood vessels were tilting circular tubes and the shape of the vessel on every cross-section was an ellipse. Since an ellipse can be represented in either algebraic form or parametric form, our previous algorithms reconstructed the ellipses by representing them in these two forms. In this paper, we further improved the accuracy of our previous algorithms by an order through two enhancements. The first improvement we made was a better method to estimate the rotation angle of the major axis of an ellipse. Instead of using the center of two adjacent ellipses to estimate the rotation angle as in our previous method, the new method used the projection lengths of the two views to estimate the angle. The second improvement we made was the equation to describe the relationship between the major/minor axes and the projection lengths. In our experiments, the average estimation error for the parametric algorithm was improved from 0.471 pixels to 0.066 pixels. The average error for the algebraic algorithm was improved from 0.101 pixels to 0.014 pixels. PMID:21899986

  19. 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

  20. 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.

  1. 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.

  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. Exocentric judgements in real environments and stereoscopic displays

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Tharp, Gregory K.; Grunwald, Arthur J.; Smith, Stephen

    1991-01-01

    Spatial direction errors during interpretation of perspective images, such as 3D map displays, may originate from misjudgment of the orientation of the viewing direction used to make the display. One source of these errors could be perceptual evidence of the display surface. Two experiments are reported in which the same judgment exocentric task was presented, but the cues to the picture surface were reduced or eliminated by presenting the task as a stereoscopic, virtual image or by a geometrically matched physical model. A theory developed to model exocentric direction errors on perspective displays has been fitted to the data from these two experiments. The parameters estimated from the fit in both experiments indicate that the subjects may be more correctly estimating the viewing direction than in ordinary perspective displays. Consequently, in some real world or stereo viewing conditions, errors in estimating the viewing direction are not likely to dominate exocentric direction errors.

  4. Head-coupled remote stereoscopic camera system for telepresence applications

    NASA Technical Reports Server (NTRS)

    Bolas, M. T.; Fisher, S. S.

    1990-01-01

    The Virtual Environment Workstation Project (VIEW) at NASA's Ames Research Center has developed a remotely controlled stereoscopic camera system that can be used for telepresence research and as a tool to develop and evaluate configurations for head-coupled visual systems associated with space station telerobots and remore manipulation robotic arms. The prototype camera system consists of two lightweight CCD video cameras mounted on a computer controlled platform that provides real-time pan, tilt, and roll control of the camera system in coordination with head position transmitted from the user. This paper provides an overall system description focused on the design and implementation of the camera and platform hardware configuration and the development of control software. Results of preliminary performance evaluations are reported with emphasis on engineering and mechanical design issues and discussion of related psychophysiological effects and objectives.

  5. 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.

  6. 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.

  7. Stereoscopic particle image velocimetry in a transonic turbine stage

    NASA Astrophysics Data System (ADS)

    Lang, H.; Mørck, T.; Woisetschläger, J.

    2002-06-01

    In order to investigate the flow field in axial turbine stages, a continuously operating transonic test turbine facility for high pressure ratios was designed at Graz University of Technology, Austria. This test facility allows optical access to the rotor and to the stator trailing edge. The three-dimensional velocity distribution in the region of stator-rotor interaction was investigated by stereoscopic particle image velocimetry. To obtain the three-dimensional velocity vectors in one plane at the mid-section of the turbine blades, a calibration-based method was used. Light-sheet delivery, seeding and triggering to four pre-defined rotor-stator positions are discussed, and an insight into the rotor-stator interaction is given, including vortex shedding in the stator wake.

  8. 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

  9. 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.

  10. 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

  11. 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…

  12. Instant Photography and Learning: The Polaroid Education Project.

    ERIC Educational Resources Information Center

    Nash, Paul

    1982-01-01

    Describes the effects of elementary curriculum materials using instant photography developed for the Polaroid Education Project. The materials most effectively reached students who do not respond to verbal materials. Students and teachers shared authority in interpreting student photographs. Photography activities increased parent interest and…

  13. 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…

  14. From a Distance: Robust Reference Service via Instant Messaging

    ERIC Educational Resources Information Center

    Meulemans, Yvonne Nalani; Carr, Allison; Ly, Pearl

    2010-01-01

    Reference service via instant messaging (IM) has significant potential to benefit distance learners. There has been wide experimentation with IM to expand reference services in libraries across the US, with mixed results. Concern has been expressed that IM cannot provide the same reference experience as face-to-face interactions. One academic…

  15. 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.

  16. 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…

  17. Instant Messaging Reference in an Academic Library: A Case Study.

    ERIC Educational Resources Information Center

    Foley, Marianne

    2002-01-01

    During the 2000-2001 academic year, the General Libraries of the University at Buffalo conducted a pilot project to assess feasibility of providing reference through instant messaging. Describes the project, its implementation, the software used, staffing issues, and publicity efforts. Discusses results of the project in terms of user…

  18. 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.

  19. 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.

  20. New stereo shooting evaluation metric based on stereoscopic distortion and subjective perception

    NASA Astrophysics Data System (ADS)

    Yang, Jiachen; Gao, Zhiqun; Chu, Rongrong; Liu, Yun; Lin, Yancong

    2015-06-01

    In this paper, we examined the stereoscopic distortion by varying image acquisition parameters including but not limited to inter-camera distance, camera focal length, and shooting distance. Since a lot of new elements or problems about stereoscopic perception have not been considered or precisely defined before, an advanced shooting principle is raised in this paper to guarantee the overall quality of stereoscopic images. In this paper, based on stereoscopic distortion and features of camera configurations, we present new shooting formulae for both toed-in and parallel camera configurations. Besides, a new shooting evaluation metric is proposed for the evaluation of stereo camera quality. The experimental results show that the proposed approach can precisely assess the visual perception quality of stereo images according to the shooting parameters and can effectively evaluate the quality of stereo camera.

  1. High-Speed Generation of Illumination Spectra for a Stereoscopic Endoscope

    NASA Technical Reports Server (NTRS)

    Fritz, Eric

    2011-01-01

    Traditional stereoscopic vision (3D) is achieved through use of two separate cameras, arranged to emulate human eyes. This method works well on most projects, but becomes impractical on small scale designs, such as surgical endoscopes. This project is focused on developing a stereoscopic endoscope, using a single camera and Conjugated Multiple?Bandpass Filters (CMBF) to produce stereoscopic vision. Each half of filter is built to allow a distinct spectrum to pass through, while blocking the complimentary spectrum. A system with complimentary filters can produce stereoscopic images. To accomplish this, the light must be filtered at the source to match the filters at the camera. Additionally, the light source and camera must be synchronized in a way that each image will show only one filter spectrum. In this paper, I will describe the design and characterization of the prototype electro?optical system, including optical throughput measurements and video produced using this method.

  2. A stereoscopic movie player with real-time content adaptation to the display geometry

    NASA Astrophysics Data System (ADS)

    Duch"ne, Sylvain; Lambers, Martin; Devernay, Frédéric

    2012-03-01

    3D shape perception in a stereoscopic movie depends on several depth cues, including stereopsis. For a given content, the depth perceived from stereopsis highly depends on the camera setup as well as on the display size and distance. This can lead to disturbing depth distortions such as the cardboard effect or the puppet theater effect. As more and more stereoscopic 3D content is produced in 3D (feature movies, documentaries, sports broadcasts), a key point is to get the same 3D experience on any display. For this purpose, perceived depth distortions can be resolved by performing view synthesis. We propose a real time implementation of a stereoscopic player based on the open-source software Bino, which is able to adapt a stereoscopic movie to any display, based on user-provided camera and display parameters.

  3. 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.

  4. 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.

  5. 3 CFR - Improving Availability of Relevant Executive Branch Records to the National Instant Criminal...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Records to the National Instant Criminal Background Check System Presidential Documents Other Presidential... National Instant Criminal Background Check System Memorandum for the Heads of Executive Departments and Agencies Since it became operational in 1998, the National Instant Criminal Background Check System...

  6. 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. PMID:25620087

  7. 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

  8. 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.

  9. 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

  10. Eliciting steady-state visual evoked potentials by means of stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Calore, Enrico; Gadia, Davide; Marini, Daniele

    2014-03-01

    Brain-Computer Interfaces (BCIs) provide users communication and control capabilities by analyzing their brain activity. A technique to implement BCIs, used recently also in Virtual Reality (VR) environments, is based on the Steady State Visual Evoked Potentials (SSVEPs) detection. Exploiting the SSVEP response, BCIs could be implemented showing targets flickering at different frequencies and detecting which is gazed by the observer analyzing her/his electroencephalographic (EEG) signals. In this work, we evaluate the use of stereoscopic displays for the presentation of SSVEP eliciting stimuli, comparing their effectiveness between monoscopic and stereoscopic stimuli. Moreover we propose a novel method to elicit SSVEP responses exploiting the stereoscopic displays capability of presenting dichoptic stimuli. We have created an experimental scene to present flickering stimuli on an active stereoscopic display, obtaining reliable control of the targets' frequency independently for the two stereo views. Using an EEG acquisition device, we analyzed the SSVEP responses from a group of subjects. From the preliminary results, we got evidence that stereoscopic displays represent valid devices for the presentation of SSVEP stimuli. Moreover, the use of different flickering frequencies for the two views of a single stimulus proved to elicit non-linear interactions between the stimulation frequencies, clearly visible in the EEG signal. This suggests interesting applications for SSVEP-based BCIs in VR environments able to overcome some limitations imposed by the refresh frequency of standard displays, but also the use of commodity stereoscopic displays to implement binocular rivalry experiments.

  11. 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. PMID:26480428

  12. 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.

  13. Effect of camera separation on the viewing experience of stereoscopic photographs

    NASA Astrophysics Data System (ADS)

    Kytö, Mikko; Hakala, Jussi; Oittinen, Pirkko; Häkkinen, Jukka

    2012-01-01

    This study presents a geometric and subjective analysis of typical mobile stereoscopic 3-D images. The geometry of the stereoscopic pipeline from the scene to the eyes of the viewer is a highly relevant issue in stereoscopic media. One important factor is camera separation, because it can be used to control the perceived depth of stereoscopic images. The geometric analysis included consideration of disparity and roundness factor within typical mobile stereoscopic imaging scenes. These geometric properties of stereoscopic 3-D images were compared to subjective evaluations by varying camera separation in different scenes. The participants in this study evaluated the strength and naturalness of depth sensation and the overall viewing experience from still images with the single-stimulus method. The results showed that participants were able to perceive the change of depth range even though the images were shown in random order without a reference depth scale. The highest naturalness of depth sensation and viewing experience were achieved with 2 cm to 6 cm camera separation in every content. With these preferred camera separations, the disparity range was less than +/-1 deg and cardboard effect (quantified with roundness factor) did not negatively affect the naturalness of depth sensation.

  14. 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 %. PMID:24515118

  15. 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,…

  16. 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

  17. 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.

  18. 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

  19. Measurement of compressed breast thickness by optical stereoscopic photogrammetry

    SciTech Connect

    Tyson, Albert H.; Mawdsley, Gordon E.; Yaffe, Martin J.

    2009-02-15

    The determination of volumetric breast density (VBD) from mammograms requires accurate knowledge of the thickness of the compressed breast. In attempting to accurately determine VBD from images obtained on conventional mammography systems, the authors found that the thickness reported by a number of mammography systems in the field varied by as much as 15 mm when compressing the same breast or phantom. In order to evaluate the behavior of mammographic compression systems and to be able to predict the thickness at different locations in the breast on patients, they have developed a method for measuring the local thickness of the breast at all points of contact with the compression paddle using optical stereoscopic photogrammetry. On both flat (solid) and compressible phantoms, the measurements were accurate to better than 1 mm with a precision of 0.2 mm. In a pilot study, this method was used to measure thickness on 108 volunteers who were undergoing mammography examination. This measurement tool will allow us to characterize paddle surface deformations, deflections and calibration offsets for mammographic units.

  20. 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.

  1. Toward a stereoscopic encoder/decoder for digital cinema

    NASA Astrophysics Data System (ADS)

    Bensalma, Rafik; Larabi, Mohamed-Chaker

    2008-02-01

    The digital cinema is very challenging because it represents tomorrow way of capturing, post-producing and projecting movies. Specifications on this media are provided by DCI (Digital Cinema Initiatives) founded by the Hollywood Majors. Among the specifications we can find issues about resolution, bitrate, JPEG2000 compression Moreover, the market assumes that 3D could raise the turnover of cinema industry. The problem with is the availability of 2 streams (left and right) that double the amount of data and need adapted devices to decode and project movies. Cinema industry, represented by the stereoscopic group in SMPTE has expressed the need of having a unique master that combines two streams in one. This paper focuses on the study of the generation of a master with one of the streams and the embedment of the redundant information as metadata in JPEG2000 code-stream or MXF. The idea is to use the reference image in addition to some metadata to reconstruct the target image. The metadata represent the residual image and the contours description. Quality of reconstructed images depends on the compression ratio of the residual image. The obtained results are encouraging and the choice between JPEG2000 metadata embedding and MXF metadata still to be done.

  2. Comparison of operation efficiency for the insert task when using stereoscopic images with additional lines, stereoscopic images, and a manipulator with force feedback

    NASA Astrophysics Data System (ADS)

    Matsunaga, Katsuya; Shidoji, Kazunori; Matsubara, Kenjiro

    1999-05-01

    It has been reported that operation efficiency for the teleoperations using stereoscopic video images is lower than when using the naked eye in real environments. Here, the authors tried to improve the human-machine interface of this particular system to achieve higher operation efficiency for stereoscopic video imags by adding other information. An experiment was carried out under the four following conditions: when the insert task was performed by subjects using conventional stereoscopic video imags, when the centering lines of the cylindrical objects and holes were added to the conventional stereoscopic video images, when the force feedback was provided to the system manipulator as one object touched another object, and when both of the additional centering lines and force feedback were provided. The subject's task was to inset a cylindrical object into a round hole. The completion time was measured from the time of the starting signal to the time when the object was inserted into the hole. Completion time, when additional lines were given, was shorter than when the force feedback was provided, and when no additional information was provided. It was concluded that additional visual information contributed more to the recognition of the space rather than providing additional information about surface phenomena.

  3. 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

  4. STEREOSCOPIC POLAR PLUME RECONSTRUCTIONS FROM STEREO/SECCHI IMAGES

    SciTech Connect

    Feng, L.; Inhester, B.; Solanki, S. K.; Wilhelm, K.; Wiegelmann, T.; Podlipnik, B.; Howard, R. A.; Plunkett, S. P.; Wuelser, J. P.; Gan, W. Q.

    2009-07-20

    We present stereoscopic reconstructions of the location and inclination of polar plumes of two data sets based on the two simultaneously recorded images taken by the EUVI telescopes in the SECCHI instrument package onboard the Solar TErrestrial RElations Observatory spacecraft. The 10 plumes investigated show a superradial expansion in the coronal hole in three dimensions (3D) which is consistent with the two-dimensional results. Their deviations from the local meridian planes are rather small with an average of 6.{sup 0}47. By comparing the reconstructed plumes with a dipole field with its axis along the solar rotation axis, it is found that plumes are inclined more horizontally than the dipole field. The lower the latitude is, the larger is the deviation from the dipole field. The relationship between plumes and bright points has been investigated and they are not always associated. For the first data set, based on the 3D height of plumes and the electron density derived from SUMER/SOHO Si VIII line pair, we found that electron densities along the plumes decrease with height above the solar surface. The temperature obtained from the density scale height is 1.6-1.8 times larger than the temperature obtained from Mg IX line ratios. We attribute this discrepancy to a deviation of the electron and the ion temperatures. Finally, we have found that the outflow speeds studied in the O VI line in the plumes corrected by the angle between the line of sight and the plume orientation are quite small with a maximum of 10 km s{sup -1}. It is unlikely that plumes are a dominant contributor to the fast solar wind.

  5. 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

  6. Rejuvenating Hydrator: Restoring Epidermal Hyaluronic Acid Homeostasis With Instant Benefits.

    PubMed

    Narurkar, Vic A; Fabi, Sabrina G; Bucay, Vivian W; Tedaldi, Ruth; Downie, Jeanine B; Zeichner, Joshua A; Butterwick, Kimberly; Taub, Amy; Kadoya, Kuniko; Makino, Elizabeth T; Mehta, Rahul C; Vega, Virginia L

    2016-01-01

    Skin aging is a combination of multifactorial mechanisms that are not fully understood. Intrinsic and extrinsic factors modulate skin aging, activating distinctive processes that share similar molecular pathways. One of the main characteristics of youthful skin is its large capacity to retain water, and this decreases significantly as we age. A key molecule involved in maintaining skin hydration is hyaluronic acid (HA). Concentration of HA in the skin is determined by the complex balance between its synthesis, deposition, association with cellular structures, and degradation. HA bio-equivalency and bio-compatibility have been fundamental in keeping this macromolecule as the favorite of the skincare industry for decades. Scientific evidence now shows that topically applied HA is unable to penetrate the skin and is rapidly degraded on the skin surface. SkinMedica's HA5 Rejuvenating Hydrator (SkinMedica Inc., an Allergan company, Irvine, CA) promotes restoration of endogenous epidermal HA homeostasis and provides instant smoothing and hydration of the skin. These dual benefits are accomplished through the combination of 2 breakthrough technologies: 1) a unique blend of actives powered by SkinMedica proprietary flower-derived stem cell extract that restores the endogenous production of HA; and 2) a proprietary mix of 5 HA forms that plump the skin, decreasing the appearance of fine lines/wrinkles. Pre-clinical studies demonstrated that HA5 induces expression of key epidermal differentiation and barrier markers as well as epidermal HA synthases. A decrease expression of hyaluronidases was also observed upon HA5 application. Initial clinical studies showed that within 15 minutes of application, HA5 instantly improves the appearance of fine lines/wrinkles and skin hydration. Subjects that continue using HA5 (for 8 weeks) demonstrated significant improvements in fine lines/wrinkles, tactile roughness, and skin hydration. In summary, the blend of these 2 key technologies

  7. Evaluating visual discomfort in stereoscopic projection-based CAVE system with a close viewing distance

    NASA Astrophysics Data System (ADS)

    Song, Weitao; Weng, Dongdong; Feng, Dan; Li, Yuqian; Liu, Yue; Wang, Yongtian

    2015-05-01

    As one of popular immersive Virtual Reality (VR) systems, stereoscopic cave automatic virtual environment (CAVE) system is typically consisted of 4 to 6 3m-by-3m sides of a room made of rear-projected screens. While many endeavors have been made to reduce the size of the projection-based CAVE system, the issue of asthenopia caused by lengthy exposure to stereoscopic images in such CAVE with a close viewing distance was seldom tangled. In this paper, we propose a light-weighted approach which utilizes a convex eyepiece to reduce visual discomfort induced by stereoscopic vision. An empirical experiment was conducted to examine the feasibility of convex eyepiece in a large depth of field (DOF) at close viewing distance both objectively and subjectively. The result shows the positive effects of convex eyepiece on the relief of eyestrain.

  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. Design of stereoscopic viewing system based on a compact mirror and dual monitor

    NASA Astrophysics Data System (ADS)

    Wu, Hsien-Huang P.; Chang, Shih-Hsin

    2010-02-01

    Stereoscopic technologies continue to accelerate the adoption of 3-D in both professional and consumer applications. Stereo 3-D displays have the potential to benefit geospatial intelligence, complex visualization, pharmaceutical development, petroleum exploration, medicine, entertainment, architecture, simulation, and other difficult tasks. A single-mirror dual monitor stereoscope system that can offer the full resolution of the current LCD display for 3-D viewing is proposed. This new approach utilizes an isosceles trapezoid mirror and two monitors to provide a cost-effective approach for stereoscopic viewing. Mathematical formulas for the design of the compact mirror were derived based on a novel scheme, and an implementation of the system was conducted to verify the practicability of the proposed method. We believe its compactness, low cost, and high image quality can become a very competitive choice among various display techniques currently available.

  10. 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

  11. [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

  12. Adaptive instant record signals applied to detection with time reversal operator decomposition.

    PubMed

    Folegot, Thomas; de Rosny, Julien; Prada, Claire; Fink, Mathias

    2005-06-01

    Time reversal arrays are becoming common tools whether for detection or tomography. These applications require the measurement of the response from the array to one or several receivers. The most natural way to record the impulse responses for several sources is to generate pulses successively from each emitting point and record simultaneously the signals from the receivers. However, this method is very time consuming or inefficient in terms of signal-to-noise ratio. To overcome this limitation quasi-orthogonal pseudonoise signals like Kasami sequences can be used. For guided wave propagation, a very high degree of orthogonality between the signal is necessary to allow an accurate measure of the whole multipath structure of the transfer function. Hence, in this work, we propose a new family of pseudo-orthogonal signals that is adapted to the environment and more specifically, to highly dispersive media. These adaptive instant records signals are used experimentally to detect targets using the time reversal operator decomposition method. The accuracy of the 15 x 15 transfer functions acquired simultaneously, and therefore the detection capability, are demonstrated in an experimental ultrasonic waveguide as a small-scale model of shallow water propagation including bottom absorption and reverberation. PMID:16018479

  13. 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

  14. Instant well-log inversion with a parallel computer

    SciTech Connect

    Kimminau, S.J.; Trivedi, H.

    1993-08-01

    Well-log analysis requires several vectors of input data to be inverted with a physical model that produces more vectors of output data. The problem is inherently suited to either vectorization or parallelization. PLATO (parallel log analysis, timely output) is a research prototype system that uses a parallel architecture computer with memory-mapped graphics to invert vector data and display the result rapidly. By combining this high-performance computing and display system with a graphical user interface, the analyst can interact with the system in real time'' and can visualize the result of changing parameters on up to 1,000 levels of computed volumes and reconstructed logs. It is expected that such instant'' inversion will remove the main disadvantages frequently cited for simultaneous analysis methods, namely difficulty in assessing sensitivity to different parameters and slow output response. Although the prototype system uses highly specific features of a parallel processor, a subsequent version has been implemented on a conventional (Serial) workstation with less performance but adequate functionality to preserve the apparently instant response. PLATO demonstrates the feasibility of petroleum computing applications combining an intuitive graphical interface, high-performance computing of physical models, and real-time output graphics.

  15. Non-invasive instant genotyping of fluorescently labelled transgenic mice.

    PubMed

    Fink, Dieter; Yau, Tien Yin; Kolbe, Thomas; Rülicke, Thomas

    2015-01-01

    Fluorescence proteins have been useful as genetic reporters for a wide range of applications in biomedical research and are frequently used for the analysis of transgene activity. Here, we show that expression levels of the ubiquitously expressed fluorescent proteins eGFP, mCherry, and tdTomato can be measured in transgenic mouse lines with random or targeted integrations. We identified the tail of the mouse as the tissue best suited for quantifying fluorescence intensity and show that expression levels in the tail correlate with gene dose. This allows for instant non-invasive determination of the genetic condition at the transgenic locus (hemizygous/heterozygous and homozygous), while simultaneously providing an objective comparison for transgene expression levels among different mouse lines. In summary, we demonstrate for the first time that the gene dose of a ubiquitously expressed fluorescence reporter can be reliably quantified and directly linked to the genotype of transgenic mice. Based on this information, animals with the appropriate genotype can be instantly selected without laborious analysis for establishing and breeding of new transgenic lines, reducing the number of "waste" animals. Furthermore, no tissue sampling is necessary, which is a significant refinement of genotyping procedures. Both aspects are important improvements for the genotyping of transgenic mice that follow the principles of the 3 Rs (reduction and refinement). PMID:25981046

  16. 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

  17. 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.

  18. 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…

  19. 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…

  20. 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.

  1. 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 ...

  2. Stereoscopic Anatomy: Evaluation of a New Teaching System in Human Gross Anatomy

    ERIC Educational Resources Information Center

    Prentice, Ernest D.; And Others

    1977-01-01

    A stereoscopic slide-based autoinstructional program has been developed as a substitute for dissection in teaching gross anatomy. Evaluation data suggest that this program, while having minor limitations in terms of anatomical orientation, does provide a viable alternative to dissection. (Editor/LBH)

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Reheating the D-brane universe via instant preheating

    SciTech Connect

    Panda, Sudhakar; Sami, M.; Thongkool, I.

    2010-05-15

    We investigate a possibility of reheating in a scenario of D-brane inflation in a warped deformed conifold background which includes perturbative corrections to throat geometry sourced by a chiral operator of dimension 3/2 in the conformal field theory. The effective D-brane potential, in this case, belongs to the class of nonoscillatory models of inflation for which the conventional reheating mechanism does not work. We find that gravitational particle production is inefficient and leads to reheating temperature of the order of 10{sup 8} GeV. We show that instant preheating is quite suitable to the present scenario and can easily reheat the universe to a temperature which is higher by about 3 orders of magnitude than its counterpart associated with gravitational particle production. The reheating temperature is shown to be insensitive to a particular choice of inflationary parameters suitable to observations.

  12. Instant Casting Movie Theater: The Future Cast System

    NASA Astrophysics Data System (ADS)

    Maejima, Akinobu; Wemler, Shuhei; Machida, Tamotsu; Takebayashi, Masao; Morishima, Shigeo

    We have developed a visual entertainment system called “Future Cast” which enables anyone to easily participate in a pre-recorded or pre-created film as an instant CG movie star. This system provides audiences with the amazing opportunity to join the cast of a movie in real-time. The Future Cast System can automatically perform all the processes required to make this possible, from capturing participants' facial characteristics to rendering them into the movie. Our system can also be applied to any movie created using the same production process. We conducted our first experimental trial demonstration of the Future Cast System at the Mitsui-Toshiba pavilion at the 2005 World Exposition in Aichi Japan.

  13. 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.

  14. 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.

  15. 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…

  16. 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.

  17. Fast Times and Digital Literacy: Participation Roles and Portfolio Construction within Instant Messaging

    ERIC Educational Resources Information Center

    Jacobs, Gloria E.

    2006-01-01

    The purpose of this study was to develop an understanding of adolescent use of instant messaging. Grounded in the New Literacy Studies stance that literacy is a social practice embedded in local contexts and informed by global ideologies (Street, 1995), I argue that participation in digital literacies such as instant messaging has implications for…

  18. Using Instant Feedback System and Micro Exams to Enhance Active Learning

    ERIC Educational Resources Information Center

    Sabag, N.; Kosolapov, S.

    2012-01-01

    This paper presents the outcomes of the preliminary survey in which the method of IFS was used to integrate motivating questions into the lecture presentations in order to increase the students' involvement. Instant Feedback System (IFS) enables the educators to improve their own teaching by getting instant and real-time feedback about how clear…

  19. 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.

  20. 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

  1. No-reference stereoscopic image quality measurement based on generalized local ternary patterns of binocular energy response

    NASA Astrophysics Data System (ADS)

    Zhou, Wujie; Yu, Lu

    2015-09-01

    Perceptual no-reference (NR) quality measurement of stereoscopic images has become a challenging issue in three-dimensional (3D) imaging fields. In this article, we propose an efficient binocular quality-aware features extraction scheme, namely generalized local ternary patterns (GLTP) of binocular energy response, for general-purpose NR stereoscopic image quality measurement (SIQM). More specifically, we first construct the binocular energy response of a distorted stereoscopic image with different stimuli of amplitude and phase shifts. Then, the binocular quality-aware features are generated from the GLTP of the binocular energy response. Finally, these features are mapped to the subjective quality score of the distorted stereoscopic image by using support vector regression. Experiments on two publicly available 3D databases confirm the effectiveness of the proposed metric compared with the state-of-the-art full reference and NR metrics.

  2. 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.

  3. 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.

  4. [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

  5. 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.

  6. 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.

  7. 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

  8. 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. PMID:22818394

  9. 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

  10. A new concept of stereoscopic imaging system using single optical channel and a deflector: pilot study

    NASA Astrophysics Data System (ADS)

    Jang, Won Hyuk; Kang, Heesung; Son, Taeyoon; Park, Jihoon; Jun, Eunkwon; Jung, Byungjo

    2014-03-01

    An imaging system was developed based on single-channel and transparent rotating deflector (TRD) to achieve stereoscopic video imaging. To acquire images at high frame rate, a CMOS camera was used with triggering function allowing image acquisition at certain time point. Stepping motor was controlled to rotate in an arc, stopping at the edge for image acquisition. The acquired 2D images were displayed in stereoscopic 3D using active shutter glasses and conventional display monitor. Using microcontroller (MCU) as centralized control system, system components were controlled and synchronized through using general purpose input/output (GPIO) ports. The created system was evaluated for two factors: motor rotation analysis based on MCU signal generation; and image property based on coefficient of variation calculation.

  11. 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.

  12. A perceptual quality metric for high-definition stereoscopic 3D video

    NASA Astrophysics Data System (ADS)

    Battisti, F.; Carli, M.; Stramacci, A.; Boev, A.; Gotchev, A.

    2015-03-01

    The use of 3D video is growing in several fields such as entertainment, military simulations, medical applications. However, the process of recording, transmitting, and processing 3D video is prone to errors thus producing artifacts that may affect the perceived quality. Nowadays a challenging task is the definition of a new metric able to predict the perceived quality with low computational complexity in order to be used in real-time applications. The research in this field is very active due to the complexity of the analysis of the influence of stereoscopic cues. In this paper we present a novel stereoscopic metric based on the combination of relevant features able to predict the subjective quality rating in a more accurate way.

  13. 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.

  14. 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

  15. Real-time arbitrary view synthesis method for ultra-HD auto-stereoscopic display

    NASA Astrophysics Data System (ADS)

    Cai, Yuanfa; Sang, Xinzhu; Duo, Chen; Zhao, Tianqi; Fan, Xin; Guo, Nan; Yu, Xunbo; Yan, Binbin

    2013-08-01

    An arbitrary view synthesis method from 2D-Plus-Depth image for real-time auto-stereoscopic display is presented. Traditional methods use depth image based rendering (DIBR) technology, which is a process of synthesizing "virtual" views of a scene from still or moving images and associated per-pixel depth information. All the virtual view images are generated and then the ultimate stereo-image is synthesized. DIBR can greatly decrease the number of reference images and is flexible and efficient as the depth images are used. However it causes some problems such as the appearance of holes in the rendered image, and the occurrence of depth discontinuity on the surface of the object at virtual image plane. Here, reversed disparity shift pixel rendering is used to generate the stereo-image directly, and the target image won't generate holes. To avoid duplication of calculation and also to be able to match with any specific three-dimensional display, a selecting table is designed to pick up appropriate virtual viewpoints for auto-stereoscopic display. According to the selecting table, only sub-pixels of the appropriate virtual viewpoints are calculated, so calculation amount is independent of the number of virtual viewpoints. In addition, 3D image warping technology is used to translate depth information to parallax between virtual viewpoints and parallax, and the viewer can adjust the zero-parallax-setting-plane (ZPS) and change parallax conveniently to suit his/her personal preferences. The proposed method is implemented with OPENGL and demonstrated on a laptop computer with a 2.3 GHz Intel Core i5 CPU and NVIDA GeForce GT540m GPU. We got a frame rate 30 frames per second with 4096×2340 video. High synthesis efficiency and good stereoscopic sense can be obtained. The presented method can meet the requirements of real-time ultra-HD super multi-view auto-stereoscopic display.

  16. What every surgeon wants: practical aspects on the use of stereoscopic applications in operative theatres

    NASA Astrophysics Data System (ADS)

    Ilgner, Justus; Biedron, Slavomir; Westhofen, Martin

    2010-02-01

    Introduction: Many operative specialties rely on the use of microscopes and endoscopes for visualizing operative fields in minimally invasive or microsurgical interventions. Conventional optical devices present relevant details only to the surgeon or one assisting professional. Advances in information technology have propagated stereoscopic visual information to all operative theatre personnel in real time, which, in turn, adds to the load of complex technical devices to be handled and maintained in operative theatres. Material and methods: In the last six years, we have been using conventional (SD, 720 x 576 pixels) and high definition (1280 x 720 pixels) stereoscopic video cameras attached to conventional operative microscopes either in parallel to direct visualization of the operative field or as all-digital processing of the operative image for the surgeon including all other staff. Aspects included the type of display used, image quality, time delay due to image processing, visual comfort, time consumption in set-up, ease of use as well as robustness of the system. Results: General acceptance of stereoscopic display technology is high as all staff members are able to share the same visual information. The use of stereo cameras in parallel to direct visualization or as only visualization device mostly depended on image quality and personal preference of the surgeon. Predominant general factors are robustness, ease of use and additional time consumption imposed by setup and handling. Visual comfort was noted as moderately important as there was wide variability between staff members. Type of display used and post-processing issues were regarded less important. Time delay induced by the video chain was negligible. Conclusion: The additional information given by stereoscopic video processing in real time outweighs the extra effort for handling and maintenance. However, further integration with existing technology and with the general workflow enhances acceptance

  17. An investigation of pointing postures in a 3D stereoscopic environment.

    PubMed

    Lin, Chiuhsiang Joe; Ho, Sui-Hua; Chen, Yan-Jyun

    2015-05-01

    Many object pointing and selecting techniques for large screens have been proposed in the literature. There is a lack of quantitative evidence suggesting proper pointing postures for interacting with stereoscopic targets in immersive virtual environments. The objective of this study was to explore users' performances and experiences of using different postures while interacting with 3D targets remotely in an immersive stereoscopic environment. Two postures, hand-directed and gaze-directed pointing methods, were compared in order to investigate the postural influences. Two stereo parallaxes, negative and positive parallaxes, were compared for exploring how target depth variances would impact users' performances and experiences. Fifteen participants were recruited to perform two interactive tasks, tapping and tracking tasks, to simulate interaction behaviors in the stereoscopic environment. Hand-directed pointing is suggested for both tapping and tracking tasks due to its significantly better overall performance, less muscle fatigue, and better usability. However, a gaze-directed posture is probably a better alternative than hand-directed pointing for tasks with high accuracy requirements in home-in phases. Additionally, it is easier for users to interact with targets with negative parallax than with targets with positive parallax. Based on the findings of this research, future applications involving different pointing techniques should consider both pointing performances and postural effects as a result of pointing task precision requirements and potential postural fatigue. PMID:25683543

  18. Toward a 3D video format for auto-stereoscopic displays

    NASA Astrophysics Data System (ADS)

    Vetro, Anthony; Yea, Sehoon; Smolic, Aljoscha

    2008-08-01

    There has been increased momentum recently in the production of 3D content for cinema applications; for the most part, this has been limited to stereo content. There are also a variety of display technologies on the market that support 3DTV, each offering a different viewing experience and having different input requirements. More specifically, stereoscopic displays support stereo content and require glasses, while auto-stereoscopic displays avoid the need for glasses by rendering view-dependent stereo pairs for a multitude of viewing angles. To realize high quality auto-stereoscopic displays, multiple views of the video must either be provided as input to the display, or these views must be created locally at the display. The former approach has difficulties in that the production environment is typically limited to stereo, and transmission bandwidth for a large number of views is not likely to be available. This paper discusses an emerging 3D data format that enables the latter approach to be realized. A new framework for efficiently representing a 3D scene and enabling the reconstruction of an arbitrarily large number of views prior to rendering is introduced. Several design challenges are also highlighted through experimental results.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Implementation of real-time 3D image communication system using stereoscopic imaging and display scheme

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Chul; Kim, Dong-Kyu; Ko, Jung-Hwan; Kim, Eun-Soo

    2004-11-01

    In this paper, a new stereoscopic 3D imaging communication system for real-time teleconferencing application is implemented by using IEEE 1394 digital cameras, Intel Xeon server computer system and Microsoft"s DirectShow programming library and its performance is analyzed in terms of image-grabbing frame rate. In the proposed system, two-view images are captured by using two digital cameras and processed in the Intel Xeon server computer system. And then, disparity data is extracted from them and transmitted to the client system with the left image through an information network and in the recipient two-view images are reconstructed and displayed on the stereoscopic 3D display system. The program for controlling the overall system is developed using the Microsoft DirectShow SDK. From some experimental results, it is found that the proposed system can display stereoscopic images in real-time with a full-color of 16 bits and a frame rate of 15fps.

  4. 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

  5. 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.

  6. 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.

  7. Subjective quality and depth assessment in stereoscopic viewing of volume-rendered medical images

    NASA Astrophysics Data System (ADS)

    Rousson, Johanna; Couturou, Jeanne; Vetsuypens, Arnout; Platisa, Ljiljana; Kumcu, Asli; Kimpe, Tom; Philips, Wilfried

    2014-03-01

    No study to-date explored the relationship between perceived image quality (IQ) and perceived depth (DP) in stereoscopic medical images. However, this is crucial to design objective quality metrics suitable for stereoscopic medical images. This study examined this relationship using volume-rendered stereoscopic medical images for both dual- and single-view distortions. The reference image was modified to simulate common alterations occurring during the image acquisition stage or at the display side: added white Gaussian noise, Gaussian filtering, changes in luminance, brightness and contrast. We followed a double stimulus five-point quality scale methodology to conduct subjective tests with eight non-expert human observers. The results suggested that DP was very robust to luminance, contrast and brightness alterations and insensitive to noise distortions until standard deviation σ=20 and crosstalk rates of 7%. In contrast, IQ seemed sensitive to all distortions. Finally, for both DP and IQ, the Friedman test indicated that the quality scores for dual-view distortions were significantly worse than scores for single-view distortions for multiple blur levels and crosstalk impairments. No differences were found for most levels of brightness, contrast and noise distortions. So, DP and IQ didn't react equivalently to identical impairments, and both depended whether dual- or single-view distortions were applied.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. Fusion of stereoscopic video and laparoscopic ultrasound for minimally invasive partial nephrectomy

    NASA Astrophysics Data System (ADS)

    Cheung, Carling L.; Wedlake, Christopher; Moore, John; Pautler, Stephen E.; Ahmad, Anis; Peters, Terry M.

    2009-02-01

    The development of an augmented reality environment that combines laparoscopic video and ultrasound imaging for image-guided minimally invasive abdominal surgical procedures, such as partial nephrectomy and radical prostatectomy, is an ongoing project in our laboratory. Our system overlays magnetically tracked ultrasound images onto endoscopic video to create a more intuitive visualization for mapping lesions intraoperatively and to give the ultrasound image context in 3D space. By presenting data in a common environment, this system will allow surgeons to visualize the multimodality information without having to switch between different images. A stereoscopic laparoscope from Visionsense Limited enhances our current system by providing surgeons with additional visual information through improved depth perception. In this paper, we develop and validate a calibration method that determines the transformation between the images from the stereoscopic laparoscope and the 3D locations of structures represented by a tracked laparoscopic ultrasound probe. We first calibrate the laparoscope with a checkerboard pattern and measure how accurate the transformation from image space to tracking space is. We then perform a target localization task using our fused environment. Our initial experience has demonstrated an RMS registration accuracy in 3D of 2.21mm for the laparoscope and 1.16mm for the ultrasound in a working volume of 0.125m3, indicating that magnetically tracked stereoscopic laparoscope and ultrasound images may be appropriately combined using magnetic tracking as long as steps are taken to ensure that the magnetic field generated by the system is not distorted by surrounding objects close to the working volume.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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). PMID:15458136

  1. Changes in stereoscopic depth perception caused by decentration of spectacle lenses.

    PubMed

    Jiménez, J R; Rubiño, M; Díaz, J A; Hita, E; del Barco, L J

    2000-08-01

    The effect that decentered spectacle (ophthalmic) lenses exert on depth perception has been studied, evaluating stereopsis through the disparity range (maximum horizontal disparity) for random-dot stereograms (RDS). The results show that variations in fusional convergence due to increments of decentration can diminish the stereopsis in observers, reducing the region within which stereoscopic correspondence can take place. Decreases in disparity ranges were found for vertical and horizontal prismatic effects, although the prismatic effect necessary for this was less in the vertical case. A decreased disparity range has also been confirmed with figural-stimuli stereograms and using prisms for generating the prismatic effects. PMID:10966068

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

    PubMed

    Lopez, 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

  3. 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.

  4. 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. PMID:25075268

  5. 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

  6. 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

  7. Evaluation of stereoscopic video cameras synchronized with the movement of an operator's head on the teleoperation of the actual backhoe shovel

    NASA Astrophysics Data System (ADS)

    Minamoto, Masahiko; Matsunaga, Katsuya

    1999-05-01

    Operator performance while using a remote controlled backhoe shovel is described for three different stereoscopic viewing conditions: direct view, fixed stereoscopic cameras connected to a helmet mounted display (HMD), and rotating stereo camera connected and slaved to the head orientation of a free moving stereo HMD. Results showed that the head- slaved system provided the best performance.

  8. 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)

  9. 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.

  10. Using stereoscopic real-time graphics to shorten training time for complex mechanical tasks

    NASA Astrophysics Data System (ADS)

    Tecchia, Franco; Carrozzino, Marcello; Rossi, Fabio; Bergamasco, Massimo; Vescovi, Marco; Pisu, Francesca

    2006-02-01

    The present paper presents the hands-on results of the use of a large screen stereoscopic installation to train technicians on maintenance tasks of large machineries for a leading mechanical industry. Such machinery, deployed from the company in remote locations around the world, need complex and lengthy maintenance procedures, to be performed periodically by teams of highly trained technicians. The firm organize continuous training classes to a large number of its technicians, using qualified trainers and continuously updating machinery documentation, resulting in long and expensive periods of time of technicians inactivity. Classes involve training on assembly and disassembly operations of the company complex mechanical products and were traditionally based on the use of video documentation, 2D mechanical drawings and live demonstrations on real equipment. In an attempt to improve this process, the firm equipped some of the training centers with large stereoscopic projection facilities and dedicated software, introducing the use of real-time stereo rendering of CAD models for virtual disassembly/assembly sequences. The firm investigated then potential benefits of the new methodology compared to the traditional one. The present article presents an overview of the technological framework used, and outlines the results of such comparison performed over a period of 6 months.

  11. 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.

  12. Broadcast-quality-stereoscopic video in a time-critical entertainment and corporate environment

    NASA Astrophysics Data System (ADS)

    Gay, Jean-Philippe

    1995-03-01

    `reality present: Peter Gabrial and Cirque du Soleil' is a 12 minute original work directed and produced by Doug Brown, Jean-Philippe Gay & A. Coogan, which showcases creative content applications of commercial stereoscopic video equipment. For production, a complete equipment package including a Steadicam mount was used in support of the Ikegami LK-33 camera. Remote production units were fielded in the time critical, on-stage and off-stage environments of 2 major live concerts: Peter Gabriel's Secret World performance at the San Diego Sports Arena, and Cirque du Soleil's Saltimbanco performance in Chicago. Twin 60 Hz video channels were captured on Beta SP for maximum post production flexibility. Digital post production and field sequential mastering were effected in D-2 format at studio facilities in Los Angeles. The program was world premiered to a large public at the World of Music, Arts and Dance festivals in Los Angeles and San Francisco, in late 1993. It was presented to the artists in Los Angeles, Montreal and Washington D.C. Additional presentations have been made using a broad range of commercial and experimental stereoscopic video equipment, including projection systems, LCD and passive eyewear, and digital signal processors. Technical packages for live presentation have been fielded on site and off, through to the present.

  13. Depth separation in ten observers with a new stereoscopic X-ray acquisition system.

    PubMed

    Moll, T; Turjman, F; Picard, C; Bres, J P; Amiel, M

    1997-01-01

    The aim of this work was to assess the depth separation of a new X-ray digital stereo angiographic system through visualization on a stereoscopic monitor. Before starting the clinical trial of this new stereo-digital angiographic system, it seemed to us mandatory to assess the inherent performance of the system to depict depth information, as well as the ability of the users to work with it. With this idea we designed a global test based on the observation of a physical test object by the potential users of the system, during a session long enough to simulate an angiographic study. The acquisition system consisted of a twin focal-spot X-ray tube and a standard DSA DG 300 (General Electric/CGR). The stereo display was controlled by a liquid crystal modulator placed in front of a black-and-white monitor. Special polarized glasses worn by the observers allowed right- and left-image separation. Depth separation was measured in ten observers by means of a stereoscopic test object. Six of the ten observers were able to locate accurately three-dimensional patterns separated by a 12- to 1.5-mm gap. No learning effect was noticed. This result suggested that stereo display through wireless polarized glasses coupled to up-to-date digital subtraction angiography technology may provide an accurate and ergonomic way to a dimensional enhancement of X-ray angiography. PMID:9377527

  14. 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.

  15. Development of 3D mobile receiver for stereoscopic video and data service in T-DMB

    NASA Astrophysics Data System (ADS)

    Lee, Gwangsoon; Lee, Hyun; Yun, Kugjin; Hur, Namho; Lee, Soo In

    2011-02-01

    In this paper, we present a development of 3D-T DMB (three-dimensional digital multimedia broadcasting) receiver for providing 3D video and data service. First, for a 3D video service, the developed receiver is capable of decoding and playing 3D AV contents that is encoded by simulcast encoding method and that is transmitted via T-DMB network. Second, the developed receiver can render stereoscopic multimedia objects delivered using MPEG-4 BIFS technology that is also employed in T-DMB. Specially, this paper introduces hardware and software architecture and its implementation of 3D T-DMB receiver. The developed 3D T-DMB receiver has capabilities of generating stereoscopic viewing on the glasses-free 3D mobile display, therefore we propose parameters for designing the 3D display, together with evaluating the viewing angle and distance through both computer simulation and actual measurement. Finally, the availability of 3D video and data service is verified using the experimental system including the implemented receiver and a variety of service examples.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Web-based intermediate view reconstruction for multiview stereoscopic 3D display

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Kyu; Lee, Won-Kyung; Ko, Jung-Hwan; Bae, Kyung-hoon; Kim, Eun-Soo

    2005-08-01

    In this paper, web-based intermediate view reconstruction for multiview stereoscopic 3D display system is proposed by using stereo cameras and disparity maps, Intel Xeon server computer system and Microsoft's DirectShow programming library and its performance is analyzed in terms of image-grabbing frame rate and number of views. In the proposed system, stereo images are initially captured by using stereo digital cameras and then, these are processed in the Intel Xeon server computer system. And then, the captured two-view image data is compressed by extraction of disparity data between them and transmitted to another client system through the information network, in which the received stereo data is displayed on the 16-view stereoscopic 3D display system by using intermediate view reconstruction. The program for controlling the overall system is developed based on the Microsoft DirectShow SDK. From some experimental results, it is found that the proposed system can display 16-view 3D images with a gray of 8bits and a frame rate of 15fps in real-time.

  1. Stereoscopic Visual Attention-Based Regional Bit Allocation Optimization for Multiview Video Coding

    NASA Astrophysics Data System (ADS)

    Zhang, Yun; Jiang, Gangyi; Yu, Mei; Chen, Ken; Dai, Qionghai

    2010-12-01

    We propose a Stereoscopic Visual Attention- (SVA-) based regional bit allocation optimization for Multiview Video Coding (MVC) by the exploiting visual redundancies from human perceptions. We propose a novel SVA model, where multiple perceptual stimuli including depth, motion, intensity, color, and orientation contrast are utilized, to simulate the visual attention mechanisms of human visual system with stereoscopic perception. Then, a semantic region-of-interest (ROI) is extracted based on the saliency maps of SVA. Both objective and subjective evaluations of extracted ROIs indicated that the proposed SVA model based on ROI extraction scheme outperforms the schemes only using spatial or/and temporal visual attention clues. Finally, by using the extracted SVA-based ROIs, a regional bit allocation optimization scheme is presented to allocate more bits on SVA-based ROIs for high image quality and fewer bits on background regions for efficient compression purpose. Experimental results on MVC show that the proposed regional bit allocation algorithm can achieve over [InlineEquation not available: see fulltext.]% bit-rate saving while maintaining the subjective image quality. Meanwhile, the image quality of ROIs is improved by [InlineEquation not available: see fulltext.] dB at the cost of insensitive image quality degradation of the background image.

  2. 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

  3. Subjective contrast sensitivity function assessment in stereoscopic viewing of Gabor patches

    NASA Astrophysics Data System (ADS)

    Rousson, Johanna; Haar, Jérémy; Platiša, Ljiljana; Piepers, Bastian; Kimpe, Tom R.; Philips, Wilfried

    2015-03-01

    While 3D displays are entering hospitals, no study to-date has explored the impact of binocular disparity and 3D inclination on contrast sensitivity function (CSF) of humans. However, knowledge of the CSF is crucial to properly calibrate medical, especially diagnostic, displays. This study examined the impact of two parameters on the CSF: (1) the depth plane position (0 mm or 171 mm behind the display plane, respectively DP:0 or DP:171), and (2) the 3D inclination (0° or 45° around the horizontal axis of the considered DP), each of these for seven spatial frequencies ranging from 0.4 to 10 cycles per degree (cpd). The stimuli were computer-generated stereoscopic images of a vertically oriented 2D Gabor patch with a given frequency. They were displayed on a 24" full HD stereoscopic display using a patterned retarder. Nine human observers assessed the CSF in a 3-down 1-up staircase experiment. Medians of the measured contrast sensitivities and results of Friedman tests suggest that the 2D CSF as modeled by Barten1 still holds when a 3D display is used as a 2D visualization system (DP:0). However, the 3D CSF measured at DP:171 was found different from the 2D CSF at frequencies below 1 cpd and above 10 cpd.

  4. Recalibration of a stereoscopic camera system for in-flight wing deformation measurements

    NASA Astrophysics Data System (ADS)

    Kirmse, Tania

    2016-05-01

    A decalibration of a stereoscopic camera system caused by slight movements of the cameras can influence the accuracy of the measured 3D positions significantly. Especially for large scale in-flight applications this is difficult to avoid, e.g. due to the high loads and the vibration level occurring during dynamic flight manoeuvres. Thus a practicable approach for a correction of the results by a recalibration of the camera system is necessary. The image pattern correlation technique (IPCT) delivers large area surface results which enables the assessment of its triangulation error in detail as a measure for the quality of the results. The objective of the presented recalibration is a minimisation of the overall triangulation error by a correction of the external camera parameters. The criteria to assess the reliability of the 3D-surface results and the deformation results derived from are described as well as the limitations of the method. A wing deformation measurement on a VUT100 Cobra aeroplane by means of stereoscopic IPCT was used as a test case to demonstrate the applicability of the recalibration method on real flight test data.

  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. 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

  7. 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.

  8. 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. PMID:8793223

  9. Figure and Ground in the Visual Cortex: V2 Combines Stereoscopic Cues with Gestalt Rules

    PubMed Central

    Qiu, Fangtu T.; von der Heydt, Rüdiger

    2006-01-01

    Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring three-dimensional (3D) layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border-ownership coding). Here we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (gestalt factors). These are combined in single neurons so that the ‘near’ side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays gestalt factors influence the responses and can enhance or null the stereoscopic depth information. PMID:15996555

  10. OBSERVATIONS OF THE BLAZAR 3C 66A WITH THE MAGIC TELESCOPES IN STEREOSCOPIC MODE

    SciTech Connect

    Aleksic, J.; Blanch, O.; Antonelli, L. A.; Bonnoli, G.; Antoranz, P.; Backes, M.; Barrio, J. A.; Bose, D.; Bastieri, D.; Gonzalez, J. Becerra; Berger, K.; Bednarek, W.; Berdyugin, A.; Bernardini, E.; Biland, A.; Boller, A.; Bock, R. K.; Tridon, D. Borla; Bordas, P.; Bosch-Ramon, V. E-mail: ksaito@mppmu.mpg.de

    2011-01-10

    We report new observations of the intermediate-frequency peaked BL Lacertae object 3C 66A with the MAGIC telescopes. The data sample we use were taken in 2009 December and 2010 January, and comprises 2.3 hr of good quality data in stereoscopic mode. In this period, we find a significant signal from the direction of the blazar 3C 66A. The new MAGIC stereoscopic system is shown to play an essential role for the separation between 3C 66A and the nearby radio galaxy 3C 66B, which is at a distance of only 6'. The derived integral flux above 100 GeV is 8.3% of the Crab Nebula flux and the energy spectrum is reproduced by a power law of photon index 3.64 {+-} 0.39{sub stat} {+-} 0.25{sub sys}. Within errors, this is compatible with the one derived by VERITAS in 2009. From the spectra corrected for absorption by the extragalactic background light, we only find small differences between the four models that we applied, and constrain the redshift of the blazar to z < 0.68.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Correlative tomography.

    PubMed

    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

  17. 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

  18. Stereoscopic Perception

    NASA Astrophysics Data System (ADS)

    Clapp, Robert E.

    1987-06-01

    There is only one real world, We "see" that world as extending into three dimensions because we look at it with two eyes. We are not presented with two "pictures" of the real world, but with two separate views. Views not pictures. The analog of the eye as a camera has done violence to the development of concepts of human vision. The eye is a dynamic sensing apparatus that supplies the brain with inputs from which the brain constructs the scene we "see", and so is responsible for our perceptual structuring of the real world. These visual perceptions are dependent upon our other sensory inputs as well. Indeed, our body senses control and direct, to some degree, where out eyes look and what we "see". This process of conceptualization is thoroughly egocentric. This paper addresses the processes by which our mind/eye/senses interact to form our perception (and concepts) of the world (real or illusionary) and the advantages (and problems) of our egocentric reduction of the data inputs.

  19. Quantitative Measurement of Eyestrain on 3D Stereoscopic Display Considering the Eye Foveation Model and Edge Information

    PubMed Central

    Heo, Hwan; Lee, Won Oh; Shin, Kwang Yong; Park, Kang Ryoung

    2014-01-01

    We propose a new method for measuring the degree of eyestrain on 3D stereoscopic displays using a glasses-type of eye tracking device. Our study is novel in the following four ways: first, the circular area where a user's gaze position exists is defined based on the calculated gaze position and gaze estimation error. Within this circular area, the position where edge strength is maximized can be detected, and we determine this position as the gaze position that has a higher probability of being the correct one. Based on this gaze point, the eye foveation model is defined. Second, we quantitatively evaluate the correlation between the degree of eyestrain and the causal factors of visual fatigue, such as the degree of change of stereoscopic disparity (CSD), stereoscopic disparity (SD), frame cancellation effect (FCE), and edge component (EC) of the 3D stereoscopic display using the eye foveation model. Third, by comparing the eyestrain in conventional 3D video and experimental 3D sample video, we analyze the characteristics of eyestrain according to various factors and types of 3D video. Fourth, by comparing the eyestrain with or without the compensation of eye saccades movement in 3D video, we analyze the characteristics of eyestrain according to the types of eye movements in 3D video. Experimental results show that the degree of CSD causes more eyestrain than other factors. PMID:24834910

  20. 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…

  1. Stereoscopic uncooled thermal imaging with autostereoscopic 3D flat-screen display in military driving enhancement systems

    NASA Astrophysics Data System (ADS)

    Haan, H.; Münzberg, M.; Schwarzkopf, U.; de la Barré, R.; Jurk, S.; Duckstein, B.

    2012-06-01

    Thermal cameras are widely used in driver vision enhancement systems. However, in pathless terrain, driving becomes challenging without having a stereoscopic perception. Stereoscopic imaging is a well-known technique already for a long time with understood physical and physiological parameters. Recently, a commercial hype has been observed, especially in display techniques. The commercial market is already flooded with systems based on goggle-aided 3D-viewing techniques. However, their use is limited for military applications since goggles are not accepted by military users for several reasons. The proposed uncooled thermal imaging stereoscopic camera with a geometrical resolution of 640x480 pixel perfectly fits to the autostereoscopic display with a 1280x768 pixels. An eye tracker detects the position of the observer's eyes and computes the pixel positions for the left and the right eye. The pixels of the flat panel are located directly behind a slanted lenticular screen and the computed thermal images are projected into the left and the right eye of the observer. This allows a stereoscopic perception of the thermal image without any viewing aids. The complete system including camera and display is ruggedized. The paper discusses the interface and performance requirements for the thermal imager as well as for the display.

  2. Real-world stereoscopic performance in multiple-focal-plane displays: How far apart should the image planes be?

    NASA Astrophysics Data System (ADS)

    Watt, Simon J.; MacKenzie, Kevin J.; Ryan, Louise

    2012-03-01

    Conventional stereoscopic displays present conflicting stimuli to vergence and accommodation, causing fatigue, discomfort, and poor stereo depth perception. One promising solution is 'depth filtering', in which continuous variations in focal distance are simulated by distributing image intensity across multiple focal planes. The required image-plane spacing is a critical parameter, because there are constraints on the total number that can be used. Depth-filtered images have been shown to support continuous and reasonably accurate accommodation responses with 1.1 dioptre (D) image-plane spacings. However, retinal contrast is increasingly attenuated with increasing image-plane separation. Thus, while such stimuli may eliminate the vergence-accommodation conflict, they may also unacceptably degrade stereoscopic depth perception. Here we measured stereoacuity, and the time needed for stereoscopic fusion, for real targets and depth-filtered approximations to the same stimuli (image-plane spacings of 0.6, 0.9 and 1.2 D). Stereo fusion time was reasonably consistent across conditions. Stereoacuity for depth-filtered stimuli was only slightly poorer than for real targets with 0.6 D image-plane separation, but deteriorated rapidly thereafter. Our results suggest that stereoscopic depth perception, not accommodation and vergence responses, is the limiting factor in determining acceptable image-plane spacing for depth-filtered images. We suggest that image-plane spacing should ideally not exceed ~0.6 D.

  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. 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…

  5. 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…

  6. 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)…

  7. 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

  8. 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…

  9. 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…

  10. 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…

  11. 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)

  12. 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…

  13. 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

  14. 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…

  15. 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…

  16. [Effect of addition of instant corn flour on rheological characteristics of wheat flour and breadmaking III].

    PubMed

    Martínez, F; el-Dahs, A A

    1993-12-01

    The instant corn flour prepared by the hydrothermal process using corn grits soaked in water at room temperature (28-30 degrees C) for 5 hours and steaming for 1 minute at 118 degrees C presented characteristics similar to that of flours prepared with grits soaked in water at temperature higher than room temperature and different steaming time (5 and 15 minutes). The addition of instant corn flour up of a 25% mixture with wheat flour reduced the peak of maximum viscosity during the heating cycle; however, the final viscosity during the cooling cycle was increased. The water absorption was increased with the increase of substitution in the level of wheat flour. Extensibility, maximum resistance and values of area were reduced with an increase in the level of instant corn flour in the mixture. However, extension resistance and proportional number were increased. Bread prepared from a mixture of instant corn flour and wheat flour showed higher weight with low loaf volume, color and texture of the crumb related to bread wheat. PMID:7872835

  17. 76 FR 69287 - National Instant Criminal Background Check System Section Agency Information Collection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Federal Bureau of Investigation National Instant Criminal Background Check System Section Agency... in accordance with Title 5, Code of Federal Regulations (CFR), Sec. 1320.10. If you have...

  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. Socialization in the "Virtual Hallway": Instant Messaging in the Asynchronous Web-Based Distance Education Classroom.

    ERIC Educational Resources Information Center

    Nicholson, Scott

    2002-01-01

    Examined differences in communication between masters degree students at Syracuse University who used instant messaging (IM) services and those who did not in the same asynchronous distance education Web-based course. Results showed that students who used IM found it easier to communicate and felt a stronger sense of community. (Author/LRW)

  20. Instant Video Revisiting for Reflection: Extending the Learning of Children and Teachers.

    ERIC Educational Resources Information Center

    Hong, Seong B.; Broderick, Jane T.

    This article discusses how instant video revisiting (IVR) promotes reflective thinking for both teachers and children. IVR was used as a daily classroom experience with both the children and the teachers throughout one semester in two preschool classrooms with children 2.5 to 5 years old. The teachers used a digital video camera to generate data…

  1. Exploring the Use of Text and Instant Messaging in Higher Education Classrooms

    ERIC Educational Resources Information Center

    Lauricella, Sharon; Kay, Robin

    2013-01-01

    This article examined how higher education students used text and instant messaging for academic purposes with their peers and faculty. Specifically, comfort level, frequency of use, usefulness, reasons for messaging and differences between peer-to-peer and peer-to-instructor interactions were examined. Students noted that they were very…

  2. 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

  3. 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.

  4. Perceptual grouping via binocular disparity: The impact of stereoscopic good continuation.

    PubMed

    Deas, Lesley M; Wilcox, Laurie M

    2015-08-01

    Stereoscopic contextual effects are widely reported but are generally discussed in terms of 2-D Gestalt grouping principles, e.g., good continuation or closure. We propose that there are disparity-based grouping operations that are separable from 2-D grouping and instead depend on the distribution of binocular disparity information. Two experiments assess the impact of perceptual grouping via good disparity continuation. First, perceived depth magnitude is reduced for a multidot contour with a smooth disparity gradient compared to the end points in isolation. This reduction is eliminated when disparity jitter is introduced to the intermediate dots. Second, observers showed more efficient visual search for the continuous contour versus the discontinuous version. Therefore, when there is spatial support for interpretation of a slanted object, quantitative depth is reduced, but is rapidly detected in visual search. These results reflect the operation of disparity-based grouping, extending the 2-D principle of good continuation into the third dimension. PMID:26275212

  5. Time-resolved stereoscopic PIV study of flashback in swirl flames at elevated pressures

    NASA Astrophysics Data System (ADS)

    Ranjan, Rakesh; Ebi, Dominik; Clemens, Noel

    2015-11-01

    Boundary layer flashback of turbulent premixed swirl flames can pose a major challenge to the operation of stationary gas turbines, especially with hydrogen-rich fuels. To improve our understanding of the physics behind this phenomenon at gas turbine relevant conditions, it is essential to investigate flashback at elevated pressures. With this purpose in mind, flashback experiments with hydrogen/methane-air premixtures are conducted in a model swirl combustor installed in an optically accessible high-pressure combustion facility. We have employed stereoscopic PIV in conjunction with high speed chemiluminiscence imaging to study the upstream propagation of the flame in the premix tube during flashback. Experiments are run at pressures ranging from 1 atm to 5 atm. These time-resolved measurements provide valuable insight into the flame-flow interaction during flashback at elevated pressures.

  6. 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.

  7. Full-reference quality assessment of stereoscopic images by learning sparse monocular and binocular features

    NASA Astrophysics Data System (ADS)

    Li, Kemeng; Shao, Feng; Jiang, Gangyi; Yu, Mei

    2014-11-01

    Perceptual stereoscopic image quality assessment (SIQA) aims to use computational models to measure the image quality in consistent with human visual perception. In this research, we try to simulate monocular and binocular visual perception, and proposed a monocular-binocular feature fidelity (MBFF) induced index for SIQA. To be more specific, in the training stage, we learn monocular and binocular dictionaries from the training database, so that the latent response properties can be represented as a set of basis vectors. In the quality estimation stage, we compute monocular feature fidelity (MFF) and binocular feature fidelity (BFF) indexes based on the estimated sparse coefficient vectors, and compute global energy response similarity (GERS) index by considering energy changes. The final quality score is obtained by incorporating them together. Experimental results on four public 3D image quality assessment databases demonstrate that in comparison with the most related existing methods, the devised algorithm achieves high consistency alignment with subjective assessment.

  8. In-cylinder engine flow measurement using stereoscopic molecular tagging velocimetry (SMTV)

    NASA Astrophysics Data System (ADS)

    Mittal, M.; Sadr, R.; Schock, H. J.; Fedewa, A.; Naqwi, A.

    2009-02-01

    The stereoscopic molecular tagging velocimetry (SMTV) technique is used to obtain the multiple point measurement of an instantaneous three-component velocity field inside the cylinder of an internal combustion (IC) engine assembly. A novel image processing technique is implemented to obtain the velocity data. The technique has the advantage that it eliminates the geometric details required to obtain the three components of the velocity field. The procedure involves two major steps: (i) calibration process and (ii) data acquisition and reduction. Cycle-to-cycle variations of the three-component velocity field and out-of-plane vorticity are presented inside an engine cylinder. Preliminary results show that cycle-to-cycle variations are more prominent in the velocity component perpendicular to the tumble plane, as opposed to the in-plane components. Such new insights will help better understand the details of these flows and further improve CFD models for IC engines.

  9. Imaging SPR combined with stereoscopic 3D tracking to study barnacle cyprid-surface interactions

    NASA Astrophysics Data System (ADS)

    Maleshlijski, S.; Sendra, G. H.; Aldred, N.; Clare, A. S.; Liedberg, B.; Grunze, M.; Ederth, T.; Rosenhahn, A.

    2016-01-01

    Barnacle larvae (cyprids) explore surfaces to identify suitable settlement sites. This process is selective, and cyprids respond to numerous surface cues. To better understand the settlement process, it is desirable to simultaneously monitor both the surface exploration behavior and any close interactions with the surface. Stereoscopic 3D tracking of the cyprids provides quantitative access to surface exploration and pre-settlement rituals. Imaging surface plasmon resonance (SPR) reveals any interactions with the surfaces, such as surface inspection during bipedal walking and deposition of temporary adhesives. We report on a combination of both techniques to bring together information on swimming behavior in the vicinity of the interface and physical interactions of the cyprid with the surface. The technical requirements are described, and we applied the setup to cyprids of Balanus amphitrite. Initial data shows the applicability of the combined instrument to correlate exploration and touchdown events on surfaces with different chemical termination.

  10. 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.

  11. Freespace estimation in an autonomous wheelchair using a stereoscopic camera system.

    PubMed

    Nguyen, Thanh H; Vo, Kiet T

    2010-01-01

    This paper is concerned with the estimation of the height and width of freespace based on a Bayesian Recursive (BR) algorithm for an autonomous wheelchair using a stereoscopic camera system for disabled people. A 2D distance map for the purpose of freespace estimation is converted from a 3D point map using geometric projection and computation. The comparison of this 2D map to a 2D map obtained from Laser is carried out. Moreover, freespaces in the 2D map are estimated using a BR algorithm based on uncertainty information and control data. Given the average probability, a possible movement decision is then made for the mobile wheelchair. Experimental results obtained in an indoor environment prove the effectiveness of this estimation algorithm. PMID:21095651

  12. Film patterned retarder for stereoscopic three-dimensional display using ink-jet printing method.

    PubMed

    Lim, Young Jin; Yu, Ji Hoon; Song, Ki Hoon; Lee, Myong-Hoon; Ren, Hongwen; Mun, Byung-June; Lee, Gi-Dong; Lee, Seung Hee

    2014-09-22

    We propose a film patterned retarder (FPR) for stereoscopic three-dimensional display with polarization glasses using ink-jet printing method. Conventional FPR process requires coating of photo-alignment and then UV exposure using wire-grid mask, which is very expensive and difficult. The proposed novel fabrication method utilizes a plastic substrate made of polyether sulfone and an alignment layer, poly (4, 4' - (9, 9 -fluorenyl) diphenylene cyclobutanyltetracarboximide) (9FDA/CBDA) in which the former and the latter aligns reactive mesogen along and perpendicular to the rubbing direction, respectively. The ink-jet printing of 9FDA/CBDA line by line allows fabricating the cost effective FPR which can be widely applied for 3D display applications. PMID:25321734

  13. 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.

  14. 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 | ...

  15. 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.

  16. [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

  17. 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.

  18. 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. PMID:18354133

  19. An analysis of un-dissolved powders of instant powdered soup by using ultrasonographic image

    NASA Astrophysics Data System (ADS)

    Kawaai, Yukinori; Kato, Kunihito; Yamamoto, Kazuhiko; Kasamatsu, Chinatsu

    2008-11-01

    Nowadays, there are many instant powdered soups around us. When we make instant powdered soup, sometimes we cannot dissolve powders perfectly. Food manufacturers want to improve this problem in order to make better products. Therefore, they have to measure the state and volume of un-dissolved powders. Earlier methods for analyzing removed the un-dissolved powders from the container, the state of the un-dissolved power was changed. Our research using ultrasonographic image can measure the state of un-dissolved powders with no change by taking cross sections of the soup. We then make 3D soup model from these cross sections of soup. Therefore we can observe the inside of soup that we do not have ever seen. We construct accurate 3D model. We can visualize the state and volume of un-dissolved powders with analyzing the 3D soup models.

  20. Multibody instantly centered moving Lagrangian observer schemes. I - Formulation. II - Application to vehicular simulations

    NASA Technical Reports Server (NTRS)

    Padovan, Joseph; Kazempour, Amir

    1989-01-01

    A finite element modeling method employing an instantly centered moving Lagrangian observer is proposed to solve multibody problems involving several rotating components, each with its own rotational history. The present technique allows the steady-state behavior of the problem simulation to be rendered stationary and time independent. In the second part, the method is extended to model the steady and transient response of ground-based automotive-type vehicular systems, including the modeling of vehicular obstruction rollover events.

  1. Implementation and integration of a counterbalanced CRT-based stereoscopic display for interactive viewpoint control in virtual environment applications

    NASA Technical Reports Server (NTRS)

    Mcdowall, I. E.; Bolas, M.; Pieper, S.; Fisher, S. S.; Humphries, J.

    1990-01-01

    The NASA-Ames Counterbalanced CRT-based Stereoscopic Viewer (CCSV), which is being used as a viewing device for biomechanical CAD environments, is uniquely suited for applications in which the user frequently moves between desk work and virtual environment viewing, or in which high resolution views of the virtual environment are required, or in which the viewing device must be shared among collaborators in a group setting. The CCSV hardware encompasses a dual-CRT-based stereoscopic viewer with wide-angle optics, a video electronics box, a dedicated microprocessor system monitoring joint angles in the linkage, and a host computer interpreting sensor values and running the application which renders the right and left views for reader CRTs.

  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. Relationship of dough thermomechanical properties with oil uptake, cooking and textural properties of instant fried noodles.

    PubMed

    Gulia, Neelam; Khatkar, B S

    2014-04-01

    Instant noodles were prepared from fifteen diverse wheat cultivars varying widely in their flour quality and dough rheology. Dough thermomechanical parameters obtained by Mixolab and flour analytical properties were correlated with the quality of instant noodles including oil uptake, cooking quality and textural attributes. The Mixolab parameters dough development time and dough stability showed significant positive correlation with cooking time, cooked weight, overall acceptability, hardness, springiness, cohesiveness and chewiness of noodles, while negatively correlated with oil uptake and cooking loss, therefore, exhibiting a marked positive effect on quality of instant noodles. Lower protein breakdown represented by C2 torque was also positively related with overall acceptability, hardness, springiness, cohesiveness and chewiness of noodles. Stickiness/adhesiveness of noodles was revealed to be mainly conferred by falling number values (R (2 )= 0.671) and damaged starch (R (2 )= 0.523) content of wheat flour samples. Flour samples with lesser values of protein content, sodium dodecyl sulphate sedimentation volume, thermal stability of proteins, dough stability and dough development time were found to be linked with poor noodle quality. Medium strong flours performed better in noodle making, while weaker flours demonstrated poor noodle quality. Dough rheology of good noodle making flours was characterized with higher dough development time, dough stability, C2, C3, C4 as well as C5 values. Noodles with higher overall acceptability showed a more continuous and uniform protein starch matrix in comparison to the poor counterparts. PMID:23744117

  4. Behavioral responses of two subterranean termite species (Isoptera: Rhinotermitidae) to instant freezing or chilling temperatures.

    PubMed

    Hu, Xing Ping; Song, Dunlun

    2007-12-01

    The behavioral responses to instant freezing or chilling temperatures and survivorship of the Formosan subterranean termite, Coptotermes formosanus Shiraki, and the Eastern subterranean termite, Reticulitermes flavipes (Kollar), were studied using a novel experimental design that closely simulated subterranean termites' natural in-ground environment. Both termite species responded to changes in temperature by exhibiting a downward mass movement from the cold to warmer area of constant temperature. However, the degrees of response were specific to the species and temperature regimen. Approximately 88 and 96% of R. flavipes escaped from instant 0 degrees C and chilling regimens (from 24 to 0 degrees C at a rate of 1 degrees C/h or 1 degrees C/12 h), respectively, compared with approximately 77 and 91% of C. formosanus. No significant difference was detected between the two cooling regimens in either termite species. Controls resulted in a relatively even distribution within test tubes in both termite species. The small portion of the termites that did not escape endured a cold coma at a 24-h 0 degrees C and had low mortality of 2.2 and <1% in R. flavipes and <5.2 and <3% in C. formosanus at instant and chilling regimens, respectively. This result may have implications for understanding group intelligence and decision making evolved by subterranean termites to survive temporary freezing cold. PMID:18284773

  5. The influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children.

    PubMed

    Gligorović, Milica; Vučinić, Vesna; Eškirović, 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 and polaroid glasses were used for the examination of stereoscopic vision, while Cover test and Hirschberg's pupils reflex test were used for the evaluation of strabismus. In the area of non-verbal abilities was evaluated visual discrimination, visuomotor integration, constructive praxia, visual memory, strategy formation, non-verbal reasoning and the representational dimension of drawings. Subtests of ACADIA test of developmental abilities were used for the evaluation of non-verbal abilities (Atkinson et al., 1972). Statistically significant relations between strabismus and constructive praxia (p=0.009), visual memory (p=0.037), strategy formation (0.040) and the quality of drawings were determined by the results analysis. According to our findings, children with divergent strabismus achieve the best results. Children with stereoscopic vision generally achieve better results in all the examined areas of non-verbal abilities, and statistically significant relations were determined in the areas of visuomotor coordination (0.002), constructive praxia (0.026) and non-verbal reasoning (0.015), which are directly connected to visuospatial abilities. Children with convergent strabismus achieve significantly lower results in the areas of constructive praxia, visual memory, strategy formation and representational dimension of drawings, and children with the lack of stereoscopic vision--in the areas of visuomotor integration, constructive praxia and non-verbal reasoning. PMID:21536409

  6. Applications of stereoscopic height computations from dual geosynchronous satellite data/joint NASA-Japan stereo project

    NASA Technical Reports Server (NTRS)

    Fujita, T. T.; Dodge, J. C.

    1982-01-01

    Stereoscopic heights of the top of an Oklahoma thunderstorm were computed, finding that high cloud tops are not always characterized by very cold IR temperature. The identical method was also applied to the computation of stereo heights based on GOES West and GMS stereo pairs obtained under the NASA-JAPAN cooperative program. It was found that stereo techniques are extremely useful in understanding the structure of thunderstorms in the United States, as well as that of hurricanes over the South Pacific.

  7. 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

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

    NASA Astrophysics Data System (ADS)

    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. Comparative performance of multiview stereoscopic and mammographic display modalities for breast lesion detection

    SciTech Connect

    Webb, Lincoln J.; Samei, Ehsan; Lo, Joseph Y.; Baker, Jay A.; Ghate, Sujata V.; Kim, Connie; Soo, Mary Scott; Walsh, Ruth

    2011-04-15

    Purpose: Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true lesion and the inability to derive volumetric information. It has been shown that stereomammography can overcome these deficiencies by showing that layers of normal tissue lay at different depths. If standard stereomammography (i.e., a single stereoscopic pair consisting of two projection images) can significantly improve lesion detection, how will multiview stereoscopy (MVS), where many projection images are used, compare to mammography? The aim of this study was to assess the relative performance of MVS compared to mammography for breast mass detection. Methods: The MVS image sets consisted of the 25 raw projection images acquired over an arc of approximately 45 deg. using a Siemens prototype breast tomosynthesis system. The mammograms were acquired using a commercial Siemens FFDM system. The raw data were taken from both of these systems for 27 cases and realistic simulated mass lesions were added to duplicates of the 27 images at the same local contrast. The images with lesions (27 mammography and 27 MVS) and the images without lesions (27 mammography and 27 MVS) were then postprocessed to provide comparable and representative image appearance across the two modalities. All 108 image sets were shown to five full-time breast imaging radiologists in random order on a state-of-the-art stereoscopic display. The observers were asked to give a confidence rating for each image (0 for lesion definitely not present, 100 for lesion definitely present). The ratings were then compiled and processed using ROC and variance analysis. Results: The mean AUC for the five observers was 0.614{+-}0.055 for mammography and 0.778{+-}0.052 for multiview stereoscopy. The difference of 0.164{+-}0.065 was statistically significant with a

  10. Geometric in-flight calibration of the stereoscopic line-CCD scanner MOMS-2P

    NASA Astrophysics Data System (ADS)

    Kornus, Wolfgang; Lehner, Manfred; Schroeder, Manfred

    This paper describes the geometric in-flight calibration of the Modular Optoelectronic Multispectral Scanner MOMS-2P, which has collected digital multispectral and threefold along-track stereoscopic imagery of the earth's surface from the PRIRODA module of the Russian space station MIR from October 1996 to August 1999. The goal is the verification and, if necessary, the update of the calibration data, which were estimated from the geometric laboratory calibration. The paper is subdivided into two parts, describing two different procedures of geometric in-flight calibration. The first method is based on DLR matching software and is restricted to nadir looking channels, which are read out simultaneously. From a high number of individual point matches between the images of the same area taken by the different CCD arrays, the most reliable ones are selected and used to calculate shifts with components in and across flight direction between the CCD arrays. These actual shifts are compared to the nominal shifts, derived from the results of the laboratory calibration, and parameters of the valid camera model are estimated from both data sets by least squares adjustment. A special case of band-to-band registration are the two optically combined CCD-arrays of the nadir high-resolution channel. They are read out simultaneously with a nominal 10 pixel overlap in stereoscopic imaging mode A. The DLR matching software is applied to calculate the displacement vector between the two CCD-arrays. The second method is based on combined photogrammetric bundle adjustment using an adapted functional model for the reconstruction of the interior orientation. It requires precise and reliable ground control information as well as navigation data of the navigation-package MOMS-NAV. Nine contiguous image scenes of MOMS-2P data-take T083C building an about 550-km-long strip over southern Germany and Austria taken in March 1997 were evaluated. From both procedures calibration data are

  11. 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.

  12. 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.

  13. 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.

  14. Instant noodle intake and dietary patterns are associated with distinct cardiometabolic risk factors in Korea.

    PubMed

    Shin, Hyun Joon; Cho, Eunyoung; Lee, Hae-Jeung; Fung, Teresa T; Rimm, Eric; Rosner, Bernard; Manson, JoAnn E; Wheelan, Kevin; Hu, Frank B

    2014-08-01

    The consumption of instant noodles is relatively high in Asian populations. It is unclear whether a higher intake of instant noodles is associated with cardiometabolic risk independent of overall dietary patterns. We therefore investigated the association using the Korean National Health and Nutrition Examination Survey IV 2007-2009, a nationally representative cross-sectional survey of the Korean population with a clustered, multistage, stratified, and rolling sampling design. A total of 10,711 adults (54.5% women) 19-64 y of age were analyzed, with adjustment for sampling design complexity. Diet was assessed by using a 63-item food-frequency questionnaire. We identified 2 major dietary patterns with the use of principal components analysis: the "traditional dietary pattern" (TP), rich in rice, fish, vegetables, fruit, and potatoes, and the "meat and fast-food pattern" (MP), with less rice intake but rich in meat, soda, fried food, and fast food including instant noodles. The highest MP quintile was associated with increased prevalence of abdominal obesity (OR: 1.41; 95% CI: 1.05, 1.90), LDL cholesterol ≥130 mg/dL (1.3 g/L) (OR: 1.57, 95% CI 1.26, 1.95), decreased prevalence of low HDL cholesterol (OR: 0.65; 95% CI: 0.53, 0.80), and high triglycerides [≥150 mg/dL (1.5 g/L); OR: 0.73; 95% CI: 0.57, 0.93]. The highest quintile for the TP was associated with decreased prevalence of elevated blood pressure (OR: 0.73; 95% CI: 0.59, 0.90) and marginally lower trends for abdominal obesity (OR: 0.76; 95% CI: 0.58, 0.98; P-trend = 0.06), but neither of the dietary patterns was associated with prevalence of metabolic syndrome. The consumption of instant noodles ≥2 times/wk was associated with a higher prevalence of metabolic syndrome (OR: 1.68; 95% CI: 1.10, 2.55) in women but not in men (OR: 0.93; 95% CI: 0.58, 1.49; P-interaction = 0.04). The 2 major dietary patterns were associated with distinct cardiometabolic risk factors. The consumption of instant noodles was

  15. Integrating multi-view transmission system into MPEG-21 stereoscopic and multi-view DIA (digital item adaptation)

    NASA Astrophysics Data System (ADS)

    Lee, Seungwon; Park, Ilkwon; Kim, Manbae; Byun, Hyeran

    2006-10-01

    As digital broadcasting technologies have been rapidly progressed, users' expectations for realistic and interactive broadcasting services also have been increased. As one of such services, 3D multi-view broadcasting has received much attention recently. In general, all the view sequences acquired at the server are transmitted to the client. Then, the user can select a part of views or all the views according to display capabilities. However, this kind of system requires high processing power of the server as well as the client, thus posing a difficulty in practical applications. To overcome this problem, a relatively simple method is to transmit only two view-sequences requested by the client in order to deliver a stereoscopic video. In this system, effective communication between the server and the client is one of important aspects. In this paper, we propose an efficient multi-view system that transmits two view-sequences and their depth maps according to user's request. The view selection process is integrated into MPEG-21 DIA (Digital Item Adaptation) so that our system is compatible to MPEG-21 multimedia framework. DIA is generally composed of resource adaptation and descriptor adaptation. It is one of merits that SVA (stereoscopic video adaptation) descriptors defined in DIA standard are used to deliver users' preferences and device capabilities. Furthermore, multi-view descriptions related to multi-view camera and system are newly introduced. The syntax of the descriptions and their elements is represented in XML (eXtensible Markup Language) schema. If the client requests an adapted descriptor (e.g., view numbers) to the server, then the server sends its associated view sequences. Finally, we present a method which can reduce user's visual discomfort that might occur while viewing stereoscopic video. This phenomenon happens when view changes as well as when a stereoscopic image produces excessive disparity caused by a large baseline between two cameras. To

  16. 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

  17. 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

  18. Measurement of mean rotation and strain-rate tensors by using stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Özcan, O.; Meyer, K. E.; Larsen, P. S.

    2005-10-01

    A technique is described for measuring the mean velocity gradient (rate-of-displacement) tensor by using a conventional stereoscopic particle image velocimetry (SPIV) system. Planar measurement of the mean vorticity vector, rate-of-rotation and rate-of-strain tensors and the production of turbulent kinetic energy can be accomplished. Parameters of the Q criterion and negative λ2 techniques used for vortex identification can be evaluated in the mean flow field. Experimental data obtained for a circular turbulent jet issuing normal to a crossflow in a low speed wind tunnel for a jet-to-crossflow velocity ratio of 3.3 are presented to show the applicability of the proposed technique. The results reveal the presence of a secondary counter-rotating vortex pair (SCVP) which is located within the jet core and has a sense of rotation opposite to that of the primary one (PCVP). Consistency of the measurements is verified by the agreement of data obtained in two perpendicular planes. Accuracy of the data is discussed and algebraic relations for some measurement uncertainties are presented.

  19. 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

  20. 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.

  1. Three-component velocity field measurements of propeller wake using a stereoscopic PIV technique

    NASA Astrophysics Data System (ADS)

    Lee, Sang Joon; Paik, Bu Geun; Yoon, Jong Hwan; Lee, Choung Mook

    A stereoscopic PIV (Particle Image Velocimetry) technique was used to measure the three-dimensional flow structure of the turbulent wake behind a marine propeller with five blades. The out-of-plane velocity component was determined using two CCD cameras with an angular displacement configuration. Four hundred instantaneous velocity fields were measured for each of four different blade phases, and ensemble averaged in order to find the spatial evolution of the propeller wake in the region from the trailing edge up to one propeller diameter (D) downstream. The influence of propeller loading conditions on the wake structure was also investigated by measuring the velocity fields at three advance ratios (J=0.59, 0.72 and 0.88). The phase-averaged velocity fields revealed that a viscous wake formed by the boundary layers developed along the blade surfaces. Tip vortices were generated periodically and the slipstream contracted in the near-wake region. The out-of-plane velocity component and strain rate had large values at the locations of the tip and trailing vortices. As the flow moved downstream, the turbulence intensity, the strength of the tip vortices, and the magnitude of the out-of-plane velocity component at trailing vortices all decreased due to effects such as viscous dissipation, turbulence diffusion, and blade-to-blade interaction.

  2. 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.

  3. Characterizing and reducing crosstalk in printed anaglyph stereoscopic 3D images

    NASA Astrophysics Data System (ADS)

    Woods, Andrew J.; Harris, Chris R.; Leggo, Dean B.; Rourke, Tegan M.

    2013-04-01

    The anaglyph three-dimensional (3D) method is a widely used technique for presenting stereoscopic 3D images. Its primary advantages are that it will work on any full-color display and only requires that the user view the anaglyph image using a pair of anaglyph 3D glasses with usually one lens tinted red and the other lens tinted cyan. A common image quality problem of anaglyph 3D images is high levels of crosstalk-the incomplete isolation of the left and right image channels such that each eye sees a "ghost" of the opposite perspective view. In printed anaglyph images, the crosstalk levels are often very high-much higher than when anaglyph images are presented on emissive displays. The sources of crosstalk in printed anaglyph images are described and a simulation model is developed that allows the amount of printed anaglyph crosstalk to be estimated based on the spectral characteristics of the light source, paper, ink set, and anaglyph glasses. The model is validated using a visual crosstalk ranking test, which indicates good agreement. The model is then used to consider scenarios for the reduction of crosstalk in printed anaglyph systems and finds a number of options that are likely to reduce crosstalk considerably.

  4. 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.

  5. 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.

  6. 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.

  7. A stereoscopic video conversion scheme based on spatio-temporal analysis of MPEG videos

    NASA Astrophysics Data System (ADS)

    Lin, Guo-Shiang; Huang, Hsiang-Yun; Chen, Wei-Chih; Yeh, Cheng-Ying; Liu, Kai-Che; Lie, Wen-Nung

    2012-12-01

    In this article, an automatic stereoscopic video conversion scheme which accepts MPEG-encoded videos as input is proposed. Our scheme is depth-based, relying on spatio-temporal analysis of the decoded video data to yield depth perception cues, such as temporal motion and spatial contrast, which reflect the relative depths between the foreground and the background areas. Our scheme is shot-adaptive, demanding that shot change detection and shot classification be performed for tuning of algorithm or parameters that are used for depth cue combination. The above-mentioned depth estimation is initially block-based, followed by a locally adaptive joint trilateral upsampling algorithm to reduce the computing load significantly. A recursive temporal filter is used to reduce the possible depth fluctuations (and also artifacts in the synthesized images) resulting from wrong depth estimations. The traditional Depth-Image-Based-Rendering algorithm is used to synthesize the left- and right-view frames for 3D display. Subjective tests show that videos converted by our scheme provide comparable perceived depth and visual quality with those converted from the depth data calculated by stereo vision techniques. Also, our scheme is shown to outperform the well-known TriDef software in terms of human's perceived 3D depth. Based on the implementation by using "OpenMP" parallel programming model, our scheme is capable of executing in real-time on a multi-core CPU platform.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Utility of stereoscopic displays for indirect-vision driving and robot teleoperation.

    PubMed

    Chen, Jessie Y C; Oden, Razia V N; Merritt, John O

    2014-01-01

    The effectiveness of an active shutter-glasses stereoscopic display (SD) and a passive polarised SD was evaluated in a live robot-teleoperation task and a simulated indirect-vision driving task in various terrains. Overall, participants completed their tasks significantly faster with the SDs in three-dimensional (3D) mode than with the SDs in the baseline 2D mode. They also navigated more accurately with the SDs in 3D mode. When the effectiveness of the two types of SDs was examined separately, results showed that the active shutter-glasses SD resulted in faster responses and task completion times than the passive polarised SD, though most of the differences failed to reach statistical significance. Perceived workload when interacting with the two SD systems did not differ significantly between the active versus passive display types or between the 3D and 2D modes of operation; however, participants reported more severe discomfort after interacting with the passive polarised SD. PMID:24308626

  16. 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.

  17. In-Cylinder IC Engine Velocity Measurements using Stereoscopic Molecular Tagging Velocimetry

    NASA Astrophysics Data System (ADS)

    Sadr, Reza; Mittal, Mayank; Schock, Harold

    2008-11-01

    In-Cylinder velocity field measurement is of great importance for research aimed at improvement in fuel efficiency and reduction of emissions in internal combustion (IC) engines. Application of more conventional fluid velocimetry techniques for IC measurements is, however, limited due to complex flow condition and mechanical set up in IC engines. Stereoscopic Molecular Tagging Velocimetry (SMTV) technique is used to obtain the multiple point measurement of an instantaneous three dimensional velocity field in an IC engine assembly. A novel image processing technique is implemented to obtain the velocity data. The new algorithm is computationally less expensive and eliminates the need for geometric details in earlier techniques to obtain the three-dimensional velocity components. Cycle-to-cycle variations of three dimensional velocity field and out-of-plane vorticity are presented inside the engine cylinder for three different crank angle degrees (CAD) of 90^o, 180^o, and 270^o. Preliminary results show high cycle-to-cycle variations in the out-of-plane velocity component but less variation is observed in the velocity component along the cylinder axis. The flow has fully three-dimensional unsteady behavior during the intake stroke; however the variations are less during the compression stroke.

  18. 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.

  19. 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.

  20. 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.

  1. Full-reference quality assessment of stereoscopic images by learning binocular receptive field properties.

    PubMed

    Shao, Feng; Li, Kemeng; Lin, Weisi; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

    2015-10-01

    Quality assessment of 3D images encounters more challenges than its 2D counterparts. Directly applying 2D image quality metrics is not the solution. In this paper, we propose a new full-reference quality assessment for stereoscopic images by learning binocular receptive field properties to be more in line with human visual perception. To be more specific, in the training phase, we learn a multiscale dictionary from the training database, so that the latent structure of images can be represented as a set of basis vectors. In the quality estimation phase, we compute sparse feature similarity index based on the estimated sparse coefficient vectors by considering their phase difference and amplitude difference, and compute global luminance similarity index by considering luminance changes. The final quality score is obtained by incorporating binocular combination based on sparse energy and sparse complexity. Experimental results on five public 3D image quality assessment databases demonstrate that in comparison with the most related existing methods, the devised algorithm achieves high consistency with subjective assessment. PMID:26011880

  2. 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.

  3. 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.

  4. 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.

  5. Instant replay.

    PubMed

    Rosenthal, David I

    2013-06-01

    With widespread adoption of electronic health records (EHRs) and electronic clinical documentation, health care organizations now have greater faculty to review clinical data and evaluate the efficacy of quality improvement efforts. Unfortunately, I believe there is a fundamental gap between actual health care delivery and what we document in the current EHR systems. This process of capturing the patient encounter, which I'll refer to as transcription, is prone to significant data loss due to inadequate methods of data capture, multiple points of view, and bias and subjectivity in the transcriptional process. Our current EHR, text-based clinical documentation systems are lossy abstractions - one sided accounts of what take place between patients and providers. Our clinical notes contain the breadcrumbs of relationships, conversations, physical exams, and procedures but often lack the ability to capture the form, the emotions, the images, the nonverbal communication, and the actual narrative of interactions between human beings. I believe that a video record, in conjunction with objective transcriptional services and other forms of data capture, may provide a closer approximation to the truth of health care delivery and may be a valuable tool for healthcare improvement. PMID:26249640

  6. Physico-chemical properties of instant ogbono (Irvingia gabonensis) mix powder.

    PubMed

    Bamidele, Oluwaseun P; Ojedokun, Omotayo S; Fasogbon, Beatrice M

    2015-07-01

    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

  7. 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

  8. 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

  9. [Preparation of histotopographic goiter sections and endometrium scrapes for relevant instant diagnosis].

    PubMed

    Gol'dburt, N N; Perchuk, B D; Mironova, E A; Markin, S S

    1989-01-01

    Histotopographic examinations of goiters and scrapes taken as a whole are valuable to the emergency pathomorphological diagnosis of thyroid and endometrial diseases essential particularly for the differentiation of adenomas and well differentiated carcinomas. The examination can be carried out only by treating fresh, non-fixed materials with a deeply cooling knife of the routine cold microtome (Model X). Harris' or Ballard's hematoxylins are best used as elective dyes. The whole instant diagnosis fully described in the paper lasts 8 to 12 minutes. PMID:2775000

  10. Instant-off potential and polarization decay techniques for evaluation of an immersed steel structure

    SciTech Connect

    Hock, V.F.; Van Blaricum, V.L.; Houtz, W.A.; Setliff, L.F.

    1994-12-31

    Several devices and techniques for evaluating the condition of a coated and cathodically protected steel lock gate were tested in the field. Polarization decay and polarization resistance (E log I) measurements were conducted on the gates to determine the feasibility of using these techniques for in situ evaluation of the coating condition. In addition, two commercially available devices for measuring instant-off potentials were used to evaluate the cathodic protection system. Potentials obtained using these instruments were compared with the readings obtained using a recording oscilloscope and a digital multimeter. Results will be presented and discussed.

  11. 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.

  12. 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 ...

  13. Stereoscopic 3D Visual Discomfort Prediction: A Dynamic Accommodation and Vergence Interaction Model.

    PubMed

    Oh, Heeseok; Lee, Sanghoon; Bovik, Alan Conrad

    2016-02-01

    The human visual system perceives 3D depth following sensing via its binocular optical system, a series of massively parallel processing units, and a feedback system that controls the mechanical dynamics of eye movements and the crystalline lens. The process of accommodation (focusing of the crystalline lens) and binocular vergence is controlled simultaneously and symbiotically via cross-coupled communication between the two critical depth computation modalities. The output responses of these two subsystems, which are induced by oculomotor control, are used in the computation of a clear and stable cyclopean 3D image from the input stimuli. These subsystems operate in smooth synchronicity when one is viewing the natural world; however, conflicting responses can occur when viewing stereoscopic 3D (S3D) content on fixed displays, causing physiological discomfort. If such occurrences could be predicted, then they might also be avoided (by modifying the acquisition process) or ameliorated (by changing the relative scene depth). Toward this end, we have developed a dynamic accommodation and vergence interaction (DAVI) model that successfully predicts visual discomfort on S3D images. The DAVI model is based on the phasic and reflex responses of the fast fusional vergence mechanism. Quantitative models of accommodation and vergence mismatches are used to conduct visual discomfort prediction. Other 3D perceptual elements are included in the proposed method, including sharpness limits imposed by the depth of focus and fusion limits implied by Panum's fusional area. The DAVI predictor is created by training a support vector machine on features derived from the proposed model and on recorded subjective assessment results. The experimental results are shown to produce accurate predictions of experienced visual discomfort. PMID:26672036

  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. PMID:25594573

  15. 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. PMID:21309798

  16. Mining remote-image repositories with application to Mars Rover stereoscopic image datasets

    NASA Astrophysics Data System (ADS)

    Willis, Andrew; Shadid, Waseem; Eppes, Martha C.

    2009-02-01

    As of December 2008, the two Mars rover spacecraft Spirit and Opportunity have collected more than 4 years worth of data from nine imaging instruments producing greater than 200k images which includes both raw image data from spacecraft instruments and images generated by post-processing algorithms developed by NASA's Multimission Image Processing Laboratory (MIPL). This paper describes a prototype software system that allows scientists to browse and data-mine the images produced from NASA's Mars Exploratory Rover (MER) missions with emphasis on the automatic detection of images containing rocks that are of interest for geological research. We highlight two aspects of our prototype system: (1) software design for mining remote data repositories, (2) a computationally efficient image search engine for detecting MER images that containing rocks. Datatype abstractions made at the software design level allow users to access and visualize the source data through a single simple-to-use interface when the underlying data may originate from a local or remote image repository. Data mining queries into the MER image data are specified over chronological intervals denoted (sols) as each interval is a solar day. As in other mining applications, an automatic detection and classification algorithm is used to compute a relevance score that represents how relevant a given recorded image is to the user-specified query. Query results are presented as list of records, sorted by their relevance score, which the user may then visualize and investigate to extract information of interest. Several standard image analysis tools are provided for investigation of 2D images (e.g., histogram equalization, edge detection, etc.) and, when available, stereoscopic data is integrated with the image data using multiple windows which show both the 2D image and 3D surface geometry. The combination of data mining and a high-quality visualization interface provides MER researchers unprecedented access

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Three-dimensional tracking of multiple skin-colored regions by a moving stereoscopic system

    NASA Astrophysics Data System (ADS)

    Argyros, Antonis A.; Lourakis, Manolis I. A.

    2004-01-01

    A system that performs three-dimensional (3D) tracking of multiple skin-colored regions (SCRs) in images acquired by a calibrated, possibly moving stereoscopic rig is described. The system consists of a collection of techniques that permit the modeling and detection of SCRs, the determination of their temporal association in monocular image sequences, the establishment of their correspondence between stereo images, and the extraction of their 3D positions in a world-centered coordinate system. The development of these techniques has been motivated by the need for robust, near-real-time tracking performance. SCRs are detected by use of a Bayesian classifier that is trained with the aid of a novel technique. More specifically, the classifier is bootstrapped with a small set of training data. Then, as new images are being processed, an iterative training procedure is employed to refine the classifier. Furthermore, a technique is proposed to enable the classifier to cope with changes in illumination. Tracking of SCRs in time as well as matching of SCRs in the images of the employed stereo rig is performed through computationally inexpensive and robust techniques. One of the main characteristics of the skin-colored region tracker (SCRT) instrument is its ability to report the 3D positions of SCRs in a world-centered coordinate system by employing a possibly moving stereo rig with independently verging CCD cameras. The system operates on images of dimensions 640 × 480 pixels at a rate of 13 Hz on a conventional Pentium 4 processor at 1.8 GHz. Representative experimental results from the application of the SCRT to image sequences are also provided.

  2. 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.

  3. 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.

  4. Bi-planar 2D-to-3D registration in Fourier domain for stereoscopic x-ray motion tracking

    NASA Astrophysics Data System (ADS)

    Zosso, Dominique; Le Callennec, Benoît; Bach Cuadra, Meritxell; Aminian, Kamiar; Jolles, Brigitte M.; Thiran, Jean-Philippe

    2008-03-01

    In this paper we present a new method to track bone movements in stereoscopic X-ray image series of the knee joint. The method is based on two different X-ray image sets: a rotational series of acquisitions of the still subject knee that allows the tomographic reconstruction of the three-dimensional volume (model), and a stereoscopic image series of orthogonal projections as the subject performs movements. Tracking the movements of bones throughout the stereoscopic image series means to determine, for each frame, the best pose of every moving element (bone) previously identified in the 3D reconstructed model. The quality of a pose is reflected in the similarity between its theoretical projections and the actual radiographs. We use direct Fourier reconstruction to approximate the three-dimensional volume of the knee joint. Then, to avoid the expensive computation of digitally rendered radiographs (DRR) for pose recovery, we develop a corollary to the 3-dimensional central-slice theorem and reformulate the tracking problem in the Fourier domain. Under the hypothesis of parallel X-ray beams, the heavy 2D-to-3D registration of projections in the signal domain is replaced by efficient slice-to-volume registration in the Fourier domain. Focusing on rotational movements, the translation-relevant phase information can be discarded and we only consider scalar Fourier amplitudes. The core of our motion tracking algorithm can be implemented as a classical frame-wise slice-to-volume registration task. Results on both synthetic and real images confirm the validity of our approach.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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. PMID:26140574

  11. 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. PMID:20813373

  12. Instant membrane resealing in nlrp3 inflammmasome activation of endothelial cells.

    PubMed

    Chen, Yang; Yuan, Ming; Xia, Min; Wang, Lei; Zhang, Yang; Li, Pin-Lan

    2016-01-01

    The present study explored the molecular mechanisms by which instant cell membrane resealing (CMR) controls the activation of NOD-like receptor pyrin domain containing 3 (Nlrp3) inflammasomes. Using wavelength-switching fluorescent microscopy with PI and fura-2 as indicators, we monitored instant CMR simultaneously with (Ca(2+))i in mouse microvascular endothelial cell (MVECs). LCWE or saponin wad found to produce membrane injury, which was resealed in a Ca(2+)-dependent manner, but abolished by FasL, a membrane raft (MR) clustering stimulator. Even in the presence of Ca(2+), FasL prolonged the CMR time as shown by an earlier onset of PI influx (48±12 sec vs. 17±3 min. of control). These effects of FasL were substantially blocked by an MR disruptor, methyl-beta-cyclodextrin (MCD). The failure of CMR upon FasL activated Nlrp3 inflammasomes, which was blocked by MCD, a membrane resealing compound, VA64 or siRNA of an MR-facilitating enzyme, acid sphingomyelinase. This inflammasome activation was due to increased lysosomal permeability and cathepsin B release. It is concluded that an MR-associated CMR protects ECs from Nlrp3 inflammasome activation induced by membrane injury. PMID:26709796

  13. 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. PMID:23941367

  14. 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

  15. Fermion Propagators Interpolating between the Instant and Front Forms of Relativistic Dynamics

    NASA Astrophysics Data System (ADS)

    Ma, Bailing; Ji, Chueng-Ryong

    2016-03-01

    The instant form and the front form of dynamics originally proposed by Dirac in 1949 can be linked by introducing an interpolating angle. In the present work, we discuss the fermion propagator interpolating between the Instant Form Dynamics (IFD) and the Light Front Dynamics (LFD). Using a simple example, which is the scattering of a scalar particle with a fermion, we trace the fates of the time-ordered fermion propagators as the form of the dynamics goes from the IFD to the LFD. With our interpolation method, we show that the two time-ordered propagators corresponding to the positive and negative energy contributions in IFD change to the on-shell and instantaneous contributions in LFD, respectively. We also present the interpolating helicity amplitudes for the scattering of photon and fermion, i.e. the Compton Scattering, as well as for the two-photon production process in the pair annihilation of fermion and anti-fermion. We discuss the whole landscape of each of these amplitudes and amplitude squares that show the frame dependence as well as the interpolating angle dependence.

  16. 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.

  17. A compact high-definition low-cost digital stereoscopic video camera for rapid robotic surgery development.

    PubMed

    Carlson, Jay; Kowalczuk, Jędrzej; Psota, Eric; Pérez, Lance C

    2012-01-01

    Robotic surgical platforms require vision feedback systems, which often consist of low-resolution, expensive, single-imager analog cameras. These systems are retooled for 3D display by simply doubling the cameras and outboard control units. Here, a fully-integrated digital stereoscopic video camera employing high-definition sensors and a class-compliant USB video interface is presented. This system can be used with low-cost PC hardware and consumer-level 3D displays for tele-medical surgical applications including military medical support, disaster relief, and space exploration. PMID:22356964

  18. 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.

  19. Determination of the optimum viewing distance for a multi-view auto-stereoscopic 3D display.

    PubMed

    Yoon, Ki-Hyuk; Ju, Heongkyu; Park, Inkyu; Kim, Sung-Kyu

    2014-09-22

    We present methodologies for determining the optimum viewing distance (OVD) for a multi-view auto-stereoscopic 3D display system with a parallax barrier. The OVD can be efficiently determined as the viewing distance where statistical deviation of centers of quasi-linear distributions of illuminance at central viewing zones is minimized using local areas of a display panel. This method can offer reduced computation time because it does not use the entire area of the display panel during a simulation, but still secures considerable accuracy. The method is verified in experiments, showing its applicability for efficient optical characterization. PMID:25321731

  20. 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

    Ahn, Dohyun; Seo, Youngnam; Kim, Minkyung; Kwon, Joung Huem; Jung, Younbo; Ahn, Jungsun; Lee, Doohwang

    2014-07-01

    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

  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. 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

  3. Effects of the consumption of caffeinated and decaffeinated instant coffee beverages on oxidative stress induced by strenuous exercise in rats.

    PubMed

    Viana, André Luiz Machado; Fonseca, Miriam das Dores Mendes; Meireles, Elisson Lamin Jerônimo; Duarte, Stella Maris da Silveira; Rodrigues, Maria Rita; Paula, Fernanda Borges de Araujo

    2012-03-01

    Many authors attribute the antioxidant activity of brewed coffee to its caffeine content. In addition, caffeine intake has been associated with increased performance during physical exercise. This study analyzed the in vivo effects of drinking caffeinated and decaffeinated instant coffee (8%, w/v) on oxidative stress and antioxidant enzyme activity in the anterior tibialis muscles of rats subjected to intense exercise. It was observed that exercise induced lipid peroxidation (estimated using malondialdehyde) and protein oxidation (evaluated by determining the formation of carbonyl groups) in the muscle (P < 0.05). Decaffeinated instant coffee and caffeine solution did not exhibit antioxidant activity in vivo. Caffeinated instant coffee beverage intake did not induce changes in superoxide dismutase and glutathione peroxidase activities but was able to diminish lipid and protein oxidation in the anterior tibialis muscles of rats after exercise (P < 0.05), contributing to a reduction in the oxidative stress triggered by exercise. PMID:22173821

  4. Compositional, nutritional, and functional characteristics of instant teas produced from low- and high-quality black teas.

    PubMed

    Alasalvar, Cesarettin; Pelvan, Ebru; Ozdemir, Kübra Sultan; Kocadağlı, Tolgahan; Mogol, Burçe Ataç; Paslı, Ayça Ayfer; Ozcan, Nihat; Ozçelik, Beraat; Gökmen, Vural

    2013-08-01

    Two types of instant teas produced from low- and high-quality black teas were examined for their proximate composition, dietary fiber, minerals, water-soluble vitamins, total phenolic content, various antioxidant assays, phenolics (flavanols, condensed phenolics, and phenolic acids), alkaloids, and carotenoids as well as taste-active compounds (sugars, organic acids, and free amino acids). Some variations, albeit to different extents, were observed (p < 0.05) among these parameters between instant teas produced from low- and high-quality black teas. With respect to proximate composition, carbohydrate was the predominant component (56.68-59.84 g/100 g), followed by protein (19.31-19.86 g/100 g). Ash, moisture, and, to a lesser extent, dietary fiber and fat were also present in both instant teas. Thirteen minerals, four water-soluble vitamins, six flavanols, two alkaloids, three condensed phenolics, one phenolic acid, and one carotenoid were identified. Total phenolic content varied between 17.35 and 17.82 g of gallic acid equivalents (GAE)/100 g instant tea. With regard to antioxidant activities, three different assays such as oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and cupric ion reducing antioxidant capacity (CUPRAC) were measured. No significant differences (p > 0.05) in total phenolic, ORAC, TEAC, and CUPRAC contents between low- and high-quality instant teas were observed. With regard to taste-active compounds, 3 sugars, 5 organic acids, and 18 free amino acids were positively identified, of which fructose, tannic acid, and theanine predominated, respectively. The present work suggests that despite some differences, instant teas produced from low- and high-quality black teas should not be distinguished on the basis of their compositional, nutritional, and functional characteristics as well as taste-active compounds. PMID:23837397

  5. 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 su %7C ers 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 e %7C ectively detect and characterize quantum noise using carefully tailored ensembles of input states.

  6. 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

  7. Enhanced perception of terrain hazards in off-road path choice: stereoscopic 3D versus 2D displays

    NASA Astrophysics Data System (ADS)

    Merritt, John O.; CuQlock-Knopp, V. Grayson; Myles, Kimberly

    1997-06-01

    Off-road mobility at night is a critical factor in modern military operations. Soldiers traversing off-road terrain, both on foot and in combat vehicles, often use 2D viewing devices (such as a driver's thermal viewer, or biocular or monocular night-vision goggles) for tactical mobility under low-light conditions. Perceptual errors can occur when 2D displays fail to convey adequately the contours of terrain. Some off-road driving accidents have been attributed to inadequate perception of terrain features due to using 2D displays (which do not provide binocular-parallax cues to depth perception). In this study, photographic images of terrain scenes were presented first in conventional 2D video, and then in stereoscopic 3D video. The percentage of possible correct answers for 2D and 3D were: 2D pretest equals 52%, 3D pretest equals 80%, 2D posttest equals 48%, 3D posttest equals 78%. Other recent studies conducted at the US Army Research Laboratory's Human Research and Engineering Directorate also show that stereoscopic 3D displays can significantly improve visual evaluation of terrain features, and thus may improve the safety and effectiveness of military off-road mobility operation, both on foot and in combat vehicles.

  8. 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.

  9. Independent effects of local and global binocular disparity on the perceived convexity of stereoscopically presented faces in scenes.

    PubMed

    Matthews, Harold; Hill, Harold; Palmisano, Stephen

    2012-01-01

    Evidence suggests that experiencing the hollow-face illusion involves perceptual reversal of the binocular disparities associated with the face even though the rest of the scene appears unchanged. This suggests stereoscopic processing of object shape may be independent of scene-based processing of the layout of objects in depth. We investigated the effects of global scene-based and local object-based disparity on the compellingness of the perceived convexity of the face. We took stereoscopic photographs of people in scenes, and independently reversed the binocular disparities associated with the head and scene. Participants rated perceived convexity of a natural disparity ("convex") or reversed disparity ("concave") face shown either in its original context with reversed or natural disparities or against a black background. Faces with natural disparity were rated as more convincingly convex independent of the background, showing that the local disparities can affect perceived convexity independent of disparities across the rest of the image. However, the apparent convexity of the faces was also greater in natural disparity scenes compared to either a reversed disparity scene or a zero disparity black background. This independent effect of natural scene disparity suggests that the 'solidity' associated with natural scene disparities spread to enhance the perceived convexity of the face itself. Together, these findings suggest that global and local disparity exert independent and additive effects upon the perceived convexity of the face. PMID:22670345

  10. Distractions, distractions: does instant messaging affect college students' performance on a concurrent reading comprehension task?

    PubMed

    Fox, Annie Beth; Rosen, Jonathan; Crawford, Mary

    2009-02-01

    Instant messaging (IM) has become one of the most popular forms of computer-mediated communication (CMC) and is especially prevalent on college campuses. Previous research suggests that IM users often multitask while conversing online. To date, no one has yet examined the cognitive effect of concurrent IM use. Participants in the present study (N = 69) completed a reading comprehension task uninterrupted or while concurrently holding an IM conversation. Participants who IMed while performing the reading task took significantly longer to complete the task, indicating that concurrent IM use negatively affects efficiency. Concurrent IM use did not affect reading comprehension scores. Additional analyses revealed that the more time participants reported spending on IM, the lower their reading comprehension scores. Finally, we found that the more time participants reported spending on IM, the lower their self-reported GPA. Implications and future directions are discussed. PMID:19006461

  11. 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.

  12. 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. PMID:25983224

  13. Thermal-tempering analysis of bulk metallic glass plates using an instant-freezing model

    NASA Astrophysics Data System (ADS)

    Aydiner, C. C.; Ü:Ustü:Undag, E.; Hanan, J. C.

    2001-11-01

    The viscoelastic nature of bulk metallic glasses (BMGs), their low thermal conductivity, and the fast cooling used in their processing subject them to thermal tempering. This process leads to a residual stress state in which compression on the surface is balanced by tension in the interior. For the first time, we have calculated such stresses in metallic glasses by adapting an analytical instant-freezing model previously developed for silicate glasses. This model has been demonstrated to be reasonably accurate in predicting the final residual stresses, although, due to its very nature, it neglects transient effects. For an infinite plate geometry and employing processing parameters often used for metallic glasses, we predict that significant residual stresses can be generated in these materials during thermal tempering. Preliminary measurements conducted using the layer-removal method yield compressive residual stress values close to model predictions.

  14. Interpolating mass gap equation between the instant form and the front form of relativistic dynamics

    NASA Astrophysics Data System (ADS)

    Bradley, Colton; Ji, Chueng-Ryong

    2016-03-01

    We present a mass gap equation linking between the instant form dynamics and the light-front dynamics by interpolating them together with an interpolation variable. We discuss a nucleon dressed in pion loops with the psudovector πNN coupling and techniques in non-linear dynamics to achieve a numerical result. The equivalence of the light-front, equal-time and covariant formulations in meson-baryon interactions has been previously demonstrated. In particular, the self-energy of a nucleon dressed by pion loops has been discussed to show the universality of the leading nonanalytic behavior of the chiral dynamics consistent with QCD. In this poster, we take the previous self-energy calculation as the kernel of the integral equation and discuss the characteristic of the mass gap equation particularly in the limit of the light-front dynamics.

  15. Prospects of photoacoustic tomography

    PubMed Central

    Wang, Lihong V.

    2008-01-01

    Commercially available high-resolution three-dimensional optical imaging modalities—including confocal microscopy, two-photon microscopy, and optical coherence tomography—have fundamentally impacted biomedicine. Unfortunately, such tools cannot penetrate biological tissue deeper than the optical transport mean free path (∼1 mm in the skin). Photoacoustic tomography, which combines strong optical contrast and high ultrasonic resolution in a single modality, has broken through this fundamental depth limitation and achieved superdepth high-resolution optical imaging. In parallel, radio frequency-or microwave-induced thermoacoustic tomography is being actively developed to combine radio frequency or microwave contrast with ultrasonic resolution. In this Vision 20∕20 article, the prospects of photoacoustic tomography are envisaged in the following aspects: (1) photoacoustic microscopy of optical absorption emerging as a mainstream technology, (2) melanoma detection using photoacoustic microscopy, (3) photoacoustic endoscopy, (4) simultaneous functional and molecular photoacoustic tomography, (5) photoacoustic tomography of gene expression, (6) Doppler photoacoustic tomography for flow measurement, (7) photoacoustic tomography of metabolic rate of oxygen, (8) photoacoustic mapping of sentinel lymph nodes, (9) multiscale photoacoustic imaging in vivo with common signal origins, (10) simultaneous photoacoustic and thermoacoustic tomography of the breast, (11) photoacoustic and thermoacoustic tomography of the brain, and (12) low-background thermoacoustic molecular imaging. PMID:19175133

  16. Meaning of Interior Tomography

    PubMed Central

    Wang, Ge; Yu, Hengyong

    2013-01-01

    The classic imaging geometry for computed tomography is for collection of un-truncated projections and 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 has been elevated as a general imaging principle. Finally, a novel framework known as “omni-tomography” is being developed for grand fusion of multiple imaging modalities, allowing tomographic synchrony of diversified features. PMID:23912256

  17. 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

  18. 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…

  19. Student Perceptions of Using Instant Messaging Software to Facilitate Synchronous Online Class Interaction in a Graduate Teacher Education Course

    ERIC Educational Resources Information Center

    Wang, Lih-Ching Chen; Morgan, William R.

    2008-01-01

    This study investigated student perceptions of using instant messaging software for online interactive chapter discussions in a graduate teacher educational technology course. The criterion instrument was a 47-item scale that measured Chickering and Gamson's (1987) first four principles for good practice in undergraduate education, yielding…

  20. 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…

  1. 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,…

  2. 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

  3. 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…

  4. 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…

  5. 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…

  6. 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.

  7. 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.

  8. EDITORIAL: Sixth World Congress on Industrial Process Tomography (WCIPT6) Sixth World Congress on Industrial Process Tomography (WCIPT6)

    NASA Astrophysics Data System (ADS)

    Takei, Masahiro; Xu, Lijun

    2011-10-01

    We are pleased to publish this special feature on the Sixth World Congress on Industrial Process Tomography (WCIPT6) in Measurement Science and Technology. The international congress was successfully held in the campus of Beihang University, Beijing, China, from 6-9 September 2010. It was jointly organized by International Society for Industrial Process Tomography (ISIPT), North China Electric Power University (NCEPU) and Beihang University (BUAA). Process tomography is a tangible tool to visualize and determine the material distribution inside a process non-intrusively in real time. The internal features that can be monitored by process tomography are frequently encountered and required in the design of processes and industrial plants in the fields of chemical, oil, power and metallurgical engineering as well as many other activities such as food, material handling and combustion systems. One of the key characteristics of process tomography is to provide a direct impression and instant and clear understanding of a complex phenomenon. From the viewpoint of practical applications, industries all over the world are currently facing a number of daunting challenges including many wide-range and complex technical problems. The innovative technology of process tomography consistently contributes to providing better and better solutions to the problems as 'seeing is believing'. As a regular event, WCIPT is playing a more and more important role in addressing the challenges to overcome these problems. We are glad to see that this special feature provides a great opportunity for world-wide top-level researchers to discuss and make further developments in process tomography and its applications. The 20 articles included in this issue cover a wide range of relevant topics including sensors and sensing mechanisms, data acquisition systems and instrumentation, electrical, optical, acoustic and hybrid systems, image reconstruction and system evaluation, data and sensor fusion

  9. Stereoscopic visualization in the varioscope AR: a see-through head-mounted display for surgical navigation

    NASA Astrophysics Data System (ADS)

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

    2002-05-01

    Based on the Varioscope, a commercially available head mounted operating binocular, we have developed a head mounted display for augmented reality visualization that seamlessly fits into the infrastructure of a surgical navigation system. This head mounted display, called the Varioscope AR, is equipped with two miniature computer monitors that merge computer graphics with the view of the operating field as seen by the surgeon. Since the position of the Varioscope AR is being tracked by the navigation system's optical tracker, planning data such as the location of a lesion identified on preoperative volume images can be displayed in the correct position transparently overlaying the optical field of view. In order to assess the system's accuracy and the depth perception of a user aiming at a given target, we have designed a phantom for skull base surgery. 16 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 gelatine 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 using stereoscopic vision with this novel device had a success rate (defined as a first trial hit rate) of 81,5%. Using monoscopic vision, the success rate was found to be 50%. We conclude that the Varioscope AR is now mature for further cadaver tests and clinical studies.

  10. Stereoscopic motion analysis in densely packed clusters: 3D analysis of the shimmering behaviour in Giant honey bees

    PubMed Central

    2011-01-01

    Background The detailed interpretation of mass phenomena such as human escape panic or swarm behaviour in birds, fish and insects requires detailed analysis of the 3D movements of individual participants. Here, we describe the adaptation of a 3D stereoscopic imaging method to measure the positional coordinates of individual agents in densely packed clusters. The method was applied to study behavioural aspects of shimmering in Giant honeybees, a collective defence behaviour that deters predatory wasps by visual cues, whereby individual bees flip their abdomen upwards in a split second, producing Mexican wave-like patterns. Results Stereoscopic imaging provided non-invasive, automated, simultaneous, in-situ 3D measurements of hundreds of bees on the nest surface regarding their thoracic position and orientation of the body length axis. Segmentation was the basis for the stereo matching, which defined correspondences of individual bees in pairs of stereo images. Stereo-matched "agent bees" were re-identified in subsequent frames by the tracking procedure and triangulated into real-world coordinates. These algorithms were required to calculate the three spatial motion components (dx: horizontal, dy: vertical and dz: towards and from the comb) of individual bees over time. Conclusions The method enables the assessment of the 3D positions of individual Giant honeybees, which is not possible with single-view cameras. The method can be applied to distinguish at the individual bee level active movements of the thoraces produced by abdominal flipping from passive motions generated by the moving bee curtain. The data provide evidence that the z-deflections of thoraces are potential cues for colony-intrinsic communication. The method helps to understand the phenomenon of collective decision-making through mechanoceptive synchronization and to associate shimmering with the principles of wave propagation. With further, minor modifications, the method could be used to study

  11. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    NASA Astrophysics Data System (ADS)

    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.

  12. 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

  13. 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.

  14. 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

  15. Opioid use for Chronic Pain Management in Italy: Results from the Orthopedic Instant Pain Survey Project

    PubMed Central

    Fanelli, Guido; Cherubino, Paolo; Compagnone, Christian

    2014-01-01

    Pain is a common symptom in orthopedic patients, but is managed sub-optimally, partly due to scarce opioid use in severe cases. The aim of the Orthopedic Instant Pain Survey (POIS) was to evaluate changes in pain management in Italian orthopedic practice 2 years after a legislative change (Law 38/2010) simplifying opioid access for pain control. A web-based survey on the knowledge of this law and trends observed in clinical practice for severe pain treatment was administered to 143 Italian orthopedic specialists. In total, 101 (70%) respondents showed a high level of knowledge. Nevertheless, 54.5% stated that they do not use opioids for severe osteo-articular pain management. Main barriers to opioid use are fear of adverse events (61.4%), especially nausea/vomiting and constipation, and patient resistance (29.7%). A modest knowledge of pain classification was also demonstrated. Opioid use remains very limited in Italian orthopedic practice. Physicians’ fear of side effects showed poor knowledge of strategies for effective management of opioid-related adverse events, such as combined oral prolonged-release oxycodone/naloxone. Continuing educational programs could improve delivery of evidence-based pain management. PMID:25002934

  16. Instant transport media for biopsied soft tissue specimens: a comparative study.

    PubMed

    Patil, Shankargouda; Rao, Roopa S; Agarwal, Anveeta; Raj, A Thirumal

    2015-01-01

    Background. Formalin, a traditionally preferred fixative in the field of pathology, has restricted usage in private settings. Since its toxicity violates the Occupational Safety and Health Administration regulations, an eco-friendly alternative would be the need of the hour. Hence an instant media which is economical and nontoxic and enables easy transport of biopsied soft tissue specimens in its original state is of vital importance. Materials and Methods. Commercially available fresh goat buccal mucosa specimens were sliced into smaller bits of equal dimensions and placed in six different containers containing 20% honey, 30% jaggery, milk, and ice for 1 hr, 6 hours, 12 hours, and 24 hours each with formalin as a positive control. After the set time interval, the specimens were fixed in 10% buffered formalin for 24 hours followed by routine processing and staining. The histologic interpretations were a blinded procedure and evaluated by two experts. Results were statistically analysed. Results. 30% jaggery proved to be an ideal transport media showing high quality preservation after 24 hours. 20% honey and ice showed optimal tissue preservation up to 6 hours following which quality deteriorated. Tissues transported in milk showed poor preservation. Conclusion. 30% jaggery can be endorsed in routine histopathological analysis as a transport media. PMID:25793144

  17. Protein-triggered instant disassembly of biomimetic Layer-by-Layer films.

    PubMed

    Abdelkebir, Khalil; Gaudière, Fabien; Morin-Grognet, Sandrine; Coquerel, Gérard; Atmani, Hassan; Labat, Béatrice; Ladam, Guy

    2011-12-01

    Layer-by-Layer (LbL) coatings are promising tools for the biofunctionalization of biomaterials, as they allow stress-free immobilization of proteins. Here, we explore the possibility to immobilize phosvitin, a highly phosphorylated protein viewed as a model of bone phosphoproteins and, as such, a potential promotive agent of surface-directed biomineralization, into biomimetic LbL architectures. Two immobilization protocols are attempted, first, using phosvitin as the polyanionic component of phosvitin/poly-(L-lysine) films and, second, adsorbing it onto preformed chondroitin sulfate/poly-(L-lysine) films. Surprisingly, it is neither possible to embed phosvitin as the constitutive polyanion of the LbL architectures nor to adsorb it atop preformed films. Instead, phosvitin triggers instant massive film disassembly. This unexpected, incidentally detected behavior constitutes the first example of destructive interactions between LbL films and a third polyelectrolyte, a fortiori a protein, which might open a route toward new stimuli-responsive films for biosensing or drug delivery applications. Interestingly, additional preliminary results still indicate a promotive effect of phosvitin-containing remnant films on calcium phosphate deposition. PMID:22007998

  18. 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.

  19. 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.

  20. 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. PMID:24425909

  1. Instant effect of therapeutic abortion on serum steroid hormones during first trimester.

    PubMed

    Kisnisci, H A; Ayhan, A; Yucebilgin, S; Beksac, M S; Sefercioglu, A; Tasarkan, K

    1980-01-01

    Study focus was on the instant effect of therapeutic abortion under general anesthesia on serum levels of estradiol, progesterone and testosterone during the 1st trimester. Patients were 20 healthy women. Gestational age was determined clinically by the obstetrician on the basis of the menstrual history and estimation of the size of the uterus. The procedure was cervical dilatation by Hegar's dilators and curettage under general anesthesia. Venous blood samples were taken from each patient before dilatation and curettage and 3 hours after the termination of the procedure. In all samples serum estradiol, testosterone and progesterone levels were determined by radioimmunoassay. There was no significant correlation between the preoperative and postoperative serum estradiol, progesterone and testosterone levels. On the basis of the study findings it was concluded that there was no sudden effect of general anesthesia and therapeutic abortion on the serum estradiol, progesterone and testosterone levels. A 3-hour interval may be insufficient for the change of steriod hormones in serum samples. PMID:12262089

  2. 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.

  3. 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.

  4. [Psychosocial aspects of the direct path from infertility to the "instant family": are all risks known].

    PubMed

    Baor, Liora; Blickstein, Isaac

    2005-05-01

    Infertility is invariably described as a crisis event. Couples who encounter infertility are further challenged with the accompanied sense of profound losses: loss of health, sexuality, status and prestige, relationship, self-confidence, self-esteem, security, and the fantasy for biological parenthood. Fertility treatments (ART) create hope and cure for the problem on one hand, but place a tremendous burden on the couple's resources on the other. Assisted Reproductive Technologies (ART), carry potential risks for both the infant and for the mother, in addition to diverse negative psychosocial consequences for the couple. However, it seems that couples either ignore these risks or are unaware of them, and therefore, wish to accomplish the "instant family" (more than one child) via a shortcut (one pregnancy). Although it is impossible to ignore the numerous children born with the aid of ART, it is crucial that professionals inform the couple about the medical as well as the psychological consequences that accompany fertility treatments, to enable couples to make more realistic decisions. PMID:15931897

  5. Filtergraph: A Flexible Web Application for Instant Data Visualization of Astronomy Datasets

    NASA Astrophysics Data System (ADS)

    Burger, D.; Stassun, K. G.; Pepper, J. A.; Siverd, R. J.; Paegert, M. A.; De Lee, N. M.

    2013-10-01

    Filtergraph is a web application being developed by the Vanderbilt Initiative in Data-intensive Astrophysics (VIDA) to flexibly handle a large variety of astronomy datasets. While current datasets at Vanderbilt are being used to search for eclipsing binaries and extrasolar planets, this system can be easily reconfigured for a wide variety of data sources. The user loads a flat-file dataset into Filtergraph which instantly generates an interactive data portal that can be easily shared with others. From this portal, the user can immediately generate scatter plots, histograms, and tables based on the dataset. Key features of the portal include the ability to filter the data in real time through user-specified criteria, the ability to select data by dragging on the screen, and the ability to perform arithmetic operations on the data in real time. The application is being optimized for speed in the context of very large datasets: for instance, plot generated from a stellar database of 3.1 million entries render in less than 2 seconds on a standard web server platform. This web application has been created using the Web2py web framework based on the Python programming language.

  6. 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

  7. 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. PMID:24460803

  8. 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

  9. 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

  10. 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

  11. Instantly decodable network coding for real-time scalable video broadcast over wireless networks

    NASA Astrophysics Data System (ADS)

    Karim, Mohammad S.; Sadeghi, Parastoo; Sorour, Sameh; Aboutorab, Neda

    2016-01-01

    In this paper, we study real-time scalable video broadcast over wireless networks using instantly decodable network coding (IDNC). Such real-time scalable videos have hard deadline and impose a decoding order on the video layers. We first derive the upper bound on the probability that the individual completion times of all receivers meet the deadline. Using this probability, we design two prioritized IDNC algorithms, namely the expanding window IDNC (EW-IDNC) algorithm and the non-overlapping window IDNC (NOW-IDNC) algorithm. These algorithms provide a high level of protection to the most important video layer, namely the base layer, before considering additional video layers, namely the enhancement layers, in coding decisions. Moreover, in these algorithms, we select an appropriate packet combination over a given number of video layers so that these video layers are decoded by the maximum number of receivers before the deadline. We formulate this packet selection problem as a two-stage maximal clique selection problem over an IDNC graph. Simulation results over a real scalable video sequence show that our proposed EW-IDNC and NOW-IDNC algorithms improve the received video quality compared to the existing IDNC algorithms.

  12. Visual Iconic Patterns of Instant Messaging: Steps Towards Understanding Visual Conversations

    NASA Astrophysics Data System (ADS)

    Bays, Hillary

    An Instant Messaging (IM) conversation is a dynamic communication register made up of text, images, animation and sound played out on a screen with potentially several parallel conversations and activities all within a physical environment. This article first examines how best to capture this unique gestalt using in situ recording techniques (video, screen capture, XML logs) which highlight the micro-phenomenal level of the exchange and the macro-social level of the interaction. Of particular interest are smileys first as cultural artifacts in CMC in general then as linguistic markers. A brief taxonomy of these markers is proposed in an attempt to clarify their frequency and patterns of their use. Then, focus is placed on their importance as perceptual cues which facilitate communication, while also serving as emotive and emphatic functional markers. We try to demonstrate that the use of smileys and animation is not arbitrary but an organized interactional and structured practice. Finally, we discuss how the study of visual markers in IM could inform the study of other visual conversation codes, such as sign languages, which also have co-produced, physical behavior, suggesting the possibility of a visual phonology.

  13. 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

  14. 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.

  15. Applications of the Stroboscopic Tomography to Selected 2-Level Decoherence Models

    NASA Astrophysics Data System (ADS)

    Czerwiński, Artur

    2016-02-01

    In the paper we discuss possible applications of the so-called stroboscopic tomography (stroboscopic observability) to selected decoherence models of 2-level quantum systems. The main assumption behind our reasoning claims that the time evolution of the analyzed system is given by a master equation of the form dot {ρ } = {L} ρ and the macroscopic information about the system is provided by the mean values m i ( t j ) = T r( Q i ρ( t j )) of certain observables {Qi}_{i=1}r measured at different time instants {tj}_{j=1}p. The goal of the stroboscopic tomography is to establish the optimal criteria for observability of a quantum system, i.e. minimal value of r and p as well as the properties of the observables {Qi}_{i=1}r.

  16. Use of instant messaging predicts self-report but not performance measures of inattention, impulsiveness, and distractibility.

    PubMed

    Levine, Laura E; Waite, Bradley M; Bowman, Laura L

    2013-12-01

    We examined how young adults' use of instant messaging, text messaging, and traditional reading related to their self-reported experience of distractibility and impulsiveness and to their performance on computerized tasks designed to assess inattention and impulsive responses to visual stimuli. Participants reported their media use and completed self-report measures of impulsiveness (i.e., the Barratt Impulsiveness Scale) and distractibility for academic reading. They also completed performance based measures of inattention and impulsiveness using the Tests of Variables of Attention (T.O.V.A.(®)). Results demonstrated that instant message use was significantly related to higher levels of attentional impulsiveness and distractibility on the self-report measures, while traditional reading consistently predicted lower levels of impulsiveness and distractibility. However, media use was not significantly related to the performance measures of inattention and behavioral impulsiveness. PMID:23952624

  17. 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.

  18. Two features of sleep slow waves: homeostatic and reactive aspects--from long term to instant sleep homeostasis.

    PubMed

    Halász, Péter; Bódizs, Róbert; Parrino, Liborio; Terzano, Mario

    2014-10-01

    In this paper we reviewed results of sleep research that have changed the views about sleep slow wave homeostasis, which involve use-dependent and experience-dependent local aspects to understand more of the physiology of plastic changes during sleep. Apart from the traditional homeostatic slow-wave economy, we also overviewed research on the existence and role of reactive aspects of sleep slow waves. Based on the results from spontaneous and artificially evoked slow waves, we offer a new hypothesis on instant slow wave homeostatic regulation. This regulation compensates for any potentially sleep-disturbing events by providing instant "delta injections" to maintain the nightly delta level, thus protecting cognitive functions located in the frontal lobe. We suggest that this double (long-term /instant) homeostasis provides double security for the frontal lobes in order to protect cognitive functions. The incorporation of reactive slow wave activity (SWA) makes sleep regulation more dynamic and provides more room for the internalization of external influences during sleep. PMID:25192672

  19. In vitro assessment of potential intestinal absorption of some phenolic families and carboxylic acids from commercial instant coffee samples.

    PubMed

    López-Froilán, R; Ramírez-Moreno, E; Podio, N S; Pérez-Rodríguez, M L; Cámara, M; Baroni, M V; Wunderlin, D A; Sánchez-Mata, M C

    2016-06-15

    Coffee is one of the most consumed beverages in the world, being a source of bioactive compounds as well as flavors. Hydroxycinnamic acids, flavonols, and carboxylic acids have been studied in the samples of instant coffee commercialized in Spain. The studies about contents of food components should be complemented with either in vitro or in vivo bioaccessibility studies to know the amount of food components effectively available for functions in the human body. In this sense, a widely used in vitro model has been applied to assess the potential intestinal absorption of phenolic compounds and organic acids. The contents of hydroxycinnamic acids and flavonols were higher in instant regular coffee samples than in the decaffeinated ones. Bioaccessible phenolic compounds in most analyzed samples account for 20-25% of hydroxycinnamic acids and 17-26% of flavonols. This could mean that a great part of them can remain in the gut, acting as potential in situ antioxidants. Quinic, acetic, pyroglutamic, citric and fumaric acids were identified in commercial instant coffee samples. Succinic acid was found in the coffee blend containing chicory. All carboxylic acids showed a very high bioaccessibility. Particularly, acetic acid and quinic acid were found in higher contents in the samples treated with the in vitro simulation of gastrointestinal processes, compared to the original ones, which can be explained by their cleavage from chlorogenic acid during digestion. This is considered as a positive effect, since quinic acid is considered as an antioxidant inducer. PMID:27191052

  20. Extraction of rutin from Tartary buckwheat milling fractions and evaluation of its thermal stability in an instant fried noodle system.

    PubMed

    Cho, Yong Jin; Lee, Suyong

    2015-06-01

    Extraction conditions of rutin from buckwheat milling fractions were established and a rutin-enriched material (REM, 31.8g/100g of rutin) was successfully obtained by the ultrasonic-assisted ethanol method (steaming, 16-150 mesh particle size, 70% ethanol, and ultrasonication at 40°C for 30min). When REM was applied to instant fried noodles (1% and 2% by weight of wheat flour) for rutin fortification, the levels of rutin in the noodles were determined to be about 250-500mg/100g which corresponded to the recommended daily dose of rutin. While frying temperatures (150-190°C) and times (1-3min) did not negatively affect the level of rutin in the instant fried noodles, the distinct loss of rutin was observed after cooking. Furthermore, REM did not significantly affect the oil uptake and mechanical property of instant fried noodles. The strong antioxidant activity of rutin in REM contributed to retarding the oxidative deterioration of the noodles during storage. PMID:25624204