Science.gov

Sample records for aavso visual observations

  1. AAVSO Visual Sunspot Observations vs. SDO HMI Sunspot Catalog

    NASA Astrophysics Data System (ADS)

    Howe, R.

    2014-06-01

    (Abstract only) The most important issue with regard to using the SDO HMI data from the National Solar Observatory (NSO, http://www.nso.edu/staff/fwatson/STARA) is that their current model for creating sunspot counts does not split in groups and consequently does not provide a corresponding group count and Wolf number. As it is a different quantity, it cannot be mixed with the data from our sunspot networks. For the AAVSO with about seventy stations contributing each day, adding HMI sunspot data would anyway hardly change the resulting index. Perhaps, the best use of HMI data is for an external validation, by exploiting the fact that HMI provides a series that is rather close to the sunspot number and is acquired completely independently. So, it is unlikely to suffer from the same problems (jumps, biases) at the same time. This validation only works for rather short durations, as the lifetime of space instruments is limited and aging effects are often affecting the data over the mission. In addition, successive instruments have different properties: for example, the NSO model has not managed yet to reconcile the series from MDI and HMI. There is a ~10-15% jump. The first challenge that should be addressed by AAVSO using HMI data is the splitting in groups and deriving group properties. Then, together with the sunspot counts and areas per group, a lot more analyses and diagnostics can be derived (like the selective disappearance of the smallest sunspots?), that can help interpreting trends in the ratio SSN/other solar indices and many other solar effects.

  2. AAVSO Solar Observers Worldwide

    NASA Astrophysics Data System (ADS)

    Howe, R.

    2013-06-01

    (Abstract only) For visual solar observers there has been no biological change in the "detector" (human eye) - at century scales (eye + visual cortex) does not change much over time. Our capacity to "integrate" seeing distortions is not just simple averaging! The visual cortex plays an essential role, and until recently only the SDO-HMI (Solar Dynamics Observatory, Helioseismic and Magnetic Imager) has had the capacity to detect the smallest sunspots, called pores. Prior to this the eye was superior to photography and CCD. Imaged data are not directly comparable or substitutable to counts by eye, as the effects of sensor/optical resolution and seeing will have a different influence on the resulting sunspot counts for images when compared to the human eye. Also contributing to the complex task of counting sunspots is differentiating between a sunspot (which is usually defined as having a darker center (umbra) and lighter outer ring (penumbra)) and a pore, made even more complex by the conflicting definitions of the word "pore" in the solar context: "pore" can mean a small spot without penumbra or "pore" can mean a random intergranular blemish that is not a true sunspot. The overall agreement is that the smallest spot size is near 2,000 km or ~3 arc sec, (Loughhead, R. E. and Bray, R. J. 1961, Australian J. Phys., 14, 347). Sunspot size is dictated by granulation dynamics rather than spot size (cancellation of convective motion), and by the lifetime of the pore, which averages from 10 to 30 minutes. There is no specific aperture required for AAVSO observers contributing sunspot observations. However, the detection of the smallest spots is influenced by the resolution of the telescope. Two factors to consider are the theoretical optical resolution (unobstructed aperture), Rayleigh criterion: theta = 138 / D(mm), and Dawes criterion: theta = 116 / D(mm) (http://www.telescope-optics.net/telescope_resolution.htm). However, seeing is variable with time; daytime range will

  3. 20 Million Observations: The AAVSO International Database and Its First Century

    NASA Astrophysics Data System (ADS)

    Waagen, E. O.

    2012-06-01

    (Abstract only) The American Association of Variable Star Observers (AAVSO) turns 100 in 2011 - a century of service to the astronomical community! Another milestone was reached in 2011: the AAVSO International Database (AID) received its 20 millionth variable star observation! The AID contains observations of over 14,750 objects contributed by over 7,500 amateur and professional astronomers worldwide. Data on hundreds of objects extend from the AAVSO's founding in 1911 or earlier (mid-1800s) to present. Some objects' data are of shorter duration but of intense, high-precision coverage. Historical datasets come from published/unpublished professional/amateur observations, astronomical plate collections, and contributed archives of other variable star observing organizations. Hundreds of observations are added to the AID daily as observers upload their data in near real-time. Approximately 69% (~13.9M) of AID observations are visual, 30.4% (~6.2M) CCD (BVRI, unfiltered, Sloan colors, others), 0.5% (~75K) PEP (BVJH), and 0.1% (~17K) photographic/photovisual. Many objects have exclusively visual data, some PEP or CCD data only, and many a combination of types and bands. Objects range from young stellar objects through highly evolved stars. Included are intrinsic variables - pulsating (SX Phe stars through Miras and semiregulars) and eruptive (cataclysmic variables of all types) - and extrinsic variables - eclipsing binaries, rotating (RS CVns) - and exoplanets and suspected variables. Blazars, polars, quasars, HMXBs - today's AID is a thriving, exciting resource! The AID is maintained in a dynamic MySQL database, easily accessible to contributors and users alike through the AAVSO website (http://www.aavso.org). The Light Curve Generator, Quick Look page (recent observations), and Data Download form offer different ways to view/investigate your targets. Quality control performed from submission through validation ensures reliable data for your research. Visit the AAVSO

  4. 20 Million Observations: the AAVSO International Database and its First Century

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2011-05-01

    The American Association of Variable Star Observers (AAVSO) turns 100 in 2011 - a century of service to the astronomical community! Another milestone was reached in 2011: the AAVSO International Database (AID) received its 20 millionth variable star observation! The AID contains observations of over 14,750 objects contributed by over 7,500 amateur and professional astronomers worldwide. Data on hundreds of objects extend from the AAVSO's founding in 1911 or earlier (mid-1800's) to present. Some objects’ data are of shorter duration but of intense, high-precision coverage. Historical datasets come from published/unpublished professional/amateur observations, astronomical plate collections, and contributed archives of other variable star observing organizations. Hundreds of observations are added to the AID daily as observers upload their data in near real-time. Approximately 69% ( 13.9M) of AID observations are visual, 30.4% ( 6.2M) CCD (BVRI, unfiltered, Sloan colors, others), 0.5% ( 75K) PEP (BVJH), and 0.1% ( 17K) photographic/photovisual. Many objects have exclusively visual data, some PEP or CCD data only, and many a combination of types and bands. Objects range from young stellar objects through highly evolved stars. Included are intrinsic variables - pulsating (SX Phe stars through Miras and semiregulars) and eruptive (cataclysmic variables of all types) - and extrinsic variables - eclipsing binaries, rotating (RS CVns) - and exoplanets and suspected variables. Blazars, polars, quasars, HMXBs - today's AID is a thriving, exciting resource! The AID is maintained in a dynamic MySQL database, easily accessible to contributors and users alike through the AAVSO website (http://www.aavso.org). The Light Curve Generator, Quick Look page (recent observations), and Data Download form offer different ways to view/investigate your targets. Quality control performed from submission through validation ensures reliable data for your research. Visit the AAVSO website if

  5. Astronomical League Observing Programs Supported by the AAVSO (Abstract)

    NASA Astrophysics Data System (ADS)

    Simonsen, M.

    2016-06-01

    (Abstract only) The Astronomical League provides many different observing programs designed to provide direction and goals for League members. The programs have certificates and pins to recognize the observers' accomplishments and for demonstrating their observing skills with a variety of instruments and objects. The AAVSO supports a Variable Star Observing award and the Astronomical League has recently agreed to adopt a new Binocular Variable Star Program.

  6. Observing Blazar Variability: The GTN-AAVSO Collaboration

    NASA Astrophysics Data System (ADS)

    Spear, G.; Price, A.; Plait, P.; Graves, T.; Cominsky, L.; Mattei, J.

    2004-05-01

    The NASA/EPO group at Sonoma State University is creating the GLAST Ground-Based Telescope Network (GTN). The GTN is a series of telescopes and observers which will support the science and education goals of NASA's Gamma-Ray Large Area Space Telescope. The GTN is a collaboration with the American Association of Variable Star Observers (AAVSO), other amateurs, schools, and professionals. GLAST will observe gamma rays from high-energy sources such as blazars. The ground-based telescopes will observe GLAST targets to provide a multi-year baseline of variability characteristics. During the mission the network will observe these targets simultaneously with GLAST to provided multi-wavelength coverage. Because of recent improvements in the sensitivity of CCD detectors and the improved reliability of computer controlled (robotic) telescopes, amateurs and students can now obtain professional quality data, and can make substantial contributions to the science goals of space observatories such as GLAST. Because of the unpredictability of blazar variability it is important to obtain as many observations as possible. A distributed network of committed observers is ideally suited. Indeed, such a network is essential to accumulate the data needed to ultimately understand the variability mechanism and the production of the gamma rays in this type of active galaxy. Amateurs are ideally suited to provide this type of coverage while professionals are finding it increasingly difficult to obtain telescope time on small telescopes. We will describe the resource materials and tutorials that are available through the GTN and the AAVSO, the GTN blazar image archive, the AAVSO international database of magnitudes, and the various levels of contributions to provide the required science data. We will also show comparisons of blazar data accumulated by professionals, by the AAVSO, and by students. Finally we will provide a status report for the 0.3 meter robotic telescope system being

  7. Aperture Fever and the Quality of AAVSO Visual Estimates: mu Cephei as an Example

    NASA Astrophysics Data System (ADS)

    Turner, D. G.

    2014-06-01

    (Abstract only) At the limits of human vision the eye can reach precisions of 10% or better in brightness estimates for stars. So why did the quality of AAVSO visual estimates suddenly drop to 50% or worse for many stars following World War II? Possibly it is a consequence of viewing variable stars through ever-larger aperture instruments than was the case previously, a time when many variables were observed without optical aid. An example is provided by the bright red supergiant variable mu Cephei, a star that has the potential to be a calibrating object for the extragalactic distance scale if its low-amplitude brightness variations are better defined. It appears to be a member of the open cluster Trumpler 37, so its distance and luminosity can be established provided one can pinpoint the amount of interstellar extinction between us and it. mu Cep appears to be a double-mode pulsator, as suggested previously in the literature, but with periods of roughly 700 and 1,000 days it is unexciting to observe and its red color presents a variety of calibration problems. Improving quality control for such variable stars is an issue important not only to the AAVSO, but also to science in general.

  8. The AAVSO High Energy Network

    NASA Astrophysics Data System (ADS)

    Price, Aaron

    2004-06-01

    The AAVSO is expanding its International Gamma-Ray Burst Network to incorporate other high energy objects such as blazars and magnetic cataclysmic variables (polars). The new AAVSO High Energy Network will be collaborating with the Global Telescope Network (GTN) to observe bright blazars in support of the upcoming GLAST mission. We also will be observing polars in support of the XMM mission. This new network will involve both visual and CCD obsrvers and is expected to last for many years.

  9. The GTN-AAVSO Blazar Program

    NASA Astrophysics Data System (ADS)

    Spear, G. G.; Mattei, J. A.; Price, A.; Graves, T.; Borders, T.; Slater, G.; Cominsky, L. R.

    2002-12-01

    The GLAST Telescope Network (GTN) is a collaboration among observers and small observatories who will obtain observations of base-line activity levels and follow-up observations for bright blazars. These AGNs have their jets pointed directly toward us, and are one of the key science objectives for NASA's Gamma-ray Large Area Space Telescope (GLAST) mission. Funded by the GLAST Education and Public Outreach Program, the GTN consists of students, teachers, amateur astronomers, small college observatories, and professional astronomers. The American Association of Variable Star Observers (AAVSO) is a non-profit international scientific and educational organization of thousands of advanced amateur and professional astronomers interested in stars or star-like objects that change in brightness. With millions of variable star observations dating back more than 90 years, the AAVSO has unique experience with handling, processing, and displaying large amounts of data and with coordinating observers from every corner of the globe. The GTN-AAVSO blazar program will recommend observing programs, and provide advice and mentoring for observing techniques and data reduction. The program will archive magnitude estimates and measurements of blazars, as well as CCD images of blazar fields. The GTN-AAVSO program will employ the AAVSO database system and lightcurve generator (http://www.aavso.org/adata/curvegenerator.shtml) to archive magnitude estimates. The magnitudes will either be visual estimates or CCD measurements. Magnitudes are submitted online, and will be immediately available to the public for use in planning observing programs and estimating current activity levels. The GTN-AAVSO program will also employ the online image archiving system developed by the GTN. Images of blazar fields will be available for subsequent analysis by contributors to the program, and by the GLAST science team for mission planning and follow-up studies. We will present examples of the AAVSO

  10. Professional Astronomers in Service to the AAVSO

    NASA Astrophysics Data System (ADS)

    Saladyga, M.; Waagen, E. O.

    2012-06-01

    (Abstract only) Throughout its 100-year history, the American Association of Variable Star Observers (AAVSO) has welcomed professional astronomers to its membership ranks, and has encouraged their participation as organization leaders. The AAVSO has been fortunate to have over 60 distinguished professionals serve as officers (Directors, Presidents, Council), and as participants in its various scientific and organizational committees.

  11. Professional Astronomers in Service to the AAVSO

    NASA Astrophysics Data System (ADS)

    Saladyga, Michael; Waagen, E. O.

    2011-05-01

    Throughout its 100-year history, the American Association of Variable Star Observers (AAVSO) has welcomed professional astronomers to its membership ranks, and has encouraged their participation as organization leaders. The AAVSO has been fortunate to have many distinguished professionals serve as officers (Directors, Presidents, Council), and as participants in its various scientific and organizational committees.

  12. The GTN-AAVSO Blazar Program

    NASA Astrophysics Data System (ADS)

    Cominsky, L. R.; Spear, G. G.; Graves, T.; Slater, G.; Price, A.

    2004-08-01

    The GLAST Telescope Network (GTN) is a collaboration among students, teachers, amateur astronomers, small college observatories, and professional astronomers who will obtain observations of base-line activity levels and follow-up observations for bright blazars, one of the key science objectives for NASA's Gamma-ray Large Area Space Telescope (GLAST) mission. A key partner in the GTN is the American Association of Variable Star Observers (AAVSO, a non-profit international scientific and educational organization that has considerable experience with handling, processing, and displaying large amounts of data and with coordinating observers from every corner of the globe. The GTN-AAVSO blazar program will recommend observing sequences, and provide advice and mentoring for observing techniques and data reduction. The program will archive magnitude estimates using the AAVSO database system and lightcurve generator, as well as CCD images of blazar fields. The program will also employ the online image archiving system developed by the GTN. Images of blazar fields will be available for subsequent analysis by contributors to the program, and by the GLAST science team for mission planning and follow-up studies. We will present examples of the AAVSO lightcurve generator, examples of the GTN image archive system, plus examples of the data we are currently accumulating. The GTN-AAVSO collaboration is partially funded by the NASA's GLAST Education and Public Outreach Program.

  13. Long-Term Visual Light Curves and Modern Visual Observing in Astrophysics

    NASA Astrophysics Data System (ADS)

    Percy, John R.

    2011-05-01

    Thanks to organizations such as the AAVSO, visual observations of variable stars have scientific strengths: they are numerous, sustained, and standardized. Though many have predicted the demise of visual observation, the demand for visual observations increased dramatically in the last quarter of the 20th century. In addition to their value in detecting, timing, and studying outbursts in CVs, fadings in R CrB stars, and eclipses in binaries, they are uniquely useful in studying the behavior of pulsating stars, especially slow, irregular, and long-term behavior. In this presentation, I will give a general review of this topic, but will highlight the nature and implications of my own work on such stars: Mira stars, smaller-amplitude pulsating red giants, RV Tauri and SRd variables, and supergiant variables across the H-R diagram. This work includes studies of variability, periodicity, multiperiodicity, irregularity, period changes (systematic and random), and long-term variability of unknown cause. This work provides important information about stellar processes, properties, structure, and evolution. For studying long-term variability, the AAVSO International Database is a uniquely valuable resource. Much of this work has been carried out by students, motivated by the excitement of doing real science, with real data, thereby developing and integrating their science, math, and computing skills. We present at AAVSO meetings, and publish in the JAAVSO, as feedback and motivation to observers. Acknowledgements: I thank NSERC Canada for research support, my students for their work and inspiration, and the AAVSO staff and observers who make this work possible.

  14. Utilizing the AAVSO's Variable Star Index (VSX) In Undergraduate Research Projects

    NASA Astrophysics Data System (ADS)

    Larsen, Kristine

    2016-01-01

    Among the many important services that the American Association of Variable Star Observers (AAVSO) provides to the astronomical community is the Variable Star Index (VSX - https://www.aavso.org/vsx/). This online catalog of variable stars is the repository of data on over 334,000 variable stars, including information on spectral type, range of magnitude, period, and type of variable, among other properties. A number of these stars were identified as being variable through automated telescope surveys, such as ASAS (All Sky Automated Survey). The computer code of this survey classified newly discovered variables as best it could, but a significant number of false classifications have been noted. The reclassification of ASAS variables in the VSX data, as well as a closer look at variables identified as miscellaneous type in VSX, are two of many projects that can be undertaken by interested undergraduates. In doing so, students learn about the physical properties of various types of variable stars as well as statistical analysis and computer software, especially the VStar variable star data visualization and analysis tool that is available to the astronomical community free of charge on the AAVSO website (https://www.aavso.org/vstar-overview). Two such projects are described in this presentation, the first to identify BY Draconis variables erroneously classified as Cepheids in ASAS data, and the second to identify SRD semiregular variables misidentified as "miscellaneous" in VSX.

  15. The AAVSO Photoelectric Photometry Program in Its Scientific and Socio-Historic Context

    NASA Astrophysics Data System (ADS)

    Percy, J. R.

    2012-06-01

    In this paper, I review the work of the AAVSO in the area of photoelectric photometry (PEP). This work was influenced by several trends: in science, in technology, and in the sociology of amateur astronomy. Through the 1980s, the AAVSO photoelectric photometry program competed with other such programs and, in recent years, has been overshadowed by CCD photometry programs. Nevertheless, the AAVSO PEP program has, through careful organization, motivation, and feedback, produced extensive scientific results, and can continue to do so. In the case of my own research, AAVSO PEP observations have also contributed significantly to the education of my students.

  16. The Birch Street Irregulars: mysteries found and resolved in the AAVSO data archives

    NASA Astrophysics Data System (ADS)

    Beck, Sara J.; Saladyga, Michael; Mattei, Janet A.

    As they evaluate AAVSO data, AAVSO technical staff members run across several kinds of errors. This paper takes a humorous and Sherlock Holmes-style look at some of the most common kinds of errors detected, from observers recording the wrong Julian Date, misidentifying stars, transposing entries on the observer form, to garden-variety data entry errors.

  17. The AAVSO Widow—Or Should We Say Spouse?

    NASA Astrophysics Data System (ADS)

    Williams, T. R.

    2012-06-01

    In past discussions of AAVSO observers over our first century of progress, the familial consequences of membership received little attention. However, non-astronomer friends commonly ask AAVSO observers, “But how does your wife feel about your spending so much time at the telescope and not in bed with her?” Although our Directors have not all been “observers,” they too are forced to keep unusual office hours, answer telephones in the middle of the night, and so on. This paper attempts to portray the many surprising ways in which the AAVSO spouse (not all observers are male nor directors female!) responds to their partner’s pre-occupation with variable stars.

  18. The AAVSO as a Resource for Variable Star Research

    NASA Astrophysics Data System (ADS)

    Kafka, Stella

    2016-07-01

    The AAVSO was formed in 1911 as a group of US-based amateur observers obtaining data in support of professional astronomy projects. Now, it has evolved into an International Organization with members and observers from both the professional and non-professional astronomical community, contributing photometry to a public photometric database of about 22,000 variable objects, and using it for research projects. As such, the AAVSO's main claim to fame is that it successfully engages backyard Astronomers, educators, students and professional astronomers in astronomical research. I will present the main aspects of the association and how it has evolved with time to become a premium resource for variable star researchers. I will also discuss the various means that the AAVSO is using to support cutting-edge variable star science, and how it engages its members in projects building a stronger international astronomical community.

  19. The AAVSO International GRB Network

    NASA Astrophysics Data System (ADS)

    Price, Aaron

    2003-04-01

    The AAVSO International GRB Network provides services to both amateurs and professionals to help detect GRB afterglows. The network leverages the unique abilities of amateur astronomers to offer global coverage to eliminate geographic and climatic restrictions to GRB alert reaction times. Additionally, public outreach is a critical component of the network and automated online chart making procedures have made it a useful tool for professionals. The financial support of NASA and the Curry Foundation is gratefully appreciated.

  20. Visual observations over oceans

    NASA Technical Reports Server (NTRS)

    Terry, R. D.

    1979-01-01

    Important factors in locating, identifying, describing, and photographing ocean features from space are presented. On the basis of crew comments and other findings, the following recommendations can be made for Earth observations on Space Shuttle missions: (1) flyover exercises must include observations and photography of both temperate and tropical/subtropical waters; (2) sunglint must be included during some observations of ocean features; (3) imaging remote sensors should be used together with conventional photographic systems to document visual observations; (4) greater consideration must be given to scheduling earth observation targets likely to be obscured by clouds; and (5) an annotated photographic compilation of ocean features can be used as a training aid before the mission and as a reference book during space flight.

  1. Small-amplitude red variables in the AAVSO photoelectric photometry program: period analysis

    NASA Astrophysics Data System (ADS)

    Percy, John R.; Yu, Lawrence

    The AAVSO photoelectric photometry program was established about a decade ago by Janet A. Mattei and John R. Percy in order to obtain long-term, high-precision observations of variables which (at least on some time scales) show variations which are too small to be monitored effectively by visual techniques. As of 1992, the photoelectric archive contained over 7000 observations in total (Landis, Mattei, and Percy 1992, IBVS No, 3739). Most of the stars in the photoelectric program are red variables. With almost a decade of data on these stars, it is now possible to perform an effective period analysis. This we have done using a Fourier analysis program generously provided to the variable star community by Dr. E.P. Belserene. We report the results of the analysis here. Many of the stars show variability on two distinct time scales: tens of days (presumably due to pulsation) and hundreds of days (cause unknown).

  2. Reconsidering the History of the AAVSO-Part I

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.

    2001-06-01

    A review of the history of the American Association of Variable Star Observers (AAVSO) reveals that its development in the first half of the twentieth century requires reconsideration in two important respects. This first part of a two-part paper eals with one historical issue, the founding of the association and it operation during its first six years, including the role played by Edward Charles Pickering, and Harvard College Observatory, and recognizes that William Tyler Olcott played a more prominent role than has previously been acknowledged.

  3. Analysis of the AAVSO light curves of 21 dwarf novae

    SciTech Connect

    Szkody, P.; Mattei, J.A.

    1984-12-01

    Measurements of all observed outbursts of 21 dwarf novae during a three-year interval (JD2442300-JD2443300), using the data records of the AAVSO, are reported. Relationships among the rise time, outburst length, decline time, quiescent interval, maximum V magnitude, and physical-system parameters (such as orbital period and masses of the component stars) were investigated. The results confirm some, but not all, of the correlations previously found for the best-studied system SS Cyg and other less consistent surveys. The long-outburst and short-outburst separation characteristic of the SU UMa class are used to identify several prime suspects for this group.

  4. The AAVSO Photoelectric Photometry Program in its Scientific and Socio-Historic Context

    NASA Astrophysics Data System (ADS)

    Percy, John R.

    2011-05-01

    Photoelectric photometry began in the 1900s through the work of Guthnick, Stebbins, and others who constructed and used photometers based on the recently-discovered photoelectric effect. The mid 20th century saw a confluence of several areas of amateur interest: astronomy, telescope making, radio and electronics, and general interest in space. This is the time when AAVSO photoelectric photometry (PEP) began, with observers using mostly hand-built photometers on hand-built telescopes. The 1980s brought a revolution: affordable off-the-shelf solid-state photometers, and infrastructure such as the International Amateur-Professional Photoelectric Photometry (IAPPP) conferences, books, and journal. The AAVSO developed a formal PEP program in the early 1980s. Its emphasis was on long-term monitoring of pulsating red giants. It was competing, not always successfully, with programs such as active sun-like binaries (RS CVn stars) which offered "instant gratification" in the form of publicity and quick publications. Nevertheless, the AAVSO PEP program has, through careful organization, motivation, and feedback to observers, produced extensive scientific results. In this presentation, I shall describe, as examples, my own work, its scientific significance, its educational benefit to dozens of my students, and its satisfaction to the observers. To some extent, the AAVSO PEP program has been superceded by its CCD program, but there is still a useful place for ongoing PEP observations of thousands of variable stars. Reference: http://www.aavso.org/sites/default/files/newsletter/PEP/lastpepnl.pdf Acknowledgements: I thank NSERC Canada for research support, my students, and AAVSO staff and observers, especially Howard Landis.

  5. AAVSO and the International Year of Light (Poster abstract)

    NASA Astrophysics Data System (ADS)

    Larsen, K.

    2015-06-01

    (Abstract only) The United Nations General Assembly has officially designated 2015 to be the International Year of Light (IYL). Modeled in part on the earlier International Year of Astronomy (IYA), this cross-disciplinary, international educational and outreach project will celebrate the importance of light in science, technology, cultural heritage, and the arts. It ties in with several important anniversaries, such as the 1000th anniversary of the publication of Ibn Al Haythem's “Book of Optics,” the 150th anniversary of Maxwell's equations of electromagnetism, the centenary of Einstein's General Theory of Relativity, and the 50th anniversary of the discovery of the Cosmic Microwave Background Radiation. Because variable stars are defined as such due to the variability of the light we observe from them, all of the AAVSO programs, regardless of type of variable or instrumentation (eye, DSLR, PEP, or CCD) have natural tie-ins to the study of light. This poster will highlight a number of specific ways that AAVSO members and the organization as a whole can become intimately involved with this unique outreach opportunity.

  6. T Tauri stars observing campaign

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-12-01

    Darryl Sergison (University of Exeter) has requested AAVSO assistance with a campaign he is carrying out on five T Tauri stars. This study is the one for which AAVSO observers carried out a preliminary campaign last year (see Alert Notice 473 and Special Notice #306). The star list is revised and expanded from last year's list of targets. This campaign will run from now at least through the end of the 2013-2014 observing season. This is part of an on-going study into the nature of pre-main-sequence low mass stars, using time series optical spectroscopy and UV-Visual-IR photometry and offers a great opportunity for professional-amateur collaboration as the objects (with V magnitudes of 10-13) are well within the reach of photometry by small telescopes. Amateur observations are uniquely useful in the study of chaotically variable young stars as they offer crucial datapoints in the light curve between observations made by professional telescopes. Targets are BP Tau, DN Tau, V827 Tau, V1068 Tau, and V1264 Tau. Finder charts with sequences may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and instructions.

  7. T Tauri stars observing campaign

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-11-01

    Darryl Sergison (U. Exeter) requested AAVSO assistance with a campaign he is organizing on six T Tauri stars (RY Tau, DN Tau, DR Tau, and three to be announced). In September/October 2013 he and his Ph.D. supervisor Tim Naylor (U. Exeter) are undertaking a study into the nature of pre-main-sequence low mass stars, using time series optical spectroscopy and UV-Visual-IR photometry to build a clearer picture of the environment around young solar-type stars and characterize their various disc, accretion, and outflow structures. To begin building light curves in advance of the official study, visual observations and BVRcIc CCD photometry are requested from now through the 2013-2014 observing season at least. They are hoping to investigate periodicity for a range of phenomena on timescales of months to hours, so visual estimates ranging from monthly to twice in a night are requested. For photometry, low cadence is useful, higher cadence (hourly or long time series) is better! Spectroscopy is also requested, particularly around H-alpha (6563Å) if the resolution is greater than a few thousand. Finder charts with sequences may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  8. Spurious One-Month and One-Year Periods in Visual Observations of Variable Stars

    NASA Astrophysics Data System (ADS)

    Percy, J. R.

    2015-12-01

    Visual observations of variable stars, when time-series analyzed with some algorithms such as DC-DFT in vstar, show spurious periods at or close to one synodic month (29.5306 days), and also at about a year, with an amplitude of typically a few hundredths of a magnitude. The one-year periods have been attributed to the Ceraski effect, which was believed to be a physiological effect of the visual observing process. This paper reports on time-series analysis, using DC-DFT in vstar, of visual observations (and in some cases, V observations) of a large number of stars in the AAVSO International Database, initially to investigate the one-month periods. The results suggest that both the one-month and one-year periods are actually due to aliasing of the stars' very low-frequency variations, though they do not rule out very low-amplitude signals (typically 0.01 to 0.02 magnitude) which may be due to a different process, such as a physiological one. Most or all of these aliasing effects may be avoided by using a different algorithm, which takes explicit account of the window function of the data, and/or by being fully aware of the possible presence of and aliasing by very low-frequency variations.

  9. Request for observations of GW Lib in support of HST observations

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2011-03-01

    Dr. Paula Szkody (University of Washington) has requested AAVSO help in monitoring the cataclysmic variable GW Lib for HST observations scheduled during the week of 2011 April 7-11 UT. Dr. Szkody also observed this object with HST in March 2010 (see AAVSO Alert Notice 417). AAVSO observations are needed to ensure that the object is not in outburst when observed with HST, as it could damage the instrument if it were to go into outburst. AAVSO observations will be used to make a go/no go decision when the observing window opens, and will also be used in the analysis of the resulting data. At the end of March the schedulers will give Dr. Szkody the exact date of the HST observations, and an AAVSO Special Notice will be issued. Dr. Szkody requests nightly monitoring of this object from now until the observing window opens, intensive monitoring during the 24-48 hour period during which observations will be made, and nightly observations for the week following the HST observations. GW Lib is part of a larger study of pulsating white dwarf primaries in cataclysmic variables. In particular, Szkody and collaborators are investigating the effects that higher temperatures and larger rotation velocities caused by accretion have on the pulsation behavior. In these HST observations, they plan to measure the temperature of the white dwarf at minimum. GW Lib is magnitude ~16.8 visual/unfiltered. V filter is preferred for CCD observations, but B, Rc, and Ic may also be used. Detection of the variable itself is not required unless you can reach V=16.8 in reasonable time, but please use sufficient exposure to detect at least the V=143 comparison star or V=147 with a S/N of 10 and report the observation as a "fainter-than" observation. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  10. An Unfinished but Closed Chapter in AAVSO History

    NASA Astrophysics Data System (ADS)

    Williams, T. R.

    2005-08-01

    In thirty years of service as the AAVSO's director, Janet Akyüz Mattei left an indelible mark on the organization. The AAVSO underwent nearly continuous expansion of services to members and to the professional community of variable star astronomy during her tenure. Under her leadership, the association flourished and became recognized internationally as the leading variable star organization. Unfortunately, the final recognition that was richly deserved by Mattei, a retirement in which to enjoy the fruits of this effort, was denied her by her sudden illness and passing.

  11. THE SHAPE OF LONG OUTBURSTS IN U GEM TYPE DWARF NOVAE FROM AAVSO DATA

    SciTech Connect

    Cannizzo, John K.

    2012-10-01

    We search the American Association of Variable Star Observers (AAVSO) archives of the two best-studied dwarf novae in an attempt to find light curves for long outbursts that are extremely well characterized. The systems are U Gem and SS Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high-fidelity Kepler data for superoutbursts (SOs) of some members of the SU UMa subclass of dwarf novae. For the vast majority of AAVSO data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long-term monitoring with digital photometry yields high-fidelity light curves. We report the discovery of embedded precursors in two of three candidate long outbursts. This is the first time that such embedded precursors have been found in dwarf novae above the period gap in other than kepler data, and reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and SOs in systems below the period gap constitute a unified class. The thermal-tidal instability to account for SOs in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems-U Gem and SS Cyg-argues for a more general mechanism to explain long outbursts.

  12. Observational Properties of Synthetic Visual Binary Catalog

    NASA Astrophysics Data System (ADS)

    Nurmi, P.

    2004-08-01

    Forthcoming astrometric missions will observe a huge number of new binaries from which a large fraction will be visual binaries. Detailed planning of optimal detection procedures requires pre-launch information about the observational properties of expected visual binaries. Hence, a synthetic binary catalog is created and analyzed for observational properties of visual binary stars. These results help to understand what kind of binaries we expect to find in the final output catalogs of astrometric missions. These results represent `true' binary distributions if all of them would be observed. All real observational projects or astrometric satellites sample only small fractions of these populations depending on the observational capabilities of the missions. In this study we consider only relative numbers with respect to the total number of binary stars assumed to exist in the sky down to the magnitude limit depending on the astrometric mission.

  13. Monitoring of the dwarf nova U Geminorum in support of HST observations

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-12-01

    Dr. Michael Shara (American Museum of Natural History, Columbia University) requested dense coverage of the dwarf nova U Gem in support of HST Cosmic Origins Spectrograph (COS) observations scheduled now through February 20, 2013. The purpose of the AAVSO observations is twofold. First, they are to provide status information to the HST schedulers so they can be certain U Gem will not be in outburst during the observations. Second, they are to be used for correlation with and interpretation of spectra obtained by HST/COS in an effort to determine the dominant energy source in dwarf novae (and thus the physical mechanism of dwarf novae outbursts), fundamental information still not known about this class of objects (current theories do not explain all of the observational evidence). Visual observations and multicolor photometry of U Gem are requested through March 7, 2013. Calibrated UBVRcIc CCD observations are particularly requested; U-band photometry is especially valuable as HST/COS will be observing U Gem in the ultraviolet. Finder charts with sequences may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

  14. Observations of AA Tau requested to schedule XMM-Newton

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-08-01

    Dr. Hans Moritz Guenther (Harvard-Smithsonian Center for Astrophysics) has requested nightly observations of the classical T Tauri star AA Tau in order to schedule x-ray observations with XMM-Newton that have been planned for between 2013 August 15 and September 15. The purpose of the AAVSO observations is to determine whether AA Tau is at a suitable magnitude for the satellite observations. Taurus is difficult to observe during this time period but that is exactly why AAVSO assistance is needed! AA Tau is a morning object, and also, many of the professional ground-based telescopes are offline because of the US southwest monsoon season. Since it is critical to know the brightness of AA Tau, AAVSO observations will be truly essential. Nightly visual and snapshot (not more than once per night) observations beginning now and continuing through September 20 are needed. Coverage beginning ahead of the XMM window is requested because there is a one- to two-week lead time for the target to be inserted into the telescope schedule. Continuing the nightly observations a few days beyond the end of the XMM window will give better optical context for the x-ray data. AA Tau ranges between ~12.8V and ~16.1V; since December 2011 or earlier it has been at ~14.5V. The most recent observation in the AAVSO International Database shows it at 14.779V on 2013 Feb 5 (J. Roe, Bourbon, MO). Dr. Guenther writes, "AA Tau is surrounded by a thick accretion disk which is seen nearly edge-on. For decades the light curve of AA Tau showed regular eclipsing events when the accretion funnel rotated through the line of sight. However, earlier this year J. Bouvier and his group found that this behavior changed dramatically: AA Tau now seems to be deeply absorbed all the time (V band 14.5 mag). In collaboration with this group we will perform X-ray observations of AA Tau with the XMM-Newton satellite." Finder charts with sequence may be created using the AAVSO Variable Star Plo! tter (http://www.aavso

  15. Skylab 4 visual observations project report

    NASA Technical Reports Server (NTRS)

    Kaltenbach, J. L.; Lenoir, W. B.; Mcewen, M. C.; Weitenhagen, R. A.; Wilmarth, V. R.

    1974-01-01

    The Skylab 4 Visual Observations Project was undertaken to determine the ways in which man can contribute to future earth-orbital observational programs. The premission training consisted of 17 hours of lectures by scientists representing 16 disciplines and provided the crewmen information on observational and photographic procedures and the scientific significance of this information. During the Skylab 4 mission, more than 850 observations and 2000 photographs with the 70-millimeter Hasselblad and 35-millimeter Nikon cameras were obtained for many investigative areas. Preliminary results of the project indicate that man can obtain new and unique information to support satellite earth-survey programs because of his inherent capability to make selective observations, to integrate the information, and to record the data by describing and photographing the observational sites.

  16. Impact of visual fatigue on observer performance

    NASA Astrophysics Data System (ADS)

    Krupinski, Elizabeth A.; Berbaum, Kevin S.; Caldwell, Robert

    2009-02-01

    Our overall hypothesis is that current radiology practice produces oculomotor fatigue reducing diagnostic accuracy. The goal of this study is to determine whether accommodative stability and diagnostic accuracy are reduced following digital radiology interpretation. We are collecting data at two points in time - once in the morning prior to diagnostic reading and once in the afternoon after reading. Subjects are completing surveys about their current physical status and number of hours spent reading that day along and the type of images read. We are measuring accommodation using the WAM- 5500 Auto Refkeratometer. Subjects view bone images with subtle fractures and dislocations to determine if a fracture is present, locate it, and provide rating of their decision confidence to be used in a ROC analysis of the data. Preliminary results confirm our previous findings that we can measure visual fatigue. Radiologists are less able to focus on a distinct point, especially at near distances, after a day of reading images on digital displays as opposed to before any reading takes place. The SOFI and SSQ measures also indicate that radiologists are more fatigued at the end of a day's reading as compared to before. The confidence ratings are being evaluated using ROC techniques. The results so far suggest a reduction in diagnostic accuracy with tired eyes. Preliminary data from measuring visual accommodation and observer performance support our hypothesis that radiologists suffer visual fatigue after a day reading diagnostic images from digital displays reducing interpretation accuracy.

  17. Monitoring of RU Peg requested for Swift observations

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-06-01

    Dr. Koji Mukai (Universities Space Research Association/NASA Goddard Space Flight Center) has requested AAVSO observers' assistance in monitoring the SS Cyg-type dwarf nova RU Peg in support of target-of-opportunity observations with the NASA Swift satellite during an outburst. His observations will be targeted during the rise to outburst and during late decline from outburst. Thus, your prompt notification to AAVSO Headquarters of activity in RU Peg will be crucial to the success of this campaign. Dr. Mukai writes: "In the famous AAVSO/EUVE/RXTE campaign on SS Cyg (Mattei et al. 2000JAVSO..28..160M), the hard X-ray flux went up (with a delay) during the rise, then suddenly dropped; there was a corresponding flux enhancement episode during the decline. We know that, during the peak of the outburst, many dwarf novae are hard X-ray fainter than in quiescence (with a few exceptions, like U Gem). However, the hard X-ray enhancement episodes seen in SS Cyg have never been obs! erved in other dwarf novae. We have proposed a hypothesis that this is related to the mass of the accreting white dwarf; only dwarf novae with a relatively massive white dwarf show the hard X-ray enhancement. If that's true, we may well see similar enhancement in RU Peg, which is thought to have a massive white dwarf. Even if this hypothesis is completely wrong, RU Peg is a good target for an SS Cyg-like campaign, since it's X-ray bright during quiescence." Visual and CCD observations (filtered preferred to unfiltered) are appropriate for this campaign. Observers are requested to monitor RU Peg duning minimum, throughout the next outburst, and after return to minimym, and report their observations in a timely manner. If RU Peg appears to be brightening from minimum, please report your observations immediately to the AAVSO. If it is brighter than magnitude 12.3, please also send an email report to Elizabeth Waagen (eowaagen@aavso.org) and Matthew Templeton (matthewt@aavso.org). Please be aware that

  18. EE Cep observations requested for upcoming eclipse

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2014-07-01

    The AAVSO requests observations for the upcoming eclipse of EE Cephei, a long-period eclipsing variable. EE Cep has a period of 2,050 days, and shows strong variations in the eclipse light curve from one event to the next. Observations are needed to study the morphology of the upcoming eclipse, which will be used to better understand the shape of the eclipsing disk and how it precesses. Mid-eclipse is predicted to be August 23, 2014, but the early stages of the eclipse may begin as much as a month earlier. EE Cep is being observed by a number of amateur and professional astronomers using multiple telescopes at multiple wavelengths. Among these is a collaboration (see https://sites.google.com/site/eecep2014campaign/) headed by Cezary Galan at the Nicolaus Copernicus Astronomical Center in Poland; several individual AAVSO observers are already participating in this effort. The AAVSO is not currently a partner in that campaign, but all data submitted to the AAVSO will be publicly available. The AAVSO strongly encourages observers to begin following this star now, and to continue observations into October 2014 at least. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

  19. VizieR Online Data Catalog: AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)

    NASA Astrophysics Data System (ADS)

    Henden, A. A.; Templeton, M.; Terrell, D.; Smith, T. C.; Levine, S.; Welch, D.

    2016-01-01

    The AAVSO Photometric All Sky Survey (APASS) project is designed to bridge the gap between the shallow Tycho2 two-bandpass photometric catalog that is complete to V=11 and the deeper, but less spatially-complete catalogs like SDSS or PanSTARRS. It can be used for calibration of a specific field; for obtaining spectral information about single sources, determining reddening in a small area of the sky; or even obtaining current-epoch astrometry for rapidly moving objects. The survey is being performed at two locations: near Weed, New Mexico in the Northern Hemisphere; and at CTIO in the Southern Hemisphere. Each site consists of dual bore-sighted 20cm telescopes on a single mount, designed to obtain two bandpasses of information simultaneously. Each telescope covers 9 square degrees of sky with 2.5arcsec pixels, with the main survey taken with B,V,g',r',i' filters and covering the magnitude range 10Observers is responsible for the overall management of the survey; a team of professional astronomers participate in the data analysis. The project was initially funded by the Robert Martin Ayers Sciences Fund, with a follow-on grant from the National Science Foundation. (1 data file).

  20. The Shape of Long Outbursts in U Gem Type Dwarf Novae from AAVSO Data

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.

    2012-01-01

    We search the American Association of Variable Star Observers (AAVSO) archives of the two best studied dwarf novae in an attempt to find light curves for long out bursts that are extremely well-characterized. The systems are U Gem and S8 Cyg. Our goal is to search for embedded precursors such as those that have been found recently in the high fidelity Kepler data for superoutbursts of some members of the 8U UMa subclass of dwarf novae. For the vast majority of AAV80 data, the combination of low data cadence and large errors associated with individual measurements precludes one from making any strong statement about the shape of the long outbursts. However, for a small number of outbursts, extensive long term monitoring with digital photometry yields high fidelity light curves. We report the finding of embedded precursors in two of three candidate long outbursts. This reinforces van Paradijs' finding that long outbursts in dwarf novae above the period gap and superoutbursts in systems below the period gap constitute a unified class. The thermal-tidal instability to account for superoutbursts in the SU UMa stars predicts embedded precursors only for short orbital period dwarf novae, therefore the presence of embedded precursors in long orbital period systems - U Gem and SS Cyg - argues for a more general mechanism to explain long outbursts.

  1. Visual Working Memory for Observed Actions

    ERIC Educational Resources Information Center

    Wood, Justin N.

    2007-01-01

    Human society depends on the ability to remember the actions of other individuals, which is information that must be stored in a temporary buffer to guide behavior after actions have been observed. To date, however, the storage capacity, contents, and architecture of working memory for observed actions are unknown. In this article, the author…

  2. Bright Type-Ia Supernova PSN J09554214+6940260 and Observing Campaign

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.; Templeton, Matthew R.

    2014-01-01

    Announces the discovery of the SN 2014J = PSN J09554214+6940260 in M82 by Stephen J. Fossey (University College London Observatory) at magnitude 11.7 V on 2014 January 21.81 UT. Spectra by Cao et al. (Palomar Transient Factory Collaboration) show PSN J09554214+6940260 is a reddened young Type-Ia supernova discovered before maximum. They also report the best superfit match is SN2002bo at -14d, and that the supernova has a red continuum and deep Na D absorption. Both visual and CCD observations are encouraged. CCD observers are encouraged to perform filtered photometry, and if possible to transform their observations to the standard photometric system of their filters. In addition, rapid V-band time-series has been requested by Dr. Bradley Schaefer (Louisiana State University) for an exploratory search for possible flares or other short-term photometric variations during the outburst. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

  3. Anne S. Young: Professor and Variable Star Observer Extraordinaire

    NASA Astrophysics Data System (ADS)

    Bracher, Katherine

    2011-05-01

    Anne Sewell Young (1871-1961) was one of the eight original members of the AAVSO, to which she contributed more than 6500 observations over 33 years. She also taught astronomy for 37 years at Mount Holyoke College; among her students was Helen Sawyer Hogg. This paper will look at her life and career both at Mount Holyoke and with the AAVSO.

  4. Observations of Novae From ROAD

    NASA Astrophysics Data System (ADS)

    Hambsch, F.-J.

    2014-12-01

    The author discusses observations of galactic novae and some extragalactic supernovae from his remote observatory ROAD (Remote Observatory Atacama Desert) he commenced in August 2011 with Nova Lupi 2011 (PR Lup). The observed novae are mainly chosen according to AAVSO Alert Notices and AAVSO Special Notices as published on their website. Examples of dense observations of different novae are presented. The focus goes to the different behaviors of their light curves. It also demonstrates the capability of the remote observatory ROAD.

  5. VizieR Online Data Catalog: AAVSO International Variable Star Index VSX (Watson+, 2006-2014)

    NASA Astrophysics Data System (ADS)

    Watson, C.; Henden, A. A.; Price, A.

    2016-10-01

    This file contains Galactic stars known or suspected to be variable. It lists all stars that have an entry in the AAVSO International Variable Star Index (VSX; http://www.aavso.org/vsx). The database consisted initially of the General Catalogue of Variable Stars (GCVS) and the New Catalogue of Suspected Variables (NSV) and was then supplemented with a large number of variable star catalogues, as well as individual variable star discoveries or variables found in the literature. Effort has also been invested to update the entries with the latest information regarding position, type and period and to remove duplicates. The VSX database is being continually updated and maintained. For historical reasons some objects outside of the Galaxy have been included. (3 data files).

  6. Adaptive tuning functions arise from visual observation of past movement

    PubMed Central

    Howard, Ian S.; Franklin, David W.

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  7. Adaptive tuning functions arise from visual observation of past movement.

    PubMed

    Howard, Ian S; Franklin, David W

    2016-01-01

    Visual observation of movement plays a key role in action. For example, tennis players have little time to react to the ball, but still need to prepare the appropriate stroke. Therefore, it might be useful to use visual information about the ball trajectory to recall a specific motor memory. Past visual observation of movement (as well as passive and active arm movement) affects the learning and recall of motor memories. Moreover, when passive or active, these past contextual movements exhibit generalization (or tuning) across movement directions. Here we extend this work, examining whether visual motion also exhibits similar generalization across movement directions and whether such generalization functions can explain patterns of interference. Both the adaptation movement and contextual movement exhibited generalization beyond the training direction, with the visual contextual motion exhibiting much broader tuning. A second experiment demonstrated that this pattern was consistent with the results of an interference experiment where opposing force fields were associated with two separate visual movements. Overall, our study shows that visual contextual motion exhibits much broader (and shallower) tuning functions than previously seen for either passive or active movements, demonstrating that the tuning characteristics of past motion are highly dependent on their sensory modality. PMID:27341163

  8. New Photometric Observations and the 2015 Eclipse of the Symbiotic Nova Candidate ASAS J174600-2321.3

    NASA Astrophysics Data System (ADS)

    Hambsch, F.-J.; Hümmerich, S.; Bernhard, K.; Otero, S.

    2015-12-01

    The eclipsing binary system ASAS J174600-2321.3, which has shown a conspicuous brightening of ~4 magnitudes (V) in the past, was recently identified as a symbiotic nova candidate. A long-term photometric monitoring program was initiated in July 2014. In its present active stage, the system shows deep eclipses with an amplitude of ~3.5 magnitudes (V) that occur about every 33 months. In order to monitor the eclipse of 2015, AAVSO Alert Notice 510 was issued. During the ensuing campaign, AAVSO observers obtained 338 measurements in Johnson B, 393 measurements in Johnson V, and 369 measurements in Cousins I, as well as 27 visual observations. The present paper presents and analyzes these data from the AAVSO International Database, along with observations from the aforementioned photometric monitoring program. From these data, we were able to refine the orbital period to Porb = 1012.4 days. Furthermore, the data are suggestive of a slight decrease in mean brightness, which—if proven real—might indicate a decline of the outburst.

  9. An Ideal Observer Analysis of Visual Working Memory

    ERIC Educational Resources Information Center

    Sims, Chris R.; Jacobs, Robert A.; Knill, David C.

    2012-01-01

    Limits in visual working memory (VWM) strongly constrain human performance across many tasks. However, the nature of these limits is not well understood. In this article we develop an ideal observer analysis of human VWM by deriving the expected behavior of an optimally performing but limited-capacity memory system. This analysis is framed around…

  10. Interactive versus Observational Learning of Spatial Visualization of Geometric Transformat

    ERIC Educational Resources Information Center

    Smith, Glenn Gordon; Middleton, James A.

    2003-01-01

    This study compared interaction with a computer vs. observation as learning situations for low and high ability student's learning of spatial visualization and geometric transformations. Thirty-two fifth grade boys took the Differential Aptitude Test, Space Relations Subset (DAT), and then participated in the experiment. Pre-test and post-test…

  11. Basic visual observation skills training course: Appendix A. Final report

    SciTech Connect

    Toquam, J.L.; Morris, F.A.; Griggs, J.R.

    1995-06-01

    The purpose of the basic visual observation skills course is to help safeguards inspectors evaluate and improve their skills in making observations during inspections and in evaluating and interpreting this information. The first 12 hours of the course provide training in five skill areas: perception and recognition; attention to detail; memory; mental imaging, mapping, and modeling skills; and judgment and decision making. Following this training is an integrating exercise involving a simulated safeguards inspection. This report contains the course manual and materials.

  12. Introducing Solar Observation to Elementary Students

    NASA Astrophysics Data System (ADS)

    Dyck, G. P.

    2013-06-01

    (Abstract only) I will demonstrate the presentation I have developed for introducing solar observation to elementary students in Dartmouth, Massachusetts, and surrounding public schools. Copies of my program will be available for AAVSO members who would like to use it.

  13. Telescopic observations - Visual, photographic, polarimetric. [of planet Mars

    NASA Technical Reports Server (NTRS)

    Martin, Leonard J.; James, Philip B.; Dollfus, Audouin; Iwasaki, Kyosuke; Beish, Jeffrey D.

    1992-01-01

    The paper divides the high points of telescopic observations of Mars into three time periods: historical, missions support (recent), and present. Particular attention is given to visual and photographic observations, with brief discussions of spectroscopic and polarization studies. Major topics of Martian phenomena included are albedo features, polar caps, dust storms, and white clouds. The interannual variability of the recessions of seasonal polar caps has been compared to dust storm activity, but this relationship remains uncertain. Only a very limited number of canals can be related to markings on the Viking images. The remainder are argued to be optical illusions created by observers pushing their perceived resolution beyond practical limits.

  14. Fermi-LAT Gamma-ray Observations of Nova Lupus 2016 (ASASSN-16kt)

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Jean, P.; Shore, S. N.; Fermi Large Area Telescope Collaboration

    2016-10-01

    The Fermi Gamma-ray Space Telescope performed a ~6-day Target of Opportunity (ToO) observation of Nova Lupus 2016 (ATel #9538, #9539, CBET #4322) that commenced on September 28. Considering earlier all-sky survey Large Area Telescope (LAT) observations as well, preliminary analysis indicates gamma-ray emission at ~2 sigma was detected around 1 to 2 days after the optical peak on September 25th (pre-validated AAVSO visual lightcurve; ATel #9550, CBET #4322) when the optical spectra show opaque ejecta, similar to previous gamma-ray detected novae (Fermi-LAT collaboration, 2014 Science 345, 554; Cheung et al. 2016 ApJ 826, 142).

  15. Basic visual observation skills training course: Appendix B. Final report

    SciTech Connect

    Toquam, J.L.; Morris, F.A.; Griggs, J.R.

    1995-06-01

    The purpose of the basic visual observation skills course is to help safeguards inspectors evaluate and improve their skills in making observations during inspections and in evaluating and interpreting this information. The first 12 hours of the course provide training in five skill areas: perception and recognition; attention to detail; memory; mental imaging, mapping, and modeling skills; and judgment and decision making. Following this training is an integrating exercise involving a simulated safeguards inspection. This report contains the in-class exercises in the five skill areas; pre- and post-course exercises in closure, hidden figures, map memory, and mental rotations; the final examination; a training evaluation form; and the integrating exercise.

  16. Visual Target Tracking in the Presence of Unknown Observer Motion

    NASA Technical Reports Server (NTRS)

    Williams, Stephen; Lu, Thomas

    2009-01-01

    Much attention has been given to the visual tracking problem due to its obvious uses in military surveillance. However, visual tracking is complicated by the presence of motion of the observer in addition to the target motion, especially when the image changes caused by the observer motion are large compared to those caused by the target motion. Techniques for estimating the motion of the observer based on image registration techniques and Kalman filtering are presented and simulated. With the effects of the observer motion removed, an additional phase is implemented to track individual targets. This tracking method is demonstrated on an image stream from a buoy-mounted or periscope-mounted camera, where large inter-frame displacements are present due to the wave action on the camera. This system has been shown to be effective at tracking and predicting the global position of a planar vehicle (boat) being observed from a single, out-of-plane camera. Finally, the tracking system has been extended to a multi-target scenario.

  17. Efficient visual-search model observers for PET

    PubMed Central

    2014-01-01

    Objective: Scanning model observers have been efficiently applied as a research tool to predict human-observer performance in F-18 positron emission tomography (PET). We investigated whether a visual-search (VS) observer could provide more reliable predictions with comparable efficiency. Methods: Simulated two-dimensional images of a digital phantom featuring tumours in the liver, lungs and background soft tissue were prepared in coronal, sagittal and transverse display formats. A localization receiver operating characteristic (LROC) study quantified tumour detectability as a function of organ and format for two human observers, a channelized non-prewhitening (CNPW) scanning observer and two versions of a basic VS observer. The VS observers compared watershed (WS) and gradient-based search processes that identified focal uptake points for subsequent analysis with the CNPW observer. The model observers treated “background-known-exactly” (BKE) and “background-assumed-homogeneous” assumptions, either searching the entire organ of interest (Task A) or a reduced area that helped limit false positives (Task B). Performance was indicated by area under the LROC curve. Concordance in the localizations between observers was also analysed. Results: With the BKE assumption, both VS observers demonstrated consistent Pearson correlation with humans (Task A: 0.92 and Task B: 0.93) compared with the scanning observer (Task A: 0.77 and Task B: 0.92). The WS VS observer read 624 study test images in 2.0 min. The scanning observer required 0.7 min. Conclusion: Computationally efficient VS can enhance the stability of statistical model observers with regard to uncertainties in PET tumour detection tasks. Advances in knowledge: VS models improve concordance with human observers. PMID:24837105

  18. AH Her Observing Campaign

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-05-01

    Dr. Juan Echevarria (Universidad Nacional Autónoma de México) and colleagues request AAVSO assistance in a campaign on the Z Cam-type cataclysmic variable AH Her being carried out 2013 May 29 - June 18. They will be making photometric and spectroscopic observations of AH Her using the 2.1m and 0.84m telescopes at San Pedro Martir Observatory (SPM). Their goal is to carry out a radial velocity study of the system components using modern detectors; no study of AH Her has been made since the one by Horne, Wade, and Szkody in 1980-1981 (1986MNRAS.219..791H). Photometry and spectroscopy are requested. AH Her, for decades a reasonably "regular" Z Cam system, began exhibiting significantly anomalous behavior in ~2007. Since then it has experienced brief periods of fairly typical behavior interspersed with more anomalous intervals, including some unprecedented behavior. Most recently, it has returned to a more normal pattern of outbursts shape-wise but it is not back to its normal amplitude or frequency. AAVSO data will be essential for correlation in order to determine the precise time(s) of minimum occurring during the campaign. Finder charts with sequences may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  19. 3D Orbit Visualization for Earth-Observing Missions

    NASA Technical Reports Server (NTRS)

    Jacob, Joseph C.; Plesea, Lucian; Chafin, Brian G.; Weiss, Barry H.

    2011-01-01

    This software visualizes orbit paths for the Orbiting Carbon Observatory (OCO), but was designed to be general and applicable to any Earth-observing mission. The software uses the Google Earth user interface to provide a visual mechanism to explore spacecraft orbit paths, ground footprint locations, and local cloud cover conditions. In addition, a drill-down capability allows for users to point and click on a particular observation frame to pop up ancillary information such as data product filenames and directory paths, latitude, longitude, time stamp, column-average dry air mole fraction of carbon dioxide, and solar zenith angle. This software can be integrated with the ground data system for any Earth-observing mission to automatically generate daily orbit path data products in Google Earth KML format. These KML data products can be directly loaded into the Google Earth application for interactive 3D visualization of the orbit paths for each mission day. Each time the application runs, the daily orbit paths are encapsulated in a KML file for each mission day since the last time the application ran. Alternatively, the daily KML for a specified mission day may be generated. The application automatically extracts the spacecraft position and ground footprint geometry as a function of time from a daily Level 1B data product created and archived by the mission s ground data system software. In addition, ancillary data, such as the column-averaged dry air mole fraction of carbon dioxide and solar zenith angle, are automatically extracted from a Level 2 mission data product. Zoom, pan, and rotate capability are provided through the standard Google Earth interface. Cloud cover is indicated with an image layer from the MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the Aqua satellite, which is automatically retrieved from JPL s OnEarth Web service.

  20. Visual Observations of Mixing Quality in a Prototype Canyon Tank

    SciTech Connect

    Hassan, N.M.

    1995-03-07

    A series of mixing tests were performed to identify the range of liquid levels and overall dispersed (organic) concentrations where a constant agitator speed representative of plant operations could eliminate a separate organic layer on the liquid surface. The test runs were made in a transparent, baffled, paddle-agitated, Plexiglas vessel which was fitted with three concentric cooling coils. A visual observation method was used without taking any samples to determine the quality of mixing in the agitated vessel as a function of the total liquid level in the vessel at a given dispersed phase concentration (8 vol %) and various organic phase concentrations at a constant water content. The observations have determined that gross uniform dispersion throughout a canyon tank can be achieved with the current plant impeller speed when the total liquid level is near the vicinity of the second (top) impeller. These observations were recorded in a video tape.

  1. Visual-search observers for SPECT simulations with clinical backgrounds

    NASA Astrophysics Data System (ADS)

    Gifford, Howard C.

    2016-03-01

    The purpose of this work was to test the ability of visual-search (VS) model observers to predict the lesion- detection performance of human observers with hybrid SPECT images. These images consist of clinical back- grounds with simulated abnormalities. The application of existing scanning model observers to hybrid images is complicated by the need for extensive statistical information, whereas VS models based on separate search and analysis processes may operate with reduced knowledge. A localization ROC (LROC) study involved the detection and localization of solitary pulmonary nodules in Tc-99m lung images. The study was aimed at op- timizing the number of iterations and the postfiltering of four rescaled block-iterative reconstruction strategies. These strategies implemented different combinations of attenuation correction, scatter correction, and detector resolution correction. For a VS observer in this study, the search and analysis processes were guided by a single set of base morphological features derived from knowledge of the lesion profile. One base set used difference-of- Gaussian channels while a second base set implemented spatial derivatives in combination with the Burgess eye filter. A feature-adaptive VS observer selected features of interest for a given image set on the basis of training-set performance. A comparison of the feature-adaptive observer results against previously acquired human-observer data is presented.

  2. Formal Art Observation Training Improves Medical Students’ Visual Diagnostic Skills

    PubMed Central

    Naghshineh, Sheila; Hafler, Janet P.; Miller, Alexa R.; Blanco, Maria A.; Lipsitz, Stuart R.; Dubroff, Rachel P.; Khoshbin, Shahram

    2008-01-01

    Background Despite evidence of inadequate physical examination skills among medical students, teaching these skills has declined. One method of enhancing inspection skills is teaching “visual literacy,” the ability to reason physiology and pathophysiology from careful and unbiased observation. Objective To improve students’ visual acumen through structured observation of artworks, understanding of fine arts concepts and applying these skills to patient care. Design Prospective, partially randomized pre- vs. post-course evaluation using mixed-methods data analysis. Participants Twenty-four pre-clinical student participants were compared to 34 classmates at a similar stage of training. Intervention Training the Eye: Improving the Art of Physical Diagnosis consists of eight paired sessions of art observation exercises with didactics that integrate fine arts concepts with physical diagnosis topics and an elective life drawing session. Measurements The frequency of accurate observations on a 1-h visual skills examination was used to evaluate pre- vs. post-course descriptions of patient photographs and art imagery. Content analysis was used to identify thematic categories. All assessments were blinded to study group and pre- vs. post-course evaluation. Results Following the course, class participants increased their total mean number of observations compared to controls (5.41 ± 0.63 vs. 0.36 ± 0.53, p < 0.0001) and had increased sophistication in their descriptions of artistic and clinical imagery. A ‘dose-response’ was found for those who attended eight or more sessions, compared to participants who attended seven or fewer sessions (6.31 + 0.81 and 2.76 + 1.2, respectively, p = 0.03). Conclusions This interdisciplinary course improved participants’ capacity to make accurate observations of art and physical findings. Electronic supplementary material The online version of this article (doi:10.1007/s11606-008-0667-0) contains

  3. Cataclysmic variables to be monitored for HST observations

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2012-09-01

    Drs. Boris Gaensicke (Warwick University), Joseph Patterson (Columbia University, Center for Backyard Astrophysics), and Arne Henden (AAVSO), on behalf of a consortium of 16 astronomers, requested the help of AAVSO observers in monitoring the ~40 cataclysmic variables in support of Hubble Space Telescope observations in the coming months. The HST COS (Cosmic Origins Spectrograph) will be carrying out far-ultraviolet spectroscopy of ~40 CVs sequentially, with the aim to measure the temperatures, atmospheric compositions, rotation rates, and eventually masses of their white dwarfs. The primary purpose of the monitoring is to know whether each target is in quiescence immediately prior to the observation window; if it is in outburst it will be too bright for the HST instrumentation. Based on the information supplied by the AAVSO, the HST scheduling team will make the decision (usually) the evening before the scheduled observing time as to whether to go forward with the HST observations. For CCD observers, simultaneous photometry [shortly before, during, and after the HST observations] would be ideal. B filter would be best for a light curve, although for the magnitude estimates, V would be best. Finder charts may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. If the target is seen in outburst, please contact the AAVSO immediately and post a message to the Observations and Campaigns & Observations Reports forum (http://www.aavso.org/forum). This campaign will run the better part of a year or longer. See full Alert Notice for more details and list of objects.

  4. Basic visual observation skills training course. Final report

    SciTech Connect

    Toquam, J.L.; Morris, F.A.; Griggs, J.R.

    1995-06-01

    This is the third report in a series prepared to assist the International Atomic Energy Agency (IAEA or Agency) in enhancing the effectiveness of its international safeguards inspections through inspector training in Observation Skills. The first report (Phase 1) was essentially exploratory. It defined Observation Skills` broadly to include all appropriate cognitive, communications, and interpersonal techniques that have the potential to help IAEA safeguards inspectors function more effectively. The second report (Phase 2) provided a more specific basis for the actual design and delivery of Observation Skills training to IAEA inspectors. The present report (Phase 3) documents the design of a Basic Visual Observation Skills course and delivery of the course to safeguards inspectors at IAEA Headquarters Vienna in February and May of 1995. The purpose of the course is to help safeguards inspectors evaluate and improve their skills in making observations during inspections and in evaluating and interpreting this information. The course is basic in the sense that it provides training in skills which are generally applicable to inspections of all types of facilities and activities subject to safeguards. The course is designed for 16 hours of classroom delivery, ideally in four 4-hour sessions over a period of four days. The first 12 hours provide training in five skill areas: perception and recognition; attention and attention to detail; memory; mental imaging, mapping, and modeling skills; and judgment and decision making. Following the training in each of the five skill areas is an Integrating Exercise involving a simulated safeguards inspection.

  5. Conveying Clinical Reasoning Based on Visual Observation via Eye-Movement Modelling Examples

    ERIC Educational Resources Information Center

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nystrom, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Complex perceptual tasks, like clinical reasoning based on visual observations of patients, require not only conceptual knowledge about diagnostic classes but also the skills to visually search for symptoms and interpret these observations. However, medical education so far has focused very little on how visual observation skills can be…

  6. Anne S. Young: Professor and Variable Star Observer Extraordinaire

    NASA Astrophysics Data System (ADS)

    Bracher, K.

    2012-06-01

    One of the original eight members of the AAVSO, but not well known today, was Professor Anne Sewell Young of Mount Holyoke College. Miss Young taught there for thirty-seven years, and trained many women astronomers during the first third of the 20th century. This paper will attempt to present her life as an inspiring teacher, as well as a contributor of more than 6,500 variable star observations to the AAVSO.

  7. Observations on the Habilitation of Children with Cortical Visual Impairment.

    ERIC Educational Resources Information Center

    Groenveld, M.; And Others

    1990-01-01

    This article discusses the increasing incidence of cortical visual impairments, resulting from medical advancements making possible the survival of critically ill children with severe brain damage. Discussed are the prevalence of multiple handicaps, formation of visual concepts, foreground/background distinction, potential for mainstreaming, use…

  8. Visions of visualization aids - Design philosophy and observations

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.

    1989-01-01

    Aids for the visualization of high-dimensional scientific or other data must be designed. Simply casting multidimensional data into a two-dimensional or three-dimensional spatial metaphor does not guarantee that the presentation will provide insight or a parsimonious description of phenomena implicit in the data. Useful visualization, in contrast to glitzy, high-tech, computer-graphics imagery, is generally based on preexisting theoretical beliefs concerning the underlying phenomena. These beliefs guide selection and formatting of the plotted variables. Visualization tools are useful for understanding naturally three-dimensional data bases such as those used by pilots or astronauts. Two examples of such aids for spatial maneuvering illustrate that informative geometric distortion may be introduced to assist visualization and that visualization of complex dynamics alone may not be adequate to provide the necessary insight into the underlying processes.

  9. Request for observations of GW Lib and V842 Cen in support of HST observations

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2010-03-01

    Dr. Paula Szkody (U. Washington) has requested the help of AAVSO observers to provide monitoring of the cataclysmic variables GW Lib and V842 Cen in support of Hubble Space Telescope observations in March 2010. Observations of both objects are requested beginning immediately, with intensive observations requested beginning 48 hours prior to the scheduled HST visit. The first observation of GW Lib has now been scheduled for 2010 March 11 03:45 UT; intensive observations by the AAVSO community are requested beginning 2010 March 9 UT. Observations of V842 Cen are expected to be scheduled during the dates of 2010 March 18-22. Observations of both sources are requested to guarantee to ground controllers at STScI that they are below V~14.0 which is considered the safe limit for the Cosmic Origins Spectrograph. Positive observations are preferred if at all possible, however any fainter-than below V=14 is useful. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  10. How Do Observer's Responses Affect Visual Long-Term Memory?

    ERIC Educational Resources Information Center

    Makovski, Tal; Jiang, Yuhong V.; Swallow, Khena M.

    2013-01-01

    How does responding to an object affect explicit memory for visual information? The close theoretical relationship between action and perception suggests that items that require a response should be better remembered than items that require no response. However, conclusive evidence for this claim is lacking, as semantic coherence, category size,…

  11. Radical "visual capture" observed in a patient with severe visual agnosia.

    PubMed

    Takaiwa, Akiko; Yoshimura, Hirokazu; Abe, Hirofumi; Terai, Satoshi

    2003-01-01

    We report the case of a 79-year-old female with visual agnosia due to brain infarction in the left posterior cerebral artery. She could recognize objects used in daily life rather well by touch (the number of objects correctly identified was 16 out of 20 presented objects), but she could not recognize them as well by vision (6 out of 20). In this case, it was expected that she would recognize them well when permitted to use touch and vision simultaneously. Our patient, however, performed poorly, producing 5 correct answers out of 20 in the Vision-and-Touch condition. It would be natural to think that visual capture functions when vision and touch provide contradictory information on concrete positions and shapes. However, in the present case, it functioned in spite of the visual deficit in recognizing objects. This should be called radical visual capture. By presenting detailed descriptions of her symptoms and neuropsychological and neuroradiological data, we clarify the characteristics of this type of capture.

  12. Skylab simulator visual displays and training for joint observing programs.

    PubMed

    Holt, A C; da Silva, A J

    1977-04-01

    The complexity of the Skylab Apollo Telescope Mount (ATM) experiment operations necessitated the use of high fidelity simulations of the onboard visual displays and pointing system for crew training. The displays which were simulated included the H-alpha displays, XUV monitor display, XUV/slit/white light display, x-ray image display, and the white light coronagraph display. The pointing simulation was achieved by projecting film sequences which were subsequently viewed by TV cameras. An optical system in front of the vidicons simulated the pointing, roll, and zoom capabilities of the ATM and sensing systems. The simulation enabled the Skylab crewmen to obtain valuable integrated training combining such tasks as target recognition and status assessment, complex and the time dependent pointing operations, malfunction analyses, and rapid responses to flare and other transient events.

  13. Setup for Visual Observation of Carbon-Nanotube Arc Process

    NASA Technical Reports Server (NTRS)

    Scott, Carl D.; Arepalli, Sivaram

    2004-01-01

    A simple optical setup has been devised to enable safe viewing of the arc and measurement of the interelectrode gap in a process in which carbon nanotubes are produced in an arc between a catalyst-filled carbon anode and a graphite cathode. This setup can be used for visually guided manual positioning of the anode to maintain the interelectrode gap at a desired constant value, possibly as a low-technology alternative to the automatic position/voltage control described in Automatic Control of Arc Process for Making Carbon Nanotubes (MSC-23134), NASA Tech Briefs, Vol. 28, No. 3 (March 2004), page 51. The optical setup consists mainly of lenses for projecting an image of the arc onto a wall, plus a calibrated grid that is mounted on the wall so that one can measure the superimposed image of the arc. To facilitate determination of the end point of the process, the anode is notched, by use of a file, at the end of the filled portion that is meant to be consumed in the process. As the anode is consumed and the notch comes into view in the scene projected onto the wall, the process operator switches off the arc current.

  14. Meteor Shower observations from the Indian Sub-Continent (Visual Photographic and Radio)

    NASA Astrophysics Data System (ADS)

    Dabhade, R.; Savant, V.; Belapure, J.

    2011-01-01

    We review the present status of meteor shower observing from the Indian sub-continent. Some amateur groups are active in visual observations, although they are restricted by the lack of good observing sites. Ham radio appears to be promising as a technique to monitor the major meteor showers in this region. We present radio observations of the 2006 Quadrantids.

  15. Impaired Visual Integration in Children with Traumatic Brain Injury: An Observational Study

    PubMed Central

    Weeda, Wouter D.; van Heurn, L. W. Ernest; Vermeulen, R. Jeroen; Goslings, J. Carel; Luitse, Jan S. K.; Poll-Thé, Bwee Tien; Beelen, Anita; van der Wees, Marleen; Kemps, Rachèl J. J. K.; Catsman-Berrevoets, Coriene E.

    2015-01-01

    Background Axonal injury after traumatic brain injury (TBI) may cause impaired sensory integration. We aim to determine the effects of childhood TBI on visual integration in relation to general neurocognitive functioning. Methods We compared children aged 6–13 diagnosed with TBI (n = 103; M = 1.7 years post-injury) to children with traumatic control (TC) injury (n = 44). Three TBI severity groups were distinguished: mild TBI without risk factors for complicated TBI (mildRF- TBI, n = 22), mild TBI with ≥1 risk factor (mildRF+ TBI, n = 46) or moderate/severe TBI (n = 35). An experimental paradigm measured speed and accuracy of goal-directed behavior depending on: (1) visual identification; (2) visual localization; or (3) both, measuring visual integration. Group-differences on reaction time (RT) or accuracy were tracked down to task strategy, visual processing efficiency and extra-decisional processes (e.g. response execution) using diffusion model analysis. General neurocognitive functioning was measured by a Wechsler Intelligence Scale short form. Results The TBI group had poorer accuracy of visual identification and visual integration than the TC group (Ps ≤ .03; ds ≤ -0.40). Analyses differentiating TBI severity revealed that visual identification accuracy was impaired in the moderate/severe TBI group (P = .05, d = -0.50) and that visual integration accuracy was impaired in the mildRF+ TBI group and moderate/severe TBI group (Ps < .02, ds ≤ -0.56). Diffusion model analyses tracked impaired visual integration accuracy down to lower visual integration efficiency in the mildRF+ TBI group and moderate/severe TBI group (Ps < .001, ds ≤ -0.73). Importantly, intelligence impairments observed in the TBI group (P = .009, d = -0.48) were statistically explained by visual integration efficiency (P = .002). Conclusions Children with mildRF+ TBI or moderate/severe TBI have impaired visual integration efficiency, which may contribute to poorer general

  16. Some 2015 Measurements of Wide and Faint Double Stars Compared with Visual Observations

    NASA Astrophysics Data System (ADS)

    Knapp, Wilfried

    2016-07-01

    A backlog of astrometry and photometry measurements made in 2015 for comparison with visual observations is reported here with the intention of providing recent precise measurements for the given objects.

  17. Retinex Image Processing: Improved Fidelity To Direct Visual Observation

    NASA Technical Reports Server (NTRS)

    Jobson, Daniel J.; Rahman, Zia-Ur; Woodell, Glenn A.

    1996-01-01

    Recorded color images differ from direct human viewing by the lack of dynamic range compression and color constancy. Research is summarized which develops the center/surround retinex concept originated by Edwin Land through a single scale design to a multi-scale design with color restoration (MSRCR). The MSRCR synthesizes dynamic range compression, color constancy, and color rendition and, thereby, approaches fidelity to direct observation.

  18. Observers' cognitive states modulate how visual inputs relate to gaze control.

    PubMed

    Kardan, Omid; Henderson, John M; Yourganov, Grigori; Berman, Marc G

    2016-09-01

    Previous research has shown that eye-movements change depending on both the visual features of our environment, and the viewer's top-down knowledge. One important question that is unclear is the degree to which the visual goals of the viewer modulate how visual features of scenes guide eye-movements. Here, we propose a systematic framework to investigate this question. In our study, participants performed 3 different visual tasks on 135 scenes: search, memorization, and aesthetic judgment, while their eye-movements were tracked. Canonical correlation analyses showed that eye-movements were reliably more related to low-level visual features at fixations during the visual search task compared to the aesthetic judgment and scene memorization tasks. Different visual features also had different relevance to eye-movements between tasks. This modulation of the relationship between visual features and eye-movements by task was also demonstrated with classification analyses, where classifiers were trained to predict the viewing task based on eye movements and visual features at fixations. Feature loadings showed that the visual features at fixations could signal task differences independent of temporal and spatial properties of eye-movements. When classifying across participants, edge density and saliency at fixations were as important as eye-movements in the successful prediction of task, with entropy and hue also being significant, but with smaller effect sizes. When classifying within participants, brightness and saturation were also significant contributors. Canonical correlation and classification results, together with a test of moderation versus mediation, suggest that the cognitive state of the observer moderates the relationship between stimulus-driven visual features and eye-movements. (PsycINFO Database Record PMID:27123677

  19. Happy with a difference, unhappy with an identity: observers' mood determines processing depth in visual search.

    PubMed

    Grubert, Anna; Schmid, Petra; Krummenacher, Joseph

    2013-01-01

    Visual search for feature targets was employed to investigate whether the mechanisms underlying visual selective attention are modulated by observers' mood. The effects of induced mood on overall mean reaction times and on changes and repetitions of target-defining features and dimensions across consecutive trials were measured. The results showed that reaction times were significantly slower in the negative than in the positive and neutral mood groups. Furthermore, the results demonstrated that the processing stage that is activated to select visual information in a feature search task is modulated by the observer's mood. In participants with positive or neutral moods, dimension-specific, but no feature-specific, intertrial transition effects were found, suggesting that these observers based their responses on a salience signal coding the most conspicuous display location. Conversely, intertrial effects in observers in a negative mood were feature-specific in nature, suggesting that these participants accessed the feature identity level before responding. PMID:23079893

  20. Analysis of ocean in situ observations and web-based visualization

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Watelet, Sylvain; Troupin, Charles; Alvera Azcarate, Aida; Santinelli, Giorgio; Hendriksen, Gerrit; Giorgetti, Alessandra; Beckers, Jean-Marie

    2016-04-01

    The sparsity of observations poses a challenge common to various ocean science disciplines. Even for physical parameters where the spatial and temporal coverage is higher, current observational networks undersample a broad spectrum of scales. The situation is generally more severe for chemical and biological parameters because related sensors are less widely deployed. The analysis tool DIVA (Data-Interpolating Variational Analysis) is designed to generate gridded fields from in situ observations. DIVA has been applied to various physical (temperature and salinity), chemical (concentration of nitrate, nitrite and phosphate) and biological parameters (abundance of a species) in the context of different European projects (SeaDataNet, EMODnet Chemistry and EMODnet Biology). We show the technologies used to visualize the gridded fields based on the Web Map Services standard. Visualization of analyses from in situ observations provides a unique set of challenges since the accuracy of the analysed field is not spatially uniform as it strongly depends on the observations location. In addition, an adequate handling of depth and time dimensions is essential. Beside visualizing the gridded fields, access is also given to the underlying observations. It is thus also possible to view more detailed information about the variability of the observations. The in situ observation visualization service allows one to display vertical profiles and time series and it is built upon OGC standards (the Web Feature Service and Web Processing Services) and following recommendation from the INSPIRE directive.

  1. Using Participant-Observation to Determine the Social Behavior of Visually Handicapped Children.

    ERIC Educational Resources Information Center

    Smith, Tom E. C.; Smith, Bonnie L.

    1983-01-01

    Participant-observation was used to evaluate the social behavior of 20 visually handicapped juniors and seniors in a residential school for the blind. Analysis revealed that the behavior observed was fairly typical of social behavior expected by sighted adolescents in any school setting. (Author/SW)

  2. Task-dependent calibration of auditory spatial perception through environmental visual observation.

    PubMed

    Tonelli, Alessia; Brayda, Luca; Gori, Monica

    2015-01-01

    Visual information is paramount to space perception. Vision influences auditory space estimation. Many studies show that simultaneous visual and auditory cues improve precision of the final multisensory estimate. However, the amount or the temporal extent of visual information, that is sufficient to influence auditory perception, is still unknown. It is therefore interesting to know if vision can improve auditory precision through a short-term environmental observation preceding the audio task and whether this influence is task-specific or environment-specific or both. To test these issues we investigate possible improvements of acoustic precision with sighted blindfolded participants in two audio tasks [minimum audible angle (MAA) and space bisection] and two acoustically different environments (normal room and anechoic room). With respect to a baseline of auditory precision, we found an improvement of precision in the space bisection task but not in the MAA after the observation of a normal room. No improvement was found when performing the same task in an anechoic chamber. In addition, no difference was found between a condition of short environment observation and a condition of full vision during the whole experimental session. Our results suggest that even short-term environmental observation can calibrate auditory spatial performance. They also suggest that echoes can be the cue that underpins visual calibration. Echoes may mediate the transfer of information from the visual to the auditory system. PMID:26082692

  3. Best Visual Presentation--Observations from the Award Committee. IR Applications. Volume 4

    ERIC Educational Resources Information Center

    Bers, Trudy

    2005-01-01

    In 2003, the Association for Institutional Research (AIR) initiated the Best Visual Presentation (BVP) award to acknowledge the contributions made through new ways of professional communication, in addition to those made through more traditional scholarly formats. The purpose of this "IR Applications" is to provide observations from the BVP Award…

  4. Visual Observation of Dissolution of Copper Ions from a Copper Electrode

    ERIC Educational Resources Information Center

    Ikemoto, Isao; Saitou, Kouichi

    2013-01-01

    During electrolysis, to visually observe the conversion of a metal to its cation, either the cation or its complex ion should have a distinct color while the electrolyte solution must be colorless and transparent. A demonstration is described in which copper is used as the electrodes and sodium polyacrylate (a superabsorbent polymer) solution is…

  5. VISUALLY OBSERVED MOLD AND MOLDY ODOR VERSUS QUANTITATIVELY MEASURED MICROBIAL EXPOSURE IN HOMES

    EPA Science Inventory

    The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children's asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child's age 1 (Year ...

  6. The Early Development of Object Knowledge: A Study of Infants' Visual Anticipations during Action Observation

    ERIC Educational Resources Information Center

    Hunnius, Sabine; Bekkering, Harold

    2010-01-01

    This study examined the developing object knowledge of infants through their visual anticipation of action targets during action observation. Infants (6, 8, 12, 14, and 16 months) and adults watched short movies of a person using 3 different everyday objects. Participants were presented with objects being brought either to a correct or to an…

  7. Estrus detection using radiotelemetry or visual observation and tail painting for dairy cows on pasture.

    PubMed

    Xu, Z Z; McKnight, D J; Vishwanath, R; Pitt, C J; Burton, L J

    1998-11-01

    The efficiency and accuracy of estrus detection using HeatWatch (DDx Inc., Denver, CO) or visual observation were compared in an autumn-calving Friesian herd (n = 48 per group) and a spring-calving Jersey herd (n = 50 per group) grazing on pasture. Cows in the group monitored by the HeatWatch system were fitted with a pressure-sensitive transmitter that signaled mounting activities associated with estrus. Visual observation was carried out for about 20 min before the morning and afternoon milkings and was aided by a strip of paint applied over the tailhead. Ovarian cyclicity was monitored with progesterone concentrations in milk samples collected twice a week. The efficiency and accuracy of estrus detection were, respectively, 98.4 and 97.6% for visual observation and 91.7 and 100% for HeatWatch detection. Autumn-calving herds differed from spring-calving herds in duration of estrus (9.7 vs. 7.3 h), number of mounts (13.6 vs. 8.5), total duration of mounts (36.8 vs. 19.9 s), and mean duration of a mount (2.6 vs. 2.3 s). There was no significant variation in the distribution of the time of onset of estrus or mounting activities at different hours of the day. Conception rate was similar for AI after estrus detection with HeatWatch (65.8%) or after visual observation (65.0%). The highest conception rate was obtained when AI was carried out between 12 and 18 h after the first mount. Both the HeatWatch system and visual observation plus tail painting can be used for estrus detection of dairy cows on pasture.

  8. Observations of Novae from ROAD

    NASA Astrophysics Data System (ADS)

    Hambsch, Franz-Josef

    2014-05-01

    The author discusses observations of galactic novae and some extragalactic supernovae from his remote observatory ROAD (Remote Observatory Atacama Desert) he commenced in August 2011 with Nova Lupi 2011 (PR Lup). The observed novae are mainly chosen according to alert notices and special notices of the AAVSO as published on their website. Examples of dense observations of different novae are presented. The focus goes to the different behaviors of their light curves. It also demonstrates the capability of the remote observatory ROAD.

  9. MATISSE a web-based tool to access, visualize and analyze high resolution minor bodies observation

    NASA Astrophysics Data System (ADS)

    Zinzi, Angelo; Capria, Maria Teresa; Palomba, Ernesto; Antonelli, Lucio Angelo; Giommi, Paolo

    2016-07-01

    In the recent years planetary exploration missions acquired data from minor bodies (i.e., dwarf planets, asteroid and comets) at a detail level never reached before. Since these objects often present very irregular shapes (as in the case of the comet 67P Churyumov-Gerasimenko target of the ESA Rosetta mission) "classical" bidimensional projections of observations are difficult to understand. With the aim of providing the scientific community a tool to access, visualize and analyze data in a new way, ASI Science Data Center started to develop MATISSE (Multi-purposed Advanced Tool for the Instruments for the Solar System Exploration - http://tools.asdc.asi.it/matisse.jsp) in late 2012. This tool allows 3D web-based visualization of data acquired by planetary exploration missions: the output could either be the straightforward projection of the selected observation over the shape model of the target body or the visualization of a high-order product (average/mosaic, difference, ratio, RGB) computed directly online with MATISSE. Standard outputs of the tool also comprise downloadable files to be used with GIS software (GeoTIFF and ENVI format) and 3D very high-resolution files to be viewed by means of the free software Paraview. During this period the first and most frequent exploitation of the tool has been related to visualization of data acquired by VIRTIS-M instruments onboard Rosetta observing the comet 67P. The success of this task, well represented by the good number of published works that used images made with MATISSE confirmed the need of a different approach to correctly visualize data coming from irregular shaped bodies. In the next future the datasets available to MATISSE are planned to be extended, starting from the addition of VIR-Dawn observations of both Vesta and Ceres and also using standard protocols to access data stored in external repositories, such as NASA ODE and Planetary VO.

  10. Large-Scale Overlays and Trends: Visually Mining, Panning and Zooming the Observable Universe.

    PubMed

    Luciani, Timothy Basil; Cherinka, Brian; Oliphant, Daniel; Myers, Sean; Wood-Vasey, W Michael; Labrinidis, Alexandros; Marai, G Elisabeta

    2014-07-01

    We introduce a web-based computing infrastructure to assist the visual integration, mining and interactive navigation of large-scale astronomy observations. Following an analysis of the application domain, we design a client-server architecture to fetch distributed image data and to partition local data into a spatial index structure that allows prefix-matching of spatial objects. In conjunction with hardware-accelerated pixel-based overlays and an online cross-registration pipeline, this approach allows the fetching, displaying, panning and zooming of gigabit panoramas of the sky in real time. To further facilitate the integration and mining of spatial and non-spatial data, we introduce interactive trend images-compact visual representations for identifying outlier objects and for studying trends within large collections of spatial objects of a given class. In a demonstration, images from three sky surveys (SDSS, FIRST and simulated LSST results) are cross-registered and integrated as overlays, allowing cross-spectrum analysis of astronomy observations. Trend images are interactively generated from catalog data and used to visually mine astronomy observations of similar type. The front-end of the infrastructure uses the web technologies WebGL and HTML5 to enable cross-platform, web-based functionality. Our approach attains interactive rendering framerates; its power and flexibility enables it to serve the needs of the astronomy community. Evaluation on three case studies, as well as feedback from domain experts emphasize the benefits of this visual approach to the observational astronomy field; and its potential benefits to large scale geospatial visualization in general.

  11. Large-Scale Overlays and Trends: Visually Mining, Panning and Zooming the Observable Universe.

    PubMed

    Luciani, Timothy Basil; Cherinka, Brian; Oliphant, Daniel; Myers, Sean; Wood-Vasey, W Michael; Labrinidis, Alexandros; Marai, G Elisabeta

    2014-07-01

    We introduce a web-based computing infrastructure to assist the visual integration, mining and interactive navigation of large-scale astronomy observations. Following an analysis of the application domain, we design a client-server architecture to fetch distributed image data and to partition local data into a spatial index structure that allows prefix-matching of spatial objects. In conjunction with hardware-accelerated pixel-based overlays and an online cross-registration pipeline, this approach allows the fetching, displaying, panning and zooming of gigabit panoramas of the sky in real time. To further facilitate the integration and mining of spatial and non-spatial data, we introduce interactive trend images-compact visual representations for identifying outlier objects and for studying trends within large collections of spatial objects of a given class. In a demonstration, images from three sky surveys (SDSS, FIRST and simulated LSST results) are cross-registered and integrated as overlays, allowing cross-spectrum analysis of astronomy observations. Trend images are interactively generated from catalog data and used to visually mine astronomy observations of similar type. The front-end of the infrastructure uses the web technologies WebGL and HTML5 to enable cross-platform, web-based functionality. Our approach attains interactive rendering framerates; its power and flexibility enables it to serve the needs of the astronomy community. Evaluation on three case studies, as well as feedback from domain experts emphasize the benefits of this visual approach to the observational astronomy field; and its potential benefits to large scale geospatial visualization in general. PMID:26357360

  12. A model of visually-guided smooth pursuit eye movements based on behavioral observations.

    PubMed

    Krauzlis, R J; Lisberger, S G

    1994-12-01

    We report a model that reproduces many of the behavioral properties of smooth pursuit eye movements. The model is a negative-feedback system that uses three parallel visual motion pathways to drive pursuit. The three visual pathways process image motion, defined as target motion with respect to the moving eye, and provide signals related to image velocity, image acceleration, and a transient that occurs at the onset of target motion. The three visual motion signals are summed and integrated to produce the eye velocity output of the model. The model reproduces the average eye velocity evoked by steps of target velocity in monkeys and humans and accounts for the variation among individual responses and subjects. When its motor pathways are expanded to include positive feedback of eye velocity and a "switch", the model reproduces the exponential decay in eye velocity observed when a moving target stops. Manipulation of this expanded model can mimic the effects of stimulation and lesions in the arcuate pursuit area, the middle temporal visual area (MT), and the medial superior temporal visual area (MST).

  13. Deep Brain Stimulation of the Pedunculopontine Tegmental Nucleus (PPN) Influences Visual Contrast Sensitivity in Human Observers

    PubMed Central

    Strumpf, Hendrik; Noesselt, Toemme; Schoenfeld, Mircea Ariel; Voges, Jürgen; Panther, Patricia; Kaufmann, Joern; Heinze, Hans-Jochen; Hopf, Jens-Max

    2016-01-01

    The parapontine nucleus of the thalamus (PPN) is a neuromodulatory midbrain structure with widespread connectivity to cortical and subcortical motor structures, as well as the spinal cord. The PPN also projects to the thalamus, including visual relay nuclei like the LGN and the pulvinar. Moreover, there is intense connectivity with sensory structures of the tegmentum in particular with the superior colliculus (SC). Given the existence and abundance of projections to visual sensory structures, it is likely that activity in the PPN has some modulatory influence on visual sensory selection. Here we address this possibility by measuring the visual discrimination performance (luminance contrast thresholds) in a group of patients with Parkinson’s Disease (PD) treated with deep-brain stimulation (DBS) of the PPN to control gait and postural motor deficits. In each patient we measured the luminance-contrast threshold of being able to discriminate an orientation-target (Gabor-grating) as a function of stimulation frequency (high 60Hz, low 8/10, no stimulation). Thresholds were determined using a standard staircase-protocol that is based on parameter estimation by sequential testing (PEST). We observed that under low frequency stimulation thresholds increased relative to no and high frequency stimulation in five out of six patients, suggesting that DBS of the PPN has a frequency-dependent impact on visual selection processes at a rather elementary perceptual level. PMID:27167979

  14. Rapid observation of unfixed, unstained human skin biopsy specimens with confocal microscopy and visualization

    NASA Astrophysics Data System (ADS)

    Masters, Barry R.; Aziz, David J.; Gmitro, Arthur F.; Kerr, James H.; O'Grady, Terence C.; Goldman, Leon

    1997-10-01

    The use of reflected light confocal microscopy is proposed to rapidly observe unfixed, unstained biopsy specimens of human skin. Reflected light laser scanning confocal microscopy was used to compare a freshly excised, unfixed, unstained biopsy specimen, and in vivo human skin. Optical sections from the ex vivo biopsy specimen of human skin and in vivo human skin were converted to red-green anaglyphs for 3D visualization. Contrast was derived from intrinsic differences in the scattering properties of the organelles and cells within the tissue. Individual cellular layers were observed in both tissues from the surface to the papillary dermis. Confocal microscopy of an unfixed, unstained biopsy specimen showed cells and cell nuclei of the stratum spinosum. Confocal microscopy of in vivo human skin demonstrated optical sectioning through a hair shaft on the upper hand. The combination of reflected light confocal microscopy and 3D visualization with red-green anaglyphs provides a rapid technique for observing fresh biopsies of human skin.

  15. Looking to Learn: The Effects of Visual Guidance on Observational Learning of the Golf Swing.

    PubMed

    D'Innocenzo, Giorgia; Gonzalez, Claudia C; Williams, A Mark; Bishop, Daniel T

    2016-01-01

    Skilled performers exhibit more efficient gaze patterns than less-skilled counterparts do and they look more frequently at task-relevant regions than at superfluous ones. We examine whether we may guide novices' gaze towards relevant regions during action observation in order to facilitate their learning of a complex motor skill. In a Pre-test-Post-test examination of changes in their execution of the full golf swing, 21 novices viewed one of three videos at intervention: i) a skilled golfer performing 10 swings (Free Viewing, FV); ii) the same video with transient colour cues superimposed to highlight key features of the setup (Visual Guidance; VG); iii) or a History of Golf video (Control). Participants in the visual guidance group spent significantly more time looking at cued areas than did the other two groups, a phenomenon that persisted after the cues had been removed. Moreover, the visual guidance group improved their swing execution at Post-test and on a Retention test one week later. Our results suggest that visual guidance to cued areas during observational learning of complex motor skills may accelerate acquisition of the skill. PMID:27224057

  16. Looking to Learn: The Effects of Visual Guidance on Observational Learning of the Golf Swing.

    PubMed

    D'Innocenzo, Giorgia; Gonzalez, Claudia C; Williams, A Mark; Bishop, Daniel T

    2016-01-01

    Skilled performers exhibit more efficient gaze patterns than less-skilled counterparts do and they look more frequently at task-relevant regions than at superfluous ones. We examine whether we may guide novices' gaze towards relevant regions during action observation in order to facilitate their learning of a complex motor skill. In a Pre-test-Post-test examination of changes in their execution of the full golf swing, 21 novices viewed one of three videos at intervention: i) a skilled golfer performing 10 swings (Free Viewing, FV); ii) the same video with transient colour cues superimposed to highlight key features of the setup (Visual Guidance; VG); iii) or a History of Golf video (Control). Participants in the visual guidance group spent significantly more time looking at cued areas than did the other two groups, a phenomenon that persisted after the cues had been removed. Moreover, the visual guidance group improved their swing execution at Post-test and on a Retention test one week later. Our results suggest that visual guidance to cued areas during observational learning of complex motor skills may accelerate acquisition of the skill.

  17. Looking to Learn: The Effects of Visual Guidance on Observational Learning of the Golf Swing

    PubMed Central

    Gonzalez, Claudia C.; Williams, A. Mark

    2016-01-01

    Skilled performers exhibit more efficient gaze patterns than less-skilled counterparts do and they look more frequently at task-relevant regions than at superfluous ones. We examine whether we may guide novices’ gaze towards relevant regions during action observation in order to facilitate their learning of a complex motor skill. In a Pre-test-Post-test examination of changes in their execution of the full golf swing, 21 novices viewed one of three videos at intervention: i) a skilled golfer performing 10 swings (Free Viewing, FV); ii) the same video with transient colour cues superimposed to highlight key features of the setup (Visual Guidance; VG); iii) or a History of Golf video (Control). Participants in the visual guidance group spent significantly more time looking at cued areas than did the other two groups, a phenomenon that persisted after the cues had been removed. Moreover, the visual guidance group improved their swing execution at Post-test and on a Retention test one week later. Our results suggest that visual guidance to cued areas during observational learning of complex motor skills may accelerate acquisition of the skill. PMID:27224057

  18. Measuring Learning Styles with Questionnaires versus Direct Observation of Preferential Choice Behavior in Authentic Learning Situations: The Visualizer/Verbalizer Behavior Observation Scale (VV-BOS).

    ERIC Educational Resources Information Center

    Leutner, Detlev; Plass, Jan L.

    1998-01-01

    Describes the development of the VV-BOS (Visualizer/Verbalizer Behavior Observation Scale), a computer-based instrument for direct observation of students' preferences for visual or verbal learning material. Results of a study with second-language learners indicated a high degree of reliability as an alternative to conventional questionnaires.…

  19. The influence of visual perspective on the somatosensory steady-state response during pain observation

    PubMed Central

    Canizales, Dora L.; Voisin, Julien I. A.; Michon, Pierre-Emmanuel; Roy, Marc-André; Jackson, Philip L.

    2013-01-01

    The observation and evaluation of other’s pain activate part of the neuronal network involved in the actual experience of pain, including those regions subserving the sensori-discriminative dimension of pain. This was largely interpreted as evidence showing that part of the painful experience can be shared vicariously. Here, we investigated the effect of the visual perspective from which other people’s pain is seen on the cortical response to continuous 25 Hz non-painful somatosensory stimulation (somatosensory steady-state response: SSSR). Based on the shared representation framework, we expected first-person visual perspective (1PP) to yield more changes in cortical activity than third-person visual perspective (3PP) during pain observation. Twenty healthy adults were instructed to rate a series of pseudo-dynamic pictures depicting hands in either painful or non-painful scenarios, presented either in 1PP (0–45° angle) or 3PP (180° angle), while changes in brain activity was measured with a 128-electode EEG system. The ratings demonstrated that the same scenarios were rated on average as more painful when observed from the 1PP than from the 3PP. As expected from previous works, the SSSR response was decreased after stimulus onset over the left caudal part of the parieto-central cortex, contralateral to the stimulation side. Moreover, the difference between the SSSR was of greater amplitude when the painful situations were presented from the 1PP compared to the 3PP. Together, these results suggest that a visuospatial congruence between the viewer and the observed scenarios is associated with both a higher subjective evaluation of pain and an increased modulation in the somatosensory representation of observed pain. These findings are discussed with regards to the potential role of visual perspective in pain communication and empathy. PMID:24367323

  20. Skylab-4 visual observations project: Geological features of southwestern North America

    NASA Technical Reports Server (NTRS)

    Silver, L. T.

    1975-01-01

    Visual observations conducted by Skylab-4 crewmen on seven designated geological target areas and other targets of opportunity in parts of southwestern United States and northwestern Mexico were described. The experiments were designed to learn how effectively geologic features could be observed from orbit and what research information could be obtained from the observations when supported by ground studies. For the limited preparation they received, the crewmen demonstrated exceptional observational ability and produced outstanding photographic studies. They also formulated cogent opinions on how to improve future observational and photo-documentation techniques. From the photographs and other observations, it was possible to obtain significant research contributions to on-going field investigations. These contributions were integrated into other aspects of the ground investigations to the following topics: major faults, regional stratigraphy, occurrence of Precambrian crystalline rocks, mapping of Mesozoic volcanic rocks, regional geology.

  1. Same task, same observers, different values: the problem with visual assessment of breast density

    NASA Astrophysics Data System (ADS)

    Sergeant, Jamie C.; Walshaw, Lani; Wilson, Mary; Seed, Sita; Barr, Nicky; Beetles, Ursula; Boggis, Caroline; Bundred, Sara; Gadde, Soujanya; Lim, Yit; Whiteside, Sigrid; Evans, D. Gareth; Howell, Anthony; Astley, Susan M.

    2013-03-01

    The proportion of radio-opaque fibroglandular tissue in a mammographic image of the breast is a strong and modifiable risk factor for breast cancer. Subjective, area-based estimates made by expert observers provide a simple and efficient way of measuring breast density within a screening programme, but the degree of variability may render the reliable identification of women at increased risk impossible. This study examines the repeatability of visual assessment of percent breast density by expert observers. Five consultant radiologists and two breast physicians, all with at least two years' experience in mammographic density assessment, were presented with 100 digital mammogram cases for which they had estimated density at least 12 months previously. Estimates of percent density were made for each mammographic view and recorded on a printed visual analogue scale. The level of agreement between the two sets of estimates was assessed graphically using Bland-Altman plots. All but one observer had a mean difference of less than 6 percentage points, while the largest mean difference was 14.66 percentage points. The narrowest 95% limits of agreement for the differences were -11.15 to 17.35 and the widest were -13.95 to 40.43. Coefficients of repeatability ranged from 14.40 to 38.60. Although visual assessment of breast density has been shown to be strongly associated with cancer risk, the lack of agreement shown here between repeat assessments of the same images by the same observers questions the reliability of using visual assessment to identify women at high risk or to detect moderate changes in breast density over time.

  2. Virtual Observatories for Space Physics Observations and Simulations: New Routes to Efficient Access and Visualization

    NASA Technical Reports Server (NTRS)

    Roberts, Aaron

    2005-01-01

    New tools for data access and visualization promise to make the analysis of space plasma data both more efficient and more powerful, especially for answering questions about the global structure and dynamics of the Sun-Earth system. We will show how new existing tools (particularly the Virtual Space Physics Observatory-VSPO-and the Visual System for Browsing, Analysis and Retrieval of Data-ViSBARD; look for the acronyms in Google) already provide rapid access to such information as spacecraft orbits, browse plots, and detailed data, as well as visualizations that can quickly unite our view of multispacecraft observations. We will show movies illustrating multispacecraft observations of the solar wind and magnetosphere during a magnetic storm, and of simulations of 3 0-spacecraft observations derived from MHD simulations of the magnetosphere sampled along likely trajectories of the spacecraft for the MagCon mission. An important issue remaining to be solved is how best to integrate simulation data and services into the Virtual Observatory environment, and this talk will hopefully stimulate further discussion along these lines.

  3. The American Association of Variable Star Observers as a Professional-Amateur Astronomical Community of practice

    NASA Astrophysics Data System (ADS)

    Kafka, Stella; 6173540484

    2016-06-01

    The AAVSO was formed in 1911 as a group of US-based amateur observers obtaining data in support of professional astronomy projects. Now, it has evolved into an International Organization with members and observers in all continents, contributing photometry to a public database of about 22,000 variable objects. I will present main aspects of the association and how it has evolved with time to a premium resource for variable star research. I will also discuss current projects and opportunities for Professional-Amateur collaborations within the AAVSO, building a stronger international community of variable star observers!

  4. A distributed analysis and visualization system for model and observational data

    NASA Technical Reports Server (NTRS)

    Wilhelmson, Robert B.

    1994-01-01

    Software was developed with NASA support to aid in the analysis and display of the massive amounts of data generated from satellites, observational field programs, and from model simulations. This software was developed in the context of the PATHFINDER (Probing ATmospHeric Flows in an Interactive and Distributed EnviRonment) Project. The overall aim of this project is to create a flexible, modular, and distributed environment for data handling, modeling simulations, data analysis, and visualization of atmospheric and fluid flows. Software completed with NASA support includes GEMPAK analysis, data handling, and display modules for which collaborators at NASA had primary responsibility, and prototype software modules for three-dimensional interactive and distributed control and display as well as data handling, for which NSCA was responsible. Overall process control was handled through a scientific and visualization application builder from Silicon Graphics known as the Iris Explorer. In addition, the GEMPAK related work (GEMVIS) was also ported to the Advanced Visualization System (AVS) application builder. Many modules were developed to enhance those already available in Iris Explorer including HDF file support, improved visualization and display, simple lattice math, and the handling of metadata through development of a new grid datatype. Complete source and runtime binaries along with on-line documentation is available via the World Wide Web at: http://redrock.ncsa.uiuc.edu/ PATHFINDER/pathre12/top/top.html.

  5. Automation of Coordinated Planning Between Observatories: The Visual Observation Layout Tool (VOLT)

    NASA Technical Reports Server (NTRS)

    Maks, Lori; Koratkar, Anuradha; Kerbel, Uri; Pell, Vince

    2002-01-01

    Fulfilling the promise of the era of great observatories, NASA now has more than three space-based astronomical telescopes operating in different wavebands. This situation provides astronomers with the unique opportunity of simultaneously observing a target in multiple wavebands with these observatories. Currently scheduling multiple observatories simultaneously, for coordinated observations, is highly inefficient. Coordinated observations require painstaking manual collaboration among the observatory staff at each observatory. Because they are time-consuming and expensive to schedule, observatories often limit the number of coordinated observations that can be conducted. In order to exploit new paradigms for observatory operation, the Advanced Architectures and Automation Branch of NASA's Goddard Space Flight Center has developed a tool called the Visual Observation Layout Tool (VOLT). The main objective of VOLT is to provide a visual tool to automate the planning of coordinated observations by multiple astronomical observatories. Four of NASA's space-based astronomical observatories - the Hubble Space Telescope (HST), Far Ultraviolet Spectroscopic Explorer (FUSE), Rossi X-ray Timing Explorer (RXTE) and Chandra - are enthusiastically pursuing the use of VOLT. This paper will focus on the purpose for developing VOLT, as well as the lessons learned during the infusion of VOLT into the planning and scheduling operations of these observatories.

  6. Bulgarian - Serbian collaboration: CCD observations of visual double and multiple stars and extragalactic radio sources

    NASA Astrophysics Data System (ADS)

    Cvetković, Zorica; Pavlović, Rade; Damljanović, Goran; Boeva, Svetlana; Latev, Georgi

    The Serbian-Bulgarian cooperation concerning the study of visual double and multiple stars started in 2004 with CCD observations of such objects, and in 2011 was extended to observations of extragalactic radio sources visible at optical wavelengths. Here we present a brief overview of the most interesting results obtained during our collaboration. Begun as a regional Balkan project, this cooperation in 2012 was continued in the form of a bilateral cooperation between the Bulgarian Academy of Sciences and Serbian Academy of Sciences and Arts.

  7. How Clean Are Hotel Rooms? Part I: Visual Observations vs. Microbiological Contamination.

    PubMed

    Almanza, Barbara A; Kirsch, Katie; Kline, Sheryl Fried; Sirsat, Sujata; Stroia, Olivia; Choi, Jin Kyung; Neal, Jay

    2015-01-01

    Current evidence of hotel room cleanliness is based on observation rather than empirically based microbial assessment. The purpose of the study described here was to determine if observation provides an accurate indicator of cleanliness. Results demonstrated that visual assessment did not accurately predict microbial contamination. Although testing standards have not yet been established for hotel rooms and will be evaluated in Part II of the authors' study, potential microbial hazards included the sponge and mop (housekeeping cart), toilet, bathroom floor, bathroom sink, and light switch. Hotel managers should increase cleaning in key areas to reduce guest exposure to harmful bacteria. PMID:26427262

  8. Successful Hybrid Approach to Visual and Video Observations of the 1999 Leonid Storm

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Crawford, Chris; Butow, Steve; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    A new hybrid technique of visual and video meteor observations is described. The method proved particularly effective for airborne observations of meteor shower activity. Results from the 1999 Leonid Multi-Instrument Aircraft Campaign are presented, and the profile shape of the 1999 Leonid storm is discussed in relation to meteor shower models. We find that the storm is best described with a Lorentz profile. Application to past meteor outbursts shows that the cui,rent multi-trailet model of a dust trail is slightly shifted and we crossed deeper into the 1899 epoch trallet than expected.

  9. More clinical observations on migraine associated with monocular visual symptoms in an Indian population

    PubMed Central

    Jogi, Vishal; Mehta, Sahil; Gupta, Amod; Singh, Paramjeet; Lal, Vivek

    2016-01-01

    Context: Retinal migraine (RM) is considered as one of the rare causes of transient monocular visual loss (TMVL) and has not been studied in Indian population. Objectives: The study aims to analyze the clinical and investigational profile of patients with RM. Materials and Methods: This is an observational prospective analysis of 12 cases of TMVL fulfilling the International Classification of Headache Disorders-2nd edition (ICHD-II) criteria of RM examined in Neurology and Ophthalmology Outpatient Department (OPD) of Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh from July 2011 to October 2012. Results: Most patients presented in 3rd and 4th decade with equal sex distribution. Seventy-five percent had antecedent migraine without aura (MoA) and 25% had migraine with Aura (MA). Headache was ipsilateral to visual symptoms in 67% and bilateral in 33%. TMVL preceded headache onset in 58% and occurred during headache episode in 42%. Visual symptoms were predominantly negative except in one patient who had positive followed by negative symptoms. Duration of visual symptoms was variable ranging from 30 s to 45 min. None of the patient had permanent monocular vision loss. Three patients had episodes of TMVL without headache in addition to the symptom constellation defining RM. Most of the tests done to rule out alternative causes were normal. Magnetic resonance imaging (MRI) brain showed nonspecific white matter changes in one patient. Visual-evoked potential (VEP) showed prolonged P100 latencies in two cases. Patent foramen ovale was detected in one patient. Conclusions: RM is a definite subtype of migraine and should remain in the ICHD classification. It should be kept as one of the differential diagnosis of transient monocular vision loss. We propose existence of “acephalgic RM” which may respond to migraine prophylaxis. PMID:27011631

  10. Observations of visual sensations produced by Cerenkov radiation from high-energy electrons

    SciTech Connect

    Steidley, K.D.; Eastman, R.M.; Stabile, R.J. )

    1989-09-01

    Ten cancer patients whose eyes were therapeutically irradiated with 6-18 MeV electrons reported visual light sensations. Nine reported seeing blue light and one reported seeing white light. Controls reported seeing no light. Additionally, tests with patients ruled out the x-ray contamination of the electron beam as being important. The photon yield due to Cerenkov radiation produced by radium and its daughters for both electrons and gamma rays was calculated; it was found to account for a turn-of-the-century human observation of the radium phosphene. We conclude that the dominant mechanism of this phosphene is Cerenkov radiation, primarily from betas. From our own patient data, based on the color seen and the Cerenkov production rates, we conclude that the dominant mechanism is Cerenkov radiation and that high-energy electrons are an example of particle induced visual sensations.

  11. Accounting for anatomical noise in SPECT with a visual-search human-model observer

    NASA Astrophysics Data System (ADS)

    Gifford, H. C.; King, M. A.; Smyczynski, M. S.

    2011-03-01

    Reliable human-model observers for clinically realistic detection studies are of considerable interest in medical imaging research, but current model observers require frequent revalidation with human data. A visual-search (VS) observer framework may improve reliability by better simulating realistic etection-localization tasks. Under this framework, model observers execute a holistic search to identify tumor-like candidates and then perform careful analysis of these candidates. With emission tomography, anatomical noise in the form of elevated uptake in neighboring tissue often complicates the task. Some scanning model observers simulate the human ability to read around such noise by presubtracting the mean normal background from the test image, but this backgroundknown- exactly (BKE) assumption has several drawbacks. The extent to which the VS observer can overcome these drawbacks was investigated by comparing it against humans and a scanning observer for detection of solitary pulmonary nodules in a simulated SPECT lung study. Our results indicate that the VS observer offers a robust alternative to the scanning observer for modeling humans.

  12. Spatiotemporal multiplexing method for visual field of view extension in holographic displays with naked eye observation

    NASA Astrophysics Data System (ADS)

    Finke, G.; Kujawińska, M.; Kozacki, T.; Zaperty, W.

    2016-09-01

    In this paper we propose a method which allows to overcome the basic functional problems in holographic displays with naked eye observation caused by delivering too small images visible in narrow viewing angles. The solution is based on combining the spatiotemporal multiplexing method with a 4f optical system. It enables to increase an aperture of a holographic display and extend the angular visual field of view. The applicability of the modified display is evidenced by Wigner distribution analysis of holographic imaging with spatiotemporal multiplexing method and by the experiments performed at the display demonstrator.

  13. The 1986-87 apparition of Saturn - visual and photographic observations

    SciTech Connect

    Benton, J.L. Jr. )

    1989-07-01

    Visual and photographic studies of the planet Saturn and its Ring System were carried out by ALPO Saturn Section observers between Feb. 7, 1987 and Oct. 18, 1987. Saturn showed about the same level of atmospheric activity in 1986-87 as was apparent in 1985-85. The northerly inclination of the ring plane, reaching +26.812 deg during this period, exposed the Northern Hemisphere of Saturn's globe and the northern face of its Ring System. The text is accompanied by tables, graphs, and references.

  14. SVM-based visual-search model observers for PET tumor detection

    NASA Astrophysics Data System (ADS)

    Gifford, Howard C.; Sen, Anando; Azencott, Robert

    2015-03-01

    Many search-capable model observers follow task paradigms that specify clinically unrealistic prior knowledge about the anatomical backgrounds in study images. Visual-search (VS) observers, which implement distinct, feature-based candidate search and analysis stages, may provide a means of avoiding such paradigms. However, VS observers that conduct single-feature analysis have not been reliable in the absence of any background information. We investigated whether a VS observer based on multifeature analysis can overcome this background dependence. The testbed was a localization ROC (LROC) study with simulated whole-body PET images. Four target-dependent morphological features were defined in terms of 2D cross-correlations involving a known tumor profile and the test image. The feature values at the candidate locations in a set of training images were fed to a support-vector machine (SVM) to compute a linear discriminant that classified locations as tumor-present or tumor-absent. The LROC performance of this SVM-based VS observer was compared against the performances of human observers and a pair of existing model observers.

  15. Assessing the GOANNA Visual Field Algorithm Using Artificial Scotoma Generation on Human Observers

    PubMed Central

    Chong, Luke X.; Turpin, Andrew; McKendrick, Allison M.

    2016-01-01

    Purpose To validate the performance of a new perimetric algorithm (Gradient-Oriented Automated Natural Neighbor Approach; GOANNA) in humans using a novel combination of computer simulation and human testing, which we call Artificial Scotoma Generation (ASG). Methods Fifteen healthy observers were recruited. Baseline conventional automated perimetry was performed on the Octopus 900. Visual field sensitivity was measured using two different procedures: GOANNA and Zippy Estimation by Sequential Testing (ZEST). Four different scotoma types were induced in each observer by implementing a novel technique that inserts a step between the algorithm and the perimeter, which in turn alters presentation levels to simulate scotomata in human observers. Accuracy, precision, and unique number of locations tested were measured, with the maximum difference between a location and its neighbors (Max_d) used to stratify results. Results GOANNA sampled significantly more locations than ZEST (paired t-test, P < 0.001), while maintaining comparable test times. Difference plots showed that GOANNA displayed greater accuracy than ZEST when Max_d was in the 10 to 30 dB range (with the exception of Max_d = 20 dB; Wilcoxon, P < 0.001). Similarly, GOANNA demonstrated greater precision than ZEST when Max_d was in the 20 to 30 dB range (Wilcoxon, P < 0.001). Conclusions We have introduced a novel method for assessing accuracy of perimetric algorithms in human observers. Results observed in the current study agreed with the results seen in earlier simulation studies, and thus provide support for performing larger scale clinical trials with GOANNA in the future. Translational Relevance The GOANNA perimetric testing algorithm offers a new paradigm for visual field testing where locations for testing are chosen that target scotoma borders. Further, the ASG methodology used in this paper to assess GOANNA shows promise as a hybrid between computer simulation and patient testing, which may allow more

  16. Assessing the GOANNA Visual Field Algorithm Using Artificial Scotoma Generation on Human Observers

    PubMed Central

    Chong, Luke X.; Turpin, Andrew; McKendrick, Allison M.

    2016-01-01

    Purpose To validate the performance of a new perimetric algorithm (Gradient-Oriented Automated Natural Neighbor Approach; GOANNA) in humans using a novel combination of computer simulation and human testing, which we call Artificial Scotoma Generation (ASG). Methods Fifteen healthy observers were recruited. Baseline conventional automated perimetry was performed on the Octopus 900. Visual field sensitivity was measured using two different procedures: GOANNA and Zippy Estimation by Sequential Testing (ZEST). Four different scotoma types were induced in each observer by implementing a novel technique that inserts a step between the algorithm and the perimeter, which in turn alters presentation levels to simulate scotomata in human observers. Accuracy, precision, and unique number of locations tested were measured, with the maximum difference between a location and its neighbors (Max_d) used to stratify results. Results GOANNA sampled significantly more locations than ZEST (paired t-test, P < 0.001), while maintaining comparable test times. Difference plots showed that GOANNA displayed greater accuracy than ZEST when Max_d was in the 10 to 30 dB range (with the exception of Max_d = 20 dB; Wilcoxon, P < 0.001). Similarly, GOANNA demonstrated greater precision than ZEST when Max_d was in the 20 to 30 dB range (Wilcoxon, P < 0.001). Conclusions We have introduced a novel method for assessing accuracy of perimetric algorithms in human observers. Results observed in the current study agreed with the results seen in earlier simulation studies, and thus provide support for performing larger scale clinical trials with GOANNA in the future. Translational Relevance The GOANNA perimetric testing algorithm offers a new paradigm for visual field testing where locations for testing are chosen that target scotoma borders. Further, the ASG methodology used in this paper to assess GOANNA shows promise as a hybrid between computer simulation and patient testing, which may allow more

  17. Pseudo-Real-Time Signal Visualization during Pulsar Observations on the Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Kelly, C. J.; O'Neil, K.

    2004-12-01

    Pseudo-Real-Time Signal Visualization during Pulsar Observations on the Green Bank Telescope J. Kelly (Rockbridge County Public Schools & NRAO), K. O'Neil (NRAO) When using the Robert C. Byrd Green Bank Telescope (GBT) for pulsar observations, observers need to be able to insure the data reaching the observer is of the highest quality possible. To do this, telescope users need to be able to monitor, in real time, the raw signal intensity of data as it flows in from the GBT. In the summer of 2004 at NRAO-Greenbank, my Research Experience For Teachers project was spent developing this utility. For portability and compatibility, the computer language python was used to build the visualization utility. The major hurdle in developing the python modules was in reading and manipulating the tremendous quantity of unprocessed data acquired during an observation. (The spigot data rate is set to be 25 Mb/s.) The data stream is intercepted by a "spigot" card, buffered and then stored on a hard drive as a series of binary files. The python modules attempt to read, parse and organize these binary files to ultimately produce a simple intensity versus time plot of the data stream. The modules developed run as a loop to update the plot several times per minute. Integrating the knowledge and experience of this research in the classroom involves an introductory unit on radio astronomy and astrophysics. Additionally, students will have the opportunity to analyze data collected from the Crab Nebula Pulsar and experience backend processes such as data folding. These activities will be described. This work was funded by the National Science Foundation RET program.

  18. Astrometric observations of visual binaries using 26-inch refractor during 2007-2014 at Pulkovo

    NASA Astrophysics Data System (ADS)

    Izmailov, I. S.; Roshchina, E. A.

    2016-04-01

    We present the results of 15184 astrometric observations of 322 visual binaries carried out in 2007-2014 at Pulkovo observatory. In 2007, the 26-inch refractor ( F = 10413 mm, D = 65 cm) was equipped with the CCD camera FLI ProLine 09000 (FOV 12' × 12', 3056 × 3056 pixels, 0.238 arcsec pixel-1). Telescope automation and weather monitoring system installation allowed us to increase the number of observations significantly. Visual binary and multiple systems with an angular distance in the interval 1."1-78."6 with 7."3 on average were included in the observing program. The results were studied in detail for systematic errors using calibration star pairs. There was no detected dependence of errors on temperature, pressure, and hour angle. The dependence of the 26-inch refractor's scale on temperature was taken into account in calculations. The accuracy of measurement of a single CCD image is in the range of 0."0005 to 0."289, 0."021 on average along both coordinates. Mean errors in annual average values of angular distance and position angle are equal to 0."005 and 0.°04 respectively. The results are available here http://izmccd.puldb.ru/vds.htmand in the Strasbourg Astronomical Data Center (CDS). In the catalog, the separations and position angles per night of observation and annual average as well as errors for all the values and standard deviations of a single observation are presented. We present the results of comparison of 50 pairs of stars with known orbital solutions with ephemerides.

  19. Masked target transform volume clutter metric for human observer visual search modeling

    NASA Astrophysics Data System (ADS)

    Moore, Richard Kirk

    The Night Vision and Electronic Sensors Directorate (NVESD) develops an imaging system performance model to aid in the design and comparison of imaging systems for military use. It is intended to approximate visual task performance for a typical human observer with an imaging system of specified optical, electrical, physical, and environmental parameters. When modeling search performance, the model currently uses only target size and target-to-background contrast to describe a scene. The presence or absence of other non-target objects and textures in the scene also affect search performance, but NVESD's targeting task performance metric based time limited search model (TTP/TLS) does not currently account for them explicitly. Non-target objects in a scene that impact search performance are referred to as clutter. A universally accepted mathematical definition of clutter does not yet exist. Researchers have proposed a number of clutter metrics based on very different methods, but none account for display geometry or the varying spatial frequency sensitivity of the human visual system. After a review of the NVESD search model, properties of the human visual system, and a literature review of clutter metrics, the new masked target transform volume clutter metric will be presented. Next the results of an experiment designed to show performance variation due to clutter alone will be presented. Then, the results of three separate perception experiments using real or realistic search imagery will be used to show that the new clutter metric better models human observer search performance than the current NVESD model or any of the reviewed clutter metrics.

  20. Time-varying spatial data integration and visualization: 4 Dimensions Environmental Observations Platform (4-DEOS)

    NASA Astrophysics Data System (ADS)

    Paciello, Rossana; Coviello, Irina; Filizzola, Carolina; Genzano, Nicola; Lisi, Mariano; Mazzeo, Giuseppe; Pergola, Nicola; Sileo, Giancanio; Tramutoli, Valerio

    2014-05-01

    In environmental studies the integration of heterogeneous and time-varying data, is a very common requirement for investigating and possibly visualize correlations among physical parameters underlying the dynamics of complex phenomena. Datasets used in such kind of applications has often different spatial and temporal resolutions. In some case superimposition of asynchronous layers is required. Traditionally the platforms used to perform spatio-temporal visual data analyses allow to overlay spatial data, managing the time using 'snapshot' data model, each stack of layers being labeled with different time. But this kind of architecture does not incorporate the temporal indexing neither the third spatial dimension which is usually given as an independent additional layer. Conversely, the full representation of a generic environmental parameter P(x,y,z,t) in the 4D space-time domain could allow to handle asynchronous datasets as well as less traditional data-products (e.g. vertical sections, punctual time-series, etc.) . In this paper we present the 4 Dimensions Environmental Observation Platform (4-DEOS), a system based on a web services architecture Client-Broker-Server. This platform is a new open source solution for both a timely access and an easy integration and visualization of heterogeneous (maps, vertical profiles or sections, punctual time series, etc.) asynchronous, geospatial products. The innovative aspect of the 4-DEOS system is that users can analyze data/products individually moving through time, having also the possibility to stop the display of some data/products and focus on other parameters for better studying their temporal evolution. This platform gives the opportunity to choose between two distinct display modes for time interval or for single instant. Users can choose to visualize data/products in two ways: i) showing each parameter in a dedicated window or ii) visualize all parameters overlapped in a single window. A sliding time bar, allows

  1. September Showers in Visual Observations of the Polish Comet and Meteor Workshop

    NASA Astrophysics Data System (ADS)

    Wiśniewski, M.

    We present the results of the visual observations made by Polish meteor observers during the end of August, September and the beginning of October in years 1996 - 2000. These results are based on the coordinates and velocities of 6723 plotted meteors. Analyzing our data using the Radiant software we detected clear radiants of the alpha-Aurigids and the Southern Piscids. We found a trace of double structure of the kappa-Aquarid radiant and only weak traces of the delta-Aurigids and the pi-Eridanids. There is no the October Capricornids and the sigma-Orionid radiants in our data. Our calculations strongly suggest that meteors from the telescopic shower of alpha-Triangulids is seen also in visual data. We propose that there are few new showers active in September. First of them (alpha-Cepheids) is probably active from August 20 to September 20 with V_infty = 65 km/s and equatorial coordinates of the radiant: alpha = 320 deg, delta = +65 deg. Second (iota-Cygnids) is probably active from September 1 to 20 with V_infty = 45 km/s and equatorial coordinates alpha = 296 deg, delta = +50 deg. Third (September Draconids) is active from September 1 to 25 with V_infty = 20 km/s and equatorial coordinates alpha = 236 deg, delta = +47 deg.

  2. Assessment of prostate cancer detection with a visual-search human model observer

    NASA Astrophysics Data System (ADS)

    Sen, Anando; Kalantari, Faraz; Gifford, Howard C.

    2014-03-01

    Early staging of prostate cancer (PC) is a significant challenge, in part because of the small tumor sizes in- volved. Our long-term goal is to determine realistic diagnostic task performance benchmarks for standard PC imaging with single photon emission computed tomography (SPECT). This paper reports on a localization receiver operator characteristic (LROC) validation study comparing human and model observers. The study made use of a digital anthropomorphic phantom and one-cm tumors within the prostate and pelvic lymph nodes. Uptake values were consistent with data obtained from clinical In-111 ProstaScint scans. The SPECT simulation modeled a parallel-hole imaging geometry with medium-energy collimators. Nonuniform attenua- tion and distance-dependent detector response were accounted for both in the imaging and the ordered-subset expectation-maximization (OSEM) iterative reconstruction. The observer study made use of 2D slices extracted from reconstructed volumes. All observers were informed about the prostate and nodal locations in an image. Iteration number and the level of postreconstruction smoothing were study parameters. The results show that a visual-search (VS) model observer correlates better with the average detection performance of human observers than does a scanning channelized nonprewhitening (CNPW) model observer.

  3. Observations, Analysis, and Orbital Calculation of the Visual Double Star STTA 123 AB

    NASA Astrophysics Data System (ADS)

    Brashear, Nicholas; Camama, Angel; Drake, Miles; Smith, Miranda; Johnson, Jolyon; Arnold, Dave; Chamberlain, Rebecca

    2012-04-01

    As part of a research workshop at Pine Mountain Observatory, four students from Evergreen State College met with an instructor and an experienced double star observer to learn the methods used to measure double stars and to contribute observations to the Washington Double Star (WDS) Catalog. The students then observed and analyzed the visual double star STTA 123 AB with few past observations in the WDS Catalog to determine if it is optical or binary in nature. The separation of this double star was found to be 69.9" and its position angle to be 148.0°. Using the spectral types, stellar parallaxes, and proper motion vectors of these two stars, the students determined that this double star is likely physically bound by gravity in a binary system. Johnson calculated a preliminary circular orbit for the system using Newton's version of Kepler's third law. The masses of the two stars were estimated based on their spectral types (F0) to be 1.4 Msun. Their separation was estimated to be 316 AU based on their distance from Earth (about 216.5 light years) and their orbital period was estimated to be 3357 years. Arnold compared the observations made by the students to what would be predicted by the orbit calculation. A discrepancy of 14° was found in the position angle. The authors suggest that the orbit is both eccentric and inclined to our line of sight, making the observed position angle change less than predicted.

  4. Visual influences on sensorimotor EEG responses during observation of hand actions.

    PubMed

    Drew, Ashley R; Quandt, Lorna C; Marshall, Peter J

    2015-02-01

    There is growing interest within the field of social-cognitive neuroscience in the dynamics of sensorimotor EEG rhythms during the observation of actions performed by others. However, there remain important gaps in the literature regarding the effects of perceptual aspects of the observed hand movements. This study investigated two visual influences on the EEG response to hand actions. Specifically, the perspective of the action in relation to the participant (egocentric/allocentric) was varied and the effect of the hand used to carry out the action (left/right) was also assessed. While EEG was recorded, 28 undergraduate participants observed video clips showing an actor's hand reaching for, grasping, and lifting a cylindrical object across four conditions (right-hand egocentric, left-hand egocentric, right-hand allocentric, and left-hand allocentric). For actions viewed from an egocentric perspective, significantly greater event-related desynchronization (ERD) was present in the 7-9 Hz range over right mid-frontal, right central, and bilateral mid-parietal sites for right-handed actions compared to left-handed actions. In addition, greater ERD was observed within the 7-9 Hz band during the observation of right-handed egocentric actions compared to actions viewed from the allocentric perspective. This finding was present at bilateral central and mid-parietal sites, and emerged as an anticipatory effect prior to the onset of the observed hand movements.

  5. A distributed analysis and visualization system for model and observational data

    NASA Technical Reports Server (NTRS)

    Wilhelmson, Robert; Koch, Steven

    1993-01-01

    The objective of this proposal is to develop an integrated and distributed analysis and display software system which can be applied to all areas of the Earth System Science to study numerical model and earth observational data from storm to global scale. This system will be designed to be easy to use, portable, flexible and easily extensible and designed to adhere to current and emerging standards whenever possible. It will provide an environment for visualization of the massive amounts of data generated from satellites and other observational field measurements and from model simulations during or after their execution. Two- and three-dimensional animation will also be provided. This system will be based on a widely used software package from NASA called GEMPAK and prototype software for three-dimensional interactive displays built at NCSA. The underlying foundation of the system will be a set of software libraries which can be distributed across a UNIX based supercomputer and workstations.

  6. A distributed analysis and visualization system for model and observational data

    NASA Technical Reports Server (NTRS)

    Wilhelmson, Robert; Koch, Steven

    1992-01-01

    The objective of this proposal is to develop an integrated and distributed analysis and display software system which can be applied to all areas of the Earth System Science to study numerical model and earth observational data from storm to global scale. This system will be designed to be easy to use, portable, flexible and easily extensible and to adhere to current and emerging standards whenever possible. It will provide an environment for visualization of the massive amounts of data generated from satellites and other observational field measurements and from model simulations during or after their execution. Two- and three-dimensional animation will also be provided. This system will be based on a widely used software package from NASA called GEMPAK and prototype software for three dimensional interactive displays built at NCSA. The underlying foundation of the system will be a set of software libraries which can be distributed across a UNIX based supercomputer and workstations.

  7. Rotational jitter around the observer's line of sight can facilitate visually induced perception of forward self-motion (forward vection).

    PubMed

    Nakamura, Shinji

    2013-01-01

    Previous studies have shown that the addition of jittering motion into a visual inducer facilitates vection. A psychophysical experiment with 12 observers found that the expanding visual inducer, which contained rotational jitter around the observer's line of sight, can induce stronger forward vection than a pure radial expansion without any additional jittering component. The results suggested that angular rotational jitter can facilitate vection without the enhancement of motion parallax, which has been considered one of the critical factors in explaining jitter effects.

  8. Speckle observations with PISCO in Merate (Italy) - XII. Astrometric measurements of visual binaries in 2011

    NASA Astrophysics Data System (ADS)

    Scardia, M.; Prieur, J.-L.; Pansecchi, L.; Argyle, R. W.; Spanò, P.; Riva, M.; Landoni, M.

    2013-10-01

    We present relative astrometric measurements of visual binaries, made in 2011 with the Pupil Interferometry Speckle camera and COronagraph (PISCO) at the 102-cm Zeiss telescope of the Brera Astronomical Observatory in Merate (Italy). Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained new measurements of 469 objects, with angular separations in the range 0.14-8.1 arcsec, and an average accuracy of 0.02 arcsec. The mean error on the position angles is 0 .^{circ}7. Most of the position angles were determined without the usual 180° ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. Thanks to a new low-magnification option included in PISCO, we have been able to observe fainter stars than previously. The limiting magnitude of our instrumentation on the Zeiss telescope is now close to mV = 10-12, which permits the observation of some red dwarfs. Finally, we present new revised orbits for ADS 8739, 9182 Aa,Ab, 9626 Ba,Bb, 12880 and 14412, partly derived from those observations. The corresponding estimated values for the masses of those systems are compatible with the spectral types.

  9. Visual observation and characterization of fluorescent poly(amido amine) dendrimer in film state.

    PubMed

    Saravanan, Govindachetty; Imae, Toyoko

    2011-06-01

    The fluorescent property of PAMAM dendrimers were examined at film state rather than in solution. The O2-treated PAMAM dendrimer displayed strong blue fluorescence due to its conservation of luminance in the film state and diminished its intensity with degas. The fluorescent property of PAMAM dendrimers was utilized as a fluorescent probe on functional patterned substrates for visual observation by a fluorescence microscope. G4 and G4.5 PAMAM dendrimers having peripheral groups of functional amine and carboxylate, respectively, were adsorbed selectively by electrostatic interactions on patterned carboxylic acid and amine terminated surfaces, respectively resulting in strong fluorescent patterns. This suggests the possible application of fluorescent PAMAM dendrimers as a fluorophor for the visualizable reactions. It was confirmed from an X-ray photoelectron spectroscopy that O2 molecules interact with tertiary amine moiety in PAMAM dendrimers but not amide group. These results give us an important support for the principle of fluorescence phenomenon. PMID:21770112

  10. Titan's lakes and Mare observed by the Visual and Infrared Mapping Spectrometer

    NASA Astrophysics Data System (ADS)

    Brown, R. H.; Soderblom, L. A.; Sotin, C.; Barnes, J. W.; Hayes, A. G.; Lawrence, K. J.; Le Mouelic, S.; Rodriguez, S.; Soderblom, J. M.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Jaumann, R.; Nicholson, P. D.; Stephan, K.

    2012-04-01

    Titan is the only place, besides Earth, that holds stable liquid bodies at its surface. The large Kraken Mare, first seen by ISS [1], was then observed by the radar instrument that discovered a large number of small lakes as well as two other Mare [2]. The liquid nature of these radar-dark features was later confirmed by the specular reflection observed by the Visual and Infrared Mapping Spectrometer (VIMS) over Kraken Mare [3] and by the very low albedo at 5-micron over Ontario Lacus [4]. The three largest lakes are called Mare and are all located in the North Pole area. It is remarkable that most of these lakes have been observed on the North Pole with only one large lake, Ontario lacus, located in the South Pole area. This observation suggests the influence of orbital parameters on the meteorology and the occurrence of rainfalls to refill the depressions [5]. Ethane was detected by the VIMS instrument as one component of Ontario lacus [4]. These lakes and Mare play a key role in Titan's meteorology as demonstrated by recent global circulation models [6]. Determining the composition and the evolution of those lakes has become a primary science objective of the Cassini extended mission. Since Titan entered northern spring in August 2009, the North Pole has been illuminated allowing observations at optical wavelengths. On June 5, 2010 the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft observed the northern pole area with a pixel size from 3 to 7 km. These observations demonstrate that little of the solar flux at 5-micron is scattered by the atmosphere, which allowed us to build a mosaic covering an area of more than 500,000 km2 that overlaps and complements observations made by the Synthetic Aperture Radar (SAR) in 2007. We find that there is an excellent correlation between the shape of the radar dark area, known as Ligeia Mare and the VIMS 5-micron dark unit. Matching most of the radar shoreline, the 2010 VIMS observations suggest

  11. Are Male Judokas with Visual Impairments Training Properly? Findings from an Observational Study

    ERIC Educational Resources Information Center

    Gutierrez-Santiago, Alfonso; Cancela, Jose M.; Zubiaur, Marta; Ayan, Carlos

    2012-01-01

    Introduction: One aim of the study was to describe the temporal structure of judo combat among male judokas with visual impairments. Another aim was to determine the possible differences between the judokas with visual impairments and sighted male judokas to determine whether judokas with visual impairments need specific training to achieve their…

  12. Effect of electrolytes on bubble coalescence in columns observed with visualization techniques.

    PubMed

    Aguilera, María Eugenia; Ojeda, Antonieta; Rondón, Carolina; López De Ramos, Aura

    2002-10-01

    Bubble coalescence and the effect of electrolytes on this phenomenon have been previously studied. This interfacial phenomenon has attracted attention for reactor design/operation and enhanced oil recovery. Predicting bubble coalescence may help prevent low yields in reactors and predict crude oil recovery. Because of the importance of bubble coalescence, the objectives of this work were to improve the accuracy of measuring the percentage of coalescing bubbles and to observe the interfacial gas-liquid behavior. An experimental setup was designed and constructed. Bubble interactions were monitored with a visualization setup. The percentage of air bubble coalescence was 100% in distilled water, about 50% in 0.1 M sodium chloride (NaCl) aqueous solution, and 0% in 0.145 M NaCl aqueous solution. A reduction of the contact gas-liquid area was observed in distillate water. The volume of the resulting bubble was the sum of the original bubble volumes. Repulsion of bubbles was observed in NaCl solutions exceeding 0.07 M. The percentage of bubble coalescence diminishes as the concentration of NaCl chloride increases. High-speed video recording is an accurate technique to measure the percentage of bubble coalescence, and represents an important advance in gas-liquid interfacial studies. PMID:12496024

  13. Effect of electrolytes on bubble coalescence in columns observed with visualization techniques.

    PubMed

    Aguilera, María Eugenia; Ojeda, Antonieta; Rondón, Carolina; López De Ramos, Aura

    2002-10-01

    Bubble coalescence and the effect of electrolytes on this phenomenon have been previously studied. This interfacial phenomenon has attracted attention for reactor design/operation and enhanced oil recovery. Predicting bubble coalescence may help prevent low yields in reactors and predict crude oil recovery. Because of the importance of bubble coalescence, the objectives of this work were to improve the accuracy of measuring the percentage of coalescing bubbles and to observe the interfacial gas-liquid behavior. An experimental setup was designed and constructed. Bubble interactions were monitored with a visualization setup. The percentage of air bubble coalescence was 100% in distilled water, about 50% in 0.1 M sodium chloride (NaCl) aqueous solution, and 0% in 0.145 M NaCl aqueous solution. A reduction of the contact gas-liquid area was observed in distillate water. The volume of the resulting bubble was the sum of the original bubble volumes. Repulsion of bubbles was observed in NaCl solutions exceeding 0.07 M. The percentage of bubble coalescence diminishes as the concentration of NaCl chloride increases. High-speed video recording is an accurate technique to measure the percentage of bubble coalescence, and represents an important advance in gas-liquid interfacial studies.

  14. Observation and visualization: reflections on the relationship between science, visual arts, and the evolution of the scientific image.

    PubMed

    Kolijn, Eveline

    2013-10-01

    The connections between biological sciences, art and printed images are of great interest to the author. She reflects on the historical relevance of visual representations for science. She argues that the connection between art and science seems to have diminished during the twentieth century. However, this connection is currently growing stronger again through digital media and new imaging methods. Scientific illustrations have fuelled art, while visual modeling tools have assisted scientific research. As a print media artist, she explores the relationship between art and science in her studio practice and will present this historical connection with examples related to evolution, microbiology and her own work. Art and science share a common source, which leads to scrutiny and enquiry. Science sets out to reveal and explain our reality, whereas art comments and makes connections that don't need to be tested by rigorous protocols. Art and science should each be evaluated on their own merit. Allowing room for both in the quest to understand our world will lead to an enriched experience.

  15. Stroboscopic Image Modulation to Reduce the Visual Blur of an Object Being Viewed by an Observer Experiencing Vibration

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K. (Inventor); Adelstein, Bernard D. (Inventor); Anderson, Mark R. (Inventor); Beutter, Brent R. (Inventor); Ahumada, Albert J., Jr. (Inventor); McCann, Robert S. (Inventor)

    2014-01-01

    A method and apparatus for reducing the visual blur of an object being viewed by an observer experiencing vibration. In various embodiments of the present invention, the visual blur is reduced through stroboscopic image modulation (SIM). A SIM device is operated in an alternating "on/off" temporal pattern according to a SIM drive signal (SDS) derived from the vibration being experienced by the observer. A SIM device (controlled by a SIM control system) operates according to the SDS serves to reduce visual blur by "freezing" (or reducing an image's motion to a slow drift) the visual image of the viewed object. In various embodiments, the SIM device is selected from the group consisting of illuminator(s), shutter(s), display control system(s), and combinations of the foregoing (including the use of multiple illuminators, shutters, and display control systems).

  16. The complete visual light curve of SN 1987A: Thirteen months of FES observations. [IUE Fine Error Sensor (FES)

    NASA Technical Reports Server (NTRS)

    Sonneborn, G.

    1988-01-01

    Visual brightness measurements of SN 1987A are being obtained with the IUE acquisition camera and star tracker Fine Error Sensor, (FES) as part of each ultraviolet observation. Due to IUE's around-the-clock operation and lack of clouds, the FES record of SN 1987A provides the most complete set of visual photometry of the supernova made by any single instrument. The data illustrate the photometric limitations of the FES (+ or - 0.03 mag). Use of differential photometric methods are recommended for IUE observers desiring accurate photometry from FES measurements made during their observing shifts.

  17. Observation, Assisting, Apprenticeship: Cycles of Visual and Kinesthetic Learning in Dental Education

    PubMed Central

    Horst, Jeremy A.; Clark, Matthew D.; Lee, Andrew H.

    2009-01-01

    Dentists are self-selected for visual and kinesthetic learning preferences. Watching another practitioner perform treatment can be incredibly didactic, both before and after learning the procedure. This missing part of dental education has the capacity to play a tremendous role in dental education for all levels of practitioner. Dental students in their clinical years begin to realize the meaning of dentistry as a practice, a set of skills that are never perfected. Abundant evidence demonstrates that cycling between observation and practice enhances procedural learning and retention, yet this mechanism is vastly underused in dental education. Collaborative treatment paradigms, wherein the able student assists a more experienced practitioner, can create mentorship. Learning potentially esoteric information or subtle nuances of clinical acumen is facilitated by the contextual framework of the clinical environment and is strengthened by emotional attachments through interpersonal interactions. In this article, we explore the evidence surrounding mentorship and clinical observation both before and after students are given the responsibilities of patient care, which together recapitulate clinical apprenticeship. Finally, we present examples of how apprenticeship can be brought back to dental education, including evaluation of a clinical assisting program that we implemented and explanation of a hypothetical faculty-student practice partnership model. PMID:19648563

  18. Comparing masked target transform volume (MTTV) clutter metric to human observer evaluation of visual clutter

    NASA Astrophysics Data System (ADS)

    Camp, H. A.; Moyer, Steven; Moore, Richard K.

    2010-04-01

    The Night Vision and Electronic Sensors Directorate's current time-limited search (TLS) model, which makes use of the targeting task performance (TTP) metric to describe image quality, does not explicitly account for the effects of visual clutter on observer performance. The TLS model is currently based on empirical fits to describe human performance for a time of day, spectrum and environment. Incorporating a clutter metric into the TLS model may reduce the number of these empirical fits needed. The masked target transform volume (MTTV) clutter metric has been previously presented and compared to other clutter metrics. Using real infrared imagery of rural images with varying levels of clutter, NVESD is currently evaluating the appropriateness of the MTTV metric. NVESD had twenty subject matter experts (SME) rank the amount of clutter in each scene in a series of pair-wise comparisons. MTTV metric values were calculated and then compared to the SME observers rankings. The MTTV metric ranked the clutter in a similar manner to the SME evaluation, suggesting that the MTTV metric may emulate SME response. This paper is a first step in quantifying clutter and measuring the agreement to subjective human evaluation.

  19. Overland flow dynamics through visual observation using time-lapse photographs

    NASA Astrophysics Data System (ADS)

    Silasari, Rasmiaditya; Blöschl, Günter

    2016-04-01

    Overland flow process on agricultural land is important to be investigated as it affects the stream discharge and water quality assessment. During rainfall events the formation of overland flow may happen through different processes (i.e. Hortonian or saturation excess overland flow) based on the governing soil hydraulic parameters (i.e. soil infiltration rate, soil water capacity). The dynamics of the soil water state and the processes will affect the surface runoff response which can be analyzed visually by observing the saturation patterns with a camera. Although visual observation was proven useful in laboratory experiments, the technique is not yet assessed for natural rainfall events. The aim of this work is to explore the use of time-lapse photographs of naturally occurring-saturation patterns in understanding the threshold processes of overland flow generation. The image processing produces orthographic projection of the saturation patterns which will be used to assess the dynamics of overland flow formation in relation with soil moisture state and rainfall magnitude. The camera observation was performed at Hydrological Open Air Laboratory (HOAL) catchment at Petzenkirchen, Lower Austria. The catchment covers an area of 66 ha dominated with agricultural land (87%). The mean annual precipitation and mean annual flow at catchment outlet are 750 mm and 4 l/s, respectively. The camera was set to observe the overland flow along a thalweg on an arable field which was drained in 1950s and has advantages of: (1) representing agricultural land as the dominant part of the catchment, (2) adjacent to the stream with clear visibility (no obstructing objects, such as trees), (3) drained area provides extra cases in understanding the response of tile drain outflow to overland flow formation and vice versa, and (4) in the vicinity of TDT soil moisture stations. The camera takes a picture with 1280 x 720 pixels resolution every minute and sends it directly in a PC via fiber

  20. Request for additional epsilon Aurigae observations

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-10-01

    Dr. Robert Stencel (Denver U.) requests enhanced coverage of the bright, long-period eclipsing binary star epsilon Aurigae through Wednesday. Observations are requested beginning immediately (October 29, 2009; JD 2455134) and continuing through November 5, 2009 (JD 2455141). This request is in conjunction with scheduled observations with the CHARA optical interferometer at Mount Wilson in California. Optical photometry by a number of observers will provide a continuous photometric baseline of epsilon Aurigae during the course of the interferometry, enabling Stencel and collaborators to more easily interpret the interferometric images. These interferometric observations are being made to image the system as it enters eclipse; the optical interferometric observations being made by CHARA are completely analogous to those made with radio interferometers like the Very Large Array, and allow ground based observers to obtain images with far higher resolution than a single optical telescope is capable of. The CHARA observations are scheduled for the nights of November 1, 2, and 3 (through mid-day UT on November 4, 2009). All observations, including visual estimates, DSLR and CCD photometry, and photoelectric photometry, are encouraged. The observations are part of a larger, long-term collaborative effort to study epsilon Aurigae. For more information on epsilon Aurigae, see the Citizen Sky website http://www.citizensky.org/. Epsilon Aurigae is currently in the ingress phase of the eclipse, which likely began in August of 2009. The star is now near V ~ 3.4 and declining. The nature of the eclipsing object is not known, but is likely to be an opaque disk surrounding an unseen, massive secondary star or binary pair. Interferometric images of epsilon Aurigae may yield strong constraints on the shape of the eclipsing! disk and size of the system. Observations should be reported to the AAVSO International Database as EPS AUR.

  1. Expanding biological data standards development processes for US IOOS: visual line transect observing community for mammal, bird, and turtle data

    USGS Publications Warehouse

    Fornwall, M.; Gisiner, R.; Simmons, S. E.; Moustahfid, Hassan; Canonico, G.; Halpin, P.; Goldstein, P.; Fitch, R.; Weise, M.; Cyr, N.; Palka, D.; Price, J.; Collins, D.

    2012-01-01

    The US Integrated Ocean Observing System (IOOS) has recently adopted standards for biological core variables in collaboration with the US Geological Survey/Ocean Biogeographic Information System (USGS/OBIS-USA) and other federal and non-federal partners. In this Community White Paper (CWP) we provide a process to bring into IOOS a rich new source of biological observing data, visual line transect surveys, and to establish quality data standards for visual line transect observations, an important source of at-sea bird, turtle and marine mammal observation data. The processes developed through this exercise will be useful for other similar biogeographic observing efforts, such as passive acoustic point and line transect observations, tagged animal data, and mark-recapture (photo-identification) methods. Furthermore, we suggest that the processes developed through this exercise will serve as a catalyst for broadening involvement by the larger marine biological data community within the goals and processes of IOOS.

  2. Visualizing preparation using asymmetrical choline-like ionic liquids for scanning electron microscope observation of non-conductive biological samples.

    PubMed

    Abe, Shigeaki; Hyono, Atsushi; Kawai, Koji; Yonezawa, Tetsu

    2014-03-01

    In this study, we investigated conductivity preparation for scanning electron microscope (SEM) observation that used novel asymmetrical choline-type room temperature ionic liquids (RTIL). By immersion in only an RTIL solution, clear SEM images of several types of biological samples were successfully observed. In addition, we could visualize protozoans using RTILs without any dilution. These results suggested that the asymmetrical choline-type RTILs used in this study are suitable for visualizing of biological samples by SEM. Treatment without the need for dilution can obviate the need for adjusting the RTIL concentration and provide for a rapid and easy conductivity treatment for insulating samples.

  3. Human observers have optimal introspective access to perceptual processes even for visually masked stimuli

    PubMed Central

    Peters, Megan A K; Lau, Hakwan

    2015-01-01

    Many believe that humans can ‘perceive unconsciously’ – that for weak stimuli, briefly presented and masked, above-chance discrimination is possible without awareness. Interestingly, an online survey reveals that most experts in the field recognize the lack of convincing evidence for this phenomenon, and yet they persist in this belief. Using a recently developed bias-free experimental procedure for measuring subjective introspection (confidence), we found no evidence for unconscious perception; participants’ behavior matched that of a Bayesian ideal observer, even though the stimuli were visually masked. This surprising finding suggests that the thresholds for subjective awareness and objective discrimination are effectively the same: if objective task performance is above chance, there is likely conscious experience. These findings shed new light on decades-old methodological issues regarding what it takes to consider a neurobiological or behavioral effect to be 'unconscious,' and provide a platform for rigorously investigating unconscious perception in future studies. DOI: http://dx.doi.org/10.7554/eLife.09651.001 PMID:26433023

  4. Visually observed mold and moldy odor versus quantitatively measured microbial exposure in homes.

    PubMed

    Reponen, Tiina; Singh, Umesh; Schaffer, Chris; Vesper, Stephen; Johansson, Elisabet; Adhikari, Atin; Grinshpun, Sergey A; Indugula, Reshmi; Ryan, Patrick; Levin, Linda; Lemasters, Grace

    2010-10-15

    The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children's asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child's age 1 (Year 1). Similar assessment supplemented with air sampling was conducted in Year 7. Samples were analyzed for endotoxin, (1-3)-β-D-glucan, and fungal spores. The Mold Specific Quantitative Polymerase Chain Reaction assay was used to analyze 36 mold species in dust samples, and the Environmental Relative Moldiness Index (ERMI) was calculated. Homes were categorized based on three criteria: 1) visible mold damage, 2) moldy odor, and 3) ERMI. Even for homes where families had not moved, Year 7 endotoxin and (1-3)-β-d-glucan exposures were significantly higher than those in Year 1 (p<0.001), whereas no difference was seen for ERMI (p=0.78). Microbial concentrations were not consistently associated with visible mold damage categories, but were consistently higher in homes with moldy odor and in homes that had high ERMI. Low correlations between results in air and dust samples indicate different types or durations of potential microbial exposures from dust vs. air. Future analysis will indicate which, if any, of the assessment methods is associated with the development of asthma.

  5. Visually observed mold and moldy odor versus quantitatively measured microbial exposure in homes

    PubMed Central

    Reponen, Tiina; Singh, Umesh; Schaffer, Chris; Vesper, Stephen; Johansson, Elisabet; Adhikari, Atin; Grinshpun, Sergey A.; Indugula, Reshmi; Ryan, Patrick; Levin, Linda; LeMasters, Grace

    2010-01-01

    The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children’s asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child’s age 1 (Year 1). Similar assessment supplemented with air sampling was conducted in Year 7. Samples were analyzed for endotoxin, (1–3)-β-D-glucan, and fungal spores. The Mold Specific Quantitative Polymerase Chain Reaction assay was used to analyze 36 mold species in dust samples, and the Environmental Relative Moldiness Index (ERMI) was calculated. Homes were categorized based on three criteria: 1) visible mold damage, 2) moldy odor, and 3) ERMI. Even for homes where families had not moved, Year 7 endotoxin and (1–3)-β-D-glucan exposures were significantly higher than those in Year 1 (p<0.001), whereas no difference was seen for ERMI (p=0.78). Microbial concentrations were not consistently associated with visible mold damage categories, but were consistently higher in homes with moldy odor and in homes that had high ERMI. Low correlations between results in air and dust samples indicate different types or durations of potential microbial exposures from dust vs. air. Future analysis will indicate which, if any, of the assessment methods is associated with the development of asthma. PMID:20810150

  6. Thermal infrared and visual observations of a water ice lag in the Mars southern summer

    USGS Publications Warehouse

    Titus, T.N.

    2005-01-01

    We present thermal infrared and visual evidence for the existence of water ice lags in the early southern summer. The observed H2O-ice lags lay in and near a chasma and appears to survive between 6-8 sols past the sublimation of the CO2. Possible sources of the H2O that compose the lag are (1) atmospheric H2O that is incorporated into the seasonal cap during condensation, (2) cold trapping of atmospheric water vapor onto the surface of the cap in the spring, or (3) a combination of the 2 processes where water is released from the sublimating cap only to be transported back over the cap edge and cold trapped. We refer to this later process as the "Houben" effect which may enrich the amount of water contained in the seasonal cap at 85??S by as much as a factor of 15. This phenomenon, which has already been identified for the northern retreating cap, may present an important water transport mechanism in the Southern Hemisphere.

  7. United States Naval Academy Polar Science Program's Visual Arctic Observing Buoys; The IceGoat

    NASA Astrophysics Data System (ADS)

    Woods, J. E.; Clemente-Colon, P.; Nghiem, S. V.; Rigor, I.; Valentic, T. A.

    2012-12-01

    The U.S. Naval Academy Oceanography Department currently has a curriculum based Polar Science Program (USNA PSP). Within the PSP there is an Arctic Buoy Program (ABP) student research component that will include the design, build, testing and deployment of Arctic Buoys. Establishing an active, field-research program in Polar Science will greatly enhance Midshipman education and research, as well as introduce future Naval Officers to the Arctic environment. The Oceanography Department has engaged the USNA Ocean Engineering, Systems Engineering, Aerospace Engineering, and Computer Science Departments and developed a USNA Visual Arctic Observing Buoy, IceGoat1, which was designed, built, and deployed by midshipmen. The experience gained through Polar field studies and data derived from these buoys will be used to enhance course materials and laboratories and will also be used directly in Midshipman independent research projects. The USNA PSP successfully deployed IceGoat1 during the BROMEX 2012 field campaign out of Barrow, AK in March 2012. This buoy reports near real-time observation of Air Temperature, Sea Temperature, Atmospheric Pressure, Position and Images from 2 mounted webcams. The importance of this unique type of buoy being inserted into the U.S. Interagency Arctic Buoy Program and the International Arctic Buoy Programme (USIABP/IABP) array is cross validating satellite observations of sea ice cover in the Arctic with the buoys webcams. We also propose to develop multiple sensor packages for the IceGoat to include a more robust weather suite, and a passive acoustic hydrophone. Remote cameras on buoys have provided crucial qualitative information that complements the quantitative measurements of geophysical parameters. For example, the mechanical anemometers on the IABP Polar Arctic Weather Station at the North Pole Environmental Observatory (NPEO) have at times reported zero winds speeds, and inspection of the images from the NPEO cameras have showed

  8. Prospective, observational study comparing automated and visual point-of-care urinalysis in general practice

    PubMed Central

    van Delft, Sanne; Goedhart, Annelijn; Spigt, Mark; van Pinxteren, Bart; de Wit, Niek; Hopstaken, Rogier

    2016-01-01

    Objective Point-of-care testing (POCT) urinalysis might reduce errors in (subjective) reading, registration and communication of test results, and might also improve diagnostic outcome and optimise patient management. Evidence is lacking. In the present study, we have studied the analytical performance of automated urinalysis and visual urinalysis compared with a reference standard in routine general practice. Setting The study was performed in six general practitioner (GP) group practices in the Netherlands. Automated urinalysis was compared with visual urinalysis in these practices. Reference testing was performed in a primary care laboratory (Saltro, Utrecht, The Netherlands). Primary and secondary outcome measures Analytical performance of automated and visual urinalysis compared with the reference laboratory method was the primary outcome measure, analysed by calculating sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) and Cohen's κ coefficient for agreement. Secondary outcome measure was the user-friendliness of the POCT analyser. Results Automated urinalysis by experienced and routinely trained practice assistants in general practice performs as good as visual urinalysis for nitrite, leucocytes and erythrocytes. Agreement for nitrite is high for automated and visual urinalysis. κ's are 0.824 and 0.803 (ranked as very good and good, respectively). Agreement with the central laboratory reference standard for automated and visual urinalysis for leucocytes is rather poor (0.256 for POCT and 0.197 for visual, respectively, ranked as fair and poor). κ's for erythrocytes are higher: 0.517 (automated) and 0.416 (visual), both ranked as moderate. The Urisys 1100 analyser was easy to use and considered to be not prone to flaws. Conclusions Automated urinalysis performed as good as traditional visual urinalysis on reading of nitrite, leucocytes and erythrocytes in routine general practice. Implementation of automated

  9. Observability Analysis of a Matrix Kalman Filter-Based Navigation System Using Visual/Inertial/Magnetic Sensors

    PubMed Central

    Feng, Guohu; Wu, Wenqi; Wang, Jinling

    2012-01-01

    A matrix Kalman filter (MKF) has been implemented for an integrated navigation system using visual/inertial/magnetic sensors. The MKF rearranges the original nonlinear process model in a pseudo-linear process model. We employ the observability rank criterion based on Lie derivatives to verify the conditions under which the nonlinear system is observable. It has been proved that such observability conditions are: (a) at least one degree of rotational freedom is excited, and (b) at least two linearly independent horizontal lines and one vertical line are observed. Experimental results have validated the correctness of these observability conditions. PMID:23012523

  10. Observability analysis of a matrix Kalman filter-based navigation system using visual/inertial/magnetic sensors.

    PubMed

    Feng, Guohu; Wu, Wenqi; Wang, Jinling

    2012-01-01

    A matrix Kalman filter (MKF) has been implemented for an integrated navigation system using visual/inertial/magnetic sensors. The MKF rearranges the original nonlinear process model in a pseudo-linear process model. We employ the observability rank criterion based on Lie derivatives to verify the conditions under which the nonlinear system is observable. It has been proved that such observability conditions are: (a) at least one degree of rotational freedom is excited, and (b) at least two linearly independent horizontal lines and one vertical line are observed. Experimental results have validated the correctness of these observability conditions.

  11. Visual estimates of brightness and analysis of observations of variable stars

    NASA Technical Reports Server (NTRS)

    Tsesevich, V. P.

    1973-01-01

    Methods of visual estimation of the brightness of variable stars include the Argelander method, Pickering method, and Neyland-Blazhko method. Systematic errors are discussed together with methods of plotting brightness curves.

  12. Rey's 15-Item Visual Memory Test for the Detection of Malingering: Normative Observations on Patients with Neurological Disorders.

    ERIC Educational Resources Information Center

    Lee, Gregory P.; And Others

    1992-01-01

    To gather normative observations on a visual memory test developed by A. Rey (1964), it was administered to 100 temporal-lobe epilepsy patients with memory deficits and 56 outpatients with neurological disorders. Results suggest a cutoff score of 7 on the memory test may alert the clinician to possible factitious memory complaints. (SLD)

  13. The Influence of a Crosshair Visual Aid on Observer Detection of Simulated Fetal Heart Rate Signals.

    PubMed

    Kennedy, Rebecca A; Scerbo, Mark W; Anderson-Montoya, Brittany L; Belfore, Lee A; Abuhamad, Alfred Z; Davis, Stephen S

    2016-03-01

    Objective To determine whether a visual aid overlaid on fetal heart rate (FHR) tracings increases detection of critical signals relative to images with no visual aid. Study Design In an experimental study, 21 undergraduate students viewed 240 images of simulated FHR tracings twice, once with the visual aids and once without aids. Performance was examined for images containing three different types of FHR signals (early deceleration, late deceleration, and acceleration) and four different FHR signal-to-noise ratios corresponding to FHR variability types (absent, minimal, moderate, and marked) identified by the National Institute of Child Health and Human Development (2008). Performance was analyzed using repeated-measures analyses of variance. Results The presence of the visual aid significantly improved correct detections of signals overall and decreased false alarms for the marked variability condition. Conclusion The results of the study provide evidence that the presence of a visual aid was useful in helping novices identify FHR signals in simulated maternal-fetal heart rate images. Further, the visual aid was most useful for conditions in which the signal is most difficult to detect (when FHR variability is highest).

  14. The Influence of a Crosshair Visual Aid on Observer Detection of Simulated Fetal Heart Rate Signals.

    PubMed

    Kennedy, Rebecca A; Scerbo, Mark W; Anderson-Montoya, Brittany L; Belfore, Lee A; Abuhamad, Alfred Z; Davis, Stephen S

    2016-03-01

    Objective To determine whether a visual aid overlaid on fetal heart rate (FHR) tracings increases detection of critical signals relative to images with no visual aid. Study Design In an experimental study, 21 undergraduate students viewed 240 images of simulated FHR tracings twice, once with the visual aids and once without aids. Performance was examined for images containing three different types of FHR signals (early deceleration, late deceleration, and acceleration) and four different FHR signal-to-noise ratios corresponding to FHR variability types (absent, minimal, moderate, and marked) identified by the National Institute of Child Health and Human Development (2008). Performance was analyzed using repeated-measures analyses of variance. Results The presence of the visual aid significantly improved correct detections of signals overall and decreased false alarms for the marked variability condition. Conclusion The results of the study provide evidence that the presence of a visual aid was useful in helping novices identify FHR signals in simulated maternal-fetal heart rate images. Further, the visual aid was most useful for conditions in which the signal is most difficult to detect (when FHR variability is highest). PMID:26989564

  15. The USNO 26'' Clark Refractor; From Visual Observations to Speckle Interferometry

    NASA Astrophysics Data System (ADS)

    Bartlett, Jennifer L.; Mason, B. D.; Hartkopf, W. I.

    2011-01-01

    Before addressing queries about how and what to preserve among astronomical devices, the question of what constitutes a historic instrument must be considered. Certainly, the lenses are the defining feature of a Clark refractor. Since 1867, when Newcomb inquired about the possibility of obtaining a great glass from Alvan Clark & Sons, the U.S. Naval Observatory 26-in (66-cm) equatorial has evolved in response to improvements in technology and changes in its observing program. After two major overhauls, only the objective remains of the equipment originally installed by the Clarks in 1873 at the old Observatory site in Foggy Bottom. However, the telescope retains its reputation as a historic Clark refractor. The USNO telescope was briefly renowned as the largest refractor in the world; the second of five such achievements by the Clarks. Through it, Hall first detected the moons of Mars in 1877. However, by that time, the Clarks had already refigured the flint glass. Hall and Gardiner had also altered the drive mechanism. When the USNO moved to its present Georgetown Heights location in 1893, the great equatorial was refurbished with its original Clark optics installed on a more robust Warner & Swasey mount. Peters eventually incorporated discarded parts from the original mounting into his photographic telescopes during the first half of the 20th century. The 26'' refractor underwent further modernization in the early 1960s to facilitate the xy-slide of a Hertzsprung-style photographic double star camera. In 1965, the objective was disassembled for cleaning and reassembled with new spacers. The most recent maintenance included re-wiring and replacing several motors and the hand paddles. Originally designed as a visual instrument, the USNO 26'' Clark refractor now hosts a speckle interferometer for its current double star program. Despite continuing modifications, this telescope remains a fine example of the optician's art.

  16. AG Dra monitoring requested for multiwavelength campaign

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-06-01

    Dr. Andrea Dupree (Harvard-Smithsonian Center for Astrophysics) has requested AAVSO monitoring (visual and photometric) of the symbiotic variable AG Draconis from June 20 through at least September 2013 for correlation with upcoming Chandra x-ray and HST ultraviolet observations. The purpose of their observations is to determine the dynamics of the gas and the temperatures and densities in various parts of this complex system. Finder charts with sequences may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database.

  17. Observations of the eclipsing binary b Persei

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2015-01-01

    Dr. Robert Zavala (USNO-Flagstaff) et al. request V time-series observations of the bright variable star b Persei 7-21 January 2015 UT, in hopes of catching a predicted eclipse on January 15. This is a follow-up to the February 2013 campaign announced in Alert Notice 476, and will be used as a photometric comparison for upcoming interferometric observations with the Navy Precision Optical Interferometer (NPOI) in Arizona. b Per (V=4.598, B-V=0.054) is ideal for photoelectric photometers or DSLR cameras. Telescopic CCD observers may observe by stopping down larger apertures. Comparison and check stars assigned by PI: Comp: SAO 24412, V=4.285, B-V = -0.013; Check: SAO 24512, V=5.19, B-V = -0.05. From the PI: "[W]e wanted to try and involve AAVSO observers in a follow up to our successful detection of the b Persei eclipse of Feb 2013, AAVSO Alert Notice 476 and Special Notice 333. Our goal now is to get good time resolution photometry as the third star passes in front of the close ellipsoidal binary. The potential for multiple eclipses exists. The close binary has a 1.5 day orbital period, and the eclipsing C component requires about 4 days to pass across the close binary pair. The primary eclipse depth is 0.15 magnitude. Photometry to 0.02 or 0.03 mags would be fine to detect this eclipse. Eclipse prediction date (JD 2457033.79 = 2015 01 11 UT, ~+/- 1 day) is based on one orbital period from the 2013 eclipse." More information is available at PI's b Persei eclipse web page: http://inside.warren-wilson.edu/~dcollins/bPersei/. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and information on the targets.

  18. Object visibility alters the relative contribution of ventral visual stream and mirror neuron system to goal anticipation during action observation.

    PubMed

    Thioux, Marc; Keysers, Christian

    2015-01-15

    We used fMRI to study the effect of hiding the target of a grasping action on the cerebral activity of an observer whose task was to anticipate the size of the object being grasped. Activity in the putative mirror neuron system (pMNS) was higher when the target was concealed from the view of the observer and anticipating the size of the object being grasped requested paying attention to the hand kinematics. In contrast, activity in ventral visual areas outside the pMNS increased when the target was fully visible, and the performance improved in this condition. A repetition suppression analysis demonstrated that in full view, the size of the object being grasped by the actor was encoded in the ventral visual stream. Dynamic causal modeling showed that monitoring a grasping action increased the coupling between the parietal and ventral premotor nodes of the pMNS. The modulation of the functional connectivity between these nodes was correlated with the subject's capability to detect the size of hidden objects. In full view, synaptic activity increased within the ventral visual stream, and the connectivity with the pMNS was diminished. The re-enactment of observed actions in the pMNS is crucial when interpreting others' actions requires paying attention to the body kinematics. However, when the context permits, visual-spatial information processing may complement pMNS computations for improved action anticipation accuracy.

  19. A Summary Comparison of Active Acoustic Detections and Visual Observations of Marine Mammals in the Canadian Beaufort Sea.

    PubMed

    Pyć, Cynthia D; Geoffroy, Maxime; Knudsen, Frank R

    2016-01-01

    Fisheries sonar was used to determine the applicability of active acoustic monitoring (AAM) for marine mammal detection in the Canadian Beaufort Sea. During 170 h of simultaneous observation by marine mammal observers and active acoustic observation, 119 Balaena mysticetus (bowheads) and 4 Delphinapterus leucas (belugas) were visually sighted, while 59 acoustic signals of bowheads were detected by AAM operators. Observations and detection of seals were also recorded. Comparative results indicate that commercially available active acoustic systems can detect seals at distances up to 500 m and large baleen whales at distances up to 2 km.

  20. A Summary Comparison of Active Acoustic Detections and Visual Observations of Marine Mammals in the Canadian Beaufort Sea.

    PubMed

    Pyć, Cynthia D; Geoffroy, Maxime; Knudsen, Frank R

    2016-01-01

    Fisheries sonar was used to determine the applicability of active acoustic monitoring (AAM) for marine mammal detection in the Canadian Beaufort Sea. During 170 h of simultaneous observation by marine mammal observers and active acoustic observation, 119 Balaena mysticetus (bowheads) and 4 Delphinapterus leucas (belugas) were visually sighted, while 59 acoustic signals of bowheads were detected by AAM operators. Observations and detection of seals were also recorded. Comparative results indicate that commercially available active acoustic systems can detect seals at distances up to 500 m and large baleen whales at distances up to 2 km. PMID:26611045

  1. Gravity and observer's body orientation influence the visual perception of human body postures.

    PubMed

    Lopez, Christophe; Bachofner, Christelle; Mercier, Manuel; Blanke, Olaf

    2009-05-04

    Since human behavior and perception have evolved within the Earth's gravitational field, humans possess an internal model of gravity. Although gravity is known to influence the visual perception of moving objects, the evidence is less clear concerning the visual perception of static objects. We investigated whether a visual judgment of the stability of human body postures (static postures of a human standing on a platform and tilted in the roll plane) may also be influenced by gravity and by the participant's orientation. Pictures of human body postures were presented in different orientations with respect to gravity and the participant's body. The participant's body was aligned to gravity (upright) or not (lying on one side). Participants performed stability judgments with respect to the platform, imagining that gravity operates in the direction indicated by the platform (that was or was not concordant with physical gravity). Such visual judgments were influenced by the picture's orientation with respect to physical gravity. When pictures were tilted by 90 degrees with respect to physical gravity, the human postures that were tilted toward physical gravity (down) were perceived as more unstable than similar postures tilted away from physical gravity (up). Stability judgments were also influenced by the picture's orientation with respect to the participant's body. This indicates that gravity and the participant's body position may influence the visual perception of static objects.

  2. Earth Science Observations, Analysis and Visualization: Roots in the 60's - Vision for the Next Millennium

    NASA Technical Reports Server (NTRS)

    Hasler, A. Fritz; Allen, Jesse

    1999-01-01

    The Etheater presents visualizations which span the period from the original Suomi/Hasler animations of the first ATS-1 GEO weather satellite images in 1966....... to the latest 1999 NASA Earth Science Vision for the next 25 years. Hot off the SGI-Onyx Graphics-Supercomputer are NASA's visualizations of Hurricanes Mitch, Georges, Fran and Linda. These storms have been recently featured on the covers of National Geographic, Time, Newsweek and Popular Science. Highlights will be shown from the NASA hurricane visualization resource video tape in standard and HDTV that has been used repeatedly this season on National and International network TV. Results will be presented from a new paper on automatic wind measurements in Hurricane Luis from 1-min GOES images that appeared in the November BAMS.

  3. Earth Science Observations, Analysis and Visualization: Roots in the 60's: Vision for the Next Millennium

    NASA Technical Reports Server (NTRS)

    Hasler, A. F.

    1999-01-01

    The Etheater presents visualizations which span the period from the original Suomi/Hasler animations of the first ATS-1 GEO weather satellite images in 1966 ... to the latest 1999 NASA Earth Science Vision for the next 25 years. Hot off the SGI-Onyx Graphics-Supercomputer are NASA's visualizations of Hurricanes Mitch, Georges, Fran and Linda. These storms have been recently featured on the covers of National Geographic, Time, Newsweek and Popular Science. Highlights will be shown from the NASA hurricane visualization resource video tape that has been used repeatedly this season on National and International network TV. Results will be presented from a new paper on automatic wind measurements in Hurricane Luis from 1-min GOES images that appeared in the November BAMS.

  4. Observing degradation of visual representations over short intervals when MTL is damaged

    PubMed Central

    Warren, David E.; Duff, Melissa C.; Tranel, Daniel; Cohen, Neal J.

    2012-01-01

    Medial temporal lobe (MTL) contributions to the brief maintenance of visual representations were evaluated by studying a group of patients with MTL damage. Eye movements of patients and healthy comparison subjects were tracked while performing a visual search for a target among complex stimuli of varying similarity to that target. Despite the task having no imposed delays, patients were impaired behaviorally, and eye-movement measures showed abnormally rapid degradation of target representations in the patients. Eye-movement data showed a modulation of the duration of fixations as a function of the similarity of fixated array lures to the target, but the effect was attenuated in patients during long fixation paths away from the sample target. This effect manifested despite patients’ shorter searches and more frequent fixations of the sample target. Novel techniques provided unique insight into visual representation without healthy MTL, which may support maintenance of information through hippocampal-dependent relational binding. PMID:21736458

  5. Visualizing Earth's Erupting Volcanoes and Wildfires: Seven Years of Data From the Earth Observing Mission

    NASA Astrophysics Data System (ADS)

    Wright, R.; Pilger, E.; Flynn, L. P.; Harris, A. J.

    2006-12-01

    Volcanic eruptions and wildfires are natural hazards that are truly global in their geographic scope, as well as being temporally very dynamic. As such, satellite remote sensing lends itself to their effective detection and monitoring. The results of such mapping can be communicated in the form of traditional static maps. However, most hazards have strong time-dependent forcing mechanisms (in the case of biomass burning, climate) and the dynamism of these geophysical phenomena requires a suitable method for their presentation. Here, we present visualizations of the amount of thermal energy radiated by all of Earth's sub-aerially erupting volcanoes, wildfires and industrial heat sources over a seven year period. These visualizations condense the results obtained from the near-real-time analysis of over 1.2 million MODIS (Moderate Resolution Imaging Spectro-radiometer) images, acquired from NASA's Terra and Aqua platforms. In the accompanying poster we will describe a) the raw data, b) how these data can be used to derive higher-order geophysical parameters, and c) how the visualization of these derived products adds scientific value to the raw data. The visualizations reveal spatio-temporal trends in fire radiated energy (and by proxy, biomass combustion rates and carbon emissions into the atmosphere), which are indiscernible in the static data set. Most notable are differences in biomass combustion between the North American and Eurasian Boreal forests. We also give examples relating to the development of lava flow-fields at Mount Etna (Italy) and Kilauea (USA), as well as variations in heat output from Iraqi oil fields, that span the onset of the 2003 Persian Gulf War. The raw data used to generate these visualizations are routinely made available via the Internet, as portable ASCII files. They can therefore be easily integrated with image datasets, by other researchers, to create their own visualizations.

  6. Visualization of HDF/HDF-EOS Format Earth Observing System Data Using the ISIS "cv" Program

    NASA Astrophysics Data System (ADS)

    Torson, J. M.

    2001-05-01

    The "cv" (Cube Visualization) program has been used for a number of years as part of the ISIS image processing system (Integrated Software for Imagers and Spectrometers) [1],[2]. In addition to reading the native ISIS image cube format, "cv" has recently been enhanced to directly read the HDF and HDF-EOS file formats used for distributing data from various Earth Observing System (EOS) Missions (e.g. the Terra and Landsat-7 satellites). Files based on HDF Version 4.x are supported; files based on the new HDF 5.x are not yet supported. "cv" is now packaged so that it can be used without installing the rest of the ISIS software system. The capabilities of the program include: Displays (as images) any Swath/Grid data fields in HDF-EOS files; Displays (as images) any Scientific Data Set (SDS) data fields in HDF files; Combines multiple HDF/HDF-EOS fields to form one display object; Subarea selection and/or subsampling (allows handling large files); Simultaneous display of multiple images/files; Plots intensity profiles along any of the three axes in a 3D data set; Writes displayed data fields to binary files (allows doing further processing using ISIS programs or using other software packages); Reports cursor location and pixel value (includes reporting Latitude/Longitude with optional conversion between geocentric and geographic coordinates); Includes many additional flexible display options. The "cv" program is implemented in the IDL language and makes use of the IDL CALL_EXTERNAL capability to call I/O and utility routines written in C and Fortran. Pre-compiled versions of "cv" are available for Sun Solaris, Compaq Alpha and PC Linux platforms. To obtain "cv", go to the USGS anonymous ftp site (ftpflag.wr.usgs.gov). Do a "cd dist/isis" and get (in binary mode) the README_CV.TXT file (installation instructions) and the tar file for the desired platform (cv_sun.tar, cv_alpha.tar, cv_pc.tar). More information on ISIS is available at the ISIS website (http

  7. Visual Contrast Sensitivity Functions Obtained from Untrained Observers Using Tracking and Staircase Procedures. Final Report.

    ERIC Educational Resources Information Center

    Geri, George A.; Hubbard, David C.

    Two adaptive psychophysical procedures (tracking and "yes-no" staircase) for obtaining human visual contrast sensitivity functions (CSF) were evaluated. The procedures were chosen based on their proven validity and the desire to evaluate the practical effects of stimulus transients, since tracking procedures traditionally employ gradual stimulus…

  8. Visual dysfunction and its correlation with retinal changes in patients with Parkinson's disease: an observational cross-sectional study

    PubMed Central

    Polo, V; Satue, M; Rodrigo, M J; Otin, S; Alarcia, R; Bambo, M P; Fuertes, M I; Larrosa, J M; Pablo, L E; Garcia-Martin, E

    2016-01-01

    Objectives To evaluate visual dysfunction and its correlation with structural changes in the retina in patients with Parkinson's disease (PD). Methods Patients with PD (n=37) and controls (n=37) were included in an observational cross-sectional study, and underwent visual acuity (VA), colour vision (using the Farnsworth and Lanthony desaturated D15 colour tests) and contrast sensitivity vision (CSV; using the Pelli-Robson chart and CSV 1000E test) evaluation to measure visual dysfunction. Structural measurements of the retinal nerve fibre layer (RNFL), and macular and ganglion cell layer (GCL) thicknesses, were obtained using spectral domain optical coherence tomography (SD-OCT). Comparison of obtained data, and correlation analysis between functional and structural results were performed. Results VA (in all different contrast levels) and all CSV spatial frequencies were significantly worse in patients with PD than in controls. Colour vision was significantly affected based on the Lanthony colour test. Significant GCL loss was observed in the minimum GCL+inner plexiform layer. A clear tendency towards a reduction in several macular sectors (central, outer inferior, outer temporal and superior (inner and outer)) and in the temporal quadrant of the RNFL thickness was observed, although the difference was not significant. CSV was the functional parameter most strongly correlated with structural measurements in PD. Colour vision was associated with most GCL measurements. Macular thickness was strongly correlated with macular volume and functional parameters (r>0.70, p<0.05). Conclusions Patients with PD had visual dysfunction that correlated with structural changes evaluated by SD-OCT. GCL measurements may be reliable indicators of visual impairment in patients with PD. PMID:27154474

  9. What visual illusions tell us about underlying neural mechanisms and observer strategies for tackling the inverse problem of achromatic perception

    PubMed Central

    Blakeslee, Barbara; McCourt, Mark E.

    2015-01-01

    Research in lightness perception centers on understanding the prior assumptions and processing strategies the visual system uses to parse the retinal intensity distribution (the proximal stimulus) into the surface reflectance and illumination components of the scene (the distal stimulus—ground truth). It is agreed that the visual system must compare different regions of the visual image to solve this inverse problem; however, the nature of the comparisons and the mechanisms underlying them are topics of intense debate. Perceptual illusions are of value because they reveal important information about these visual processing mechanisms. We propose a framework for lightness research that resolves confusions and paradoxes in the literature, and provides insight into the mechanisms the visual system employs to tackle the inverse problem. The main idea is that much of the debate and confusion in the literature stems from the fact that lightness, defined as apparent reflectance, is underspecified and refers to three different types of judgments that are not comparable. Under stimulus conditions containing a visible illumination component, such as a shadow boundary, observers can distinguish and match three independent dimensions of achromatic experience: apparent intensity (brightness), apparent local intensity ratio (brightness-contrast), and apparent reflectance (lightness). In the absence of a visible illumination boundary, however, achromatic vision reduces to two dimensions and, depending on stimulus conditions and observer instructions, judgments of lightness are identical to judgments of brightness or brightness-contrast. Furthermore, because lightness judgments are based on different information under different conditions, they can differ greatly in their degree of difficulty and in their accuracy. This may, in part, explain the large variability in lightness constancy across studies. PMID:25954181

  10. Handwriting performance in the absence of visual control in writer's cramp patients: Initial observations

    PubMed Central

    Chakarov, Vihren; Hummel, Sibylla; Losch, Florian; Schulte-Mönting, Jürgen; Kristeva, Rumyana

    2006-01-01

    Background The present study was aimed at investigating the writing parameters of writer's cramp patients and control subjects during handwriting of a test sentence in the absence of visual control. Methods Eight right-handed patients with writer's cramp and eight healthy volunteers as age-matched control subjects participated in the study. The experimental task consisted in writing a test sentence repeatedly for fifty times on a pressure-sensitive digital board. The subject did not have visual control on his handwriting. The writing performance was stored on a PC and analyzed off-line. Results During handwriting all patients developed a typical dystonic limb posture and reported an increase in muscular tension along the experimental session. The patients were significantly slower than the controls, with lower mean vertical pressure of the pen tip on the paper and they could not reach the endmost letter of the sentence in the given time window. No other handwriting parameter differences were found between the two groups. Conclusion Our findings indicate that during writing in the absence of visual feedback writer's cramp patients are slower and could not reach the endmost letter of the test sentence, but their level of automatization is not impaired and writer's cramp handwriting parameters are similar to those of the controls except for even lower vertical pressure of the pen tip on the paper, which is probably due to a changed strategy in such experimental conditions. PMID:16594993

  11. Visual observation and quantitative measurement of the microwave absorbing effect at X band.

    PubMed

    Zhao, L; Chen, X; Ong, C K

    2008-12-01

    We have set up a two-dimensional spatial field mapping system to measure graphically the quasi-free-space electromagnetic wave in a parallel plate waveguide. Our apparatus illustrates a potential application in characterizing the microwave absorbing materials. From the measured mappings of the microwave field, the visualization of spatial physical process and quantitative characterization of reflectivity coefficients can be achieved. This simple apparatus has a remarkable advantage over with conventional testing methods which usually involve huge, expensive anechoic chambers and demand samples of large size. PMID:19123583

  12. Azimuthal instability of the interface in a shear banded flow by direct visual observation.

    PubMed

    Decruppe, J P; Bécu, L; Greffier, O; Fazel, N

    2010-12-17

    The stability of the shear banded flow of a Maxwellian fluid is studied from an experimental point of view using rheology and flow visualization with polarized light. We show that the one-layer homogeneous flow cannot sustain shear rates corresponding to the end of the stress plateau. The high shear rate branch is not found and the shear stress oscillates at the end of the plateau. An azimuthal instability appears: the shear induced band becomes unstable and the interface between the two bands undulates in time and space with a period τ, a wavelength λ and a wave vector k parallel to the direction of the tangential velocity.

  13. Learning from demonstrations: the role of visual search during observational learning from video and point-light models.

    PubMed

    Horn, Robert R; Williams, A Mark; Scott, Mark A

    2002-03-01

    In this study, we examined the visual search strategies used during observation of video and point-light display models. We also assessed the relative effectiveness of video and point-light models in facilitating the learning of task outcomes and movement patterns. Twenty-one female novice soccer players were divided equally into video, point-light display and no-model (control) groups. Participants chipped a soccer ball onto a target area from which radial and variable error scores were taken. Kinematic data were also recorded using an opto-electrical system. Both a pre- and post-test were performed, interspersed with three periods of acquisition and observation of the model. A retention test was completed 2 days after the post-test. There was a significant main effect for test period for outcome accuracy and variability, but observation of a model did not facilitate outcome-based learning. Participants observing the models acquired a global movement pattern that was closer to that of the model than the controls, although they did not acquire the local relations in the movement pattern, evidenced by joint range of motion and angle-angle plots. There were no significant differences in learning between the point-light display and video groups. The point-light display model group used a more selective visual search pattern than the video model group, while both groups became more selective with successive trials and observation periods. The results are discussed in the context of Newell's hierarchy of coordination and control and Scully and Newell's visual perception perspective.

  14. Visual scanning in the recognition of facial affect: is there an observer sex difference?

    PubMed

    Vassallo, Suzane; Cooper, Sian L; Douglas, Jacinta M

    2009-01-01

    This investigation assessed whether differences exist in the way males and females overtly orient their visual attention to salient facial features while viewing static emotional facial expressions. Eye movements were recorded while fifty healthy participants (23 males, 27 females) viewed a series of six universal facial expressions. Groups were compared with respect to accuracy and reaction time in emotional labeling. The number and duration of foveal fixations to four predefined facial areas of interest (AOIs)--each eye, nose, mouth--were also recorded. There were no significant group differences with respect to accuracy (p = 0.997), though females were significantly faster than males in correctly identifying expressions (p = 0.047). Analysis of the visual scan path revealed that while both groups spent more time and looked more frequently at the eye region, males spent significantly more time viewing the nose and mouth. The duration and number of fixations made to the nose were significantly greater in males (p < 0.05). This study is the first to show reaction time differences between the sexes across a range of universal emotions. Further, this is the first work to suggest the orienting of attention to the lower part of the face, especially the nose, appears to differentiate the sexes. PMID:19757950

  15. Ideal and visual-search observers: accounting for anatomical noise in search tasks with planar nuclear imaging

    NASA Astrophysics Data System (ADS)

    Sen, Anando; Gifford, Howard C.

    2015-03-01

    Model observers have frequently been used for hardware optimization of imaging systems. For model observers to reliably mimic human performance it is important to account for the sources of variations in the images. Detection-localization tasks are complicated by anatomical noise present in the images. Several scanning observers have been proposed for such tasks. The most popular of these, the channelized Hotelling observer (CHO) incorporates anatomical variations through covariance matrices. We propose the visual-search (VS) observer as an alternative to the CHO to account for anatomical noise. The VS observer is a two-step process which first identifies suspicious tumor candidates and then performs a detailed analysis on them. The identification of suspicious candidates (search) implicitly accounts for anatomical noise. In this study we present a comparison of these two observers with human observers. The application considered is collimator optimization for planar nuclear imaging. Both observers show similar trends in performance with the VS observer slightly closer to human performance.

  16. In situ observation the interface undercooling of freezing colloidal suspensions with differential visualization method

    NASA Astrophysics Data System (ADS)

    You, Jiaxue; Wang, Lilin; Wang, Zhijun; Li, Junjie; Wang, Jincheng; Lin, Xin; Huang, Weidong

    2015-08-01

    Interface undercooling is one of the most significant parameters in the solidification of colloidal suspensions. However, quantitative measurement of interface undercooling of colloidal suspensions is still a challenge. Here, a new experimental facility and gauging method are designed to directly reveal the interface undercooling on both static and dynamic cases. The interface undercooling is visualized through the discrepancy of solid/liquid interface positions between the suspensions and its solvent in a thermal gradient apparatus. The resolutions of the experimental facility and gauging method are proved to be 0.01 K. The high precision of the method comes from the principle of converting temperature measurement into distance measurement in the thermal gradient platform. Moreover, both static and dynamic interface undercoolings can be quantitatively measured.

  17. Preliminary observations on the ability of hyperspectral imaging to provide detection and visualization of bloodstain patterns on black fabrics.

    PubMed

    Schuler, Rebecca L; Kish, Paul E; Plese, Cara A

    2012-11-01

    The analysis of bloodstain patterns can assist investigators in understanding the circumstances surrounding a violent crime. Bloodstains are routinely subjected to pattern analysis, which is inherently dependent upon the ability of the examiner to locate and visualize bloodstain patterns on items of evidence. Often, the ability to properly visualize bloodstain patterns is challenging, especially when the stain patterns occur on dark and/or patterned substrates. In this study, preliminary research was performed to better understand how near-infrared reflectance hyperspectral imaging (HSI) could be used to observe bloodstain patterns on commonly encountered black fabrics. The ability of HSI to visualize latent bloodstains on several commonly encountered substrates is demonstrated. The images acquired through HSI are of sufficient quality to allow for differentiation between stains produced from an impact mechanism or a transfer mechanism. This study also serves as a proof of concept in the differentiation of multiple staining materials. Because of its ability to generate spectral data, the data provide a preliminary separation of stains where more than one type of stain existed. PMID:22563710

  18. Are There Side Effects to Watching 3D Movies? A Prospective Crossover Observational Study on Visually Induced Motion Sickness

    PubMed Central

    Solimini, Angelo G.

    2013-01-01

    Background The increasing popularity of commercial movies showing three dimensional (3D) images has raised concern about possible adverse side effects on viewers. Methods and Findings A prospective carryover observational study was designed to assess the effect of exposure (3D vs. 2D movie views) on self reported symptoms of visually induced motion sickness. The standardized Simulator Sickness Questionnaire (SSQ) was self administered on a convenience sample of 497 healthy adult volunteers before and after the vision of 2D and 3D movies. Viewers reporting some sickness (SSQ total score>15) were 54.8% of the total sample after the 3D movie compared to 14.1% of total sample after the 2D movie. Symptom intensity was 8.8 times higher than baseline after exposure to 3D movie (compared to the increase of 2 times the baseline after the 2D movie). Multivariate modeling of visually induced motion sickness as response variables pointed out the significant effects of exposure to 3D movie, history of car sickness and headache, after adjusting for gender, age, self reported anxiety level, attention to the movie and show time. Conclusions Seeing 3D movies can increase rating of symptoms of nausea, oculomotor and disorientation, especially in women with susceptible visual-vestibular system. Confirmatory studies which include examination of clinical signs on viewers are needed to pursue a conclusive evidence on the 3D vision effects on spectators. PMID:23418530

  19. The Mirror Neuron System and Observational Learning: Implications for the Effectiveness of Dynamic Visualizations

    ERIC Educational Resources Information Center

    van Gog, Tamara; Paas, Fred; Marcus, Nadine; Ayres, Paul; Sweller, John

    2009-01-01

    Learning by observing and imitating others has long been recognized as constituting a powerful learning strategy for humans. Recent findings from neuroscience research, more specifically on the mirror neuron system, begin to provide insight into the neural bases of learning by observation and imitation. These findings are discussed here, along…

  20. Visual observation of the effect of magnetic field on moving air and vapor bubbles in a magnetic fluid

    NASA Astrophysics Data System (ADS)

    Nakatsuka, K.; Jeyadevan, B.; Akagami, Y.; Torigoe, T.; Asari, S.

    1999-07-01

    Theoretical prediction suggests that magnetic fluid (MF) as working liquid in heat pipe could enhance and control the heat transfer under the application of magnetic field. However, heat pipe experiments using ionic MF showed only marginal gain and demands investigation. As an initial step, visualization of air and vapor bubbles behavior under zero and applied magnetic field has been carried out using X-ray. The observations can be summarized as follows; applied magnetic field (a) reduces the size and deforms the shape of the bubble that secede from the heating surface or air supply tube, and (b) accelerates the movement of the bubble in the liquid.

  1. Cassini Visual and Infrared Mapping Spectrometer observations of Iapetus: Detection of CO2

    USGS Publications Warehouse

    Buratti, B.J.; Cruikshank, D.P.; Brown, R.H.; Clark, R.N.; Bauer, J.M.; Jaumann, R.; McCord, T.B.; Simonelli, D.P.; Hibbitts, C.A.; Hansen, G.B.; Owen, T.C.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Drossart, P.; Formisano, V.; Langevin, Y.; Matson, D.L.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, C.; Roush, T.L.; Soderlund, K.; Muradyan, A.

    2005-01-01

    The Visual and Infrared Mapping Spectrometer (VIMS) instrument aboard the Cassini spacecraft obtained its first spectral map of the satellite lapetus in which new absorption bands are seen in the spectra of both the low-albedo hemisphere and the H2O ice-rich hemisphere. Carbon dioxide is identified in the low-albedo material, probably as a photochemically produced molecule that is trapped in H2O ice or in some mineral or complex organic solid. Other absorption bands are unidentified. The spectrum of the low-albedo hemisphere is satisfactorily modeled with a combination of organic tholin, poly-HCN, and small amounts of H2O ice and Fe 2O3. The high-albedo hemisphere is modeled with H 2O ice slightly darkened with tholin. The detection of CO2 in the low-albedo material on the leading hemisphere supports the contention that it is carbon-bearing material from an external source that has been swept up by the satellite's orbital motion. ?? 2005. The American Astronomical Society. All rights reserved.

  2. Two Position Supine/Prone Myocardial Perfusion SPECT (MPS) Imaging Improves Visual Inter-Observer Correlation and Agreement

    PubMed Central

    Arsanjani, Reza; Hayes, Sean W.; Fish, Mathews; Shalev, Aryeh; Nakanishi, Rine; Thomson, Louise EJ; Friedman, John D; Germano, Guido; Berman, Daniel S.; Slomka, Piotr

    2014-01-01

    Objectives We aimed to compare the inter-observer agreement between two experienced readers using supine versus combined supine/prone myocardial perfusion SPECT (MPS) in a large population. Methods 1181 consecutive patients without known coronary artery disease (CAD) undergoing rest 201Tl/stress 99mTc-sestamibi MPS studies were evaluated. Visual reads were performed in 2 consecutive steps, with readers scoring the stress supine perfusion images during step 1 and rescoring the images using both supine/prone data during step 2. Visual summed stress scores (SSS) of 2 readers including regional scores in different vascular territories were compared. Results The specificity for both readers improved using combined supine/prone imaging (Reader 1: 92% vs. 86% [P=0.0002], Reader 2: 88% vs. 72% [P<0.0001]. The inter-observer correlation for SSS (0.90 vs. 0.84, P<0.0001) and inter-observer agreement for combined supine/prone reading (bias = 1.0, 95% confidence interval (CI) 0.9-1.2 vs. 3.1, 95% CI 2.8-3.4, P<0.0001) were significantly better than for supine-only reading. The overall correlation between SSS scores for two readers improved with supine/prone imaging for both genders, as well as in the left anterior descending and right coronary territories. New Knowledge Gained Combined supine/prone imaging improves overall inter-observer agreement as well as based on gender and vascular territories. Conclusion The inter-observer correlation and agreement significantly improves using two-position supine/prone versus supine-only imaging. PMID:24807622

  3. In-situ visual observation for the formation and dissociation of methane hydrates in porous media by magnetic resonance imaging.

    PubMed

    Zhao, Jiafei; Lv, Qin; Li, Yanghui; Yang, Mingjun; Liu, Weiguo; Yao, Lei; Wang, Shenglong; Zhang, Yi; Song, Yongchen

    2015-05-01

    In this work, magnetic resonance imaging (MRI) was employed to observe the in-situ formation and dissociation of methane hydrates in porous media. Methane hydrate was formed in a high-pressure cell with controlled temperature, and then the hydrate was dissociated by thermal injection. The process was photographed by the MRI, and the pressure was recorded. The images confirmed that the direct visual observation was achieved; these were then employed to provide detailed information of the nucleation, growth, and decomposition of the hydrate. Moreover, the saturation of methane hydrate during the dissociation was obtained from the MRI intensity data. Our results showed that the hydrate saturation initially decreased rapidly, and then slowed down; this finding is in line with predictions based only on pressure. The study clearly showed that MRI is a useful technique to investigate the process of methane hydrate formation and dissociation in porous media.

  4. Why are the Daily Sunspot Observations Interesting? One Observer's Perspective (Abstract)

    NASA Astrophysics Data System (ADS)

    Dempsey, F.

    2016-06-01

    (Abstract only) Daily sunspot counts made for the AAVSO Solar Section may cause the observer to feel in touch with the daily (and longer-term) changes on the sun's surface, and this connection may be more interesting when the solar observer remains aware of the larger solar and geomagnetic environment. The daily sunspot observations may become more interesting when correlated with transient events including solar flares, filaments, coronal holes, and coronal mass ejections that can be followed in near-real time multi-wavelength X-ray and UV solar images as well as particle flux and magnetic field measurements.

  5. The use of intonation for turn anticipation in observed conversations without visual signals as source of information

    PubMed Central

    Keitel, Anne; Daum, Moritz M.

    2015-01-01

    The anticipation of a speaker’s next turn is a key element of successful conversation. This can be achieved using a multitude of cues. In natural conversation, the most important cue for adults to anticipate the end of a turn (and therefore the beginning of the next turn) is the semantic and syntactic content. In addition, prosodic cues, such as intonation, or visual signals that occur before a speaker starts speaking (e.g., opening the mouth) help to identify the beginning and the end of a speaker’s turn. Early in life, prosodic cues seem to be more important than in adulthood. For example, it was previously shown that 3-year-old children anticipated more turns in observed conversations when intonation was available compared with when not, and this beneficial effect was present neither in younger children nor in adults (Keitel et al., 2013). In the present study, we investigated this effect in greater detail. Videos of conversations between puppets with either normal or flattened intonation were presented to children (1-year-olds and 3-year-olds) and adults. The use of puppets allowed the control of visual signals: the verbal signals (speech) started exactly at the same time as the visual signals (mouth opening). With respect to the children, our findings replicate the results of the previous study: 3-year-olds anticipated more turns with normal intonation than with flattened intonation, whereas 1-year-olds did not show this effect. In contrast to our previous findings, the adults showed the same intonation effect as the 3-year-olds. This suggests that adults’ cue use varies depending on the characteristics of a conversation. Our results further support the notion that the cues used to anticipate conversational turns differ in development. PMID:25713548

  6. The use of intonation for turn anticipation in observed conversations without visual signals as source of information.

    PubMed

    Keitel, Anne; Daum, Moritz M

    2015-01-01

    The anticipation of a speaker's next turn is a key element of successful conversation. This can be achieved using a multitude of cues. In natural conversation, the most important cue for adults to anticipate the end of a turn (and therefore the beginning of the next turn) is the semantic and syntactic content. In addition, prosodic cues, such as intonation, or visual signals that occur before a speaker starts speaking (e.g., opening the mouth) help to identify the beginning and the end of a speaker's turn. Early in life, prosodic cues seem to be more important than in adulthood. For example, it was previously shown that 3-year-old children anticipated more turns in observed conversations when intonation was available compared with when not, and this beneficial effect was present neither in younger children nor in adults (Keitel et al., 2013). In the present study, we investigated this effect in greater detail. Videos of conversations between puppets with either normal or flattened intonation were presented to children (1-year-olds and 3-year-olds) and adults. The use of puppets allowed the control of visual signals: the verbal signals (speech) started exactly at the same time as the visual signals (mouth opening). With respect to the children, our findings replicate the results of the previous study: 3-year-olds anticipated more turns with normal intonation than with flattened intonation, whereas 1-year-olds did not show this effect. In contrast to our previous findings, the adults showed the same intonation effect as the 3-year-olds. This suggests that adults' cue use varies depending on the characteristics of a conversation. Our results further support the notion that the cues used to anticipate conversational turns differ in development. PMID:25713548

  7. Visual Observations of the Amorphous-Amorphous Transition in H2O Under Pressure.

    PubMed

    Mishima, O; Takemura, K; Aoki, K

    1991-10-18

    The vapor-deposited low-density amorphous phase of H(2)O was directly compressed at 77 kelvin with a diamond-anvil cell, and the boundary between the low-density amorphous phase and the high-density amorphous phase was observed while the sample was warmed under compression. The transition from the low-density amorphous phase to the high-density amorphous phase was distinct and reversible in an apparently narrow pressure range at approximately 130 to approximately 150 kelvin, which provided experimental evidence for polymorphism in amorphous H(2)O. PMID:17742228

  8. The use of radar and visual observations to characterize the surface structure of the planet Mercury

    NASA Technical Reports Server (NTRS)

    Clark, P. E.; Kobrick, M.; Jurgens, R. F.

    1985-01-01

    An analysis is conducted of available topographic profiles and scattering parameters derived from earth-based S- and X-band radar observations of Mercury, in order to determine the nature and origin of regional surface variations and structures that are typical of the planet. Attention is given to the proposal that intercrater plains on Mercury formed from extensive volcanic flooding during bombardment, so that most craters were formed on a partially molten surface and were thus obliterated, together with previously formed tectonic features.

  9. Changes in visual and sensory-motor resting-state functional connectivity support motor learning by observing.

    PubMed

    McGregor, Heather R; Gribble, Paul L

    2015-07-01

    Motor learning occurs not only through direct first-hand experience but also through observation (Mattar AA, Gribble PL. Neuron 46: 153-160, 2005). When observing the actions of others, we activate many of the same brain regions involved in performing those actions ourselves (Malfait N, Valyear KF, Culham JC, Anton JL, Brown LE, Gribble PL. J Cogn Neurosci 22: 1493-1503, 2010). Links between neural systems for vision and action have been reported in neurophysiological (Strafella AP, Paus T. Neuroreport 11: 2289-2292, 2000; Watkins KE, Strafella AP, Paus T. Neuropsychologia 41: 989-994, 2003), brain imaging (Buccino G, Binkofski F, Fink GR, Fadiga L, Fogassi L, Gallese V, Seitz RJ, Zilles K, Rizzolatti G, Freund HJ. Eur J Neurosci 13: 400-404, 2001; Iacoboni M, Woods RP, Brass M, Bekkering H, Mazziotta JC, Rizzolatti G. Science 286: 2526-2528, 1999), and eye tracking (Flanagan JR, Johansson RS. Nature 424: 769-771, 2003) studies. Here we used a force field learning paradigm coupled with resting-state fMRI to investigate the brain areas involved in motor learning by observing. We examined changes in resting-state functional connectivity (FC) after an observational learning task and found a network consisting of V5/MT, cerebellum, and primary motor and somatosensory cortices in which changes in FC were correlated with the amount of motor learning achieved through observation, as assessed behaviorally after resting-state fMRI scans. The observed FC changes in this network are not due to visual attention to motion or observation of movement errors but rather are specifically linked to motor learning. These results support the idea that brain networks linking action observation and motor control also facilitate motor learning. PMID:25995349

  10. Changes in visual and sensory-motor resting-state functional connectivity support motor learning by observing.

    PubMed

    McGregor, Heather R; Gribble, Paul L

    2015-07-01

    Motor learning occurs not only through direct first-hand experience but also through observation (Mattar AA, Gribble PL. Neuron 46: 153-160, 2005). When observing the actions of others, we activate many of the same brain regions involved in performing those actions ourselves (Malfait N, Valyear KF, Culham JC, Anton JL, Brown LE, Gribble PL. J Cogn Neurosci 22: 1493-1503, 2010). Links between neural systems for vision and action have been reported in neurophysiological (Strafella AP, Paus T. Neuroreport 11: 2289-2292, 2000; Watkins KE, Strafella AP, Paus T. Neuropsychologia 41: 989-994, 2003), brain imaging (Buccino G, Binkofski F, Fink GR, Fadiga L, Fogassi L, Gallese V, Seitz RJ, Zilles K, Rizzolatti G, Freund HJ. Eur J Neurosci 13: 400-404, 2001; Iacoboni M, Woods RP, Brass M, Bekkering H, Mazziotta JC, Rizzolatti G. Science 286: 2526-2528, 1999), and eye tracking (Flanagan JR, Johansson RS. Nature 424: 769-771, 2003) studies. Here we used a force field learning paradigm coupled with resting-state fMRI to investigate the brain areas involved in motor learning by observing. We examined changes in resting-state functional connectivity (FC) after an observational learning task and found a network consisting of V5/MT, cerebellum, and primary motor and somatosensory cortices in which changes in FC were correlated with the amount of motor learning achieved through observation, as assessed behaviorally after resting-state fMRI scans. The observed FC changes in this network are not due to visual attention to motion or observation of movement errors but rather are specifically linked to motor learning. These results support the idea that brain networks linking action observation and motor control also facilitate motor learning.

  11. 3D Visualization of near real-time remote-sensing observation for hurricanes field campaign using Google Earth API

    NASA Astrophysics Data System (ADS)

    Li, P.; Turk, J.; Vu, Q.; Knosp, B.; Hristova-Veleva, S. M.; Lambrigtsen, B.; Poulsen, W. L.; Licata, S.

    2009-12-01

    NASA is planning a new field experiment, the Genesis and Rapid Intensification Processes (GRIP), in the summer of 2010 to better understand how tropical storms form and develop into major hurricanes. The DC-8 aircraft and the Global Hawk Unmanned Airborne System (UAS) will be deployed loaded with instruments for measurements including lightning, temperature, 3D wind, precipitation, liquid and ice water contents, aerosol and cloud profiles. During the field campaign, both the spaceborne and the airborne observations will be collected in real-time and integrated with the hurricane forecast models. This observation-model integration will help the campaign achieve its science goals by allowing team members to effectively plan the mission with current forecasts. To support the GRIP experiment, JPL developed a website for interactive visualization of all related remote-sensing observations in the GRIP’s geographical domain using the new Google Earth API. All the observations are collected in near real-time (NRT) with 2 to 5 hour latency. The observations include a 1KM blended Sea Surface Temperature (SST) map from GHRSST L2P products; 6-hour composite images of GOES IR; stability indices, temperature and vapor profiles from AIRS and AMSU-B; microwave brightness temperature and rain index maps from AMSR-E, SSMI and TRMM-TMI; ocean surface wind vectors, vorticity and divergence of the wind from QuikSCAT; the 3D precipitation structure from TRMM-PR and vertical profiles of cloud and precipitation from CloudSAT. All the NRT observations are collected from the data centers and science facilities at NASA and NOAA, subsetted, re-projected, and composited into hourly or daily data products depending on the frequency of the observation. The data products are then displayed on the 3D Google Earth plug-in at the JPL Tropical Cyclone Information System (TCIS) website. The data products offered by the TCIS in the Google Earth display include image overlays, wind vectors, clickable

  12. Fusion of inertial and visual: a geometrical observer-based approach

    SciTech Connect

    Bonnabel, S.; Rouchon, P.

    2009-03-05

    The problem of combination between inertial sensors and CCD cameras is of paramount importance in various applications in robotics and autonomous navigation. In this paper we develop a totally geometric model for analysis of this problem, independently from a camera model and from the structure of the scene (landmarks etc.). This formulation can be used for data fusion in several inertial navigation problems. The estimation is then decoupled from the structure of the scene. We use it in the particular case of the estimation of the gyroscopes bias and we build a nonlinear observer which is easy to compute, provides an estimation of the biais, filters the image, and is by construction very robust to noise.

  13. A Mid-latitude Cloud Eruption on Titan Observed by the Cassini Visual Infrared Mapping Spectrometer (VIMS) in July 2007

    NASA Astrophysics Data System (ADS)

    Buratti, B. J.; Pitman, K. M.; Baines, K.; Sotin, C.; Brown, R. H.; Clark, R. N.; Nicholson, P. D.; Griffith, C. A.; Le Mouelic, S.; Momary, T.

    2007-12-01

    Mid-latitude clouds on Titan have been monitored by the Cassini spacecraft since they were reported by ground- based observers (Roe et al. 2005, Ap. J. 618, L49). The Cassini Visual Infrared Mapping Spectrometer (VIMS) is especially suited to detecting and mapping these clouds because its wavelength range of 0.4-5.1 microns covers several key methane cloud filters. These clouds may be the result of atmospheric upwelling on Titan (Griffith et al. 2000 Science 290, p. 509; Rannou et al. 2006 Science 311, p. 201), or they may start as plumes coming from active geologic features on Titan (Roe et al. 2005, Science 310, p. 477). Mid-latitude clouds were observed in the early part of the nominal mission (Dec. 2004 and early 2005), but they had disappeared until a large cloud system was observed in summer 2006, in the 0-90 degrees W longitude mid-latitude regions of Titan. A new group of clouds was observed during the two flybys of July 2007, which dwarfs the previous mid-latitude system. These clouds originate in a region centered on ~200 W longitude and ~48 S latitude. Monitoring of mid-latitude clouds will show whether their timescales for formation are compatible with climate models for Titan's atmosphere. If mid-latitude clouds are the result of active geologic processes, there appears to be more than one source on Titan's surface. Work funded by NASA.

  14. Gas and dust in Comet 2P/Encke observed in the visual and submillimeter wavelength ranges

    NASA Astrophysics Data System (ADS)

    Jockers, K.; Szutowicz, S.; Villanueva, G.; Kiselev, N.; Bonev, T.; Hartogh, P.

    2005-06-01

    In November 2003 Comet 2P/Encke was observed simultaneously with the 10-m Heinrich--Hertz Submillimeter Telescope on Mount Graham, Arizona, USA, and the 2-m optical telescope on Mount Rozhen, Bulgaria. Simultaneous radio observations of the 4--3 and 3--2 rotational transitions of HCN and the 0--0 transition of the CN violet band system provide a three-dimensional view on the comet. The observations are consistent with outgassing from the source region I with location and pole position of Comet Encke taken from [14]. The outflow speed is 1.2 km. There is some evidence for another possible parent for CN besides HCN. The visual dust coma of Comet Encke is nearly spherical with a diameter of about 1000 km and a slight extension into Comet Encke's fan. The polarization of the observed NH2 transition at 662 nm is 7% at a phase angle of 94.5°, close to the value for two-atomic molecules. At this phase angle and a wavelength of 642 nm the polarization of Comet Encke's dust is greater than 30%, i.e., exceeds the value for so-called dusty comets.

  15. Visual Earth observation performance in the space environment. Human performance measurement 4: Flight experiments

    NASA Technical Reports Server (NTRS)

    Huth, John F.; Whiteley, James D.; Hawker, John E.

    1993-01-01

    A wide variety of secondary payloads have flown on the Space Transportation System (STS) since its first flight in the 1980's. These experiments have typically addressed specific issues unique to the zero-gravity environment. Additionally, the experiments use the experience and skills of the mission and payload specialist crew members to facilitate data collection and ensure successful completion. This paper presents the results of the Terra Scout experiment, which flew aboard STS-44 in November 1991. This unique Earth Observation experiment specifically required a career imagery analyst to operate the Spaceborne Direct-View Optical System (SpaDVOS), a folded optical path telescope system designed to mount inside the shuttle on the overhead aft flight deck windows. Binoculars and a small telescope were used as backup optics. Using his imagery background, coupled with extensive target and equipment training, the payload specialist was tasked with documenting the following: (1) the utility of the equipment; (2) his ability to acquire and track ground targets; (3) the level of detail he could discern; (4) the atmospheric conditions; and (5) other in-situ elements which contributed to or detracted from his ability to analyze targets. Special emphasis was placed on the utility of a manned platform for research and development of future spaceborne sensors. The results and lessons learned from Terra Scout will be addressed including human performance and equipment design issues.

  16. Drivers' phone use at red traffic lights: a roadside observation study comparing calls and visual-manual interactions.

    PubMed

    Huth, Véronique; Sanchez, Yann; Brusque, Corinne

    2015-01-01

    Phone use while driving has become one of the priority issues in road safety, given that it may lead to decreased situation awareness and deteriorated driving performance. It has been suggested that drivers can regulate their exposure to secondary tasks and seek for compatibility of phone use and driving. Phone use strategies include the choice of driving situations with low demands and interruptions of the interaction when the context changes. Traffic light situations at urban intersections imply both a temptation to use the phone while waiting at the red traffic light and a potential threat due to the incompatibility of phone use and driving when the traffic light turns green. These two situations were targeted in a roadside observation study, with the aim to investigate the existence of a phone use strategy at the red traffic light and to test its effectiveness. N=124 phone users and a corresponding control group of non-users were observed. Strategic phone use behaviour was detected for visual-manual interactions, which are more likely to be initiated at the red traffic light and tend to be stopped before the vehicle moves off, while calls are less likely to be limited to the red traffic light situation. As an indicator of impaired situation awareness, delayed start was associated to phone use and in particular to visual-manual interactions, whether phone use was interrupted before moving off or not. Traffic light situations do not seem to allow effective application of phone use strategies, although drivers attempt to do so for the most demanding phone use mode. The underlying factors of phone use need to be studied so as to reduce the temptation of phone use and facilitate exposure regulation strategies. PMID:25463943

  17. CLOUD AND HAZE IN THE WINTER POLAR REGION OF TITAN OBSERVED WITH VISUAL AND INFRARED MAPPING SPECTROMETER ON BOARD CASSINI

    SciTech Connect

    Rannou, P.; Le Mouelic, S.; Sotin, C.; Brown, R. H.

    2012-03-20

    A large cloud in the north polar region of Titan was first observed by the Visual and Infrared Mapping Spectrometer (VIMS) in 2005 and then in 2006. This cloud, confined beyond the latitude 62 Degree-Sign N, is surrounded by a mixture of aerosol and mist probably lying in the low stratosphere and troposphere. Subsequent images of this region of Titan show a gradual vanishing of this cloud which was reported previously. In this paper, we characterize the physical properties of this cloud, haze, and mist as well as their time evolutions. We note several details on the images such as a secondary cloud above the main cloud and latitudes beyond 70 Degree-Sign N. We also show that the cloud disappearance leaves the polar region poorly loaded in aerosols, yielding an annular zone of aerosols between 50 Degree-Sign N and 65 Degree-Sign N. Our analysis suggests that this structure observed by VIMS in the near-IR is an annular structure observed by ISS on board Voyager one Titan year ago in 1980.

  18. Seeing Chemistry through Sound: A Submersible Audible Light Sensor for Observing Chemical Reactions for Students Who Are Blind or Visually Impaired

    ERIC Educational Resources Information Center

    Supalo, Cary A.; Kreuter, Rodney A.; Musser, Aaron; Han, Josh; Briody, Erika; McArtor, Chip; Gregory, Kyle; Mallouk, Thomas E.

    2006-01-01

    In order to enable students who are blind and visually impaired to observe chemical changes in solutions, a hand-held device was designed to output light intensity as an audible tone. The submersible audible light sensor (SALS) creates an audio signal by which one can observe reactions in a solution in real time, using standard laboratory…

  19. New observations by visualizing age stratification and internal dynamics of freshwater lenses in heterogeneous media - laboratory experiments and numerical simulations

    NASA Astrophysics Data System (ADS)

    Stoeckl, L.; Dose, E.; Houben, G.; Himmelsbach, T.

    2012-12-01

    We performed a series of multi-tracer laboratory scale experiments in a transparent sand-box model to visualize (a) processes during the genesis of freshwater lenses and (b) their internal dynamics. For physical modeling an acrylic glass box was used to simulate a cross section of an island, similar to Stoeckl & Houben (2012). Degassed salt water with a density of 1023 kg/m3 was injected from the bottom, saturating the sand inside the model. Fluorescent tracer dyes uranine, eosine and indigotine were used to mark the infiltrating fresh water from the top. All experiments were filmed and analyzed using fast motion mode. We performed two different types of experimental set-up according to Vacher (1988): (1) Layers of different hydraulic conductivity: By filling the sand-box model with sand of different grain sizes, layers of different hydraulic conductivity could be simulated. (2) Recharge distribution: By recharging the island heterogeneously we could observe shifts in the geometry of the freshwater lens. A novel approach of using different tracer colors and varying them spatially and over time within the recharge waters allowed us to visualize and measure internal flow processes. Age stratification and flow paths could therefore be investigated. Moreover, a combination of temporal and spatial tracer color variation in one single experiment enabled us to measure flow velocities of freshwater movement. Additionally, by injecting small amounts of tracer in the salt water environment, movements near the interface between fresh- and saltwater could be observed. Using the finite element model FEFLOW we could model the density driven dynamics of our small scale freshwater lens, including its formation and the degradation after turning off the recharge water. This is important to fill the gap between our physical sand-box model and ongoing field investigations. The main focus of this work is the effects of climate change as well as geological and morphological

  20. United States Naval Academy Polar Science Program's Visual Arctic Observing Platforms; IceGoat and IceKids

    NASA Astrophysics Data System (ADS)

    Woods, J. E.; Rigor, I. G.; Valentic, T. A.

    2013-12-01

    The U.S. Naval Academy Oceanography Department currently has a curriculum based Polar Science Program (USNA PSP). Within the PSP there is an Arctic Buoy Program (ABP) student research component that will include the design, build, testing and deployment of Arctic Observing Platforms. Establishing an active, field-research program in Polar Science will greatly enhance Midshipman education and research, as well as introduce future Naval Officers to the Arctic environment. The Oceanography Department has engaged the USNA Engineering Departments, and in close collaboration with SRI International, developed the USNA Visual Arctic Observing Platforms. The experience gained through Polar field studies and data derived from these platforms will be used to enhance course materials and laboratories and will also be used directly in Midshipman independent research projects. The USNA PSP successfully deployed IceGoat1 (IG1) off the USCGC HEALY in September, 2012. IG1 suffered a malfunction to its solar powered webcam system upon deployment, but is still reporting via ARGOS SATCOM systems basic weather parameters of air temperature, pressure, and position. USNA PSP attempted to build a less robust, but more economical system integrating similar low power observing platforms housed in heavy duty coolers. This allowed for a streamlined process to get a complete system completed in one academic year. IceKids (IK) are similar observing platforms, just not designed to float once the sea ice melts. IK1 was deployed to Antarctica from October 2012 through January 2013 and captured over 11,000 web cam images in near real time of two remote environmental monitoring stations. IK2A and IK3T were built to be deployed at the Naval Academy Ice Experiment in Barrow, AK in March 2013. IK2A was unique in trying to collect and transmit underwater acoustic signals in near real time. The system integrated a passive hydrophone into the already developed low power data transport system

  1. Observations in the Saturn system during approach and orbital insertion, with Cassini's visual and infrared mapping spectrometer (VIMS)

    USGS Publications Warehouse

    Brown, R.H.; Baines, K.H.; Bellucci, G.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, C.; Baugh, N.; Griffith, C.A.; Hansen, G.B.; Hibbitts, C.A.; Momary, T.W.; Showalter, M.R.

    2006-01-01

    The Visual and Infrared Mapping Spectrometer observed Phoebe, Iapetus, Titan and Saturn's rings during Cassini's approach and orbital insertion. Phoebe's surface contains water ice, CO2, and ferrous iron. lapetus contains CO2 and organic materials. Titan's atmosphere shows methane fluorescence, and night-side atmospheric emission that may be CO2 and CH3D. As determined from cloud motions, the winds at altitude 25-30 km in the south polar region of Titan appear to be moving in a prograde direction at velocity ???1 m s-1. Circular albedo features on Titan's surface, seen at 2.02 ??m, may be palimpsests remaining from the rheological adjustment of ancient impact craters. As such, their long-term persistence is of special interest in view of the expected precipitation of liquids and solids from the atmosphere. Saturn's rings have changed little in their radial structure since the Voyager flybys in the early 1980s. Spectral absorption bands tentatively attributed to Fe2+ suggest that iron-bearing silicates are a source of contamination of the C ring and the Cassini Division. ?? ESO 2006.

  2. Epsilon Aur monitoring during predicted pulsation phase

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.; Templeton, Matthew R.

    2014-09-01

    Dr. Robert Stencel (University of Denver Astronomy Program) has requested that AAVSO observers monitor epsilon Aurigae from now through the end of the observing season. "Studies of the long-term, out-of-eclipse photometry of this enigmatic binary suggest that intervals of coherent pulsation occur at roughly 1/3 of the 27.1-year orbital period. Kloppenborg, et al. noted that stable variation patterns develop at 3,200-day intervals' implying that 'the next span of dates when such events might happen are circa JD ~2457000 (2014 December)'. "These out-of-eclipse light variations often have amplitudes of ~0.1 magnitude in U, and ~0.05 in V, with characteristic timescales of 60-100 days. The AAVSO light curve data to the present may indicate that this coherent phenomenon has begun, but we encourage renewed efforts by observers...to help deduce whether these events are internal to the F star, or externally-driven by tidal interaction with the companion star." Nightly observations or one observation every few days (CCD/PEP/DSLR, VUBR (amplitude too small for visual)) are requested. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. Epsilon Aur was the subject of major international campaigns and the AAVSO's Citizen Sky project as it went through its 27.1-year eclipse in 2009-2011. Over 700 observers worldwide submitted over 20,000 multicolor observations to the AAVSO International Database for this project. Much information on eps Aur is available from the AAVSO, including material on the Citizen Sky website (http://www.aavso.org/epsilon-aurigae and http://www.citizensky.org/content/star-our-project). The Journal of the AAVSO, Volume 40, No. 2 (2012) was devoted to discussion of and research results from this event. See full Alert Notice for more details and observations.

  3. Effects of dynamic luminance modulation on visually induced self-motion perception: observers' perception of illumination is important in perceiving self-motion.

    PubMed

    Nakamura, Shinji; Seno, Takeharu; Ito, Hiroyuki; Sunaga, Shoji

    2013-01-01

    Coherent luminance modulation of visual objects affects visually induced perception of self-motion (vection). The perceptual mechanism underlying the effects of dynamic luminance modulation were investigated with a visual stimulus simulating an external environment illuminated by a moving spotlight (the normal spotlight condition) or an inverted luminance version of it (the inverted luminance condition). Two psychophysical experiments indicated that vection was generally weakened in the inverted luminance condition. The results cannot be fully explained by the undesirable differences of luminosity within the experimental environment, and suggest that the contrast polarity of the visual stimulus has a significant impact on vection. Furthermore, the results show that the dynamic luminance variations weaken vection in the normal spotlight condition in which the observers perceived illumination modulations. In contrast, in the inverted luminance condition, in which the observers cannot perceive the illumination manipulation, the dynamic luminance variations may not impair vection, and may even be expected to strengthen vection, even though they shared similar global and systematic luminance variation with the normal spotlight condition. These experiments suggest that the observer's perception of illumination is a key factor in considering the effects of dynamic luminance modulation of the visual stimulus.

  4. VLA Observations Of T CrB Reveal Increase in Radio Flux Density Between 2014 and 2016

    NASA Astrophysics Data System (ADS)

    Linford, J.; Weston, J.; Chomiuk, L.; Sokoloski, J.; Nelson, T.; Mukai, K.; Finzell, T.; Rupen, M.; Mioduszewski, A.

    2016-06-01

    We report new observations of the symbiotic binary and known recurrent nova T Coronae Borealis (T CrB) with the Karl G. Janksy Very Large Array (VLA). We recently began monitoring T CrB in 2016 May after reports that it was in a super-active state at other wavelengths (Munari, Dallaporta, & Cherini 2016, NewA, 47, 7; ATEL #8675; AAVSO Special Notice 415).

  5. Leslie Peltier, Amateur Astronomer and Observer Extraordinaire

    NASA Astrophysics Data System (ADS)

    Corbin, B. G.

    2003-12-01

    Leslie Copus Peltier, (Jan. 2, 1900-May 10, 1980) was called "the world's greatest non-professional astronomer" by none other than Harlow Shapley, and also referred to as the "the world's greatest living amateur astronomer". He began observing variable stars on March 1, 1918 with an observation of R. Leonis and at the time of his death had made a total of 132,123 observations of variable stars. These were reported to the AAVSO on a consecutive monthly basis stretching from 1918 to his death in 1980. As of October 2003, he was still on AAVSO's list of the top 25 observers in its history. Born on a farm near Delphos, Ohio, his parents were well read and their home was filled with books on different subjects, including nature guides. As a young man he studied the flora and fauna of the area and in 1915 began his study of the heavens with Vega being the first star he identified. After the purchase of a 2-inch spyglass, his observations of variable stars began to be noticed by professional astronomers and the AAVSO loaned him a 4-inch Mogey refractor; shortly thereafter Henry Norris Russell of Princeton loaned him via the AAVSO a 6-inch refractor, a comet seeker of short focus. He discovered 12 comets, 10 of which carry his name, and 6 novae or recurring novae. His design of the "Merry-Go-Round Observatory" was a novel approach with the whole observatory revolving around the observer while seated in his observing chair. Miami University (Ohio) later donated to him their 12-inch Clark refractor with its dome. His first book, Starlight Nights: The Adventures of a Star-Gazer, appeared in 1965. This autobiography, an ode to the joys of observing both the night sky and nature, was written in beautifully descriptive language that helped lead countless readers into astronomy. Departing from astronomy, in 1977 he published The Place on Jennings Creek. Written in the style of the 19th century naturalist, the book was devoted to his family's home, Brookhaven, and its natural

  6. Intensification of the Learning Process: Diagnostic Instruments--Visual Performance Screening Test, Observing the Learner, Questionnaire-Parent. A Series of Reports Designed for Classroom Use.

    ERIC Educational Resources Information Center

    Bucks County Public Schools, Doylestown, PA.

    Instruments for screening visual performance, for observing vision behavior, the learner in general, and the student at a learning task, and a parent questionnaire are described. (See TM 001 363 for a description of the total project; for other related documents, see TM 001 160, 364-368, 370-374.) (MS)

  7. Combination of AUV high resolution mapping and submersible visual observations on the Guaymas Hydrothermal Fields (Southern Trough Ridge)

    NASA Astrophysics Data System (ADS)

    Ondreas, H.; Fouquet, Y.; Normand, A.; Rouxel, O.; Godfroy, A.

    2011-12-01

    The BIG cruise -leg I- was carried out on the Guaymas basin in June 2010 on board the French research vessel L'Atalante. An AUV high-resolution survey was made on the southern trough ridge to gather fine-scale bathymetry and acoustic imagery data. The results of the high resolution survey were used, the next days, to explore the vent's area during several Nautile dives. The southern trough hydrothermal fields of the Guaymas basin have often been studied. However, the local geological context was not really well-defined. During the AUV surveys, maps at 70 m above the seafloor were done over the hydrothermal area. The data were gridded at 2 m spacing. During the same cruise, Nautile dives help us to compare the field observations and the geological features revealed by the high resolution mapping and to investigate the fine-scale relationships between the vents and their geological environment. Integration of these data is made easier by the use of the GIS software technology. It helps us perpetuate data, undertake comparisons, combine different types of data, realize fine-scale geological mapping. Even if some problems are recurrent (precision of positioning, integration of old data...), such combinations of high resolution mapping and visual observations and sampling have changed our vision of hydrothermal geological context. In the Guaymas sedimented spreading axis, our new data show that major hydrothermal sites, in the south part of the southern trough only, are located inside or at the border of 100 to 250 m long, 60 to 150 m wide, 6 to 12 m deep small collapsed sub-circular depressions. The direction of the collapse is variable. Curved faults at the outer border of these depressions control the largest and mature edifices. Smaller, possibly younger, immature chimneys are located at the centre of some depressions. The mature hydrothermal structures appear as mounds up to 80 m in diameter, 20 m in high, each hydrothermal edifice being very-well identified on the

  8. Pulkovo catalog of relative positions and motions of visual double and multiple stars from photographic observations with the 26-inch refractor in 1960-2007

    NASA Astrophysics Data System (ADS)

    Kiselev, A. A.; Kiyaeva, O. V.; Izmailov, I. S.; Romanenko, L. G.; Kalinichenko, O. A.; Vasil'kova, O. O.; Vasil'eva, T. A.; Shakht, N. A.; Gorshanov, D. L.; Roschina, E. A.

    2014-02-01

    The results of long-term, uniform, photographic observations of visual double and multiple stars obtained on the Pulkovo 26″ refractor are presented. Relative positions are calculated for 259 pairs of visual double stars in 194 systems, with the relative motions also computed for 127 pairs. Lower limits for the total masses of the systems for which elliptical orbits possible are also found for 48 pairs with reliable parallaxes from the Hipparcos catalog. The accuracies of the three measuring machines used in the reduction of the photographic plates are compared. Component separations measured with different machines can differ by as much as 0.2″, demonstrating the advantages of using uniform observations.

  9. Observed Human Errors in Interpreting 3D visualizations: implications for Teaching Students how to Comprehend Geological Block Diagrams

    NASA Astrophysics Data System (ADS)

    Bemis, K. G.; Pirl, E.; Chiang, J.; Tremaine, M.

    2009-12-01

    Block diagrams are commonly used to communicate three dimensional geological structures and other phenomena relevant to geological science (e.g., water bodies in the ocean). However, several recent studies have suggested that these 3D visualizations create difficulties for individuals with low to moderate spatial abilities. We have therefore initiated a series of studies to understand what it is about the 3D structures that make them so difficult for some people and also to determine if we can improve people’s understanding of these structures through web-based training not related to geology or other underlying information. Our first study examined what mistakes subjects made in a set of 3D block diagrams designed to represent progressively more difficult internal structures. Each block was shown bisected by a plane either perpendicular or at an angle to the block sides. Five low to medium spatial subjects were asked to draw the features that would appear on the bisecting plane. They were asked to talk aloud as they solved the problem. Each session was videotaped. Using the time it took subjects to solve the problems, the subject verbalizations of their problem solving and the drawings that were found to be in error, we have been able to find common patterns in the difficulties the subjects had with the diagrams. We have used these patterns to generate a set of strategies the subjects used in solving the problems. From these strategies, we are developing methods of teaching. A problem found in earlier work on geology structures was not observed in our study, that is, one of subjects failing to recognize the 2D representation of the block as 3D and drawing the cross-section as a combined version of the visible faces of the object. We attribute this to our experiment introduction, suggesting that even this simple training needs to be carried out with students encountering 3D block diagrams. Other problems subjects had included difficulties in perceptually

  10. How information visualization novices construct visualizations.

    PubMed

    Grammel, Lars; Tory, Melanie; Storey, Margaret-Anne

    2010-01-01

    It remains challenging for information visualization novices to rapidly construct visualizations during exploratory data analysis. We conducted an exploratory laboratory study in which information visualization novices explored fictitious sales data by communicating visualization specifications to a human mediator, who rapidly constructed the visualizations using commercial visualization software. We found that three activities were central to the iterative visualization construction process: data attribute selection, visual template selection, and visual mapping specification. The major barriers faced by the participants were translating questions into data attributes, designing visual mappings, and interpreting the visualizations. Partial specification was common, and the participants used simple heuristics and preferred visualizations they were already familiar with, such as bar, line and pie charts. We derived abstract models from our observations that describe barriers in the data exploration process and uncovered how information visualization novices think about visualization specifications. Our findings support the need for tools that suggest potential visualizations and support iterative refinement, that provide explanations and help with learning, and that are tightly integrated into tool support for the overall visual analytics process.

  11. Wide-field electrographic cameras for imagery and spectrography at visual and middle-UV wavelengths. [for astronomical observations

    NASA Technical Reports Server (NTRS)

    Heckathorn, H. M.; Carruthers, G. R.; Shulman, S. D.

    1979-01-01

    The use of a Kron electrographic detector for wide-field, narrow-band imagery of faint emission nebulosity in the near-UV and visual (3100-6000 A) wavelength interval is described. As an example of the photometric quality of the imagery and of the sensitivity of the instrumentation to diffuse, low-contrast objects, imagery of the Cygnus Loop supernova remnant in the high excitation forbidden line of Ne V 3426 A is presented. In addition, a program to develop electrographic detectors which use cesium telluride photocathodes for broad-band imagery and spectrography in the middle-UV (1650-3100 A) wavelength range is described.

  12. Observing Campaign on Hubble's First Variable in M31: M31_V1

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2010-07-01

    An observing campaign is being carried out on M31_V1, the first variable star discovered in M31 by Edwin Hubble. The Hubble Heritage Team, with Dr. Keith Noll (STScI) as P.I., plans to observe M31_V1 with HST, and needs to know the phase of this Cepheid variable. Although basic parameters are known for this star, no recent photometry exists, so observations are required to generate current phase information. In 1925 Edwin Hubble published a note in The Observatory (vol. 48, 139) on "Cepheids in Spiral Nebulae." In 1929, he published a seminal paper in the Astrophysical Journal (vol. 69, 103), "A Spiral Nebula as a Stellar System, Messier 31." This paper discussed in detail the galaxy and the 50 variable stars he found in its outer regions. Hubble remarked that the 40 Cepheids found showed the period-luminosity relationship in a conspicuous manner, enabling distance to the galaxy to be calculated. Furthermore, he said that the results of his calculations supported the value determined by Harlow Shapley of the zero point of the period-luminosity relation. This confirmation of the zero point had significant implications for future extragalactic distance determinations. As the first of the variables on Hubble's list, V1, a Cepheid, is a historical curiosity. M31_V1 is magnitude 19.4V. B-V = +1.28, period is 30.41 days, and amplitude ~ 1.2 magnitudes in B, likely smaller in V. Five nights of data obtained by Arne Henden, AAVSO, show that the variable appears to have peaked on 2010 June 19 at about R=18 and as of July 2 was on its way down. It is recommended that observers use either an Rc filter or observe unfiltered. About an hour or more of exposure per integration will be required to reach S/N = 20, depending on your equipment and sky brightness; multiple exposures and stacking might be necessary to avoid saturating the background. The field is not crowded, and the variable itself is not blended. Contamination from the M31 background should n! ot be prohibitive

  13. How Students and Field Geologists Reason in Integrating Spatial Observations from Outcrops to Visualize a 3-D Geological Structure

    ERIC Educational Resources Information Center

    Kastens, Kim A.; Agrawal, Shruti; Liben, Lynn S.

    2009-01-01

    Geologists and undergraduate students observed eight artificial "rock outcrops" in a realistically scaled field area, and then tried to envision a geological structure that might plausibly be formed by the layered rocks in the set of outcrops. Students were videotaped as they selected which of fourteen 3-D models they thought best represented the…

  14. Interaction of Jovian White Ovals BC and DE in 1998 from Earth-Based Observations in the Visual Range

    NASA Astrophysics Data System (ADS)

    Sánchez-Lavega, A.; Rojas, J. F.; Hueso, R.; Lecacheux, J.; Colas, F.; Acarreta, J. R.; Miyazaki, I.; Parker, D.

    1999-11-01

    During the 1998 Jupiter-Sun conjunction, the 60-year-old white ovals BC and DE at 33° south latitude merged into a larger oval "BE" at the same latitude (J. Lecacheux, P. Drossart, F. Colas, G. S. Orton, B. Fisher, A. Sanchez-Lavega, R. Hueso, J. F. Rojas, and I. Miyazaki, IAU Circular No. 6942). Here we report our study of the motions, morphology, and reflectivity changes pre and postmerger of the ovals based on extensive and continuous Earth-based CCD imaging (April 1997-September 1998) in the visual range (400-800 nm) and in the methane band at 890 nm. In late August 1997, BC and DE started their mutual approach with a relative zonal velocity of 1 m/s. The longitude drift curves of BC, DE, and new BE suggest that a merger of BC and DE took place in February 1998 in the position of BC. A smaller apparently cyclonic oval called O1 was seen in the northwest side of BE at latitude -31°. BE is about 12% larger than BC or DE as measured in the blue, red, and 890-nm methane band filters. However, if O1 is assumed to be a by-product of the merger, the sum of the areas of BC and DE is about that of BE and O1. The motion of BE is similar to that of the classic white oval spots. No significant center-to-limb reflectivity changes in the white oval spots at the 890-nm wavelength (sensitive to upper hazes and clouds) were noted before and after the merger. However the area-integrated blue-red color index changed slightly, with BE being bluer than BC or DE probably because the particles in BE have a higher single-scattering blue albedo. Using a radiative transfer model, the 890-nm data suggest that the upper cloud and haze (above 600 mbar) in BE are similar to those of BC and DE. In the limit, the upper cloud in BE could be higher (cloudtop at 110 mbar instead of 150 mbar) or have slightly larger optical depths (3.5 instead of 2.85) than that of BC or DE.

  15. Observations of an Eclipse of Bright Star b Persei by the Third Star in February 2013 (Abstract)

    NASA Astrophysics Data System (ADS)

    Collins, D. F.

    2013-12-01

    (Abstract only) b Persei (SAO 24531 = HD 26961, V ~4.52) is a multiple star system consisting of a close ellipsoidal binary with a 1.5-day period and a third star with a 702-day orbit. b Per is a non-thermal radio source, and the evolutionary stage of the close binary is unclear. It may be a non-eclipsing Algol or a precursor to the Algol stage. Observations with the Navy Precision Optical Interferometer showed that the third star has a nearly edge-on orbit about the close binary. Based on this orbit an eclipse of the close binary by the third star was predicted for late January 2013. A call for observations - especially those with equipment to observe bright stars instrumentally - was made via the AAVSO. With the "back yard" convenience of a DSLR camera on a fixed tripod, DFC obtained an observation of the V magnitude of b Persei nearly every clear night in January-February 2013. The DSLR clearly detected the expected eclipse with a drop in of 0.12 V on JD 2456329 and JD 2456330 (Feb 5-6, 2013 and Feb 6-7, 2013). The eclipse was also detected by other AAVSO observers extending to JD 2456331 inclusive. The estimated duration of the eclipse (FWHM) is 2.0 ± 0.3 d. The DSLR also detects the 1.53-day orbital period of the A and B components of b Persei - a variation of 0.05 V magnitude due to the non-eclipsing ellipsoidal star shapes. A concerted campaign should recruit many AAVSO observers to detect the next predicted eclipses in mid-January 2014 (secondary) and early January 2015 (primary) assuming a 702-day cycle. Future photometric observations may aid the understanding of the evolutionary stage of the close binary.

  16. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas.

    PubMed

    Todd, Victoria Louise Georgia; Warley, Jane Clare; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for

  17. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas.

    PubMed

    Todd, Victoria Louise Georgia; Warley, Jane Clare; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for

  18. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas

    PubMed Central

    Todd, Victoria Louise Georgia; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for

  19. Eclipse of epsilon Aurigae

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-07-01

    The bright, long-period, eclipsing binary star epsilon Aurigae is predicted to begin its next eclipse late July or early August of 2009. Epsilon Aurigae is now past solar conjunction and has reappeared as a morning object. All observers -- both visual and instrumental -- are encouraged to contribute observations of the eclipse during the next two years, beginning immediately for morning observers. Observations are urgently requested right now because it is less likely to be observed in the morning, and the eclipse will begin within the next month. The AAVSO is participating in a global campaign to record this eclipse as part of the International Year of Astronomy 2009 celebrations, organized by the Citizen Sky project (http://www.citizensky.org). For experienced visual observers, please observe this star on a weekly basis, using charts available via VSP from the AAVSO website. For novice visual observers, we recommend participating in this observing program by following the Citizen Sky 10-Star tutorial program, which provides a simple training experience in variable star observing. Photoelectric observers belonging to the AAVSO PEP-V program may submit data as usual via the WebObs feature of the AAVSO website Blue&Gold section. Photoelectric observers may also contribute reduced observations in all filters (including infrared J- and H-bands) directly to the AAVSO via WebObs. Observers using wide-field CCD and DSLR systems are also encouraged to participate; avoid saturating the star. For those with narrower-field systems (D < 2 degrees), we recommend taking a large number (10-100) of very short exposures and then stacking the resulting images. Observations should be submitted to the AAVSO International Database. Aaron Price is coordinating Citizen Sky for the AAVSO, and Dr. Robert Stencel and Jeffrey Hopkins are co-leading the precision photometry efforts.

  20. The N170 observed ‘in the wild’: robust event-related potentials to faces in cluttered dynamic visual scenes

    PubMed Central

    Molyneux, Rebecca; Young, Andrew W.

    2015-01-01

    As a social species in a constantly changing environment, humans rely heavily on the informational richness and communicative capacity of the face. Thus, understanding how the brain processes information about faces in real-time is of paramount importance. The N170 is a high-temporal resolution electrophysiological index of the brain’s early response to visual stimuli that is reliably elicited in carefully controlled laboratory-based studies. Although the N170 has often been reported to be of greatest amplitude to faces, there has been debate regarding whether this effect might be an artefact of certain aspects of the controlled experimental stimulation schedules and materials. To investigate whether the N170 can be identified in more realistic conditions with highly variable and cluttered visual images and accompanying auditory stimuli we recorded EEG ‘in the wild’, while participants watched pop videos. Scene-cuts to faces generated a clear N170 response, and this was larger than the N170 to transitions where the videos cut to non-face stimuli. Within participants, wild-type face N170 amplitudes were moderately correlated to those observed in a typical laboratory experiment. Thus, we demonstrate that the face N170 is a robust and ecologically valid phenomenon and not an artefact arising as an unintended consequence of some property of the more typical laboratory paradigm. PMID:25344945

  1. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  2. In-Situ Partial Pressure Measurements and Visual Observation during Crystal Growth of ZnSe by Seeded Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua; Feth, Shari; Lehoczky, Sandor L.

    1999-01-01

    An in-situ monitoring furnace was constructed with side windows to perform partial pressure measurements by optical absorption and visual observation of the growing crystal. A fused silica -rowth ampoule with a 4.5 cm long square tube between the source and the seed was prepared for the optical absorption measurements. A ZnSe crystal was grown by the seeded physical vapor transport (PVT) technique in the horizontal configuration. The growth temperature was 1120 C and the furnace translation rate was 3nmVday. Partial pressures of Se2, P(sub Se2), at three locations along the length of the growth ampoule were measured at 90 min intervals during the growth process. The measured P (sub Se2) were in the range of 2.0 to 6.5 x 10(exp -3) atm. The P(sub Se2) results indicated that the partial pressure profile was inconsistent with the results of the one-dimensional diffusion mass transport model and that the source composition shifted toward Se-rich during the run, i.e. the grown crystal was more Zn-rich than the source. The visual observation showed that the seed crystal first etched back, with greater thermal etching occurring along the edges of the seed crystal. Once the growth started, the crystal crew in a predominately contactless mode and facets were evident during growth. The crystal did not grow symmetrically which is believed to be due to the unintentional asymmetry of the radial thermal profile in the furnace.

  3. Nova Delphini 2013 = PNV J20233073+2046041

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-08-01

    Announces the discovery of Nova Delphini 2013 = PNV J20233073+2046041 = V339 Del by Koichi Itagaki (Teppo-cho, Yamagata, Japan) on 2013 Aug. 14.584 UT at unfiltered CCD magnitude mag 6.8. Spectra by numerous professional and amateur astronomers show strong H-alpha and H-beta emission and P Cygni profile emission lines, all pointing to a pre-maximum classical nova. For details on spectra, see CBET 3628 and the IAU Circular to be announced shortly. Postings to the AAVSO Spectroscopy Forum (http://www.aavso.org/forums/variable-star-observing/spectroscopy) also contain information on spectra, as well as observing and reporting instructions for spectroscopists. Charts for Nova Del 2013 may be created using the AAVSO Variable Star Plotter (VSP) at http://www.aavso.org/vsp. We have created a binocular sequence for this nova that can be plotted using the Binocular Chart option on VSP. Over 750 observations have been submitted to the AAVSO International Database since the nova's discovery two days ago; the most recent observations show Nova Del 2013 has brightened to visual magnitude 4.4. Observations should be submitted to the AAVSO International Database. Announced on IAU CBAT CBET 3628 (Daniel W. E. Green, ed.). Nova Del 2013 was designated PNV J20233073+2046041 when it was posted on the CBAT TOCP webpage. See full Alert Notice for more details, observations, and links to images.

  4. Learning Visualizations by Analogy: Promoting Visual Literacy through Visualization Morphing.

    PubMed

    Ruchikachorn, Puripant; Mueller, Klaus

    2015-09-01

    We propose the concept of teaching (and learning) unfamiliar visualizations by analogy, that is, demonstrating an unfamiliar visualization method by linking it to another more familiar one, where the in-betweens are designed to bridge the gap of these two visualizations and explain the difference in a gradual manner. As opposed to a textual description, our morphing explains an unfamiliar visualization through purely visual means. We demonstrate our idea by ways of four visualization pair examples: data table and parallel coordinates, scatterplot matrix and hyperbox, linear chart and spiral chart, and hierarchical pie chart and treemap. The analogy is commutative i.e. any member of the pair can be the unfamiliar visualization. A series of studies showed that this new paradigm can be an effective teaching tool. The participants could understand the unfamiliar visualization methods in all of the four pairs either fully or at least significantly better after they observed or interacted with the transitions from the familiar counterpart. The four examples suggest how helpful visualization pairings be identified and they will hopefully inspire other visualization morphings and associated transition strategies to be identified.

  5. Time Series Observations of the 2015 Eclipse of b Persei (not beta Persei) (Abstract)

    NASA Astrophysics Data System (ADS)

    Collins, D. F.

    2016-06-01

    (Abstract only) The bright (V = 4.6) ellipsoidal variable b Persei consists of a close non-eclipsing binary pair that shows a nearly sinusoidal light curve with a ~1.5 day period. This system also contains a third star that orbits the binary pair every 702 days. AAVSO observers recently detected the first ever optical eclipse of A-B binary pair by the third star as a series of snapshots (D. Collins, R. Zavala, J. Sanborn - AAVSO Spring Meeting, 2013); abstract published in Collins, JAAVSO, 41, 2, 391 (2013); b Per mis-printed as b Per therein. A follow-up eclipse campaign in mid-January 2015 recorded time-series observations. These new time-series observations clearly show multiple ingress and egress of each component of the binary system by the third star over the eclipse duration of 2 to 3 days. A simulation of the eclipse was created. Orbital and some astrophysical parameters were adjusted within constraints to give a reasonable fit to the observed light curve.

  6. A method to analyse observer disagreement in visual grading studies: example of assessed image quality in paediatric cerebral multidetector CT images.

    PubMed

    Ledenius, K; Svensson, E; Stålhammar, F; Wiklund, L-M; Thilander-Klang, A

    2010-07-01

    The purpose was to demonstrate a non-parametric statistical method that can identify and explain the components of observer disagreement in terms of systematic disagreement as well as additional individual variability, in visual grading studies. As an example, the method was applied to a study where the effect of reduced tube current on diagnostic image quality in paediatric cerebral multidetector CT (MDCT) images was investigated. Quantum noise, representing dose reductions equivalent to steps of 20 mA, was artificially added to the raw data of 25 retrospectively selected paediatric cerebral MDCT examinations. Three radiologists, blindly and randomly, assessed the resulting images from two different levels of the brain with regard to the reproduction of high- and low-contrast structures and overall image quality. Images from three patients were assessed twice for the analysis of intra-observer disagreement. The intra-observer disagreement in test-retest assessments could mainly be explained by a systematic change towards lower image quality the second time the image was reviewed. The inter-observer comparisons showed that the paediatric radiologist was more critical of the overall image quality, while the neuroradiologists were more critical of the reproduction of the basal ganglia. Differences between the radiologists regarding the extent to which they used the whole classification scale were also found. The statistical method used was able to identify and separately measure a presence of bias apart from additional individual variability within and between the radiologists which is, at the time of writing, not attainable by any other statistical approach suitable for paired, ordinal data.

  7. VERITAS Blazar Observations - Recent Results

    SciTech Connect

    Cogan, Peter

    2008-12-24

    We present the discovery of very high energy (VHE) gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 0806+524 (z = 0.138) and the intermediate-frequency-peaked BL Lac object W Comae (z = 0.102) with VERITAS. VHE emission was discovered from these objects during the 2007/2008 observing campaign, with a strong outburst from W Comae detected in mid-March, lasting a few days. Quasi-simultaneous spectral energy distributions are presented, incorporating optical (AAVSO), and X-ray (Swift/RXTE) observations. We also present the energy spectrum of the distant BL Lac (z = 0.182) 1ES 1218+304 which was detected by VERITAS during the 2006/2007 observing campaign. The energy spectrum is discussed in the context of different models of absorption from the diffuse extragalactic background radiation. We present multiwavelength observations of the blazar Markarian 421 (z = 0.03), including a strong flare initially detected by the Whipple 10 m gamma-ray telescope. Finally we present a broadband spectral energy distribution for 1ES 2344+514 (z = 0.044) which is successfully fit using a one zone synchrotron self-Compton model.

  8. Advancing Variable Star Astronomy: The Centennial History of the American Association of Variable Star Observers

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.; Saladyga, Michael

    2011-05-01

    Preface; Part I. Pioneers in Variable Star Astronomy Prior to 1909: 1. The emergence of variable star astronomy - a need for observations; 2. A need for observers; Part II. The Founding of the AAVSO - The William Tyler Olcott Era: 3. The amateur's amateur; 4. Amateurs in the service of science; Part III. The Leon Campbell Era: 5. Leon Campbell to the rescue; 6. Formalizing relationships; 7. The Pickering Memorial Endowment; 8. Fading of the Old Guard; 9. Growing pains and distractions; Part IV. The Service Bureau - The Margaret Mayall Era: 10. Learning about independence; 11. Eviction from Harvard College Observatory; 12. Actions and reactions; 13. In search of a home; 14. Survival on Brattle Street; 15. AAVSO achievements; 16. Breathing room on Concord Avenue; Part V. Analysis and Science: The Janet Mattei Era: 17. The growth of a director; 18. Learning the ropes the hard way; 19. Managing with renewed confidence; 20. Expanding the scientific charter; Part VI. Accelerating Observational Science - The Arne Henden Era: 21. Bridging the gap; 22. Accelerating the science - the Henden era begins; Epilogue; Appendices; Index.

  9. Improving Geologic Mapping of Mid-ocean Ridges by Integrating sonar and Visual Observations through Seafloor Classification by Machine-learning Systems

    NASA Astrophysics Data System (ADS)

    White, S. M.; McClinton, J. T.

    2011-12-01

    Beyond the ability of modern near-bottom sonar systems to deliver air-photo-like images of the seafloor to help guide fieldwork, there is a tremendous amount of information hidden within sonar data that is rarely exploited for geologic mapping. Seafloor texture, backscatter amplitude, seafloor slope and roughness data can provide clues about seafloor geology but not straightforward to interpret. We present techniques for seafloor classification in volcanic terrains that integrate the capability of high-resolution, near-bottom sonar instruments to cover extensive areas of seafloor with the ability of visual mapping to discriminate differences in volcanic terrain. These techniques are adapted from the standard practices of terrestrial remote-sensing for use in the deep seafloor volcanic environment. A combination of sonar backscatter and bathymetry is used to supplement the direct seafloor visual observations by geologists to make quasi-geologic thematic maps that are consistent, objective, and most importantly spatially complete. We have taken two approaches to producing thematic maps of the seafloor for the accurate mapping of fine-scale lava morphology (e.g. pillow, lobate and sheet lava) and for the differentiation of distinct seafloor terrain types on a larger scale (e.g. hummocky or smooth). Mapping lava morphology is most accurate using fuzzy logic capable of making inferences between similar morphotypes (e.g. pillow and lobate) and where high-resolution side-scan and bathymetry data coexist. We present examples of lava morphology maps from the Galápagos Spreading Center that show the results from several analyses using different types of input data. Lava morphology is an important source of information on volcanic emplacement and eruptive dynamics. Terrain modeling can be accomplished at any resolution level, depending on the desired use of the model. For volcanic processes, input data needs to be at the appropriate scale to resolve individual volcanic

  10. Progress in Scientific Visualization

    SciTech Connect

    Max, N

    2004-11-15

    Visualization of observed data or simulation output is important to science and engineering. I have been particularly interested in visualizing 3-D structures, and report here my personal impressions on progress in the last 20 years in visualizing molecules, scalar fields, and vector fields and their associated flows. I have tried to keep the survey and list of references manageable, so apologize to those authors whose techniques I have not mentioned, or have described without a reference citation.

  11. Visual agnosia.

    PubMed

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes.

  12. Halftone visual cryptography.

    PubMed

    Zhou, Zhi; Arce, Gonzalo R; Di Crescenzo, Giovanni

    2006-08-01

    Visual cryptography encodes a secret binary image (SI) into n shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the n shares, however, have no visual meaning and hinder the objectives of visual cryptography. Extended visual cryptography [1] was proposed recently to construct meaningful binary images as shares using hypergraph colourings, but the visual quality is poor. In this paper, a novel technique named halftone visual cryptography is proposed to achieve visual cryptography via halftoning. Based on the blue-noise dithering principles, the proposed method utilizes the void and cluster algorithm [2] to encode a secret binary image into n halftone shares (images) carrying significant visual information. The simulation shows that the visual quality of the obtained halftone shares are observably better than that attained by any available visual cryptography method known to date.

  13. [Progressive visual agnosia].

    PubMed

    Sugimoto, Azusa; Futamura, Akinori; Kawamura, Mitsuru

    2011-10-01

    Progressive visual agnosia was discovered in the 20th century following the discovery of classical non-progressive visual agnosia. In contrast to the classical type, which is caused by cerebral vascular disease or traumatic injury, progressive visual agnosia is a symptom of neurological degeneration. The condition of progressive visual loss, including visual agnosia, and posterior cerebral atrophy was named posterior cortical atrophy (PCA) by Benson et al. (1988). Progressive visual agnosia is also observed in semantic dementia (SD) and other degenerative diseases, but there is a difference in the subtype of visual agnosia associated with these diseases. Lissauer (1890) classified visual agnosia into apperceptive and associative types, and it in most cases, PCA is associated with the apperceptive type. However, SD patients exhibit symptoms of associative visual agnosia before changing to those of semantic memory disorder. Insights into progressive visual agnosia have helped us understand the visual system and discover how we "perceive" the outer world neuronally, with regard to consciousness. Although PCA is a type of atypical dementia, its diagnosis is important to enable patients to live better lives with appropriate functional support.

  14. Bayesian evaluation of clinical diagnostic test characteristics of visual observations and remote monitoring to diagnose bovine respiratory disease in beef calves.

    PubMed

    White, Brad J; Goehl, Dan R; Amrine, David E; Booker, Calvin; Wildman, Brian; Perrett, Tye

    2016-04-01

    Accurate diagnosis of bovine respiratory disease (BRD) in beef cattle is a critical facet of therapeutic programs through promotion of prompt treatment of diseased calves in concert with judicious use of antimicrobials. Despite the known inaccuracies, visual observation (VO) of clinical signs is the conventional diagnostic modality for BRD diagnosis. Objective methods of remotely monitoring cattle wellness could improve diagnostic accuracy; however, little information exists describing the accuracy of this method compared to traditional techniques. The objective of this research is to employ Bayesian methodology to elicit diagnostic characteristics of conventional VO compared to remote early disease identification (REDI) to diagnose BRD. Data from previous literature on the accuracy of VO were combined with trial data consisting of direct comparison between VO and REDI for BRD in two populations. No true gold standard diagnostic test exists for BRD; therefore, estimates of diagnostic characteristics of each test were generated using Bayesian latent class analysis. Results indicate a 90.0% probability that the sensitivity of REDI (median 81.3%; 95% probability interval [PI]: 55.5, 95.8) was higher than VO sensitivity (64.5%; PI: 57.9, 70.8). The specificity of REDI (median 92.9%; PI: 88.2, 96.9) was also higher compared to VO (median 69.1%; PI: 66.3, 71.8). The differences in sensitivity and specificity resulted in REDI exhibiting higher positive and negative predictive values in both high (41.3%) and low (2.6%) prevalence situations. This research illustrates the potential of remote cattle monitoring to augment conventional methods of BRD diagnosis resulting in more accurate identification of diseased cattle. PMID:26879058

  15. Visual sensitivity tester

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A.

    1972-01-01

    Testing device uses closed loop film cassettes to project programmed visual stimuli on screen which the observer views through a lens making the stimuli appear to be at optical infinity. Tester is useful for determining changes in glautomatous visual field sensitivity.

  16. Lessons Learned During the Recent ɛ Aurigae Eclipse Observing Campaign

    NASA Astrophysics Data System (ADS)

    Stencel, R. E.

    2012-06-01

    (Abstract only) The eighteen-month-long eclipse of the third-magnitude star, epsilon Aurigae, is forecast to end during May 2011, based on six eclipse events, in 2010, 1982, 1955, 1930, 1902, and 1874. In partnership with AAVSO, Hopkins Phoenix Observatory, and others, we have organized observing campaigns during the past several years in order to maximize data acquired during this rare event and to promote reporting and analysis of observations of all kinds. Hundreds of registered participants have signed up for alert notices and newsletters, and many dozens of observers have contributed photometry, spectra, and ideas to the ongoing effort - see websites: www.CitizenSky.org and www.hposoft.com/Campaign09.html. In this presentation, I will provide an update on the participation leading to extensive photometric results. Similarly, bright star spectroscopy has greatly benefited from small telescope plus spectrometer capabilities, now widely available, that complement traditional but less-frequent large telescope high dispersion work. Polarimetry provided key insights during the last eclipse, and we promoted the need for new data using this method. Finally, interferometry has come of age since the last eclipse, leading to the direct detection of the transiting dark disk causing the eclipse. Along with these traditional measurements, I will outline campaign-related efforts to promote Citizen Science opportunities among the public. Support for these efforts derives in part from AAVSO/NSF-Informal Science Education, NSF AAG grant 10-16678, and a bequest to the University of Denver Astronomy Program by alumnus William Herschel Womble, for which I am grateful.

  17. Temporal variability of total cloud cover at a Mediterranean megacity in the 20th century: Evidence from visual observations and climate models

    NASA Astrophysics Data System (ADS)

    Founda, Dimitra; Giannakopoulos, Christos; Pierros, Fragiskos

    2013-04-01

    Cloud cover is one of the major factors that determine the radiation budget and the climate system of the Earth. Moreover, the response of clouds has always been an important source of uncertainty in global climate models. Visual surface observations of clouds have been conducted at the National Observatory of Athens (NOA) since the mid 19th century. The historical archive of cloud reports at NOA since 1860 has been digitized and updated, spanning now a period of one and a half century. Mean monthly values of total cloud cover were derived by averaging subdaily observations of cloud cover (3 observations/day). Changes in observational practice (e.g. from 1/10 to 1/8 units) were considered, however, subjective measures of cloud cover from trained observers introduces some kind of uncertainty in the time series. Data before 1884 were considered unreliable, so the analysis was restricted to the series from 1884 to 2012. The time series of total cloud cover at NOA is validated and correlated with historical time series of other (physically related) variables such as the total sunshine duration as well as DTR (Diurnal Temperature Range) which are independently measured. Trend analysis was performed on the mean annual and seasonal series of total cloud cover from 1884-2012. The mean annual values show a marked temporal variability with sub periods of decreasing and increasing tendencies, however, the overall linear trend is positive and statistically significant (p <0.001) amounting to +2% per decade and implying a total increase of almost 25% for the whole analysed period. These results are in agreement qualitatively with the trends reported in other studies worldwide, especially concerning the period before the mid 20th century. On a seasonal basis, spring and summer series present outstanding positive long term trends, while in winter and autumn total cloud cover reveals also positive but less pronounced long term trends Additionally, an evaluation of cloud cover and

  18. Support for Spitzer observations of tremendous outburst amplitude dwarf novae (TOADs)

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2008-05-01

    Dr. Steve Howell (NOAO) requests monitoring of a subset of the known and suspected tremendous outburst amplitude dwarf novae (TOADs) in support of Spitzer Space Telescope observations of these objects. The campaign will run from May 16, 2008, through May 2009. Once an object has been verified in superoutburst, Spitzer observations will be scheduled within 2-4 weeks of maximum, and will be repeated twice -- 4-6 weeks and 6-10 weeks later. Observers are asked to provide nightly monitoring of these stars, and to begin intensive observations if and when any of them go into outburst to determine whether the star is in superoutburst. We note that several of these objects -- notably the WZ Sge stars WZ Sge, GW Lib, and V455 And -- are not expected to superoutburst during the next year, but observations are still encouraged in case they exhibit unexpected behavior. Observations should be submitted to the AAVSO International Database.

  19. NASA/NOAA Earth Science Electronic Theater 1999. Earth Science Observations, Analysis and Visualization: Roots in the 60s: Vision for the Next Millennium

    NASA Technical Reports Server (NTRS)

    Hasler, Fritz

    1999-01-01

    The Etheater presents visualizations which span the period from the original Suomi/Hasler animations of the first ATS-1 GEO weather satellite images in 1966 ....... to the latest 1999 NASA Earth Science Vision for the next 25 years. Hot off the SGI-Onyx Graphics-Supercomputer are NASA's visualizations of Hurricanes Mitch, Georges, Fran and Linda. These storms have been recently featured on the covers of National Geographic, Time, Newsweek and Popular Science. Highlights will be shown from the NASA hurricane visualization resource video tape in standard and HDTV that has been used repeatedly this season on National and International network TV. Results will be presented from a new paper on automatic wind measurements in Hurricane Luis from 1-min GOES images that appeared in the November BAMS.

  20. NASA/NOAA: Earth Science Electronic Theater 1999. Earth Science Observations, Analysis and Visualization: Roots in the 60s - Vision for the Next Millennium

    NASA Technical Reports Server (NTRS)

    Hasler, A. Fritz

    1999-01-01

    The Etheater presents visualizations which span the period from the original Suomi/Hasler animations of the first ATS-1 GEO weather satellite images in 1966, to the latest 1999 NASA Earth Science Vision for the next 25 years. Hot off the SGI-Onyx Graphics-Supercomputer are NASA''s visualizations of Hurricanes Mitch, Georges, Fran and Linda. These storms have been recently featured on the covers of National Geographic, Time, Newsweek and Popular Science. Highlights will be shown from the NASA hurricane visualization resource video tape that has been used repeatedly this season on National and International network TV. Results will be presented from a new paper on automatic wind measurements in Hurricane Luis from 1-min GOES images that appeared in the November BAMS. The visualizations are produced by the NASA Goddard Visualization & Analysis Laboratory, and Scientific Visualization Studio, as well as other Goddard and NASA groups using NASA, NOAA, ESA, and NASDA Earth science datasets. Visualizations will be shown from the Earth Science ETheater 1999 recently presented in Tokyo, Paris, Munich, Sydney, Melbourne, Honolulu, Washington, New York, and Dallas. The presentation Jan 11-14 at the AMS meeting in Dallas used a 4-CPU SGI/CRAY Onyx Infinite Reality Super Graphics Workstation with 8 GB RAM and a Terabyte Disk at 3840 X 1024 resolution with triple synchronized BarcoReality 9200 projectors on a 60ft wide screen. Visualizations will also be featured from the new Earth Today Exhibit which was opened by Vice President Gore on July 2, 1998 at the Smithsonian Air & Space Museum in Washington, as well as those presented for possible use at the American Museum of Natural History (NYC), Disney EPCOT, and other venues. New methods are demonstrated for visualizing, interpreting, comparing, organizing and analyzing immense HyperImage remote sensing datasets and three dimensional numerical model results. We call the data from many new Earth sensing satellites, Hyper

  1. Visual Scripting.

    ERIC Educational Resources Information Center

    Halas, John

    Visual scripting is the coordination of words with pictures in sequence. This book presents the methods and viewpoints on visual scripting of fourteen film makers, from nine countries, who are involved in animated cinema; it contains concise examples of how a storybook and preproduction script can be prepared in visual terms; and it includes a…

  2. Modern Observations of Hubble's First-discovered Cepheid in M31

    NASA Astrophysics Data System (ADS)

    Templeton, M.; Henden, A.; Goff, W.; Smith, S.; Sabo, R.; Walker, G.; Buchheim, R.; Belcheva, G.; Crawford, T.; Cook, M.; Dvorak, S.; Harris, B.

    2011-12-01

    We present a modern ephemeris and modern light curve of the first-discovered Cepheid variable in M31, Edwin Hubble's M31-V1. Observers of the American Association of Variable Star Observers (AAVSO) undertook these observations during the latter half of 2010. The observations were in support of an outreach program by the Space Telescope Science Institute's Hubble Heritage project, but the resulting data are the first concentrated observations of M31-V1 made in modern times. AAVSO observers obtained 214 V-band, Rc-band, and unfiltered observations from which a current ephemeris was derived. The ephemeris derived from these observations is JDMax = 2,455,430.5( ± 0.5) + 31.4( ± 0.1)E. The period derived from the 2010 data is in agreement with the historic values of the period, but the single season of data precludes a more precise determination of the period or measurement of the period change using these data alone. However, using an ephemeris based upon the period derived by Baade and Swope, we are able to fit all of the observed data acceptably well. Continued observations in the modern era will be very valuable in linking these modern data with data from the 1920s-1930s and 1950s and will enable us to measure period change in this historic Cepheid. In particular, we strongly encourage intensive observations of this star around predicted times of maximum to constrain the date of maximum to better than 0.5 days.

  3. Visual Imagery without Visual Perception?

    ERIC Educational Resources Information Center

    Bertolo, Helder

    2005-01-01

    The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review…

  4. Visual Literacy and Visual Culture.

    ERIC Educational Resources Information Center

    Messaris, Paul

    Familiarity with specific images or sets of images plays a role in a culture's visual heritage. Two questions can be asked about this type of visual literacy: Is this a type of knowledge that is worth building into the formal educational curriculum of our schools? What are the educational implications of visual literacy? There is a three-part…

  5. Observing Campaign to Monitor Magnetically-Active Dwarfs for Long-Term Variability

    NASA Astrophysics Data System (ADS)

    Templeton, Matthew R.

    2009-10-01

    Dr. Styliani (Stella) Kafka of the Department of Terrestrial Magnetism, Carnegie Institute of Washington, requests AAVSO observers to perform long-term photometric monitoring on a number of magnetically active dwarf stars, with an observing frequency of one observation every three days taken with one or more filters. When multiple filters are available, the preferred observations are (in order of precedence): Rc, V, Ic, and B. Please observe such that you obtain a signal to noise of at least 50 (100 or higher is preferred). These objects are all nearby dwarfs known or suspected to have magnetic activity, primarily of the UV Ceti (flare star) or BY Draconis subtypes. Long-term photometric monitoring of these objects will be used in conjunction with other multiwavelength observations from ground-based facilities including the Magellan 6.5-meter and DuPont 2.5-meter telescopes in Chile to understand the long-term magnetic activity cycles of these stars. Such a study can reveal information about the physical natures of these stars, but also about their near space environments and habitability for life. These objects are red, and the variability amplitudes are low, often well below 0.1 magnitudes. The long-term variability due to stellar activity cycles may be much lower. Photometric accuracy rather than the number of observations are key to the success of this project. Unaccounted-for atmospheric effects such as extinction will likely overwhelm any long-term signal from these stars. Observers are strongly urged to fully calibrate their systems and to carefully reduce and transform their photometry to standard photometric passbands, including corrections for airmass/atmospheric extinction. Parameters for 40 objects are given. Observations should be submitted to the AAVSO International Database.

  6. Roles of Treg/Th17 Cell Imbalance and Neuronal Damage in the Visual Dysfunction Observed in Experimental Autoimmune Optic Neuritis Chronologically.

    PubMed

    Liu, Yuanyuan; You, Caiyun; Zhang, Zhuhong; Zhang, Jingkai; Yan, Hua

    2015-12-01

    Optic neuritis associated with multiple sclerosis and its animal model, experimental autoimmune optic neuritis (EAON), is characterized by inflammation, T cell activation, demyelination, and neuronal damage, which might induce permanent vision loss. Elucidating the chronological relationship among the features is critical for treatment of demyelinating optic neuritis. EAON was induced in C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein subcutaneously, and visual function was assessed by flash-visual evoked potential (F-VEP) at days 7, 11, 14, 19, 23, 28 post-immunization. Retinal ganglion cell (RGC) apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick-end labeling. Demyelination and axonal damage were verified with myelin basic protein (MBP) and β-amyloid precursor protein staining, respectively. Real-time polymerase chain reaction quantified IL-17, IL-1β, TGF-β, FoxP3, IL-6, and IL-10 mRNA expression in the optic nerve, as well as FoxP3 and IL-17 staining. Systemic changes of Th17 and Treg cells were tested by flow cytometry in spleen. F-VEP latency was prolonged at 11 days and peaked at 23 days commensurate with demyelination. However, F-VEP amplitude was reduced at 11 days, preceding axon damage, and was exacerbated at 23 days when a peak in RGC apoptosis was detected. Th17 cells up-regulated as early as 7 days and peaked at 11 days, while Treg cells down-regulated inversely compared to Th17 cells change as verified by IL-17 and FoxP3 expression; spleen cell samples were slightly different, demonstrating marked changed at 14 days. Treg/Th17 cell imbalance in the optic nerve precedes and may initiate neuronal damage of axons and RGCs. These changes are commensurate with the appearances of visual dysfunction reflected in F-VEP and hence may offer a novel therapeutic avenue for vision preservation. PMID:26318182

  7. Roles of Treg/Th17 Cell Imbalance and Neuronal Damage in the Visual Dysfunction Observed in Experimental Autoimmune Optic Neuritis Chronologically.

    PubMed

    Liu, Yuanyuan; You, Caiyun; Zhang, Zhuhong; Zhang, Jingkai; Yan, Hua

    2015-12-01

    Optic neuritis associated with multiple sclerosis and its animal model, experimental autoimmune optic neuritis (EAON), is characterized by inflammation, T cell activation, demyelination, and neuronal damage, which might induce permanent vision loss. Elucidating the chronological relationship among the features is critical for treatment of demyelinating optic neuritis. EAON was induced in C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein subcutaneously, and visual function was assessed by flash-visual evoked potential (F-VEP) at days 7, 11, 14, 19, 23, 28 post-immunization. Retinal ganglion cell (RGC) apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick-end labeling. Demyelination and axonal damage were verified with myelin basic protein (MBP) and β-amyloid precursor protein staining, respectively. Real-time polymerase chain reaction quantified IL-17, IL-1β, TGF-β, FoxP3, IL-6, and IL-10 mRNA expression in the optic nerve, as well as FoxP3 and IL-17 staining. Systemic changes of Th17 and Treg cells were tested by flow cytometry in spleen. F-VEP latency was prolonged at 11 days and peaked at 23 days commensurate with demyelination. However, F-VEP amplitude was reduced at 11 days, preceding axon damage, and was exacerbated at 23 days when a peak in RGC apoptosis was detected. Th17 cells up-regulated as early as 7 days and peaked at 11 days, while Treg cells down-regulated inversely compared to Th17 cells change as verified by IL-17 and FoxP3 expression; spleen cell samples were slightly different, demonstrating marked changed at 14 days. Treg/Th17 cell imbalance in the optic nerve precedes and may initiate neuronal damage of axons and RGCs. These changes are commensurate with the appearances of visual dysfunction reflected in F-VEP and hence may offer a novel therapeutic avenue for vision preservation.

  8. Helicopter Visual Aid System

    NASA Technical Reports Server (NTRS)

    Baisley, R. L.

    1973-01-01

    The results of an evaluation of police helicopter effectiveness revealed a need for improved visual capability. A JPL program developed a method that would enhance visual observation capability for both day and night usage and demonstrated the feasibility of the adopted approach. This approach made use of remote pointable optics, a display screen, a slaved covert searchlight, and a coupled camera. The approach was proved feasible through field testing and by judgement against evaluation criteria.

  9. Visual adaptation dominates bimodal visual-motor action adaptation

    PubMed Central

    de la Rosa, Stephan; Ferstl, Ylva; Bülthoff, Heinrich H.

    2016-01-01

    A long standing debate revolves around the question whether visual action recognition primarily relies on visual or motor action information. Previous studies mainly examined the contribution of either visual or motor information to action recognition. Yet, the interaction of visual and motor action information is particularly important for understanding action recognition in social interactions, where humans often observe and execute actions at the same time. Here, we behaviourally examined the interaction of visual and motor action recognition processes when participants simultaneously observe and execute actions. We took advantage of behavioural action adaptation effects to investigate behavioural correlates of neural action recognition mechanisms. In line with previous results, we find that prolonged visual exposure (visual adaptation) and prolonged execution of the same action with closed eyes (non-visual motor adaptation) influence action recognition. However, when participants simultaneously adapted visually and motorically – akin to simultaneous execution and observation of actions in social interactions - adaptation effects were only modulated by visual but not motor adaptation. Action recognition, therefore, relies primarily on vision-based action recognition mechanisms in situations that require simultaneous action observation and execution, such as social interactions. The results suggest caution when associating social behaviour in social interactions with motor based information. PMID:27029781

  10. Visual Theorems.

    ERIC Educational Resources Information Center

    Davis, Philip J.

    1993-01-01

    Argues for a mathematics education that interprets the word "theorem" in a sense that is wide enough to include the visual aspects of mathematical intuition and reasoning. Defines the term "visual theorems" and illustrates the concept using the Marigold of Theodorus. (Author/MDH)

  11. Mathematical Visualization

    ERIC Educational Resources Information Center

    Rogness, Jonathan

    2011-01-01

    Advances in computer graphics have provided mathematicians with the ability to create stunning visualizations, both to gain insight and to help demonstrate the beauty of mathematics to others. As educators these tools can be particularly important as we search for ways to work with students raised with constant visual stimulation, from video games…

  12. Visual Closure.

    ERIC Educational Resources Information Center

    Groffman, Sidney

    An experimental test of visual closure based on an information-theory concept of perception was devised to test the ability to discriminate visual stimuli with reduced cues. The test is to be administered in a timed individual situation in which the subject is presented with sets of incomplete drawings of simple objects that he is required to name…

  13. Visual Thinking.

    ERIC Educational Resources Information Center

    Arnheim, Rudolf

    Based on the more general principle that all thinking (including reasoning) is basically perceptual in nature, the author proposes that visual perception is not a passive recording of stimulus material but an active concern of the mind. He delineates the task of visually distinguishing changes in size, shape, and position and points out the…

  14. Visual observation of the dynamic flow of elastomer rubber impression material between the impression tray and oral mucosa while seating the impression tray.

    PubMed

    Nishigawa, G; Natsuaki, N; Maruo, Y; Okamoto, M; Minagi, S

    2003-06-01

    The purpose of this study was to inspect visually, the dynamics of the impression flow at seating of the impression tray. The effects of the relief and the escape hole of the impression tray on the impression flow were also examined. Three types of the transparent impression tray (flat tray, relief tray and escape hole tray) were prepared. Transparent silicone polymer was put on the impression tray surface. Four drops of the dark blue silicone impression material was injected into the transparent silicone polymer on the impression tray. The impression tray was seated on the model of the denture-supporting mucosa. The movement of the four drops caused by the impression flow was visually recorded with the video camera and examined. The result for the flat tray showed that the impression material moved from inside to the outside. It was also shown that the speed of the moved impression material increased as the seating of the impression tray advanced. The results for the relief tray and the escape hole tray showed the effect of the relief and the escape hole prepared to the impression tray on the speed and the direction of the flow of the impression material.

  15. Visual agnosia.

    PubMed

    Biran, I; Coslett, H B

    2003-11-01

    The visual agnosias are an intriguing class of clinical phenomena that have important implications for current theories of high-level vision. Visual agnosia is defined as impaired object recognition that cannot be attributed to visual loss, language impairment, or a general mental decline. At least in some instances, agnostic patients generate an adequate internal representation of the stimulus but fail to recognize it. In this review, we begin by describing the classic works related to the visual agnosias, followed by a description of the major clinical variants and their occurrence in degenerative disorders. In keeping with the theme of this issue, we then discuss recent contributions to this domain. Finally, we present evidence from functional imaging studies to support the clinical distinction between the various types of visual agnosias.

  16. Visual cognition

    PubMed Central

    Cavanagh, Patrick

    2011-01-01

    Visual cognition, high-level vision, mid-level vision and top-down processing all refer to decision-based scene analyses that combine prior knowledge with retinal input to generate representations. The label “visual cognition” is little used at present, but research and experiments on mid- and high-level, inference-based vision have flourished, becoming in the 21st century a significant, if often understated part, of current vision research. How does visual cognition work? What are its moving parts? This paper reviews the origins and architecture of visual cognition and briefly describes some work in the areas of routines, attention, surfaces, objects, and events (motion, causality, and agency). Most vision scientists avoid being too explicit when presenting concepts about visual cognition, having learned that explicit models invite easy criticism. What we see in the literature is ample evidence for visual cognition, but few or only cautious attempts to detail how it might work. This is the great unfinished business of vision research: at some point we will be done with characterizing how the visual system measures the world and we will have to return to the question of how vision constructs models of objects, surfaces, scenes, and events. PMID:21329719

  17. Visual impairment.

    PubMed

    Ellenberger, Carl

    2016-01-01

    This chapter can guide the use of imaging in the evaluation of common visual syndromes: transient visual disturbance, including migraine and amaurosis fugax; acute optic neuropathy complicating multiple sclerosis, neuromyelitis optica spectrum disorder, Leber hereditary optic neuropathy, and Susac syndrome; papilledema and pseudotumor cerebri syndrome; cerebral disturbances of vision, including posterior cerebral arterial occlusion, posterior reversible encephalopathy, hemianopia after anterior temporal lobe resection, posterior cortical atrophy, and conversion blindness. Finally, practical efforts in visual rehabilitation by sensory substitution for blind patients can improve their lives and disclose new information about the brain. PMID:27430448

  18. Observations of Periodic Comet 2P/Encke: Physical Properties of the Nucleus and First Visual-Wavelength Detection of Its Dust Trail

    NASA Technical Reports Server (NTRS)

    Lowry, Stephen C.; Weissman, Paul R.; Sykes, Mark V.; Reach, William T.

    2003-01-01

    We are conducting an observational program designed to determine the overall distributions of size, shape, rotation period, and surface characteristics of cometary nuclei. Here, we present results from a study of the Jupiter- family comet 2P/Encke based on observations from Steward Observatory's 2.3m Bok Telescope at Kitt Peak. This comet has been observed extensively in the past and was one of the primary flyby targets of the recently failed CONTOUR mission.

  19. Visual cognition

    SciTech Connect

    Pinker, S.

    1985-01-01

    This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

  20. Visual search.

    PubMed

    Chan, Louis K H; Hayward, William G

    2013-07-01

    Visual search is the act of looking for a predefined target among other objects. This task has been widely used as an experimental paradigm to study visual attention, and because of its influence has also become a subject of research itself. When used as a paradigm, visual search studies address questions including the nature, function, and limits of preattentive processing and focused attention. As a subject of research, visual search studies address the role of memory in search, the procedures involved in search, and factors that affect search performance. In this article, we review major theories of visual search, the ways in which preattentive information is used to guide attentional allocation, the role of memory, and the processes and decisions involved in its successful completion. We conclude by summarizing the current state of knowledge about visual search and highlight some unresolved issues. WIREs Cogn Sci 2013, 4:415-429. doi: 10.1002/wcs.1235 The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.

  1. An Empirical Study on Using Visual Embellishments in Visualization.

    PubMed

    Borgo, R; Abdul-Rahman, A; Mohamed, F; Grant, P W; Reppa, I; Floridi, L; Chen, Min

    2012-12-01

    In written and spoken communications, figures of speech (e.g., metaphors and synecdoche) are often used as an aid to help convey abstract or less tangible concepts. However, the benefits of using rhetorical illustrations or embellishments in visualization have so far been inconclusive. In this work, we report an empirical study to evaluate hypotheses that visual embellishments may aid memorization, visual search and concept comprehension. One major departure from related experiments in the literature is that we make use of a dual-task methodology in our experiment. This design offers an abstraction of typical situations where viewers do not have their full attention focused on visualization (e.g., in meetings and lectures). The secondary task introduces "divided attention", and makes the effects of visual embellishments more observable. In addition, it also serves as additional masking in memory-based trials. The results of this study show that visual embellishments can help participants better remember the information depicted in visualization. On the other hand, visual embellishments can have a negative impact on the speed of visual search. The results show a complex pattern as to the benefits of visual embellishments in helping participants grasp key concepts from visualization.

  2. Visual Prosthesis

    PubMed Central

    Schiller, Peter H.; Tehovnik, Edward J.

    2009-01-01

    There are more than 40 million blind individuals in the world whose plight would be greatly ameliorated by creating a visual prosthetic. We begin by outlining the basic operational characteristics of the visual system as this knowledge is essential for producing a prosthetic device based on electrical stimulation through arrays of implanted electrodes. We then list a series of tenets that we believe need to be followed in this effort. Central among these is our belief that the initial research in this area, which is in its infancy, should first be carried out in animals. We suggest that implantation of area V1 holds high promise as the area is of a large volume and can therefore accommodate extensive electrode arrays. We then proceed to consider coding operations that can effectively convert visual images viewed by a camera to stimulate electrode arrays to yield visual impressions that can provide shape, motion and depth information. We advocate experimental work that mimics electrical stimulation effects non-invasively in sighted human subjects using a camera from which visual images are converted into displays on a monitor akin to those created by electrical stimulation. PMID:19065857

  3. Snowflake Visualization

    NASA Astrophysics Data System (ADS)

    Bliven, L. F.; Kucera, P. A.; Rodriguez, P.

    2010-12-01

    NASA Snowflake Video Imagers (SVIs) enable snowflake visualization at diverse field sites. The natural variability of frozen precipitation is a complicating factor for remote sensing retrievals in high latitude regions. Particle classification is important for understanding snow/ice physics, remote sensing polarimetry, bulk radiative properties, surface emissivity, and ultimately, precipitation rates and accumulations. Yet intermittent storms, low temperatures, high winds, remote locations and complex terrain can impede us from observing falling snow in situ. SVI hardware and software have some special features. The standard camera and optics yield 8-bit gray-scale images with resolution of 0.05 x 0.1 mm, at 60 frames per second. Gray-scale images are highly desirable because they display contrast that aids particle classification. Black and white (1-bit) systems display no contrast, so there is less information to recognize particle types, which is particularly burdensome for aggregates. Data are analyzed at one-minute intervals using NASA's Precipitation Link Software that produces (a) Particle Catalogs and (b) Particle Size Distributions (PSDs). SVIs can operate nearly continuously for long periods (e.g., an entire winter season), so natural variability can be documented. Let’s summarize results from field studies this past winter and review some recent SVI enhancements. During the winter of 2009-2010, SVIs were deployed at two sites. One SVI supported weather observations during the 2010 Winter Olympics and Paralympics. It was located close to the summit (Roundhouse) of Whistler Mountain, near the town of Whistler, British Columbia, Canada. In addition, two SVIs were located at the King City Weather Radar Station (WKR) near Toronto, Ontario, Canada. Access was prohibited to the SVI on Whistler Mountain during the Olympics due to security concerns. So to meet the schedule for daily data products, we operated the SVI by remote control. We also upgraded the

  4. Visual cognition

    SciTech Connect

    Pinker, S.

    1985-01-01

    This collection of research papers on visual cognition first appeared as a special issue of Cognition: International Journal of Cognitive Science. The study of visual cognition has seen enormous progress in the past decade, bringing important advances in our understanding of shape perception, visual imagery, and mental maps. Many of these discoveries are the result of converging investigations in different areas, such as cognitive and perceptual psychology, artificial intelligence, and neuropsychology. This volume is intended to highlight a sample of work at the cutting edge of this research area for the benefit of students and researchers in a variety of disciplines. The tutorial introduction that begins the volume is designed to help the nonspecialist reader bridge the gap between the contemporary research reported here and earlier textbook introductions or literature reviews.

  5. Visualizing thought.

    PubMed

    Tversky, Barbara

    2011-07-01

    Depictive expressions of thought predate written language by thousands of years. They have evolved in communities through a kind of informal user testing that has refined them. Analyzing common visual communications reveals consistencies that illuminate how people think as well as guide design; the process can be brought into the laboratory and accelerated. Like language, visual communications abstract and schematize; unlike language, they use properties of the page (e.g., proximity and place: center, horizontal/up-down, vertical/left-right) and the marks on it (e.g., dots, lines, arrows, boxes, blobs, likenesses, symbols) to convey meanings. The visual expressions of these meanings (e.g., individual, category, order, relation, correspondence, continuum, hierarchy) have analogs in language, gesture, and especially in the patterns that are created when people design the world around them, arranging things into piles and rows and hierarchies and arrays, spatial-abstraction-action interconnections termed spractions. The designed world is a diagram.

  6. Visual geography

    USGS Publications Warehouse

    ,; ,; ,

    1991-01-01

    Maps are, among other things, a way of making geography visual. They are world views, ways of thinking, and ways of communicating. They depict our world and guide us through it. Visual Geography probes the essence of maps and mapmaking. It follows the story of cartography through the millennia, across the globe, and beyond the solar system. It includes some of the world's most beautiful and enduring maps, some of its most historic - a map in Columbus' hand, the map that was carried to the Moon, the first map to show America - and it examines the urge to map, to measure our world, and to record it graphically.

  7. Visual Hallucinations

    PubMed Central

    Cummings, Jeffrey L.; Miller, Bruce L.

    1987-01-01

    Visual hallucinations occur in diverse clinical circumstances including ophthalmologic diseases, neurologic disorders, toxic and metabolic disorders and idiopathic psychiatric illnesses. Their content, duration and timing relate to their cause and provide useful differential diagnostic information. Hallucinations must be distinguished from delusions and confabulation. A systematic approach to differentiating among hallucinatory syndromes may improve diagnostic accuracy. ImagesFigure 2. PMID:3825109

  8. Visualizing inequality

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2016-07-01

    The study of socioeconomic inequality is of substantial importance, scientific and general alike. The graphic visualization of inequality is commonly conveyed by Lorenz curves. While Lorenz curves are a highly effective statistical tool for quantifying the distribution of wealth in human societies, they are less effective a tool for the visual depiction of socioeconomic inequality. This paper introduces an alternative to Lorenz curves-the hill curves. On the one hand, the hill curves are a potent scientific tool: they provide detailed scans of the rich-poor gaps in human societies under consideration, and are capable of accommodating infinitely many degrees of freedom. On the other hand, the hill curves are a powerful infographic tool: they visualize inequality in a most vivid and tangible way, with no quantitative skills that are required in order to grasp the visualization. The application of hill curves extends far beyond socioeconomic inequality. Indeed, the hill curves are highly effective 'hyperspectral' measures of statistical variability that are applicable in the context of size distributions at large. This paper establishes the notion of hill curves, analyzes them, and describes their application in the context of general size distributions.

  9. [Neuropsychological approach to visual attention].

    PubMed

    Suzuki, Kyoko

    2007-01-01

    Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task. PMID:17354375

  10. [Neuropsychological approach to visual attention].

    PubMed

    Suzuki, Kyoko

    2007-01-01

    Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task. PMID:17228775

  11. Visual direction finding by fishes

    NASA Technical Reports Server (NTRS)

    Waterman, T. H.

    1972-01-01

    The use of visual orientation, in the absence of landmarks, for underwater direction finding exercises by fishes is reviewed. Celestial directional clues observed directly near the water surface or indirectly at an asymptatic depth are suggested as possible orientation aids.

  12. Visualizing Progress

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Reality Capture Technologies, Inc. is a spinoff company from Ames Research Center. Offering e-business solutions for optimizing management, design and production processes, RCT uses visual collaboration environments (VCEs) such as those used to prepare the Mars Pathfinder mission.The product, 4-D Reality Framework, allows multiple users from different locations to manage and share data. The insurance industry is one targeted commercial application for this technology.

  13. Personalized visual aesthetics

    NASA Astrophysics Data System (ADS)

    Vessel, Edward A.; Stahl, Jonathan; Maurer, Natalia; Denker, Alexander; Starr, G. G.

    2014-02-01

    How is visual information linked to aesthetic experience, and what factors determine whether an individual finds a particular visual experience pleasing? We have previously shown that individuals' aesthetic responses are not determined by objective image features but are instead a function of internal, subjective factors that are shaped by a viewers' personal experience. Yet for many classes of stimuli, culturally shared semantic associations give rise to similar aesthetic taste across people. In this paper, we investigated factors that govern whether a set of observers will agree in which images are preferred, or will instead exhibit more "personalized" aesthetic preferences. In a series of experiments, observers were asked to make aesthetic judgments for different categories of visual stimuli that are commonly evaluated in an aesthetic manner (faces, natural landscapes, architecture or artwork). By measuring agreement across observers, this method was able to reveal instances of highly individualistic preferences. We found that observers showed high agreement on their preferences for images of faces and landscapes, but much lower agreement for images of artwork and architecture. In addition, we found higher agreement for heterosexual males making judgments of beautiful female faces than of beautiful male faces. These results suggest that preferences for stimulus categories that carry evolutionary significance (landscapes and faces) come to rely on similar information across individuals, whereas preferences for artifacts of human culture such as architecture and artwork, which have fewer basic-level category distinctions and reduced behavioral relevance, rely on a more personalized set of attributes.

  14. The Drosophila visual system

    PubMed Central

    Zhu, Yan

    2013-01-01

    A compact genome and a tiny brain make Drosophila the prime model to understand the neural substrate of behavior. The neurogenetic efforts to reveal neural circuits underlying Drosophila vision started about half a century ago, and now the field is booming with sophisticated genetic tools, rich behavioral assays, and importantly, a greater number of scientists joining from different backgrounds. This review will briefly cover the structural anatomy of the Drosophila visual system, the animal’s visual behaviors, the genes involved in assembling these circuits, the new and powerful techniques, and the challenges ahead for ultimately identifying the general principles of biological computation in the brain.   A typical brain utilizes a great many compact neural circuits to collect and process information from the internal biological and external environmental worlds and generates motor commands for observable behaviors. The fruit fly Drosophila melanogaster, despite of its miniature body and tiny brain, can survive in almost any corner of the world.1 It can find food, court mate, fight rival conspecific, avoid predators, and amazingly fly without crashing into trees. Drosophila vision and its underlying neuronal machinery has been a key research model for at least half century for neurogeneticists.2 Given the efforts invested on the visual system, this animal model is likely to offer the first full understanding of how visual information is computed by a multi-cellular organism. Furthermore, research in Drosophila has revealed many genes that play crucial roles in the formation of functional brains across species. The architectural similarities between the visual systems of Drosophila and vertebrate at the molecular, cellular, and network levels suggest new principles discovered at the circuit level on the relationship between neurons and behavior in Drosophila shall also contribute greatly to our understanding of the general principles for how bigger brains work.3

  15. Visual bioethics.

    PubMed

    Lauritzen, Paul

    2008-12-01

    Although images are pervasive in public policy debates in bioethics, few who work in the field attend carefully to the way that images function rhetorically. If the use of images is discussed at all, it is usually to dismiss appeals to images as a form of manipulation. Yet it is possible to speak meaningfully of visual arguments. Examining the appeal to images of the embryo and fetus in debates about abortion and stem cell research, I suggest that bioethicists would be well served by attending much more carefully to how images function in public policy debates. PMID:19085479

  16. Visualizing Internet routing changes.

    PubMed

    Lad, Mohit; Massey, Dan; Zhang, Lixia

    2006-01-01

    Today's Internet provides a global data delivery service to millions of end users and routing protocols play a critical role in this service. It is important to be able to identify and diagnose any problems occurring in Internet routing. However, the Internet's sheer size makes this task difficult. One cannot easily extract out the most important or relevant routing information from the large amounts of data collected from multiple routers. To tackle this problem, we have developed Link-Rank, a tool to visualize Internet routing changes at the global scale. Link-Rank weighs links in a topological graph by the number of routes carried over each link and visually captures changes in link weights in the form of a topological graph with adjustable size. Using Link-Rank, network operators can easily observe important routing changes from massive amounts of routing data, discover otherwise unnoticed routing problems, understand the impact of topological events, and infer root causes of observed routing changes.

  17. Supernova 2013dy in NGC 7250 (Lacerta) = PSN J22181760+4034096

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-07-01

    Announcement of independent discovery of Supernova 2013dy in NGC 7250 = PSN J22181760+4034096, a magnitude-17 (unfiltered CCD) Type-Ia supernova that has brightened to 13.5 (visual). Information based on IAU CBAT CBET 3588 (D. W. E. Green, ed.) and observations submitted to the AAVSO. Discovery details: discovered by Lick Observatory Supernova Search (LOSS), reported by C. Casper et al., 2013 July 10.45 UT, 17.0 U; discovered by Kuniaki Goto (Miyoshi-shi, Hiroshima Prefecture, Japan), communicated by S. Itoh, 2013 July 11.735 UT, ~16 U. Coordinates (2000.0) R.A. = 22 18 17.60, Decl.= +40 34 09.6, SN offset 2.1" west, 24.9" north from the nucleus of NGC 7250. Spectroscopy indicating Type-Ia SN one to two weeks before maximum from three sources: D. D. Balam et al. on Jul 13.31 UT; J.-J. Zhang et al. on Jul 14.75 UT; and W. Zheng et al. on Jul 11.7. Visual and photometric observations requested; data submission to the AAVSO International Database using name SN 2013dy requested. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). See full Alert Notice for more details.

  18. Visualization rhetoric: framing effects in narrative visualization.

    PubMed

    Hullman, Jessica; Diakopoulos, Nicholas

    2011-12-01

    Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels-the data, visual representation, textual annotations, and interactivity-and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation.

  19. Alternative representations of visual space

    NASA Technical Reports Server (NTRS)

    Arditi, Aries

    1989-01-01

    This paper discusses a method for delineating and testing hypotheses about the relationship between the retinal images and the three-dimensional visual space they serve. The method may be used under the conditions of changing eye position, occlusion by structures that are part of or are mounted on the observer, occlusions by environmental objects, defects of the visual field, and variables that alter the focus of environmental imagery on the retinas.

  20. Obituary: Janet Akyüz Mattei, 1943-2004

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.; Willson, Lee Anne

    2004-12-01

    period variables. She accelerated a ten-year project to digitize all of AAVSO's archived as well as current data, without which a century of AAVSO observations would now be nearly inaccessible. In the mid-1970s professional interest in the cataclysmic variables began to ramp up. When she received the first requests for an AAVSO visual observing campaign coordinated with observations by orbiting observatories as well as large ground based telescopes, Janet accepted the invitation as both an opportunity and a challenge. AAVSO observers responded marvelously and, coupled with Janet's astute forecasting of when cataclysmic variables were likely to brighten again, the program emerged as one of the major technical successes of her tenure. Many AAVSO members will never forget their excitement when France Córdova came to our Fall meeting in 1978 to announce to the astronomical world that X-rays from SS Cyg had been detected by HEAO-1 on the first occasion after the satellite reached orbit when AAVSO observers reported that the star was brightening to a maximum. It was a moment of tremendous pride for everyone, most of all for Janet. It was a success that was repeated frequently in over six hundred subsequent coordinated observing runs with various satellites. This success greatly increased the impact of AAVSO on current astronomical research, enhanced its reputation, and also provided a more immediate thrill for the observers than the ongoing commitment to monitor slowly varying stars. The late 1970s and early 1980s were a period of substantial inflation in our nation's economy. Furthermore, staff turnover slowed progress with the data processing work, while observations coming to AAVSO from international variable star organizations and independent observers, especially from behind the iron curtain, were increasing rapidly. Faced with rising costs at the same time additional staff was needed to pursue the data processing problems, Janet reacted characteristically: she began

  1. Why Teach Visual Culture?

    ERIC Educational Resources Information Center

    Passmore, Kaye

    2007-01-01

    Visual culture is a hot topic in art education right now as some teachers are dedicated to teaching it and others are adamant that it has no place in a traditional art class. Visual culture, the author asserts, can include just about anything that is visually represented. Although people often think of visual culture as contemporary visuals such…

  2. Adult Visual Experience Promotes Recovery of Primary Visual Cortex from Long-Term Monocular Deprivation

    ERIC Educational Resources Information Center

    Fischer, Quentin S.; Aleem, Salman; Zhou, Hongyi; Pham, Tony A.

    2007-01-01

    Prolonged visual deprivation from early childhood to maturity is believed to cause permanent visual impairment. However, there have been case reports of substantial improvement of binocular vision in human adults following lifelong visual impairment or deprivation. These observations, together with recent findings of adult ocular dominance…

  3. Canonical Visual Size for Real-World Objects

    ERIC Educational Resources Information Center

    Konkle, Talia; Oliva, Aude

    2011-01-01

    Real-world objects can be viewed at a range of distances and thus can be experienced at a range of visual angles within the visual field. Given the large amount of visual size variation possible when observing objects, we examined how internal object representations represent visual size information. In a series of experiments which required…

  4. [Experimental visual evoked potentials. Interstimuli interval and cortical excitability].

    PubMed

    Díaz Calavia, E; Fernández del Moral, R; Dawid-Milner, S; Jiménez Vargas, J

    1989-01-01

    The excitability of the visual system was studied in ten adult chronic cats. Visual evoked potentials were recorded, using decreasing interstimulus intervals. A decrease of the excitability of the visual system is observed when interstimulus intervals are less than 800 milliseconds. Clinical applications with regard to visual evoked potential recording on comatose patients are suggested.

  5. Visual Data Analysis for Satellites

    NASA Technical Reports Server (NTRS)

    Lau, Yee; Bhate, Sachin; Fitzpatrick, Patrick

    2008-01-01

    The Visual Data Analysis Package is a collection of programs and scripts that facilitate visual analysis of data available from NASA and NOAA satellites, as well as dropsonde, buoy, and conventional in-situ observations. The package features utilities for data extraction, data quality control, statistical analysis, and data visualization. The Hierarchical Data Format (HDF) satellite data extraction routines from NASA's Jet Propulsion Laboratory were customized for specific spatial coverage and file input/output. Statistical analysis includes the calculation of the relative error, the absolute error, and the root mean square error. Other capabilities include curve fitting through the data points to fill in missing data points between satellite passes or where clouds obscure satellite data. For data visualization, the software provides customizable Generic Mapping Tool (GMT) scripts to generate difference maps, scatter plots, line plots, vector plots, histograms, timeseries, and color fill images.

  6. Making memories: the development of long-term visual knowledge in children with visual agnosia.

    PubMed

    Metitieri, Tiziana; Barba, Carmen; Pellacani, Simona; Viggiano, Maria Pia; Guerrini, Renzo

    2013-01-01

    There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study of children with focal lesions of the visual pathways provides a unique opportunity to assess the development of visual memory when perceptual input is degraded. We assessed visual recognition and visual memory in three children with lesions to the visual cortex having occurred in early infancy. We then explored the time course of visual memory impairment in two of them at 2  years and 3.7  years from the initial assessment. All children exhibited apperceptive visual agnosia and visual memory impairment. We observed a longitudinal improvement of visual memory modulated by the structural properties of objects. Our findings indicate that processing of degraded perceptions from birth results in impoverished memories. The dynamic interaction between perception and memory during development might modulate the long-term construction of visual representations, resulting in less severe impairment.

  7. Perceptual visual skills in young highly skilled basketball players.

    PubMed

    Sillero Quintana, Manuel; Refoyo Román, Ignacio; Lorenzo Calvo, Alberto; Sampedro Molinuevo, Javier

    2007-04-01

    A simple method was designed to evaluate visual abilities such as disance visual acuity, binocular horizontal visual field, simple and choice visual reaction times, and stereoscopic vision in skilled 11- to 13-yr.-old basketball players participating in a 15-day summer training camp. On a test battery, visual abilities were monitored in 473 players of the Spanish Basketball Federation over a 5-yr. period. The players showed outstanding scores on distance visual acuity and stereoscopic vision, and good visual reaction times and horizontal visual fields. When scores were compared by sex and age, significant differences on certain visual measures were observed. Many layers showed crossed eye-hand dominance. Visual screening programs may help promote visual health among junior basketball players and could be used for performance training. PMID:17566445

  8. Perceptual visual skills in young highly skilled basketball players.

    PubMed

    Sillero Quintana, Manuel; Refoyo Román, Ignacio; Lorenzo Calvo, Alberto; Sampedro Molinuevo, Javier

    2007-04-01

    A simple method was designed to evaluate visual abilities such as disance visual acuity, binocular horizontal visual field, simple and choice visual reaction times, and stereoscopic vision in skilled 11- to 13-yr.-old basketball players participating in a 15-day summer training camp. On a test battery, visual abilities were monitored in 473 players of the Spanish Basketball Federation over a 5-yr. period. The players showed outstanding scores on distance visual acuity and stereoscopic vision, and good visual reaction times and horizontal visual fields. When scores were compared by sex and age, significant differences on certain visual measures were observed. Many layers showed crossed eye-hand dominance. Visual screening programs may help promote visual health among junior basketball players and could be used for performance training.

  9. Canonical Visual Size for Real-World Objects

    PubMed Central

    Konkle, Talia; Oliva, Aude

    2012-01-01

    Real-world objects can be viewed at a range of distances and thus can be experienced at a range of visual angles within the visual field. Given the large amount of visual size variation possible when observing objects, we examined how internal object representations represent visual size information. In a series of experiments which required observers to access existing object knowledge, we observed that real-world objects have a consistent visual size at which they are drawn, imagined, and preferentially viewed. Importantly, this visual size is proportional to the logarithm of the assumed size of the object in the world, and is best characterized not as a fixed visual angle, but by the ratio of the object and the frame of space around it. Akin to the previous literature on canonical perspective, we term this consistent visual size information the canonical visual size. PMID:20822298

  10. Visuals for Information.

    ERIC Educational Resources Information Center

    Pettersson, Rune

    This report focuses on the visual component of verbo-visual literacy, a communications concept involving the production, transmission, and perception of verbal and visual images. Five current problem areas in verbal-visual research are introduced and discussed: (1) communication (communication models, media consumption, new media, the information…

  11. Spelling: A Visual Skill.

    ERIC Educational Resources Information Center

    Hendrickson, Homer

    1988-01-01

    Spelling problems arise due to problems with form discrimination and inadequate visualization. A child's sequence of visual development involves learning motor control and coordination, with vision directing and monitoring the movements; learning visual comparison of size, shape, directionality, and solidity; developing visual memory or recall;…

  12. Neocortical Rebound Depolarization Enhances Visual Perception

    PubMed Central

    Funayama, Kenta; Ban, Hiroshi; Chan, Allen W.; Matsuki, Norio; Murphy, Timothy H.; Ikegaya, Yuji

    2015-01-01

    Animals are constantly exposed to the time-varying visual world. Because visual perception is modulated by immediately prior visual experience, visual cortical neurons may register recent visual history into a specific form of offline activity and link it to later visual input. To examine how preceding visual inputs interact with upcoming information at the single neuron level, we designed a simple stimulation protocol in which a brief, orientated flashing stimulus was subsequently coupled to visual stimuli with identical or different features. Using in vivo whole-cell patch-clamp recording and functional two-photon calcium imaging from the primary visual cortex (V1) of awake mice, we discovered that a flash of sinusoidal grating per se induces an early, transient activation as well as a long-delayed reactivation in V1 neurons. This late response, which started hundreds of milliseconds after the flash and persisted for approximately 2 s, was also observed in human V1 electroencephalogram. When another drifting grating stimulus arrived during the late response, the V1 neurons exhibited a sublinear, but apparently increased response, especially to the same grating orientation. In behavioral tests of mice and humans, the flashing stimulation enhanced the detection power of the identically orientated visual stimulation only when the second stimulation was presented during the time window of the late response. Therefore, V1 late responses likely provide a neural basis for admixing temporally separated stimuli and extracting identical features in time-varying visual environments. PMID:26274866

  13. Outburst of the recurrent nova V745 Sco

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2014-02-01

    The outburst of the recurrent nova V745 Sco (Nova Sco 1937) by Rod Stubbings (Tetoora Road, VIC, Australia) at visual magnitude 9.0 on 2014 February 6.694 UT is reported. This recurrent nova is fading quickly. Follow-up observations of all types (visual, CCD, DSLR) are strongly encouraged, as is spectroscopy; fast time-series of this nova may be useful to detect possible flaring activity as was observed during the outburst of U Scorpii in 2010. Coincident time-series by multiple observers would be most useful for such a study, with a V-filter being preferred. Observations reported to the AAVSO International Database show V745 Sco at visual mag. 10.2 on 2014 Feb. 07.85833 UT (A. Pearce, Nedlands, W. Australia). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. Previous outbursts occurred in 1937 and 1989. The 1937 outburst was detected in 1958 (in decline at magnitude 11.0 on 1937 May 11.1 UT; outburst had occurred within the previous 19 days) by Lukas Plaut on plates taken by Hendrik van Gent at the Leiden Observatory; the object was announced as Nova Sco 1937 and later assigned the GCVS name V745 Sco. The 1989 outburst was detected on 1989 August 1.55 UT by Mati Morel (MMAT, Thornton, NSW, Australia) at visual magnitude 10.4 and in decline. Dr. Bradley Schaefer (Louisiana State University) reports (2010ApJS..187..275S) in his comprehensive analysis of the 10 known galactic recurrent novae (including V745 Sco) that the median interval between recurrent novae outbursts is 24 years. The interval since the 1989 outburst of V745 Sco is 24.10 years. See the Alert Notice for additional visual and multicolor photometry and for more details.

  14. Saccade Adaptation and Visual Uncertainty

    PubMed Central

    Souto, David; Gegenfurtner, Karl R.; Schütz, Alexander C.

    2016-01-01

    Visual uncertainty may affect saccade adaptation in two complementary ways. First, an ideal adaptor should take into account the reliability of visual information for determining the amount of correction, predicting that increasing visual uncertainty should decrease adaptation rates. We tested this by comparing observers' direction discrimination and adaptation rates in an intra-saccadic-step paradigm. Second, clearly visible target steps may generate a slower adaptation rate since the error can be attributed to an external cause, instead of an internal change in the visuo-motor mapping that needs to be compensated. We tested this prediction by measuring saccade adaptation to different step sizes. Most remarkably, we found little correlation between estimates of visual uncertainty and adaptation rates and no slower adaptation rates with more visible step sizes. Additionally, we show that for low contrast targets backward steps are perceived as stationary after the saccade, but that adaptation rates are independent of contrast. We suggest that the saccadic system uses different position signals for adapting dysmetric saccades and for generating a trans-saccadic stable visual percept, explaining that saccade adaptation is found to be independent of visual uncertainty. PMID:27252635

  15. Saccade Adaptation and Visual Uncertainty.

    PubMed

    Souto, David; Gegenfurtner, Karl R; Schütz, Alexander C

    2016-01-01

    Visual uncertainty may affect saccade adaptation in two complementary ways. First, an ideal adaptor should take into account the reliability of visual information for determining the amount of correction, predicting that increasing visual uncertainty should decrease adaptation rates. We tested this by comparing observers' direction discrimination and adaptation rates in an intra-saccadic-step paradigm. Second, clearly visible target steps may generate a slower adaptation rate since the error can be attributed to an external cause, instead of an internal change in the visuo-motor mapping that needs to be compensated. We tested this prediction by measuring saccade adaptation to different step sizes. Most remarkably, we found little correlation between estimates of visual uncertainty and adaptation rates and no slower adaptation rates with more visible step sizes. Additionally, we show that for low contrast targets backward steps are perceived as stationary after the saccade, but that adaptation rates are independent of contrast. We suggest that the saccadic system uses different position signals for adapting dysmetric saccades and for generating a trans-saccadic stable visual percept, explaining that saccade adaptation is found to be independent of visual uncertainty.

  16. Visual examination apparatus

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

    1976-01-01

    An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location including a projection system for displaying to a patient a series of visual stimuli. A response switch enables him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system thereby provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

  17. Visualizing Structure and Dynamics of Disaccharide Simulations

    SciTech Connect

    Matthews, J. F.; Beckham, G. T.; Himmel, M. E.; Crowley, M. F.

    2012-01-01

    We examine the effect of several solvent models on the conformational properties and dynamics of disaccharides such as cellobiose and lactose. Significant variation in timescale for large scale conformational transformations are observed. Molecular dynamics simulation provides enough detail to enable insight through visualization of multidimensional data sets. We present a new way to visualize conformational space for disaccharides with Ramachandran plots.

  18. Scientific Visualization: A Synthesis of Historical Data.

    ERIC Educational Resources Information Center

    Polland, Mark

    Visualization is the process by which one is able to create and sustain mental images for observation, analysis, and experimentation. This study consists of a compilation of evidence from historical examples that were collected in order to document the importance and the uses of visualization within the realm of scientific investigation.…

  19. Universal visualization platform

    NASA Astrophysics Data System (ADS)

    Gee, Alexander G.; Li, Hongli; Yu, Min; Smrtic, Mary Beth; Cvek, Urska; Goodell, Howie; Gupta, Vivek; Lawrence, Christine; Zhou, Jainping; Chiang, Chih-Hung; Grinstein, Georges G.

    2005-03-01

    Although there are a number of visualization systems to choose from when analyzing data, only a few of these allow for the integration of other visualization and analysis techniques. There are even fewer visualization toolkits and frameworks from which one can develop ones own visualization applications. Even within the research community, scientists either use what they can from the available tools or start from scratch to define a program in which they are able to develop new or modified visualization techniques and analysis algorithms. Presented here is a new general-purpose platform for constructing numerous visualization and analysis applications. The focus of this system is the design and experimentation of new techniques, and where the sharing of and integration with other tools becomes second nature. Moreover, this platform supports multiple large data sets, and the recording and visualizing of user sessions. Here we introduce the Universal Visualization Platform (UVP) as a modern data visualization and analysis system.

  20. Declarative Visualization Queries

    NASA Astrophysics Data System (ADS)

    Pinheiro da Silva, P.; Del Rio, N.; Leptoukh, G. G.

    2011-12-01

    In an ideal interaction with machines, scientists may prefer to write declarative queries saying "what" they want from a machine than to write code stating "how" the machine is going to address the user request. For example, in relational database, users have long relied on specifying queries using Structured Query Language (SQL), a declarative language to request data results from a database management system. In the context of visualizations, we see that users are still writing code based on complex visualization toolkit APIs. With the goal of improving the scientists' experience of using visualization technology, we have applied this query-answering pattern to a visualization setting, where scientists specify what visualizations they want generated using a declarative SQL-like notation. A knowledge enhanced management system ingests the query and knows the following: (1) know how to translate the query into visualization pipelines; and (2) how to execute the visualization pipelines to generate the requested visualization. We define visualization queries as declarative requests for visualizations specified in an SQL like language. Visualization queries specify what category of visualization to generate (e.g., volumes, contours, surfaces) as well as associated display attributes (e.g., color and opacity), without any regards for implementation, thus allowing scientists to remain partially unaware of a wide range of visualization toolkit (e.g., Generic Mapping Tools and Visualization Toolkit) specific implementation details. Implementation details are only a concern for our knowledge-based visualization management system, which uses both the information specified in the query and knowledge about visualization toolkit functions to construct visualization pipelines. Knowledge about the use of visualization toolkits includes what data formats the toolkit operates on, what formats they output, and what views they can generate. Visualization knowledge, which is not

  1. Novel Scientific Visualization Interfaces for Interactive Information Visualization and Sharing

    NASA Astrophysics Data System (ADS)

    Demir, I.; Krajewski, W. F.

    2012-12-01

    As geoscientists are confronted with increasingly massive datasets from environmental observations to simulations, one of the biggest challenges is having the right tools to gain scientific insight from the data and communicate the understanding to stakeholders. Recent developments in web technologies make it easy to manage, visualize and share large data sets with general public. Novel visualization techniques and dynamic user interfaces allow users to interact with data, and modify the parameters to create custom views of the data to gain insight from simulations and environmental observations. This requires developing new data models and intelligent knowledge discovery techniques to explore and extract information from complex computational simulations or large data repositories. Scientific visualization will be an increasingly important component to build comprehensive environmental information platforms. This presentation provides an overview of the trends and challenges in the field of scientific visualization, and demonstrates information visualization and communication tools in the Iowa Flood Information System (IFIS), developed within the light of these challenges. The IFIS is a web-based platform developed by the Iowa Flood Center (IFC) to provide access to and visualization of flood inundation maps, real-time flood conditions, flood forecasts both short-term and seasonal, and other flood-related data for communities in Iowa. The key element of the system's architecture is the notion of community. Locations of the communities, those near streams and rivers, define basin boundaries. The IFIS provides community-centric watershed and river characteristics, weather (rainfall) conditions, and streamflow data and visualization tools. Interactive interfaces allow access to inundation maps for different stage and return period values, and flooding scenarios with contributions from multiple rivers. Real-time and historical data of water levels, gauge heights, and

  2. A Visual Test for Visual "Literacy."

    ERIC Educational Resources Information Center

    Messaris, Paul

    Four different principles of visual manipulation constitute a minimal list of what a visually "literate" viewer should know about, but certain problems exist which are inherent in measuring viewers' awareness of each of them. The four principles are: (1) paraproxemics, or camera work which derives its effectiveness from an analogy to the…

  3. The Visual Analysis of Visual Metaphor.

    ERIC Educational Resources Information Center

    Dake, Dennis M.; Roberts, Brian

    This paper presents an approach to understanding visual metaphor which uses metaphoric analysis and comprehension by graphic and pictorial means. The perceptible qualities of shape, line, form, color, and texture, that make up the visual structure characteristic of any particular shape, configuration, or scene, are called physiognomic properties;…

  4. Head Tracking of Auditory, Visual, and Audio-Visual Targets

    PubMed Central

    Leung, Johahn; Wei, Vincent; Burgess, Martin; Carlile, Simon

    2016-01-01

    The ability to actively follow a moving auditory target with our heads remains unexplored even though it is a common behavioral response. Previous studies of auditory motion perception have focused on the condition where the subjects are passive. The current study examined head tracking behavior to a moving auditory target along a horizontal 100° arc in the frontal hemisphere, with velocities ranging from 20 to 110°/s. By integrating high fidelity virtual auditory space with a high-speed visual presentation we compared tracking responses of auditory targets against visual-only and audio-visual “bisensory” stimuli. Three metrics were measured—onset, RMS, and gain error. The results showed that tracking accuracy (RMS error) varied linearly with target velocity, with a significantly higher rate in audition. Also, when the target moved faster than 80°/s, onset and RMS error were significantly worst in audition the other modalities while responses in the visual and bisensory conditions were statistically identical for all metrics measured. Lastly, audio-visual facilitation was not observed when tracking bisensory targets. PMID:26778952

  5. Accuracy of quantitative visual soil assessment

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Maricke; Heuvelink, Gerard; Stoorvogel, Jetse; Wallinga, Jakob; de Boer, Imke; van Dam, Jos; van Essen, Everhard; Moolenaar, Simon; Verhoeven, Frank; Stoof, Cathelijne

    2016-04-01

    Visual soil assessment (VSA) is a method to assess soil quality visually, when standing in the field. VSA is increasingly used by farmers, farm organisations and companies, because it is rapid and cost-effective, and because looking at soil provides understanding about soil functioning. Often VSA is regarded as subjective, so there is a need to verify VSA. Also, many VSAs have not been fine-tuned for contrasting soil types. This could lead to wrong interpretation of soil quality and soil functioning when contrasting sites are compared to each other. We wanted to assess accuracy of VSA, while taking into account soil type. The first objective was to test whether quantitative visual field observations, which form the basis in many VSAs, could be validated with standardized field or laboratory measurements. The second objective was to assess whether quantitative visual field observations are reproducible, when used by observers with contrasting backgrounds. For the validation study, we made quantitative visual observations at 26 cattle farms. Farms were located at sand, clay and peat soils in the North Friesian Woodlands, the Netherlands. Quantitative visual observations evaluated were grass cover, number of biopores, number of roots, soil colour, soil structure, number of earthworms, number of gley mottles and soil compaction. Linear regression analysis showed that four out of eight quantitative visual observations could be well validated with standardized field or laboratory measurements. The following quantitative visual observations correlated well with standardized field or laboratory measurements: grass cover with classified images of surface cover; number of roots with root dry weight; amount of large structure elements with mean weight diameter; and soil colour with soil organic matter content. Correlation coefficients were greater than 0.3, from which half of the correlations were significant. For the reproducibility study, a group of 9 soil scientists and 7

  6. Visualizer cognitive style enhances visual creativity.

    PubMed

    Palmiero, Massimiliano; Nori, Raffaella; Piccardi, Laura

    2016-02-26

    In the last two decades, interest towards creativity has increased significantly since it was recognized as a skill and as a cognitive reserve and is now always more frequently used in ageing training. Here, the relationships between visual creativity and Visualization-Verbalization cognitive style were investigated. Fifty college students were administered the Creative Synthesis Task aimed at measuring the ability to construct creative objects and the Visualization-Verbalization Questionnaire (VVQ) aimed at measuring the attitude to preferentially use either imagery or verbal strategy while processing information. Analyses showed that only the originality score of inventions was positively predicted by the VVQ score: higher VVQ score (indicating the preference to use imagery) predicted originality of inventions. These results showed that the visualization strategy is involved especially in the originality dimension of creative objects production. In light of neuroimaging results, the possibility that different strategies, such those that involve motor processes, affect visual creativity is also discussed.

  7. Visual data of minor meteor showers limits of the method

    NASA Technical Reports Server (NTRS)

    Rendtel, Jurgen; Koschack, R.

    1992-01-01

    Visual meteor observations are carried out on a regular basis by many experienced observers worldwide, thus supplying information about activity of meteor showers. The limits of the method are determined by the accuracy of the detection of the meteor trail. This study shows that visual meteor observations provide reliable data for an observable hourly rate of greater than or equal to 3.

  8. GABA predicts visual intelligence.

    PubMed

    Cook, Emily; Hammett, Stephen T; Larsson, Jonas

    2016-10-01

    Early psychological researchers proposed a link between intelligence and low-level perceptual performance. It was recently suggested that this link is driven by individual variations in the ability to suppress irrelevant information, evidenced by the observation of strong correlations between perceptual surround suppression and cognitive performance. However, the neural mechanisms underlying such a link remain unclear. A candidate mechanism is neural inhibition by gamma-aminobutyric acid (GABA), but direct experimental support for GABA-mediated inhibition underlying suppression is inconsistent. Here we report evidence consistent with a global suppressive mechanism involving GABA underlying the link between sensory performance and intelligence. We measured visual cortical GABA concentration, visuo-spatial intelligence and visual surround suppression in a group of healthy adults. Levels of GABA were strongly predictive of both intelligence and surround suppression, with higher levels of intelligence associated with higher levels of GABA and stronger surround suppression. These results indicate that GABA-mediated neural inhibition may be a key factor determining cognitive performance and suggests a physiological mechanism linking surround suppression and intelligence. PMID:27495012

  9. Visual similarity is stronger than semantic similarity in guiding visual search for numbers.

    PubMed

    Godwin, Hayward J; Hout, Michael C; Menneer, Tamaryn

    2014-06-01

    Using a visual search task, we explored how behavior is influenced by both visual and semantic information. We recorded participants' eye movements as they searched for a single target number in a search array of single-digit numbers (0-9). We examined the probability of fixating the various distractors as a function of two key dimensions: the visual similarity between the target and each distractor, and the semantic similarity (i.e., the numerical distance) between the target and each distractor. Visual similarity estimates were obtained using multidimensional scaling based on the independent observer similarity ratings. A linear mixed-effects model demonstrated that both visual and semantic similarity influenced the probability that distractors would be fixated. However, the visual similarity effect was substantially larger than the semantic similarity effect. We close by discussing the potential value of using this novel methodological approach and the implications for both simple and complex visual search displays.

  10. Visualizing Knowledge Domains.

    ERIC Educational Resources Information Center

    Borner, Katy; Chen, Chaomei; Boyack, Kevin W.

    2003-01-01

    Reviews visualization techniques for scientific disciplines and information retrieval and classification. Highlights include historical background of scientometrics, bibliometrics, and citation analysis; map generation; process flow of visualizing knowledge domains; measures and similarity calculations; vector space model; factor analysis;…

  11. Conjunctive visual forms.

    PubMed

    Weaver, Chris

    2009-01-01

    Visual exploration of multidimensional data is a process of isolating and extracting relationships within and between dimensions. Coordinated multiple view approaches are particularly effective for visual exploration because they support precise expression of heterogeneous multidimensional queries using simple interactions. Recent visual analytics research has made significant progress in identifying and understanding patterns of composed views and coordinations that support fast, flexible, and open-ended data exploration. What is missing is formalization of the space of expressible queries in terms of visual representation and interaction. This paper introduces the Conjunctive Visual Form model in which visual exploration consists of interactively-driven sequences of transitions between visual states that correspond to conjunctive normal forms in boolean logic. The model predicts several new and useful ways to extend the space of rapidly expressible queries through addition of simple interactive capabilities to existing compositional patterns. Two recent related visual tools offer a subset of these capabilities, providing a basis for conjecturing about such extensions.

  12. Interactive visualization of vegetation dynamics

    USGS Publications Warehouse

    Reed, B.C.; Swets, D.; Bard, L.; Brown, J.; Rowland, J.

    2001-01-01

    Satellite imagery provides a mechanism for observing seasonal dynamics of the landscape that have implications for near real-time monitoring of agriculture, forest, and range resources. This study illustrates a technique for visualizing timely information on key events during the growing season (e.g., onset, peak, duration, and end of growing season), as well as the status of the current growing season with respect to the recent historical average. Using time-series analysis of normalized difference vegetation index (NDVI) data from the advanced very high resolution radiometer (AVHRR) satellite sensor, seasonal dynamics can be derived. We have developed a set of Java-based visualization and analysis tools to make comparisons between the seasonal dynamics of the current year with those from the past twelve years. In addition, the visualization tools allow the user to query underlying databases such as land cover or administrative boundaries to analyze the seasonal dynamics of areas of their own interest. The Java-based tools (data exploration and visualization analysis or DEVA) use a Web-based client-server model for processing the data. The resulting visualization and analysis, available via the Internet, is of value to those responsible for land management decisions, resource allocation, and at-risk population targeting.

  13. Distributed Visualization Project

    NASA Technical Reports Server (NTRS)

    Craig, Douglas; Conroy, Michael; Kickbusch, Tracey; Mazone, Rebecca

    2016-01-01

    Distributed Visualization allows anyone, anywhere to see any simulation at any time. Development focuses on algorithms, software, data formats, data systems and processes to enable sharing simulation-based information across temporal and spatial boundaries without requiring stakeholders to possess highly-specialized and very expensive display systems. It also introduces abstraction between the native and shared data, which allows teams to share results without giving away proprietary or sensitive data. The initial implementation of this capability is the Distributed Observer Network (DON) version 3.1. DON 3.1 is available for public release in the NASA Software Store (https://software.nasa.gov/software/KSC-13775) and works with version 3.0 of the Model Process Control specification (an XML Simulation Data Representation and Communication Language) to display complex graphical information and associated Meta-Data.

  14. ESnet Visualization Widgets

    SciTech Connect

    Gopal Vaswani, Jon Dugan

    2012-07-01

    The ESnet Visualization widgets are various data visualization widgets for use in web browsers to aid in the visualization of computer networks. In particular the widgets are targetted at displaying timeseries and topology data. They were developed for use in the MyESnet portal but are general enough to be used other places. The widgets are built using the d3.js library.

  15. Obituary: Janet Akyüz Mattei, 1943-2004

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.; Willson, Lee Anne

    2004-12-01

    period variables. She accelerated a ten-year project to digitize all of AAVSO's archived as well as current data, without which a century of AAVSO observations would now be nearly inaccessible. In the mid-1970s professional interest in the cataclysmic variables began to ramp up. When she received the first requests for an AAVSO visual observing campaign coordinated with observations by orbiting observatories as well as large ground based telescopes, Janet accepted the invitation as both an opportunity and a challenge. AAVSO observers responded marvelously and, coupled with Janet's astute forecasting of when cataclysmic variables were likely to brighten again, the program emerged as one of the major technical successes of her tenure. Many AAVSO members will never forget their excitement when France Córdova came to our Fall meeting in 1978 to announce to the astronomical world that X-rays from SS Cyg had been detected by HEAO-1 on the first occasion after the satellite reached orbit when AAVSO observers reported that the star was brightening to a maximum. It was a moment of tremendous pride for everyone, most of all for Janet. It was a success that was repeated frequently in over six hundred subsequent coordinated observing runs with various satellites. This success greatly increased the impact of AAVSO on current astronomical research, enhanced its reputation, and also provided a more immediate thrill for the observers than the ongoing commitment to monitor slowly varying stars. The late 1970s and early 1980s were a period of substantial inflation in our nation's economy. Furthermore, staff turnover slowed progress with the data processing work, while observations coming to AAVSO from international variable star organizations and independent observers, especially from behind the iron curtain, were increasing rapidly. Faced with rising costs at the same time additional staff was needed to pursue the data processing problems, Janet reacted characteristically: she began

  16. Right hemispheric dominance of visual phenomena evoked by intracerebral stimulation of the human visual cortex.

    PubMed

    Jonas, Jacques; Frismand, Solène; Vignal, Jean-Pierre; Colnat-Coulbois, Sophie; Koessler, Laurent; Vespignani, Hervé; Rossion, Bruno; Maillard, Louis

    2014-07-01

    Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors. PMID:24733699

  17. Right hemispheric dominance of visual phenomena evoked by intracerebral stimulation of the human visual cortex.

    PubMed

    Jonas, Jacques; Frismand, Solène; Vignal, Jean-Pierre; Colnat-Coulbois, Sophie; Koessler, Laurent; Vespignani, Hervé; Rossion, Bruno; Maillard, Louis

    2014-07-01

    Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors.

  18. Visual examination apparatus

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

    1973-01-01

    An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location is described. The apparatus includes a projection system for displaying to a patient a series of visual stimuli, a response switch enabling him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

  19. Visual Semiotics & Uncertainty Visualization: An Empirical Study.

    PubMed

    MacEachren, A M; Roth, R E; O'Brien, J; Li, B; Swingley, D; Gahegan, M

    2012-12-01

    This paper presents two linked empirical studies focused on uncertainty visualization. The experiments are framed from two conceptual perspectives. First, a typology of uncertainty is used to delineate kinds of uncertainty matched with space, time, and attribute components of data. Second, concepts from visual semiotics are applied to characterize the kind of visual signification that is appropriate for representing those different categories of uncertainty. This framework guided the two experiments reported here. The first addresses representation intuitiveness, considering both visual variables and iconicity of representation. The second addresses relative performance of the most intuitive abstract and iconic representations of uncertainty on a map reading task. Combined results suggest initial guidelines for representing uncertainty and discussion focuses on practical applicability of results.

  20. A Bilateral Advantage for Storage in Visual Working Memory

    ERIC Educational Resources Information Center

    Umemoto, Akina; Drew, Trafton; Ester, Edward F.; Awh, Edward

    2010-01-01

    Various studies have demonstrated enhanced visual processing when information is presented across both visual hemifields rather than in a single hemifield (the "bilateral advantage"). For example, Alvarez and Cavanagh (2005) reported that observers were able to track twice as many moving visual stimuli when the tracked items were presented…

  1. Automatic Guidance of Visual Attention from Verbal Working Memory

    ERIC Educational Resources Information Center

    Soto, David; Humphreys, Glyn W.

    2007-01-01

    Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize,…

  2. Functional Visual Loss

    PubMed Central

    Bruce, Beau B; Newman, Nancy J

    2010-01-01

    Synopsis Neurologists frequently evaluate patients complaining of vision loss, especially when the patient has been examined by an ophthalmologist who has found no ocular disease. A significant proportion of patients presenting to the neurologist with visual complaints will have non-organic or functional visual loss. While there are examination techniques which can aid in the detection and diagnosis of functional visual loss, the frequency with which functional visual loss occurs concomitantly with organic disease warrants substantial caution on the part of the clinician. Furthermore, purely functional visual loss is never a diagnosis of exclusion, and must be supported by positive findings on examination that demonstrate normal visual function. The relationship of true psychological disease and functional visual loss is unclear and most patients respond well to simple reassurance. PMID:20638000

  3. RAVE: Rapid Visualization Environment

    NASA Technical Reports Server (NTRS)

    Klumpar, D. M.; Anderson, Kevin; Simoudis, Avangelos

    1994-01-01

    Visualization is used in the process of analyzing large, multidimensional data sets. However, the selection and creation of visualizations that are appropriate for the characteristics of a particular data set and the satisfaction of the analyst's goals is difficult. The process consists of three tasks that are performed iteratively: generate, test, and refine. The performance of these tasks requires the utilization of several types of domain knowledge that data analysts do not often have. Existing visualization systems and frameworks do not adequately support the performance of these tasks. In this paper we present the RApid Visualization Environment (RAVE), a knowledge-based system that interfaces with commercial visualization frameworks and assists a data analyst in quickly and easily generating, testing, and refining visualizations. RAVE was used for the visualization of in situ measurement data captured by spacecraft.

  4. A Presentation of Spectacular Visualizations

    NASA Technical Reports Server (NTRS)

    Hasler, Fritz; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The NASA/NOAA/AMS Earth Science Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to Florida and the KSC Visitor's Center. Go back to the early weather satellite images from the 1960s see them contrasted with the latest International global satellite weather movies including killer hurricanes and tornadic thunderstorms. See the latest spectacular images from NASA and the National Oceanic and Atmospheric Administration (NOAA) remote sensing missions like the Geostationary Operational Environmental Satellites (GOES), NOAA, Tropical Rainfall Measuring Mission (TRMM), SeaWiFS, Landsat7, and new Terra which will be visualized with state-of-the art tools. Shown in High Definition TV resolution (2048 x 768 pixels) are visualizations of hurricanes Lenny, Floyd, Georges, Mitch, Fran, and Linda. See visualizations featured on covers of magazines like Newsweek, TIME, National Geographic, Popular Science, and on National and International Network TV. New Digital Earth visualization tools allow us to roam and zoom through massive global images including a Landsat tour of the US, with drill-downs into major cities using one meter resolution spy-satellite technology from the Space Imaging IKONOS satellite. Spectacular new visualizations of the global atmosphere and oceans are shown. See massive dust storms sweeping across Africa. See ocean vortexes and currents that bring up the nutrients to feed tiny plankton and draw the fish, giant whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. The demonstration is interactively driven by a SGI Octane Graphics Supercomputer with dual CPUs, 5 Gigabytes of RAM and Terabyte disk using two projectors across the super sized Universe Theater panoramic screen.

  5. A Presentation of Spectracular Visualizations

    NASA Technical Reports Server (NTRS)

    Hasler, Fritz; Pierce, Hal; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The NASA/NOAA/AMS Earth Science Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to Florida and the KSC Visitor's Center. Go back to the early weather satellite images from the 1960s see them contrasted with the latest International global satellite weather movies including killer hurricanes & tornadic thunderstorms. See the latest spectacular images from NASA and NOAA remote sensing missions like GOES, NOAA, TRMM, SeaWiFS, Landsat7, & new Terra which will be visualized with state-of-the art tools. Shown in High Definition TV resolution (2048 x 768 pixels) are visualizations of hurricanes Lenny, Floyd, Georges, Mitch, Fran and Linda. See visualizations featured on covers of magazines like Newsweek, TIME, National Geographic, Popular Science and on National & International Network TV. New Digital Earth visualization tools allow us to roam & zoom through massive global images including a Landsat tour of the US, with drill-downs into major cities using I m resolution spy-satellite technology from the Space Imaging IKONOS satellite. Spectacular new visualizations of the global atmosphere & oceans are shown. See massive dust storms sweeping across Africa. See ocean vortexes and currents that bring up the nutrients to feed tiny plankton and draw the fish, giant whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. The demonstration is interactively driven by a SGI Octane Graphics Supercomputer with dual CPUs, 5 Gigabytes of RAM and Terabyte disk using two projectors across the super sized Universe Theater panoramic screen.

  6. Visual Search of Mooney Faces.

    PubMed

    Goold, Jessica E; Meng, Ming

    2016-01-01

    Faces spontaneously capture attention. However, which special attributes of a face underlie this effect is unclear. To address this question, we investigate how gist information, specific visual properties and differing amounts of experience with faces affect the time required to detect a face. Three visual search experiments were conducted investigating the rapidness of human observers to detect Mooney face images. Mooney images are two-toned, ambiguous images. They were used in order to have stimuli that maintain gist information but limit low-level image properties. Results from the experiments show: (1) Although upright Mooney faces were searched inefficiently, they were detected more rapidly than inverted Mooney face targets, demonstrating the important role of gist information in guiding attention toward a face. (2) Several specific Mooney face identities were searched efficiently while others were not, suggesting the involvement of specific visual properties in face detection. (3) By providing participants with unambiguous gray-scale versions of the Mooney face targets prior to the visual search task, the targets were detected significantly more efficiently, suggesting that prior experience with Mooney faces improves the ability to extract gist information for rapid face detection. However, a week of training with Mooney face categorization did not lead to even more efficient visual search of Mooney face targets. In summary, these results reveal that specific local image properties cannot account for how faces capture attention. On the other hand, gist information alone cannot account for how faces capture attention either. Prior experience facilitates the effect of gist on visual search of faces; making faces a special object category for guiding attention.

  7. Crossmodal enhancement of visual orientation discrimination by looming sounds requires functional activation of primary visual areas: a case study.

    PubMed

    Cecere, Roberto; Romei, Vincenzo; Bertini, Caterina; Làdavas, Elisabetta

    2014-04-01

    Approaching or looming sounds are salient, potentially threatening stimuli with particular impact on visual processing. The early crossmodal effects by looming sounds (Romei, Murray, Cappe, & Thut, 2009) and their selective impact on visual orientation discrimination (Leo, Romei, Freeman, Ladavas, & Driver, 2011) suggest that these multisensory interactions may take place already within low-level visual cortices. To investigate this hypothesis, we tested a patient (SDV) with bilateral occipital lesion and spared residual portions of V1/V2. Accordingly, SDV׳s visual perimetry revealed blindness of the central visual field with some residual peripheral vision. In two experiments we tested for the influence of looming vs. receding and stationary sounds on SDV׳s line orientation discrimination (orientation discrimination experiment) and visual detection abilities (detection experiment) in the preserved or blind portions of the visual field, corresponding to spared and lesioned areas of V1, respectively. In the visual orientation discrimination experiment we found that SDV visual orientation sensitivity significantly improved for visual targets paired with looming sounds but only for lines presented in the partially preserved visual field. In the visual detection experiment, where SDV was required to simply detect the same stimuli presented in the orientation discrimination experiment, a generalised sound-induced visual improvement both in the intact and in blind portion of the visual field was observed. These results provide direct evidence that early visual areas are critically involved in crossmodal modulation of visual orientation sensitivity by looming sounds. Thus, a lesion in V1 prevents the enhancement of visual orientation sensitivity. In contrast, the same lesion does not prevent the visual detection enhancement by a sound, probably due to alternative visual pathways (e.g. retino-colliculo-extrastriate) which are usually spared in these patients and able to

  8. Spatial orientation - Visual-vestibular-somatic interaction

    NASA Technical Reports Server (NTRS)

    Parker, D. E.; Poston, R. L.; Gulledge, W. L.

    1983-01-01

    The compensation signals from somatosensory and vestibular receptors, which act to compensate for disturbances produced by the displacement of our eyes relative to other parts of our bodies and for visual disturbances such as tilted frames or moving visual fields, are investigated. Disturbances were evoked by tilting the head and by rotating a large visual display, while compensation signals related to gravity were altered by placing the subjects horizontally on a board or seating them vertically. The first experiment studied the effects of visual disturbance on the ability of supine observers to set a line to the longitudinal body axis while the head was tilted toward one shoulder or while the head was straight. Results showed that the effects of the visual disturbance were greater when the head was tilted than when it was straight, which indicates that the effects of visual disturbance were greater for a task that required compensation. The second experiment compared the performance of supine and erect observers. No differences were found between the performance of observers on a task requiring the use of compensation signals under these two conditions, which suggests that the enrichment of compensatory signals did not reduce the effects of visual disturbancs.

  9. Gamma Oscillations and Visual Binding

    NASA Astrophysics Data System (ADS)

    Robinson, Peter A.; Kim, Jong Won

    2006-03-01

    At the root of visual perception is the mechanism the brain uses to analyze features in a scene and bind related ones together. Experiments show this process is linked to oscillations of brain activity in the 30-100 Hz gamma band. Oscillations at different sites have correlation functions (CFs) that often peak at zero lag, implying simultaneous firing, even when conduction delays are large. CFs are strongest between cells stimulated by related features. Gamma oscillations are studied here by modeling mm-scale patchy interconnections in the visual cortex. Resulting predictions for gamma responses to stimuli account for numerous experimental findings, including why oscillations and zero-lag synchrony are associated, observed connections with feature preferences, the shape of the zero-lag peak, and variations of CFs with attention. Gamma waves are found to obey the Schroedinger equation, opening the possibility of cortical analogs of quantum phenomena. Gamma instabilities are tied to observations of gamma activity linked to seizures and hallucinations.

  10. Similarity relations in visual search predict rapid visual categorization

    PubMed Central

    Mohan, Krithika; Arun, S. P.

    2012-01-01

    How do we perform rapid visual categorization?It is widely thought that categorization involves evaluating the similarity of an object to other category items, but the underlying features and similarity relations remain unknown. Here, we hypothesized that categorization performance is based on perceived similarity relations between items within and outside the category. To this end, we measured the categorization performance of human subjects on three diverse visual categories (animals, vehicles, and tools) and across three hierarchical levels (superordinate, basic, and subordinate levels among animals). For the same subjects, we measured their perceived pair-wise similarities between objects using a visual search task. Regardless of category and hierarchical level, we found that the time taken to categorize an object could be predicted using its similarity to members within and outside its category. We were able to account for several classic categorization phenomena, such as (a) the longer times required to reject category membership; (b) the longer times to categorize atypical objects; and (c) differences in performance across tasks and across hierarchical levels. These categorization times were also accounted for by a model that extracts coarse structure from an image. The striking agreement observed between categorization and visual search suggests that these two disparate tasks depend on a shared coarse object representation. PMID:23092947

  11. Visual motion induces synchronous oscillations in turtle visual cortex.

    PubMed

    Prechtl, J C

    1994-12-20

    In mammalian brains, multielectrode recordings during sensory stimulation have revealed oscillations in different cortical areas that are transiently synchronous. These synchronizations have been hypothesized to support integration of sensory information or represent the operation of attentional mechanisms, but their stimulus requirements and prevalence are still unclear. Here I report an analogous synchronization in a reptilian cortex induced by moving visual stimuli. The synchronization, as measured by the coherence function, applies to spindle-like 20-Hz oscillations recorded with multiple electrodes implanted in the dorsal cortex and the dorsal ventricular ridge of the pond turtle. Additionally, widespread increases in coherence are observed in the 1- to 2-Hz band, and widespread decreases in coherence are seen in the 10- and 30- to 45-Hz bands. The 20-Hz oscillations induced by the moving bar or more natural stimuli are nonstationary and can be sustained for seconds. Early reptile studies may have interpreted similar spindles as electroencephalogram correlates of arousal; however, the absence of these spindles during arousing stimuli in the dark suggests a more specific role in visual processing. Thus, visually induced synchronous oscillations are not unique to the mammalian cortex but also occur in the visual area of the primitive three-layered cortex of reptiles.

  12. Problema vizual'noj registratsii nablyudenij v opticheskoj astronomii XVII-XVIII vekov %t Problem of visual registration of observations in optical astronomy in the 17th-18th centuries

    NASA Astrophysics Data System (ADS)

    Ivanov, Kostantin V.

    This paper attempts to explain the growth of optical astronomy as a result of more general social and cultural change in European life during the two post-Renaissance centuries. It shows how the introduction of optical instruments into astronomical work was accompanied (and partly conditioned) by a few nonastronomical practices, such as collecting unusual things and their images, producing illusionary effects by means of optical devices, manufacturing pictures that could disturb the common visual perception, etc. The paper draws particular attention to the practices of manipulation with visual images that could help to introduce "illusionary" optical knowledge into making "true" drawings from natural objects, including celestial ones. In this way, the formation of new astronomical language can be understood as closely connected to the explicit formulation of technological instructions and legal rules for making copies from natural objects, as well as the general development of printing production and broadening of the market of printed illustrations. These often not enough co-ordinated practices stipulated the shift of optical astronomy into a significant part of seigniorial culture, where it obtained recognition as an essentially new and elite knowledge, associated with particular technological vigilance. During the transition of European monarchies into the absolutist social order, astronomy, on a level with other court services, assumed a shape of professional occupation supplied with certain monetary salaries, a stable position in official hierarchy, and supreme privileges. This was the way by which astronomy merged with the other natural studies and became one of the publicly recognised scientific disciplines.

  13. Infant Visual Attention and Object Recognition

    PubMed Central

    Reynolds, Greg D.

    2015-01-01

    This paper explores the role visual attention plays in the recognition of objects in infancy. Research and theory on the development of infant attention and recognition memory are reviewed in three major sections. The first section reviews some of the major findings and theory emerging from a rich tradition of behavioral research utilizing preferential looking tasks to examine visual attention and recognition memory in infancy. The second section examines research utilizing neural measures of attention and object recognition in infancy as well as research on brain-behavior relations in the early development of attention and recognition memory. The third section addresses potential areas of the brain involved in infant object recognition and visual attention. An integrated synthesis of some of the existing models of the development of visual attention is presented which may account for the observed changes in behavioral and neural measures of visual attention and object recognition that occur across infancy. PMID:25596333

  14. How Infants Learn About the Visual World

    PubMed Central

    Johnson, Scott P.

    2010-01-01

    The visual world of adults consists of objects at various distances, partly occluding one another, substantial and stable across space and time. The visual world of young infants, in contrast, is often fragmented and unstable, consisting not of coherent objects but rather surfaces that move in unpredictable ways. Evidence from computational modeling and from experiments with human infants highlights three kinds of learning that contribute to infants' knowledge of the visual world: learning via association, learning via active assembly, and learning via visual-manual exploration. Infants acquire knowledge by observing objects move in and out of sight, forming associations of these different views. In addition, the infant's own self-produced behavior—oculomotor patterns and manual experience, in particular—are important means by which infants discover and construct their visual world. PMID:21116440

  15. Visual field asymmetries in visual evoked responses

    PubMed Central

    Hagler, Donald J.

    2014-01-01

    Behavioral responses to visual stimuli exhibit visual field asymmetries, but cortical folding and the close proximity of visual cortical areas make electrophysiological comparisons between different stimulus locations problematic. Retinotopy-constrained source estimation (RCSE) uses distributed dipole models simultaneously constrained by multiple stimulus locations to provide separation between individual visual areas that is not possible with conventional source estimation methods. Magnetoencephalography and RCSE were used to estimate time courses of activity in V1, V2, V3, and V3A. Responses to left and right hemifield stimuli were not significantly different. Peak latencies for peripheral stimuli were significantly shorter than those for perifoveal stimuli in V1, V2, and V3A, likely related to the greater proportion of magnocellular input to V1 in the periphery. Consistent with previous results, sensor magnitudes for lower field stimuli were about twice as large as for upper field, which is only partially explained by the proximity to sensors for lower field cortical sources in V1, V2, and V3. V3A exhibited both latency and amplitude differences for upper and lower field responses. There were no differences for V3, consistent with previous suggestions that dorsal and ventral V3 are two halves of a single visual area, rather than distinct areas V3 and VP. PMID:25527151

  16. Attention and visual memory in visualization and computer graphics.

    PubMed

    Healey, Christopher G; Enns, James T

    2012-07-01

    A fundamental goal of visualization is to produce images of data that support visual analysis, exploration, and discovery of novel insights. An important consideration during visualization design is the role of human visual perception. How we "see" details in an image can directly impact a viewer's efficiency and effectiveness. This paper surveys research on attention and visual perception, with a specific focus on results that have direct relevance to visualization and visual analytics. We discuss theories of low-level visual perception, then show how these findings form a foundation for more recent work on visual memory and visual attention. We conclude with a brief overview of how knowledge of visual attention and visual memory is being applied in visualization and graphics. We also discuss how challenges in visualization are motivating research in psychophysics.

  17. Temporal properties of material categorization and material rating: visual vs non-visual material features.

    PubMed

    Nagai, Takehiro; Matsushima, Toshiki; Koida, Kowa; Tani, Yusuke; Kitazaki, Michiteru; Nakauchi, Shigeki

    2015-10-01

    Humans can visually recognize material categories of objects, such as glass, stone, and plastic, easily. However, little is known about the kinds of surface quality features that contribute to such material class recognition. In this paper, we examine the relationship between perceptual surface features and material category discrimination performance for pictures of materials, focusing on temporal aspects, including reaction time and effects of stimulus duration. The stimuli were pictures of objects with an identical shape but made of different materials that could be categorized into seven classes (glass, plastic, metal, stone, wood, leather, and fabric). In a pre-experiment, observers rated the pictures on nine surface features, including visual (e.g., glossiness and transparency) and non-visual features (e.g., heaviness and warmness), on a 7-point scale. In the main experiments, observers judged whether two simultaneously presented pictures were classified as the same or different material category. Reaction times and effects of stimulus duration were measured. The results showed that visual feature ratings were correlated with material discrimination performance for short reaction times or short stimulus durations, while non-visual feature ratings were correlated only with performance for long reaction times or long stimulus durations. These results suggest that the mechanisms underlying visual and non-visual feature processing may differ in terms of processing time, although the cause is unclear. Visual surface features may mainly contribute to material recognition in daily life, while non-visual features may contribute only weakly, if at all.

  18. Visualizing Dynamic Bitcoin Transaction Patterns.

    PubMed

    McGinn, Dan; Birch, David; Akroyd, David; Molina-Solana, Miguel; Guo, Yike; Knottenbelt, William J

    2016-06-01

    This work presents a systemic top-down visualization of Bitcoin transaction activity to explore dynamically generated patterns of algorithmic behavior. Bitcoin dominates the cryptocurrency markets and presents researchers with a rich source of real-time transactional data. The pseudonymous yet public nature of the data presents opportunities for the discovery of human and algorithmic behavioral patterns of interest to many parties such as financial regulators, protocol designers, and security analysts. However, retaining visual fidelity to the underlying data to retain a fuller understanding of activity within the network remains challenging, particularly in real time. We expose an effective force-directed graph visualization employed in our large-scale data observation facility to accelerate this data exploration and derive useful insight among domain experts and the general public alike. The high-fidelity visualizations demonstrated in this article allowed for collaborative discovery of unexpected high frequency transaction patterns, including automated laundering operations, and the evolution of multiple distinct algorithmic denial of service attacks on the Bitcoin network. PMID:27441715

  19. Visualizing Dynamic Bitcoin Transaction Patterns.

    PubMed

    McGinn, Dan; Birch, David; Akroyd, David; Molina-Solana, Miguel; Guo, Yike; Knottenbelt, William J

    2016-06-01

    This work presents a systemic top-down visualization of Bitcoin transaction activity to explore dynamically generated patterns of algorithmic behavior. Bitcoin dominates the cryptocurrency markets and presents researchers with a rich source of real-time transactional data. The pseudonymous yet public nature of the data presents opportunities for the discovery of human and algorithmic behavioral patterns of interest to many parties such as financial regulators, protocol designers, and security analysts. However, retaining visual fidelity to the underlying data to retain a fuller understanding of activity within the network remains challenging, particularly in real time. We expose an effective force-directed graph visualization employed in our large-scale data observation facility to accelerate this data exploration and derive useful insight among domain experts and the general public alike. The high-fidelity visualizations demonstrated in this article allowed for collaborative discovery of unexpected high frequency transaction patterns, including automated laundering operations, and the evolution of multiple distinct algorithmic denial of service attacks on the Bitcoin network.

  20. Visualizing Dynamic Bitcoin Transaction Patterns

    PubMed Central

    McGinn, Dan; Birch, David; Akroyd, David; Molina-Solana, Miguel; Guo, Yike; Knottenbelt, William J.

    2016-01-01

    Abstract This work presents a systemic top-down visualization of Bitcoin transaction activity to explore dynamically generated patterns of algorithmic behavior. Bitcoin dominates the cryptocurrency markets and presents researchers with a rich source of real-time transactional data. The pseudonymous yet public nature of the data presents opportunities for the discovery of human and algorithmic behavioral patterns of interest to many parties such as financial regulators, protocol designers, and security analysts. However, retaining visual fidelity to the underlying data to retain a fuller understanding of activity within the network remains challenging, particularly in real time. We expose an effective force-directed graph visualization employed in our large-scale data observation facility to accelerate this data exploration and derive useful insight among domain experts and the general public alike. The high-fidelity visualizations demonstrated in this article allowed for collaborative discovery of unexpected high frequency transaction patterns, including automated laundering operations, and the evolution of multiple distinct algorithmic denial of service attacks on the Bitcoin network. PMID:27441715

  1. Promoting Visualization Skills through Deconstruction Using Physical Models and a Visualization Activity Intervention

    NASA Astrophysics Data System (ADS)

    Schiltz, Holly Kristine

    Visualization skills are important in learning chemistry, as these skills have been shown to correlate to high ability in problem solving. Students' understanding of visual information and their problem-solving processes may only ever be accessed indirectly: verbalization, gestures, drawings, etc. In this research, deconstruction of complex visual concepts was aligned with the promotion of students' verbalization of visualized ideas to teach students to solve complex visual tasks independently. All instructional tools and teaching methods were developed in accordance with the principles of the theoretical framework, the Modeling Theory of Learning: deconstruction of visual representations into model components, comparisons to reality, and recognition of students' their problemsolving strategies. Three physical model systems were designed to provide students with visual and tangible representations of chemical concepts. The Permanent Reflection Plane Demonstration provided visual indicators that students used to support or invalidate the presence of a reflection plane. The 3-D Coordinate Axis system provided an environment that allowed students to visualize and physically enact symmetry operations in a relevant molecular context. The Proper Rotation Axis system was designed to provide a physical and visual frame of reference to showcase multiple symmetry elements that students must identify in a molecular model. Focus groups of students taking Inorganic chemistry working with the physical model systems demonstrated difficulty documenting and verbalizing processes and descriptions of visual concepts. Frequently asked student questions were classified, but students also interacted with visual information through gestures and model manipulations. In an effort to characterize how much students used visualization during lecture or recitation, we developed observation rubrics to gather information about students' visualization artifacts and examined the effect instructors

  2. Advancing Water Science through Data Visualization

    NASA Astrophysics Data System (ADS)

    Li, X.; Troy, T.

    2014-12-01

    As water scientists, we are increasingly handling larger and larger datasets with many variables, making it easy to lose ourselves in the details. Advanced data visualization will play an increasingly significant role in propelling the development of water science in research, economy, policy and education. It can enable analysis within research and further data scientists' understanding of behavior and processes and can potentially affect how the public, whom we often want to inform, understands our work. Unfortunately for water scientists, data visualization is approached in an ad hoc manner when a more formal methodology or understanding could potentially significantly improve both research within the academy and outreach to the public. Firstly to broaden and deepen scientific understanding, data visualization can allow for more analyzed targets to be processed simultaneously and can represent the variables effectively, finding patterns, trends and relationships; thus it can even explores the new research direction or branch of water science. Depending on visualization, we can detect and separate the pivotal and trivial influential factors more clearly to assume and abstract the original complex target system. Providing direct visual perception of the differences between observation data and prediction results of models, data visualization allows researchers to quickly examine the quality of models in water science. Secondly data visualization can also improve public awareness and perhaps influence behavior. Offering decision makers clearer perspectives of potential profits of water, data visualization can amplify the economic value of water science and also increase relevant employment rates. Providing policymakers compelling visuals of the role of water for social and natural systems, data visualization can advance the water management and legislation of water conservation. By building the publics' own data visualization through apps and games about water

  3. Visual Alert System

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A visual alert system resulted from circuitry developed by Applied Cybernetics Systems for Langley as part of a space related telemetry system. James Campman, Applied Cybernetics president, left the company and founded Grace Industries, Inc. to manufacture security devices based on the Langley technology. His visual alert system combines visual and audible alerts for hearing impaired people. The company also manufactures an arson detection device called the electronic nose, and is currently researching additional applications of the NASA technology.

  4. Scientific Visualization and Computational Science: Natural Partners

    NASA Technical Reports Server (NTRS)

    Uselton, Samuel P.; Lasinski, T. A. (Technical Monitor)

    1995-01-01

    Scientific visualization is developing rapidly, stimulated by computational science, which is gaining acceptance as a third alternative to theory and experiment. Computational science is based on numerical simulations of mathematical models derived from theory. But each individual simulation is like a hypothetical experiment; initial conditions are specified, and the result is a record of the observed conditions. Experiments can be simulated for situations that can not really be created or controlled. Results impossible to measure can be computed.. Even for observable values, computed samples are typically much denser. Numerical simulations also extend scientific exploration where the mathematics is analytically intractable. Numerical simulations are used to study phenomena from subatomic to intergalactic scales and from abstract mathematical structures to pragmatic engineering of everyday objects. But computational science methods would be almost useless without visualization. The obvious reason is that the huge amounts of data produced require the high bandwidth of the human visual system, and interactivity adds to the power. Visualization systems also provide a single context for all the activities involved from debugging the simulations, to exploring the data, to communicating the results. Most of the presentations today have their roots in image processing, where the fundamental task is: Given an image, extract information about the scene. Visualization has developed from computer graphics, and the inverse task: Given a scene description, make an image. Visualization extends the graphics paradigm by expanding the possible input. The goal is still to produce images; the difficulty is that the input is not a scene description displayable by standard graphics methods. Visualization techniques must either transform the data into a scene description or extend graphics techniques to display this odd input. Computational science is a fertile field for visualization

  5. Priming and the guidance by visual and categorical templates in visual search.

    PubMed

    Wilschut, Anna; Theeuwes, Jan; Olivers, Christian N L

    2014-01-01

    Visual search is thought to be guided by top-down templates that are held in visual working memory. Previous studies have shown that a search-guiding template can be rapidly and strongly implemented from a visual cue, whereas templates are less effective when based on categorical cues. Direct visual priming from cue to target may underlie this difference. In two experiments we first asked observers to remember two possible target colors. A postcue then indicated which of the two would be the relevant color. The task was to locate a briefly presented and masked target of the cued color among irrelevant distractor items. Experiment 1 showed that overall search accuracy improved more rapidly on the basis of a direct visual postcue that carried the target color, compared to a neutral postcue that pointed to the memorized color. However, selectivity toward the target feature, i.e., the extent to which observers searched selectively among items of the cued vs. uncued color, was found to be relatively unaffected by the presence of the visual signal. In Experiment 2 we compared search that was based on either visual or categorical information, but now controlled for direct visual priming. This resulted in no differences in overall performance nor selectivity. Altogether the results suggest that perceptual processing of visual search targets is facilitated by priming from visual cues, whereas attentional selectivity is enhanced by a working memory template that can formed from both visual and categorical input. Furthermore, if the priming is controlled for, categorical- and visual-based templates similarly enhance search guidance.

  6. Visual stimulation, 1H MR spectroscopy and fMRI of the human visual pathways.

    PubMed

    Boucard, Christine C; Mostert, Jop P; Cornelissen, Frans W; De Keyser, Jacques; Oudkerk, Matthijs; Sijens, Paul E

    2005-01-01

    The purpose was to assess changes in lactate content and other brain metabolites under visual stimulation in optical chiasm, optic radiations and occipital cortex using multiple voxel MR spectroscopy (MRS). 1H chemical shift imaging (CSI) examinations of transverse planes centered to include the above structures were performed in four subjects at an echo time of 135 ms. Functional MRI (fMRI) was used to confirm the presence of activity in the visual cortex during the visual stimulation. Spectral maps of optical chiasm were of poor quality due to field disturbances caused by nearby large blood vessels and/or eye movements. The optic radiations and the occipital lobe did not show any significant MR spectral change upon visual stimulation, i.e., the peak areas of inositol, choline, creatine, glutamate and N-acetylaspartate were not affected. Reproducible lactate signals were not observed. fMRI confirmed the presence of strong activations in stimulated visual cortex. Prolonged visual stimulation did not cause significant changes in MR spectra. Any signal observed near the 1.33 ppm resonance frequency of the lactate methyl-group was artifactual, originating from lipid signals from outside the volume of interest (VOI). Previous claims about changes in lactate levels in the visual cortex upon visual stimulation may have been based on such erroneous observations. PMID:15480690

  7. Visual perception through the diffusion of light

    NASA Astrophysics Data System (ADS)

    Ung, Timothy

    Human perception of the visual world is limited through the homogeneity of design and the standardization of materials. After constructing a lighting apparatus made of steel and thousands of transparent thread, a small amount of light will be directed onto the apparatus and reflected and refracted multiple times, spreading light over a large area. However, visual perception of the light reflecting and refracting through the apparatus will change according to an observer's location in relation to the apparatus. Ultimately, the goal of this thesis is to engage one's perception of the visual world using properties of transparent materials to maximize the diffusion of light.

  8. Visual screening of muscle ultrasound images in children.

    PubMed

    Brandsma, Rick; Verbeek, Renate J; Maurits, Natasha M; van der Hoeven, Johannes H; Brouwer, Oebele F; den Dunnen, Wilfred F A; Burger, Huibert; Sival, Deborah A

    2014-10-01

    In children, non-invasive muscle ultrasound (MU) imaging has become increasingly important for the detection of neuromuscular pathology, by either quantitative or visual assessment. MU quantification requires time, expertise and equipment. If application of visual MU screening provides reliable results, ubiquitous application could be advocated. Previously, we found that visual MU screening can reliably detect segmental neuromuscular alterations within a patient. Analogously, we reasoned that visual MU screening could discern pathologic MU images from healthy controls. We therefore investigated visual screening results by 20 clinical observers (involving 100 MU images, with [n = 53] and without [n = 47] neuromuscular pathology). MU screening revealed adequate sensitivity, specificity and negative predictive value (85%, 75% and 82%, respectively). MU-experienced observers revealed higher specificity than MU-inexperienced observers (86% vs. 69%, p = 0.005). We conclude that clinical observers can identify neuromuscular pathology by visual screening. To enhance specificity, a secondary view by an expert appears advisory.

  9. Visual cues for landmine detection

    NASA Astrophysics Data System (ADS)

    Staszewski, James J.; Davison, Alan D.; Tischuk, Julia A.; Dippel, David J.

    2007-04-01

    Can human vision supplement the information that handheld landmine detection equipment provides its operators to increase detection rates and reduce the hazard of the task? Contradictory viewpoints exist regarding the viability of visual detection of landmines. Assuming both positions are credible, this work aims to reconcile them by exploring the visual information produced by landmine burial and how any visible signatures change as a function of time in a natural environment. Its objective is to acquire objective, foundational knowledge on which training could be based and subsequently evaluated. A representative set of demilitarized landmines were buried at a field site with bare soil and vegetated surfaces using doctrinal procedures. High resolution photographs of the ground surface were taken for approximately one month starting in April 2006. Photos taken immediately after burial show clearly visible surface signatures. Their features change with time and weather exposure, but the patterns they define persist, as photos taken a month later show. An analysis exploiting the perceptual sensitivity of expert observers showed signature photos to domain experts with instructions to identify the cues and patterns that defined the signatures. Analysis of experts' verbal descriptions identified a small set of easily communicable cues that characterize signatures and their changes over the duration of observation. Findings suggest that visual detection training is viable and has potential to enhance detection capabilities. The photos and descriptions generated offer materials for designing such training and testing its utility. Plans for investigating the generality of the findings, especially potential limiting conditions, are discussed.

  10. Personal Visualization and Personal Visual Analytics.

    PubMed

    Huang, Dandan; Tory, Melanie; Aseniero, Bon Adriel; Bartram, Lyn; Bateman, Scott; Carpendale, Sheelagh; Tang, Anthony; Woodbury, Robert

    2015-03-01

    Data surrounds each and every one of us in our daily lives, ranging from exercise logs, to archives of our interactions with others on social media, to online resources pertaining to our hobbies. There is enormous potential for us to use these data to understand ourselves better and make positive changes in our lives. Visualization (Vis) and visual analytics (VA) offer substantial opportunities to help individuals gain insights about themselves, their communities and their interests; however, designing tools to support data analysis in non-professional life brings a unique set of research and design challenges. We investigate the requirements and research directions required to take full advantage of Vis and VA in a personal context. We develop a taxonomy of design dimensions to provide a coherent vocabulary for discussing personal visualization and personal visual analytics. By identifying and exploring clusters in the design space, we discuss challenges and share perspectives on future research. This work brings together research that was previously scattered across disciplines. Our goal is to call research attention to this space and engage researchers to explore the enabling techniques and technology that will support people to better understand data relevant to their personal lives, interests, and needs.

  11. Personal Visualization and Personal Visual Analytics.

    PubMed

    Huang, Dandan; Tory, Melanie; Aseniero, Bon Adriel; Bartram, Lyn; Bateman, Scott; Carpendale, Sheelagh; Tang, Anthony; Woodbury, Robert

    2015-03-01

    Data surrounds each and every one of us in our daily lives, ranging from exercise logs, to archives of our interactions with others on social media, to online resources pertaining to our hobbies. There is enormous potential for us to use these data to understand ourselves better and make positive changes in our lives. Visualization (Vis) and visual analytics (VA) offer substantial opportunities to help individuals gain insights about themselves, their communities and their interests; however, designing tools to support data analysis in non-professional life brings a unique set of research and design challenges. We investigate the requirements and research directions required to take full advantage of Vis and VA in a personal context. We develop a taxonomy of design dimensions to provide a coherent vocabulary for discussing personal visualization and personal visual analytics. By identifying and exploring clusters in the design space, we discuss challenges and share perspectives on future research. This work brings together research that was previously scattered across disciplines. Our goal is to call research attention to this space and engage researchers to explore the enabling techniques and technology that will support people to better understand data relevant to their personal lives, interests, and needs. PMID:26357073

  12. Observations of Orionids from Bulgaria

    NASA Astrophysics Data System (ADS)

    Dimitrov, Todor; Velkov, Valentin

    2010-01-01

    Presented are results from visual observations of the Orionds and other showers carried out in Bulgaria. Radiant positions of the basic active showers are obtained. Recorded is a possible new radiant in ARI.

  13. Milford Visual Communications Project.

    ERIC Educational Resources Information Center

    Milford Exempted Village Schools, OH.

    This study discusses a visual communications project designed to develop activities to promote visual literacy at the elementary and secondary school levels. The project has four phases: (1) perception of basic forms in the environment, what these forms represent, and how they inter-relate; (2) discovery and communication of more complex…

  14. Visual Arts Research, 1995.

    ERIC Educational Resources Information Center

    Gardner, Nancy C., Ed.; Thompson, Christine, Ed.

    1995-01-01

    This document consists of the two issues of the journal "Visual Arts Research" published in 1995. This journal focuses on the theory and practice of visual arts education from educational, historical, philosophical, and psychological perspectives. Number 1 of this volume includes the following contributions: (1) "Children's Sensitivity to…

  15. Visual Culture of Control

    ERIC Educational Resources Information Center

    Sweeny, Robert W.

    2006-01-01

    Current discussions regarding the notion of visual culture in art educational practice center the actions of the viewer as participant within the networks of visuality common in many contemporary societies. Surveillance technologies and techniques shift this notion of participation from active to passive, from seeing to being seen. This article…

  16. Reading Visual Texts

    ERIC Educational Resources Information Center

    Werner, Walter

    2002-01-01

    Visual images within social studies textbooks need to be actively "read" by students. Drawing on literature from cultural studies, this article suggests three instructional conditions for teaching students to read visual texts. Agency implies that readers have the (1) authority, (2) opportunity and capacity, and (3) community for engaging in the…

  17. Multidimensional Visual Statistical Learning

    ERIC Educational Resources Information Center

    Turk-Browne, Nicholas B.; Isola, Phillip J.; Scholl, Brian J.; Treat, Teresa A.

    2008-01-01

    Recent studies of visual statistical learning (VSL) have demonstrated that statistical regularities in sequences of visual stimuli can be automatically extracted, even without intent or awareness. Despite much work on this topic, however, several fundamental questions remain about the nature of VSL. In particular, previous experiments have not…

  18. Problems Confronting Visual Culture

    ERIC Educational Resources Information Center

    Efland, Arthur D.

    2005-01-01

    A new movement has appeared recommending, in part, that the field of art education should lessen its traditional ties to drawing, painting, and the study of masterpieces to become the study of visual culture. Visual cultural study refers to an all-encompassing category of cultural practice that includes the fine arts but also deals with the study…

  19. Critical Reading: Visual Skills.

    ERIC Educational Resources Information Center

    Adams, Dennis M.

    The computer controlled visual media, particularly television, are becoming an increasingly powerful instrument for the manipulation of thought. Powerful visual images increasingly reflect and shape personal and external reality--politics being one such example--and it is crucial that the viewing public understand the nature of these media…

  20. Program Supports Scientific Visualization

    NASA Technical Reports Server (NTRS)

    Keith, Stephan

    1994-01-01

    Primary purpose of General Visualization System (GVS) computer program is to support scientific visualization of data generated by panel-method computer program PMARC_12 (inventory number ARC-13362) on Silicon Graphics Iris workstation. Enables user to view PMARC geometries and wakes as wire frames or as light shaded objects. GVS is written in C language.

  1. Digital Visual Literacy

    ERIC Educational Resources Information Center

    Spalter, Anne Morgan; van Dam, Andries

    2008-01-01

    Like other literacies (textual literacy, numeracy), digital visual literacy (DVL) is the ability both to create and to understand certain types of information, in this case visual materials created with a computer. DVL is now essential in many daily life and workplace tasks, from looking critically at newspaper images or TV evening news to using a…

  2. Design for Visual Arts.

    ERIC Educational Resources Information Center

    Skeries, Larry

    Experiences suggested within this visual arts packet provide high school students with awareness of visual expression in graphic design, product design, architecture, and crafts. The unit may be used in whole or in part and includes information about art careers and art-related jobs found in major occupational fields. Specific lesson topics…

  3. Visual Factors in Reading

    ERIC Educational Resources Information Center

    Singleton, Chris; Henderson, Lisa-Marie

    2006-01-01

    This article reviews current knowledge about how the visual system recognizes letters and words, and the impact on reading when parts of the visual system malfunction. The physiology of eye and brain places important constraints on how we process text, and the efficient organization of the neurocognitive systems involved is not inherent but…

  4. Infant Visual Recognition Memory

    ERIC Educational Resources Information Center

    Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.

    2004-01-01

    Visual recognition memory is a robust form of memory that is evident from early infancy, shows pronounced developmental change, and is influenced by many of the same factors that affect adult memory; it is surprisingly resistant to decay and interference. Infant visual recognition memory shows (a) modest reliability, (b) good discriminant…

  5. Visual Complexity: A Review

    ERIC Educational Resources Information Center

    Donderi, Don C.

    2006-01-01

    The idea of visual complexity, the history of its measurement, and its implications for behavior are reviewed, starting with structuralism and Gestalt psychology at the beginning of the 20th century and ending with visual complexity theory, perceptual learning theory, and neural circuit theory at the beginning of the 21st. Evidence is drawn from…

  6. Visual Arts Research, 1994.

    ERIC Educational Resources Information Center

    Gardner, Nancy C., Ed.; Thompson, Christine, Ed.

    1994-01-01

    This document consists of the two issues of the journal "Visual Arts in Research" published in 1994. This journal focuses on the theory and practice of visual arts education from educational, historical, philosophical, and psychological perspectives. Number 1 of this volume includes the following contributions: (1) "Zooming in on the Qualitative…

  7. Mandarin Visual Speech Information

    ERIC Educational Resources Information Center

    Chen, Trevor H.

    2010-01-01

    While the auditory-only aspects of Mandarin speech are heavily-researched and well-known in the field, this dissertation addresses its lesser-known aspects: The visual and audio-visual perception of Mandarin segmental information and lexical-tone information. Chapter II of this dissertation focuses on the audiovisual perception of Mandarin…

  8. Visual projection reticle

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1977-01-01

    Small lightweight device visually superimposes visual-sensitivity and response contours on displays and instrument panels. Optical system provides 45 deg arc/diameter field of view; however, special wide-angle optics can be substituted without significant size or weight penalty.

  9. Complicating Visual Culture

    ERIC Educational Resources Information Center

    Daiello, Vicki; Hathaway, Kevin; Rhoades, Mindi; Walker, Sydney

    2006-01-01

    Arguing for complicating the study of visual culture, as advocated by James Elkins, this article explicates and explores Lacanian psychoanalytic theory and pedagogy in view of its implications for art education practice. Subjectivity, a concept of import for addressing student identity and the visual, steers the discussion informed by pedagogical…

  10. Visualizing Qualitative Information

    ERIC Educational Resources Information Center

    Slone, Debra J.

    2009-01-01

    The abundance of qualitative data in today's society and the need to easily scrutinize, digest, and share this information calls for effective visualization and analysis tools. Yet, no existing qualitative tools have the analytic power, visual effectiveness, and universality of familiar quantitative instruments like bar charts, scatter-plots, and…

  11. English 3135: Visual Rhetoric

    ERIC Educational Resources Information Center

    Gatta, Oriana

    2013-01-01

    As an advanced rhetoric and composition doctoral student, I taught Engl 3135: Visual Rhetoric, a three-credit upper-level course offered by the Department of English at Georgia State University. Mary E. Hocks originally designed this course in 2000 to, in her words, "introduce visual information design theories and practices for writers [and]…

  12. Complex Digital Visual Systems

    ERIC Educational Resources Information Center

    Sweeny, Robert W.

    2013-01-01

    This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…

  13. From Visualizing to Proving

    ERIC Educational Resources Information Center

    Zarzycki, Piotr

    2004-01-01

    The benefits of visualizing mathematics by using technology such as TI-92+ and mathematically oriented software (DERIVE 5 and CABRI II) are indisputable. On the basis of some examples we would like to show that visualizing techniques can help students to analyse certain mathematical problems better and give them strong support in finding formal…

  14. Visual Function in Dyslexia.

    ERIC Educational Resources Information Center

    Flax, Nathan

    1968-01-01

    Using published research data, the problem of the seriously retarded reader was examined to determine the role of vision. The most obvious visual factors such as acuity and refractive error did not seem related to the problem. Impairment of visual skills such as fusion and accommodation did seem to contribute to reading difficulty, but such…

  15. Visualizing Social Networks

    NASA Astrophysics Data System (ADS)

    Correa, Carlos D.; Ma, Kwan-Liu

    With today‘s ubiquity and popularity of social network applications, the ability to analyze and understand large networks in an efficient manner becomes critically important. However, as networks become larger and more complex, reasoning about social dynamics via simple statistics is not a feasible option. To overcome these limitations, we can rely on visual metaphors. Visualization nowadays is no longer a passive process that produces images from a set of numbers. Recent years have witnessed a convergence of social network analytics and visualization, coupled with interaction, that is changing the way analysts understand and characterize social networks. In this chapter, we discuss the main goal of visualization and how different metaphors are aimed towards elucidating different aspects of social networks, such as structure and semantics. We also describe a number of methods where analytics and visualization are interwoven towards providing a better comprehension of social structure and dynamics.

  16. Visualization of JPEG Metadata

    NASA Astrophysics Data System (ADS)

    Malik Mohamad, Kamaruddin; Deris, Mustafa Mat

    There are a lot of information embedded in JPEG image than just graphics. Visualization of its metadata would benefit digital forensic investigator to view embedded data including corrupted image where no graphics can be displayed in order to assist in evidence collection for cases such as child pornography or steganography. There are already available tools such as metadata readers, editors and extraction tools but mostly focusing on visualizing attribute information of JPEG Exif. However, none have been done to visualize metadata by consolidating markers summary, header structure, Huffman table and quantization table in a single program. In this paper, metadata visualization is done by developing a program that able to summarize all existing markers, header structure, Huffman table and quantization table in JPEG. The result shows that visualization of metadata helps viewing the hidden information within JPEG more easily.

  17. Picture perception and visual field

    NASA Astrophysics Data System (ADS)

    van Doorn, Andrea J.; de Ridder, Huib; Koenderink, Jan

    2013-03-01

    Looking at a picture fills part of the visual field. In the case of straight photographs there is a notion of the "Field of View" of the camera at the time of exposure. Is there a corresponding notion for the perception of the picture? In most cases the part of the visual field (as measured in degrees) filled by the picture will be quite different from the field of view of the camera. The case of works of arts is even more complicated, there need not even exist a well defined central view point. With several examples we show that there is essentially no notion of a corresponding "field of view" in pictorial perception. This is even the case for drawings in conventional linear perspective. Apparently the "mental eye" of the viewer is often unrelated to the geometry of the camera (or perspective center used in drawing). Observers often substitute templates instead of attempting an analysis of perspective.

  18. Surface flow visualization using indicators

    NASA Technical Reports Server (NTRS)

    Crowder, J. P.

    1982-01-01

    Surface flow visualization using indicators in the cryogenic wind tunnel which requires a fresh look at materials and procedures to accommodate the new test conditions is described. Potential liquid and gaseous indicators are identified. The particular materials illustrate the various requirements an indicator must fulfill. The indicator must respond properly to the flow phenomenon of interest and must be observable. Boundary layer transition is the most important phenomenon for which flow visualization indicators may be employed. The visibility of a particular indicator depends on utilizing various optical or chemical reactions. Gaseous indicators are more difficult to utilize, but because of their diversity may present unusual and useful opportunities. Factors to be considered in selecting an indicator include handling safety, toxicity, potential for contamination of the tunnel, and cost.

  19. Visualization in quantum fluids

    NASA Astrophysics Data System (ADS)

    Lathrop, Daniel

    2015-11-01

    The motion of quantized vortices, which are topological phase defects analogous to crystalline dislocations, substantially controls the dynamics of quantum fluids. Quantized vortices have been observed in superfluid 4He and AMO trapped atom systems, and have been inferred in superfluid 3He and neutron stars. Long-range quantum order underlies a number of related physical phenomena, including superfluidity, trapped-atom Bose-Einstein condensates, superconductivity, ferromagnetism, anti-ferromagnetism, lasers, and the Higgs mechanism. While superfluidity in 4He is one of the first discovered of these phenomena, it is one of the least understood, given that the strongly interacting nature of helium makes theory difficult, and that development of local experimental probes is lagging. The advent of flow visualization of particles that trace quantized vortices has led to many advances. That progress was caused by repeated suggestions from Russ Donnelly, Joe Niemela, and Joe Vinen. Those suggestions led the team, including Gregory P. Bewley, K.R. Sreenivasan and myself, to venture into the quantum fluid realm. We acknowledge the support of NSF DMR/CMP 0906109 and 1407472.

  20. Is Theta Burst Stimulation Applied to Visual Cortex Able to Modulate Peripheral Visual Acuity?

    PubMed Central

    Brückner, Sabrina; Kammer, Thomas

    2014-01-01

    Repetitive transcranial magnetic stimulation is usually applied to visual cortex to explore the effects on cortical excitability. Most researchers therefore concentrate on changes of phosphene threshold, rarely on consequences for visual performance. Thus, we investigated peripheral visual acuity in the four quadrants of the visual field using Landolt C optotypes before and after repetitive stimulation of the visual cortex. We applied continuous and intermittend theta burst stimulation with various stimulation intensities (60%, 80%, 100%, 120% of individual phosphene threshold) as well as monophasic and biphasic 1 Hz stimulation, respectively. As an important result, no serious adverse effects were observed. In particular, no seizure was induced, even with theta burst stimulation applied with 120% of individual phosphene threshold. In only one case stimulation was ceased because the subject reported intolerable pain. Baseline visual acuity decreased over sessions, indicating a continuous training effect. Unexpectedly, none of the applied transcranial magnetic stimulation protocols had an effect on performance: no change in visual acuity was found in any of the four quadrants of the visual field. Binocular viewing as well as the use of peripheral instead of foveal presentation of the stimuli might have contributed to this result. Furthermore, intraindividual variability could have masked the TMS- induced effects on visual acuity. PMID:24914682

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

    PubMed

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

    2014-01-01

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

  2. The picture superiority effect in categorization: visual or semantic?

    PubMed

    Job, R; Rumiati, R; Lotto, L

    1992-09-01

    Two experiments are reported whose aim was to replicate and generalize the results presented by Snodgrass and McCullough (1986) on the effect of visual similarity in the categorization process. For pictures, Snodgrass and McCullough's results were replicated because Ss took longer to discriminate elements from 2 categories when they were visually similar than when they were visually dissimilar. However, unlike Snodgrass and McCullough, an analogous increase was also observed for word stimuli. The pattern of results obtained here can be explained most parsimoniously with reference to the effect of semantic similarity, or semantic and visual relatedness, rather than to visual similarity alone. PMID:1402707

  3. Producing Curious Affects: Visual Methodology as an Affecting and Conflictual Wunderkammer

    ERIC Educational Resources Information Center

    Staunaes, Dorthe; Kofoed, Jette

    2015-01-01

    Digital video cameras, smartphones, internet and iPads are increasingly used as visual research methods with the purpose of creating an affective corpus of data. Such visual methods are often combined with interviews or observations. Not only are visual methods part of the used research methods, the visual products are used as requisites in…

  4. Hemodynamic change in occipital lobe during visual search: visual attention allocation measured with NIRS.

    PubMed

    Kojima, Haruyuki; Suzuki, Takeshi

    2010-01-01

    We examined the changes in regional cerebral blood volume (rCBV) around visual cortex using Near Infrared Spectroscopy (NIRS) when observers attended to visual scenes. The oxygenated and deoxygenated hemoglobin (Oxy-Hb and Deoxy-Hb) concentration changes at occipital lobe were monitored during a dual task. Observers were asked to name a digit superimposed on a scenery picture, while in parallel, they had to detect an on-and-off flickering object in a Change Blindness paradigm. Results showed the typical activation patterns in and around the visual cortex with increases in Oxy-Hb and decreases in Deoxy-Hb. The Oxy-Hb increase doubled when observers could not find the target, as opposed to trials in which they could. The results strongly suggest that active attention to a visual scene enhances Oxy-Hb change much stronger than passive watching, and that attention and Oxy-Hb increases are possibly correlated.

  5. [Subretinal visual implants].

    PubMed

    Stingl, K; Greppmaier, U; Wilhelm, B; Zrenner, E

    2010-12-01

    Visual implants are medical technologies that replace parts of the visual neuronal pathway. The subretinal implant developed by our group is being used in a human trials since 2005 and replaces the function of degenerated photoreceptors by an electronic device in blind patients. The subretinal implant consists of a 70-µm thin microchip with 1500 microphotodiodes each with an amplifier and an electrode with area of 3 mm × 3 mm. The power supply is provided by a subdermal power supply cable. The microchip is implanted under the macula and transforms the light signal into an electrical one, which is referred directly to the bipolar cells. Requirements for a good function of the implant are a preserved function of the inner retina, as well as clear optic media and a good visual acuity in the earlier life. The current technology can mediate a visual field of 10 - 12° and a computed resolution of up to 0.25° visual angle (corresponding to a visual acuity of 63 / 1000 - 80 / 1000) in blind patients. The so far best results from our studies reached a visual acuity of 21 / 1000 in blind retinitis pigmentosa patients. This overview is intended to inform the ophthalmologist about the current state of the technology and help him/her to advise interested patients.

  6. Studies of RV Tauri and SRD Variables

    NASA Astrophysics Data System (ADS)

    Percy, J. R.

    2015-12-01

    AAVSO visual and Johnson V observations of 42 RV Tauri and 30 yellow semiregular (SRD) variables have been time-series analyzed with the AAVSO VSTAR package. The DCDFT routine was used to determine periods and mean amplitudes, and the WWZ (wavelet) routine was used to study changes in the amplitudes of these stars. For almost half of the stars, improved periods and/or classifications were obtained. For others, existing classifications and periods were confirmed or supported. As was previously found for a subset of RV and SRD stars: the pulsation amplitudes vary by factors of up to 10, on median time scales of about 22 pulsation periods for the RV stars, and about 25 pulsation periods for the SRD stars; these two values are not significantly different. This behavior is consistent with that of pulsating red giants and supergiants. The cause of the pulsation amplitude variations remains unknown.

  7. Spatio-temporal Visualization for Environmental Decision Support

    SciTech Connect

    Bhaduri, Budhendra L.; Shankar, Mallikarjun; Sorokine, Alexandre; Ganguly, Auroop R.

    2009-01-01

    Traditional visualization of earth surface features has been addressed through visual exploration, analysis, synthesis, and presentation of observable geospatial data. However, characterizing the changes in their observable and unobservable properties of geospatial features is critical for planning and policy formulation. Recent approaches are addressing modeling and visualization of the temporal dynamics that describe observed and/or predicted physical and socioeconomic processes using vast volumes of earth observation (imagery and other geophysical) data from remote sensor networks. This paper provides an overview of selected geospatial modeling and simulation, exploratory analysis of earth observation data, and high performance visualization research at Oak Ridge National Laboratory for developing novel data driven approaches for geospatial knowledge discovery and visualization relevant to environmental decision support.

  8. Architecture for Teraflop Visualization

    SciTech Connect

    Breckenridge, A.R.; Haynes, R.A.

    1999-04-09

    Sandia Laboratories' computational scientists are addressing a very important question: How do we get insight from the human combined with the computer-generated information? The answer inevitably leads to using scientific visualization. Going one technology leap further is teraflop visualization, where the computing model and interactive graphics are an integral whole to provide computing for insight. In order to implement our teraflop visualization architecture, all hardware installed or software coded will be based on open modules and dynamic extensibility principles. We will illustrate these concepts with examples in our three main research areas: (1) authoring content (the computer), (2) enhancing precision and resolution (the human), and (3) adding behaviors (the physics).

  9. Visualization of electronic density

    DOE PAGES

    Grosso, Bastien; Cooper, Valentino R.; Pine, Polina; Hashibon, Adham; Yaish, Yuval; Adler, Joan

    2015-04-22

    An atom’s volume depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent numerical algorithms and packages to calculate it for other materials. 3D visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. We explore several approaches to 3D charge density visualization, including the extension of an anaglyphic stereo visualization application based on the AViz package to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answering interesting questions about nanotube properties.

  10. What geometric visual hallucinations tell us about the visual cortex.

    PubMed

    Bressloff, Paul C; Cowan, Jack D; Golubitsky, Martin; Thomas, Peter J; Wiener, Matthew C

    2002-03-01

    Many observers see geometric visual hallucinations after taking hallucinogens such as LSD, cannabis, mescaline or psilocybin; on viewing bright flickering lights; on waking up or falling asleep; in "near-death" experiences; and in many other syndromes. Klüver organized the images into four groups called form constants: (I) tunnels and funnels, (II) spirals, (III) lattices, including honeycombs and triangles, and (IV) cobwebs. In most cases, the images are seen in both eyes and move with them. We interpret this to mean that they are generated in the brain. Here, we summarize a theory of their origin in visual cortex (area V1), based on the assumption that the form of the retino-cortical map and the architecture of V1 determine their geometry. (A much longer and more detailed mathematical version has been published in Philosophical Transactions of the Royal Society B, 356 [2001].) We model V1 as the continuum limit of a lattice of interconnected hypercolumns, each comprising a number of interconnected iso-orientation columns. Based on anatomical evidence, we assume that the lateral connectivity between hypercolumns exhibits symmetries, rendering it invariant under the action of the Euclidean group E(2), composed of reflections and translations in the plane, and a (novel) shift-twist action. Using this symmetry, we show that the various patterns of activity that spontaneously emerge when V1's spatially uniform resting state becomes unstable correspond to the form constants when transformed to the visual field using the retino-cortical map. The results are sensitive to the detailed specification of the lateral connectivity and suggest that the cortical mechanisms that generate geometric visual hallucinations are closely related to those used to process edges, contours, surfaces, and textures.

  11. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  12. EDITORIAL: Focus on Visualization in Physics FOCUS ON VISUALIZATION IN PHYSICS

    NASA Astrophysics Data System (ADS)

    Sanders, Barry C.; Senden, Tim; Springel, Volker

    2008-12-01

    cosmology wherein this (in principle invisible) dark matter dominates the cosmic matter content. The advantages of visualization found for simulated data also hold for real world data as well. With the application of computerized acquisition many scientific disciplines are witnessing exponential growth rates of the volume of accumulated raw data, which often makes it daunting to condense the information into a manageable form, a challenge that can be addressed by modern visualization techniques. Such visualizations are also often an enticing way to communicate scientific results to the general public. This need for visualization is especially true in basic science, with its reliance on a benevolent and interested general public that drives the need for high-quality visualizations. Despite the widespread use of visualization, this technology has suffered from a lack of the unifying influence of shared common experiences. As with any emerging technology practitioners have often independently found solutions to similar problems. It is the aim of this focus issue to celebrate the importance of visualization, report on its growing use by the broad community of physicists, including biophysics, chemical physics, geophysics, astrophysics, and medical physics, and provide an opportunity for the diverse community of scientists using visualization to share work in one issue of a journal that itself is in the vanguard of supporting visualization and multimedia. A remarkable breadth and diversity of visualization in physics is to be found in this issue spanning fundamental aspects of relativity theory to computational fluid dynamics. The topics span length scales that are as small as quantum phenomena to the entire observable Universe. We have been impressed by the quality of the submissions and hope that this snap-shot will introduce, inform, motivate and maybe even help to unify visualization in physics. Readers are also directed to the December issue of Physics World which includes

  13. Visual and perceptual consequences of congenital nystagmus.

    PubMed

    Bedell, Harold E

    2006-01-01

    One way to assess the influence of retinal image motion on visual functioning in congenital nystagmus (CN) is to examine the effects of comparable image motion in observers with normal vision. A second approach is to evaluate visual functioning in subjects with CN when the retinal image motion is reduced. Using these approaches, we determined that spatial contrast sensitivity and visual acuity are not limited by the parameters of retinal image motion in some subjects with CN, but rather by a form of amblyopia. Clinical evidence from patients with bilateral refractive amblyopia suggests that a gradual improvement of visual acuity may be possible in persons with CN, if the optimal refractive correction is worn and parameters of the retinal image motion undergo long-term amelioration. PMID:16702076

  14. Propionic acidemia associated with visual hallucinations.

    PubMed

    Shuaib, Taghreed; Al-Hashmi, Nadia; Ghaziuddin, Mohammad; Megdad, Eman; Abebe, Dejene; Al-Saif, Amr; Doubi, Alaa; Aldhalaan, Hesham; Abouzied, Mohei Eldin; Al-Owain, Mohammed

    2012-06-01

    Propionic acidemia, an autosomal recessive disorder, is a common form of organic aciduria resulting from the deficiency of propionyl-CoA carboxylase. It is characterized by frequent and potentially lethal episodes of metabolic acidosis often accompanied by hyperammonemia. A wide range of brain abnormalities have been reported in propionic acidemia. We report recurrent visual hallucinations in 2 children with propionic acidemia. Four visual hallucination events were observed in the 2 patients. Three episodes were preceded by an intercurrent illness, and 2 were associated with mild metabolic decompensation. The 2 events in one patient were associated with a seizure disorder with abnormal electroencephalogram. Brain magnetic resonance imaging showed abnormal basal ganglia and faint temporo-occipital swelling bilaterally. This is probably the first report of visual hallucinations in propionic acidemia and should alert the treating clinicians to look for visual hallucinations in patients with organic acidurias, especially in an unusually anxious child.

  15. Global Precipitation Mission Visualization Tool

    NASA Technical Reports Server (NTRS)

    Schwaller, Mathew

    2011-01-01

    The Global Precipitation Mission (GPM) software provides graphic visualization tools that enable easy comparison of ground- and space-based radar observations. It was initially designed to compare ground radar reflectivity from operational, ground-based, S- and C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation radar instrument. This design is also applicable to other groundbased and space-based radars, and allows both ground- and space-based radar data to be compared for validation purposes. The tool creates an operational system that routinely performs several steps. It ingests satellite radar data (precipitation radar data from TRMM) and groundbased meteorological radar data from a number of sources. Principally, the ground radar data comes from national networks of weather radars (see figure). The data ingested by the visualization tool must conform to the data formats used in GPM Validation Network Geometry-matched data product generation. The software also performs match-ups of the radar volume data for the ground- and space-based data, as well as statistical and graphical analysis (including two-dimensional graphical displays) on the match-up data. The visualization tool software is written in IDL, and can be operated either in the IDL development environment or as a stand-alone executable function.

  16. Alternative Representations of Visual Space

    NASA Astrophysics Data System (ADS)

    Arditi, Aries R.

    1989-09-01

    Although each retinal image is two-dimensional, binocular geometry requires complete representations of field of view to be three-dimensional: the set of visual directions from which light can impinge on either retina can be fully represented in no less than three dimensions. An easily interpretable means of representing environmental space as viewed by a human operator would have wide application in many areas of human factors engineering. This paper discusses a method for delineating and testing hypotheses about the relationship between the retinal images and the three-dimensional visual space they serve, under the conditions of (a) changing eye position, (b) occlusion by structures that are part of or are mounted on the observer such as the bony facial structures, spectacles or headgear, (c) occlusion by environmental objects, (d) defects of the visual field such as the normal blind spot, areas of temporarily reduced visibility due to local adaptation and photopigment bleaching effects, and (c) variables that alter the focus of environmental imagery on the retinas.

  17. EDITORIAL: Focus on Visualization in Physics FOCUS ON VISUALIZATION IN PHYSICS

    NASA Astrophysics Data System (ADS)

    Sanders, Barry C.; Senden, Tim; Springel, Volker

    2008-12-01

    cosmology wherein this (in principle invisible) dark matter dominates the cosmic matter content. The advantages of visualization found for simulated data also hold for real world data as well. With the application of computerized acquisition many scientific disciplines are witnessing exponential growth rates of the volume of accumulated raw data, which often makes it daunting to condense the information into a manageable form, a challenge that can be addressed by modern visualization techniques. Such visualizations are also often an enticing way to communicate scientific results to the general public. This need for visualization is especially true in basic science, with its reliance on a benevolent and interested general public that drives the need for high-quality visualizations. Despite the widespread use of visualization, this technology has suffered from a lack of the unifying influence of shared common experiences. As with any emerging technology practitioners have often independently found solutions to similar problems. It is the aim of this focus issue to celebrate the importance of visualization, report on its growing use by the broad community of physicists, including biophysics, chemical physics, geophysics, astrophysics, and medical physics, and provide an opportunity for the diverse community of scientists using visualization to share work in one issue of a journal that itself is in the vanguard of supporting visualization and multimedia. A remarkable breadth and diversity of visualization in physics is to be found in this issue spanning fundamental aspects of relativity theory to computational fluid dynamics. The topics span length scales that are as small as quantum phenomena to the entire observable Universe. We have been impressed by the quality of the submissions and hope that this snap-shot will introduce, inform, motivate and maybe even help to unify visualization in physics. Readers are also directed to the December issue of Physics World which includes

  18. Air flow visualization

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Smoke Flow Visualization shows the flow of air around a model airfoil at 100 feet per second. Photograph and caption published in Winds of Change, 75th Anniversary NASA publication (page xi), by James Schultz.

  19. X-33 Flight Visualization

    NASA Technical Reports Server (NTRS)

    Laue, Jay H.

    1998-01-01

    The X-33 flight visualization effort has resulted in the integration of high-resolution terrain data with vehicle position and attitude data for planned flights of the X-33 vehicle from its launch site at Edwards AFB, California, to landings at Michael Army Air Field, Utah, and Maelstrom AFB, Montana. Video and Web Site representations of these flight visualizations were produced. In addition, a totally new module was developed to control viewpoints in real-time using a joystick input. Efforts have been initiated, and are presently being continued, for real-time flight coverage visualizations using the data streams from the X-33 vehicle flights. The flight visualizations that have resulted thus far give convincing support to the expectation that the flights of the X-33 will be exciting and significant space flight milestones... flights of this nation's one-half scale predecessor to its first single-stage-to-orbit, fully-reusable launch vehicle system.

  20. Adaptation and visual coding

    PubMed Central

    Webster, Michael A.

    2011-01-01

    Visual coding is a highly dynamic process and continuously adapting to the current viewing context. The perceptual changes that result from adaptation to recently viewed stimuli remain a powerful and popular tool for analyzing sensory mechanisms and plasticity. Over the last decade, the footprints of this adaptation have been tracked to both higher and lower levels of the visual pathway and over a wider range of timescales, revealing that visual processing is much more adaptable than previously thought. This work has also revealed that the pattern of aftereffects is similar across many stimulus dimensions, pointing to common coding principles in which adaptation plays a central role. However, why visual coding adapts has yet to be fully answered. PMID:21602298

  1. Case study: Wildfire visualization

    SciTech Connect

    Ahrens, J.; McCormick, P.; Bossert, J.; Reisner, J.; Winterkamp, J.

    1997-11-01

    The ability to forecast the progress of crisis events would significantly reduce human suffering and loss of life, the destruction of property, and expenditures for assessment and recovery. Los Alamos National Laboratory has established a scientific thrust in crisis forecasting to address this national challenge. In the initial phase of this project, scientists at Los Alamos are developing computer models to predict the spread of a wildfire. Visualization of the results of the wildfire simulation will be used by scientists to assess the quality of the simulation and eventually by fire personnel as a visual forecast of the wildfire`s evolution. The fire personnel and scientists want the visualization to look as realistic as possible without compromising scientific accuracy. This paper describes how the visualization was created, analyzes the tools and approach that was used, and suggests directions for future work and research.

  2. Speaking the Visual Language.

    ERIC Educational Resources Information Center

    Helmken, Charles M.

    1979-01-01

    The development of fine design in alumni publications is traced and the roles of typography, photography, illustration, paper, printing, and color in designing a magazine are discussed. The nature and importance of visual communication are considered. (JMF)

  3. Visualization Design Environment

    SciTech Connect

    Pomplun, A.R.; Templet, G.J.; Jortner, J.N.; Friesen, J.A.; Schwegel, J.; Hughes, K.R.

    1999-02-01

    Improvements in the performance and capabilities of computer software and hardware system, combined with advances in Internet technologies, have spurred innovative developments in the area of modeling, simulation and visualization. These developments combine to make it possible to create an environment where engineers can design, prototype, analyze, and visualize components in virtual space, saving the time and expenses incurred during numerous design and prototyping iterations. The Visualization Design Centers located at Sandia National Laboratories are facilities built specifically to promote the ''design by team'' concept. This report focuses on designing, developing and deploying this environment by detailing the design of the facility, software infrastructure and hardware systems that comprise this new visualization design environment and describes case studies that document successful application of this environment.

  4. Training Visual Attention

    ERIC Educational Resources Information Center

    Mulholland, Thomas B.

    1974-01-01

    The effects of brain waves and alpha rhythms on attentiveness to visual stimuli are discussed, and preliminary research findings and research needs are considered in connection with measuring and training for attention. (LH)

  5. An Hour of Spectacular Visualization

    NASA Technical Reports Server (NTRS)

    Hasler, Arthur F.

    2004-01-01

    The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to the Far East and down to Beijing and Bangkok. Zooms through the Cosmos to the site of the 2004 Summer Olympic games in Athens using 1 m IKONOS "Spy Satellite" data. Contrast the 1972 Apollo 17 "Blue Marble" image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, & Landsat 7, of typhoons/hurricanes and fires in California and around the planet. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual greening of the northern hemisphere land masses and Oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere & Oceans are shown. See the currents and vortexes in the Oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fishermen. See the how the ocean blooms in response to El Nino/La Nina climate changes. The Etheater will be presented using the latest High Definition TV (HDTV) and video projection technology on a large screen. See the global city lights, showing population concentrations in the US, Africa, and Asia observed by the "night-vision" DMSP satellite.

  6. An Hour of Spectacular Visualization

    NASA Technical Reports Server (NTRS)

    Hasler, Arthur F.

    2005-01-01

    The NASA/NOAA Electronic Theater presents Earth science observations and visualizations from space in a historical perspective. Fly in from outer space to Athens and site of the 2004 Summer Olympics and the Far East using 1 m IKONOS "Spy Satellite" data. Contrast the 1972 Apollo 17 "Blue Marble" image of the Earth with the latest US and International global satellite images that allow us to view our Planet from any vantage point. See the latest spectacular images from NASA/NOAA/Commercial remote sensing missions like Terra, GOES, TRMM, SeaWiFS, & Landsat 7, QuickBird of the SE Asia Tsunami, devastation of Hurricane Katrina this year in New Orleans, and the LA/San Diego Fires of 2003. See how High Definition Television (HDTV) is revolutionizing the way we do science communication. Take the pulse of the planet on a daily, annual and 30-year time scale. See daily thunderstorms, the annual blooming of the northern hemisphere land masses and oceans, fires in Africa, dust storms in Iraq, and carbon monoxide exhaust from global burning. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. Spectacular new global visualizations of the observed and simulated atmosphere & oceans are shown. See the currents and vortexes in the oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fishermen. See the how the ocean blooms in response to El Nino/La Nina climate changes. The Etheater will be presented using the latest High Definition TV (HDTV) and video projection technology on a large screen. See city lights around the globe and in your area observed by the "night-vision" DMSP satellite, Also see how Keyhole and Google Maps are using satellite and aerial photography to help you find your house and plan your vacation.

  7. 3D visualization of port simulation.

    SciTech Connect

    Horsthemke, W. H.; Macal, C. M.; Nevins, M. R.

    1999-06-14

    Affordable and realistic three dimensional visualization technology can be applied to large scale constructive simulations such as the port simulation model, PORTSIM. These visualization tools enhance the experienced planner's ability to form mental models of how seaport operations will unfold when the simulation model is implemented and executed. They also offer unique opportunities to train new planners not only in the use of the simulation model but on the layout and design of seaports. Simulation visualization capabilities are enhanced by borrowing from work on interface design, camera control, and data presentation. Using selective fidelity, the designers of these visualization systems can reduce their time and efforts by concentrating on those features which yield the most value for their simulation. Offering the user various observational tools allows the freedom to simply watch or engage in the simulation without getting lost. Identifying the underlying infrastructure or cargo items with labels can provide useful information at the risk of some visual clutter. The PortVis visualization expands the PORTSIM user base which can benefit from the results provided by this capability, especially in strategic planning, mission rehearsal, and training. Strategic planners will immediately reap the benefits of seeing the impact of increased throughput visually without keeping track of statistical data. Mission rehearsal and training users will have an effective training tool to supplement their operational training exercises which are limited in number because of their high costs. Having another effective training modality in this visualization system allows more training to take place and more personnel to gain an understanding of seaport operations. This simulation and visualization training can be accomplished at lower cost than would be possible for the operational training exercises alone. The application of PORTSIM and PortVis will lead to more efficient

  8. Extreme Scale Visual Analytics

    SciTech Connect

    Steed, Chad A; Potok, Thomas E; Pullum, Laura L; Ramanathan, Arvind; Shipman, Galen M; Thornton, Peter E; Potok, Thomas E

    2013-01-01

    Given the scale and complexity of today s data, visual analytics is rapidly becoming a necessity rather than an option for comprehensive exploratory analysis. In this paper, we provide an overview of three applications of visual analytics for addressing the challenges of analyzing climate, text streams, and biosurveilance data. These systems feature varying levels of interaction and high performance computing technology integration to permit exploratory analysis of large and complex data of global significance.

  9. Visualization and data analysis

    SciTech Connect

    Ahrens, James P; Rodgers, David; Springmeyer, Becky

    2010-12-21

    Talk about Visualization and Data Analysis Current State and Exascale challenges. The goal is to update with colleagues our current status in our research. What challenges we need to face, and what future possibilities. Our goal is to propose to approach the problems with the visualization approach operating on the supercomputing platform. This presentation is about the L2 Milestone, we intend to discuss further possibilities of enhancing our results and optimizing our solutions.

  10. Visual air quality simulation techniques

    NASA Astrophysics Data System (ADS)

    Molenar, John V.; Malm, William C.; Johnson, Christopher E.

    Visual air quality is primarily a human perceptual phenomenon beginning with the transfer of image-forming information through an illuminated, scattering and absorbing atmosphere. Visibility, especially the visual appearance of industrial emissions or the degradation of a scenic view, is the principal atmospheric characteristic through which humans perceive air pollution, and is more sensitive to changing pollution levels than any other air pollution effect. Every attempt to quantify economic costs and benefits of air pollution has indicated that good visibility is a highly valued and desired environmental condition. Measurement programs can at best approximate the state of the ambient atmosphere at a few points in a scenic vista viewed by an observer. To fully understand the visual effect of various changes in the concentration and distribution of optically important atmospheric pollutants requires the use of aerosol and radiative transfer models. Communication of the output of these models to scientists, decision makers and the public is best done by applying modern image-processing systems to generate synthetic images representing the modeled air quality conditions. This combination of modeling techniques has been under development for the past 15 yr. Initially, visual air quality simulations were limited by a lack of computational power to simplified models depicting Gaussian plumes or uniform haze conditions. Recent explosive growth in low cost, high powered computer technology has allowed the development of sophisticated aerosol and radiative transfer models that incorporate realistic terrain, multiple scattering, non-uniform illumination, varying spatial distribution, concentration and optical properties of atmospheric constituents, and relative humidity effects on aerosol scattering properties. This paper discusses these improved models and image-processing techniques in detail. Results addressing uniform and non-uniform layered haze conditions in both

  11. Eye movements reset visual perception.

    PubMed

    Paradiso, Michael A; Meshi, Dar; Pisarcik, Jordan; Levine, Samuel

    2012-12-12

    Human vision uses saccadic eye movements to rapidly shift the sensitive foveal portion of our retina to objects of interest. For vision to function properly amidst these ballistic eye movements, a mechanism is needed to extract discrete percepts on each fixation from the continuous stream of neural activity that spans fixations. The speed of visual parsing is crucial because human behaviors ranging from reading to driving to sports rely on rapid visual analysis. We find that a brain signal associated with moving the eyes appears to play a role in resetting visual analysis on each fixation, a process that may aid in parsing the neural signal. We quantified the degree to which the perception of tilt is influenced by the tilt of a stimulus on a preceding fixation. Two key conditions were compared, one in which a saccade moved the eyes from one stimulus to the next and a second simulated saccade condition in which the stimuli moved in the same manner but the subjects did not move their eyes. We find that there is a brief period of time at the start of each fixation during which the tilt of the previous stimulus influences perception (in a direction opposite to the tilt aftereffect)--perception is not instantaneously reset when a fixation starts. Importantly, the results show that this perceptual bias is much greater, with nearly identical visual input, when saccades are simulated. This finding suggests that, in real-saccade conditions, some signal related to the eye movement may be involved in the reset phenomenon. While proprioceptive information from the extraocular muscles is conceivably a factor, the fast speed of the effect we observe suggests that a more likely mechanism is a corollary discharge signal associated with eye movement.

  12. Eye movements reset visual perception.

    PubMed

    Paradiso, Michael A; Meshi, Dar; Pisarcik, Jordan; Levine, Samuel

    2012-01-01

    Human vision uses saccadic eye movements to rapidly shift the sensitive foveal portion of our retina to objects of interest. For vision to function properly amidst these ballistic eye movements, a mechanism is needed to extract discrete percepts on each fixation from the continuous stream of neural activity that spans fixations. The speed of visual parsing is crucial because human behaviors ranging from reading to driving to sports rely on rapid visual analysis. We find that a brain signal associated with moving the eyes appears to play a role in resetting visual analysis on each fixation, a process that may aid in parsing the neural signal. We quantified the degree to which the perception of tilt is influenced by the tilt of a stimulus on a preceding fixation. Two key conditions were compared, one in which a saccade moved the eyes from one stimulus to the next and a second simulated saccade condition in which the stimuli moved in the same manner but the subjects did not move their eyes. We find that there is a brief period of time at the start of each fixation during which the tilt of the previous stimulus influences perception (in a direction opposite to the tilt aftereffect)--perception is not instantaneously reset when a fixation starts. Importantly, the results show that this perceptual bias is much greater, with nearly identical visual input, when saccades are simulated. This finding suggests that, in real-saccade conditions, some signal related to the eye movement may be involved in the reset phenomenon. While proprioceptive information from the extraocular muscles is conceivably a factor, the fast speed of the effect we observe suggests that a more likely mechanism is a corollary discharge signal associated with eye movement. PMID:23241264

  13. Voluntary alteration of visual evoked potentials.

    PubMed

    Bumgartner, J; Epstein, C M

    1982-11-01

    Fifteen normal adults had pattern-shift visual evoked potentials (PSVEPs) using monocular checkerboard pattern reversal. Subjects were instructed to concentrate on the pattern in the first set of trials and then to avoid perceiving it in the second set. Direct, continuous visual observation ensured that the eye remained open and fixed on the pattern. Nonetheless, a third of the subjects could spontaneously alter or obliterate the PSVEP using several maneuvers, including meditation, daydreaming, and convergence. Several could produce shifts in apparent PSVEP latency. With explicit instruction, most subjects could learn to alter their PSVEP by maneuvers that are inapparent even to an observent technician.

  14. Common mechanisms of visual imagery and perception.

    PubMed

    Ishai, A; Sagi, D

    1995-06-23

    Detection of a visual target can be facilitated by flanking visual masks. A similar enhancement in detection thresholds was obtained when observers imagined the previously perceived masks. Imagery-induced facilitation was detected for as long as 5 minutes after observation of the masks by the targeted eye. These results indicated the existence of a low-level (monocular) memory that stores the sensory trace for several minutes and enables reactivation of early representations by higher processes. This memory, with its iconic nature, may subserve the interface between mental images and percepts.

  15. Visual-servoing optical microscopy

    DOEpatents

    Callahan, Daniel E.; Parvin, Bahram

    2009-06-09

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time: quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  16. Visualizing the universe, part 1

    NASA Technical Reports Server (NTRS)

    Geller, M. J.; Huchra, J. P.

    1992-01-01

    These decades are the first in which we can begin to map the universe. Recent surveys reveal patterns in the distribution of galaxies -- patterns coherent on scales of 150 million light years or more. These patterns contrast with the smoothness of the radiation background measured by the COBE satellite. Together these observations challenge our understanding of the origin of galaxies and large-scale structure in the universe. 'Visualizing the universe' is crucial for exploring the 3-dimensional maps, for analyzing them, for comparing the data with simulations, for designing instruments to make deeper maps with new large telescopes, and for sharing the excitement of discovery with the public.

  17. Visual-servoing optical microscopy

    DOEpatents

    Callahan, Daniel E.; Parvin, Bahram

    2011-05-24

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time; quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  18. Visual-servoing optical microscopy

    DOEpatents

    Callahan, Daniel E; Parvin, Bahram

    2013-10-01

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time; quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  19. Visual illusions and hallucinations.

    PubMed

    Kölmel, H W

    1993-08-01

    Visual illusions and hallucinations may accompany a wide variety of disorders with many different aetiologies; therefore, they are non-specific phenomena. Lesions in the visual pathway may be associated with visual misperceptions. In these cases more exact information about the misperceptions--whether they are monocular or binocular, present in the whole visual field or a hemifield--may contribute to diagnostic accuracy and to a more comprehensive understanding of the patient and his state of mind. Illusions such as perseveration, monocular diplopia and polyopia, and dysmorphopsia may also occur in healthy individuals, but they are found most often in patients with epilepsy, migraine and stroke. These phenomena do not permit exact localization and definition of an aetiology, but lesions in the occipital and occipitotemporal regions near the visual pathway are involved in most cases. Hallucinations always represent a pathological form of perception. They are classified as unformed (photopsias) or formed (complex). Photopsias may be described in terms of colour, shape and brightness. Their wide variety makes it difficult, if not impossible, to arrive at an exact description of their aetiology, but it is possible to define their anatomical origin in some cases. Complex hallucinations suggest an occipitotemporal locus. Whether they appear in the whole visual field or in the hemifield may prove decisive in determining pathogenesis. A number of characteristics permit a rough classification of these phenomena. Complex hallucinations accompany physical illness and are susceptible to psychodynamic interpretation.

  20. Quantized visual awareness

    PubMed Central

    Escobar, W. A.

    2013-01-01

    The proposed model holds that, at its most fundamental level, visual awareness is quantized. That is to say that visual awareness arises as individual bits of awareness through the action of neural circuits with hundreds to thousands of neurons in at least the human striate cortex. Circuits with specific topologies will reproducibly result in visual awareness that correspond to basic aspects of vision like color, motion, and depth. These quanta of awareness (qualia) are produced by the feedforward sweep that occurs through the geniculocortical pathway but are not integrated into a conscious experience until recurrent processing from centers like V4 or V5 select the appropriate qualia being produced in V1 to create a percept. The model proposed here has the potential to shift the focus of the search for visual awareness to the level of microcircuits and these likely exist across the kingdom Animalia. Thus establishing qualia as the fundamental nature of visual awareness will not only provide a deeper understanding of awareness, but also allow for a more quantitative understanding of the evolution of visual awareness throughout the animal kingdom. PMID:24319436

  1. Literacy and visual impairment.

    PubMed

    Erickson, Karen A; Hatton, Deborah

    2007-02-01

    Research supporting specific instructional approaches for young children with visual impairments and blindness is limited. There is, however, a growing body of evidence to support the belief that the critical components of emergent and early conventional literacy for children with visual impairments do not differ markedly from those of their sighted peers. Specifically, infants and toddlers with visual impairments and blindness require interactions that support their oral language development, awareness of print or braille, and opportunities to explore writing. Although these very young children are often delayed in developing emergent literacy understandings, the path of their development is consistent with emergent literacy development of sighted children. The research regarding older children with visual impairments and blindness suggests that they too benefit from instruction that emphasizes the critical elements of early literacy instruction for all children. Research also suggests that specific strategies, such as repeated readings, direct instruction in phonics, and big word decoding that emphasizes morphemes, can benefit school-aged children with visual impairments and blindness. Further research is needed if we are to understand fully the most effective approaches to emergent and early literacy instruction for children with visual impairments and blindness, but there is a solid base from which we can begin. PMID:17340383

  2. Visualization Dot Com

    SciTech Connect

    Bethel, Wes

    2000-02-09

    In this article, we explore the seemingly well-worn subject of distance-based, or remote visualization. Current practices in remote visualization tend to clump into two broad categories. One approach, which we'll call render-remote, is to render an image remotely, then transmit the data to the user. Another option, render-local, transfers raw data to the user, where it is then visualized and rendered on the local workstation. With advances in networking and graphics technology, we can explore a class of approaches from a new, third category. With this third category, which we'll called shared, or ''dot com'' visualization, we stand to reap the best of both worlds; minimized data transfers and workstation-accelerated rendering. We will describe a prototype system called Visapult currently under development at Lawrence Berkeley National Laboratory (LBNL) that strikes such a balance, achieving a blended, scalable visualization tool. ''Dot com'' visualization means that remote and local resources collaborate and negotiate, combining capabilities to produce a final product.

  3. Earth and Space Science Electronic Theater: State-of-the-Art Visualization from the Latest Remote Sensing Observations. High Definition Television on the SMM IMAX Screen with Ultra High Performance Projector

    NASA Technical Reports Server (NTRS)

    Hasler, A. F.; Starr, David (Technical Monitor)

    2001-01-01

    Fritz Hasler (NASA/Goddard) will demonstrate the latest Blue Marble Digital Earth technology. We will fly in from space through Terra, Landsat 7, to 1 m Ikonos "Spy Satellite" data to Washington, NYC, Chicago, and LA. You will see animations using the new 1 km global datasets from the EOS Terra satellite. Spectacular new animations from Terra, Landsat 7, and SeaWiFS will be presented. See the latest animations of the super hurricanes like, Floyd, Luis, and Mitch, from GOES & TRMM. See movies assembled using new low cost HDTV nonlinear editing equipment that is revolutionizing the way we communicate scientific results. See climate change in action with Global Land & Ocean productivity changes over the last 20 years. Remote sensing observations of ocean SST, height, winds, color, and El Nino from GOES, AVHRR, SSMI & SeaWiFS are put in context with atmospheric and ocean simulations. Compare symmetrical equatorial eddies observed by GOES with the simulations.

  4. Visual perception in space and time--mapping the visual field of temporal resolution.

    PubMed

    Poggel, Dorothe A; Strasburger, Hans

    2004-01-01

    To characterize temporal aspects of information processing in the human visual field, we studied the topographical distribution of temporal and non-temporal performance parameters in 95 normally sighted subjects. Visual field maps of double-pulse resolution thresholds (DPR) (the minimum detectable temporal gap between two light stimuli) and simple visual reaction times (RT) (measuring the speed of reaction to a light stimulus) were compared to maps of luminance thresholds determined by standard perimetry. Thus, for the first time, the topography of a visual variable without temporal constraints (perimetry) could be compared to visual variables in the temporal domain, with (RT) and without (DPR) motor reaction. The goal of the study was to obtain and to describe the pattern of co-variation of performance indicators. In all three measures, performance was best in the central visual field and dropped significantly towards the periphery. Although the correlation between DPR and RT was significant, shared variance was low, and we observed large topographical differences between these two temporal-performance variables. In contrast, DPR and perimetric thresholds correlated more substantially, and visual field maps were similar. The Gestalt of DPR maps shares characteristics of basic visual processing (e.g., light sensitivity), but it also reflects top-down influences, i.e., from spatial attention. Although the correlation between DPR and RT suggests common characteristics between these two temporal variables, the topographic distributions reveal significant differences, indicating separate underlying processing mechanisms. PMID:15283484

  5. Auditory attention causes visual inattentional blindness.

    PubMed

    Pizzighello, Silvia; Bressan, Paola

    2008-01-01

    When engaged in a visual task, we can fail to detect unexpected events that would otherwise be very noticeable. Here we ask whether a common auditory task, such as that of attending to a verbal stream, can also make us blind to the presence of visual objects that we do not anticipate. In two experiments, one hundred and twenty observers watched a dynamic display while performing either a visual or an auditory attention task, or both simultaneously. When observers were listening to verbal material, in order to either understand it or to remember it (auditory task), their probability of detecting an unexpected visual object was no higher than when they were counting bounces of moving items (visual task), although in the former case the observers' eyes and attention could move around the display freely rather than remaining focused on tracked items. Previous research has shown that attending to verbal material does not affect responses to lights flashing at irregular intervals, suggesting that driving performance is not hampered by listening. The lights, however, were expected. Our data imply that listening to the radio while driving, or to a portable audio player while walking or biking, can impair our reactions to objects or events that we do not expect. PMID:18686705

  6. Visualization of ocean forecast in BYTHOS

    NASA Astrophysics Data System (ADS)

    Zhuk, E.; Zodiatis, G.; Nikolaidis, A.; Stylianou, S.; Karaolia, A.

    2016-08-01

    The Cyprus Oceanography Center has been constantly searching for new ideas for developing and implementing innovative methods and new developments concerning the use of Information Systems in Oceanography, to suit both the Center's monitoring and forecasting products. Within the frame of this scope two major online managing and visualizing data systems have been developed and utilized, those of CYCOFOS and BYTHOS. The Cyprus Coastal Ocean Forecasting and Observing System - CYCOFOS provides a variety of operational predictions such as ultra high, high and medium resolution ocean forecasts in the Levantine Basin, offshore and coastal sea state forecasts in the Mediterranean and Black Sea, tide forecasting in the Mediterranean, ocean remote sensing in the Eastern Mediterranean and coastal and offshore monitoring. As a rich internet application, BYTHOS enables scientists to search, visualize and download oceanographic data online and in real time. The recent improving of BYTHOS system is the extension with access and visualization of CYCOFOS data and overlay forecast fields and observing data. The CYCOFOS data are stored at OPENDAP Server in netCDF format. To search, process and visualize it the php and python scripts were developed. Data visualization is achieved through Mapserver. The BYTHOS forecast access interface allows to search necessary forecasting field by recognizing type, parameter, region, level and time. Also it provides opportunity to overlay different forecast and observing data that can be used for complex analyze of sea basin aspects.

  7. Visualization of Uncertainty

    NASA Astrophysics Data System (ADS)

    Jones, P. W.; Strelitz, R. A.

    2012-12-01

    The output of a simulation is best comprehended through the agency and methods of visualization, but a vital component of good science is knowledge of uncertainty. While great strides have been made in the quantification of uncertainty, especially in simulation, there is still a notable gap: there is no widely accepted means of simultaneously viewing the data and the associated uncertainty in one pane. Visualization saturates the screen, using the full range of color, shadow, opacity and tricks of perspective to display even a single variable. There is no room in the visualization expert's repertoire left for uncertainty. We present a method of visualizing uncertainty without sacrificing the clarity and power of the underlying visualization that works as well in 3-D and time-varying visualizations as it does in 2-D. At its heart, it relies on a principal tenet of continuum mechanics, replacing the notion of value at a point with a more diffuse notion of density as a measure of content in a region. First, the uncertainties calculated or tabulated at each point are transformed into a piecewise continuous field of uncertainty density . We next compute a weighted Voronoi tessellation of a user specified N convex polygonal/polyhedral cells such that each cell contains the same amount of uncertainty as defined by . The problem thus devolves into minimizing . Computation of such a spatial decomposition is O(N*N ), and can be computed iteratively making it possible to update easily over time as well as faster. The polygonal mesh does not interfere with the visualization of the data and can be easily toggled on or off. In this representation, a small cell implies a great concentration of uncertainty, and conversely. The content weighted polygons are identical to the cartogram familiar to the information visualization community in the depiction of things voting results per stat. Furthermore, one can dispense with the mesh or edges entirely to be replaced by symbols or glyphs

  8. Visual short-term memory: activity supporting encoding and maintenance in retinotopic visual cortex.

    PubMed

    Sneve, Markus H; Alnæs, Dag; Endestad, Tor; Greenlee, Mark W; Magnussen, Svein

    2012-10-15

    Recent studies have demonstrated that retinotopic cortex maintains information about visual stimuli during retention intervals. However, the process by which transient stimulus-evoked sensory responses are transformed into enduring memory representations is unknown. Here, using fMRI and short-term visual memory tasks optimized for univariate and multivariate analysis approaches, we report differential involvement of human retinotopic areas during memory encoding of the low-level visual feature orientation. All visual areas show weaker responses when memory encoding processes are interrupted, possibly due to effects in orientation-sensitive primary visual cortex (V1) propagating across extrastriate areas. Furthermore, intermediate areas in both dorsal (V3a/b) and ventral (LO1/2) streams are significantly more active during memory encoding compared with non-memory (active and passive) processing of the same stimulus material. These effects in intermediate visual cortex are also observed during memory encoding of a different stimulus feature (spatial frequency), suggesting that these areas are involved in encoding processes on a higher level of representation. Using pattern-classification techniques to probe the representational content in visual cortex during delay periods, we further demonstrate that simply initiating memory encoding is not sufficient to produce long-lasting memory traces. Rather, active maintenance appears to underlie the observed memory-specific patterns of information in retinotopic cortex.

  9. The impact of expert visual guidance on trainee visual search strategy, visual attention and motor skills.

    PubMed

    Leff, Daniel R; James, David R C; Orihuela-Espina, Felipe; Kwok, Ka-Wai; Sun, Loi Wah; Mylonas, George; Athanasiou, Thanos; Darzi, Ara W; Yang, Guang-Zhong

    2015-01-01

    Minimally invasive and robotic surgery changes the capacity for surgical mentors to guide their trainees with the control customary to open surgery. This neuroergonomic study aims to assess a "Collaborative Gaze Channel" (CGC); which detects trainer gaze-behavior and displays the point of regard to the trainee. A randomized crossover study was conducted in which twenty subjects performed a simulated robotic surgical task necessitating collaboration either with verbal (control condition) or visual guidance with CGC (study condition). Trainee occipito-parietal (O-P) cortical function was assessed with optical topography (OT) and gaze-behavior was evaluated using video-oculography. Performance during gaze-assistance was significantly superior [biopsy number: (mean ± SD): control = 5.6 ± 1.8 vs. CGC = 6.6 ± 2.0; p < 0.05] and was associated with significantly lower O-P cortical activity [ΔHbO2 mMol × cm [median (IQR)] control = 2.5 (12.0) vs. CGC 0.63 (11.2), p < 0.001]. A random effect model (REM) confirmed the association between guidance mode and O-P excitation. Network cost and global efficiency were not significantly influenced by guidance mode. A gaze channel enhances performance, modulates visual search, and alleviates the burden in brain centers subserving visual attention and does not induce changes in the trainee's O-P functional network observable with the current OT technique. The results imply that through visual guidance, attentional resources may be liberated, potentially improving the capability of trainees to attend to other safety critical events during the procedure.

  10. The impact of expert visual guidance on trainee visual search strategy, visual attention and motor skills

    PubMed Central

    Leff, Daniel R.; James, David R. C.; Orihuela-Espina, Felipe; Kwok, Ka-Wai; Sun, Loi Wah; Mylonas, George; Athanasiou, Thanos; Darzi, Ara W.; Yang, Guang-Zhong

    2015-01-01

    Minimally invasive and robotic surgery changes the capacity for surgical mentors to guide their trainees with the control customary to open surgery. This neuroergonomic study aims to assess a “Collaborative Gaze Channel” (CGC); which detects trainer gaze-behavior and displays the point of regard to the trainee. A randomized crossover study was conducted in which twenty subjects performed a simulated robotic surgical task necessitating collaboration either with verbal (control condition) or visual guidance with CGC (study condition). Trainee occipito-parietal (O-P) cortical function was assessed with optical topography (OT) and gaze-behavior was evaluated using video-oculography. Performance during gaze-assistance was significantly superior [biopsy number: (mean ± SD): control = 5.6 ± 1.8 vs. CGC = 6.6 ± 2.0; p < 0.05] and was associated with significantly lower O-P cortical activity [ΔHbO2 mMol × cm [median (IQR)] control = 2.5 (12.0) vs. CGC 0.63 (11.2), p < 0.001]. A random effect model (REM) confirmed the association between guidance mode and O-P excitation. Network cost and global efficiency were not significantly influenced by guidance mode. A gaze channel enhances performance, modulates visual search, and alleviates the burden in brain centers subserving visual attention and does not induce changes in the trainee’s O-P functional network observable with the current OT technique. The results imply that through visual guidance, attentional resources may be liberated, potentially improving the capability of trainees to attend to other safety critical events during the procedure. PMID:26528160

  11. Spatial Visualization in Introductory Geology Courses

    NASA Astrophysics Data System (ADS)

    Reynolds, S. J.

    2004-12-01

    Visualization is critical to solving most geologic problems, which involve events and processes across a broad range of space and time. Accordingly, spatial visualization is an essential part of undergraduate geology courses. In such courses, students learn to visualize three-dimensional topography from two-dimensional contour maps, to observe landscapes and extract clues about how that landscape formed, and to imagine the three-dimensional geometries of geologic structures and how these are expressed on the Earth's surface or on geologic maps. From such data, students reconstruct the geologic history of areas, trying to visualize the sequence of ancient events that formed a landscape. To understand the role of visualization in student learning, we developed numerous interactive QuickTime Virtual Reality animations to teach students the most important visualization skills and approaches. For topography, students can spin and tilt contour-draped, shaded-relief terrains, flood virtual landscapes with water, and slice into terrains to understand profiles. To explore 3D geometries of geologic structures, they interact with virtual blocks that can be spun, sliced into, faulted, and made partially transparent to reveal internal structures. They can tilt planes to see how they interact with topography, and spin and tilt geologic maps draped over digital topography. The GeoWall system allows students to see some of these materials in true stereo. We used various assessments to research the effectiveness of these materials and to document visualization strategies students use. Our research indicates that, compared to control groups, students using such materials improve more in their geologic visualization abilities and in their general visualization abilities as measured by a standard spatial visualization test. Also, females achieve greater gains, improving their general visualization abilities to the same level as males. Misconceptions that students carry obstruct

  12. Are flash-evoked visual potentials useful for intraoperative monitoring of visual pathway function?

    PubMed

    Cedzich, C; Schramm, J; Fahlbusch, R

    1987-11-01

    Flash-evoked visual potentials (VEPs) recorded from the scalp were used in a series of 35 patients with tumors along the visual pathway: 3 orbital tumors, 25 perisellar tumors, 4 intraventricular tumors, and 3 occipital lesions. Preoperatively, various combinations of impaired visual fields and visual acuity were observed in over 90% of the patients. A postoperative decrease in visual function was observed in 3 cases. Of the 25 perisellar lesions, 13 were operated through a standard frontotemporal craniotomy and 12 were operated through a transnasal-transsphenoidal approach. VEPs were highly susceptible to volatile anesthetics, and there was a significant incidence of spontaneous latency increases and amplitude decreases in a large number of patients. There was an unacceptably high number of cases with significant VEP alteration occurring without concomitant visual function change. During trepanation or the transnasal approach, a reversible potential loss was observed in 11 patients, a profoundly altered wave form was seen in 8 cases, and a loss of single peaks was observed in 15 patients. During dissection of the tumor, a reversible potential loss or a potential with unidentifiable peaks was found in 25 cases; however, the VEPs recovered during closure or in the recovery room. There was no correlation between intraoperative VEP changes and the postoperative changes in visual function. In only 1 patient with an insignificant postoperative decrease in visual acuity from 0.4 to 0.3 was there a concomitant intraoperative potential loss. The major conclusion of our findings is that light-emitting diode flash-evoked VEPs demonstrate intraoperative changes that appear too early and too prominently to be caused solely by manipulation of the optic pathways.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Perception and Attention for Visualization

    ERIC Educational Resources Information Center

    Haroz, Steve

    2013-01-01

    This work examines how a better understanding of visual perception and attention can impact visualization design. In a collection of studies, I explore how different levels of the visual system can measurably affect a variety of visualization metrics. The results show that expert preference, user performance, and even computational performance are…

  14. The Levels of Visual Framing

    ERIC Educational Resources Information Center

    Rodriguez, Lulu; Dimitrova, Daniela V.

    2011-01-01

    While framing research has centered mostly on the evaluations of media texts, visual news discourse has remained relatively unexamined. This study surveys the visual framing techniques and methods employed in previous studies and proposes a four-tiered model of identifying and analyzing visual frames: (1) visuals as denotative systems, (2) visuals…

  15. The Elephants of Visual Literacy.

    ERIC Educational Resources Information Center

    Barley, Steven D., Ed.; Ball, Richard R., Ed.

    Visual literacy, as used here, refers to the skills which let a person understand and use visuals to communicate his messages and interpret the messages of others. Visual literacy should be important in the curriculum because: 1) children pay more attention to movies and television than they do to teachers; 2) the plethora of visual information…

  16. The Development of Visual Areas Depends Differently on Visual Experience

    PubMed Central

    Jiang, Tianzi; Yu, Chunshui

    2013-01-01

    Visual experience plays an important role in the development of the visual cortex; however, recent functional imaging studies have shown that the functional organization is preserved in several higher-tier visual areas in congenitally blind subjects, indicating that maturation of visual areas depend unequally on visual experience. In this study, we aim to validate this hypothesis using a multimodality MRI approach. We found increased cortical thickness in the congenitally blind was present in the early visual areas and absent in the higher-tier ones, suggesting that the structural development of the visual cortex depends hierarchically on visual experience. In congenitally blind subjects, the decreased resting-state functional connectivity with the primary somatosensory cortex was more prominent in the early visual areas than in the higher-tier ones and were more pronounced in the ventral stream than in the dorsal one, suggesting that the development of functional organization of the visual cortex also depends differently on visual experience. Moreover, congenitally blind subjects showed normal or increased functional connectivity between ipsilateral higher-tier and early visual areas, suggesting an indirect corticocortical pathway through which somatosenroy information can reach the early visual areas. These findings support our hypothesis that the development of visual areas depends differently on visual experience. PMID:23308283

  17. Visualizing conserved gene location across microbe genomes

    NASA Astrophysics Data System (ADS)

    Shaw, Chris D.

    2009-01-01

    This paper introduces an analysis-based zoomable visualization technique for displaying the location of genes across many related species of microbes. The purpose of this visualizatiuon is to enable a biologist to examine the layout of genes in the organism of interest with respect to the gene organization of related organisms. During the genomic annotation process, the ability to observe gene organization in common with previously annotated genomes can help a biologist better confirm the structure and function of newly analyzed microbe DNA sequences. We have developed a visualization and analysis tool that enables the biologist to observe and examine gene organization among genomes, in the context of the primary sequence of interest. This paper describes the visualization and analysis steps, and presents a case study using a number of Rickettsia genomes.

  18. Visual determination of differential renal function

    SciTech Connect

    Kipper, M.S.; Witztum, K.F.; Taylor, A. Jr.

    1986-05-01

    Forty patients (43 studies) referred for determination of differential renal function were imaged 24 hours after intravenous administration of Tc-99m-2, 3 DMSA. Visual assessment of relative renal uptake was estimated independently by three observers at three different hospitals from analog images on standard x-ray film. The results were compared with the relative DMSA uptake obtained by summing counts in computer-assisted regions of interest placed over each kidney. There was excellent correlation between the visual estimates of each observer and the computer-generated values (r = 0.98, 0.96, and 0.98, respectively). If a computer is not available, good visual estimates of differential uptake still may be obtained when static imaging agents such as DMSA are administered.

  19. Learning Science Through Visualization

    NASA Technical Reports Server (NTRS)

    Chaudhury, S. Raj

    2005-01-01

    In the context of an introductory physical science course for non-science majors, I have been trying to understand how scientific visualizations of natural phenomena can constructively impact student learning. I have also necessarily been concerned with the instructional and assessment approaches that need to be considered when focusing on learning science through visually rich information sources. The overall project can be broken down into three distinct segments : (i) comparing students' abilities to demonstrate proportional reasoning competency on visual and verbal tasks (ii) decoding and deconstructing visualizations of an object falling under gravity (iii) the role of directed instruction to elicit alternate, valid scientific visualizations of the structure of the solar system. Evidence of student learning was collected in multiple forms for this project - quantitative analysis of student performance on written, graded assessments (tests and quizzes); qualitative analysis of videos of student 'think aloud' sessions. The results indicate that there are significant barriers for non-science majors to succeed in mastering the content of science courses, but with informed approaches to instruction and assessment, these barriers can be overcome.

  20. Camouflage and visual perception

    PubMed Central

    Troscianko, Tom; Benton, Christopher P.; Lovell, P. George; Tolhurst, David J.; Pizlo, Zygmunt

    2008-01-01

    How does an animal conceal itself from visual detection by other animals? This review paper seeks to identify general principles that may apply in this broad area. It considers mechanisms of visual encoding, of grouping and object encoding, and of search. In most cases, the evidence base comes from studies of humans or species whose vision approximates to that of humans. The effort is hampered by a relatively sparse literature on visual function in natural environments and with complex foraging tasks. However, some general constraints emerge as being potentially powerful principles in understanding concealment—a ‘constraint’ here means a set of simplifying assumptions. Strategies that disrupt the unambiguous encoding of discontinuities of intensity (edges), and of other key visual attributes, such as motion, are key here. Similar strategies may also defeat grouping and object-encoding mechanisms. Finally, the paper considers how we may understand the processes of search for complex targets in complex scenes. The aim is to provide a number of pointers towards issues, which may be of assistance in understanding camouflage and concealment, particularly with reference to how visual systems can detect the shape of complex, concealed objects. PMID:18990671

  1. Visual surveillance in craniosynostoses.

    PubMed

    Nischal, Ken K

    2014-01-01

    Craniosynostosis is the premature fusion of one or more cranial sutures that may be isolated or syndromic. These children can have multiple developmental issues including speech, hearing, and vision, in addition to the aesthetic issue of an abnormally shaped skull and midfacial hypoplasia. As the aesthetic outcomes of craniofacial surgery have improved, attention has turned on the functional outcomes and visual loss is a well-known problem with these patients. In the past 15 years, a greater understanding of the causes of visual loss has developed. Factors such as amblyopia, corneal exposure, and optic neuropathy are all now looked for to prevent or reduce visual loss. Optic neuropathy is caused by craniocerebral disproportion (though to a lesser extent than originally thought), cerebral hypo perfusion, hydrocephalus, and obstructive sleep apnea. Amblyopia is due to increased incidence of strabismus, anisometropia, astigmatism, and ametropia in these cases. A comprehensive approach to managing these children's visual function allows the clinician to reduce potential visual loss in children with craniosynostoses especially the syndromic variety. PMID:25313108

  2. Frameless Volume Visualization.

    PubMed

    Petkov, Kaloian; Kaufman, Arie E

    2016-02-01

    We have developed a novel visualization system based on the reconstruction of high resolution and high frame rate images from a multi-tiered stream of samples that are rendered framelessly. This decoupling of the rendering system from the display system is particularly suitable when dealing with very high resolution displays or expensive rendering algorithms, where the latency of generating complete frames may be prohibitively high for interactive applications. In contrast to the traditional frameless rendering technique, we generate the lowest latency samples on the optimal sampling lattice in the 3D domain. This approach avoids many of the artifacts associated with existing sample caching and reprojection methods during interaction that may not be acceptable in many visualization applications. Advanced visualization effects are generated remotely and streamed into the reconstruction system using tiered samples with varying latencies and quality levels. We demonstrate the use of our visualization system for the exploration of volumetric data at stable guaranteed frame rates on high resolution displays, including a 470 megapixel tiled display as part of the Reality Deck immersive visualization facility.

  3. Atypical visual processing in posttraumatic stress disorder☆

    PubMed Central

    Mueller-Pfeiffer, Christoph; Schick, Matthis; Schulte-Vels, Thomas; O'Gorman, Ruth; Michels, Lars; Martin-Soelch, Chantal; Blair, James R.; Rufer, Michael; Schnyder, Ulrich; Zeffiro, Thomas; Hasler, Gregor

    2013-01-01

    Background Many patients with Posttraumatic Stress Disorder (PTSD) feel overwhelmed in situations with high levels of sensory input, as in crowded situations with complex sensory characteristics. These difficulties might be related to subtle sensory processing deficits similar to those that have been found for sounds in electrophysiological studies. Method Visual processing was investigated with functional magnetic resonance imaging in trauma-exposed participants with (N = 18) and without PTSD (N = 21) employing a picture-viewing task. Results Activity observed in response to visual scenes was lower in PTSD participants 1) in the ventral stream of the visual system, including striate and extrastriate, inferior temporal, and entorhinal cortices, and 2) in dorsal and ventral attention systems (P < 0.05, FWE-corrected). These effects could not be explained by the emotional salience of the pictures. Conclusions Visual processing was substantially altered in PTSD in the ventral visual stream, a component of the visual system thought to be responsible for object property processing. Together with previous reports of subtle auditory deficits in PTSD, these findings provide strong support for potentially important sensory processing deficits, whose origins may be related to dysfunctional attention processes. PMID:24371791

  4. Visually guided collision avoidance and collision achievement.

    PubMed

    Regan; Gray

    2000-03-01

    To survive on today's highways, a driver must have highly developed skills in visually guided collision avoidance. To play such games as cricket, tennis or baseball demands accurate, precise and reliable collision achievement. This review discusses evidence that some of these tasks are performed by predicting where an object will be at some sharply defined instant, several hundred milliseconds in the future, while other tasks are performed by utilizing the fact that some of our motor actions change what we see in ways that obey lawful relationships, and can therefore be learned. Several monocular and binocular visual correlates of the direction of an object's motion relative to the observer's head have been derived theoretically, along with visual correlates of the time to collision with an approaching object. Although laboratory psychophysics can identify putative neural mechanisms by showing which of the known correlates are processed by the human visual system independently of other visual information, it is only field research on, for example, driving, aviation and sport that can show which visual cues are actually used in these activities. This article reviews this research and describes a general psychophysically based rational approach to the design of such field studies.

  5. Visual characteristics of clay target shooters.

    PubMed

    Abernethy, B; Neal, R J

    1999-03-01

    A comprehensive battery of standardised visual tests was administered to 11 skilled and 12 novice clay target shooters in an attempt to determine the distinctive visual characteristics of expert performers in this sport. The static and dynamic visual acuity, ocular muscle balance, ocular dominance, depth perception and colour vision of each of the subjects was measured in addition to their performance on simple and choice reaction time, peripheral response time, rapid tachistoscopic detection, coincidence timing and eye movement skills tasks. Expert superiority was observed on the simple reaction time measure only, and the novices actually outperformed the skilled subjects on a number of the other visual measures (viz., static acuity at near distance, dynamic acuity, vertical ocular muscle balance, choice reaction time and rapid target detection discriminability). Scores on all measures for both groups were within the expected normal range indicating that normal and not necessarily above-average basic visual functioning is sufficient to support skilled clay target shooting. An important implication of the finding that skilled shooters are not characterised by supranormal levels of basic visual functioning is the recognition that any attempt to improve shooting performance through training of general attributes of vision to supranormal levels is likely to be unproductive.

  6. The pattern of visual deficits in amblyopia.

    PubMed

    McKee, Suzanne P; Levi, Dennis M; Movshon, J Anthony

    2003-01-01

    Amblyopia is usually defined as a deficit in optotype (Snellen) acuity with no detectable organic cause. We asked whether this visual abnormality is completely characterized by the deficit in optotype acuity, or whether it has distinct forms that are determined by the conditions associated with the acuity loss, such as strabismus or anisometropia. To decide this issue, we measured optotype acuity, Vernier acuity, grating acuity, contrast sensitivity, and binocular function in 427 adults with amblyopia or with risk factors for amblyopia and in a comparison group of 68 normal observers. Optotype acuity accounts for much of the variance in Vernier and grating acuity, and somewhat less of the variance in contrast sensitivity. Nevertheless, there are differences in the patterns of visual loss among the clinically defined categories, particularly between strabismic and anisometropic categories. We used factor analysis to create a succinct representation of our measurement space. This analysis revealed two main dimensions of variation in the visual performance of our abnormal sample, one related to the visual acuity measures (optotype, Vernier, and grating acuity) and the other related to the contrast sensitivity measures (Pelli-Robson and edge contrast sensitivity). Representing our data in this space reveals distinctive distributions of visual loss for different patient categories, and suggests that two consequences of the associated conditions--reduced resolution and loss of binocularity--determine the pattern of visual deficit. Non-binocular observers with mild-to-moderate acuity deficits have, on average, better monocular contrast sensitivity than do binocular observers with the same acuity loss. Despite their superior contrast sensitivity, non-binocular observers typically have poorer optotype acuity and Vernier acuity, at a given level of grating acuity, than those with residual binocular function. PMID:12875634

  7. Data Visualization in Sociology

    PubMed Central

    Healy, Kieran; Moody, James

    2014-01-01

    Visualizing data is central to social scientific work. Despite a promising early beginning, sociology has lagged in the use of visual tools. We review the history and current state of visualization in sociology. Using examples throughout, we discuss recent developments in ways of seeing raw data and presenting the results of statistical modeling. We make a general distinction between those methods and tools designed to help explore datasets, and those designed to help present results to others. We argue that recent advances should be seen as part of a broader shift towards easier sharing of the code and data both between researchers and with wider publics, and encourage practitioners and publishers to work toward a higher and more consistent standard for the graphical display of sociological insights. PMID:25342872

  8. Multimodal brain visualization

    NASA Astrophysics Data System (ADS)

    Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Current connectivity diagrams of human brain image data are either overly complex or overly simplistic. In this work we introduce simple yet accurate interactive visual representations of multiple brain image structures and the connectivity among them. We map cortical surfaces extracted from human brain magnetic resonance imaging (MRI) data onto 2D surfaces that preserve shape (angle), extent (area), and spatial (neighborhood) information for 2D (circular disk) and 3D (spherical) mapping, split these surfaces into separate patches, and cluster functional and diffusion tractography MRI connections between pairs of these patches. The resulting visualizations are easier to compute on and more visually intuitive to interact with than the original data, and facilitate simultaneous exploration of multiple data sets, modalities, and statistical maps.

  9. Deafness and visual enumeration

    PubMed Central

    Hauser, Peter C.; Dye, Matthew W. G.; Boutla, Mrim; Green, C. Shawn; Bavelier, Daphne

    2007-01-01

    Previous studies have demonstrated that early deafness causes enhancements in peripheral visual attention. Here, we ask if this cross-modal plasticity of visual attention is accompanied by an increase in the number of objects that can be grasped at once. In a first experiment using an enumeration task, Deaf adult native signers and hearing non-signers performed comparably, suggesting that deafness does not enhance the number of objects one can attend to simultaneously. In a second experiment using the Multiple Object Task, Deaf adult native signers and hearing non-signers also performed comparably when required to monitor several, distinct, moving targets among moving distractors. The results of these experiments suggest that deafness does not significantly alter the ability to allocate attention to several objects at once. Thus, early deafness does not enhance all facets of visual attention, but rather its effects are quite specific. SECTION: Cognitive and Behavioral Neuroscience PMID:17467671

  10. Fear selectively modulates visual mental imagery and visual perception.

    PubMed

    Borst, Grégoire; Kosslyn, Stephen M

    2010-05-01

    Emotions have been shown to modulate low-level visual processing of simple stimuli. In this study, we investigate whether emotions only modulate processing of visual representations created from direct visual inputs or whether they also modulate representations that underlie visual mental images. Our results demonstrate that when participants visualize or look at the global shape of written words (low-spatial-frequency visual information), the prior brief presentation of fearful faces enhances processing, whereas when participants visualize or look at details of written words (high-spatial-frequency visual information), the prior brief presentation of fearful faces impairs processing. This study demonstrates that emotions have similar effects on low-level processing of visual percepts and of internal representations created on the basis of information stored in long-term memory. PMID:20182955

  11. Netgram: Visualizing Communities in Evolving Networks.

    PubMed

    Mall, Raghvendra; Langone, Rocco; Suykens, Johan A K

    2015-01-01

    Real-world complex networks are dynamic in nature and change over time. The change is usually observed in the interactions within the network over time. Complex networks exhibit community like structures. A key feature of the dynamics of complex networks is the evolution of communities over time. Several methods have been proposed to detect and track the evolution of these groups over time. However, there is no generic tool which visualizes all the aspects of group evolution in dynamic networks including birth, death, splitting, merging, expansion, shrinkage and continuation of groups. In this paper, we propose Netgram: a tool for visualizing evolution of communities in time-evolving graphs. Netgram maintains evolution of communities over 2 consecutive time-stamps in tables which are used to create a query database using the sql outer-join operation. It uses a line-based visualization technique which adheres to certain design principles and aesthetic guidelines. Netgram uses a greedy solution to order the initial community information provided by the evolutionary clustering technique such that we have fewer line cross-overs in the visualization. This makes it easier to track the progress of individual communities in time evolving graphs. Netgram is a generic toolkit which can be used with any evolutionary community detection algorithm as illustrated in our experiments. We use Netgram for visualization of topic evolution in the NIPS conference over a period of 11 years and observe the emergence and merging of several disciplines in the field of information processing systems. PMID:26356538

  12. Surface visualization of electromagnetic brain activity.

    PubMed

    Badea, Alexandra; Kostopoulos, George K; Ioannides, Andreas A

    2003-08-15

    Advances in hardware and software have made possible the reconstruction of brain activity from non-invasive electrophysiological measurements over a large part of the brain. The appreciation of the information content in the data is enhanced when relevant anatomical detail is also available for visualization. Different neuroscientific questions give rise to different requirements for optimal superposition of structure and function. Most available software deal with scalar measures of activity, especially hemodynamic changes. In contrast, the electrophysiological observables are generated by electrical activity, which depends on the synchrony of neuronal assemblies and the geometry of the local cortical surface. We describe methods for segmentation and visualization of spatio-temporal brain activity, which allow the interplay of geometry and scalar as well as vector properties of the current density directly in the representations. The utility of these methods is demonstrated through displays of tomographic reconstructions of early sensory processing in the somatosensory and visual modality extracted from magnetoencephalography (MEG) data. The activation course characteristic to a specific area could be observed as current density or statistical maps independently and/or contrasted to the activity in other areas or the whole brain. MEG and functional magnetic resonance imaging (fMRI) activations were simultaneously visualized. Integrating and visualizing complementary functional data into a single environment helps evaluating analysis and understanding structure/function relationships in normal and diseased brain.

  13. Skylab observations of Comet Kohoutek

    NASA Technical Reports Server (NTRS)

    Snoddy, W. C.; Gary, G. A.

    1974-01-01

    This paper summarizes the special operational procedures developed to observe the Comet Kohoutek from Skylab and the scientific results from these observations. Emphasis is placed on results from Skylab experiments S052, White Light Coronagraph; S201, Far UV Electronographic Camera; S233, Kohoutek Photometric Photography; S019, UV Stellar Astronomy; S183, Ultraviolet Panorama Telescope; and S082B, Ultraviolet Spectrography. Visual observations by the astronaut crew and the significance of these observations are discussed.

  14. CMS tracker visualization tools

    NASA Astrophysics Data System (ADS)

    Mennea, M. S.; Osborne, I.; Regano, A.; Zito, G.

    2005-08-01

    This document will review the design considerations, implementations and performance of the CMS Tracker Visualization tools. In view of the great complexity of this sub-detector (more than 50 millions channels organized in 16540 modules each one of these being a complete detector), the standard CMS visualization tools (IGUANA and IGUANACMS) that provide basic 3D capabilities and integration within CMS framework, respectively, have been complemented with additional 2D graphics objects. Based on the experience acquired using this software to debug and understand both hardware and software during the construction phase, we propose possible future improvements to cope with online monitoring and event analysis during data taking.

  15. Visual Inference Programming

    NASA Technical Reports Server (NTRS)

    Wheeler, Kevin; Timucin, Dogan; Rabbette, Maura; Curry, Charles; Allan, Mark; Lvov, Nikolay; Clanton, Sam; Pilewskie, Peter

    2002-01-01

    The goal of visual inference programming is to develop a software framework data analysis and to provide machine learning algorithms for inter-active data exploration and visualization. The topics include: 1) Intelligent Data Understanding (IDU) framework; 2) Challenge problems; 3) What's new here; 4) Framework features; 5) Wiring diagram; 6) Generated script; 7) Results of script; 8) Initial algorithms; 9) Independent Component Analysis for instrument diagnosis; 10) Output sensory mapping virtual joystick; 11) Output sensory mapping typing; 12) Closed-loop feedback mu-rhythm control; 13) Closed-loop training; 14) Data sources; and 15) Algorithms. This paper is in viewgraph form.

  16. USGS Scientific Visualization Laboratory

    USGS Publications Warehouse

    ,

    1995-01-01

    The U.S. Geological Survey's (USGS) Scientific Visualization Laboratory at the National Center in Reston, Va., provides a central facility where USGS employees can use state-of-the-art equipment for projects ranging from presentation graphics preparation to complex visual representations of scientific data. Equipment including color printers, black-and-white and color scanners, film recorders, video equipment, and DOS, Apple Macintosh, and UNIX platforms with software are available for both technical and nontechnical users. The laboratory staff provides assistance and demonstrations in the use of the hardware and software products.

  17. Multielement Visual Tracking: Attention and Perceptual Organization.

    ERIC Educational Resources Information Center

    Yantis, Steven

    1992-01-01

    Presents 7 experiments with 118 undergraduates tracking multiple randomly moving visual elements under various conditions. Observers spontaneously grouped the target elements and directed attention toward this coherent nonrigid virtual object. Results support object-based theories of attention and show that perceptual grouping, a purely…

  18. Visual Thinking Strategies = Creative and Critical Thinking

    ERIC Educational Resources Information Center

    Moeller, Mary; Cutler, Kay; Fiedler, Dave; Weier, Lisa

    2013-01-01

    Implementation of Visual Thinking Strategies (VTS) into the Camelot Intermediate School curriculum in Brookings, South Dakota, has fostered the development of creative and critical thinking skills in 4th- and 5th-grade students. Making meaning together by observing carefully, deciphering patterns, speculating, clarifying, supporting opinions, and…

  19. Visual speech gestures modulate efferent auditory system.

    PubMed

    Namasivayam, Aravind Kumar; Wong, Wing Yiu Stephanie; Sharma, Dinaay; van Lieshout, Pascal

    2015-03-01

    Visual and auditory systems interact at both cortical and subcortical levels. Studies suggest a highly context-specific cross-modal modulation of the auditory system by the visual system. The present study builds on this work by sampling data from 17 young healthy adults to test whether visual speech stimuli evoke different responses in the auditory efferent system compared to visual non-speech stimuli. The descending cortical influences on medial olivocochlear (MOC) activity were indirectly assessed by examining the effects of contralateral suppression of transient-evoked otoacoustic emissions (TEOAEs) at 1, 2, 3 and 4 kHz under three conditions: (a) in the absence of any contralateral noise (Baseline), (b) contralateral noise + observing facial speech gestures related to productions of vowels /a/ and /u/ and (c) contralateral noise + observing facial non-speech gestures related to smiling and frowning. The results are based on 7 individuals whose data met strict recording criteria and indicated a significant difference in TEOAE suppression between observing speech gestures relative to the non-speech gestures, but only at the 1 kHz frequency. These results suggest that observing a speech gesture compared to a non-speech gesture may trigger a difference in MOC activity, possibly to enhance peripheral neural encoding. If such findings can be reproduced in future research, sensory perception models and theories positing the downstream convergence of unisensory streams of information in the cortex may need to be revised.

  20. Wordless Books: An Approach to Visual Literacy.

    ERIC Educational Resources Information Center

    Lindauer, Shelley L. Knudsen

    1988-01-01

    Argues that wordless books allow prereading children to create their own stories, enhance vocabulary acquisition, help children develop "top to bottom" and "right to left" concepts, and promote observation, sequential, visual, and inferential thinking. Describes several ways to use wordless books. Includes bibliography of 36 wordless books. (SR)

  1. A Boolean Map Theory of Visual Attention

    ERIC Educational Resources Information Center

    Huang, Liqiang; Pashler, Harold

    2007-01-01

    A theory is presented that attempts to answer two questions. What visual contents can an observer consciously access at one moment? Answer: only one feature value (e.g., green) per dimension, but those feature values can be associated (as a group) with multiple spatially precise locations (comprising a single labeled Boolean map). How can an…

  2. Visual Data Exploration and Analysis - Report on the Visualization Breakout Session of the SCaLeS Workshop

    SciTech Connect

    Bethel, E. Wes; Frank, Randy; Fulcomer, Sam; Hansen, Chuck; Joy, Ken; Kohl, Jim; Middleton, Don

    2003-07-14

    Scientific visualization is the transformation of abstract information into images, and it plays an integral role in the scientific process by facilitating insight into observed or simulated phenomena. Visualization as a discipline spans many research areas from computer science, cognitive psychology and even art. Yet the most successful visualization applications are created when close synergistic interactions with domain scientists are part of the algorithmic design and implementation process, leading to visual representations with clear scientific meaning. Visualization is used to explore, to debug, to gain understanding, and as an analysis tool. Visualization is literally everywhere--images are present in this report, on television, on the web, in books and magazines--the common theme is the ability to present information visually that is rapidly assimilated by human observers, and transformed into understanding or insight. As an indispensable part a modern science laboratory, visualization is akin to the biologist's microscope or the electrical engineer's oscilloscope. Whereas the microscope is limited to small specimens or use of optics to focus light, the power of scientific visualization is virtually limitless: visualization provides the means to examine data that can be at galactic or atomic scales, or at any size in between. Unlike the traditional scientific tools for visual inspection, visualization offers the means to ''see the unseeable.'' Trends in demographics or changes in levels of atmospheric CO{sub 2} as a function of greenhouse gas emissions are familiar examples of such unseeable phenomena. Over time, visualization techniques evolve in response to scientific need. Each scientific discipline has its ''own language,'' verbal and visual, used for communication. The visual language for depicting electrical circuits is much different than the visual language for depicting theoretical molecules or trends in the stock market. There is no ''one

  3. Filling the Astronomical Void - A Visual Medium for a Visual Subject

    NASA Astrophysics Data System (ADS)

    Ryan, J.

    1996-12-01

    Astronomy is fundamentally a visual subject. The modern science of astronomy has at its foundation the ancient art of observing the sky visually. The visual elements of astronomy are arguably the most important. Every person in the entire world is affected by visually-observed astronomical phenomena such as the seasonal variations in daylight. However, misconceptions abound and the average person cannot recognize the simple signs in the sky that point to the direction, the hour and the season. Educators and astronomy popularizers widely lament that astronomy is not appreciated in our society. Yet, there is a remarkable dearth of popular literature for teaching the visual elements of astronomy. This is what I refer to as *the astronomical void.* Typical works use illustrations sparsely, relying most heavily on text-based descriptions of the visual astronomical phenomena. Such works leave significant inferential gaps to the inexperienced reader, who is unequipped for making astronomical observations. Thus, the astronomical void remains unfilled by much of the currently available literature. I therefore propose the introduction of a visually-oriented medium for teaching the visual elements of Astronomy. To this end, I have prepared a series of astronomy "comic strips" that are intended to fill the astronomical void. By giving the illustrations the central place, the comic strip medium permits the depiction of motion and other sequential activity, thus effectively representing astronomical phenomena. In addition to the practical advantages, the comic strip is a "user friendly" medium that is inviting and entertaining to a reader. At the present time, I am distributing a monthly comic strip entitled *Starman*, which appears in the newsletters of over 120 local astronomy organizations and on the web at http://www.cyberdrive.net/ starman. I hope to eventually publish a series of full-length books and believe that astronomical comic strips will help expand the perimeter of

  4. Frida Kahlo: Visual Articulations of Suffering and Loss.

    ERIC Educational Resources Information Center

    Nixon, Lois LaCivita

    1996-01-01

    Illustrates the value of interdisciplinary approaches to patient care by exploring visual articulations of suffering as rendered by one artist. Makes general observations about the nature of humanities courses offered to medical students and depicts a visual portrayal of an illness story representing personal perspectives about patient suffering…

  5. Visual Medium in the Service and Disservice of Education

    ERIC Educational Resources Information Center

    Wong, Wan-chi

    2001-01-01

    There are different ways of exploring and examining the visual medium in the service and disservice of education. A discursive form rather than a visual medium is chosen in this attempt. Utilizing the conceptualizations of Suzanne Langer, Christine Nystrom observed that American symbolic environments have undergone a massive shift from discursive…

  6. FMRI of visual working memory in high school football players.

    PubMed

    Shenk, Trey E; Robinson, Meghan E; Svaldi, Diana O; Abbas, Kausar; Breedlove, Katherine M; Leverenz, Larry J; Nauman, Eric A; Talavage, Thomas M

    2015-01-01

    Visual working memory deficits have been observed in at-risk athletes. This study uses a visual N-back working memory functional magnetic resonance imaging task to longitudinally assess asymptomatic football athletes for abnormal activity. Athletes were increasingly "flagged" as the season progressed. Flagging may provide early detection of injury. PMID:25961587

  7. Working Memory Enhances Visual Perception: Evidence from Signal Detection Analysis

    ERIC Educational Resources Information Center

    Soto, David; Wriglesworth, Alice; Bahrami-Balani, Alex; Humphreys, Glyn W.

    2010-01-01

    We show that perceptual sensitivity to visual stimuli can be modulated by matches between the contents of working memory (WM) and stimuli in the visual field. Observers were presented with an object cue (to hold in WM or to merely attend) and subsequently had to identify a brief target presented within a colored shape. The cue could be…

  8. Testing of visual field with virtual reality goggles in manual and visual grasp modes.

    PubMed

    Wroblewski, Dariusz; Francis, Brian A; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

    2014-01-01

    Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4-6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode.

  9. Effect of static visual acuity on dynamic visual acuity: a pilot study.

    PubMed

    Nakatsuka, Mieko; Ueda, Tetsuo; Nawa, Yoshiaki; Yukawa, Eiichi; Hara, Tokuko; Hara, Yoshiaki

    2006-08-01

    The aim of this pilot study was to evaluate whether dynamic visual acuity changes with or without refractive correction. 42 healthy enrolled subjects with normal vision were divided into two age-matched groups. In Group A, dynamic visual acuity was measured first with the refractive error fully corrected and then without. In Group B, dynamic visual acuity measurements were taken in the reverse order of that performed by Group A. The measurements were binocularly performed five times using free-head viewing after dynamic visual acuity values were stable. Significant changes in dynamic visual acuity (static visual acuity 20/20 vs 12/20) were observed in both Group A (171.6 +/- 36.0 deg./sec. vs 151.8 +/- 39.6 deg./sec., Wilcoxon test, p < .001) and Group B (169.8 +/- 30.0 deg./sec. vs 151.2 +/- 36.0 deg./sec., Wilcoxon test, p < .001). The interaction was significant (F1.20 = 8.12, p = .009). These results indicated that refractive correction affected dynamic visual acuity.

  10. Visualizing Humans by Computer.

    ERIC Educational Resources Information Center

    Magnenat-Thalmann, Nadia

    1992-01-01

    Presents an overview of the problems and techniques involved in visualizing humans in a three-dimensional scene. Topics discussed include human shape modeling, including shape creation and deformation; human motion control, including facial animation and interaction with synthetic actors; and human rendering and clothing, including textures and…

  11. Aging and Visual Impairment.

    ERIC Educational Resources Information Center

    Morse, A. R.; And Others

    1987-01-01

    Eye diseases of the aged include diabetic retinopathy, senile cataracts, senile macular degeneration, and glaucoma. Environmental modifications such as better levels of illumination and reduction of glare can enhance an individual's ability to function. Programs to screen and treat visual problems in elderly persons are called for. (Author/JDD)

  12. Curriculum: Managed Visual Reality.

    ERIC Educational Resources Information Center

    Gueulette, David G.

    This paper explores the association between the symbolized and the actualized, beginning with the prehistoric notion of a "reality double," in which no practical difference exists between pictorial representations, visual symbols, and real-life events and situations. Alchemists of the Middle Ages, with their paradoxical vision of the universe…

  13. Visualizing Dispersion Interactions

    ERIC Educational Resources Information Center

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  14. The Visual Identity Project

    ERIC Educational Resources Information Center

    Tennant-Gadd, Laurie; Sansone, Kristina Lamour

    2008-01-01

    Identity is the focus of the middle-school visual arts program at Cambridge Friends School (CFS) in Cambridge, Massachusetts. Sixth graders enter the middle school and design a personal logo as their first major project in the art studio. The logo becomes a way for students to introduce themselves to their teachers and to represent who they are…

  15. Thinking Visually about Algebra

    ERIC Educational Resources Information Center

    Baroudi, Ziad

    2015-01-01

    Many introductions to algebra in high school begin with teaching students to generalise linear numerical patterns. This article argues that this approach needs to be changed so that students encounter variables in the context of modelling visual patterns so that the variables have a meaning. The article presents sample classroom activities,…

  16. Robotic Intelligence Kernel: Visualization

    SciTech Connect

    2009-09-16

    The INL Robotic Intelligence Kernel-Visualization is the software that supports the user interface. It uses the RIK-C software to communicate information to and from the robot. The RIK-V illustrates the data in a 3D display and provides an operating picture wherein the user can task the robot.

  17. Visual Screening: A Procedure.

    ERIC Educational Resources Information Center

    Williams, Robert T.

    Vision is a complex process involving three phases: physical (acuity), physiological (integrative), and psychological (perceptual). Although these phases cannot be considered discrete, they provide the basis for the visual screening procedure used by the Reading Services of Colorado State University and described in this document. Ten tests are…

  18. Visual Literacy Yearbook.

    ERIC Educational Resources Information Center

    Montebello Unified School District, CA.

    This yearbook describes the program undertaken by the Montebello, California Unified School District to assist children's development in the area of language arts by giving them the opportunity to use cameras to record their visual experience and by then using the resulting pictures, slides and films as the basis of language arts experiences. It…

  19. Perception, Cognition, and Visualization.

    ERIC Educational Resources Information Center

    Arnheim, Rudolf

    1991-01-01

    Described are how pictures can combine aspects of naturalistic representation with more formal shapes to enhance cognitive understanding. These "diagrammatic" shapes derive from geometrical elementary and thereby bestow visual concreteness to concepts conveyed by the pictures. Leonardo da Vinci's anatomical drawings are used as examples…

  20. Visualization of Traffic Accidents

    NASA Technical Reports Server (NTRS)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  1. Solar System Visualizations

    NASA Technical Reports Server (NTRS)

    Brown, Alison M.

    2005-01-01

    Solar System Visualization products enable scientists to compare models and measurements in new ways that enhance the scientific discovery process, enhance the information content and understanding of the science results for both science colleagues and the public, and create.visually appealing and intellectually stimulating visualization products. Missions supported include MER, MRO, and Cassini. Image products produced include pan and zoom animations of large mosaics to reveal the details of surface features and topography, animations into registered multi-resolution mosaics to provide context for microscopic images, 3D anaglyphs from left and right stereo pairs, and screen captures from video footage. Specific products include a three-part context animation of the Cassini Enceladus encounter highlighting images from 350 to 4 meter per pixel resolution; Mars Reconnaissance Orbiter screen captures illustrating various instruments during assembly and testing at the Payload Hazardous Servicing Facility at Kennedy Space Center; and an animation of Mars Exploration Rover Opportunity's 'Rub al Khali' panorama where the rover was stuck in the deep fine sand for more than a month. This task creates new visualization products that enable new science results and enhance the public's understanding of the Solar System and NASA's missions of exploration.

  2. Challenges for Visual Analytics

    SciTech Connect

    Thomas, James J.; Kielman, Joseph

    2009-09-23

    Visual analytics has seen unprecedented growth in its first five years of mainstream existence. Great progress has been made in a short time, yet great challenges must be met in the next decade to provide new technologies that will be widely accepted by societies throughout the world. This paper sets the stage for some of those challenges in an effort to provide the stimulus for the research, both basic and applied, to address and exceed the envisioned potential for visual analytics technologies. We start with a brief summary of the initial challenges, followed by a discussion of the initial driving domains and applications, as well as additional applications and domains that have been a part of recent rapid expansion of visual analytics usage. We look at the common characteristics of several tools illustrating emerging visual analytics technologies, and conclude with the top ten challenges for the field of study. We encourage feedback and collaborative participation by members of the research community, the wide array of user communities, and private industry.

  3. Extreme Scale Visual Analytics

    SciTech Connect

    Wong, Pak C.; Shen, Han-Wei; Pascucci, Valerio

    2012-05-08

    Extreme-scale visual analytics (VA) is about applying VA to extreme-scale data. The articles in this special issue examine advances related to extreme-scale VA problems, their analytical and computational challenges, and their real-world applications.

  4. Monocular visual ranging

    NASA Astrophysics Data System (ADS)

    Witus, Gary; Hunt, Shawn

    2008-04-01

    The vision system of a mobile robot for checkpoint and perimeter security inspection performs multiple functions: providing surveillance video, providing high resolution still images, and providing video for semi-autonomous visual navigation. Mid-priced commercial digital cameras support the primary inspection functions. Semi-autonomous visual navigation is a tertiary function whose purpose is to reduce the burden of teleoperation and free the security personnel for their primary functions. Approaches to robot visual navigation require some form of depth perception for speed control to prevent the robot from colliding with objects. In this paper present the initial results of an exploration of the capabilities and limitations of using a single monocular commercial digital camera for depth perception. Our approach combines complementary methods in alternating stationary and moving behaviors. When the platform is stationary, it computes a range image from differential blur in the image stack collected at multiple focus settings. When the robot is moving, it extracts an estimate of range from the camera auto-focus function, and combines this with an estimate derived from angular expansion of a constellation of visual tracking points.

  5. Basic Skills: Visual Arts.

    ERIC Educational Resources Information Center

    Kentucky State Dept. of Education, Frankfort.

    A curriculum guide for the visual arts is presented. The goal of elementary and middle school education in the four arts disciplines is the development of basic understanding and skills by every student. In secondary education the aim is to continue a sequential curriculum for those students who study the arts. This document is intended as a guide…

  6. NCI Visuals Online

    Cancer.gov

    NCI Visuals Online contains images from the collections of the National Cancer Institute's Office of Communications and Public Liaison, including general biomedical and science-related images, cancer-specific scientific and patient care-related images, and portraits of directors and staff of the National Cancer Institute.

  7. 3D reservoir visualization

    SciTech Connect

    Van, B.T.; Pajon, J.L.; Joseph, P. )

    1991-11-01

    This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.

  8. Visual Literacy in Science

    ERIC Educational Resources Information Center

    McTigue, Erin; Croix, Amanda

    2010-01-01

    While diagrams make the text more visually appealing and provide an image of the text, they also do much more. Subsequently, the authors designed a series of lessons for students to discover the many purposes of graphics in science. A particular utility of these interdisciplinary lessons is that they are used with any science text featuring visual…

  9. Sounds Exaggerate Visual Shape

    ERIC Educational Resources Information Center

    Sweeny, Timothy D.; Guzman-Martinez, Emmanuel; Ortega, Laura; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    While perceiving speech, people see mouth shapes that are systematically associated with sounds. In particular, a vertically stretched mouth produces a /woo/ sound, whereas a horizontally stretched mouth produces a /wee/ sound. We demonstrate that hearing these speech sounds alters how we see aspect ratio, a basic visual feature that contributes…

  10. Visualizing SPH Cataclysmic Variable Accretion Disk Simulations with Blender

    NASA Astrophysics Data System (ADS)

    Kent, Brian R.; Wood, Matthew A.

    2015-01-01

    We present innovative ways to use Blender, a 3D graphics package, to visualize smoothed particle hydrodynamics particle data of cataclysmic variable accretion disks. We focus on the methods of shape key data constructs to increasedata i/o and manipulation speed. The implementation of the methods outlined allow for compositing of the various visualization layers into a final animation. The viewing of the disk in 3D from different angles can allow for a visual analysisof the physical system and orbits. The techniques have a wide ranging set of applications in astronomical visualization,including both observation and theoretical data.

  11. Visual Perception in Correlated Noise

    NASA Astrophysics Data System (ADS)

    Myers, Kyle Jean

    known to exist in the human visual system. We shall show that the presence of such a mechanism can explain the degradation of human observer performance in correlated noise.

  12. Improving visual skills: a new internet application

    NASA Astrophysics Data System (ADS)

    Powers, M. K.

    2006-09-01

    The object of this paper is to describe an internet-based system and technique for improving performance on visuomotor tasks. The technique can be used in any setting where the internet can be accessed, and can be adapted for improving a variety of visual tasks. Sample learning curves for acquiring the visual skills of accommodative facility, saccadic tracking and binocular fusion are presented, from three subjects ages 7 and 9, including one child diagnosed with autism. The database structure of the system allows powerful data storage and retrieval options for use in providing feedback on performance, online monitoring of progress by an external observer, and statistical analysis of group and individual data.

  13. A Visualization Tool for Meteorological Data

    1999-09-28

    Graphical user interfaces (GUIs) have been buit to visualize surface and upper-meteorology data for any global location and time of interest. The user selects a domain (geographic location and bounding range) and time of interest using the Gui, and a file containing coded observations is accessed and decoded. two styles of the GUI have been built, depending on whether surface or upper air visualization is desired. The former indicates weather conditions near the earth''s surface,more » while the latter illustrates a vertical profile of atmospheric conditions.« less

  14. High visual demand following theta burst stimulation modulates the effect on visual cortex excitability

    PubMed Central

    Brückner, Sabrina; Kammer, Thomas

    2015-01-01

    Modulatory effects of repetitive transcranial magnetic stimulation (TMS) depend on the activity of the stimulated cortical area before, during, and even after application. In the present study, we investigated the effects of theta burst stimulation (TBS) on visual cortex excitability using phosphene threshold (PTs). In a between-group design either continuous or intermittent TBS was applied with 100% of individual PT intensity. We varied visual demand following stimulation in form of high demand (acuity task) or low demand (looking at the wall). No change of PTs was observed directly after TBS. We found increased PTs only if subjects had high visual demand following continuous TBS. With low visual demand following stimulation no change of PT was observed. Intermittent TBS had no effect on visual cortex excitability at all. Since other studies showed increased PTs following continuous TBS using subthreshold intensities, our results highlight the importance of stimulation intensity applying TBS to the visual cortex. Furthermore, the state of the neurons in the stimulated cortex area not only before but also following TBS has an important influence on the effects of stimulation, making it necessary to scrupulously control for activity during the whole experimental session in a study. PMID:26578935

  15. Visual Environments for CFD Research

    NASA Technical Reports Server (NTRS)

    Watson, Val; George, Michael W. (Technical Monitor)

    1994-01-01

    This viewgraph presentation gives an overview of the visual environments for computational fluid dynamics (CFD) research. It includes details on critical needs from the future computer environment, features needed to attain this environment, prospects for changes in and the impact of the visualization revolution on the human-computer interface, human processing capabilities, limits of personal environment and the extension of that environment with computers. Information is given on the need for more 'visual' thinking (including instances of visual thinking), an evaluation of the alternate approaches for and levels of interactive computer graphics, a visual analysis of computational fluid dynamics, and an analysis of visualization software.

  16. Four types of ensemble coding in data visualizations.

    PubMed

    Szafir, Danielle Albers; Haroz, Steve; Gleicher, Michael; Franconeri, Steven

    2016-01-01

    Ensemble coding supports rapid extraction of visual statistics about distributed visual information. Researchers typically study this ability with the goal of drawing conclusions about how such coding extracts information from natural scenes. Here we argue that a second domain can serve as another strong inspiration for understanding ensemble coding: graphs, maps, and other visual presentations of data. Data visualizations allow observers to leverage their ability to perform visual ensemble statistics on distributions of spatial or featural visual information to estimate actual statistics on data. We survey the types of visual statistical tasks that occur within data visualizations across everyday examples, such as scatterplots, and more specialized images, such as weather maps or depictions of patterns in text. We divide these tasks into four categories: identification of sets of values, summarization across those values, segmentation of collections, and estimation of structure. We point to unanswered questions for each category and give examples of such cross-pollination in the current literature. Increased collaboration between the data visualization and perceptual psychology research communities can inspire new solutions to challenges in visualization while simultaneously exposing unsolved problems in perception research. PMID:26982369

  17. Direction specific biases in human visual and vestibular heading perception.

    PubMed

    Crane, Benjamin T

    2012-01-01

    Heading direction is determined from visual and vestibular cues. Both sensory modalities have been shown to have better direction discrimination for headings near straight ahead. Previous studies of visual heading estimation have not used the full range of stimuli, and vestibular heading estimation has not previously been reported. The current experiments measure human heading estimation in the horizontal plane to vestibular, visual, and spoken stimuli. The vestibular and visual tasks involved 16 cm of platform or visual motion. The spoken stimulus was a voice command speaking a heading angle. All conditions demonstrated direction dependent biases in perceived headings such that biases increased with headings further from the fore-aft axis. The bias was larger with the visual stimulus when compared with the vestibular stimulus in all 10 subjects. For the visual and vestibular tasks precision was best for headings near fore-aft. The spoken headings had the least bias, and the variation in precision was less dependent on direction. In a separate experiment when headings were limited to ± 45°, the biases were much less, demonstrating the range of headings influences perception. There was a strong and highly significant correlation between the bias curves for visual and spoken stimuli in every subject. The correlation between visual-vestibular and vestibular-spoken biases were weaker but remained significant. The observed biases in both visual and vestibular heading perception qualitatively resembled predictions of a recent population vector decoder model (Gu et al., 2010) based on the known distribution of neuronal sensitivities.

  18. Visual impairment in FOXG1-mutated individuals and mice.

    PubMed

    Boggio, E M; Pancrazi, L; Gennaro, M; Lo Rizzo, C; Mari, F; Meloni, I; Ariani, F; Panighini, A; Novelli, E; Biagioni, M; Strettoi, E; Hayek, J; Rufa, A; Pizzorusso, T; Renieri, A; Costa, M

    2016-06-01

    The Forkead Box G1 (FOXG1 in humans, Foxg1 in mice) gene encodes for a DNA-binding transcription factor, essential for the development of the telencephalon in mammalian forebrain. Mutations in FOXG1 have been reported to be involved in the onset of Rett Syndrome, for which sequence alterations of MECP2 and CDKL5 are known. While visual alterations are not classical hallmarks of Rett syndrome, an increasing body of evidence shows visual impairment in patients and in MeCP2 and CDKL5 animal models. Herein we focused on the functional role of FOXG1 in the visual system of animal models (Foxg1(+/Cre) mice) and of a cohort of subjects carrying FOXG1 mutations or deletions. Visual physiology of Foxg1(+/Cre) mice was assessed by visually evoked potentials, which revealed a significant reduction in response amplitude and visual acuity with respect to wild-type littermates. Morphological investigation showed abnormalities in the organization of excitatory/inhibitory circuits in the visual cortex. No alterations were observed in retinal structure. By examining a cohort of FOXG1-mutated individuals with a panel of neuro-ophthalmological assessments, we found that all of them exhibited visual alterations compatible with high-level visual dysfunctions. In conclusion our data show that Foxg1 haploinsufficiency results in an impairment of mouse and human visual cortical function. PMID:27001178

  19. Electroretinography and Visual Evoked Potentials in Childhood Brain Tumor Survivors.

    PubMed

    Pietilä, Sari; Lenko, Hanna L; Oja, Sakari; Koivisto, Anna-Maija; Pietilä, Timo; Mäkipernaa, Anne

    2016-07-01

    This population-based cross-sectional study evaluates the clinical value of electroretinography and visual evoked potentials in childhood brain tumor survivors. A flash electroretinography and a checkerboard reversal pattern visual evoked potential (or alternatively a flash visual evoked potential) were done for 51 survivors (age 3.8-28.7 years) after a mean follow-up time of 7.6 (1.5-15.1) years. Abnormal electroretinography was obtained in 1 case, bilaterally delayed abnormal visual evoked potentials in 22/51 (43%) cases. Nine of 25 patients with infratentorial tumor location, and altogether 12 out of 31 (39%) patients who did not have tumors involving the visual pathways, had abnormal visual evoked potentials. Abnormal electroretinographies are rarely observed, but abnormal visual evoked potentials are common even without evident anatomic lesions in the visual pathway. Bilateral changes suggest a general and possibly multifactorial toxic/adverse effect on the visual pathway. Electroretinography and visual evoked potential may have clinical and scientific value while evaluating long-term effects of childhood brain tumors and tumor treatment.

  20. Direction Specific Biases in Human Visual and Vestibular Heading Perception

    PubMed Central

    Crane, Benjamin T.

    2012-01-01

    Heading direction is determined from visual and vestibular cues. Both sensory modalities have been shown to have better direction discrimination for headings near straight ahead. Previous studies of visual heading estimation have not used the full range of stimuli, and vestibular heading estimation has not previously been reported. The current experiments measure human heading estimation in the horizontal plane to vestibular, visual, and spoken stimuli. The vestibular and visual tasks involved 16 cm of platform or visual motion. The spoken stimulus was a voice command speaking a heading angle. All conditions demonstrated direction dependent biases in perceived headings such that biases increased with headings further from the fore-aft axis. The bias was larger with the visual stimulus when compared with the vestibular stimulus in all 10 subjects. For the visual and vestibular tasks precision was best for headings near fore-aft. The spoken headings had the least bias, and the variation in precision was less dependent on direction. In a separate experiment when headings were limited to ±45°, the biases were much less, demonstrating the range of headings influences perception. There was a strong and highly significant correlation between the bias curves for visual and spoken stimuli in every subject. The correlation between visual-vestibular and vestibular-spoken biases were weaker but remained significant. The observed biases in both visual and vestibular heading perception qualitatively resembled predictions of a recent population vector decoder model (Gu et al., 2010) based on the known distribution of neuronal sensitivities. PMID:23236490