WorldWideScience

Sample records for crystal ball gazing

  1. Crystal Ball Functional Model

    Science.gov (United States)

    Plotnick, David

    2016-09-01

    The A2 collaboration of the MAinz MIkrotron is dedicated to studying meson production and nucleon structure and behavior via photon scattering. The photons are made via bremsstrahlung process and energy-tagged using the Glasgow Photon tagger. The photon beam then interacts in a variety of targets: cryogenic, polarized or solid state, and scattered particles deposit their energy within the NaI crystals. Scintillators are able to give results on particles energy and time. Events are reconstructed by combining information from the Tagging spectrometer, the Crystal Ball detector, the TAPS forward wall spectrometer, a Cherenkov detector, and multi-wire proportional chambers. To better understand the detector and experimental events, a live display was built to show energies deposited in crystals in real-time. In order to show a range of energies and particles, addressable LEDs that are individually programmable were used. To best replicate the Crystal Ball, 3D printing technology was employed to build a similar highly segmented icosahedron that can hold each LED, creating a 3D representation of what photons see during experiments. The LEDs were controlled via Arduino microcontroller. Finally, we implemented the Experimental Physics and Industrial Control System to grab live event data, and a simple program converts this data in to color and crystal number data that is able to communicate with the Arduino. Using these simple parts, we can better visualize and understand the tools used in nuclear physics. This material is based upon work supported by the National Science Foundation Grant No. IIA-1358175.

  2. Crystal Ball Replica

    Science.gov (United States)

    Ajamian, John

    2016-09-01

    The A2 collaboration of the Institute for Nuclear Physics of Johannes Gutenberg University performs research on (multiple) meson photoproduction and nucleon structure and dynamics using a high energy polarized photon beam at specific targets. Particles scattered from the target are detected in the Crystal Ball, or CB. The CB is composed of 672 NaI crystals that surround the target and can analyze particle type and energy of ejected particles. Our project was to create a replica of the CB that could display what was happening in real time on a 3 Dimensional scale replica. Our replica was constructed to help explain the physics to the general public, be used as a tool when calibrating each of the 672 NaI crystals, and to better analyze the electron showering of particles coming from the target. This poster will focus on the hardware steps necessary to construct the replica and wire the 672 programmable LEDS in such a way that they can be mapped to correspond to the Crystal Ball elements. George Washington NSF Grant.

  3. Crystal ball single event display

    Energy Technology Data Exchange (ETDEWEB)

    Grosnick, D.; Gibson, A. [Valparaiso Univ., IN (United States). Dept. of Physics and Astronomy; Allgower, C. [Argonne National Lab., IL (United States). High Energy Physics Div.; Alyea, J. [Valparaiso Univ., IN (United States). Dept. of Physics and Astronomy]|[Argonne National Lab., IL (United States). High Energy Physics Div.

    1997-10-15

    The Single Event Display (SED) is a routine that is designed to provide information graphically about a triggered event within the Crystal Ball. The SED is written entirely in FORTRAN and uses the CERN-based HICZ graphing package. The primary display shows the amount of energy deposited in each of the NaI crystals on a Mercator-like projection of the crystals. Ten different shades and colors correspond to varying amounts of energy deposited within a crystal. Information about energy clusters is displayed on the crystal map by outlining in red the thirteen (or twelve) crystals contained within a cluster and assigning each cluster a number. Additional information about energy clusters is provided in a series of boxes containing useful data about the energy distribution among the crystals within the cluster. Other information shown on the event display include the event trigger type and data about {pi}{sup o}`s and {eta}`s formed from pairs of clusters as found by the analyzer. A description of the major features is given, along with some information on how to install the SED into the analyzer.

  4. A look into the Medical and Veterinary Entomology crystal ball.

    Science.gov (United States)

    Dantas-Torres, F; Cameron, M M; Colwell, D D; Otranto, D

    2014-08-01

    Medical and Veterinary Entomology (MVE) represents a leading periodical in its field and covers many aspects of the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. Since the first issue of the journal, researchers working in both developed and developing countries have published in MVE, with direct impact on current knowledge in the field. An increasing number of articles dealing with the epidemiology and transmission of vector-borne pathogens have been published in MVE, reflecting rapid changes in vector distribution, pathogen transmission and host-arthropod interactions. This article represents a gaze into the crystal ball in which we identify areas of increasing interest, discuss the main changes that have occurred in the epidemiology of parasitic arthropods since the first issue of MVE, and predict the principal scientific topics that might arise in the next 25 years for scientists working in medical and veterinary entomology.

  5. Results on charmonium from the Crystal Ball

    CERN Document Server

    Partridge, R; Bloom, Elliott D; Bulos, F; Burnett, T; Cavalli-Sforza, M; Chestnut, R; Coyne, D; Gaiser, J; Godfrey, G; Hofstadter, R; Kiesling, C; Kirkbride, I; Kolanoski, H; Kollmann, W; Liberman, A; O'Reilly, J; Oreglia, M J; Peck, C; Porter, F; Richardson, M; Sadrozinski, H F W; Strauch, K; Tompkins, J; Wacker, K

    1979-01-01

    Results from the Crystal Ball experiment at SPEAR are presented. A preliminary analysis of the 3 photon final state from the J/ psi (3095) and of the cascade decays of the psi '(3684) yield new upper limits on the controversial states X(2820), chi (3455) and the even C- parity state at 3.59 GeV. From inclusive gamma -ray spectra of the J/ psi and psi ' preliminary branching ratios for psi ' to chi states and upper limits for J/ psi , psi ' to eta /sub c/, eta /sub c/' are given. (15 refs).

  6. Gazes

    DEFF Research Database (Denmark)

    Khawaja, Iram

    This article is based on fieldwork with young Muslims in Copenhagen and focuses on how they navigate the visibility and embodiment of Muslim otherness in their everyday life. The concept of panoptical gazes are developed in regard to the young Muslims’ narratives of being looked upon, and the dif......This article is based on fieldwork with young Muslims in Copenhagen and focuses on how they navigate the visibility and embodiment of Muslim otherness in their everyday life. The concept of panoptical gazes are developed in regard to the young Muslims’ narratives of being looked upon......, and the different strategies of positioning they utilize are studied and identified. The first strategy is to confront stereotyping prejudices and gazes, thereby attempting to position oneself in a counteracting way. The second is to transform and try to normalise external characteristics, such as clothing...... and other symbols that indicate Muslimness. A third strategy is to play along and allow the prejudice in question to remain unchallenged. A fourth is to join and participate in religious communities and develop an alternate sense of belonging to a wider community of Muslims. The concept of panoptical gazes...

  7. Recent results from the Crystal Ball

    Energy Technology Data Exchange (ETDEWEB)

    Porter, F.C.

    1981-09-01

    During the past year, the Crystal Ball experiment has continued the investigation of e/sup +/e/sup -/ interactions at SPEAR. In the course of the year, we have slightly more than doubled the available datasets at the J/psi (to 2.2 x 10/sup 6/ produced J/psi) and the psi' (to 1.8 x 10/sup 6/ produced psi') resonances, and have increased the data in the 5.2 to 7.4 GeV center-of-mass (E/sub c.m./) region. The present discussion is limited to recent results obtained with the J/psi and psi' datasets, primarily dealing with transitions among the charmonium bound states.

  8. Gazes

    DEFF Research Database (Denmark)

    Khawaja, Iram

    , and the different strategies of positioning they utilize are studied and identified. The first strategy is to confront stereotyping prejudices and gazes, thereby attempting to position oneself in a counteracting way. The second is to transform and try to normalise external characteristics, such as clothing...... and other symbols that indicate Muslimness. A third strategy is to play along and allow the prejudice in question to remain unchallenged. A fourth is to join and participate in religious communities and develop an alternate sense of belonging to a wider community of Muslims. The concept of panoptical gazes...... are related to narratives on belonging, and the embodied experience of home which points towards new avenues of understanding the process of othering and the possibilities of negotiating the position as Other....

  9. A simple alternative to the Crystal Ball function

    CERN Document Server

    Das, Souvik

    2016-01-01

    We present a simple alternative to the Crystal Ball function that has an exponential tail stitched to a Gaussian core. It has one parameter less than the Crystal Ball function and, where appropriate, offers more stable fits to peaks that continue into exponential tails. The function may also be extended with two exponential tails on each side of the Gaussian, and this has two parameters less than the corresponding double-shouldered Crystal Ball function. This function has been used to model background and signal processes in a recent Higgs pair production search and may be of versatile use in experimental physics and other fields.

  10. Synthesis of porous carbon balls from spherical colloidal crystal templates.

    Science.gov (United States)

    Kim, Youngchan; Cho, Chang-Yeol; Kang, Ji-Hwan; Cho, Young-Sang; Moon, Jun Hyuk

    2012-07-17

    Spherical inverse opal (IO) porous carbon was produced utilizing silica colloidal crystal spheres as templates. The spherical colloidal crystals were obtained through the self-assembly of monodisperse particles inside an emulsion droplet with confined geometry. The templates were inverted using a carbon precursor, phenol-formaldehyde (PF) resol. We demonstrated a two-step synthesis involving the subsequent infiltration of the PF resol precursor into the spherical colloidal crystal template and a one-step synthesis using a silica colloidal solution containing dissolved PF resol. In the former case, the sizes of the IO carbon balls were controlled by the size of the colloidal crystal templates, and diameters of a few micrometers up to 50 μm were obtained. The average diameter of the macropores created by the silica particles was 230 nm. Moreover, meso-/macroporous IO carbon balls were created using block-copolymer templates in the PF resol. In the one-step synthesis, the concentration of PF resol in the colloidal solution controlled the diameter of the IO carbon balls. IO balls smaller than 3 μm were obtained from the direct addition of 5% PF resol. The one-step synthesis produced rather irregular porous structures reflecting the less ordered crystallization processes inside the spherical colloidal crystals. Nitrogen adsorption and cyclic voltammetry measurements were conducted to measure the specific area and electroactive surface area of the IO carbon balls. The specific area of the mesopores-incorporated IO carbon balls was 1.3 times higher than that of bare IO carbon balls. Accordingly, the meso-/macroporous porous carbon balls exhibited higher electrocatalytic properties than the macroporous carbon balls.

  11. A new {eta} facility using the Crystal Ball

    Energy Technology Data Exchange (ETDEWEB)

    Tippens, W.B. [University of California, Los Angeles, Los Angeles, California 90024 (United States)

    1995-07-10

    The SLAC Crystal Ball detector is part of a proposed program at the AGS to measure rare and forbidden {eta} decays. It`s 4{pi} geometry also makes many interesting studies in baryon spectroscopy possible. A description of the detector`s capabilities at the AGS will be given. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  12. A new ɛ facility using the Crystal Ball

    Science.gov (United States)

    Tippens, W. B.

    1995-07-01

    The SLAC Crystal Ball detector is part of a proposed program at the AGS to measure rare and forbidden η decays. It's 4π geometry also makes many interesting studies in baryon spectroscopy possible. A description of the detector's capabilities at the AGS will be given.

  13. Unexpected Expectations The Curiosities of a Mathematical Crystal Ball

    CERN Document Server

    Wapner, Leonard M

    2012-01-01

    Unexpected Expectations: The Curiosities of a Mathematical Crystal Ball explores how paradoxical challenges involving mathematical expectation often necessitate a reexamination of basic premises. The author takes you through mathematical paradoxes associated with seemingly straightforward applications of mathematical expectation and shows how these unexpected contradictions may push you to reconsider the legitimacy of the applications. The book requires only an understanding of basic algebraic operations and includes supplemental mathematical background in chapter appendices. After a history o

  14. Tests of C and CP using the Crystal Ball

    Science.gov (United States)

    Tippens, W. B.

    1995-07-01

    The installation of the SLAC Crystal Ball at BNL will initially provide measurements on several rare and forbidden neutral decays of the η. We intend to set first limits on several decay modes such as 2π0, 4π0, and 2π0γ. The first two are tests of CP invariance and the latter a test of C. In addition, we intend to improve the upper limit for the C violating decay to 3γ by roughly two orders of magnitude and make a precision measurement of the rare decay mode π0γγ.

  15. Social Media and Big Data – Cracks in the Crystal Ball?

    NARCIS (Netherlands)

    Westera, Wim

    2013-01-01

    Westera, W. (2013, 14 October). Social Media and Big Data – Cracks in the Crystal Ball? Invited e-paper at ESOMAR RW Connect. http://rwconnect.esomar.org/using-social-media-for-market-analysis-cracks-in-the-alleged-crystal-ball/

  16. Social Media and Big Data – Cracks in the Crystal Ball?

    NARCIS (Netherlands)

    Westera, Wim

    2013-01-01

    Westera, W. (2013, 14 October). Social Media and Big Data – Cracks in the Crystal Ball? Invited e-paper at ESOMAR RW Connect. http://rwconnect.esomar.org/using-social-media-for-market-analysis-cracks-in-the-alleged-crystal-ball/

  17. Hadron spectroscopy with the crystal ball at the AGS

    Science.gov (United States)

    Tippens, B.

    1998-05-01

    The recent installation of the Crystal Ball (CB) on the C6 beamline at the AGS marks the beginning of a new diverse program in hadron spectroscopy at BNL. Some of its goals are to improve the determination of the masses, widths and decay modes of several baryon resonances, to search for possible exotic states such as pentaquarks and hybrids, to determine the η-n scattering length, and to measure photoproduction of K- mesons from Λ and Σ hyperons using the technique of detailed balance. In the spring of 1997, we conducted a two week engineering run and a two week data run looking at all neutral final states from π-p interactions. A description of the experimental setup and performance of the detector is given along with some preliminary results from π-p→ηn.

  18. Crystal growth and the steady-state grain size during high-energy ball-milling

    DEFF Research Database (Denmark)

    Mørup, Steen; Jiang, Jianzhong; Bødker, Franz

    2001-01-01

    The change in crystal size during high-energy ball-milling of hematite and zinc sulphide powders with initial average crystal size of 8 nm and 4 nm, respectively, has been investigated by X-ray powder diffraction and transmission electron microscopy. It is found that the crystal size increases wi...

  19. Crystallization of acetaminophen form II by plastic-ball-assisted ultrasonic irradiation

    Science.gov (United States)

    Mori, Yoichiro; Maruyama, Mihoko; Takahashi, Yoshinori; Yoshikawa, Hiroshi Y.; Okada, Shino; Adachi, Hiroaki; Sugiyama, Shigeru; Takano, Kazufumi; Murakami, Satoshi; Matsumura, Hiroyoshi; Inoue, Tsuyoshi; Yoshimura, Masashi; Mori, Yusuke

    2017-02-01

    We report a novel method for crystallizing the metastable polymorph form II of acetaminophen by using a plastic ball during ultrasonic irradiation. The presence of a plastic ball during ultrasonic irradiation of aqueous acetaminophen solution effectively increased the probability and reduced the induction time of form II crystallization. This method facilitated both laboratory- and large-scale production of form II crystals. Our method has significant advantages for practical application of form II because it can reduce the time to production and enable large-scale production.

  20. Gazing into the Crystal Ball: Using Scenarios for Future Visioning of a Distance Learning Library Service

    Science.gov (United States)

    Casey, Anne Marie; Cawthorne, Jon E.; Citro, Kathleen

    2014-01-01

    This article describes the use of scenarios as a tool to assist a large distance learning library service in its strategic planning. Through a description of the scenario process from beginning to end, the authors detail the steps that the library director and the consultant took initially; their missteps; and the successful conclusion. This study…

  1. Measurement of neutron detection efficiencies in NaI using the Crystal Ball detector

    Energy Technology Data Exchange (ETDEWEB)

    Stanislaus, T.D.S.; Koetke, D.D. E-mail: donald.koetke@valpo.edu; Allgower, C.; Bekrenev, V.; Benslama, K.; Berger, E.; Briscoe, W.J.; Clajus, M.; Comfort, J.R.; Craig, K.; Gibson, A.; Grosnick, D.; Huber, G.M.; Isenhower, D.; Kasprzyk, T.; Knecht, N.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Kycia, T.; Lolos, G.J.; Lopatin, I.; Manley, D.M.; Manweiler, R.; Marusic, A.; McDonald, S.; Nefkens, B.M.K.; Olmsted, J.; Papandreou, Z.; Peaslee, D.; Peterson, R.J.; Phaisangittisakul, N.; Pulver, M.; Ramirez, A.F.; Sadler, M.; Shafi, A.; Slaus, I.; Spinka, H.; Starostin, A.; Staudenmaier, H.M.; Supek, I.; Thoms, J.; Tippens, W.B

    2001-04-21

    We report on a measurement of the neutron detection efficiency in NaI crystals in the Crystal Ball (CB) detector obtained from a study of {pi}{sup -}p{yields}{pi} degree sign n reactions at the Brookhaven National Laboratory AGS. A companion GEANT-based Monte Carlo study has been done to simulate these reactions in the CB, and a comparison with the data is provided.

  2. A new measurement of the neutron detection efficiency for the NaI Crystal Ball detector

    CERN Document Server

    Martemianov, M; Demissie, B T; Marinides, Z; Akondi, C S; Annand, J R M; Arends, H J; Beck, R; Borisov, N; Braghieri, A; Briscoe, W J; Cherepnya, S; Collicott, C; Costanza, S; Downie, E J; Dieterle, M; Bondy, M I Ferretti; Filkov, L V; Garni, S; Glazier, D I; Glowa, D; Gradl, W; Gurevich, G; Hornidge, D; Huber, G M; Kaeser, A; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Krusche, B; Lazarev, A; Linturi, J M; Lisin, V; Livingston, K; MacGregor, I J D; Manley, D M; Martel, P P; Middleton, D G; Miskimen, R; Mushkarenkov, A; Neganov, A; Neiser, A; Oberle, M; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Prakhov, S; Ron, G; Rostomyan, T; Sarty, A; Schott, D M; Schumann, S; Sokhoyan, V; Steffen, O; Strakovsky, I I; Strub, Th; Supek, I; Thiel, M; Thomas, A; Unverzagt, M; Usov, Yu A; Wagner, S; Watts, D P; Wettig, J; Werthmuller, D; Witthauer, L; Wolfes, M

    2015-01-01

    We report on a measurement of the neutron detection efficiency in NaI crystals in the Crystal Ball detector obtained from a study of single p0 photoproduction on deuterium using the tagged photon beam at the Mainz Microtron. The results were obtained up to a neutron energy of 400 MeV. They are compared to previous measurements made more than 15 years ago at the pion beam at the BNL AGS.

  3. Measurement of neutron detection efficiencies in NaI using the Crystal Ball detector

    Science.gov (United States)

    Stanislaus, T. D. S.; Koetke, D. D.; Allgower, C.; Bekrenev, V.; Benslama, K.; Berger, E.; Briscoe, W. J.; Clajus, M.; Comfort, J. R.; Craig, K.; Gibson, A.; Grosnick, D.; Huber, G. M.; Isenhower, D.; Kasprzyk, T.; Knecht, N.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Kycia, T.; Lolos, G. J.; Lopatin, I.; Manley, D. M.; Manweiler, R.; Marusic, A.; McDonald, S.; Nefkens, B. M. K.; Olmsted, J.; Papandreou, Z.; Peaslee, D.; Peterson, R. J.; Phaisangittisakul, N.; Pulver, M.; Ramirez, A. F.; Sadler, M.; Shafi, A.; Slaus, I.; Spinka, H.; Starostin, A.; Staudenmaier, H. M.; Supek, I.; Thoms, J.; Tippens, W. B.

    2001-04-01

    We report on a measurement of the neutron detection efficiency in NaI crystals in the Crystal Ball (CB) detector obtained from a study of π-p→ π°n reactions at the Brookhaven National Laboratory AGS. A companion GEANT-based Monte Carlo study has been done to simulate these reactions in the CB, and a comparison with the data is provided.

  4. Efficiency of various lattices from hard ball to soft ball: theoretical study of thermodynamic properties of dendrimer liquid crystal from atomistic simulation.

    Science.gov (United States)

    Li, Youyong; Lin, Shiang-Tai; Goddard, William A

    2004-02-18

    Self-assembled supramolecular organic liquid crystal structures at nanoscale have potential applications in molecular electronics, photonics, and porous nanomaterials. Most of these structures are formed by aggregation of soft spherical supramolecules, which have soft coronas and overlap each other in the packing process. Our main focus here is to study the possible packing mechanisms via molecular dynamics simulations at the atomistic level. We consider the relative stability of various lattices packed by the soft dendrimer balls, first synthesized and characterized by Percec et al. (J. Am. Chem. Soc. 1997, 119, 1539) with different packing methods. The dendrons, which form the soft dendrimer balls, have the character of a hard aromatic region from the point of the cone to the edge with C(12) alkane "hair". After the dendrons pack into a sphere, the core of the sphere has the hard aromatic groups, while the surface is covered with the C(12) alkane "hair". In our studies, we propose three ways to organize the hair on the balls, Smooth/Valentino balls, Sticky/Einstein balls, and Asymmetric/Punk balls, which lead to three different packing mechanisms, Slippery, Sticky, and Anisotropic, respectively. We carry out a series of molecular dynamics (MD) studies on three plausible crystal structures (A15, FCC, and BCC) as a function of density and analyze the MD based on the vibrational density of state (DoS) method to extract the enthalpy, entropy, and free energies of these systems. We find that anisotropic packed A15 is favored over FCC, BCC lattices. Our predicted X-ray intensities of the best structures are in excellent agreement with experiment. "Anisotropic ball packing" proposed here plays an intermediate role between the enthalpy-favored "disk packing" and entropy-favored "isotropic ball packing", which explains the phase transitions at different temperatures. Free energies of various lattices at different densities are essentially the same, indicating that the

  5. Synthesis of Cu(In,Ga)Se{sub 2} crystals using a crank ball mill

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Suzuka; Noji, Hideki; Akaki, Yoji [Miyakonojo National College of Technology, 473-1 Yoshio, Miyakonojo Miyazaki 885-8567 (Japan); Okamoto, Tomoichiro [Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2015-06-15

    Cu(In,Ga)Se{sub 2} (CIGS) crystals were synthesized by a mechanochemical (MC) process using a crank ball mill. The molar ratios of starting materials were Cu:In:Ga:Se=1:1-x:x:2 (0≤x≤1) and Cu:In:Ga:Se=1:0.7:0.3:y (2≤y≤3). The reaction time reduced with decreasing Se and Ga molar ratios. The collection rate decreased with longer reaction times. From XRD patterns, we confirmed that the CuInSe{sub 2} and/or CuGaSe{sub 2}crystals were successfully grown when the powders reacted. Although the crystals grown with a selenium molar ration of 2 were Se-poor, those grown at a molar ratio of 3 were Se-rich. When Se increasing molar ratio, Cu, In, and Ga were away from the stoichiometric. With a molar ratio of Cu:In:Ga:Se=1:0.7:0.3:2.5∝2.7, their composition became stoichiometric. Crystal morphology was varied. CIGS crystals were thus successfully synthesized using a crank ball mill. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Crystal Ball: On the Future High Energy Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2015-09-20

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

  7. Crystal Ball: On the Future High Energy Colliders

    CERN Document Server

    Shiltsev, Vladimir

    2015-01-01

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of ...

  8. Fabrication of flexible photonic crystal using alumina ball inserted Teflon tube

    Science.gov (United States)

    Watanabe, Yoshimi; Hotta, Takehiro; Sato, Hisashi

    2010-09-01

    In our previous paper, it was found that cotton yarn/TiO2-dispersed resin photonic crystals were fabricated successfully by applying textile technology. However, it is difficult to apply for practical use because these photonic crystals cannot change their shape flexibly. In this study, we fabricate the flexible photonic crystals using high-dielectric constant fibers. The high-dielectric constant fibers were made by inserting alumina balls into Teflon tubes. The crossed linear-fiber laminated fabric and multilayered woven fabric with an fcc lattice structure were structured by aligning high-dielectric constant fibers periodically. These photonic crystals consist of air and high-dielectric constant fibers. The attenuation of transmission amplitude through the photonic crystals was measured. The photonic crystal of crossed linear-fiber laminated fabric exhibits a forbidden gap in the range from 16 to 18 GHz range. On the other hand, the photonic crystal of multilayered woven fabric, which was fabricated by the same parameter with crossed linear-fiber laminated fabric, also exhibits a forbidden gap in the range from 13 to 16 GHz range. Thus, we can successfully fabricate flexible photonic crystals of woven fabric using high-dielectric constant fibers.

  9. Crystal Structure and Hydrogen Storage Behaviors of Mg/MoS2 Composites from Ball Milling

    Institute of Scientific and Technical Information of China (English)

    HAN Zongying; ZHOU Shixue; WANG Naifei; ZHANG Qianqian; ZHANG Tonghuan; RAN Weixian

    2016-01-01

    The Mg/MoS2 composites were prepared by ball milling under argon atmosphere, and the effect of MoS2 on the crystal structure and hydrogen storage properties of Mg was investigated. It is found that 10 wt% of MoS2 is sufifcient to prevent particle aggregation and cold welding during the milling process. The crystallite size of Mg will remain constant at slightly less than 38.8 nm with the milling process due to the size conifnement effect of MoS2. The dehydrogenation temperature of MgH2 is reduced to 390.4-429.4℃ due to the crystallite size reduction. Through iftting by Johnson-Mehl-Avrami model, it is found that Mg crystal grows by three dimension controlled by interface transformation during the process of MgH2 decomposition. MoS2 has a weak catalyst effect on the decomposition of MgH2 and activation energy of 148.9 kJ/mol is needed for the dehydrogenation process calculated by the Arrhenius equation.

  10. Bismuth-ceramic nanocomposites through ball milling and liquid crystal synthetic methods

    Science.gov (United States)

    Dellinger, Timothy Michael

    Three methods were developed for the synthesis of bismuth-ceramic nanocomposites, which are of interest due to possible use as thermoelectric materials. In the first synthetic method, high energy ball milling of bismuth metal with either MgO or SiO2 was found to produce nanostructured bismuth dispersed on a ceramic material. The morphology of the resulting bismuth depended on its wetting behavior with respect to the ceramic: the metal wet the MgO, but did not wet on the SiO2. Differential Scanning Calorimetry measurements on these composites revealed unusual thermal stability, with nanostructure retained after multiple cycles of heating and cooling through the metal's melting point. The second synthesis methodology was based on the use of lyotropic liquid crystals. These mixtures of water and amphiphilic molecules self-assemble to form periodic structures with nanometer-scale hydrophilic and hydrophobic domains. A novel shear mixing methodology was developed for bringing together reactants which were added to the liquid crystals as dissolved salts. The liquid crystals served to mediate synthesis by acting as nanoreactors to confine chemical reactions within the nanoscale domains of the mesophase, and resulted in the production of nanoparticles. By synthesizing lead sulfide (PbS) and bismuth (Bi) particles as proof-of-concept, it was shown that nanoparticle size could be controlled by controlling the dimensionality of the nanoreactors through control of the liquid crystalline phase. Particle size was shown to decrease upon going from three-dimensionally percolating nanoreactors, to two dimensional sheet-like nanoreactors, to one dimensional rod-like nanoreactors. Additionally, particle size could be controlled by varying the precursor salt concentration. Since the nanoparticles did not agglomerate in the liquid crystal immediately after synthesis, bismuth-ceramic nanocomposites could be prepared by synthesizing Bi nanoparticles and mixing in SiO2 particles which

  11. Gazing into the crystal ball: future considerations for ensuring sustained growth of the functional food and nutraceutical marketplace.

    Science.gov (United States)

    Marinangeli, Christopher P F; Jones, Peter J H

    2013-06-01

    Over the last decade the concept of functional foods and nutraceuticals (FFN) has gained support from various stakeholders including the food industry, scientific and academic community, government institutions or regulators, producers and consumers. However, as one begins to evaluate the global FFN industry, several issues emerge including (i) a lack of consensus across jurisdictions for acknowledging safe and efficacious FFN, (ii) challenges regarding the classification of novel food-derived bioactives as FFN or drugs, and (iii) a disconnect between nutrient requirements and dosages of FFN required to facilitate health benefits. The objectives of the present review are to discuss the role of existing stakeholders within the FFN marketplace and identify performance indicators for growth within the FFN sector. In addition, the following report provides feasible resolutions to present and future challenges facing the global FFN industry to ensure sustained long-term growth.

  12. Flavor Symmetry Studies with New Hyperon Data from the Crystal Ball

    Science.gov (United States)

    Nefkens, B. M. K.; Berger, E.; McDonald, S.; Phaisangittisakul, N.; Prakhov, S.; Price, J. W.; Starostin, A.; Tippens, W. B.

    2001-08-01

    New hyperon data produced in the reactions K-p → neutrals have been measured using the Crystal Ball 4π multiphoton spectrometer. They provide striking evidence for the important role of flavor symmetry in QCD at low energy. We will show that the pronounced features seen in π-p → ηn near threshold are also exhibited in K-p → ηΛ. The unique features of the π-p →π0π0n Dalitz plot are replicated in the flavor-symmetric reaction K-p → π0π0Λ, while K-p → π0π0Σ0, which is not flavor-related, is much different. The measured mass, width, and spin/parity of the Λ* octet hyperons are found to be the flavor symmetric copy of the N* states. Flavor symmetry combined with the narrowness of Ξ* states implies that searching for the missing baryon states may be done more profitably in the Ξ* family rather than in the N* or Δ* family.

  13. Assessing Self-Awareness through Gaze Agency.

    Science.gov (United States)

    Gregori Grgič, Regina; Crespi, Sofia Allegra; de'Sperati, Claudio

    2016-01-01

    We define gaze agency as the awareness of the causal effect of one's own eye movements in gaze-contingent environments, which might soon become a widespread reality with the diffusion of gaze-operated devices. Here we propose a method for measuring gaze agency based on self-monitoring propensity and sensitivity. In one task, naïf observers watched bouncing balls on a computer monitor with the goal of discovering the cause of concurrently presented beeps, which were generated in real-time by their saccades or by other events (Discovery Task). We manipulated observers' self-awareness by pre-exposing them to a condition in which beeps depended on gaze direction or by focusing their attention to their own eyes. These manipulations increased propensity to agency discovery. In a second task, which served to monitor agency sensitivity at the sensori-motor level, observers were explicitly asked to detect gaze agency (Detection Task). Both tasks turned out to be well suited to measure both increases and decreases of gaze agency. We did not find evident oculomotor correlates of agency discovery or detection. A strength of our approach is that it probes self-monitoring propensity-difficult to evaluate with traditional tasks based on bodily agency. In addition to putting a lens on this novel cognitive function, measuring gaze agency could reveal subtle self-awareness deficits in pathological conditions and during development.

  14. Measurement of the g p -> K^0 Sigma^+ reaction with the Crystal Ball/TAPS detectors at the Mainz Microtron

    CERN Document Server

    Aguar-Bartolomé, P; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Berghäuser, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil'kov, L V; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Isaksson, L; Jaegle, I; Jahn, O; Jude, T C; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nefkens, B M K; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Pheron, F; Polonski, A; Prakhov, S; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Sober, D I; Starostin, A; Strakovsky, I I; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmüller, D; Witthauer, L; Zehr, F

    2013-01-01

    The g p -> K^0 Sigma^+ reaction has been measured from threshold to Eg=1.45~GeV (W_cm=1.9~GeV) using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. In the present experiment, this reaction was searched for in the 3pi^0 p final state, assuming K^0_S -> pi^0 pi^0 and Sigma^+ -> pi^0 p. The experimental results include total and differential cross sections as well as the polarization of the recoil hyperon. The new data significantly improve the empirical knowledge about the g p -> K^0 Sigma^+ reaction in the measured energy range. The results are compared to previous measurements and model predictions. It was demonstrated that adding the present g p -> K^0 Sigma^+ results to existing data allowed a better description of this reaction with various models.

  15. Isospin Selectivity in Baryon and Hyperon Spectroscopy by Detecting Neutral Particle Final States with the Crystal Ball

    Science.gov (United States)

    Sadler, M. E.; Isenhower, L. D.; Spinka, H.; Comfort, J.; Clajus, M.; McDonald, S.; Moriwaki, T.; Nefkens, B. M. K.; Tippens, W. B.; Peterson, J.; Briscoe, W. J.; Papandreou, Z.; Efendiev, A.; Manley, D. M.; Abaev, V.; Bekrenev, V.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Starostin, A.; Batinic, M.; Marusic, A.; Slaus, I.; Supek, I.; Svarc, A.; Koetke, D.

    1996-05-01

    A comprehensive experimental program has recently been approved at the AGS at Brookhaven National Laboratory to measure absolute differential cross sections for π^- p and K^- p → neutrals in the momentum region 0.4 - 1.9 GeV/c. The SLAC Crystal Ball will be used as a multiphoton spectrometer to identify the various reaction channels by reconstructing the invariant mass of the γ rays produced from the decay of neutral mesons. The motivation for these measurements is to improve our understanding of the spectroscopy of baryons and hyperons. The isospin selectivity (e.g., for the reactions π^- p → η n and K^- p → π^o Λ) in populating certain resonances will be discussed.

  16. Determination of the Dalitz plot parameter alpha for the decay eta->3pi^0 with the Crystal Ball at MAMI-B

    CERN Document Server

    Unverzagt, M; Ahrens, J; Annand, J R M; Arends, H J; Beck, R; Bekrenev, V; Boillat, B; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J W; Cherepnya, S; Codling, R; Downie, E J; Filkov, L V; Glazier, D I; Gregor, R; Heid, E; Hornidge, D; Jahn, O; Kashevarov, V L; Kondratiev, R; Korolija, M; Kotulla, M; Krambrich, D; Krusche, B; Lang, M; Lisin, V; Livingston, K; Lugert, S; MacGregor, I J D; Manley, D M; Martinez-Fabregate, M; McGeorge, J C; Mekterovic, D; Metag, V; Nefkens, B M K; Nikolaev, A; Novotny, R; Owens, R O; Pedroni, P; Polonski, A; Prakhov, S N; Price, J W; Rosner, G; Rost, M; Rostomyan, T; Schumann, S; Sober, D; Starostin, A; Supek, I; Tarbert, C M; Thomas, A; Walcher, Th; Watts, D P; Zehr, F

    2008-01-01

    A precise measurement of the Dalitz plot parameter, alpha, for the eta->3pi^0 decay is presented. The experiment was performed with the Crystal Ball and TAPS large acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8*10^6 eta->3pi^0 events were obtained, giving the result alpha = -0.032 \\pm 0.002_{stat} \\pm 0.002_{syst}.

  17. Aplicación de la simulación Monte Carlo en la administración de proyectos utilizando Excel y @Crystal Ball (ING

    Directory of Open Access Journals (Sweden)

    Carlos Azofeifa

    2016-03-01

    Full Text Available Simulation Monte Carlo is an effective technique used to analyze the critical path in a project, this simulation will be used to estimate the probability of finishing the project on time. Monte Carlo is necessary due to the hight uncertainty showed in the estimations of time operations from the differents activities in the project. For facility the calculations, @Crystal Ball software is a popular spreadsheet add-in used for simulations and risk analysis.

  18. Ubiquitous gaze: using gaze at the interface

    NARCIS (Netherlands)

    Heylen, Dirk; Aghajan, Hamid; López-Cózar Delgado, Ramón; Augusto, Juan Carlos

    2010-01-01

    In the quest for more natural forms of interaction between humans and machines, information on where someone is looking and how (for how long, with long or shorter gaze periods) plays a prominent part. The importance of gaze in social interaction, its manifold functions and expressive force, and the

  19. Keeping your eyes continuously on the ball while running for catchable and uncatchable fly balls.

    Directory of Open Access Journals (Sweden)

    Dees B W Postma

    Full Text Available When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its initial conditions. Alternatively, such predictive information is not available, and running to the interception location involves continuous visual guidance. The latter type of control would predict that fielders keep looking at the approaching ball for most of its flight, whereas the former type of control would fit with looking at the ball during the early part of the ball's flight; keeping the eyes on the ball during the remainder of its trajectory would not be necessary when the interception location can be inferred from the first part of the ball trajectory. The present contribution studied visual tracking of approaching fly balls. Participants were equipped with a mobile eye tracker. They were confronted with tennis balls approaching from about 20 m, and projected in such a way that some balls were catchable and others were not. In all situations, participants almost exclusively tracked the ball with their gaze until just before the catch or until they indicated that a ball was uncatchable. This continuous tracking of the ball, even when running close to their maximum speeds, suggests that participants employed continuous visual control rather than running to an interception location known from looking at the early part of the ball flight.

  20. New Tests of Chiral Perturbation Theory in η Decays Using the Crystal Ball

    Science.gov (United States)

    Nefkens, B. M. K.; Prakhov, S.; Berger, E.; Clajus, M.; Marušić, A.; McDonald, S.; Nefkens, B. M. K.; Phaisangittisakul, N.; Prakhov, S.; Pulver, M.; Starostin, A.; Tippens, W. B.; Isenhower, D.; Sadler, M.; Allgower, C.; Spinka, H.; Comfort, J.; Craig, K.; Ramirez, T.; Kycia, T.; Peterson, J.; Briscoe, W.; Shafi, A.; Staudenmaier, H. M.; Manley, D. M.; Olmsted, J.; Peaslee, D.; Bekrenev, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Huber, G. M.; Knecht, N.; Lolos, G. J.; Papandreou, Z.; Slaus, I.; Supek, I.; Grosnick, D.; Koetke, D.; Manweiler, R.; Stanislaus, S.

    2001-12-01

    The G-parity violating η → 3π0 decay occurs primarily as a consequence of the up-down quark mass difference, mu - md. In the standard notation 1 A(η → 3π0) (mu - md)(1 + αz) and Γ(η → 3π0) (mu - md)2(1 + 2αz), where α is the quadratic slope parameter, z = (ρ /ρ max } )2 \\ ∑ {(Ei{π o } - mη /3)2 } , ρ is the distance from the center of the Dalitz plot. Thus far χPTh has not succeeded in accounting fully for the experimental η → 3π decay rate. The expanded {O}(p4 ) calculation which includes pion-pion rescattering to all orders 2 is still too low by (34 ± 10)%. It has been suggested 3 that this might be due to dynamical effects with terms {O}(p6 ) such as {L}6 \\ Fπ 2 trmDμ UDμ U\\dag trDν UDν U\\dag . This possibility may be explored by a precise measurement of the quadratic slope parameter α in η → 3π0 decay. The existing data are inconclusive. GAMS-2000 4 obtained α = -(22±23) × 10-3. The Crystal Barrel 5 has reported α = -(52±15±10) × 10-3. The theoretical prediction 2 is α = -(14 to 7) × 10-3 ...

  1. Ball clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    The article reports on the global market performance of ball clay in 2009 and presents an outlook for its 2010 performance. Several companies mined ball call in the country including Old Hickey Clay Co., Kentucky-Tennessee Clay Co., and H.C. Spinks Clay Co. Information on the decline in ball clay imports and exports is also presented.

  2. Perceptual elements in Penn & Teller's "Cups and Balls" magic trick.

    Science.gov (United States)

    Rieiro, Hector; Martinez-Conde, Susana; Macknik, Stephen L

    2013-01-01

    Magic illusions provide the perceptual and cognitive scientist with a toolbox of experimental manipulations and testable hypotheses about the building blocks of conscious experience. Here we studied several sleight-of-hand manipulations in the performance of the classic "Cups and Balls" magic trick (where balls appear and disappear inside upside-down opaque cups). We examined a version inspired by the entertainment duo Penn & Teller, conducted with three opaque and subsequently with three transparent cups. Magician Teller used his right hand to load (i.e. introduce surreptitiously) a small ball inside each of two upside-down cups, one at a time, while using his left hand to remove a different ball from the upside-down bottom of the cup. The sleight at the third cup involved one of six manipulations: (a) standard maneuver, (b) standard maneuver without a third ball, (c) ball placed on the table, (d) ball lifted, (e) ball dropped to the floor, and (f) ball stuck to the cup. Seven subjects watched the videos of the performances while reporting, via button press, whenever balls were removed from the cups/table (button "1") or placed inside the cups/on the table (button "2"). Subjects' perception was more accurate with transparent than with opaque cups. Perceptual performance was worse for the conditions where the ball was placed on the table, or stuck to the cup, than for the standard maneuver. The condition in which the ball was lifted displaced the subjects' gaze position the most, whereas the condition in which there was no ball caused the smallest gaze displacement. Training improved the subjects' perceptual performance. Occlusion of the magician's face did not affect the subjects' perception, suggesting that gaze misdirection does not play a strong role in the Cups and Balls illusion. Our results have implications for how to optimize the performance of this classic magic trick, and for the types of hand and object motion that maximize magic misdirection.

  3. Gaze beats mouse

    DEFF Research Database (Denmark)

    Mateo, Julio C.; San Agustin, Javier; Hansen, John Paulin

    2008-01-01

    Facial EMG for selection is fast, easy and, combined with gaze pointing, it can provide completely hands-free interaction. In this pilot study, 5 participants performed a simple point-and-select task using mouse or gaze for pointing and a mouse button or a facial-EMG switch for selection. Gaze...... pointing was faster than mouse pointing, while maintaining a similar error rate. EMG and mouse-button selection had a comparable performance. From analyses of completion time, throughput and error rates, we concluded that the combination of gaze and facial EMG holds potential for outperforming the mouse....

  4. Gaze Tracking Through Smartphones

    DEFF Research Database (Denmark)

    Skovsgaard, Henrik; Hansen, John Paulin; Møllenbach, Emilie

    Mobile gaze trackers embedded in smartphones or tablets provide a powerful personal link to game devices, head-mounted micro-displays, pc´s, and TV’s. This link may offer a main road to the mass market for gaze interaction, we suggest.......Mobile gaze trackers embedded in smartphones or tablets provide a powerful personal link to game devices, head-mounted micro-displays, pc´s, and TV’s. This link may offer a main road to the mass market for gaze interaction, we suggest....

  5. Determination of the Dalitz plot parameter {alpha} for the decay {eta}{yields}3{pi}{sup 0} with the Crystal Ball at MAMI-B

    Energy Technology Data Exchange (ETDEWEB)

    Unverzagt, M.; Beck, R.; Lang, M.; Nikolaev, A.; Schumann, S. [University Mainz, Institut fuer Kernphysik, Mainz (Germany); University Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Aguar-Bartolome, P.; Ahrens, J.; Arends, H.J.; Heid, E.; Jahn, O.; Krambrich, D.; Martinez-Fabregate, M.; Rost, M.; Thomas, A.; Walcher, T. [University Mainz, Institut fuer Kernphysik, Mainz (Germany); Annand, J.R.M.; Codling, R.; Livingston, K.; MacGregor, I.J.D.; McGeorge, J.C.; Owens, R.O.; Rosner, G. [University of Glasgow, Department of Physics and Astronomy, Glasgow (United Kingdom); Bekrenev, V. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Boillat, B.; Krusche, B.; Zehr, F. [University Basel, Institut fuer Physik, Basel (Switzerland); Braghieri, A.; Pedroni, P.; Rostomyan, T. [INFN Sezione di Pavia, Pavia (Italy); Branford, D.; Glazier, D.I.; Tarbert, C.M.; Watts, D.P. [Univ. of Edinburgh, School of Physics, Edinburgh (United Kingdom); Briscoe, W.J. [The George Washington Univ., Center for Nuclear Studies, Washington, D.C. (United States); Brudvik, J.W.; Nefkens, B.M.K.; Prakhov, S.N.; Price, J.W.; Starostin, A. [Univ. of California at Los Angeles, Los Angeles, CA (United States); Cherepnya, S.; Fil' kov, L.V.; Kashevarov, V.L. [Lebedev Physical Inst., Moscow (Russian Federation); Downie, E.J. [Univ. Mainz, Inst. fuer Kernphysik, Mainz (Germany); Univ. of Glasgow, Dept. of Physics and Astronomy, Glasgow (United Kingdom); Gregor, R.; Kotulla, M.; Lugert, S.; Metag, V.; Novotny, R. [Univ. Giessen, II. Physikalisches Inst., Giessen (Germany); Hornidge, D. [Mount Allison Univ., Sackville, NB (Canada); Kondratiev, R.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Korolija, M.; Mekterovic, D.; Supek, I. [Rudjer Boskovic Inst., Zagreb (Croatia); Manley, D.M. [Kent State Univ., Kent, OH (United States); Sober, D. [The Catholic Univ. of America, Washington, D.C. (United States)

    2009-02-15

    A precise measurement of the Dalitz plot parameter, {alpha}, for the {eta}{yields}3{pi}{sup 0} decay is presented. The experiment was performed with the Crystal Ball and TAPS large-acceptance photon detectors at the tagged photon beam facility of the MAMI-B electron accelerator in Mainz. High statistics of 1.8.10{sup 6} {eta}{yields}3{pi}{sup 0} events were obtained, giving the result {alpha}=-0.032{+-}0.002{sub stat}{+-}0.002{sub syst}. (orig.)

  6. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global ball clay mining industry, particularly in the U.S., as of June 2011. It cites several firms that are involved in ball clay mining in the U.S., including HC Spins Clay Co. Inc., the Imerys Group and Old Hickory Clay Co. Among the products made from ball clay are ceramic tiles, sanitaryware, as well as fillers, extenders and binders.

  7. Gaze interaction from bed

    DEFF Research Database (Denmark)

    Hansen, John Paulin; San Agustin, Javier; Jensen, Henrik Tomra Skovsgaard Hegner

    2011-01-01

    This paper presents a low-cost gaze tracking solution for bedbound people composed of free-ware tracking software and commodity hardware. Gaze interaction is done on a large wall-projected image, visible to all people present in the room. The hardware equipment leaves physical space free to assist...

  8. Gazes and Performances

    DEFF Research Database (Denmark)

    Larsen, Jonas

    Abstract: Recent literature has critiqued this notion of the 'tourist gaze' for reducing tourism to visual experiences 'sightseeing' and neglecting other senses and bodily experiences of doing tourism. A so-called 'performance turn' within tourist studies highlights how tourists experience places...... revised and expanded Tourist Gaze 3.0 that I am writing with John Urry at the moment....

  9. Using Latex Balls and Acrylic Resin Plates to Investigate the Stacking Arrangement and Packing Efficiency of Metal Crystals

    Science.gov (United States)

    Ohashi, Atsushi

    2015-01-01

    A high-school third-year or undergraduate first-semester general chemistry laboratory experiment introducing simple-cubic, face-centered cubic, body-centered cubic, and hexagonal closest packing unit cells is presented. Latex balls and acrylic resin plates are employed to make each atomic arrangement. The volume of the vacant space in each cell is…

  10. Single gaze gestures

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Lilholm, Martin; Gail, Alastair

    2010-01-01

    This paper examines gaze gestures and their applicability as a generic selection method for gaze-only controlled interfaces. The method explored here is the Single Gaze Gesture (SGG), i.e. gestures consisting of a single point-to-point eye movement. Horizontal and vertical, long and short SGGs we...... evaluated on two eye tracking devices (Tobii/QuickGlance (QG)). The main findings show that there is a significant difference in selection times between long and short SGGs, between vertical and horizontal selections, as well as between the different tracking systems....

  11. Gazing and Performing

    DEFF Research Database (Denmark)

    Larsen, Jonas; Urry, John

    2011-01-01

    The Tourist Gaze [Urry J, 1990 (Sage, London)] is one of the most discussed and cited tourism books (with about 4000 citations on Google scholar). Whilst wide ranging in scope, the book is known for the Foucault-inspired concept of the tourist gaze that brings out the fundamentally visual and image...... that the doings of tourism are physical or corporeal and not merely visual, and it is necessary to regard ‘performing’ rather than ‘gazing’ as the dominant tourist research paradigm. Yet we argue here that there are, in fact, many similarities between the paradigms of gaze and of performance. They should ‘dance...

  12. Non-isothermal crystallization kinetics of polyethylene–clay nanocomposites prepared by high-energy ball milling

    Indian Academy of Sciences (India)

    Maryam Abareshi; Seyed Mojtaba Zebarjad; Elaheh K Goharshadi

    2014-08-01

    Non-isothermal crystallization kinetics of pure medium density polyethylene (MDPE) and MDPE–clay nanocomposites have been investigated by differential scanning calorimeter. The modified Avrami, Ozawa, Liu and Ziabicki equations have been applied to describe non-isothermal crystallization process. The results of Avrami analysis showed a very complicated crystallization mechanism. Although, Ozawa equation failed to provide an adequate description for non-isothermal crystallization process, Liu equation could describe it well. The data showed the crystallization rate of MDPE and nanocomposites raises with increasing cooling rate and the crystallization rate of nanocomposite is faster than that of MDPE at a given cooling rate. Ziabicki’s kinetic crystallizability index showed that clay can increase the ability of MDPE to crystallize, when it is cooled at unit cooling rate. The activation energy of samples has been evaluated by Kissinger method. The results showed that the activation energy of nanocomposite was lower than that of MDPE.

  13. Gaze as a biometric

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hong-Jun [ORNL; Carmichael, Tandy [Tennessee Technological University; Tourassi, Georgia [ORNL

    2014-01-01

    Two people may analyze a visual scene in two completely different ways. Our study sought to determine whether human gaze may be used to establish the identity of an individual. To accomplish this objective we investigated the gaze pattern of twelve individuals viewing different still images with different spatial relationships. Specifically, we created 5 visual dot-pattern tests to be shown on a standard computer monitor. These tests challenged the viewer s capacity to distinguish proximity, alignment, and perceptual organization. Each test included 50 images of varying difficulty (total of 250 images). Eye-tracking data were collected from each individual while taking the tests. The eye-tracking data were converted into gaze velocities and analyzed with Hidden Markov Models to develop personalized gaze profiles. Using leave-one-out cross-validation, we observed that these personalized profiles could differentiate among the 12 users with classification accuracy ranging between 53% and 76%, depending on the test. This was statistically significantly better than random guessing (i.e., 8.3% or 1 out of 12). Classification accuracy was higher for the tests where the users average gaze velocity per case was lower. The study findings support the feasibility of using gaze as a biometric or personalized biomarker. These findings could have implications in Radiology training and the development of personalized e-learning environments.

  14. Measurement of the Slope Parameter $\\alpha$ for the $\\eta\\to 3\\pi^0$ decay with the Crystal Ball at MAMI-C

    CERN Document Server

    Prakhov, S; Aguar, P; Akasoy, L K; Annand, J R M; Arends, H J; Bartolome, P A; Bantawa, K; Beck, R; Bekrenev, V; Berghauser, H; Boillat, B; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Downie, E J; Drexler, P; Filkov, L V; Glazier, D I; Gregor, R; Heid, E; Hornidge, D; Jahn, O; Jude, T C; Kashevarov, V L; Kellie, J D; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Krambrich, D; Kruglov, S; Krusche, B; Lang, M; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Manley, D M; Martínez, M; McGeorge, J C; McNicoll, E F; Mekterovic, D; Metag, V; Micanovic, S; Nikolaev, A; Novotny, R; Ostrick, M; Otte, P B; Pedroni, P; Pheron, F; Polonski, A; Robinson, J; Rosner, G; Rost, M; Rostomyan, T; Schumann, S; Sikora, M H; Sober, D I; Starostin, A; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Zamboni, I; Zehr, F

    2008-01-01

    The dynamics of the $\\eta\\to 3\\pi^0$ decay have been studied with the Crystal Ball multiphoton spectrometer and the TAPS calorimeter. Bremsstrahlung photons produced by the 1.5 GeV electron beam of the Mainz microtron MAMI-C and tagged by the Glasgow photon spectrometer were used for $\\eta$-meson production. The analysis of $3 \\times 10^6$ $\\gamma p \\to \\eta p \\to 3\\pi^0 p \\to 6\\gamma p$ events yields the value $\\alpha=-0.032\\pm0.003$ for the $\\eta\\to 3\\pi^0$ slope parameter, which agrees with the majority of recent experimental results and has the smallest uncertainty. The $\\pi^0\\pi^0$ invariant-mass spectrum was investigated for the occurrence of a cusp-like structure in the vicinity of the $\\pi^+\\pi^-$ threshold. The observed effect is small and does not affect our measured value for the slope parameter.

  15. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    Energy Technology Data Exchange (ETDEWEB)

    Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P; Annand, J R; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Bergh��user, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil' kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; K��ser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmueller, D; Witthauer, L

    2014-08-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  16. A new determination of the eta transition form factor in the Dalitz decay eta -> e^+ e^- gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    CERN Document Server

    Aguar-Bartolomé, P; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Berghäuser, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Collicott, C; Denig, A; Downie, E J; Drexler, P; Fil'kov, L V; Fix, A; Glazier, D I; Gregor, R; Hamilton, D J; Heid, E; Hornidge, D; Isaksson, L; Jaegle, I; Jahn, O; Jude, T C; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Manley, D M; McGeorge, J C; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nefkens, B M K; Nikolaev, A; Novotny, R; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Pheron, F; Polonski, A; Prakhov, S; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Sober, D I; Starostin, A; Strakovsky, I I; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmüller, D; Zehr., F

    2013-01-01

    The Dalitz decay eta -> e^+ e^- gamma has been measured in the gamma p -> eta p reaction with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. The experimental statistic used in this work is one order of magnitude greater than in any previous measurement of eta -> e^+ e^- gamma. The value obtained for the slope parameter 1/Lambda^2 of the eta transition form factor, 1/Lambda^2 = (1.95 +/- 0.15_stat +/- 0.10_syst) [1/GeV^2], is in good agreement with recent measurements conducted in eta -> e^+ e^- gamma and eta -> mu^+ mu^- gamma decays as well as with recent form-factor calculations. The uncertainty obtained in the value of 1/Lambda^2 is lower compared to results from previous measurements of the eta -> e^+ e^- gamma decay.

  17. A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

    CERN Document Server

    Nefkens, B M K; Aguar-Bartolomé, P; Annand, J R M; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Berghäuser, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil'kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; Käser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmüller, D; Witthauer., L

    2014-01-01

    A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

  18. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements: fix...

  19. The Epistemology of the Gaze

    DEFF Research Database (Denmark)

    Kramer, Mette

    2007-01-01

    In psycho-semiotic film theory the gaze is often considered to be a straitjacket for the female spectator. If we approach the gaze from an empiric so-called ‘naturalised’ lens, it is possible to regard the gaze as a functional devise through which the spectator can obtain knowledge essential for ...

  20. A GazeWatch Prototype

    DEFF Research Database (Denmark)

    Paulin Hansen, John; Biermann, Florian; Møllenbach, Emile

    2015-01-01

    We demonstrate potentials of adding a gaze tracking unit to a smartwatch, allowing hands-free interaction with the watch itself and control of the environment. Users give commands via gaze gestures, i.e. looking away and back to the GazeWatch. Rapid presentation of single words on the watch displ...

  1. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements...

  2. Construction of the Crystal Ball detector system and study of the helicity asymmetry in {gamma}p{yields}p{pi}{sup 0}{pi}{sup 0}; Aufbau des Crystal Ball-Detektorsystems und Untersuchung der Helizitaetsasymmetrie in {gamma} p {yields} p {pi}{sup 0} {pi}{sup 0}

    Energy Technology Data Exchange (ETDEWEB)

    Krambrich, D.

    2007-01-15

    Since spring 2004 the Crystal Ball Detector has been used for coincidence experiments probing the structure of the nucleons with real photons at the Mainzer Microtron. A major part of the commissioning, which was the first goal of this work, was the development and implementation of a new system for the Crystal Ball electronics. Components were designed or tested and, if necessary, modified to fit the experimental needs. After the commissioning, the set-up was then used successfully in several pion and eta production experiments for more than 2500 hours of beamtime. The second focus of this dissertation is the first measurement of the beam helicity asymmetry I{sup s}un in photoproduction of two neutral pions. The understanding of the excitation spectra of the nucleon requires experiments using polarised photons and/or polarised targets. Models based on different assumptions do reproduce the quantities measured without polarisation equally well but differ in the prediction of polarisation observables. The determination of more sensitive quantities is therefore mandatory. In contrast to single meson production, an observable appears in double pion production when using circularly polarized photons incident on an unpolarized target. This observable was determined as a function of energy and angle in the reactions {gamma} p {yields} p {pi}{sup 0} {pi}{sup 0} and in {gamma} p {yields} p {pi}{sup +} {pi}{sup -}. The results differ significantly from the model predictions. (orig.)

  3. Science of Ball Lightning (Fire Ball)

    Science.gov (United States)

    Ohtsuki, Yoshi-Hiko

    1989-08-01

    The Table of Contents for the full book PDF is as follows: * Organizing Committee * Preface * Ball Lightning -- The Continuing Challenge * Hungarian Ball Lightning Observations in 1987 * Nature of Ball Lightning in Japan * Phenomenological and Psychological Analysis of 150 Austrian Ball Lightning Reports * Physical Problems and Physical Properties of Ball Lightning * Statistical Analysis of the Ball Lightning Properties * A Fluid-Dynamical Model for Ball Lightning and Bead Lightning * The Lifetime of Hill's Vortex * Electrical and Radiative Properties of Ball Lightning * The Candle Flame as a Model of Ball Lightning * A Model for Ball Lightning * The High-Temperature Physico-Chemical Processes in the Lightning Storm Atmosphere (A Physico-Chemical Model of Ball Lightning) * New Approach to Ball Lightning * A Calculation of Electric Field of Ball Lightning * The Physical Explanation to the UFO over Xinjiang, Northern West China * Electric Reconnection, Critical Ionization Velocity, Ponderomotive Force, and Their Applications to Triggered and Ball Lightning * The PLASMAK™ Configuration and Ball Lightning * Experimental Research on Ball Lightning * Performance of High-Voltage Test Facility Designed for Investigation of Ball Lightning * List of Participants

  4. Gaze Interactive Building Instructions

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Ahmed, Zaheer; Mardanbeigi, Diako

    We combine eye tracking technology and mobile tablets to support hands-free interaction with digital building instructions. As a proof-of-concept we have developed a small interactive 3D environment where one can interact with digital blocks by gaze, keystroke and head gestures. Blocks may be moved...

  5. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  6. Gaze shifts and fixations dominate gaze behavior of walking cats

    Science.gov (United States)

    Rivers, Trevor J.; Sirota, Mikhail G.; Guttentag, Andrew I.; Ogorodnikov, Dmitri A.; Shah, Neet A.; Beloozerova, Irina N.

    2014-01-01

    Vision is important for locomotion in complex environments. How it is used to guide stepping is not well understood. We used an eye search coil technique combined with an active marker-based head recording system to characterize the gaze patterns of cats walking over terrains of different complexity: (1) on a flat surface in the dark when no visual information was available, (2) on the flat surface in light when visual information was available but not required, (3) along the highly structured but regular and familiar surface of a horizontal ladder, a task for which visual guidance of stepping was required, and (4) along a pathway cluttered with many small stones, an irregularly structured surface that was new each day. Three cats walked in a 2.5 m corridor, and 958 passages were analyzed. Gaze activity during the time when the gaze was directed at the walking surface was subdivided into four behaviors based on speed of gaze movement along the surface: gaze shift (fast movement), gaze fixation (no movement), constant gaze (movement at the body’s speed), and slow gaze (the remainder). We found that gaze shifts and fixations dominated the cats’ gaze behavior during all locomotor tasks, jointly occupying 62–84% of the time when the gaze was directed at the surface. As visual complexity of the surface and demand on visual guidance of stepping increased, cats spent more time looking at the surface, looked closer to them, and switched between gaze behaviors more often. During both visually guided locomotor tasks, gaze behaviors predominantly followed a repeated cycle of forward gaze shift followed by fixation. We call this behavior “gaze stepping”. Each gaze shift took gaze to a site approximately 75–80 cm in front of the cat, which the cat reached in 0.7–1.2 s and 1.1–1.6 strides. Constant gaze occupied only 5–21% of the time cats spent looking at the walking surface. PMID:24973656

  7. Nanocrystalline Nd{sub 2}Fe{sub 17} synthesized by high-energy ball milling: crystal structure, microstructure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Pablo; Gorria, Pedro; Perez, Maria J; Sanchez Llamazares, Jose L; Blanco, Jesus A [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Franco, Victorino [Departamento Fisica de la Materia Condensada, ICMSE-CSIC, Universidad de Sevilla, PO Box 1065, 41080 Sevilla (Spain); Sanchez Marcos, Jorge [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain); Puente Orench, Ines, E-mail: alvarezpablo.uo@uniovi.e [Institute Laue-Langevin, BP 156, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

    2010-06-02

    Nanocrystalline Nd{sub 2}Fe{sub 17} powders have been obtained by means of high-energy ball milling from nearly single-phase bulk alloys produced by arc melting and high temperature homogenization annealing. The rhombohedral Th{sub 2}Zn{sub 17}-type crystal structure of the bulk alloy remains unaltered after the milling process, with almost unchanged values for the cell parameters. However, the severe mechanical processing induces drastic microstructural changes. A decrease of the mean crystalline size down to around 10 nm is observed, giving rise to a considerable augmentation of the disordered inter-grain boundaries. This modification of the microstructure affects the magnetic behaviour of the milled powders, although the magnetic structure remains collinear ferromagnetic. While a unique ferro-to-paramagnetic transition temperature, T{sub C} = 339 {+-} 2 K, is observed in the bulk alloy, the nanocrystalline samples exhibit a more likely distribution of T{sub C} values. The latter seems to be responsible for the significant broadening of the temperature range in which magneto-caloric effect is observed, and the lowering of the maximum value of the magnetic entropy change.

  8. EYE GAZE TRACKING

    DEFF Research Database (Denmark)

    2017-01-01

    This invention relates to a method of performing eye gaze tracking of at least one eye of a user, by determining the position of the center of the eye, said method comprising the steps of: detecting the position of at least three reflections on said eye, transforming said positions to spanning...... a normalized coordinate system spanning a frame of reference, wherein said transformation is performed based on a bilinear transformation or a non linear transformation e.g. a möbius transformation or a homographic transformation, detecting the position of said center of the eye relative to the position...... of said reflections and transforming this position to said normalized coordinate system, tracking the eye gaze by tracking the movement of said eye in said normalized coordinate system. Thereby calibration of a camera, such as knowledge of the exact position and zoom level of the camera, is avoided...

  9. Gaze Behaviour during Interception in Children with Spastic Unilateral Cerebral Palsy

    Science.gov (United States)

    van Kampen, P. M.; Ledebt, A.; Smorenburg, A. R. P.; Vermeulen, R. J.; Kelder, M. E.; van der Kamp, J.; Savelsbergh, G. J. P.

    2012-01-01

    Anticipatory gaze behaviour during interceptive movements was investigated in children with Spastic Unilateral Cerebral Palsy (SUCP), and related to the side of the intracerebral lesion. Five children with lesions of the right hemisphere (RHL) and five children with lesions of the left hemisphere (LHL) had to walk towards and intercept a ball that…

  10. Gaze Behaviour during Interception in Children with Spastic Unilateral Cerebral Palsy

    Science.gov (United States)

    van Kampen, P. M.; Ledebt, A.; Smorenburg, A. R. P.; Vermeulen, R. J.; Kelder, M. E.; van der Kamp, J.; Savelsbergh, G. J. P.

    2012-01-01

    Anticipatory gaze behaviour during interceptive movements was investigated in children with Spastic Unilateral Cerebral Palsy (SUCP), and related to the side of the intracerebral lesion. Five children with lesions of the right hemisphere (RHL) and five children with lesions of the left hemisphere (LHL) had to walk towards and intercept a ball that…

  11. Objects capture perceived gaze direction.

    Science.gov (United States)

    Lobmaier, Janek S; Fischer, Martin H; Schwaninger, Adrian

    2006-01-01

    The interpretation of another person's eye gaze is a key element of social cognition. Previous research has established that this ability develops early in life and is influenced by the person's head orientation, as well as local features of the person's eyes. Here we show that the presence of objects in the attended space also has an impact on gaze interpretation. Eleven normal adults identified the fixation points of photographed faces with a mouse cursor. Their responses were systematically biased toward the locations of nearby objects. This capture of perceived gaze direction probably reflects the attribution of intentionality and has methodological implications for research on gaze perception.

  12. Demo of Gaze Controlled Flying

    DEFF Research Database (Denmark)

    Alapetite, Alexandre; Hansen, John Paulin; Scott MacKenzie, I.

    2012-01-01

    Development of a control paradigm for unmanned aerial vehicles (UAV) is a new challenge to HCI. The demo explores how to use gaze as input for locomotion in 3D. A low-cost drone will be controlled by tracking user’s point of regard (gaze) on a live video stream from the UAV....

  13. Bouncing Balls that Spin

    Science.gov (United States)

    Knipp, Peter

    2008-01-01

    When a ball bounces elastically against a floor, the vertical component (v[subscript y]) of the velocity of the ball's mass-center changes sign. This is a special case of the elastic collision of two balls (i.e., two objects, neither of which is much more massive than the other), in which case the balls' post-collision relative velocity (=…

  14. Beyond the crystal ball assumption

    DEFF Research Database (Denmark)

    Vaucouleur, Sebastien

    2008-01-01

    trades control for flexibility. Unfortunately, it also makes the customized software product very sensitive to upgrades. We propose a more mitigated solution, that does not require accurate anticipation and yet offers some resilience to evolution of the base software product through the use of code...... quantification. We introduce the Eggther framework for customization of evolvable software products in general and ERP systems in particular. Our approach is based on the concept of code query by example. The technology being developed is based on an initial empirical study on practices around ERP systems. We...... motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the upgrade problem....

  15. Analysis of the Crystal Ball data on $K^-p\\to\\pi^0\\Sigma^0$ reaction with center-of-mass energies of $1536\\sim 1676$ MeV

    CERN Document Server

    Shi, Jun

    2014-01-01

    With an effective Lagrangian approach, we analyze the $K^-p\\to \\pi^0\\Sigma^0$ reaction to study the $\\Lambda$ hyperon resonances by fitting the Crystal Ball data on differential cross sections and $\\Sigma^0$ polarization with the center-of-mass energies of $1536\\sim 1676$ MeV. Besides well established PDG 4-star $\\Lambda$ resonances around this energy range, the $\\Lambda(1600){1\\over 2}^+$ resonance, listed as a 3-star resonance in PDG, is found to be definitely needed. In addition, there is strong evidence for the existence of a new $\\Lambda({3\\over 2}^+)$ resonance around 1680 MeV.

  16. Determination of the Dalitz-plot parameter {alpha} for the decay {eta}{yields}3{pi}{sup 0} with the Crystal Ball at MAMI; Bestimmung des Dalitz-Plot-Parameters {alpha} fuer den Zerfall {eta} {yields} 3{pi}{sup 0} mit dem Crystal Ball am MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Unverzagt, Marc

    2008-05-26

    In order to determine the Dalitz-plot parameter {alpha} experiments were evaluated, Which were performed with the Crystal Ball/TAPS facility at the accelerator MAMI of the Institute for Nuclear Physics at the Johannes Gutenberg University in Mainz in the years 2004 and 2005. {eta} mesons wer produced via the reaction {gamma}p{yields}{eta}p. From four different analyses the following four in this thesis determined Dalitz-plot parameters with the given statistics resulted: {eta} without proton: {alpha}=-0.0314{+-}0.0013{sub -0.0014}{sup +0.0017} (1.1.10{sup 6} events), {eta} with proton: {alpha}=-0.0338{+-}0.0020{sub -0.0022}{sup +0.0019} (4.2.10{sup 5} events), {delta}{sup +} magnetic dipole moment without proton: {alpha}=-0.0277{+-}0.0013{sub -0.0019}{sup +0.0014} (7.1.10{sup 5} events), {delta}{sup +} magnetic dipole moment with proton: {alpha}=-0.0272{+-}0.0019{sub -0.0043}{sup +0.0022} (3.1.10{sup 5} events).

  17. Gaze categorization under uncertainty: psychophysics and modeling.

    Science.gov (United States)

    Mareschal, Isabelle; Calder, Andrew J; Dadds, Mark R; Clifford, Colin W G

    2013-04-22

    The accurate perception of another person's gaze direction underlies most social interactions and provides important information about his or her future intentions. As a first step to measuring gaze perception, most experiments determine the range of gaze directions that observers judge as being direct: the cone of direct gaze. This measurement has revealed the flexibility of observers' perception of gaze and provides a useful benchmark against which to test clinical populations with abnormal gaze behavior. Here, we manipulated effective signal strength by adding noise to the eyes of synthetic face stimuli or removing face information. We sought to move beyond a descriptive account of gaze categorization by fitting a model to the data that relies on changing the uncertainty associated with an estimate of gaze direction as a function of the signal strength. This model accounts for all the data and provides useful insight into the visual processes underlying normal gaze perception.

  18. Having a Ball with Fitness Balls

    Science.gov (United States)

    McNulty, Betty

    2011-01-01

    Fitness programs can be greatly enhanced with the addition of fitness balls. They are a fun, challenging, economical, and safe way to incorporate a cardiovascular, strength, and stretching program for all fitness levels in a physical education setting. The use of these balls has become more popular during the last decade, and their benefits and…

  19. Ball Screw Actuator Including a Compliant Ball Screw Stop

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

    2017-01-01

    An actuator includes a ball nut, a ball screw, and a ball screw stop. The ball nut is adapted to receive an input torque and in response rotates and supplies a drive force. The ball screw extends through the ball nut and has a first end and a second end. The ball screw receives the drive force from the ball nut and in response selectively translates between a retract position and a extend position. The ball screw stop is mounted on the ball screw proximate the first end to translate therewith. The ball screw stop engages the ball nut when the ball screw is in the extend position, translates, with compliance, a predetermined distance toward the first end upon engaging the ball nut, and prevents further rotation of the ball screw upon translating the predetermined distance.

  20. Gaze disorders: A clinical approach

    Directory of Open Access Journals (Sweden)

    Pulikottil Wilson Vinny

    2016-01-01

    Full Text Available A single clear binocular vision is made possible by the nature through the oculomotor system along with inputs from the cortical areas as well their descending pathways to the brainstem. Six systems of supranuclear control mechanisms play a crucial role in this regard. These are the saccadic system, the smooth pursuit system, the vestibular system, the optokinetic system, the fixation system, and the vergence system. In gaze disorders, lesions at different levels of the brain spare some of the eye movement systems while affecting others. The resulting pattern of eye movements helps clinicians to localize lesions accurately in the central nervous system. Common lesions causing gaze palsies include cerebral infarcts, demyelinating lesions, multiple sclerosis, tumors, Wernicke's encephalopathy, metabolic disorders, and neurodegenerative disorders such as progressive supranuclear palsy. Evaluation of the different gaze disorders is a bane of most budding neurologists and neurosurgeons. However, a simple and systematic clinical approach to this problem can make their early diagnosis rather easy.

  1. Gaze Direction Detection in Autism Spectrum Disorder

    Science.gov (United States)

    Forgeot d'Arc, Baudouin; Delorme, Richard; Zalla, Tiziana; Lefebvre, Aline; Amsellem, Frédérique; Moukawane, Sanaa; Letellier, Laurence; Leboyer, Marion; Mouren, Marie-Christine; Ramus, Franck

    2017-01-01

    Detecting where our partners direct their gaze is an important aspect of social interaction. An atypical gaze processing has been reported in autism. However, it remains controversial whether children and adults with autism spectrum disorder interpret indirect gaze direction with typical accuracy. This study investigated whether the detection of…

  2. Eye Gaze in Creative Sign Language

    Science.gov (United States)

    Kaneko, Michiko; Mesch, Johanna

    2013-01-01

    This article discusses the role of eye gaze in creative sign language. Because eye gaze conveys various types of linguistic and poetic information, it is an intrinsic part of sign language linguistics in general and of creative signing in particular. We discuss various functions of eye gaze in poetic signing and propose a classification of gaze…

  3. Eye Gaze in Creative Sign Language

    Science.gov (United States)

    Kaneko, Michiko; Mesch, Johanna

    2013-01-01

    This article discusses the role of eye gaze in creative sign language. Because eye gaze conveys various types of linguistic and poetic information, it is an intrinsic part of sign language linguistics in general and of creative signing in particular. We discuss various functions of eye gaze in poetic signing and propose a classification of gaze…

  4. Trends and Techniques in Visual Gaze Analysis

    CERN Document Server

    Stellmach, Sophie; Dachselt, Raimund; Lindley, Craig A

    2010-01-01

    Visualizing gaze data is an effective way for the quick interpretation of eye tracking results. This paper presents a study investigation benefits and limitations of visual gaze analysis among eye tracking professionals and researchers. The results were used to create a tool for visual gaze analysis within a Master's project.

  5. Creating Gaze Annotations in Head Mounted Displays

    DEFF Research Database (Denmark)

    Mardanbeigi, Diako; Qvarfordt, Pernilla

    2015-01-01

    , the user simply captures an image using the HMD’s camera, looks at an object of interest in the image, and speaks out the information to be associated with the object. The gaze location is recorded and visualized with a marker. The voice is transcribed using speech recognition. Gaze annotations can......To facilitate distributed communication in mobile settings, we developed GazeNote for creating and sharing gaze annotations in head mounted displays (HMDs). With gaze annotations it possible to point out objects of interest within an image and add a verbal description. To create an annota- tion...

  6. Physics of ball sports

    Science.gov (United States)

    Cohen, C.; Clanet, C.

    2016-06-01

    Ball sports have been part of human history for thousands of years [1]. Nowadays, 13 of them are part of the Olympic games (badminton, basketball, beach volley, football/soccer, golf, handball, hockey, rugby, table tennis, tennis, volleyball, water polo, ice hockey). All these games differ by launcher (hand, club, racket, bat), ball (size, shape and mass), pitch size and number of players. These differences induce different ball velocities. Apart from the velocities and the way to maximize them, we discuss in this article the ball trajectories and their impact on the size of sports fields.

  7. The Expressive Gaze Model: Using Gaze to Express Emotion

    Science.gov (United States)

    2010-07-01

    Thomas and O. Johnston, Disney Animation : The Illusion of Life, Abbeville Press, 1981. 2. B. Lance and S.C. Marsella, “Emotionally Expressive Head and...Thomas and Ollie Johnston Early animators realized that the eyes are an important aspect of the human face regarding the communication and expression...of emotion. They also found that properly animating believ- able, emotionally expressive gaze is extremely dif- ficult. If it’s done improperly

  8. Off-the-Shelf Gaze Interaction

    DEFF Research Database (Denmark)

    San Agustin, Javier

    People with severe motor-skill disabilities are often unable to use standard input devices such as a mouse or a keyboard to control a computer and they are, therefore, in strong need for alternative input devices. Gaze tracking offers them the possibility to use the movements of their eyes...... of the challenges introduced by the use of low-cost and off-the-shelf components for gaze interaction. The main contributions are: - Development and performance evaluation of the ITU Gaze Tracker, an off-the-shelf gaze tracker that uses an inexpensive webcam or video camera to track the user’s eye. The software...... is readily available as open source, offering the possibility to try out gaze interaction for a low price and to analyze, improve and extend the software by modifying the source code. - A novel gaze estimation method based on homographic mappings between planes. No knowledge about the hardware configuration...

  9. Happy Balls, Unhappy Balls, and Newton's Cradle

    Science.gov (United States)

    Kagan, David

    2010-01-01

    The intricacies of Newton's Cradle are well covered in the literature going as far back as the time of Newton! These discussions generally center on the highly elastic collisions of metal spheres. Thanks to the invention of happy and unhappy balls, you can build and study the interaction of less elastic systems (see Fig. 1).

  10. Happy Balls, Unhappy Balls, and Newton's Cradle

    Science.gov (United States)

    Kagan, David

    2010-01-01

    The intricacies of Newton's Cradle are well covered in the literature going as far back as the time of Newton! These discussions generally center on the highly elastic collisions of metal spheres. Thanks to the invention of happy and unhappy balls, you can build and study the interaction of less elastic systems (see Fig. 1).

  11. Gameplay experience in a gaze interaction game

    CERN Document Server

    Nacke, Lennart E; Sasse, Dennis; Lindley, Craig A

    2010-01-01

    Assessing gameplay experience for gaze interaction games is a challenging task. For this study, a gaze interaction Half-Life 2 game modification was created that allowed eye tracking control. The mod was deployed during an experiment at Dreamhack 2007, where participants had to play with gaze navigation and afterwards rate their gameplay experience. The results show low tension and negative affects scores on the gameplay experience questionnaire as well as high positive challenge, immersion and flow ratings. The correlation between spatial presence and immersion for gaze interaction was high and yields further investigation. It is concluded that gameplay experience can be correctly assessed with the methodology presented in this paper.

  12. Compact Q-balls

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; da Rocha, R

    2016-01-01

    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  13. Theory of ball lightning

    CERN Document Server

    Wu, H -C

    2014-01-01

    We present a comprehensive explanation on ball lightning, a luminous sphere occasionally witnessed after ordinary lightning. In the last decade, it has been well established that natural lightning routinely generates relativistic electrons, which account for observed x rays. So we assume that, in a ball lightning event, a well-defined relativistic electron bunch is produced by the stepped leader of lightning. When this electron bunch strikes various media, a powerful microwave pulse is emitted by the coherent transition radiation mechanism. This intense microwave ionizes air, evacuates plasmas by its radiation pressure to form a globular plasma cavity, and then gets trapped inside the cavity. This theory successfully explains all characteristics of ball lightning, especially the appearance of ball lightning in fully-screened aircraft. Moreover, the proposed radiation mechanism fully explains the strongest radio signals from lightning and nanosecond spikes in the signals are direct evidences on the generation ...

  14. Gaze behaviors of goaltenders under spatial-temporal constraints.

    Science.gov (United States)

    Panchuk, D; Vickers, J N

    2006-12-01

    It is still not known what underlies successful performance in goaltending. Some studies have reported that advanced cues from the shooter's body (hip, kicking leg or support leg) are most important (Savelsbergh, G. J. P., Williams, A. M., Van der Kamp, J., & Ward, P. (2002). Visual search, anticipation and expertise in soccer goalkeepers. Journal of Sports Sciences, 20, 279-287; Savelsbergh, G. J. P., Williams, A. M., Van der Kamp, J., & Ward, P. (2005). Anticipation and visual search behaviour in expert soccer goalkeepers. Ergonomics, 48, 1686-1697; Williams, A. M., & Burwitz, L. (1993). Advanced cue utilization in soccer. In T. Reilly, J. Clarys, & A. Stibbe (Eds.), Science and football II (pp. 239-243). London, England: E&FN Spon), while others have found that the early tracking of the object prior to and during flight is most critical (Bard, C., & Fleury, M. (1981). Considering eye movement as a predictor of attainment. In: I. M. Cockerill, & W. M. MacGillvary (Eds.), Vision and Sport (pp. 28-41). Cheltenham, England: Stanley Thornes (Publishers) Ltd.). These results are similar to those found in a number of interceptive timing studies (Land, M. F., & McLeod, P. (2000). From eye movements to actions: How batsmen hit the ball. Nature Neuroscience, 3, 1340-1345; Ripoll and Fleurance, 1988; Vickers, J. N., & Adolphe, R. M. (1997). Gaze behaviour during a ball tracking and aiming skill. International Journal of Sports Vision, 4, 18-27). The coupled gaze and motor behavior of elite goaltenders were determined while responding to wrist shots taken from 5 m and 10 m on ice. The results showed that the goalies faced shots that were significantly different in phase durations due to distance (5 versus 10 m), but this was not a factor in making saves. Instead, the ability to stop the puck was dependent on the location, onset and duration of the final fixation/tracking gaze (or quiet eye) prior to initiating the saving action. The relative onset of quiet eye was

  15. Eye gaze as relational evaluation: averted eye gaze leads to feelings of ostracism and relational devaluation.

    Science.gov (United States)

    Wirth, James H; Sacco, Donald F; Hugenberg, Kurt; Williams, Kipling D

    2010-07-01

    Eye gaze is often a signal of interest and, when noticed by others, leads to mutual and directional gaze. However, averting one's eye gaze toward an individual has the potential to convey a strong interpersonal evaluation. The averting of eye gaze is the most frequently used nonverbal cue to indicate the silent treatment, a form of ostracism. The authors argue that eye gaze can signal the relational value felt toward another person. In three studies, participants visualized interacting with an individual displaying averted or direct eye gaze. Compared to receiving direct eye contact, participants receiving averted eye gaze felt ostracized, signaled by thwarted basic need satisfaction, reduced explicit and implicit self-esteem, lowered relational value, and increased temptations to act aggressively toward the interaction partner.

  16. Follow my eyes: the gaze of politicians reflexively captures the gaze of ingroup voters.

    Directory of Open Access Journals (Sweden)

    Marco Tullio Liuzza

    Full Text Available Studies in human and non-human primates indicate that basic socio-cognitive operations are inherently linked to the power of gaze in capturing reflexively the attention of an observer. Although monkey studies indicate that the automatic tendency to follow the gaze of a conspecific is modulated by the leader-follower social status, evidence for such effects in humans is meager. Here, we used a gaze following paradigm where the directional gaze of right- or left-wing Italian political characters could influence the oculomotor behavior of ingroup or outgroup voters. We show that the gaze of Berlusconi, the right-wing leader currently dominating the Italian political landscape, potentiates and inhibits gaze following behavior in ingroup and outgroup voters, respectively. Importantly, the higher the perceived similarity in personality traits between voters and Berlusconi, the stronger the gaze interference effect. Thus, higher-order social variables such as political leadership and affiliation prepotently affect reflexive shifts of attention.

  17. Aerodynamics of sports balls

    Science.gov (United States)

    Mehta, R. D.

    1985-01-01

    Research data on the aerodynamic behavior of baseballs and cricket and golf balls are summarized. Cricket balls and baseballs are roughly the same size and mass but have different stitch patterns. Both are thrown to follow paths that avoid a batter's swing, paths that can curve if aerodynamic forces on the balls' surfaces are asymmetric. Smoke tracer wind tunnel tests and pressure taps have revealed that the unbalanced side forces are induced by tripping the boundary layer on the seam side and producing turbulence. More particularly, the greater pressures are perpendicular to the seam plane and only appear when the balls travel at velocities high enough so that the roughness length matches the seam heigh. The side forces, once tripped, will increase with spin velocity up to a cut-off point. The enhanced lift coefficient is produced by the Magnus effect. The more complex stitching on a baseball permits greater variations in the flight path curve and, in the case of a knuckleball, the unsteady flow effects. For golf balls, the dimples trip the boundary layer and the high spin rate produces a lift coefficient maximum of 0.5, compared to a baseball's maximum of 0.3. Thus, a golf ball travels far enough for gravitational forces to become important.

  18. Adaptive gaze control for object detection

    NARCIS (Netherlands)

    De Croon, G.C.H.E.; Postma, E.O.; Van den Herik, H.J.

    2011-01-01

    We propose a novel gaze-control model for detecting objects in images. The model, named act-detect, uses the information from local image samples in order to shift its gaze towards object locations. The model constitutes two main contributions. The first contribution is that the model’s setup makes

  19. Wrist-worn pervasive gaze interaction

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Lund, Haakon; Biermann, Florian

    2016-01-01

    This paper addresses gaze interaction for smart home control, conducted from a wrist-worn unit. First we asked ten people to enact the gaze movements they would propose for e.g. opening a door or adjusting the room temperature. On basis of their suggestions we built and tested different versions ...

  20. Culture and Listeners' Gaze Responses to Stuttering

    Science.gov (United States)

    Zhang, Jianliang; Kalinowski, Joseph

    2012-01-01

    Background: It is frequently observed that listeners demonstrate gaze aversion to stuttering. This response may have profound social/communicative implications for both fluent and stuttering individuals. However, there is a lack of empirical examination of listeners' eye gaze responses to stuttering, and it is unclear whether cultural background…

  1. Culture and Listeners' Gaze Responses to Stuttering

    Science.gov (United States)

    Zhang, Jianliang; Kalinowski, Joseph

    2012-01-01

    Background: It is frequently observed that listeners demonstrate gaze aversion to stuttering. This response may have profound social/communicative implications for both fluent and stuttering individuals. However, there is a lack of empirical examination of listeners' eye gaze responses to stuttering, and it is unclear whether cultural background…

  2. Gaze-Based Controlling a Vehicle

    DEFF Research Database (Denmark)

    Mardanbeigi, Diako; Witzner Hansen, Dan

    Research and applications of gaze interaction has mainly been conducted on a 2 dimensional surface (usually screens) for controlling a computer or controlling the movements of a robot. Emerging wearable and mobile technologies, such as google glasses may shift how gaze is used as an interactive...

  3. Tunguska Dark Matter Ball

    CERN Document Server

    Froggatt, C D

    2014-01-01

    It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

  4. The bowling balls

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    10 November 1972: CERN’s Bent Stumpe places an order for 12 bowling balls for a total cost of 95 US dollars. Although not evident at first sight, he is buying the heart of some of the first tracking devices to be used in the SPS control room. Today, Bent Stumpe’s device would be called a desktop mouse…   The first order for 4 bowling balls later changed to 12 balls. The bowling balls became the heart of Bent Stumpe's mouse. Almost 40 years ago, the web, Wikipedia and Google did not exist and it was much more difficult to know whether other people in other parts of the world or even in the same laboratory were facing the same problems or developing the same tools. At that time, Bent Stumpe was an electronics engineer, newly recruited to work on developments for the SPS Central Control room. One of the things his supervisor asked him to build as soon as possible was a device to control a pointer on a screen, also called a tracker ball. The heart of the device was the...

  5. Interacting Q-balls

    CERN Document Server

    Brihaye, Yves

    2007-01-01

    We construct explicit examples of new axially symmetric, non-spinning Q-ball solutions that have not been studied so far. These solutions can be interpreted as angular excitations of the fundamental Q-balls and are related to the spherical harmonics. Correspondingly, they have higher energy and their energy densities possess two local maxima on the positive z-axis. We also study two Q-balls interacting via a potential term in 3+1 dimensions and construct examples of stationary, solitonic-like objects in (3+1)-dimensional flat space-time that consist of two interacting global scalar fields. We concentrate on configurations composed of one spinning and one non-spinning Q-ball and study the parameter-dependence of the energy and charges of the configuration. In addition, we present numerical evidence that for fixed values of the coupling constants two different types of 2-Q-ball solutions exist: solutions with defined parity, but also solutions which are asymmetric with respect to reflexion through the x-y-axis.

  6. Gliding and Saccadic Gaze Gesture Recognition in Real Time

    DEFF Research Database (Denmark)

    Rozado, David; San Agustin, Javier; Rodriguez, Francisco

    2012-01-01

    paradigm in the context of human-machine interaction as low-cost gaze trackers become more ubiquitous. The viability of gaze gestures as an innovative way to control a computer rests on how easily they can be assimilated by potential users and also on the ability of machine learning algorithms...... to discriminate intentional gaze gestures from typical gaze activity performed during standard interaction with electronic devices. In this work, through a set of experiments and user studies, we evaluate the performance of two different gaze gestures modalities, gliding gaze gestures and saccadic gaze gestures...

  7. Gazes

    DEFF Research Database (Denmark)

    Khawaja, Iram

    2015-01-01

    of passing. The analysis of the young Muslim men and women’s narratives points towards the particular embodied, intersectional and local possibilities for becoming and being visible as a legitimate Muslim subject in a society fraught with stereotypical and often negative images and discourses on Islam...

  8. Split Q-balls

    Science.gov (United States)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.

    2017-02-01

    We investigate the presence of non-topological solutions of the Q-ball type in (1 , 1) spacetime dimensions. The model engenders the global U (1) symmetry and is of the k-field type, since it contains a new term, of the fourth-order power in the derivative of the complex scalar field. It supports analytical solution of the Q-ball type which is stable quantum mechanically. The new solution engenders an interesting behavior, with the charge and energy densities unveiling a splitting profile.

  9. Wrist-worn pervasive gaze interaction

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Lund, Haakon; Biermann, Florian;

    2016-01-01

    This paper addresses gaze interaction for smart home control, conducted from a wrist-worn unit. First we asked ten people to enact the gaze movements they would propose for e.g. opening a door or adjusting the room temperature. On basis of their suggestions we built and tested different versions...... selection. Their subjective evaluations were positive with regard to the speed of the interaction. We conclude that gaze gesture input seems feasible for fast and brief remote control of smart home technology provided that robustness of tracking is improved....

  10. The Mathematics of Bouncing Balls.

    Science.gov (United States)

    Martin, Kathleen

    1989-01-01

    Describes an activity which uses the computer to produce an environment that encourages an inductive reasoning approach to ratio and proportion through a billiard ball simulation. Provides examples of graphs and bouncing ball data. (RT)

  11. A Spiky Ball

    OpenAIRE

    Naszódi, Márton

    2015-01-01

    The Illumination Problem may be phrased as the problem of covering a convex body in Euclidean $n$-space by a minimum number of translates of its interior. By a probabilistic argument, we show that, arbitrarily close to the Euclidean ball, there is a centrally symmetric convex body of illumination number exponentially large in the dimension.

  12. Have a Ball

    Institute of Scientific and Technical Information of China (English)

    程炜

    2003-01-01

    Before being sent to prison Carl drove big cars and ate in expensive restaurants. No one knew where he got his money but he was certainly having a ball. When the judge sentenced him.to prison he said, “I hope you have a bail, Carl.” To have a bait is to have a wonderful time.

  13. The Use of Gaze to Control Drones

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Alapetite, Alexandre; MacKenzie, I. Scott

    2014-01-01

    This paper presents an experimental investigation of gaze-based control modes for unmanned aerial vehicles (UAVs or “drones”). Ten participants performed a simple flying task. We gathered empirical measures, including task completion time, and examined the user experience for difficulty, reliabil...... was considered significantly more reliable than the others. We discuss design and performance issues for the gaze-plus-manual split of controls when drones are operated using gaze in conjunction with tablets, near-eye displays (glasses), or monitors.......This paper presents an experimental investigation of gaze-based control modes for unmanned aerial vehicles (UAVs or “drones”). Ten participants performed a simple flying task. We gathered empirical measures, including task completion time, and examined the user experience for difficulty...

  14. A Gaze Interactive Textual Smartwatch Interface

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Biermann, Florian; Askø Madsen, Janus

    2015-01-01

    , but not where on the screen they are looking. To counter the motor noise we present a word-by-word textual UI that shows temporary command options to be executed by gaze-strokes. Twenty-seven participants conducted a simulated smartwatch task and were able to reliably perform commands that would adjust...... the speed of word presentation or make regressions. We discuss future design and usage options for a textual smartwatch gaze interface....

  15. Latvijas Gaze buyback likely to flop

    Index Scriptorium Estoniae

    2003-01-01

    Veerandi Läti gaasifirma Latvijas Gaze omanik Itera kavatseb lähiajal lõpule viia üheksa protsendi Läti firma aktsiate müügi ettevõttele Gazprom. Gazprom'i kontrolli all on praegu 25 protsenti, Ruhrgas'il 28,66 ning E.ON Energie AG-l 18,06 protsenti Latvijas Gaze aktsiatest

  16. Latvijas Gaze buyback likely to flop

    Index Scriptorium Estoniae

    2003-01-01

    Veerandi Läti gaasifirma Latvijas Gaze omanik Itera kavatseb lähiajal lõpule viia üheksa protsendi Läti firma aktsiate müügi ettevõttele Gazprom. Gazprom'i kontrolli all on praegu 25 protsenti, Ruhrgas'il 28,66 ning E.ON Energie AG-l 18,06 protsenti Latvijas Gaze aktsiatest

  17. The strategic control of gaze direction in the Tower-of-London task.

    Science.gov (United States)

    Hodgson, T L; Bajwa, A; Owen, A M; Kennard, C

    2000-09-01

    In this paper, we describe a novel approach to the study of problem solving involving the detailed analysis of natural scanning eye movements during the "one-touch" Tower-of-London (TOL) task. We showed subjects a series of pictures depicting two arrangements of colored balls in pockets within the upper and lower halves of a computer display. The task was to plan (but not to execute) the shortest movement sequence required to rearrange the balls in one half of the display (the Workspace) to match the arrangement in the opposite half (the Goalspace) and indicate the minimum number of moves required for problem solution. We report that subjects are more likely to look towards the Goalspace in the initial period after picture presentation, but bias gaze towards the Workspace during the middle of trials. Towards the end of a trial, subjects are once again more likely to fixate the Goalspace. This pattern is found regardless of whether the subjects solve problems by rearranging the balls in the lower or upper visual fields, demonstrating that this strategy correlates with discrete phases in problem solving. A second experiment showed that efficient planners direct their gaze selectively towards the problem critical balls in the Workspace. In contrast, individuals who make errors spend more time looking at irrelevant items and are strongly influenced by the movement strategy needed to solve the preceding problem. We conclude that efficient solution of the TOL requires the capacity to generate and flexibly shift between control sets, including those underlying ocular scanning. The role of working memory and the prefrontal cerebral cortex in the task are discussed.

  18. Postural Control During Cascade Ball Juggling: Effects of Expertise and Base of Support.

    Science.gov (United States)

    Rodrigues, Sérgio T; Polastri, Paula F; Gotardi, Gisele C; Aguiar, Stefane A; Mesaros, Marcelo R; Pestana, Mayara B; Barbieri, Fabio A

    2016-08-01

    Cascade ball juggling is a complex perceptual motor skill which requires efficient postural stabilization. The aim of this study was to investigate effects of experience (expert and intermediate groups) and foot distance (wide and narrow stances) on body sway of jugglers during three ball cascade juggling. A total of 10 expert jugglers and 11 intermediate jugglers participated in this study. Participants stood barefoot on the force plate (some participants wore a gaze tracking system), with feet maintained in wide and narrow conditions and performed three 40-seconds trials of the three-ball juggling task. Dependent variables were sway mean velocity, amplitude, mean frequency, number of ball cycles, fixation number, mean duration and its variability, and area of gaze displacement. Two-way analyses of variance with factors for group and condition were conducted. Experts' body sway was characterized by lower velocity and smaller amplitude as compared to intermediate group. Interestingly, the more challenging (narrow) basis of support caused significant attenuation in body sway only for the intermediate group. These data suggest that expertise in cascade juggling was associated with refined postural control.

  19. The Gaze and Being Gazed:From Madama Butterfly to M. Butterfly

    Institute of Scientific and Technical Information of China (English)

    李琼华

    2012-01-01

      Abstrac]Through the analysis of both Madama Butterfly and M. Butterfly,this paper expores the gaze of the Occidental upon the Oriental especially the women. It analyzes the change of the Occi-dental gaze and gets the result that the misconception of the Oriental and its culture might form a big mockery to the Orientalism.

  20. Gaze perception in social anxiety and social anxiety disorder.

    Science.gov (United States)

    Schulze, Lars; Renneberg, Babette; Lobmaier, Janek S

    2013-12-16

    Clinical observations suggest abnormal gaze perception to be an important indicator of social anxiety disorder (SAD). Experimental research has yet paid relatively little attention to the study of gaze perception in SAD. In this article we first discuss gaze perception in healthy human beings before reviewing self-referential and threat-related biases of gaze perception in clinical and non-clinical socially anxious samples. Relative to controls, socially anxious individuals exhibit an enhanced self-directed perception of gaze directions and demonstrate a pronounced fear of direct eye contact, though findings are less consistent regarding the avoidance of mutual gaze in SAD. Prospects for future research and clinical implications are discussed.

  1. Examining Vision and Attention in Sports Performance Using a Gaze-Contingent Paradigm

    Directory of Open Access Journals (Sweden)

    Donghyun Ryu

    2012-10-01

    Full Text Available In time-constrained activities, such as competitive sports, the rapid acquisition and comprehension of visual information is vital for successful performance. Currently our understanding of how and what visual information is acquired and how this changes with skill development is quite rudimentary. Interpretation of eye movement behaviour is limited by uncertainties surrounding the relationship between attention, line-of-gaze data, and the mechanism of information pick-up from different sectors of the visual field. We used gaze-contingent display methodology to provide a selective information presentation to the central and peripheral parts of the visual field while performing a decision-making task. Eleven skilled and 11 less-skilled players watched videos of basketball scenarios under three different vision conditions (tunnel, masked, and full vision and in a forced-choice paradigm responded whether it was more appropriate for the ball carrier to pass or drive. In the tunnel and mask conditions vision was selectively restricted to, or occluded from, 5o around the line of gaze respectively. The skilled players showed significantly higher response accuracy and faster response times compared to their lesser skilled counterparts irrespective of the vision condition, demonstrating the skilled players' superiority in information extraction irrespective of the segment of visual field they rely on. Findings suggest that the capability to interpret visual information appears to be the key limiting factor to expert performance rather than the sector of the visual field in which the information is detected.

  2. A 2D eye gaze estimation system with low-resolution webcam images

    Directory of Open Access Journals (Sweden)

    Kim Jin

    2011-01-01

    Full Text Available Abstract In this article, a low-cost system for 2D eye gaze estimation with low-resolution webcam images is presented. Two algorithms are proposed for this purpose, one for the eye-ball detection with stable approximate pupil-center and the other one for the eye movements' direction detection. Eyeball is detected using deformable angular integral search by minimum intensity (DAISMI algorithm. Deformable template-based 2D gaze estimation (DTBGE algorithm is employed as a noise filter for deciding the stable movement decisions. While DTBGE employs binary images, DAISMI employs gray-scale images. Right and left eye estimates are evaluated separately. DAISMI finds the stable approximate pupil-center location by calculating the mass-center of eyeball border vertices to be employed for initial deformable template alignment. DTBGE starts running with initial alignment and updates the template alignment with resulting eye movements and eyeball size frame by frame. The horizontal and vertical deviation of eye movements through eyeball size is considered as if it is directly proportional with the deviation of cursor movements in a certain screen size and resolution. The core advantage of the system is that it does not employ the real pupil-center as a reference point for gaze estimation which is more reliable against corneal reflection. Visual angle accuracy is used for the evaluation and benchmarking of the system. Effectiveness of the proposed system is presented and experimental results are shown.

  3. Analysis of Duration Risk of PERT Network Planning Project Based on Crystal Ball%基于Crystal Ball的PERT网络计划项目工期风险分析

    Institute of Scientific and Technical Information of China (English)

    胡静静

    2012-01-01

    文章介绍了网络计划技术,对PERT网络计划项目各活动持续时间的确定进行了分析,总结了使用Crystal Ball进行风险分析的步骤,构建了某PERT网络计划项目各活动的时问参数的Excel模型.在此基础上,使用Crystal Ball建立该项目的工期风险分析模型,并对该模型进行风险分析,获得有效的分析结果.

  4. Frequency analysis of gaze points with CT colonography interpretation using eye gaze tracking system

    Science.gov (United States)

    Tsutsumi, Shoko; Tamashiro, Wataru; Sato, Mitsuru; Okajima, Mika; Ogura, Toshihiro; Doi, Kunio

    2017-03-01

    It is important to investigate eye tracking gaze points of experts, in order to assist trainees in understanding of image interpretation process. We investigated gaze points of CT colonography (CTC) interpretation process, and analyzed the difference in gaze points between experts and trainees. In this study, we attempted to understand how trainees can be improved to a level achieved by experts in viewing of CTC. We used an eye gaze point sensing system, Gazefineder (JVCKENWOOD Corporation, Tokyo, Japan), which can detect pupil point and corneal reflection point by the dark pupil eye tracking. This system can provide gaze points images and excel file data. The subjects are radiological technologists who are experienced, and inexperienced in reading CTC. We performed observer studies in reading virtual pathology images and examined observer's image interpretation process using gaze points data. Furthermore, we examined eye tracking frequency analysis by using the Fast Fourier Transform (FFT). We were able to understand the difference in gaze points between experts and trainees by use of the frequency analysis. The result of the trainee had a large amount of both high-frequency components and low-frequency components. In contrast, both components by the expert were relatively low. Regarding the amount of eye movement in every 0.02 second we found that the expert tended to interpret images slowly and calmly. On the other hand, the trainee was moving eyes quickly and also looking for wide areas. We can assess the difference in the gaze points on CTC between experts and trainees by use of the eye gaze point sensing system and based on the frequency analysis. The potential improvements in CTC interpretation for trainees can be evaluated by using gaze points data.

  5. Models for Gaze Tracking Systems

    Directory of Open Access Journals (Sweden)

    Villanueva Arantxa

    2007-01-01

    Full Text Available One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.

  6. Models for Gaze Tracking Systems

    Directory of Open Access Journals (Sweden)

    Arantxa Villanueva

    2007-10-01

    Full Text Available One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.

  7. Atypical face gaze in autism.

    Science.gov (United States)

    Trepagnier, Cheryl; Sebrechts, Marc M; Peterson, Rebecca

    2002-06-01

    An eye-tracking study of face and object recognition was conducted to clarify the character of face gaze in autistic spectrum disorders. Experimental participants were a group of individuals diagnosed with Asperger's disorder or high-functioning autistic disorder according to their medical records and confirmed by the Autism Diagnostic Interview-Revised (ADI-R). Controls were selected on the basis of age, gender, and educational level to be comparable to the experimental group. In order to maintain attentional focus, stereoscopic images were presented in a virtual reality (VR) headset in which the eye-tracking system was installed. Preliminary analyses show impairment in face recognition, in contrast with equivalent and even superior performance in object recognition among participants with autism-related diagnoses, relative to controls. Experimental participants displayed less fixation on the central face than did control-group participants. The findings, within the limitations of the small number of subjects and technical difficulties encountered in utilizing the helmet-mounted display, suggest an impairment in face processing on the part of the individuals in the experimental group. This is consistent with the hypothesis of disruption in the first months of life, a period that may be critical to typical social and cognitive development, and has important implications for selection of appropriate targets of intervention.

  8. Vestibular and cerebellar contribution to gaze optimality.

    Science.gov (United States)

    Sağlam, Murat; Glasauer, Stefan; Lehnen, Nadine

    2014-04-01

    Patients with chronic bilateral vestibular loss have large gaze variability and experience disturbing oscillopsia, which impacts physical and social functioning, and quality of life. Gaze variability and oscillopsia in these patients are attributed to a deficient vestibulo-ocular reflex, i.e. impaired online feedback motor control. Here, we assessed whether the lack of vestibular input also affects feed-forward motor learning, i.e. the ability to choose optimal movement parameters that minimize variability during active movements such as combined eye-head gaze shifts. A failure to learn from practice and reshape feed-forward motor commands in response to sensory error signals to achieve appropriate movements has been proposed to explain dysmetric gaze shifts in patients with cerebellar ataxia. We, therefore, assessed the differential roles of both sensory vestibular information and the cerebellum in choosing optimal movement kinematics. We have previously shown that, in the course of several gaze shifts, healthy subjects adjust the motor command to minimize endpoint variability also when movements are experimentally altered by an increase in the head moment of inertia. Here, we increased the head inertia in five patients with chronic complete bilateral vestibular loss (aged 45.4±7.1 years, mean±standard deviation), nine patients with cerebellar ataxia (aged 56.7±12.6 years), and 10 healthy control subjects (aged 39.7±6.3 years) while they performed large (75° and 80°) horizontal gaze shifts towards briefly flashed targets in darkness and, using our previous optimal control model, compared their gaze shift parameters to the expected optimal movements with increased head inertia. Patients with chronic bilateral vestibular loss failed to update any of the gaze shift parameters to the new optimum with increased head inertia. Consequently, they displayed highly variable, suboptimal gaze shifts. Patients with cerebellar ataxia updated some movement parameters to

  9. Visual Foraging With Fingers and Eye Gaze.

    Science.gov (United States)

    Jóhannesson, Ómar I; Thornton, Ian M; Smith, Irene J; Chetverikov, Andrey; Kristjánsson, Árni

    2016-03-01

    A popular model of the function of selective visual attention involves search where a single target is to be found among distractors. For many scenarios, a more realistic model involves search for multiple targets of various types, since natural tasks typically do not involve a single target. Here we present results from a novel multiple-target foraging paradigm. We compare finger foraging where observers cancel a set of predesignated targets by tapping them, to gaze foraging where observers cancel items by fixating them for 100 ms. During finger foraging, for most observers, there was a large difference between foraging based on a single feature, where observers switch easily between target types, and foraging based on a conjunction of features where observers tended to stick to one target type. The pattern was notably different during gaze foraging where these condition differences were smaller. Two conclusions follow: (a) The fact that a sizeable number of observers (in particular during gaze foraging) had little trouble switching between different target types raises challenges for many prominent theoretical accounts of visual attention and working memory. (b) While caveats must be noted for the comparison of gaze and finger foraging, the results suggest that selection mechanisms for gaze and pointing have different operational constraints.

  10. Genetics Home Reference: horizontal gaze palsy with progressive scoliosis

    Science.gov (United States)

    ... Health Conditions HGPPS horizontal gaze palsy with progressive scoliosis Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description Horizontal gaze palsy with progressive scoliosis ( HGPPS ) is a disorder that affects vision and ...

  11. suPAR: the molecular crystal ball

    DEFF Research Database (Denmark)

    Thunø, Maria; Macho, Betina; Eugen-Olsen, Jesper

    2009-01-01

    soluble urokinase Plasminogen Activator Receptor (suPAR) levels reflect inflammation and elevated suPAR levels are found in several infectious diseases and cancer. suPAR exists in three forms; suPAR(I-III), suPAR(II-III) and suPAR(I) which show different properties due to structural differences....... Studies suggest that full-length suPAR is a regulator of uPAR/uPA by actingas uPA-scavenger, whereas the cleaved suPAR(II-III) act as a chemotactic agent promoting the immune response via the SRSRY sequence in the linker-region. This review focus on the various suPAR fragments and their involvement...

  12. Educational Technology in the Crystal Ball.

    Science.gov (United States)

    Langham-Johnson, Shirley

    This paper predicts that microelectronic circuitry will have an impact on education comparable to that of the industrial revolution or the invention of the printing press. Present conditions influencing educational technology and trends are considered in light of five considerations: (1) recent redefinitions of what educational technology is; (2)…

  13. suPAR: The Molecular Crystal Ball

    Directory of Open Access Journals (Sweden)

    Maria Thunø

    2009-01-01

    Full Text Available soluble urokinase Plasminogen Activator Receptor (suPAR levels reflect inflammation and elevated suPAR levels are found in several infectious diseases and cancer. suPAR exists in three forms; suPARI-III, suPARII-III and suPARI which show different properties due to structural differences. Studies suggest that full-length suPAR is a regulator of uPAR/uPA by acting as uPA-scavenger, whereas the cleaved suPARII-III act as a chemotactic agent promoting the immune response via the SRSRY sequence in the linker-region. This review focus on the various suPAR fragments and their involvement in inflammation and pathogenic processes. We focus on the molecular mechanisms of the suPAR fragments and the link to the inflammatory process, as this could lead to medical applications in infectious and pathological conditions.

  14. A crystal ball made of agents

    Directory of Open Access Journals (Sweden)

    José Miguel Castillo

    2010-12-01

    Full Text Available This article presents an agent-based solution to model the opinions of an experts group with the aim of predicting possible future scenarios.The need to envision the future is not new; it has existed since the beginning of human-kind. What it is new is the applicable technology that is available in a specific period of time.It is not usual to find a critical social system which evolves according to predictable guidelines or tendencies. Because of that reason, technical prediction based on past and present data is not reliable.This paper includes the process description of eliciting information from a group of experts and a real case study.

  15. Fractal fluctuations in gaze speed visual search.

    Science.gov (United States)

    Stephen, Damian G; Anastas, Jason

    2011-04-01

    Visual search involves a subtle coordination of visual memory and lower-order perceptual mechanisms. Specifically, the fluctuations in gaze may provide support for visual search above and beyond what may be attributed to memory. Prior research indicates that gaze during search exhibits fractal fluctuations, which allow for a wide sampling of the field of view. Fractal fluctuations constitute a case of fast diffusion that may provide an advantage in exploration. We present reanalyses of eye-tracking data collected by Stephen and Mirman (Cognition, 115, 154-165, 2010) for single-feature and conjunction search tasks. Fluctuations in gaze during these search tasks were indeed fractal. Furthermore, the degree of fractality predicted decreases in reaction time on a trial-by-trial basis. We propose that fractality may play a key role in explaining the efficacy of perceptual exploration.

  16. The Gaze as constituent and annihilator

    Directory of Open Access Journals (Sweden)

    Mats Carlsson

    2012-11-01

    Full Text Available This article aims to join the contemporary effort to promote a psychoanalytic renaissance within cinema studies, post Post-Theory. In trying to shake off the burden of the 1970s film theory's distortion of the Lacanian Gaze, rejuvenating it with the strength of the Real and fusing it with Freudian thoughts on the uncanny, hopefully this new dawn can be reached. I aspire to conceptualize the Gaze in a straightforward manner. This in order to obtain an instrument for the identification of certain strategies within the filmic realm aimed at depicting the subjective destabilizing of diegetic characters as well as thwarting techniques directed at the spectorial subject. In setting this capricious Gaze against the uncanny phenomena described by Freud, we find that these two ideas easily intertwine into a draft description of a powerful, potentially reconstitutive force worth being highlighted.

  17. Emotional expression modulates perceived gaze direction.

    Science.gov (United States)

    Lobmaier, Janek S; Tiddeman, Bernard P; Perrett, David I

    2008-08-01

    Gaze perception is an important social skill, as it portrays information about what another person is attending to. Gaze direction has been shown to affect interpretation of emotional expression. Here the authors investigate whether the emotional facial expression has a reciprocal influence on interpretation of gaze direction. In a forced-choice yes-no task, participants were asked to judge whether three faces expressing different emotions (anger, fear, happiness, and neutral) in different viewing angles were looking at them or not. Happy faces were more likely to be judged as looking at the observer than were angry, fearful, or neutral faces. Angry faces were more often judged as looking at the observer than were fearful and neutral expressions. These findings are discussed on the background of approach and avoidance orientation of emotions and of the self-referential positivity bias.

  18. BLEACHING NEPTUNE BALLS

    Directory of Open Access Journals (Sweden)

    BONET Maria Angeles

    2014-05-01

    Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

  19. A Direct Link between Gaze Perception and Social Attention

    Science.gov (United States)

    Bayliss, Andrew P.; Bartlett, Jessica; Naughtin, Claire K.; Kritikos, Ada

    2011-01-01

    How information is exchanged between the cognitive mechanisms responsible for gaze perception and social attention is unclear. These systems could be independent; the "gaze cueing" effect could emerge from the activation of a general-purpose attentional mechanism that is ignorant of the social nature of the gaze cue. Alternatively, orienting to…

  20. Gaze Following Is Modulated by Expectations Regarding Others' Action Goals.

    Directory of Open Access Journals (Sweden)

    Jairo Perez-Osorio

    Full Text Available Humans attend to social cues in order to understand and predict others' behavior. Facial expressions and gaze direction provide valuable information to infer others' mental states and intentions. The present study examined the mechanism of gaze following in the context of participants' expectations about successive action steps of an observed actor. We embedded a gaze-cueing manipulation within an action scenario consisting of a sequence of naturalistic photographs. Gaze-induced orienting of attention (gaze following was analyzed with respect to whether the gaze behavior of the observed actor was in line or not with the action-related expectations of participants (i.e., whether the actor gazed at an object that was congruent or incongruent with an overarching action goal. In Experiment 1, participants followed the gaze of the observed agent, though the gaze-cueing effect was larger when the actor looked at an action-congruent object relative to an incongruent object. Experiment 2 examined whether the pattern of effects observed in Experiment 1 was due to covert, rather than overt, attentional orienting, by requiring participants to maintain eye fixation throughout the sequence of critical photographs (corroborated by monitoring eye movements. The essential pattern of results of Experiment 1 was replicated, with the gaze-cueing effect being completely eliminated when the observed agent gazed at an action-incongruent object. Thus, our findings show that covert gaze following can be modulated by expectations that humans hold regarding successive steps of the action performed by an observed agent.

  1. Children with ASD Can Use Gaze to Map New Words

    Science.gov (United States)

    Bean Ellawadi, Allison; McGregor, Karla K.

    2016-01-01

    Background: The conclusion that children with autism spectrum disorders (ASD) do not use eye gaze in the service of word learning is based on one-trial studies. Aims: To determine whether children with ASD come to use gaze in the service of word learning when given multiple trials with highly reliable eye-gaze cues. Methods & Procedures:…

  2. Eye gaze in intelligent user interfaces gaze-based analyses, models and applications

    CERN Document Server

    Nakano, Yukiko I; Bader, Thomas

    2013-01-01

    Remarkable progress in eye-tracking technologies opened the way to design novel attention-based intelligent user interfaces, and highlighted the importance of better understanding of eye-gaze in human-computer interaction and human-human communication. For instance, a user's focus of attention is useful in interpreting the user's intentions, their understanding of the conversation, and their attitude towards the conversation. In human face-to-face communication, eye gaze plays an important role in floor management, grounding, and engagement in conversation.Eye Gaze in Intelligent User Interfac

  3. Ball milling and annealing of Co-50 at% W Powders

    CSIR Research Space (South Africa)

    Bolokang, AS

    2013-04-01

    Full Text Available annealing of unmilled compacts yielded metastable phases. Upon 10 and 20 h ball milling of Co-W powder, no alloying was obtained. Although milling did not yield significant crystal changes in W and Co ground state struc- tures, its effect is evident during...

  4. Towards Wearable Gaze Supported Augmented Cognition

    DEFF Research Database (Denmark)

    Toshiaki Kurauchi, Andrew; Hitoshi Morimoto, Carlos; Mardanbeigi, Diako;

    to reduce the amount of information and provide an appropriate mechanism for low and divided attention interaction. We claim that most current gaze interaction paradigms are not appropriate for wearable computing because they are not designed for divided attention. We have used principles suggested...... by the wearable computing community to develop a gaze supported augmented cognition application with three interaction modes. The application provides information of the person being looked at. The continuous mode updates information every time the user looks at a different face. The key activated discrete mode...

  5. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  6. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  7. Owners' direct gazes increase dogs' attention-getting behaviors.

    Science.gov (United States)

    Ohkita, Midori; Nagasawa, Miho; Kazutaka, Mogi; Kikusui, Takefumi

    2016-04-01

    This study examined whether dogs gain information about human's attention via their gazes and whether they change their attention-getting behaviors (i.e., whining and whimpering, looking at their owners' faces, pawing, and approaching their owners) in response to their owners' direct gazes. The results showed that when the owners gazed at their dogs, the durations of whining and whimpering and looking at the owners' faces were longer than when the owners averted their gazes. In contrast, there were no differences in duration of pawing and likelihood of approaching the owners between the direct and averted gaze conditions. Therefore, owners' direct gazes increased the behaviors that acted as distant signals and did not necessarily involve touching the owners. We suggest that dogs are sensitive to human gazes, and this sensitivity may act as attachment signals to humans, and may contribute to close relationships between humans and dogs.

  8. Gaze interaction with textual user interface

    DEFF Research Database (Denmark)

    Paulin Hansen, John; Lund, Haakon; Madsen, Janus Askø

    2015-01-01

    ” option for text navigation. People readily understood how to execute RSVP command prompts and a majority of them preferred gaze input to a pen pointer. We present the concept of a smartwatch that can track eye movements and mediate command options whenever in proximity of intelligent devices...

  9. Gaze Patterns and Audiovisual Speech Enhancement

    Science.gov (United States)

    Yi, Astrid; Wong, Willy; Eizenman, Moshe

    2013-01-01

    Purpose: In this study, the authors sought to quantify the relationships between speech intelligibility (perception) and gaze patterns under different auditory-visual conditions. Method: Eleven subjects listened to low-context sentences spoken by a single talker while viewing the face of one or more talkers on a computer display. Subjects either…

  10. The Use of Gaze to Control Drones

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Alapetite, Alexandre; MacKenzie, I. Scott

    2014-01-01

    This paper presents an experimental investigation of gaze-based control modes for unmanned aerial vehicles (UAVs or “drones”). Ten participants performed a simple flying task. We gathered empirical measures, including task completion time, and examined the user experience for difficulty, reliabil...

  11. Between Gazes: Feminist, Queer, and 'Other' Films

    DEFF Research Database (Denmark)

    Elias, Camelia

    In this book Camelia Elias introduces key terms in feminist, queer, and postcolonial/diaspora film. Taking her point of departure in the question, "what do you want from me?" she detours through Lacanian theory of the gaze and reframes questions of subjectivity and representation in an entertaini...

  12. Between Gazes: Feminist, Queer, and 'Other' Films

    DEFF Research Database (Denmark)

    Elias, Camelia

    In this book Camelia Elias introduces key terms in feminist, queer, and postcolonial/diaspora film. Taking her point of departure in the question, "what do you want from me?" she detours through Lacanian theory of the gaze and reframes questions of subjectivity and representation in an entertaini...

  13. Images in Christmas Balls

    CERN Document Server

    Van Beveren, E; Rupp, G; Beveren, Eef van; Kleefeld, Frieder; Rupp, George

    2006-01-01

    We describe light-reflection properties of spherically curved mirrors, like balls in the Christmas tree. In particular, we study the position of the image which is formed somewhere beyond the surface of a spherical mirror, when an eye observes the image of a pointlike light source. The considered problem, originally posed by Abu Ali Hasan Ibn al-Haitham -- alias Alhazen -- more than a millennium ago, turned out to have the now well known analytic solution of a biquadratic equation, being still of great relevance, e.g. for the aberration-free construction of telescopes. We do not attempt to perform an exhaustive survey of the rich historical and engineering literature on the subject, but develop a simple pedagogical approach to the issue, which we believe to be of continuing interest in view of its maltreating in many high-school textbooks.

  14. Gaze interaction in UAS video exploitation

    Science.gov (United States)

    Hild, Jutta; Brüstle, Stefan; Heinze, Norbert; Peinsipp-Byma, Elisabeth

    2013-05-01

    A frequently occurring interaction task in UAS video exploitation is the marking or selection of objects of interest in the video. If an object of interest is visually detected by the image analyst, its selection/marking for further exploitation, documentation and communication with the team is a necessary task. Today object selection is usually performed by mouse interaction. As due to sensor motion all objects in the video move, object selection can be rather challenging, especially if strong and fast and ego-motions are present, e.g., with small airborne sensor platforms. In addition to that, objects of interest are sometimes too shortly visible to be selected by the analyst using mouse interaction. To address this issue we propose an eye tracker as input device for object selection. As the eye tracker continuously provides the gaze position of the analyst on the monitor, it is intuitive to use the gaze position for pointing at an object. The selection is then actuated by pressing a button. We integrated this gaze-based "gaze + key press" object selection into Fraunhofer IOSB's exploitation station ABUL using a Tobii X60 eye tracker and a standard keyboard for the button press. Representing the object selections in a spatial relational database, ABUL enables the image analyst to efficiently query the video data in a post processing step for selected objects of interest with respect to their geographical and other properties. An experimental evaluation is presented, comparing gaze-based interaction with mouse interaction in the context of object selection in UAS videos.

  15. Exploring combinations of different color and facial expression stimuli for gaze-independent BCIs

    Directory of Open Access Journals (Sweden)

    Long eChen

    2016-01-01

    Full Text Available AbstractBackground: Some studies have proven that a conventional visual brain computer interface (BCI based on overt attention cannot be used effectively when eye movement control is not possible. To solve this problem, a novel visual-based BCI system based on covert attention and feature attention had been proposed and was called the gaze-independent BCI. Color and shape difference between stimuli and backgrounds have generally been used in examples of gaze-independent BCIs. Recently, a new paradigm based on facial expression change had been presented, and obtained high performance. However, some facial expressions were so similar that users couldn’t tell them apart. Especially they were presented at the same position in a rapid serial visual presentation (RSVP paradigm. Consequently, the performance of BCIs is reduced.New Method: In this paper, we combined facial expressions and colors to optimize the stimuli presentation in the gaze-independent BCI. This optimized paradigm was called the colored dummy face pattern. It is suggested that different colors and facial expressions could help subjects to locate the target and evoke larger event-related potentials (ERPs. In order to evaluate the performance of this new paradigm, two other paradigms were presented, called the grey dummy face pattern and the colored ball pattern. Comparison with Existing Method(s: The key point that determined the value of the colored dummy faces stimuli in BCI systems were whether dummy face stimuli could obtain higher performance than grey faces or colored balls stimuli. Ten healthy subjects (7 male, aged 21-26 years, mean 24.5±1.25 participated in our experiment. Online and offline results of four different paradigms were obtained and comparatively analyzed.Results: The results showed that the colored dummy face pattern could evoke higher P300 and N400 ERP amplitudes, compared with the grey dummy face pattern and the colored ball pattern. Online results showed

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

    Science.gov (United States)

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

    2016-07-01

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

  17. The dynamics of hurricane balls

    Science.gov (United States)

    Andersen, W. L.; Werner, Steven

    2015-09-01

    We examine the theory of the hurricane balls toy. This toy consists of two steel balls, welded together that are sent spinning on a horizontal surface somewhat like a top. Unlike a top, at high frequency the symmetry axis approaches a limiting inclination that is not perpendicular to the surface. We calculate (and experimentally verify) the limiting inclinations for three toy geometries. We find that at high frequencies, hurricane balls provide an easily realized and testable example of the Poinsot theory of freely rotating symmetrical bodies.

  18. Look Together: Analyzing Gaze Coordination with Epistemic Network Analysis

    Directory of Open Access Journals (Sweden)

    Sean eAndrist

    2015-07-01

    Full Text Available When conversing and collaborating in everyday situations, people naturally and interactively align their behaviors with each other across various communication channels, including speech, gesture, posture, and gaze. Having access to a partner's referential gaze behavior has been shown to be particularly important in achieving collaborative outcomes, but the process in which people's gaze behaviors unfold over the course of an interaction and become tightly coordinated is not well understood. In this paper, we present work to develop a deeper and more nuanced understanding of coordinated referential gaze in collaborating dyads. We recruited 13 dyads to participate in a collaborative sandwich-making task and used dual mobile eye tracking to synchronously record each participant's gaze behavior. We used a relatively new analysis technique—epistemic network analysis—to jointly model the gaze behaviors of both conversational participants. In this analysis, network nodes represent gaze targets for each participant, and edge strengths convey the likelihood of simultaneous gaze to the connected target nodes during a given time-slice. We divided collaborative task sequences into discrete phases to examine how the networks of shared gaze evolved over longer time windows. We conducted three separate analyses of the data to reveal (1 properties and patterns of how gaze coordination unfolds throughout an interaction sequence, (2 optimal time lags of gaze alignment within a dyad at different phases of the interaction, and (3 differences in gaze coordination patterns for interaction sequences that lead to breakdowns and repairs. In addition to contributing to the growing body of knowledge on the coordination of gaze behaviors in joint activities, this work has implications for the design of future technologies that engage in situated interactions with human users.

  19. Gazing into the $MgF_2$ ball UV astronomy for the 3rd millenium

    CERN Document Server

    Brosch, N

    1997-01-01

    I examine possible futures for UV astronomy, in view of the past history and collected knowledge of the UV sky through various missions since the early days of Space Astronomy. The last all-sky survey has been by TD-1 in the early 1970s, resulting in reasonable mapping of discrete sources brighter than ~9th mag (monochromatic, UV). Since TD-1, few advances were made in general knowledge of the UV through survey missions, but dedicated, single-object studies advanced mainly through the IUE spectroscopic results. Selected sky areas were surveyed to deeper magnitudes than by TD-1 with various balloon and rocket flights, Shuttle and MIR payloads, etc. The HST offered some UV capability with WFPC 1 and 2, FOC, and presently with STIS, but with small fields of view. The future of UV astronomy seems bleak, with only FUSE with any certainity of being flown and with the recent recommendation of the Dressler committee to emphasize NIR and interferometry into the next millenium. The community's hopes reside therefore wi...

  20. Split-ball resonator

    CERN Document Server

    Kuznetsov, Arseniy I; Fu, Yuan Hsing; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Kivshar, Yuri; Pickard, Daniel S; Lukiyanchuk, Boris

    2014-01-01

    We introduce a new concept of split-ball resonator and demonstrate a strong omnidirectional magnetic dipole response for both gold and silver spherical plasmonic nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole resonance throughout the visible spectral range is demonstrated by a change of the depth and width of the nanoscale cut. We realize this novel concept experimentally by employing the laser-induced transfer method to produce near-perfect spheres and helium ion beam milling to make cuts with the nanometer resolution. Due to high quality of the spherical particle shape, governed by strong surface tension forces during the laser transfer process, and the clean, straight side walls of the cut made by helium ion milling, magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. Structuring arbitrary features on the surface of ideal spherical resonators with nanoscale dimensions provides new ways of engineering hybrid resonant modes and ultra-high near-f...

  1. Joint perception: Gaze and social context

    Directory of Open Access Journals (Sweden)

    Daniel C. Richardson

    2012-07-01

    Full Text Available We found that the way people looked at images was influenced by their belief that others were looking too. If participants believed that an unseen other person was also looking at what they could see, it shifted the balance of their gaze between negative and positive images. The direction of this shift depended upon whether participants thought that later they would be compared against the other person or would be collaborating with them. Changes in the social context influenced both gaze and memory processes, and were not due just to participants’ belief that they are looking at the same images, but also to the belief that they are doing the same task. We believe that this new phenomenon of joint perception reveals the pervasive and subtle effect of social context upon cognitive and perceptual processes.

  2. Noise Challenges in Monomodal Gaze Interaction

    DEFF Research Database (Denmark)

    Skovsgaard, Henrik

    Modern graphical user interfaces (GUIs) are designed with able-bodied users in mind. Operating these interfaces can be impossible for some users who are unable to control the conventional mouse and keyboard. An eye tracking system offers possibilities for independent use and improved quality...... of life via dedicated interface tools especially tailored to the users’ needs (e.g., interaction, communication, e-mailing, web browsing and entertainment). Much effort has been put towards robustness, accuracy and precision of modern eye-tracking systems and there are many available on the market. Even...... stream are most wanted. The work in this thesis presents three contributions that may advance the use of low-cost monomodal gaze tracking and research in the field: - An assessment of a low-cost open-source gaze tracker and two eye tracking systems through an accuracy and precision test and a performance...

  3. Towards gaze-controlled platform games

    DEFF Research Database (Denmark)

    Muñoz, Jorge; Yannakakis, Georgios N.; Mulvey, Fiona

    2011-01-01

    This paper introduces the concept of using gaze as a sole modality for fully controlling player characters of fast-paced action computer games. A user experiment is devised to collect gaze and gameplay data from subjects playing a version of the popular Super Mario Bros platform game. The initial...... analysis shows that there is a rather limited grid around Mario where the efficient player focuses her attention the most while playing the game. The useful grid as we name it, projects the amount of meaningful visual information a designer should use towards creating successful player character...... controllers with the use of artificial intelligence for a platform game like Super Mario. Information about the eyes' position on the screen and the state of the game are utilized as inputs of an artificial neural network, which is trained to approximate which keyboard action is to be performed at each game...

  4. Suppressing Heavy Metal Leaching through Ball Milling of Fly Ash

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-07-01

    Full Text Available Ball milling is investigated as a method of reducing the leaching concentration (often termed stablilization of heavy metals in municipal solid waste incineration (MSWI fly ash. Three heavy metals (Cu, Cr, Pb loose much of their solubility in leachate by treating fly ash in a planetary ball mill, in which collisions between balls and fly ash drive various physical processes, as well as chemical reactions. The efficiency of stabilization is evaluated by analysing heavy metals in the leachable fraction from treated fly ash. Ball milling reduces the leaching concentration of Cu, Cr, and Pb, and water washing effectively promotes stabilization efficiency by removing soluble salts. Size distribution and morphology of particles were analysed by laser particle diameter analysis and scanning electron microscopy. X-ray diffraction analysis reveals significant reduction of the crystallinity of fly ash by milling. Fly ash particles can be activated through this ball milling, leading to a significant decrease in particle size, a rise in its BET-surface, and turning basic crystals therein into amorphous structures. The dissolution rate of acid buffering materials present in activated particles is enhanced, resulting in a rising pH value of the leachate, reducing the leaching out of some heavy metals.

  5. Predictive gaze cues and personality judgments: Should eye trust you?

    Science.gov (United States)

    Bayliss, Andrew P; Tipper, Steven P

    2006-06-01

    Although following another person's gaze is essential in fluent social interactions, the reflexive nature of this gaze-cuing effect means that gaze can be used to deceive. In a gaze-cuing procedure, participants were presented with several faces that looked to the left or right. Some faces always looked to the target (predictive-valid), some never looked to the target (predictive-invalid), and others looked toward and away from the target in equal proportions (nonpredictive). The standard gaze-cuing effects appeared to be unaffected by these contingencies. Nevertheless, participants tended to choose the predictive-valid faces as appearing more trustworthy than the predictive-invalid faces. This effect was negatively related to scores on a scale assessing autistic-like traits. Further, we present tentative evidence that the "deceptive" faces were encoded more strongly in memory than the "cooperative" faces. These data demonstrate the important interactions among attention, gaze perception, facial identity recognition, and personality judgments.

  6. Gaze perception in social anxiety and social anxiety disorder

    Directory of Open Access Journals (Sweden)

    Lars eSchulze

    2013-12-01

    Full Text Available Clinical observations suggest abnormal gaze perception to be an important indicator of social anxiety disorder (SAD. Experimental research has yet paid relatively little attention to the study of gaze perception in SAD. In this article we first discuss gaze perception in healthy human beings before reviewing self-referential and threat-related biases of gaze perception in clinical and non-clinical socially anxious samples. Relative to controls, socially anxious individuals exhibit an enhanced self-directed perception of gaze directions and demonstrate a pronounced fear of direct eye contact, though findings are less consistent regarding the avoidance of mutual gaze in SAD. Prospects for future research and clinical implications are discussed.

  7. Paul Gauguin and the complexity of the primitivist gaze

    Directory of Open Access Journals (Sweden)

    Ruud Welten

    2015-06-01

    Full Text Available The article describes the complexity of Paul Gauguin’s primitivism in a philosophical, more precisely, phenomenological way. It focuses on the phenomenological gaze that, in all its complexity, is active in Gauguin. In his ‘Tahitian’ paintings, we encounter a double gaze: the individual gaze, as painted by Gauguin, makes the spectator aware of the distance between Western and Polynesian cultures. Firstly, colonialism is a gaze that reduces the other to a primitive state in order to esteem this state as more pure and authentic. Secondly, it is precisely the other that resists representation and, as such, gazes back. Gauguin’s anti-conquest, therefore, is not a mere personal, political or cultural revolt, but something that is phenomenological, hidden within the power of his art. Instead, it is the spectator who becomes the intruder, the voyeur, caught red-handed in his own primitivist gaze.

  8. LHC gets the ball rolling

    CERN Multimedia

    2007-01-01

    A technique involving a small ball with a transmitter embedded inside it has been successfully tested in Sector 7-8. The ball is sent through the LHC beam pipes to check the LHC interconnections. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI). During the tests the ball is inserted very carefully into the vacuum chamber.A game of ping-pong at the LHC? On 13 September a rather unusual test was carried out in Sector 7-8 of the accelerator. A ball just a bit smaller than a ping-pong ball was carefully introduced into one of the accelerator’s two vacuum pipes, where it travelled 800 metres in the space of a few mi...

  9. 3D Gaze Estimation from Remote RGB-D Sensors

    OpenAIRE

    Funes Mora, Kenneth Alberto

    2015-01-01

    The development of systems able to retrieve and characterise the state of humans is important for many applications and fields of study. In particular, as a display of attention and interest, gaze is a fundamental cue in understanding people activities, behaviors, intentions, state of mind and personality. Moreover, gaze plays a major role in the communication process, like for showing attention to the speaker, indicating who is addressed or averting gaze to keep the floor. Therefore, many...

  10. Gaze-following behind barriers in domestic dogs.

    Science.gov (United States)

    Met, Amandine; Miklósi, Ádám; Lakatos, Gabriella

    2014-11-01

    Although gaze-following abilities have been demonstrated in a wide range of species, so far no clear evidence has been available for dogs. In the current study, we examined whether dogs follow human gaze behind an opaque barrier in two different contexts, in a foraging situation and in a non-foraging situation (food involved vs. food not involved in the situation). We assumed that dogs will spontaneously follow the human gaze and that the foraging context will have a positive effect on dogs' gaze-following behaviour by causing an expectation in the dogs that food might be hidden somewhere in the room and might be communicated by the experimenter. This expectation presumably positively affects their motivational and attentional state. Here, we report that dogs show evidence of spontaneous gaze-following behind barriers in both situations. According to our findings, the dogs gazed earlier at the barrier in the indicated direction in both contexts. However, as we expected, the context also has some effect on dogs' gaze-following behaviour, as more dogs gazed behind the barrier in the indicated direction in the foraging situation. The present results also support the idea that gaze-following is a characteristic skill in mammals which may more easily emerge in certain functional contexts.

  11. Following gaze: gaze-following behavior as a window into social cognition

    Directory of Open Access Journals (Sweden)

    Stephen V Shepherd

    2010-03-01

    Full Text Available In general, individuals look where they attend and next intend to act. Many animals, including our own species, use observed gaze as a deictic (pointing cue to guide behavior. Among humans, these responses are reflexive and pervasive: they arise within a fraction of a second, act independently of task relevance, and appear to undergird our initial development of language and theory of mind. Human and nonhuman animals appear to share basic gaze-following behaviors, suggesting the foundations of human social cognition may also be present in nonhuman brains.

  12. How Beauty Determines Gaze! Facial Attractiveness and Gaze Duration in Images of Real World Scenes

    Directory of Open Access Journals (Sweden)

    Helmut Leder

    2016-08-01

    Full Text Available We showed that the looking time spent on faces is a valid covariate of beauty by testing the relation between facial attractiveness and gaze behavior. We presented natural scenes which always pictured two people, encompassing a wide range of facial attractiveness. Employing measurements of eye movements in a free viewing paradigm, we found a linear relation between facial attractiveness and gaze behavior: The more attractive the face, the longer and the more often it was looked at. In line with evolutionary approaches, the positive relation was particularly pronounced when participants viewed other sex faces.

  13. How Beauty Determines Gaze! Facial Attractiveness and Gaze Duration in Images of Real World Scenes

    Science.gov (United States)

    Mitrovic, Aleksandra; Goller, Jürgen

    2016-01-01

    We showed that the looking time spent on faces is a valid covariate of beauty by testing the relation between facial attractiveness and gaze behavior. We presented natural scenes which always pictured two people, encompassing a wide range of facial attractiveness. Employing measurements of eye movements in a free viewing paradigm, we found a linear relation between facial attractiveness and gaze behavior: The more attractive the face, the longer and the more often it was looked at. In line with evolutionary approaches, the positive relation was particularly pronounced when participants viewed other sex faces. PMID:27698984

  14. Referential Gaze and Word Learning in Adults with Autism

    Science.gov (United States)

    Aldaqre, Iyad; Paulus, Markus; Sodian, Beate

    2015-01-01

    While typically developing children can use referential gaze to guide their word learning, those with autism spectrum disorder are often described to have problems with that. However, some researchers assume that the ability to follow gaze to select the correct referent can develop in autism later compared to typically developing individuals. To…

  15. Segmentation of object-based video of gaze communication

    DEFF Research Database (Denmark)

    Aghito, Shankar Manuel; Stegmann, Mikkel Bille; Forchhammer, Søren;

    2005-01-01

    Aspects of video communication based on gaze interaction are considered. The overall idea is to use gaze interaction to control video, e.g. for video conferencing. Towards this goal, animation of a facial mask is demonstrated. The animation is based on images using Active Appearance Models (AAM)....

  16. Visual Gaze Estimation by Joint Head and Eye Information

    NARCIS (Netherlands)

    Valenti, R.; Lablack, A.; Sebe, N.; Djeraba, C.; Gevers, T.

    2010-01-01

    In this paper, we present an unconstrained visual gaze estimation system. The proposed method extracts the visual field of view of a person looking at a target scene in order to estimate the approximate location of interest (visual gaze). The novelty of the system is the joint use of head pose and e

  17. Just one look: Direct gaze briefly disrupts visual working memory.

    Science.gov (United States)

    Wang, J Jessica; Apperly, Ian A

    2017-04-01

    Direct gaze is a salient social cue that affords rapid detection. A body of research suggests that direct gaze enhances performance on memory tasks (e.g., Hood, Macrae, Cole-Davies, & Dias, Developmental Science, 1, 67-71, 2003). Nonetheless, other studies highlight the disruptive effect direct gaze has on concurrent cognitive processes (e.g., Conty, Gimmig, Belletier, George, & Huguet, Cognition, 115(1), 133-139, 2010). This discrepancy raises questions about the effects direct gaze may have on concurrent memory tasks. We addressed this topic by employing a change detection paradigm, where participants retained information about the color of small sets of agents. Experiment 1 revealed that, despite the irrelevance of the agents' eye gaze to the memory task at hand, participants were worse at detecting changes when the agents looked directly at them compared to when the agents looked away. Experiment 2 showed that the disruptive effect was relatively short-lived. Prolonged presentation of direct gaze led to recovery from the initial disruption, rather than a sustained disruption on change detection performance. The present study provides the first evidence that direct gaze impairs visual working memory with a rapidly-developing yet short-lived effect even when there is no need to attend to agents' gaze.

  18. The Development of Emotional Face and Eye Gaze Processing

    Science.gov (United States)

    Hoehl, Stefanie; Striano, Tricia

    2010-01-01

    Recent research has demonstrated that infants' attention towards novel objects is affected by an adult's emotional expression and eye gaze toward the object. The current event-related potential (ERP) study investigated how infants at 3, 6, and 9 months of age process fearful compared to neutral faces looking toward objects or averting gaze away…

  19. Direct Gaze Modulates Face Recognition in Young Infants

    Science.gov (United States)

    Farroni, Teresa; Massaccesi, Stefano; Menon, Enrica; Johnson, Mark H.

    2007-01-01

    From birth, infants prefer to look at faces that engage them in direct eye contact. In adults, direct gaze is known to modulate the processing of faces, including the recognition of individuals. In the present study, we investigate whether direction of gaze has any effect on face recognition in four-month-old infants. Four-month infants were shown…

  20. Non-intrusive eye gaze tracking under natural head movements.

    Science.gov (United States)

    Kim, S; Sked, M; Ji, Q

    2004-01-01

    We propose an eye gaze tracking system under natural head movements. The system consists of one CCD camera and two mirrors. Based on geometric and linear algebra calculations, the mirrors rotate to follow head movements in order to keep the eyes within the view of the camera. Our system allows the subjects head to move 30 cm horizontally and 20 cm vertically, with spatial gaze resolutions about 6 degree and 7 degree, respectively and a frame rate about 10 Hz. We also introduce a hierarchical generalized regression neural networks (H-GRNN) scheme to map eye and mirror parameters to gaze, achieving a gaze estimation accuracy of 92% under head movements. The use of H-GRNN also eliminates the need for personal calibration for new subjects since H-GRNN can generalize. Preliminary experiments show our system is accurate and robust in gaze tracking under large head movements.

  1. Eye Gaze Assistance for a Game-Like Interactive Task

    Directory of Open Access Journals (Sweden)

    Tamás (Tom D. Gedeon

    2008-01-01

    Full Text Available Human beings communicate in abbreviated ways dependent on prior interactions and shared knowledge. Furthermore, humans share information about intentions and future actions using eye gaze. Among primates, humans are unique in the whiteness of the sclera and amount of sclera shown, essential for communication via interpretation of eye gaze. This paper extends our previous work in a game-like interactive task by the use of computerised recognition of eye gaze and fuzzy signature-based interpretation of possible intentions. This extends our notion of robot instinctive behaviour to intentional behaviour. We show a good improvement of speed of response in a simple use of eye gaze information. We also show a significant and more sophisticated use of the eye gaze information, which eliminates the need for control actions on the user's part. We also make a suggestion as to returning visibility of control to the user in these cases.

  2. Differential impact of partial cortical blindness on gaze strategies when sitting and walking - an immersive virtual reality study.

    Science.gov (United States)

    Iorizzo, Dana B; Riley, Meghan E; Hayhoe, Mary; Huxlin, Krystel R

    2011-05-25

    The present experiments aimed to characterize the visual performance of subjects with long-standing, unilateral cortical blindness when walking in a naturalistic, virtual environment. Under static, seated testing conditions, cortically blind subjects are known to exhibit compensatory eye movement strategies. However, they still complain of significant impairment in visual detection during navigation. To assess whether this is due to a change in compensatory eye movement strategy between sitting and walking, we measured eye and head movements in subjects asked to detect peripherally-presented, moving basketballs. When seated, cortically blind subjects detected ∼80% of balls, while controls detected almost all balls. Seated blind subjects did not make larger head movements than controls, but they consistently biased their fixation distribution towards their blind hemifield. When walking, head movements were similar in the two groups, but the fixation bias decreased to the point that fixation distribution in cortically blind subjects became similar to that in controls - with one major exception: at the time of basketball appearance, walking controls looked primarily at the far ground, in upper quadrants of the virtual field of view; cortically blind subjects looked significantly more at the near ground, in lower quadrants of the virtual field. Cortically blind subjects detected only 58% of the balls when walking while controls detected ∼90%. Thus, the adaptive gaze strategies adopted by cortically blind individuals as a compensation for their visual loss are strongest and most effective when seated and stationary. Walking significantly alters these gaze strategies in a way that seems to favor walking performance, but impairs peripheral target detection. It is possible that this impairment underlies the experienced difficulty of those with cortical blindness when navigating in real life.

  3. Gaze following in baboons (Papio anubis): juveniles adjust their gaze and body position to human's head redirections.

    Science.gov (United States)

    Parron, Carole; Meguerditchian, Adrien

    2016-12-01

    Gaze following, the ability to follow the gaze of other individuals, has been widely studied in non-human primate species, mostly in adult individuals. Yet, the literature on gaze following revealed a quite variability across the different findings, some of it might reflect true inter-species differences, while others might be related to methodological differences, or to an underestimation of the factors involved in the expression of gaze following. In the current study, we tested 54 captive olive baboons (Papio anubis), housed in social groups, to assess how juvenile and adult baboons would spontaneously react to a sudden change in the direction of a human experimenter's head. First, our results showed that juveniles, more than adult baboons, co-oriented their gaze with the experimenter's gaze. We also observed a strong habituation effect in adult baboons but not in juveniles, as the adults' response vanished at the second exposure to a change of direction of the experimenter's head. Second, our results showed that juveniles subsequently adopted an original strategy when the experimenter's head indicated some new directions: they reliably adjusted their spatial body position to keep a gaze contact with the experimenter's line of sight. We discussed how the age class and the individual expertise of the baboons could lead to some modulations in terms of attentiveness, motivation, or cognitive abilities, and thus likely influence gaze following.

  4. Silicon Nitride Balls For Cryogenic Bearings

    Science.gov (United States)

    Butner, Myles F.; Ng, Lillian W.

    1990-01-01

    Resistance to wear greater than that of 440C steel. Experiments show lives of ball bearings immersed in liquid nitrogen or liquid oxygen increased significantly when 440C steel balls (running on 440C steel races) replaced by balls of silicon nitride. Developed for use at high temperatures, where lubrication poor or nonexistent. Best wear life of any bearing tested to date and ball material spalls without fracturing. Plans for future tests call for use of liquid oxygen as working fluid.

  5. Vertical bounce of two vertically aligned balls

    Science.gov (United States)

    Cross, Rod

    2007-11-01

    When a tennis ball rests on top of a basketball and both drop to the floor together, the tennis ball is projected vertically at high speed. A mass-spring model of the impact, as well as air track data, suggest that the tennis ball should be projected at relatively low speed. Measurements of the forces on each ball and the bounce of vertically aligned superballs are used to resolve the discrepancy.

  6. Does Ease to Block a Ball Affect Perceived Ball Speed? Examination of Alternative Hypotheses

    Science.gov (United States)

    Witt, Jessica K.; Sugovic, Mila

    2012-01-01

    According to an action-specific account of perception, the perceived speed of a ball can be a function of the ease to block the ball. Balls that are easier to stop look like they are moving slower than balls that are more difficult to stop. This was recently demonstrated with a modified version of the classic computer game Pong (Witt & Sugovic,…

  7. Text Entry by Gazing and Smiling

    Directory of Open Access Journals (Sweden)

    Outi Tuisku

    2013-01-01

    Full Text Available Face Interface is a wearable prototype that combines the use of voluntary gaze direction and facial activations, for pointing and selecting objects on a computer screen, respectively. The aim was to investigate the functionality of the prototype for entering text. First, three on-screen keyboard layout designs were developed and tested (n=10 to find a layout that would be more suitable for text entry with the prototype than traditional QWERTY layout. The task was to enter one word ten times with each of the layouts by pointing letters with gaze and select them by smiling. Subjective ratings showed that a layout with large keys on the edge and small keys near the center of the keyboard was rated as the most enjoyable, clearest, and most functional. Second, using this layout, the aim of the second experiment (n=12 was to compare entering text with Face Interface to entering text with mouse. The results showed that text entry rate for Face Interface was 20 characters per minute (cpm and 27 cpm for the mouse. For Face Interface, keystrokes per character (KSPC value was 1.1 and minimum string distance (MSD error rate was 0.12. These values compare especially well with other similar techniques.

  8. Idea Bank: Wiffle Ball Physics

    Science.gov (United States)

    Lancor, Rachael

    2009-01-01

    Projectile motion, a cornerstone topic of introductory physics, is usually a student's first exposure to the problem-solving techniques used in this subject. Often, this is an inactive learning experience--students work with pencil and paper to read and solve projectile motion problems (e.g., diagrams and descriptions of balls being hit, kicked,…

  9. The correct "ball bearings" data.

    Science.gov (United States)

    Caroni, C

    2002-12-01

    The famous data on fatigue failure times of ball bearings have been quoted incorrectly from Lieblein and Zelen's original paper. The correct data include censored values, as well as non-fatigue failures that must be handled appropriately. They could be described by a mixture of Weibull distributions, corresponding to different modes of failure.

  10. LHC gets the ball rolling

    CERN Multimedia

    2007-01-01

    1. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI).2. During the tests the ball is inserted very carefully into the vacuum chamber.1. Le groupe pluridisciplinaire qui a mené le projet de balle RF pour vérifier les interconnexions avec, de gauche à droite, Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS) et Marek Gasior (AB/BI).2. Lors des tests, la balle est insérée dans la chambre à vide avec beaucoup de précaution.

  11. A Conjecture Concerning Ball Lightning

    CERN Document Server

    Sturrock, P A

    2016-01-01

    There is at present no theory that can explain the curious properties of ball lightning. This suggests that we may not be using the most appropriate concepts. The concept of a 'parallel space' may point the way to a valid theory.

  12. Playing Ball in a Space Station

    Science.gov (United States)

    Simoson, Andrew J.

    2006-01-01

    How does artificial gravity affect the path of a thrown ball? This paper contrasts ball trajectories on the Little Prince's asteroid planet B-612 and Arthur C. Clarke's rotating-drum spacecraft of 2001, and demonstrates curve balls with multiple loops in the latter environment.

  13. Effects of Victim Gaze Behavior and Prior Relationship on Rape Culpability Attributions.

    Science.gov (United States)

    Willis, Cynthia E.; Wrightsman, Lawrence S.

    1995-01-01

    Rape victims' gaze behavior when identifying a defendant and the prior relationship between victim and defendant were examined for effects on rape culpability attributions. In comparison with victims who used gaze maintenance or natural gaze behavior, rape victims' gaze avoidance was perceived as indicative of less truthfulness rather than…

  14. Influence of Eye Gaze on Spoken Word Processing: An ERP Study with Infants

    Science.gov (United States)

    Parise, Eugenio; Handl, Andrea; Palumbo, Letizia; Friederici, Angela D.

    2011-01-01

    Eye gaze is an important communicative signal, both as mutual eye contact and as referential gaze to objects. To examine whether attention to speech versus nonspeech stimuli in 4- to 5-month-olds (n = 15) varies as a function of eye gaze, event-related brain potentials were used. Faces with mutual or averted gaze were presented in combination with…

  15. Interacting with Objects in the Environment by Gaze and Hand Gestures

    DEFF Research Database (Denmark)

    Hales, Jeremy; Mardanbeigi, Diako; Rozado, David

    2013-01-01

    A head-mounted wireless gaze tracker in the form of gaze tracking glasses is used here for continuous and mobile monitoring of a subject's point of regard on the surrounding environment. We combine gaze tracking and hand gesture recognition to allow a subject to interact with objects in the envir......A head-mounted wireless gaze tracker in the form of gaze tracking glasses is used here for continuous and mobile monitoring of a subject's point of regard on the surrounding environment. We combine gaze tracking and hand gesture recognition to allow a subject to interact with objects...... in the environment by gazing at them, and controlling the object using hand gesture commands. The gaze tracking glasses was made from low-cost hardware consisting of a safety glasses' frame and wireless eye tracking and scene cameras. An open source gaze estimation algorithm is used for eye tracking and user's gaze...... in smart environments....

  16. "The Gaze Heuristic:" Biography of an Adaptively Rational Decision Process.

    Science.gov (United States)

    Hamlin, Robert P

    2017-02-21

    This article is a case study that describes the natural and human history of the gaze heuristic. The gaze heuristic is an interception heuristic that utilizes a single input (deviation from a constant angle of approach) repeatedly as a task is performed. Its architecture, advantages, and limitations are described in detail. A history of the gaze heuristic is then presented. In natural history, the gaze heuristic is the only known technique used by predators to intercept prey. In human history the gaze heuristic was discovered accidentally by Royal Air Force (RAF) fighter command just prior to World War II. As it was never discovered by the Luftwaffe, the technique conferred a decisive advantage upon the RAF throughout the war. After the end of the war in America, German technology was combined with the British heuristic to create the Sidewinder AIM9 missile, the most successful autonomous weapon ever built. There are no plans to withdraw it or replace its guiding gaze heuristic. The case study demonstrates that the gaze heuristic is a specific heuristic type that takes a single best input at the best time (take the best(2) ). Its use is an adaptively rational response to specific, rapidly evolving decision environments that has allowed those animals/humans/machines who use it to survive, prosper, and multiply relative to those who do not.

  17. Social decisions affect neural activity to perceived dynamic gaze.

    Science.gov (United States)

    Latinus, Marianne; Love, Scott A; Rossi, Alejandra; Parada, Francisco J; Huang, Lisa; Conty, Laurence; George, Nathalie; James, Karin; Puce, Aina

    2015-11-01

    Gaze direction, a cue of both social and spatial attention, is known to modulate early neural responses to faces e.g. N170. However, findings in the literature have been inconsistent, likely reflecting differences in stimulus characteristics and task requirements. Here, we investigated the effect of task on neural responses to dynamic gaze changes: away and toward transitions (resulting or not in eye contact). Subjects performed, in random order, social (away/toward them) and non-social (left/right) judgment tasks on these stimuli. Overall, in the non-social task, results showed a larger N170 to gaze aversion than gaze motion toward the observer. In the social task, however, this difference was no longer present in the right hemisphere, likely reflecting an enhanced N170 to gaze motion toward the observer. Our behavioral and event-related potential data indicate that performing social judgments enhances saliency of gaze motion toward the observer, even those that did not result in gaze contact. These data and that of previous studies suggest two modes of processing visual information: a 'default mode' that may focus on spatial information; a 'socially aware mode' that might be activated when subjects are required to make social judgments. The exact mechanism that allows switching from one mode to the other remains to be clarified.

  18. Audience gaze while appreciating a multipart musical performance.

    Science.gov (United States)

    Kawase, Satoshi; Obata, Satoshi

    2016-11-01

    Visual information has been observed to be crucial for audience members during musical performances. The present study used an eye tracker to investigate audience members' gazes while appreciating an audiovisual musical ensemble performance, based on evidence of the dominance of musical part in auditory attention when listening to multipart music that contains different melody lines and the joint-attention theory of gaze. We presented singing performances, by a female duo. The main findings were as follows: (1) the melody part (soprano) attracted more visual attention than the accompaniment part (alto) throughout the piece, (2) joint attention emerged when the singers shifted their gazes toward their co-performer, suggesting that inter-performer gazing interactions that play a spotlight role mediated performer-audience visual interaction, and (3) musical part (melody or accompaniment) strongly influenced the total duration of gazes among audiences, while the spotlight effect of gaze was limited to just after the singers' gaze shifts. Copyright © 2016. Published by Elsevier Inc.

  19. Influence of cation disorder on the magnetic properties of ball-milled ilmenite (FeTiO{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Morup, Steen; Rasmussen, Helge K. [Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Brok, Erik [Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Center for Electron Nanoscopy, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Keller, Lukas [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Frandsen, Cathrine, E-mail: fraca@fysik.dtu.dk [Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark)

    2012-09-14

    We have investigated the evolution of crystal structure, cation disorder and magnetic properties of ilmenite (FeTiO{sub 3}) after increasing time of high-energy ball-milling in an inert atmosphere. Refinement of X-ray diffraction data show that the hexagonal crystal structure of ilmenite is maintained after high-energy ball-milling of up to 128 h, but neutron diffraction studies reveal significant cation redistribution of Fe{sup 2+} and Ti{sup 4+} ions in the ball-milled samples. Moessbauer spectroscopy studies show that the magnetic hyperfine field of Fe{sup 2+}, which is around 5 T before ball-milling, increases, and after milling times longer than 4 h a broad distribution of hyperfine fields with values up to around 40 T for Fe{sup 2+} is seen. This can be explained by the cation disorder induced by the ball-milling which affects the orbital contribution to the magnetic hyperfine field. In contrast to some ball-milled spinel ferrites, the Neel temperature of ilmenite is not significantly affected by the cation disorder. -- Highlights: Black-Right-Pointing-Pointer High-energy ball-milling of FeTiO{sub 3} results in cation disorder. Black-Right-Pointing-Pointer The magnetic hyperfine field of {sup 57}Fe is strongly affected by the ball-milling. Black-Right-Pointing-Pointer The Neel temperature of FeTiO{sub 3} is not significantly affected by cation disorder.

  20. Evaluation of an interviewer as a function of interviewer gaze, reinforcement of subject gaze, and interviewer attractiveness.

    Science.gov (United States)

    Kleinke, C L; Staneski, R A; Berger, D E

    1975-01-01

    Male subjects were interviewed by female interviewers who gazed constantly, intermittently, or not at all. Experimental subjects were reinforced with green light feedback whenever they gazed at the interviewers and were punished with red light feedback when they averted gaze for more than 6 seconds. Control subjects received noncontingent green and red light feedback. Although gaze of experimental subjects toward the interviewers was increased significantly, their attitudes toward the interviewers remained the same. This was probably because the subjects did not discriminate that their gazing behavior had changed. Subjects gave the most unfavorable reactions to the nongazing interviewers, rating them as least attractive, giving them the shortest answers, and sitting farthest from them during the debriefing session. Subjects did not discriminate between high and low attractive interviewers, except that the latter were rated disproportionately low on attentiveness if they did not gaze. Interviewers with high rates of talking were preferred over interviewers with low rates of talking. It was concluded that interpersonal attraction is related to gaze and physical attractiveness through a number of mediating variables which will have to be isolated more specifically in future research.

  1. The Mona Lisa effect: neural correlates of centered and off-centered gaze.

    Science.gov (United States)

    Boyarskaya, Evgenia; Sebastian, Alexandra; Bauermann, Thomas; Hecht, Heiko; Tüscher, Oliver

    2015-02-01

    The Mona Lisa effect describes the phenomenon when the eyes of a portrait appear to look at the observer regardless of the observer's position. Recently, the metaphor of a cone of gaze has been proposed to describe the range of gaze directions within which a person feels looked at. The width of the gaze cone is about five degrees of visual angle to either side of a given gaze direction. We used functional magnetic resonance imaging to investigate how the brain regions involved in gaze direction discrimination would differ between centered and decentered presentation positions of a portrait exhibiting eye contact. Subjects observed a given portrait's eyes. By presenting portraits with varying gaze directions-eye contact (0°), gaze at the edge of the gaze cone (5°), and clearly averted gaze (10°), we revealed that brain response to gaze at the edge of the gaze cone was similar to that produced by eye contact and different from that produced by averted gaze. Right fusiform gyrus and right superior temporal sulcus showed stronger activation when the gaze was averted as compared to eye contact. Gaze sensitive areas, however, were not affected by the portrait's presentation location. In sum, although the brain clearly distinguishes averted from centered gaze, a substantial change of vantage point does not alter neural activity, thus providing a possible explanation why the feeling of eye contact is upheld even in decentered stimulus positions. © 2014 Wiley Periodicals, Inc.

  2. Modelling Virtual Camera Behaviour Through Player Gaze

    DEFF Research Database (Denmark)

    Picardi, Andrea; Burelli, Paolo; Yannakakis, Georgios N.

    2012-01-01

    In a three-dimensional virtual environment, aspects such as narrative and interaction largely depend on the placement and animation of the virtual camera. Therefore, virtual camera control plays a critical role in player experience and, thereby, in the overall quality of a computer game. Both game...... industry and game AI research focus on the devel- opment of increasingly sophisticated systems to automate the control of the virtual camera integrating artificial intel- ligence algorithms within physical simulations. However, in both industry and academia little research has been carried out...... on the relationship between virtual camera, game-play and player behaviour. We run a game user experiment to shed some light on this relationship and identify relevant dif- ferences between camera behaviours through different game sessions, playing behaviours and player gaze patterns. Re- sults show that users can...

  3. Microstructural Evolution, Thermodynamics, and Kinetics of Mo-Tm2O3 Powder Mixtures during Ball Milling

    Directory of Open Access Journals (Sweden)

    Yong Luo

    2016-10-01

    Full Text Available The microstructural evolution, thermodynamics, and kinetics of Mo (21 wt % Tm2O3 powder mixtures during ball milling were investigated using X-ray diffraction and transmission electron microscopy. Ball milling induced Tm2O3 to be decomposed and then dissolved into Mo crystal. After 96 h of ball milling, Tm2O3 was dissolved completely and the supersaturated nanocrystalline solid solution of Mo (Tm, O was obtained. The Mo lattice parameter increased with increasing ball-milling time, opposite for the Mo grain size. The size and lattice parameter of Mo grains was about 8 nm and 0.31564 nm after 96 h of ball milling, respectively. Ball milling induced the elements of Mo, Tm, and O to be distributed uniformly in the ball-milled particles. Based on the semi-experimental theory of Miedema, a thermodynamic model was developed to calculate the driving force of phase evolution. There was no chemical driving force to form a crystal solid solution of Tm atoms in Mo crystal or an amorphous phase because the Gibbs free energy for both processes was higher than zero. For Mo (21 wt % Tm2O3, it was mechanical work, not the negative heat of mixing, which provided the driving force to form a supersaturated nanocrystalline Mo (Tm, O solid solution.

  4. Discriminating between intentional and unintentional gaze fixation using multimodal-based fuzzy logic algorithm for gaze tracking system with NIR camera sensor

    Science.gov (United States)

    Naqvi, Rizwan Ali; Park, Kang Ryoung

    2016-06-01

    Gaze tracking systems are widely used in human-computer interfaces, interfaces for the disabled, game interfaces, and for controlling home appliances. Most studies on gaze detection have focused on enhancing its accuracy, whereas few have considered the discrimination of intentional gaze fixation (looking at a target to activate or select it) from unintentional fixation while using gaze detection systems. Previous research methods based on the use of a keyboard or mouse button, eye blinking, and the dwell time of gaze position have various limitations. Therefore, we propose a method for discriminating between intentional and unintentional gaze fixation using a multimodal fuzzy logic algorithm applied to a gaze tracking system with a near-infrared camera sensor. Experimental results show that the proposed method outperforms the conventional method for determining gaze fixation.

  5. Exact Wavelets on the Ball

    CERN Document Server

    Leistedt, B

    2012-01-01

    We develop an exact wavelet transform on the three-dimensional ball (i.e. on the solid sphere), which we name the flaglet transform. For this purpose we first construct an exact harmonic transform on the radial line using damped Laguerre polynomials and develop a corresponding quadrature rule. Combined with the spherical harmonic transform, this approach leads to a sampling theorem on the ball and a novel three-dimensional decomposition which we call the Fourier-Laguerre transform. We relate this new transform to the well-known Fourier-Bessel decomposition and show that band-limitness in the Fourier-Laguerre basis is a sufficient condition to compute the Fourier-Bessel decomposition exactly. We then construct the flaglet transform on the ball through a harmonic tiling, which is exact thanks to the exactness of the Fourier-Laguerre transform (from which the name flaglets is coined). The corresponding wavelet kernels have compact localisation properties in real and harmonic space and their angular aperture is i...

  6. Studies On Falling Ball Viscometry

    CERN Document Server

    Singh, Amit Vikram; Gupta-Bhaya, Pinaki

    2012-01-01

    A new method of accurate calculation of the coefficient of viscosity of a test liquid from experimentally measured terminal velocity of a ball falling in the test liquid contained in a narrow tube is described. The calculation requires the value of a multiplicative correction factor to the apparent coefficient of viscosity calculated by substitution of terminal velocity of the falling ball in Stokes formula. This correction factor, the so-called viscosity ratio, a measure of deviation from Stokes limit, arises from non-vanishing values of the Reynolds number and the ball/tube radius ratio. The method, valid over a very wide range of Reynolds number, is based on the recognition of a relationship between two measures of wall effect, the more widely investigated velocity ratio, defined as the ratio of terminal velocity in a confined medium to that in a boundless medium and viscosity ratio. The calculation uses two recently published correlation formulae based on extensive experimental results on terminal velocit...

  7. WOMAN AS OBJECT OF MALE GAZE IN SOME WORKS OF ...

    African Journals Online (AJOL)

    Nkiruka

    I also take on the argument that some Nigerian male artists‟ perception of .... and such genre are observable in private spheres such as hotel rooms and ..... gaze, A thesis submitted to the Graduate College of Bowling Green, May 2006.

  8. Pupil dilation as an index of preferred mutual gaze duration

    National Research Council Canada - National Science Library

    Binetti, Nicola; Harrison, Charlotte; Coutrot, Antoine; Johnston, Alan; Mareschal, Isabelle

    2016-01-01

    .... Deviations from this pattern of gazing behaviour generally make us feel uncomfortable and are a defining characteristic of clinical conditions such as autism or schizophrenia, yet it is unclear what...

  9. The Politics of the Gaze Foucault, Lacan and Zizek

    Directory of Open Access Journals (Sweden)

    Henry Krips

    2010-03-01

    Full Text Available Joan Copjec accuses orthodox film theory of misrepresenting the Lacanian gaze by assimilating it to Foucauldian panopticon (Copjec 1994: 18-19. Although Copjec is correct that orthodox film theory misrepresents the Lacanian gaze, she, in turn, misrepresents Foucault by choosing to focus exclusively upon those as-pects of his work on the panopticon that have been taken up by orthodox film the-ory (Copjec 1994: 4. In so doing, I argue, Copjec misses key parallels between the Lacanian and Foucauldian concepts of the gaze. More than a narrow academic dispute about how to read Foucault and Lacan, this debate has wider political sig-nificance. In particular, using Slavoj Zizek's work, I show that a correct account of the panoptic gaze leads us to rethink the question of how to oppose modern techniques of surveillance.

  10. Gazing behavior and coordination during piano duo performance.

    Science.gov (United States)

    Kawase, Satoshi

    2014-02-01

    This study was designed to investigate the roles of gazing behavior during piano duo performance by highlighting coordination among performers. Experiment 1 was conducted under four conditions: invisible, only the body visible, only the head visible, and face -to -face. Experiment 2 was conducted under three conditions: invisible, only the movable head visible, and only the fixed head visible. In both experiments, performers looked toward each other just before temporal changes during coordination moments, which improved synchronization accuracy. The results also showed that gazing without movement cues to some extent facilitated synchronization, although asynchrony was greater under the restricted- movement condition than under the free- movement condition. The following results were obtained:(1) Mutual gaze is important for reducing timing lag between performers. (2) Mutual gaze modulates remarkable and arbitrary temporal expressions, such as fermata. (3) Performers may utilize movements as visual cues for strict synchronization.

  11. Latvian government in double jeopardy with EU, Latvijas Gaze

    Index Scriptorium Estoniae

    2005-01-01

    Läti soovib saada Euroopa Komisjonilt ajapikendust gaasituru liberaliseerimiseks 2010. aastani ning lubab sel juhul sõlmida Latvijas Gaze'ga kokkuleppe, et viimane loobuks gaasitarnete ainuõigusest Lätis

  12. Ball Screw Actuator Including a Stop with an Integral Guide

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Perek, John (Inventor); Geck, Kellan (Inventor)

    2015-01-01

    An actuator includes a housing assembly, a ball nut, a ball screw, and a ball screw stop. The ball nut is rotationally mounted in the housing assembly, is adapted to receive an input torque, and is configured, upon receipt thereof, to rotate and supply a drive force. The ball screw is mounted within the housing assembly and extends through the ball nut. The ball screw has a first end and a second end, and is coupled to receive the drive force from the ball nut. The ball screw is configured, upon receipt of the drive force, to selectively translate between a stow position and a deploy position. The ball screw stop is mounted on the ball screw to translate therewith and is configured to at selectively engage the housing assembly while the ball screw is translating, and engage the ball nut when the ball screw is in the deploy position.

  13. How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality.

    Science.gov (United States)

    McLeod, Peter; Reed, Nick; Gilson, Stuart; Glennerster, Andrew

    2008-06-01

    We measured the movements of soccer players heading a football in a fully immersive virtual reality environment. In mid-flight the ball's trajectory was altered from its normal quasi-parabolic path to a linear one, producing a jump in the rate of change of the angle of elevation of gaze (alpha) from player to ball. One reaction time later the players adjusted their speed so that the rate of change of alpha increased when it had been reduced and reduced it when it had been increased. Since the result of the player's movement was to regain a value of the rate of change close to that before the disturbance, the data suggest that the players have an expectation of, and memory for, the pattern that the rate of change of alpha will follow during the flight. The results support the general claim that players intercepting balls use servo control strategies and are consistent with the particular claim of Optic Acceleration Cancellation theory that the servo strategy is to allow alpha to increase at a steadily decreasing rate.

  14. Culture, gaze and the neural processing of fear expressions

    OpenAIRE

    2009-01-01

    The direction of others’ eye gaze has important influences on how we perceive their emotional expressions. Here, we examined differences in neural activation to direct- versus averted-gaze fear faces as a function of culture of the participant (Japanese versus US Caucasian), culture of the stimulus face (Japanese versus US Caucasian), and the relation between the two. We employed a previously validated paradigm to examine differences in neural activation in response to rapidly presented direc...

  15. Enhancing Sensorimotor Activity by Controlling Virtual Objects with Gaze

    OpenAIRE

    2015-01-01

    This fMRI work studies brain activity of healthy volunteers who manipulated a virtual object in the context of a digital game by applying two different control methods: using their right hand or using their gaze. The results show extended activations in sensorimotor areas, not only when participants played in the traditional way (using their hand) but also when they used their gaze to control the virtual object. Furthermore, with the exception of the primary motor cortex, regional motor activ...

  16. Segmentation of object-based video of gaze communication

    DEFF Research Database (Denmark)

    Aghito, Shankar Manuel; Stegmann, Mikkel Bille; Forchhammer, Søren

    2005-01-01

    Aspects of video communication based on gaze interaction are considered. The overall idea is to use gaze interaction to control video, e.g. for video conferencing. Towards this goal, animation of a facial mask is demonstrated. The animation is based on images using Active Appearance Models (AAM......). Good quality reproduction of (low-resolution) coded video of an animated facial mask as low as 10-20 kbit/s using MPEG-4 object based video is demonstated....

  17. Using Gaze Patterns to Predict Task Intent in Collaboration

    Directory of Open Access Journals (Sweden)

    Chien-Ming eHuang

    2015-07-01

    Full Text Available In everyday interactions, humans naturally exhibit behavioral cues, such as gaze and head movements, that signal their intentions while interpreting the behavioral cues of others to predict their intentions. Such intention prediction enables each partner to adapt their behaviors to the intent of others, serving a critical role in joint action where parties work together to achieve a common goal. Among behavioral cues, eye gaze is particularly important in understanding a person's attention and intention. In this work, we seek to quantify how gaze patterns may indicate a person's intention. Our investigation was contextualized in a dyadic sandwich-making scenario in which a worker'' prepared a sandwich by adding ingredients requested by a customer.'' In this context, we investigated the extent to which the customers' gaze cues serve as predictors of which ingredients they intend to request. Predictive features were derived to represent characteristics of the customers' gaze patterns. We developed a support vector machine-based (SVM-based model that achieved 76% accuracy in predicting the customers' intended requests based solely on gaze features. Moreover, the predictor made correct predictions approximately 1.8 seconds before the spoken request from the customer. We further analyzed several episodes of interactions from our data to develop a deeper understanding of the scenarios where our predictor succeeded and failed in making correct predictions. These analyses revealed additional gaze patterns that may be leveraged to improve intention prediction. This work highlights gaze cues as a significant resource for understanding human intentions and informs the design of real-time recognizers of user intention for intelligent systems, such as assistive robots and ubiquitous devices, that may enable more complex capabilities and improved user experience.

  18. Culture, gaze and the neural processing of fear expressions.

    Science.gov (United States)

    Adams, Reginald B; Franklin, Robert G; Rule, Nicholas O; Freeman, Jonathan B; Kveraga, Kestutis; Hadjikhani, Nouchine; Yoshikawa, Sakiko; Ambady, Nalini

    2010-06-01

    The direction of others' eye gaze has important influences on how we perceive their emotional expressions. Here, we examined differences in neural activation to direct- versus averted-gaze fear faces as a function of culture of the participant (Japanese versus US Caucasian), culture of the stimulus face (Japanese versus US Caucasian), and the relation between the two. We employed a previously validated paradigm to examine differences in neural activation in response to rapidly presented direct- versus averted-fear expressions, finding clear evidence for a culturally determined role of gaze in the processing of fear. Greater neural responsivity was apparent to averted- versus direct-gaze fear in several regions related to face and emotion processing, including bilateral amygdalae, when posed on same-culture faces, whereas greater response to direct- versus averted-gaze fear was apparent in these same regions when posed on other-culture faces. We also found preliminary evidence for intercultural variation including differential responses across participants to Japanese versus US Caucasian stimuli, and to a lesser degree differences in how Japanese and US Caucasian participants responded to these stimuli. These findings reveal a meaningful role of culture in the processing of eye gaze and emotion, and highlight their interactive influences in neural processing.

  19. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements.

    Science.gov (United States)

    Kreysa, Helene; Kessler, Luise; Schweinberger, Stefan R

    2016-01-01

    A speaker's gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., "sniffer dogs cannot smell the difference between identical twins"). Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted) gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze.

  20. Gaze Stripes: Image-Based Visualization of Eye Tracking Data.

    Science.gov (United States)

    Kurzhals, Kuno; Hlawatsch, Marcel; Heimerl, Florian; Burch, Michael; Ertl, Thomas; Weiskopf, Daniel

    2016-01-01

    We present a new visualization approach for displaying eye tracking data from multiple participants. We aim to show the spatio-temporal data of the gaze points in the context of the underlying image or video stimulus without occlusion. Our technique, denoted as gaze stripes, does not require the explicit definition of areas of interest but directly uses the image data around the gaze points, similar to thumbnails for images. A gaze stripe consists of a sequence of such gaze point images, oriented along a horizontal timeline. By displaying multiple aligned gaze stripes, it is possible to analyze and compare the viewing behavior of the participants over time. Since the analysis is carried out directly on the image data, expensive post-processing or manual annotation are not required. Therefore, not only patterns and outliers in the participants' scanpaths can be detected, but the context of the stimulus is available as well. Furthermore, our approach is especially well suited for dynamic stimuli due to the non-aggregated temporal mapping. Complementary views, i.e., markers, notes, screenshots, histograms, and results from automatic clustering, can be added to the visualization to display analysis results. We illustrate the usefulness of our technique on static and dynamic stimuli. Furthermore, we discuss the limitations and scalability of our approach in comparison to established visualization techniques.

  1. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements

    Science.gov (United States)

    Kessler, Luise; Schweinberger, Stefan R.

    2016-01-01

    A speaker’s gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., “sniffer dogs cannot smell the difference between identical twins”). Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted) gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze. PMID:27643789

  2. EMOTIONAL MODULATION OF ATTENTION ORIENTING BY GAZE VARIES WITH DYNAMIC CUE SEQUENCE

    Science.gov (United States)

    Lassalle, Amandine; Itier, Roxane J.

    2017-01-01

    Recent gaze cueing studies using dynamic cue sequences have reported increased attention orienting by gaze with faces expressing fear, surprise or anger. Here, we investigated whether the type of dynamic cue sequence used impacted the magnitude of this effect. When the emotion was expressed before or concurrently with gaze shift, no modulation of gaze-oriented attention by emotion was seen. In contrast, when the face cue averted gaze before expressing an emotion (as if reacting to the object after first localizing it), the gaze orienting effect was clearly increased for fearful, surprised and angry faces compared to neutral faces. Thus, the type of dynamic sequence used, and in particular the order in which the gaze shift and the facial expression are presented, modulate gaze-oriented attention, with maximal modulation seen when the expression of emotion follows gaze shift.

  3. Fluid Mechanics of Cricket and Tennis Balls

    Science.gov (United States)

    Mehta, Rabindra D.

    2009-11-01

    Aerodynamics plays a prominent role in defining the flight of a ball that is struck or thrown through the air in almost all ball sports. The main interest is in the fact that the ball can often deviate from its initial straight path, resulting in a curved, or sometimes an unpredictable, flight path. It is particularly fascinating that that not all the parameters that affect the flight of a ball are always under human influence. Lateral deflection in flight, commonly known as swing, swerve or curve, is well recognized in cricket and tennis. In tennis, the lateral deflection is produced by spinning the ball about an axis perpendicular to the line of flight, which gives rise to what is commonly known as the Magnus effect. It is now well recognized that the aerodynamics of sports balls are strongly dependent on the detailed development and behavior of the boundary layer on the ball's surface. A side force, which makes a ball curve through the air, can also be generated in the absence of the Magnus effect. In one of the cricket deliveries, the ball is released with the seam angled, which trips the laminar boundary layer into a turbulent state on that side. The turbulent boundary layer separates relatively late compared to the laminar layer on the other side, thereby creating a pressure difference and hence side force. The fluid mechanics of a cricket ball become very interesting at the higher Reynolds numbers and this will be discussed in detail. Of all the round sports balls, a tennis ball has the highest drag coefficient. This will be explained in terms of the contribution of the ``fuzz" drag and how that changes with Reynolds number and ball surface wear. It is particularly fascinating that, purely through historical accidents, small disturbances on the ball surface, such as the stitching on cricket balls and the felt cover on tennis balls are all about the right size to affect boundary layer transition and development in the Reynolds numbers of interest. The fluid

  4. Judgments at Gaze Value: Gaze Cuing in Banner Advertisements, Its Effect on Attention Allocation and Product Judgments.

    Science.gov (United States)

    Palcu, Johanna; Sudkamp, Jennifer; Florack, Arnd

    2017-01-01

    Banner advertising is a popular means of promoting products and brands online. Although banner advertisements are often designed to be particularly attention grabbing, they frequently go unnoticed. Applying an eye-tracking procedure, the present research aimed to (a) determine whether presenting human faces (static or animated) in banner advertisements is an adequate tool for capturing consumers' attention and thus overcoming the frequently observed phenomenon of banner blindness, (b) to examine whether the gaze of a featured face possesses the ability to direct consumers' attention toward specific elements (i.e., the product) in an advertisement, and (c) to establish whether the gaze direction of an advertised face influences consumers subsequent evaluation of the advertised product. We recorded participants' eye gaze while they viewed a fictional online shopping page displaying banner advertisements that featured either no human face or a human face that was either static or animated and involved different gaze directions (toward or away from the advertised product). Moreover, we asked participants to subsequently evaluate a set of products, one of which was the product previously featured in the banner advertisement. Results showed that, when advertisements included a human face, participants' attention was more attracted by and they looked longer at animated compared with static banner advertisements. Moreover, when a face gazed toward the product region, participants' likelihood of looking at the advertised product increased regardless of whether the face was animated or not. Most important, gaze direction influenced subsequent product evaluations; that is, consumers indicated a higher intention to buy a product when it was previously presented in a banner advertisement that featured a face that gazed toward the product. The results suggest that while animation in banner advertising constitutes a salient feature that captures consumers' visual attention, gaze

  5. Judgments at Gaze Value: Gaze Cuing in Banner Advertisements, Its Effect on Attention Allocation and Product Judgments

    Directory of Open Access Journals (Sweden)

    Johanna Palcu

    2017-06-01

    Full Text Available Banner advertising is a popular means of promoting products and brands online. Although banner advertisements are often designed to be particularly attention grabbing, they frequently go unnoticed. Applying an eye-tracking procedure, the present research aimed to (a determine whether presenting human faces (static or animated in banner advertisements is an adequate tool for capturing consumers’ attention and thus overcoming the frequently observed phenomenon of banner blindness, (b to examine whether the gaze of a featured face possesses the ability to direct consumers’ attention toward specific elements (i.e., the product in an advertisement, and (c to establish whether the gaze direction of an advertised face influences consumers subsequent evaluation of the advertised product. We recorded participants’ eye gaze while they viewed a fictional online shopping page displaying banner advertisements that featured either no human face or a human face that was either static or animated and involved different gaze directions (toward or away from the advertised product. Moreover, we asked participants to subsequently evaluate a set of products, one of which was the product previously featured in the banner advertisement. Results showed that, when advertisements included a human face, participants’ attention was more attracted by and they looked longer at animated compared with static banner advertisements. Moreover, when a face gazed toward the product region, participants’ likelihood of looking at the advertised product increased regardless of whether the face was animated or not. Most important, gaze direction influenced subsequent product evaluations; that is, consumers indicated a higher intention to buy a product when it was previously presented in a banner advertisement that featured a face that gazed toward the product. The results suggest that while animation in banner advertising constitutes a salient feature that captures consumers

  6. Judgments at Gaze Value: Gaze Cuing in Banner Advertisements, Its Effect on Attention Allocation and Product Judgments

    Science.gov (United States)

    Palcu, Johanna; Sudkamp, Jennifer; Florack, Arnd

    2017-01-01

    Banner advertising is a popular means of promoting products and brands online. Although banner advertisements are often designed to be particularly attention grabbing, they frequently go unnoticed. Applying an eye-tracking procedure, the present research aimed to (a) determine whether presenting human faces (static or animated) in banner advertisements is an adequate tool for capturing consumers’ attention and thus overcoming the frequently observed phenomenon of banner blindness, (b) to examine whether the gaze of a featured face possesses the ability to direct consumers’ attention toward specific elements (i.e., the product) in an advertisement, and (c) to establish whether the gaze direction of an advertised face influences consumers subsequent evaluation of the advertised product. We recorded participants’ eye gaze while they viewed a fictional online shopping page displaying banner advertisements that featured either no human face or a human face that was either static or animated and involved different gaze directions (toward or away from the advertised product). Moreover, we asked participants to subsequently evaluate a set of products, one of which was the product previously featured in the banner advertisement. Results showed that, when advertisements included a human face, participants’ attention was more attracted by and they looked longer at animated compared with static banner advertisements. Moreover, when a face gazed toward the product region, participants’ likelihood of looking at the advertised product increased regardless of whether the face was animated or not. Most important, gaze direction influenced subsequent product evaluations; that is, consumers indicated a higher intention to buy a product when it was previously presented in a banner advertisement that featured a face that gazed toward the product. The results suggest that while animation in banner advertising constitutes a salient feature that captures consumers’ visual

  7. Coefficient of Restitution of Wet Tennis Balls

    Directory of Open Access Journals (Sweden)

    Eugene Jang

    2014-12-01

    Full Text Available The coefficient of restitution of a damp tennis ball is of interest to tennis players. Using a spray bottle, water was added to a tennis ball and the mass of water on the wet ball was determined. The ball was then dropped from a fixed height of 0.86 m. The motion was recorded with a video camera and the bounce height was measured. Using the bounce height and the original height, the coefficient of restitution for that mass of added water was determined. The research found the mass of water added to the tennis ball to have a negatively linear relationship with the coefficient of restitution of the tennis ball.

  8. Coefficient of Restitution of Wet Tennis Balls

    Directory of Open Access Journals (Sweden)

    Eugene Jang

    2014-01-01

    Full Text Available The coefficient of restitution of a damp tennis ball is of interest to tennis players. Using a spray bottle, water was added to a tennis ball and the mass of water on the wet ball was determined. The ball was then dropped from a fixed height of 0.86 m. The motion was recorded with a video camera and the bounce height was measured. Using the bounce height and the original height, the coefficient of restitution for that mass of added water was determined. The research found the mass of water added to the tennis ball to have a negatively linear relationship with the coefficient of restitution of the tennis ball.

  9. Gaze maintenance and autism spectrum disorder.

    Science.gov (United States)

    Kaye, Leah; Kurtz, Marie; Tierney, Cheryl; Soni, Ajay; Augustyn, Marilyn

    2014-01-01

    were equal and reactive without afferent pupillary defect, and normal visual tracking as assessed through pursuit and saccades. There were some head jerking motions observed which were not thought to be part of Chase's attempts to view objects. Gaze impersistence was noted, although it was not clear if this was due to a lack of attention or a true inability to maintain a gaze in the direction instructed. On review of the school's speech and language report, they state that he is >90% intelligible. He has occasional lip trills. Testing with the Clinical Evaluation of Language Fundamentals shows mild delays in receptive language, especially those that require visual attention. Verbal Motor Production Assessment for Children reveals focal oromotor control and sequencing skills that are below average, with groping when asked to imitate single oromotor nonspeech movements and sequenced double oromotor nonspeech movements. At 5½ years, he returns for follow-up, and he is outgoing and imaginative, eager to play and socialize. He makes eye contact but does not always maintain it. He asks and responds to questions appropriately, and he is able to follow verbal directions and verbal redirection. He is very interested in Toy Story characters but willing to share them and plays with other toys. Chase's speech has predictable, easy to decode sound substitutions. On interview with him, you feel that he has borderline cognitive abilities. He also demonstrates good eye contact but lack of visual gaze maintenance; this is the opposite of the pattern you are accustomed to in patients with autism spectrum disorder. What do you do next?

  10. Perceptual Training in Beach Volleyball Defence: Different Effects of Gaze-Path Cueing on Gaze and Decision-Making

    Directory of Open Access Journals (Sweden)

    André eKlostermann

    2015-12-01

    Full Text Available For perceptual-cognitive skill training, a variety of intervention methods has been proposed, including the so-called colour-cueing method which aims on superior gaze-path learning by applying visual markers. However, recent findings challenge this method, especially, with regards to its actual effects on gaze behaviour. Consequently, after a preparatory study on the identification of appropriate visual cues for life-size displays, a perceptual-training experiment on decision-making in beach volleyball was conducted, contrasting two cueing interventions (functional vs. dysfunctional gaze path with a conservative control condition (anticipation-related instructions. Gaze analyses revealed learning effects for the dysfunctional group only. Regarding decision-making, all groups showed enhanced performance with largest improvements for the control group followed by the functional and the dysfunctional group. Hence, the results confirm cueing effects on gaze behaviour, but they also question its benefit for enhancing decision-making. However, before completely denying the method’s value, optimisations should be checked regarding, for instance, cueing-pattern characteristics and gaze-related feedback.

  11. Perceptual Training in Beach Volleyball Defence: Different Effects of Gaze-Path Cueing on Gaze and Decision-Making.

    Science.gov (United States)

    Klostermann, André; Vater, Christian; Kredel, Ralf; Hossner, Ernst-Joachim

    2015-01-01

    For perceptual-cognitive skill training, a variety of intervention methods has been proposed, including the so-called "color-cueing method" which aims on superior gaze-path learning by applying visual markers. However, recent findings challenge this method, especially, with regards to its actual effects on gaze behavior. Consequently, after a preparatory study on the identification of appropriate visual cues for life-size displays, a perceptual-training experiment on decision-making in beach volleyball was conducted, contrasting two cueing interventions (functional vs. dysfunctional gaze path) with a conservative control condition (anticipation-related instructions). Gaze analyses revealed learning effects for the dysfunctional group only. Regarding decision-making, all groups showed enhanced performance with largest improvements for the control group followed by the functional and the dysfunctional group. Hence, the results confirm cueing effects on gaze behavior, but they also question its benefit for enhancing decision-making. However, before completely denying the method's value, optimisations should be checked regarding, for instance, cueing-pattern characteristics and gaze-related feedback.

  12. Influence of cation disorder on the magnetic properties of ball-milled ilmenite (FeTiO3)

    DEFF Research Database (Denmark)

    Mørup, Steen; Rasmussen, Helge Kildahl; Brok, Erik;

    2012-01-01

    We have investigated the evolution of crystal structure, cation disorder and magnetic properties of ilmenite (FeTiO3) after increasing time of high-energy ball-milling in an inert atmosphere. Refinement of X-ray diffraction data show that the hexagonal crystal structure of ilmenite is maintained ...

  13. Multifractal properties of ball milling dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Budroni, M. A., E-mail: mabudroni@uniss.it; Pilosu, V.; Rustici, M. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100 (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123 (Italy)

    2014-06-15

    This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.

  14. Multifractal properties of ball milling dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Budroni, M. A., E-mail: mabudroni@uniss.it; Pilosu, V.; Rustici, M. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100 (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123 (Italy)

    2014-06-15

    This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.

  15. From Schwinger Balls to Curved Space

    CERN Document Server

    Allahbakhshi, Davood

    2016-01-01

    It is shown that the Reissner-Nordstrom black hole is also a gravitational Schwinger ball. It is also shown that both massless and massive-particle gravitational Schwinger balls are thermodynamic systems by deriving the first law of thermodynamics for them. Inconsistency between classical geometrical and microscopic definitions of the horizon is discussed. We propose a new metric, more consistent with microscopic picture of black hole, as gravitational Schwinger ball, by speculations. It has some interesting features.

  16. Ball Bearing Stacking Automation System

    Directory of Open Access Journals (Sweden)

    Shafeequerrahman S . Ahmed

    2013-01-01

    Full Text Available This document is an effort to introduce the concept of automation in small scale industries and or small workshops that are involved in the manufacturing of small objects such as nuts, bolts and ball bearing in this case. This an electromechanical system which includes certain mechanical parts that involves one base stand on which one vertical metallic frame is mounted and hinged to this vertical stand is an in humanized effort seems inadequate in this era making necessary the use of Electronics, Computer in the manufacturing processes leading to the concept of Automated Manufacturing System (AMS.The ball bearing stack automation is an effort in this regard. In our project we go for stack automation for any object for example a ball bearing, be that is still a manual system there. It will be microcontroller based project control system equipped with microcontroller 89C51 from any manufacturer like Atmel or Philips. This could have been easily implemented if a PLC could be used for manufacturing the staking unit but I adopted the microcontroller based system so that some more modification in the system can be effected at will as to use the same hardware .Although a very small object i.e. ball bearig or small nut and fixture will be tried to be stacked, the system with more precision and more power handling capacity could be built for various requirements of the industry. For increasing more control capacity, we can use another module of this series. When the bearing is ready, it will be sent for packing. This is sensed by an inductive sensor. The output will be proceeds by PLC and microcontroller card which will be driving the assembly in order to put it into pads or flaps. This project will also count the total number of bearings to be packed and will display it on a LCD for real time reference and a provision is made using a higher level language using hyper terminal of the computer

  17. Two-ball Newton's cradle.

    Science.gov (United States)

    Glendinning, Paul

    2011-12-01

    Newton's cradle for two balls with Hertzian interactions is considered as a hybrid system, and this makes it possible to derive return maps for the motion between collisions in an exact form despite the fact that the three-halves interaction law cannot be solved in closed form. The return maps depend on a constant whose value can only be determined numerically, but solutions can be written down explicitly in terms of this parameter, and we compare this with the results of simulations. The results are in fact independent of the details of the interaction potential.

  18. Left atrial ball valve thrombus

    Directory of Open Access Journals (Sweden)

    R. Balaji

    2013-10-01

    Full Text Available "Ball valve thrombus" which is a spherical free floating clot in left atrium is an often quoted, but uncommonly encountered complication in patients with severe mitral stenosis of rheumatic origin, who are in atrial fibrillation. We describe the case of a 31-year-old lady with rheumatic heart disease, severe mitral stenosis and moderately severe aortic stenosis who had undergone closed mitral valvotomy 13 years ago. The patient presented with an episode of non-exertional syncope and breathlessness on exertion of 6 months duration and was in normal sinus rhythm. Echocardiography facilitated ante-mortem diagnosis and prompt institution of surgery was life saving.

  19. The Soccer-Ball Problem

    Science.gov (United States)

    Hossenfelder, Sabine

    2014-07-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

  20. The Soccer-ball Problem

    CERN Document Server

    Hossenfelder, S

    2014-01-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. Motivated by Loop Quantum Gravity, this modified Lorentz-symmetry is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the "soccer-ball problem." This article briefly reviews the problem and the status of existing solution attempts.

  1. Transperance Me I Want to be Visible: Gay Gaze in Tom Ford’s film A Single Man

    Directory of Open Access Journals (Sweden)

    Selen Gokcem

    2012-04-01

    Full Text Available Classic gaze theory that was underlined by Laura Mulvey in 1975 which claims the male gaze objectifies woman and turns the woman into a sex object, is lack in the explaining gaze from man to man. In Tom Ford’s A Single Man the gaze is used from man to man different from man to woman and it is not perceived as something negative. By providing a queer gaze analysis, this article will show how homosexual people live their intimate feelings by gaze and how gay gaze can be different from the classic gaze in a way that it does not reduces the other one in an interior position.

  2. Noncontact binocular eye-gaze tracking for point-of-gaze estimation in three dimensions.

    Science.gov (United States)

    Hennessey, Craig; Lawrence, Peter

    2009-03-01

    Binocular eye-gaze tracking can be used to estimate the point-of-gaze (POG) of a subject in real-world 3-D space using the vergence of the eyes. In this paper, a novel noncontact model-based technique for 3-D POG estimation is presented. The noncontact system allows people to select real-world objects in 3-D physical space using their eyes, without the need for head-mounted equipment. Remote 3-D POG estimation may be especially useful for persons with quadriplegia or Amyotrophic Lateral Sclerosis. It would also enable a user to select 3-D points in space generated by 3-D volumetric displays, with potential applications to medical imaging and telesurgery. Using a model-based POG estimation algorithm allows for free head motion and a single stage of calibration. It is shown that an average accuracy of 3.93 cm was achieved over a workspace volume of 30 x 23 x 25 cm (W x H x D) with a maximum latency of 1.5 s due to the digital filtering employed. The users were free to naturally move and reorient their heads while operating the system, within an allowable headspace of 3 cm x 9 cm x 14 cm.

  3. PREPARING NANO-CRYSTALLINE La DOPED WC/Co POWDER BY HIGH ENERGY BALL MILLING

    Institute of Scientific and Technical Information of China (English)

    S. Liu; D.Q. Yi; Y.X. Li; D. Zou

    2002-01-01

    The La doped WC/Co powder was prepared by high energy ball milling. The changesof crystal structure, micrograph and defect of the powder were investigated by means ofXRD (X-ray diffraction), SEM (scanning electron microscope) and DTA (differentialthermal analysis). The results show that adding trace La element into carbides iseffective to minish the grain size of WC/Co powder. The La doped carbides powderwith grain size of 30nm can be obtained after 1Oh ball milling. The XRD peak of Cophase disappeared after 20h ball milling, which indicated solid solution (or secondarysolid solution) of Co phase in WC phase. The La doped powder with grain size of1Ohm is obtained after 30h ball milling. A peak of heat release at the temperatureof 470℃ was emerged in DTA curve within the range of heating temperature, whichshowed that the crystal structure relaxation of the powder appeared in the process ofhigh energy ball milling. After consolidated the La doped WC/Co alloy by high energyball milling exhibits ultra-fine grain Sizes and better mechanical properties.

  4. A comparison of facial color pattern and gazing behavior in canid species suggests gaze communication in gray wolves (Canis lupus.

    Directory of Open Access Journals (Sweden)

    Sayoko Ueda

    Full Text Available As facial color pattern around the eyes has been suggested to serve various adaptive functions related to the gaze signal, we compared the patterns among 25 canid species, focusing on the gaze signal, to estimate the function of facial color pattern in these species. The facial color patterns of the studied species could be categorized into the following three types based on contrast indices relating to the gaze signal: A-type (both pupil position in the eye outline and eye position in the face are clear, B-type (only the eye position is clear, and C-type (both the pupil and eye position are unclear. A-type faces with light-colored irises were observed in most studied species of the wolf-like clade and some of the red fox-like clade. A-type faces tended to be observed in species living in family groups all year-round, whereas B-type faces tended to be seen in solo/pair-living species. The duration of gazing behavior during which the facial gaze-signal is displayed to the other individual was longest in gray wolves with typical A-type faces, of intermediate length in fennec foxes with typical B-type faces, and shortest in bush dogs with typical C-type faces. These results suggest that the facial color pattern of canid species is related to their gaze communication and that canids with A-type faces, especially gray wolves, use the gaze signal in conspecific communication.

  5. A comparison of facial color pattern and gazing behavior in canid species suggests gaze communication in gray wolves (Canis lupus).

    Science.gov (United States)

    Ueda, Sayoko; Kumagai, Gaku; Otaki, Yusuke; Yamaguchi, Shinya; Kohshima, Shiro

    2014-01-01

    As facial color pattern around the eyes has been suggested to serve various adaptive functions related to the gaze signal, we compared the patterns among 25 canid species, focusing on the gaze signal, to estimate the function of facial color pattern in these species. The facial color patterns of the studied species could be categorized into the following three types based on contrast indices relating to the gaze signal: A-type (both pupil position in the eye outline and eye position in the face are clear), B-type (only the eye position is clear), and C-type (both the pupil and eye position are unclear). A-type faces with light-colored irises were observed in most studied species of the wolf-like clade and some of the red fox-like clade. A-type faces tended to be observed in species living in family groups all year-round, whereas B-type faces tended to be seen in solo/pair-living species. The duration of gazing behavior during which the facial gaze-signal is displayed to the other individual was longest in gray wolves with typical A-type faces, of intermediate length in fennec foxes with typical B-type faces, and shortest in bush dogs with typical C-type faces. These results suggest that the facial color pattern of canid species is related to their gaze communication and that canids with A-type faces, especially gray wolves, use the gaze signal in conspecific communication.

  6. Gaze, goals and growing up: Effects on imitative grasping.

    Science.gov (United States)

    Brubacher, Sonja P; Roberts, Kim P; Obhi, Sukhvinder S

    2013-09-01

    Developmental differences in the use of social-attention cues to imitation were examined among children aged 3 and 6 years old (n = 58) and adults (n = 29). In each of 20 trials, participants watched a model grasp two objects simultaneously and move them together. On every trial, the model directed her gaze towards only one of the objects. Some object pairs were related and had a clear functional relationship (e.g., flower, vase), while others were functionally unrelated (e.g., cardboard square, ladybug). Owing to attentional effects of eye gaze, it was expected that all participants would more faithfully imitate the grasp on the gazed-at object than the object not gazed-at. Children were expected to imitate less faithfully on trials with functionally related objects than those without, due to goal-hierarchy effects. Results support effects of eye gaze on imitation of grasping. Children's grasping accuracy on functionally related and functionally unrelated trials was similar, but they were more likely to only use one hand on trials where the object pairs were functionally related than unrelated. Implications for theories of imitation are discussed. © 2013 The British Psychological Society.

  7. Investigating gaze of children with ASD in naturalistic settings.

    Directory of Open Access Journals (Sweden)

    Basilio Noris

    Full Text Available BACKGROUND: Visual behavior is known to be atypical in Autism Spectrum Disorders (ASD. Monitor-based eye-tracking studies have measured several of these atypicalities in individuals with Autism. While atypical behaviors are known to be accentuated during natural interactions, few studies have been made on gaze behavior in natural interactions. In this study we focused on i whether the findings done in laboratory settings are also visible in a naturalistic interaction; ii whether new atypical elements appear when studying visual behavior across the whole field of view. METHODOLOGY/PRINCIPAL FINDINGS: Ten children with ASD and ten typically developing children participated in a dyadic interaction with an experimenter administering items from the Early Social Communication Scale (ESCS. The children wore a novel head-mounted eye-tracker, measuring gaze direction and presence of faces across the child's field of view. The analysis of gaze episodes to faces revealed that children with ASD looked significantly less and for shorter lapses of time at the experimenter. The analysis of gaze patterns across the child's field of view revealed that children with ASD looked downwards and made more extensive use of their lateral field of view when exploring the environment. CONCLUSIONS/SIGNIFICANCE: The data gathered in naturalistic settings confirm findings previously obtained only in monitor-based studies. Moreover, the study allowed to observe a generalized strategy of lateral gaze in children with ASD when they were looking at the objects in their environment.

  8. Delayed Equation for Charged Rigid Nonrelativistic Ball

    CERN Document Server

    Vlasov, A A

    2002-01-01

    Simple expression for self-force acting on radiating rigid charged ball is derived (Sommerfeld ball). It is shown that appropriate delayed equation of motion has solutions in general differ from that for Sommerfeld sphere - there are no "radiationless" solutions, but there are oscillating without damping solutions though self-force has nonzero value.

  9. Process engineering with planetary ball mills.

    Science.gov (United States)

    Burmeister, Christine Friederike; Kwade, Arno

    2013-09-21

    Planetary ball mills are well known and used for particle size reduction on laboratory and pilot scales for decades while during the last few years the application of planetary ball mills has extended to mechanochemical approaches. Processes inside planetary ball mills are complex and strongly depend on the processed material and synthesis and, thus, the optimum milling conditions have to be assessed for each individual system. The present review focuses on the insight into several parameters like properties of grinding balls, the filling ratio or revolution speed. It gives examples of the aspects of grinding and illustrates some general guidelines to follow for modelling processes in planetary ball mills in terms of refinement, synthesis' yield and contamination from wear. The amount of energy transferred from the milling tools to the powder is significant and hardly measurable for processes in planetary ball mills. Thus numerical simulations based on a discrete-element-method are used to describe the energy transfer to give an adequate description of the process by correlation with experiments. The simulations illustrate the effect of the geometry of planetary ball mills on the energy entry. In addition the imaging of motion patterns inside a planetary ball mill from simulations and video recordings is shown.

  10. NCI and Leidos Play Ball | Poster

    Science.gov (United States)

    By Carolynne Keenan, Contributing Writer The ping of an aluminum bat off a ball or the thump of a pop-up fly ball caught in a glove are two sounds familiar to baseball fans. Slow-pitch softball sounds—like those in the August game between mixed teams of NCI and Leidos Biomedical Research (formerly SAIC-Frederick) players—are similar.

  11. Some Mathematics and Physics of Ball Games.

    Science.gov (United States)

    Hughes, D. E.

    1985-01-01

    Gives examples on the applications of arithmetic, geometry, and some calculus, vector algebra, and mechanics to ball games. Suggestions for further interesting investigations are provided together with references to other articles and books on applications of mathematics and physics to ball games and sports in general. (JN)

  12. Soccer Ball Lift Coefficients via Trajectory Analysis

    Science.gov (United States)

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  13. Coefficient of Restitution of a Tennis Ball

    Directory of Open Access Journals (Sweden)

    Andre Roux

    2007-06-01

    Full Text Available The coefficient of restitution (COR of a tennis ball was investigated over a range of impact velocities. It was found that the COR of the ball was lower than ATP regulations specify, and that the COR decreased with increasing impact velocity.

  14. Soccer Ball Lift Coefficients via Trajectory Analysis

    Science.gov (United States)

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  15. Effects of Gaze Direction Perception on Gaze Following Behavior%注视方向的知觉对注视追随行为的影响

    Institute of Scientific and Technical Information of China (English)

    张智君; 赵亚军; 占琪涛

    2011-01-01

    他人的注视线索可诱导观察者将注意自动地转移到该线索所指示的方向上去(注视追随),但仍不清楚注视方向的知觉在注视追随中起到何种作用.本研究结合注视适应和注视线索提示范式发现:知觉到的注视线索角度越大,其线索提示效应越强;知觉适应后被试判断注视方向的准确性下降,注视线索引起的注意转移量显著减少.可见,对注视方向的知觉能直接影响注视追随行为,而注视方向抽取受到刺激显著性(注视角度)和知觉适应等因素的调节.这提示:在意识状态下,注视知觉与注视追随存在直接联系,即可能存在从注视知觉系统到注意转移系统的皮层加工通路;注视追随并非纯粹的反射式加工,它受自上而下知觉经验的调节.%Observing another person's averted eye gaze leads to automatic shift of attention to the same object and facilitates subsequent early visual processing. This phenomenon is termed 'Joint attention'. Joint attention processing proceeds through two main stages: gaze perception and gaze following. Gaze perception refers to analysis of the perceptual features of a gaze cue. By contrast, gaze following refers to the tendency of observers to shift attention to locations looked at by others, which is indicated by gaze cueing effect (GCE). Most of researchers maintained that the latter process relied on the former (serial model). They hold an idea that mechanisms involved in gaze perception precede those involved in attentional cueing from gaze. However, other results suggested that gaze perception and gaze following might involve dissociable mechanisms (parallel model). As Doherty et al. (2009) reported in young children, it was possible for gaze following to occur in the absence of precise gaze perception. Thus, it remains unclear what role the gaze perception plays in gaze following behavior. In the current study, a gaze adaptation technique and a gaze cueing paradigm

  16. The principal time balls of New Zealand

    Science.gov (United States)

    Kinns, Roger

    2017-04-01

    Accurate time signals in New Zealand were important for navigation in the Pacific. Time balls at Wellington and Lyttelton were noted in the 1880 Admiralty list of time signals, with later addition of Otago. The time ball service at Wellington started in March 1864 using the first official observatory in New Zealand, but there was no Wellington time ball service during a long period of waterfront redevelopment during the 1880s. The time ball service restarted in November 1888 at a different harbour location. The original mechanical apparatus was used with a new ball, but the system was destroyed by fire in March 1909 and was never replaced. Instead, a time light service was inaugurated in 1912. The service at Lyttelton, near Christchurch, began in December 1876 after construction of the signal station there. It used telegraph signals from Wellington to regulate the time ball. By the end of 1909, it was the only official time ball in New Zealand, providing a service that lasted until 1934. The Lyttelton time ball tower was an iconic landmark in New Zealand that had been carefully restored. Tragically, the tower collapsed in the 2011 earthquakes and aftershocks that devastated Christchurch. A daily time ball service at Port Chalmers, near Dunedin, started in June 1867, initially using local observatory facilities. The service appears to have been discontinued in October 1877, but was re-established in April 1882 as a weekly service, with control by telegraph from Wellington. The service had been withdrawn altogether by the end of 1909. Auckland never established a reliable time ball service, despite provision of a weekly service for mariners by a public-spirited citizen between August 1864 and June 1866. A time ball was finally installed on the Harbour Board building in 1901, but the signal was unreliable and it ceased in 1902. Complaints from ships' masters led to various proposals to re-establish a service. These concluded with erection of a time ball on the new

  17. A non-verbal turing test: Differentiating mind from machine in gaze-based social interaction

    OpenAIRE

    Ulrich J Pfeiffer; Bert Timmermans; Gary Bente; Kai Vogeley; Leonhard Schilbach

    2011-01-01

    In social interaction, gaze behavior provides important signals that have a significant impact on our perception of others. Previous investigations, however, have relied on paradigms in which participants are passive observers of other persons' gazes and do not adjust their gaze behavior as is the case in real-life social encounters. We used an interactive eye-tracking paradigm that allows participants to interact with an anthropomorphic virtual character whose gaze behavior is responsive to ...

  18. Utilizing Gaze Behavior for Inferring Task Transitions Using Abstract Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Daniel Fernando Tello Gamarra

    2016-12-01

    Full Text Available We demonstrate an improved method for utilizing observed gaze behavior and show that it is useful in inferring hand movement intent during goal directed tasks. The task dynamics and the relationship between hand and gaze behavior are learned using an Abstract Hidden Markov Model (AHMM. We show that the predicted hand movement transitions occur consistently earlier in AHMM models with gaze than those models that do not include gaze observations.

  19. Archetypal-Imaging and Mirror-Gazing

    Directory of Open Access Journals (Sweden)

    Giovanni B. Caputo

    2013-12-01

    Full Text Available Mirrors have been studied by cognitive psychology in order to understand self-recognition, self-identity, and self-consciousness. Moreover, the relevance of mirrors in spirituality, magic and arts may also suggest that mirrors can be symbols of unconscious contents. Carl G. Jung investigated mirrors in relation to the unconscious, particularly in Psychology and Alchemy. However, the relationship between the conscious behavior in front of a mirror and the unconscious meaning of mirrors has not been clarified. Recently, empirical research found that gazing at one’s own face in the mirror for a few minutes, at a low illumination level, produces the perception of bodily dysmorphic illusions of strange-faces. Healthy observers usually describe huge distortions of their own faces, monstrous beings, prototypical faces, faces of relatives and deceased, and faces of animals. In the psychiatric population, some schizophrenics show a dramatic increase of strange-face illusions. They can also describe the perception of multiple-others that fill the mirror surface surrounding their strange-face. Schizophrenics are usually convinced that strange-face illusions are truly real and identify themselves with strange-face illusions, diversely from healthy individuals who never identify with them. On the contrary, most patients with major depression do not perceive strange-face illusions, or they perceive very faint changes of their immobile faces in the mirror, like death statues. Strange-face illusions may be the psychodynamic projection of the subject’s unconscious archetypal contents into the mirror image. Therefore, strange-face illusions might provide both an ecological setting and an experimental technique for “imaging of the unconscious”. Future researches have been proposed.

  20. Archetypal-imaging and mirror-gazing.

    Science.gov (United States)

    Caputo, Giovanni B

    2014-03-01

    Mirrors have been studied by cognitive psychology in order to understand self-recognition, self-identity, and self-consciousness. Moreover, the relevance of mirrors in spirituality, magic and arts may also suggest that mirrors can be symbols of unconscious contents. Carl G. Jung investigated mirrors in relation to the unconscious, particularly in Psychology and Alchemy. However, the relationship between the conscious behavior in front of a mirror and the unconscious meaning of mirrors has not been clarified. Recently, empirical research found that gazing at one's own face in the mirror for a few minutes, at a low illumination level, produces the perception of bodily dysmorphic illusions of strange-faces. Healthy observers usually describe huge distortions of their own faces, monstrous beings, prototypical faces, faces of relatives and deceased, and faces of animals. In the psychiatric population, some schizophrenics show a dramatic increase of strange-face illusions. They can also describe the perception of multiple-others that fill the mirror surface surrounding their strange-face. Schizophrenics are usually convinced that strange-face illusions are truly real and identify themselves with strange-face illusions, diversely from healthy individuals who never identify with them. On the contrary, most patients with major depression do not perceive strange-face illusions, or they perceive very faint changes of their immobile faces in the mirror, like death statues. Strange-face illusions may be the psychodynamic projection of the subject's unconscious archetypal contents into the mirror image. Therefore, strange-face illusions might provide both an ecological setting and an experimental technique for "imaging of the unconscious". Future researches have been proposed.

  1. Ritual relieved axial dystonia triggered by gaze-evoked amaurosis.

    Science.gov (United States)

    Jacome, D E

    1997-11-01

    A woman with chronic posttraumatic axial lateropulsion cervical dystonia ("belly dancer's head") found relief of her spontaneous dystonic spasms by the sequential performance of an elaborate motor ritual. During an episode of left optic papillitis caused by central retinal vein occlusion, gaze-evoked amaurosis of the left eye developed, preceded by achromatopsia, during left lateral gaze. Gaze-evoked amaurosis triggered axial dystonia, which was followed by her unique, stereotyped, dystonia-relieving ritual that simulated a slow dance. Visual symptoms improved progressively in 1 year. Eventually, she was unable to trigger her dystonia by eye movements. Spontaneous dystonia remained otherwise unchanged from before the episode of papillitis and was still relieved by her unique ritual.

  2. Gaze strategy in the free flying zebra finch (Taeniopygia guttata.

    Directory of Open Access Journals (Sweden)

    Dennis Eckmeier

    Full Text Available Fast moving animals depend on cues derived from the optic flow on their retina. Optic flow from translational locomotion includes information about the three-dimensional composition of the environment, while optic flow experienced during a rotational self motion does not. Thus, a saccadic gaze strategy that segregates rotations from translational movements during locomotion will facilitate extraction of spatial information from the visual input. We analysed whether birds use such a strategy by highspeed video recording zebra finches from two directions during an obstacle avoidance task. Each frame of the recording was examined to derive position and orientation of the beak in three-dimensional space. The data show that in all flights the head orientation was shifted in a saccadic fashion and was kept straight between saccades. Therefore, birds use a gaze strategy that actively stabilizes their gaze during translation to simplify optic flow based navigation. This is the first evidence of birds actively optimizing optic flow during flight.

  3. Gaze strategy in the free flying zebra finch (Taeniopygia guttata).

    Science.gov (United States)

    Eckmeier, Dennis; Geurten, Bart R H; Kress, Daniel; Mertes, Marcel; Kern, Roland; Egelhaaf, Martin; Bischof, Hans-Joachim

    2008-01-01

    Fast moving animals depend on cues derived from the optic flow on their retina. Optic flow from translational locomotion includes information about the three-dimensional composition of the environment, while optic flow experienced during a rotational self motion does not. Thus, a saccadic gaze strategy that segregates rotations from translational movements during locomotion will facilitate extraction of spatial information from the visual input. We analysed whether birds use such a strategy by highspeed video recording zebra finches from two directions during an obstacle avoidance task. Each frame of the recording was examined to derive position and orientation of the beak in three-dimensional space. The data show that in all flights the head orientation was shifted in a saccadic fashion and was kept straight between saccades. Therefore, birds use a gaze strategy that actively stabilizes their gaze during translation to simplify optic flow based navigation. This is the first evidence of birds actively optimizing optic flow during flight.

  4. Towards emotion modeling based on gaze dynamics in generic interfaces

    DEFF Research Database (Denmark)

    Vester-Christensen, Martin; Leimberg, Denis; Ersbøll, Bjarne Kjær

    2005-01-01

    Gaze detection can be a useful ingredient in generic human computer interfaces if current technical barriers are overcome. We discuss the feasibility of concurrent posture and eye-tracking in the context of single (low cost) camera imagery. The ingredients in the approach are posture and eye regi...... extraction based on active appearance modeling and eye tracking using a new fast and robust heuristic. The eye tracker is shown to perform well for low resolution image segments, hence, making it feasible to estimate gaze using a single generic camera.......Gaze detection can be a useful ingredient in generic human computer interfaces if current technical barriers are overcome. We discuss the feasibility of concurrent posture and eye-tracking in the context of single (low cost) camera imagery. The ingredients in the approach are posture and eye region...

  5. Gazing-detection of human eyes based on SVM

    Institute of Scientific and Technical Information of China (English)

    LI Su-mei; ZHANG Yan-xin; CHANG Sheng-jiang; SHEN Jin-yuan

    2005-01-01

    A method for gazing-detection of human eyes using Support Vector Machine (SVM) based on statistic learning theory (SLT) is proposed.According to the criteria of structural risk minimization of SVM,the errors between sample-data and model-data are minimized and the upper bound of predicting error of the model is also reduced.As a result,the generalization ability of the model is much improved.The simulation results show that,when limited training samples are used,the correct recognition rate of the tested samples can be as high as 100%,which is much better than some previous results obtained by other methods.The higher processing speed enables the system to distinguish gazing or not-gazing in real-time.

  6. Towards emotion modeling based on gaze dynamics in generic interfaces

    DEFF Research Database (Denmark)

    Vester-Christensen, Martin; Leimberg, Denis; Ersbøll, Bjarne Kjær

    2005-01-01

    Gaze detection can be a useful ingredient in generic human computer interfaces if current technical barriers are overcome. We discuss the feasibility of concurrent posture and eye-tracking in the context of single (low cost) camera imagery. The ingredients in the approach are posture and eye regi...... extraction based on active appearance modeling and eye tracking using a new fast and robust heuristic. The eye tracker is shown to perform well for low resolution image segments, hence, making it feasible to estimate gaze using a single generic camera.......Gaze detection can be a useful ingredient in generic human computer interfaces if current technical barriers are overcome. We discuss the feasibility of concurrent posture and eye-tracking in the context of single (low cost) camera imagery. The ingredients in the approach are posture and eye region...

  7. Gaze-direction-based MEG averaging during audiovisual speech perception

    Directory of Open Access Journals (Sweden)

    Lotta Hirvenkari

    2010-03-01

    Full Text Available To take a step towards real-life-like experimental setups, we simultaneously recorded magnetoencephalographic (MEG signals and subject’s gaze direction during audiovisual speech perception. The stimuli were utterances of /apa/ dubbed onto two side-by-side female faces articulating /apa/ (congruent and /aka/ (incongruent in synchrony, repeated once every 3 s. Subjects (N = 10 were free to decide which face they viewed, and responses were averaged to two categories according to the gaze direction. The right-hemisphere 100-ms response to the onset of the second vowel (N100m’ was a fifth smaller to incongruent than congruent stimuli. The results demonstrate the feasibility of realistic viewing conditions with gaze-based averaging of MEG signals.

  8. COGAIN2009 - "Gaze interaction for those who want it most"

    DEFF Research Database (Denmark)

    , with substantial amounts of applications to support communication, learning and entertainment already in use. However, there are still some uncertainties about this new technology amongst communication specialists and funding institutions. The 5th COGAIN conference will focus on spreading the experiences of people...... using gaze interaction in their daily life to potential users and specialists who have yet to benefit from it. The theme of the conference is "Gaze interaction for those who want it most". We present a total of 18 papers that have been reviewed and accepted by leading researchers and communication...... specialists. Several papers address gaze-based access to computer applications and several papers focus on environmental control. Previous COGAIN conferences have been a most effective launch pad for original new research ideas. Some of them have since found their way into journals and other conferences...

  9. La balle et la plume

    Directory of Open Access Journals (Sweden)

    Peter Marquis

    2012-06-01

    Full Text Available Fin octobre 2008, la nouvelle fit l’effet d’une bombe : Barack Obama, alors candidat à la présidence américaine, demanda à la chaîne câblée Fox News de retarder le début du sixième match de la World Series de base-ball afin de diffuser un spot de campagne. Son adversaire, John McCain, soutenu par le camp républicain et une partie de la population, monta aussitôt au créneau pour dénoncer l’hérésie : s’arroger le droit de perturber cette grande finale du championnat au déroulement immuable reve...

  10. Interacting with Objects in the Environment by Gaze and Hand Gestures

    DEFF Research Database (Denmark)

    Hales, Jeremy; Mardanbeigi, Diako; Rozado, David

    2013-01-01

    A head-mounted wireless gaze tracker in the form of gaze tracking glasses is used here for continuous and mobile monitoring of a subject's point of regard on the surrounding environment. We combine gaze tracking and hand gesture recognition to allow a subject to interact with objects...

  11. Revisiting the Relationship between the Processing of Gaze Direction and the Processing of Facial Expression

    Science.gov (United States)

    Ganel, Tzvi

    2011-01-01

    There is mixed evidence on the nature of the relationship between the perception of gaze direction and the perception of facial expressions. Major support for shared processing of gaze and expression comes from behavioral studies that showed that observers cannot process expression or gaze and ignore irrelevant variations in the other dimension.…

  12. Toddlers' gaze following through attention modulation : Intention is in the eye of the beholder

    NARCIS (Netherlands)

    de Bordes, Pieter F.; Cox, Ralf F. A.; Hasselman, Fred; Cillessen, Antonius H. N.

    2013-01-01

    We investigated 20-month-olds' (N = 56) gaze following by presenting toddlers with a female model that displayed either ostensive or no ostensive cues before shifting her gaze laterally toward an object. The results indicated that toddlers reliably followed the model's gaze redirection after mutual

  13. "Gaze Leading": Initiating Simulated Joint Attention Influences Eye Movements and Choice Behavior

    Science.gov (United States)

    Bayliss, Andrew P.; Murphy, Emily; Naughtin, Claire K.; Kritikos, Ada; Schilbach, Leonhard; Becker, Stefanie I.

    2013-01-01

    Recent research in adults has made great use of the gaze cuing paradigm to understand the behavior of the follower in joint attention episodes. We implemented a gaze leading task to investigate the initiator--the other person in these triadic interactions. In a series of gaze-contingent eye-tracking studies, we show that fixation dwell time upon…

  14. Early averted gaze processing in the right Fusiform Gyrus: An EEG source imaging study.

    Science.gov (United States)

    Berchio, Cristina; Rihs, Tonia A; Piguet, Camille; Dayer, Alexandre G; Aubry, Jean-Michel; Michel, Christoph M

    2016-09-01

    Humans are able to categorize face properties with impressively short latencies. Nevertheless, the latency at which gaze recognition occurs is still a matter of debate. Through spatio-temporal analysis of high-density event-related potentials (ERP), we investigated the brain activity underlying the ability to spontaneously and quickly process gaze. We presented neutral faces with direct and averted gaze in a matching picture paradigm, where subjects had to detect repetition of identical faces and gaze was implicitly manipulated. The results indicate that faces with averted gaze were better discriminated than faces with direct gaze, and evoked stronger P100 amplitudes localized to the right fusiform gyrus. In contrast, direct gaze induced stronger activation in the orbital frontal gyrus at this latency. Later in time, at the beginning of the N170 component, direct gaze induced changes in scalp topography with a stronger activation in the right medial temporal gyrus. The location of these differential activations of direct vs. averted gaze further support the view that faces with averted gaze are perceived as less rewarding than faces with direct gaze. We additionally found differential ERP responses between repeated and novel faces as early as 50ms, thereby replicating earlier studies of very fast detection of mnestic aspects of stimuli. Together, these results suggest an early dissociation between implicit gaze detection and explicit identity processing.

  15. Early development of gaze following into distant space in juvenile Greylag geese (Anser anser)

    NARCIS (Netherlands)

    Kehmeier, Sophia; Schloegl, Christian; Scheiber, Isabella B. R.; Weiss, Brigitte M.

    2011-01-01

    Visual co-orientation with another's gaze direction (gaze following) may provide important information about the location of food, social interactions or predators. Gaze following has been shown in a variety of mammals, but only in few bird species, and has not been tested in precocial birds at all.

  16. Effect of soya milk on nutritive, antioxidative, reological and textural properties of chocolate produced in a ball mill

    OpenAIRE

    Zarić Danica B.; Pajin Biljana S.; Rakin Marica B.; Šereš Zita I.; Dokić Ljubica P.; Tomić Jelena M.

    2011-01-01

    Chocolate is a complex rheological system in which non-fat cocoa particles and sugar particles are enveloped by crystal matrix of cocoa butter. Physical properties of chocolate depend on ingredient composition, method of production and properly performed pre-crystallization phase. In this work, chocolate was produced in an unconventional way, i.e. in a ball mill applying variable refining time (30, 60 and 90 min) and pre-crystallization temperature in chocolate masses (26, 28 and 30⁰C)....

  17. Investigating social gaze as an action-perception online performance

    Directory of Open Access Journals (Sweden)

    Ouriel eGrynszpan

    2012-04-01

    Full Text Available In interpersonal interactions, linguistic information is complemented by non-linguistic information originating largely from facial expressions. The study of online face-to-face social interaction thus entails investigating the multimodal simultaneous processing of oral and visual percepts. Moreover, gaze in and of itself functions as a powerful communicative channel. In this respect, gaze should not be examined as a purely perceptive process but also as an active social performance. We designed a task involving multimodal deciphering of social information based on virtual characters, embedded in naturalistic backgrounds, who directly address the participant with non-literal speech and meaningful facial expressions. Eighteen adult participants were to interpret an equivocal sentence which could be disambiguated by examining the emotional expressions of the character speaking to them face-to-face. To examine self-control and self-awareness of gaze in this context, visual feedback is provided to the participant by a real-time gaze-contingent viewing window centered on the focal point, while the rest of the display is blurred. Eye-tracking data showed that the viewing window induced changes in gaze behaviour, notably longer visual fixations. Notwithstanding, only half the participants ascribed the window displacements to their eye movements. These results highlight the dissociation between non volitional gaze adaptation and self-ascription of agency. Such dissociation provides support for a two-step account of the sense of agency composed of pre-noetic monitoring mechanisms and reflexive processes. We comment upon these results, which illustrate the relevance of our method for studying online social cognition, especially concerning Autism Spectrum Disorders (ASD where poor pragmatic understanding of oral speech are considered linked to visual peculiarities that impede face exploration.

  18. The Rethorics of Gaze in Luhrmann's "Postmodern Great Gatsby"

    Directory of Open Access Journals (Sweden)

    Paola Fallerini

    2014-05-01

    Full Text Available Baz Luhrmann’s latest movie amplifies to exasperation Fitzgerald's novel, in a triumph of saturated images, sparkling scenes, bombastic and overwhelming music.The representation of Jay Gatsby love obsession reaches so high-sounding tones to almost touch the tones of farce.The postmodern transposition of the novel highlights the game of gazes subtended to the narrative texture of the story and especially enhances the turning points of textual composition.Adopting the perspective suggested by the rhetoric of the gaze (Laura Mulvey it is highlighted the metalinguistic and metatextual reflection through which this movie contributes to the critical interpretation of Fitzgerald’s novel.

  19. Learning to interact with a computer by gaze

    DEFF Research Database (Denmark)

    Aoki, Hirotaka; Hansen, John Paulin; Itoh, Kenji

    2008-01-01

    The aim of this paper is to examine the learning processes that subjects undertake when they start using gaze as computer input. A 7-day experiment with eight Japanese students was carried out to record novice users’ eye movement data during typing of 110 sentences. The experiment revealed...... that inefficient eye movements was dramatically reduced after only 15 to 25 sentences of typing, equal to approximately 3-4 hours of practice. The performance data fits a general learning model based on the power law of practice. The learning model can be used to estimate further improvements in gaze typing...

  20. [Unilateral Solar Maculopathy after Gazing at Solar Eclipse].

    Science.gov (United States)

    Mehlan, J; Linke, S J; Wagenfeld, L; Steinberg, J

    2016-06-01

    A 43-year-old male patient with unilateral metamorphosia presented after gazing at an eclipse with only one eye. Damage of the macula was demonstrated funduscopically, with OCT and angiography. Six weeks after initial presentation and oral methylprednisolone therapy (40 mg/d for 10 days), the symptoms and the morphological changes decreased. Solar retinopathy is a photochemical alteration of the retina, usually seen after sun gazing. In younger patients, it mostly presents as bilateral solar maculopathy. Some patients exhibit partial or total recovery.

  1. Cricket Ball Aerodynamics: Myth Versus Science

    Science.gov (United States)

    Mehta, Rabindra D.; Koga, Demmis J. (Technical Monitor)

    2000-01-01

    Aerodynamics plays a prominent role in the flight of a cricket ball released by a bowler. The main interest is in the fact that the ball can follow a curved flight path that is not always under the control of the bowler. ne basic aerodynamic principles responsible for the nonlinear flight or "swing" of a cricket ball were identified several years ago and many papers have been published on the subject. In the last 20 years or so, several experimental investigations have been conducted on cricket ball swing, which revealed the amount of attainable swing, and the parameters that affect it. A general overview of these findings is presented with emphasis on the concept of late swing and the effects of meteorological conditions on swing. In addition, the relatively new concept of "reverse" swing, how it can be achieved in practice and the role in it of ball "tampering", are discussed in detail. A discussion of the "white" cricket ball used in last year's World Cup, which supposedly possesses different swing properties compared to a conventional red ball, is also presented.

  2. BALL - biochemical algorithms library 1.3

    Directory of Open Access Journals (Sweden)

    Stöckel Daniel

    2010-10-01

    Full Text Available Abstract Background The Biochemical Algorithms Library (BALL is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements. Results Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics. Conclusions BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL. Parts of the code are distributed under the GNU Public License (GPL. BALL is available as source code and binary packages from the project web site at http://www.ball-project.org. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.

  3. Designing hollow nano gold golf balls.

    Science.gov (United States)

    Landon, Preston B; Mo, Alexander H; Zhang, Chen; Emerson, Chris D; Printz, Adam D; Gomez, Alan F; DeLaTorre, Christopher J; Colburn, David A M; Anzenberg, Paula; Eliceiri, Matthew; O'Connell, Connor; Lal, Ratnesh

    2014-07-09

    Hollow/porous nanoparticles, including nanocarriers, nanoshells, and mesoporous materials have applications in catalysis, photonics, biosensing, and delivery of theranostic agents. Using a hierarchical template synthesis scheme, we have synthesized a nanocarrier mimicking a golf ball, consisting of (i) solid silica core with a pitted gold surface and (ii) a hollow/porous gold shell without silica. The template consisted of 100 nm polystyrene beads attached to a larger silica core. Selective gold plating of the core followed by removal of the polystyrene beads produced a golf ball-like nanostructure with 100 nm pits. Dissolution of the silica core produced a hollow/porous golf ball-like nanostructure.

  4. Shock-Absorbent Ball-Screw Mechanism

    Science.gov (United States)

    Hirr, Otto A., Jr.; Meneely, R. W.

    1986-01-01

    Actuator containing two ball screws in series employs Belleville springs to reduce impact loads, thereby increasing life expectancy. New application of springs increases reliability of equipment in which ball screws commonly used. Set of three springs within lower screw of ball-screw mechanism absorbs impacts that result when parts reach their upper and lower limits of movement. Mechanism designed with Belleville springs as shock-absorbing elements because springs have good energy-to-volume ratio and easily stacked to attain any stiffness and travel.

  5. Titanium carbide coatings for aerospace ball bearings

    Science.gov (United States)

    Boving, Hans J.; Haenni, Werner; Hintermann, HANS-E.

    1988-01-01

    In conventional ball bearings, steel to steel contacts between the balls and the raceways are at the origin of microwelds which lead to material transfer, surface roughening, lubricant breakdown, and finally to a loss in the bearing performances. To minimize the microwelding tendencies of the contacting partners it is necessary to modify their surface materials; the solid to solid collisions themselves are difficult to avoid. The use of titanium carbide coated steel balls can bring spectacular improvements in the performances and lifetimes of both oil-grease lubricated and oil-grease free bearings in a series of severe applications.

  6. Release Control of Dye from Agar Ball

    OpenAIRE

    板屋, 智之; 山村, 俊貴; 唐澤, 有太朗

    2013-01-01

    Agar is a special product of Nagano prefecture. To utilize agar gel as adsorbing or releasing material of dyes or drugs, spherical agar gel “agar ball” was prepared by dropping aqueous agar solution into salad oil. And releasing behavior of a dye (rhodamine B) from agar ball was studied. The dye is released easily from agar ball, but the release can be controlled by hybiridazation of agar and galatin. In addition, it was found that agar ball could extract the dye from oil phase containing the...

  7. Horizontal stability of a bouncing ball

    Science.gov (United States)

    McBennett, Brendan G.; Harris, Daniel M.

    2016-09-01

    We present an investigation of a partially elastic ball bouncing on a vertically vibrated concave parabolic surface in two dimensions. In particular, we demonstrate that simple vertical motion, wherein the ball bounces periodically at the parabola's vertex, is unstable to horizontal perturbations when the parabolic coefficient defining the surface shape exceeds a critical value. The result is a new periodic solution where the ball bounces laterally over the vertex. As the parabola is further steepened, this new solution also becomes unstable which gives rise to other complex periodic and chaotic bouncing states, all characterized by persistent lateral motion.

  8. Rebound upbeat nystagmus after lateral gaze in episodic ataxia type 2.

    Science.gov (United States)

    Kim, Hyo-Jung; Kim, Ji-Soo; Choi, Jae-Hwan; Shin, Jin-Hong; Choi, Kwang-Dong; Zee, David S

    2014-06-01

    Rebound nystagmus is a transient nystagmus that occurs on resuming the straight-ahead position after prolonged eccentric gaze. Even though rebound nystagmus is commonly associated with gaze-evoked nystagmus (GEN), development of rebound nystagmus in a different plane of gaze has not been described. We report a patient with episodic ataxia type 2 who showed transient upbeat nystagmus on resuming the straight-ahead position after sustained lateral gaze that had induced GEN and downbeat nystagmus. The rebound upbeat nystagmus may be ascribed to a shifting null in the vertical plane as a result of an adaptation to the downbeat nystagmus that developed during lateral gaze.

  9. The Development of Joint Visual Attention: A Longitudinal Study of Gaze following during Interactions with Mothers and Strangers

    Science.gov (United States)

    Gredeback, Gustaf; Fikke, Linn; Melinder, Annika

    2010-01-01

    Two- to 8-month-old infants interacted with their mother or a stranger in a prospective longitudinal gaze following study. Gaze following, as assessed by eye tracking, emerged between 2 and 4 months and stabilized between 6 and 8 months of age. Overall, infants followed the gaze of a stranger more than they followed the gaze of their mothers,…

  10. Fabrication of nanocrystalline surface composite layer on Cu plate under ball collisions.

    Science.gov (United States)

    Romankov, S; Park, Y C; Yoon, J M

    2014-10-01

    It was demonstrated that the severe plastic deformation of a surface induced by repeated ball collisions can be effectively used for fabrication of the nanocrystalline surface composite layers. The Cu disk was fixed at the top of a vibration chamber and ball treated. Al, Zr, Ni, Co and Fe were introduced into a Cu plate as contaminants from the grinding media one after the other by 15-min ball treatment. The composite structure was formed as a result of mechanical intermixing of the components. The particle size in as-fabricated layer ranged from 2 nm to 20 nm, with average values of about 7 nm. As-fabricated layer contained non-equilibrium multicomponent solid solution based on FCC Cu crystal structure, Zr-based phase, nanosized steel debris and amorphous phase. The hardness of the as-fabricated composite was almost ten times that of the initial Cu plate.

  11. Watch out! Magnetoencephalographic evidence for early modulation of attention orienting by fearful gaze cueing.

    Directory of Open Access Journals (Sweden)

    Fanny Lachat

    Full Text Available Others' gaze and emotional facial expression are important cues for the process of attention orienting. Here, we investigated with magnetoencephalography (MEG whether the combination of averted gaze and fearful expression may elicit a selectively early effect of attention orienting on the brain responses to targets. We used the direction of gaze of centrally presented fearful and happy faces as the spatial attention orienting cue in a Posner-like paradigm where the subjects had to detect a target checkerboard presented at gazed-at (valid trials or non gazed-at (invalid trials locations of the screen. We showed that the combination of averted gaze and fearful expression resulted in a very early attention orienting effect in the form of additional parietal activity between 55 and 70 ms for the valid versus invalid targets following fearful gaze cues. No such effect was obtained for the targets following happy gaze cues. This early cue-target validity effect selective of fearful gaze cues involved the left superior parietal region and the left lateral middle occipital region. These findings provide the first evidence for an effect of attention orienting induced by fearful gaze in the time range of C1. In doing so, they demonstrate the selective impact of combined gaze and fearful expression cues in the process of attention orienting.

  12. Flexible coordination of stationary and mobile conversations with gaze: Resource allocation among multiple joint activities

    Directory of Open Access Journals (Sweden)

    Eric Mayor

    2016-10-01

    Full Text Available Gaze is instrumental in coordinating face-to-face social interactions. But little is known about gaze use when social interactions co-occur with other joint activities. We investigated the case of walking while talking. We assessed how gaze gets allocated among various targets in mobile conversations, whether allocation of gaze to other targets affects conversational coordination, and whether reduced availability of gaze for conversational coordination affects conversational performance and content. In an experimental study, pairs were videotaped in four conditions of mobility (standing still, talking while walking along a straight-line itinerary, talking while walking along a complex itinerary, or walking along a complex itinerary with no conversational task. Gaze to partners was substantially reduced in mobile conversations, but gaze was still used to coordinate conversation via displays of mutual orientation, and conversational performance and content was not different between stationary and mobile conditions. Results expand the phenomena of multitasking to joint activities.

  13. The effect of gaze direction on three-dimensional face recognition in infants.

    Science.gov (United States)

    Yamashita, Wakayo; Kanazawa, So; Yamaguchi, Masami K

    2012-09-01

    Eye gaze is an important tool for social contact. In this study, we investigated whether direct gaze facilitates the recognition of three-dimensional face images in infants. We presented artificially produced face images in rotation to 6-8 month-old infants. The eye gaze of the face images was either direct or averted. Sixty-one sequential images of each face were created by rotating the vertical axis of the face from frontal view to ± 30°. The recognition performances of the infants were then compared between faces with direct gaze and faces with averted gaze. Infants showed evidence that they were able to discriminate the novel from familiarized face by 8 months of age and only when gaze is direct. These results suggest that gaze direction may affect three-dimensional face recognition in infants.

  14. Disfluencies and gaze aversion in unreliable responses to survey questions

    NARCIS (Netherlands)

    Schober, Michael F.; Conrad, Frederick G.; Dijkstra, Wil; Ongena, Yfke P.

    2012-01-01

    When survey respondents answer survey questions, they can also produce "paradata" (Couper 2000, 2008): behavioral evidence about their response process. The study reported here demonstrates that two kinds of respondent paradata - fluency of speech and gaze direction during answers - identify answers

  15. The Relationship between Children's Gaze Reporting and Theory of Mind

    Science.gov (United States)

    D'Entremont, Barbara; Seamans, Elizabeth; Boudreau, Elyse

    2012-01-01

    Seventy-nine 3- and 4-year-old children were tested on gaze-reporting ability and Wellman and Liu's (2004) continuous measure of theory of mind (ToM). Children were better able to report where someone was looking when eye and head direction were provided as a cue compared with when only eye direction cues were provided. With the exception of…

  16. Examining the durability of incidentally learned trust from gaze cues.

    Science.gov (United States)

    Strachan, James W A; Tipper, Steven P

    2017-10-01

    In everyday interactions we find our attention follows the eye gaze of faces around us. As this cueing is so powerful and difficult to inhibit, gaze can therefore be used to facilitate or disrupt visual processing of the environment, and when we experience this we infer information about the trustworthiness of the cueing face. However, to date no studies have investigated how long these impressions last. To explore this we used a gaze-cueing paradigm where faces consistently demonstrated either valid or invalid cueing behaviours. Previous experiments show that valid faces are subsequently rated as more trustworthy than invalid faces. We replicate this effect (Experiment 1) and then include a brief interference task in Experiment 2 between gaze cueing and trustworthiness rating, which weakens but does not completely eliminate the effect. In Experiment 3, we explore whether greater familiarity with the faces improves the durability of trust learning and find that the effect is more resilient with familiar faces. Finally, in Experiment 4, we push this further and show that evidence of trust learning can be seen up to an hour after cueing has ended. Taken together, our results suggest that incidentally learned trust can be durable, especially for faces that deceive.

  17. Maori in the Kingdom of the Gaze: Subjects or Critics?

    Science.gov (United States)

    Mika, Carl; Stewart, Georgina

    2016-01-01

    For Maori, a real opportunity exists to flesh out some terms and concepts that Western thinkers have adopted and that precede disciplines but necessarily inform them. In this article, we are intent on describing one of these precursory phenomena--Foucault's Gaze--within a framework that accords with a Maori philosophical framework. Our discussion…

  18. Triadic Gaze Intervention for Young Children with Physical Disabilities

    Science.gov (United States)

    Olswang, Lesley B.; Dowden, Patricia; Feuerstein, Julie; Greenslade, Kathryn; Pinder, Gay Lloyd; Fleming, Kandace

    2014-01-01

    Purpose: This randomized controlled study investigated whether a supplemental treatment designed to teach triadic gaze (TG) as a signal of coordinated joint attention would yield a significantly greater increase in TG in the experimental versus control group. Method: Eighteen 10- to 24-month-old children with severe motor impairments were randomly…

  19. Children's Bricolage under the Gaze of Teachers in Sociodramatic Play

    Science.gov (United States)

    Tam, Po Chi

    2013-01-01

    Drawing on the theory of dialogism and the literature on children's culture and cultural resistance, this article investigates the contextual and textual features of the cultural making of a group of children in sociodramatic play in a Hong Kong kindergarten. Different from other, similar studies, this study reports that under the gaze of the…

  20. Combining head pose and eye location information for gaze estimation

    NARCIS (Netherlands)

    Valenti, R.; Sebe, N.; Gevers, T.

    2012-01-01

    Head pose and eye location for gaze estimation have been separately studied in numerous works in the literature. Previous research shows that satisfactory accuracy in head pose and eye location estimation can be achieved in constrained settings. However, in the presence of nonfrontal faces, eye

  1. What Captures Gaze in Visual Design - Insights from Cognitive Psychology

    DEFF Research Database (Denmark)

    Andersen, Emil; Maier, Anja

    2016-01-01

    Visual information is vital for user behaviour and thus of utmost importance to design. Consequently, tracking and interpreting gaze data has been the target of increasing amounts of research in design science. This research is in part facilitated by new methods, such as eye-tracking, becoming more...

  2. Quality control of geological voxel models using experts' gaze

    NARCIS (Netherlands)

    Maanen, van Peter-Paul; Busschers, Freek S.; Brouwer, Anne-Marie; Meulendijk, van der Michiel J.; Erp, van Jan B.F.

    2015-01-01

    Due to an expected increase in geological voxel model data-flow and user demands, the development of improved quality control for such models is crucial. This study explores the potential of a new type of quality control that improves the detection of errors by just using gaze behavior of 12 geologi

  3. Learning to Interact with a Computer by Gaze

    Science.gov (United States)

    Aoki, Hirotaka; Hansen, John Paulin; Itoh, Kenji

    2008-01-01

    The aim of this paper is to examine the learning processes that subjects undertake when they start using gaze as computer input. A 7-day experiment with eight Japanese students was carried out to record novice users' eye movement data during typing of 110 sentences. The experiment revealed that inefficient eye movements was dramatically reduced…

  4. Differences in gaze anticipation for locomotion with and without vision

    Directory of Open Access Journals (Sweden)

    Colas Nils Authié

    2015-06-01

    Full Text Available Previous experimental studies have shown a spontaneous anticipation of locomotor trajectory by the head and gaze direction during human locomotion. This anticipatory behavior could serve several functions: an optimal selection of visual information, for instance through landmarks and optic flow, as well as trajectory planning and motor control. This would imply that anticipation remains in darkness but with different characteristics.We asked ten participants to walk along two predefined complex trajectories (limacon and figure eight without any cue on the trajectory to follow. Two visual conditions were used: (i in light and (ii in complete darkness with eyes open. The whole body kinematics were recorded by motion capture, along with the participant's right eye movements.We showed that in darkness and in light, horizontal gaze anticipates the orientation of the head which itself anticipates the trajectory direction. However, the horizontal angular anticipation decreases by a half in darkness for both gaze and head. In both visual conditions we observed an eye nystagmus with similar properties (frequency and amplitude. The main difference comes from the fact that in light, there is a shift of the orientations of the eye nystagmus and the head in the direction of the trajectory.These results suggest that a fundamental function of gaze is to represent self motion, stabilize the perception of space during locomotion, and to simulate the future trajectory, regardless of the vision condition.

  5. Maternal oxytocin response predicts mother-to-infant gaze

    Science.gov (United States)

    The neuropeptide oxytocin is importantly implicated in the emergence and maintenance of maternal behavior that forms the basis of the mother–infant bond. However, no research has yet examined the specific association between maternal oxytocin and maternal gaze, a key modality through which the mothe...

  6. Creepy White Gaze: Rethinking the Diorama as a Pedagogical Activity

    Science.gov (United States)

    Sterzuk, Andrea; Mulholland, Valerie

    2011-01-01

    Drawing on gaze and postcolonial theory, this article provides a theoretical discussion of a problematic photograph published in a provincial teachers' newsletter. The photo consists of a White settler child and two White settler educators gathered around his heritage fair entry diorama entitled "Great Plains Indians." This article…

  7. Lithium-Induced Downbeat Nystagmus and Horizontal Gaze Palsy

    DEFF Research Database (Denmark)

    Jørgensen, Jesper Skovlund; Landschoff Lassen, Lisbeth; Wegener, Marianne

    2016-01-01

    We report a case of lithium-induced downbeat nystagmus and horizontal gaze palsy in a 62-year-old woman who was treated for a bipolar affective disorder with lithium carbonate for one month. At presentation serum lithium was within therapeutic range. No alternative causes of the ocular motility...... disturbances were found, and the patient improved significantly as lithium carbonate was discontinued....

  8. More prolonged brain activity related to gaze cueing in schizophrenia

    NARCIS (Netherlands)

    Magnee, Maurice J. C. M.; Kahn, Rene S.; Cahn, Wiepke; Kemner, Chantal

    2011-01-01

    Objective: The ability to use the gaze direction of another person to guide attention is important for social functioning, but behavioral reports on this topic among individuals with schizophrenia are inconclusive. Event Related Potentials (ERPs) can very accurately pinpoint the shifting of attentio

  9. Gaze Duration Frequency Distributions During Mother-Infant Interaction

    Science.gov (United States)

    Peery, J. Craig; Stern, Daniel N.

    1976-01-01

    Gazing behavior of 10 twin infants (five male and five female) and their mothers were recorded weekly during the babies' fourth month of life. Videotape equipment was used in the home; data were gathered as naturalistically as possible. (Author/MS)

  10. How Magnus Bends the Flying Ball--Experimenting and Modeling

    Science.gov (United States)

    Timková, V.; Ješková, Z.

    2017-01-01

    Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways,…

  11. Does soccer ball heading cause retinal bleeding?

    Science.gov (United States)

    Reed, William F; Feldman, Kenneth W; Weiss, Avery H; Tencer, Alan F

    2002-04-01

    To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage. Regional Children's Hospital, youth soccer camp. Male and female soccer players, 13 to 16 years old, who regularly head soccer balls. Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball. Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7 +/- 1.3g. Rotational accelerations were negligible. Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.

  12. DEVELOPMENT OF TECHNOLOGY FOR ANODE BALL PRODUCTION

    Directory of Open Access Journals (Sweden)

    G. V. Kozhevnikova

    2015-01-01

    Full Text Available Technology of copper anode balls manufacturing by means of cross-wedge rolling method is developed. The technology satisfies the requirements towards anode balls’ crystalline structure, form and geometrical dimensions accuracy.

  13. Hyperbolic monotonicity in the Hilbert ball

    Directory of Open Access Journals (Sweden)

    Reich Simeon

    2006-01-01

    Full Text Available We first characterize -monotone mappings on the Hilbert ball by using their resolvents and then study the asymptotic behavior of compositions and convex combinations of these resolvents.

  14. Static Load Distribution in Ball Bearings

    Science.gov (United States)

    Ricci, Mario

    2010-01-01

    A numerical procedure for computing the internal loading distribution in statically loaded, single-row, angular-contact ball bearings when subjected to a known combined radial and thrust load is presented. The combined radial and thrust load must be applied in order to avoid tilting between inner and outer rings. The numerical procedure requires the iterative solution of Z + 2 simultaneous nonlinear equations - where Z is the number of the balls - to yield an exact solution for axial and radial deflections, and contact angles. Numerical results for a 218 angular-contact ball bearing have been compared with those from the literature and show significant differences in the magnitudes of the ball loads, contact angles, and the extent of the loading zone.

  15. Bouncing Balls and Hot Rod Races.

    Science.gov (United States)

    Tibbs, Peggy; Sherrill, Donna

    This paper presents the Bouncing Ball Experiment which models quadratic and exponential functions, and the Hot Rod Races activity that explores velocity and acceleration. Activities include directions for the use of TI-82 and TI-83 calculators. (YDS)

  16. Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

    Science.gov (United States)

    Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

    2013-09-01

    We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (pdolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025).

  17. Investigation on the Surface Coating of Grinding Balls

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The surface coating of grinding balls was investigated experimentally. The results show that a coating may form on the surface of grinding balls when Cr or Al powders are subjected to ball grinding. The plastic deformation of the ball surface plays an important role during the coating formation, and the strong binding force between the powders and the balls is a necessary pre-condition. The thickness of coating increases with the plasticity of the powders and the balls. Annealing the balls with coating will result in an obvious diffusion of the elements in the bonding zone of inter-face.

  18. Q-balls with scalar charges

    CERN Document Server

    Rubakov, V

    2010-01-01

    We consider Friedberg-Lee-Sirlin Q-balls in a (3+1)-dimensional model with vanishing scalar potential of one of the fields. The Q-ball is stabilized by the gradient energy of this field and carries scalar charge, over and beyond the global charge. The latter property is inherent also in a model with the scalar potential that does not vanish in some finite field region near the origin.

  19. Aerodynamic drag of modern soccer balls

    OpenAIRE

    Asai, Takeshi; SEO, KAZUYA

    2013-01-01

    Soccer balls such as the Adidas Roteiro that have been used in soccer tournaments thus far had 32 pentagonal and hexagonal panels. Recently, the Adidas Teamgeist II and Adidas Jabulani, respectively having 14 and 8 panels, have been used at tournaments; the aerodynamic characteristics of these balls have not yet been verified. Now, the Adidas Tango 12, having 32 panels, has been developed for use at tournaments; therefore, it is necessary to understand its aerodynamic characteristics. Through...

  20. A rotating ball inlet for on-line MALDI mass spectrometry.

    Science.gov (United States)

    Orsnes, H; Graf, T; Degn, H; Murray, K K

    2000-01-01

    The rotating ball inlet (ROBIN) is presented in a new design for on-line matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). This method uses a capillary to deliver a matrix and analyte solution to the surface of a rotating ball upon which MALDI is carried out. The ball is in contact with a polymer gasket surrounding the capillary. Sample adhering to the surface of the ball is dragged past the gasket into the vacuum of the mass spectrometer where it is irradiated by a pulsed UV laser, and the resulting ions are mass-separated in a linear time-of-flight mass spectrometer. The mechanical sample introduction prevents clogging of the vacuum interface by matrix crystals or frozen solvent. Preliminary results from flow injection analysis (FIA) suggest that the new interface does not introduce a significant peak-tailing or memory effect. The system is capable of 20-30 h of continuous operation with a flow rate of 2 microL/min before cleaning of the ball is needed. With the prototype inlet, concentration detection limits are at the low micromolar level.

  1. Gaze shifts during dual-tasking stair descent.

    Science.gov (United States)

    Miyasike-daSilva, Veronica; McIlroy, William E

    2016-11-01

    To investigate the role of vision in stair locomotion, young adults descended a seven-step staircase during unrestricted walking (CONTROL), and while performing a concurrent visual reaction time (RT) task displayed on a monitor. The monitor was located at either 3.5 m (HIGH) or 0.5 m (LOW) above ground level at the end of the stairway, which either restricted (HIGH) or facilitated (LOW) the view of the stairs in the lower field of view as participants walked downstairs. Downward gaze shifts (recorded with an eye tracker) and gait speed were significantly reduced in HIGH and LOW compared with CONTROL. Gaze and locomotor behaviour were not different between HIGH and LOW. However, inter-individual variability increased in HIGH, in which participants combined different response characteristics including slower walking, handrail use, downward gaze, and/or increasing RTs. The fastest RTs occurred in the midsteps (non-transition steps). While gait and visual task performance were not statistically different prior to the top and bottom transition steps, gaze behaviour and RT were more variable prior to transition steps in HIGH. This study demonstrated that, in the presence of a visual task, people do not look down as often when walking downstairs and require minimum adjustments provided that the view of the stairs is available in the lower field of view. The middle of the stairs seems to require less from executive function, whereas visual attention appears a requirement to detect the last transition via gaze shifts or peripheral vision.

  2. Can we resist another person’s gaze?

    Science.gov (United States)

    Marino, Barbara F. M.; Mirabella, Giovanni; Actis-Grosso, Rossana; Bricolo, Emanuela; Ricciardelli, Paola

    2015-01-01

    Adaptive adjustments of strategies are needed to optimize behavior in a dynamic and uncertain world. A key function in implementing flexible behavior and exerting self-control is represented by the ability to stop the execution of an action when it is no longer appropriate for the environmental requests. Importantly, stimuli in our environment are not equally relevant and some are more valuable than others. One example is the gaze of other people, which is known to convey important social information about their direction of attention and their emotional and mental states. Indeed, gaze direction has a significant impact on the execution of voluntary saccades of an observer since it is capable of inducing in the observer an automatic gaze-following behavior: a phenomenon named social or joint attention. Nevertheless, people can exert volitional inhibitory control on saccadic eye movements during their planning. Little is known about the interaction between gaze direction signals and volitional inhibition of saccades. To fill this gap, we administered a countermanding task to 15 healthy participants in which they were asked to observe the eye region of a face with the eyes shut appearing at central fixation. In one condition, participants were required to suppress a saccade, that was previously instructed by a gaze shift toward one of two peripheral targets, when the eyes were suddenly shut down (social condition, SC). In a second condition, participants were asked to inhibit a saccade, that was previously instructed by a change in color of one of the two same targets, when a change of color of a central picture occurred (non-social condition, N-SC). We found that inhibitory control was more impaired in the SC, suggesting that actions initiated and stopped by social cues conveyed by the eyes are more difficult to withhold. This is probably due to the social value intrinsically linked to these cues and the many uses we make of them. PMID:26550008

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

    Science.gov (United States)

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

    2015-07-01

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

  4. Early Left Parietal Activity Elicited by Direct Gaze: A High-Density EEG Study

    Science.gov (United States)

    Burra, Nicolas; Kerzel, Dirk; George, Nathalie

    2016-01-01

    Gaze is one of the most important cues for human communication and social interaction. In particular, gaze contact is the most primary form of social contact and it is thought to capture attention. A very early-differentiated brain response to direct versus averted gaze has been hypothesized. Here, we used high-density electroencephalography to test this hypothesis. Topographical analysis allowed us to uncover a very early topographic modulation (40–80 ms) of event-related responses to faces with direct as compared to averted gaze. This modulation was obtained only in the condition where intact broadband faces–as opposed to high-pass or low-pas filtered faces–were presented. Source estimation indicated that this early modulation involved the posterior parietal region, encompassing the left precuneus and inferior parietal lobule. This supports the idea that it reflected an early orienting response to direct versus averted gaze. Accordingly, in a follow-up behavioural experiment, we found faster response times to the direct gaze than to the averted gaze broadband faces. In addition, classical evoked potential analysis showed that the N170 peak amplitude was larger for averted gaze than for direct gaze. Taken together, these results suggest that direct gaze may be detected at a very early processing stage, involving a parallel route to the ventral occipito-temporal route of face perceptual analysis. PMID:27880776

  5. 2D Gaze Estimation Based on Pupil-Glint Vector Using an Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Jianzhong Wang

    2016-06-01

    Full Text Available Gaze estimation methods play an important role in a gaze tracking system. A novel 2D gaze estimation method based on the pupil-glint vector is proposed in this paper. First, the circular ring rays location (CRRL method and Gaussian fitting are utilized for pupil and glint detection, respectively. Then the pupil-glint vector is calculated through subtraction of pupil and glint center fitting. Second, a mapping function is established according to the corresponding relationship between pupil-glint vectors and actual gaze calibration points. In order to solve the mapping function, an improved artificial neural network (DLSR-ANN based on direct least squares regression is proposed. When the mapping function is determined, gaze estimation can be actualized through calculating gaze point coordinates. Finally, error compensation is implemented to further enhance accuracy of gaze estimation. The proposed method can achieve a corresponding accuracy of 1.29°, 0.89°, 0.52°, and 0.39° when a model with four, six, nine, or 16 calibration markers is utilized for calibration, respectively. Considering error compensation, gaze estimation accuracy can reach 0.36°. The experimental results show that gaze estimation accuracy of the proposed method in this paper is better than that of linear regression (direct least squares regression and nonlinear regression (generic artificial neural network. The proposed method contributes to enhancing the total accuracy of a gaze tracking system.

  6. Proximity and Gaze Influences Facial Temperature: A Thermal Infrared Imaging Study.

    Directory of Open Access Journals (Sweden)

    Stephanos eIoannou

    2014-08-01

    Full Text Available Direct gaze and interpersonal proximity are known to lead to changes in psycho-physiology, behaviour and brain function. We know little, however, about subtler facial reactions such as rise and fall in temperature, which may be sensitive to contextual effects and functional in social interactions. Using thermal infrared imaging cameras 18 female adult participants were filmed at two interpersonal distances (intimate and social and two gaze conditions (averted and direct. The order of variation in distance was counterbalanced: half the participants experienced a female experimenter’s gaze at the social distance first before the intimate distance (a socially ‘normal’ order and half experienced the intimate distance first and then the social distance (an odd social order. At both distances averted gaze always preceded direct gaze. We found strong correlations in thermal changes between six areas of the face (forehead, chin, cheeks, nose, maxilliary and periorbital regions for all experimental conditions and developed a composite measure of thermal shifts for all analyses. Interpersonal proximity led to a thermal rise, but only in the ‘normal’ social order. Direct gaze, compared to averted gaze, led to a thermal increase at both distances with a stronger effect at intimate distance, in both orders of distance variation. Participants reported direct gaze as more intrusive than averted gaze, especially at the intimate distance. These results demonstrate the powerful effects of another person’s gaze on psycho-physiological responses, even at a distance and independent of context.

  7. Empirical Study on Designing of Gaze Tracking Camera Based on the Information of User's Head Movement.

    Science.gov (United States)

    Pan, Weiyuan; Jung, Dongwook; Yoon, Hyo Sik; Lee, Dong Eun; Naqvi, Rizwan Ali; Lee, Kwan Woo; Park, Kang Ryoung

    2016-08-31

    Gaze tracking is the technology that identifies a region in space that a user is looking at. Most previous non-wearable gaze tracking systems use a near-infrared (NIR) light camera with an NIR illuminator. Based on the kind of camera lens used, the viewing angle and depth-of-field (DOF) of a gaze tracking camera can be different, which affects the performance of the gaze tracking system. Nevertheless, to our best knowledge, most previous researches implemented gaze tracking cameras without ground truth information for determining the optimal viewing angle and DOF of the camera lens. Eye-tracker manufacturers might also use ground truth information, but they do not provide this in public. Therefore, researchers and developers of gaze tracking systems cannot refer to such information for implementing gaze tracking system. We address this problem providing an empirical study in which we design an optimal gaze tracking camera based on experimental measurements of the amount and velocity of user's head movements. Based on our results and analyses, researchers and developers might be able to more easily implement an optimal gaze tracking system. Experimental results show that our gaze tracking system shows high performance in terms of accuracy, user convenience and interest.

  8. Effect of a ball skill intervention on children's ball skills and cognitive functions

    NARCIS (Netherlands)

    Westendorp-Haverdings, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

    Purpose: This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning

  9. Keeping Your Eyes Continuously on the Ball While Running for Catchable and Uncatchable Fly Balls

    NARCIS (Netherlands)

    Postma, Dees B. W.; den Otter, A. Rob; Zaal, Frank T. J. M.

    2014-01-01

    When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its

  10. Keeping Your Eyes Continuously on the Ball While Running for Catchable and Uncatchable Fly Balls

    NARCIS (Netherlands)

    Postma, Dees B. W.; den Otter, A. Rob; Zaal, Frank T. J. M.

    2014-01-01

    When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its init

  11. A comparative study of two types of ball-on-ball collision

    Science.gov (United States)

    White, Colin

    2017-07-01

    This paper describes three methods of measuring the coefficient of restitution (CoR) for two different types of ball-on-ball collision. The first collision type (for which two different CoR measurement procedures are described) is a static, hanging steel ball forming part of a Newton’s cradle arrangement, which is then hit by its adjacent identical ball, swinging down from an angle. The second scenario (for which one CoR measurement procedure is described) is a snooker ball interaction in which the cue ball rolls in, and collides with, a static coloured ball (both balls being of a resin composition). The investigation requires only readily available and inexpensive equipment, together with an open-source video analysis programme, called ‘Tracker’2. Perhaps surprisingly, the experiment yields widely differing CoR values for the two types of interaction. This variance cannot be solely accounted for by the difference in physical properties of the respective balls’ compositions. The paper then describes, in theoretical terms, the details of the dynamic interactions in each example, and hence validates the surprising discrepancy in the two results obtained empirically.

  12. Effect of a ball skill intervention on children's ball skills and cognitive functions

    NARCIS (Netherlands)

    Westendorp-Haverdings, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

    2014-01-01

    Purpose: This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning

  13. Gaze Behaviors of Preterm and Full-Term Infants in Nonsocial and Social Contexts of Increasing Dynamics: Visual Recognition, Attention Regulation, and Gaze Synchrony

    Science.gov (United States)

    Harel, Hagar; Gordon, Ilanit; Geva, Ronny; Feldman, Ruth

    2011-01-01

    Although research has demonstrated poor visual skills in premature infants, few studies assessed infants' gaze behaviors across several domains of functioning in a single study. Thirty premature and 30 full-term 3-month-old infants were tested in three social and nonsocial tasks of increasing complexity and their gaze behavior was micro-coded. In…

  14. Gaze Behaviors of Preterm and Full-Term Infants in Nonsocial and Social Contexts of Increasing Dynamics: Visual Recognition, Attention Regulation, and Gaze Synchrony

    Science.gov (United States)

    Harel, Hagar; Gordon, Ilanit; Geva, Ronny; Feldman, Ruth

    2011-01-01

    Although research has demonstrated poor visual skills in premature infants, few studies assessed infants' gaze behaviors across several domains of functioning in a single study. Thirty premature and 30 full-term 3-month-old infants were tested in three social and nonsocial tasks of increasing complexity and their gaze behavior was micro-coded. In…

  15. Physician supply forecast: better than peering in a crystal ball?

    Directory of Open Access Journals (Sweden)

    Leonard Christian

    2009-02-01

    Full Text Available Abstract Background Anticipating physician supply to tackle future health challenges is a crucial but complex task for policy planners. A number of forecasting tools are available, but the methods, advantages and shortcomings of such tools are not straightforward and not always well appraised. Therefore this paper had two objectives: to present a typology of existing forecasting approaches and to analyse the methodology-related issues. Methods A literature review was carried out in electronic databases Medline-Ovid, Embase and ERIC. Concrete examples of planning experiences in various countries were analysed. Results Four main forecasting approaches were identified. The supply projection approach defines the necessary inflow to maintain or to reach in the future an arbitrary predefined level of service offer. The demand-based approach estimates the quantity of health care services used by the population in the future to project physician requirements. The needs-based approach involves defining and predicting health care deficits so that they can be addressed by an adequate workforce. Benchmarking health systems with similar populations and health profiles is the last approach. These different methods can be combined to perform a gap analysis. The methodological challenges of such projections are numerous: most often static models are used and their uncertainty is not assessed; valid and comprehensive data to feed into the models are often lacking; and a rapidly evolving environment affects the likelihood of projection scenarios. As a result, the internal and external validity of the projections included in our review appeared limited. Conclusion There is no single accepted approach to forecasting physician requirements. The value of projections lies in their utility in identifying the current and emerging trends to which policy-makers need to respond. A genuine gap analysis, an effective monitoring of key parameters and comprehensive workforce planning are key elements to improving the usefulness of physician supply projections.

  16. Crystal balls, virtual realities and 'storylines'

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, R.S.

    2001-07-01

    ''Projections'' of anthropogenic climate change reported in the Third Assessment Report (TAR) of the UN Intergovernmental Panel on Climate Change (IPCC) are assessed to be based on pseudo-science. (author)

  17. Coding Without Your Crystal Ball: Unanticipated Object-Oriented Reuse

    Science.gov (United States)

    2009-12-01

    Existing solutions either restrict the formof constructor definitions [Oder- sky 2007] or ignore some constructor calls [Ellis and Stroustrup 1990...G. Plotkin, C. Stirling , and M. Tofte (Eds.), Proof, Language, and Interaction: Essays in Honor of Robin Milner. MIT Press. 115 Hutchinson, N. C

  18. Preparation of Mo-Re-C samples containing Mo7Re13C with the β-Mn-type structure by solid state reaction of planetary-ball-milled powder mixtures of Mo, Re and C, and their crystal structures and superconductivity

    Science.gov (United States)

    Oh-ishi, Katsuyoshi; Nagumo, Kenta; Tateishi, Kazuya; Takafumi, Ohnishi; Yoshikane, Kenta; Sugiyama, Machiko; Oka, Kengo; Kobayashi, Ryota

    2017-01-01

    Mo-Re-C compounds containing Mo7Re13C with the β-Mn structure were synthesized with high-melting-temperature metals Mo, Re, and C powders using a conventional solid state method with a planetary ball milling machine instead of the arc melting method. Use of the ball milling machine was necessary to obtain Mo7Re13C with the β-Mn structure using the solid state method. Almost single-phase Mo7Re13C with a trace of impurity were obtained using the synthesis method. By XRF and lattice parameter measurements on the samples, Fe element existed in the compound synthesized using the planetary ball milling machine with a pot and balls made of steel, though Fe element was not detected in the compound synthesized using a pot and balls made of tungsten carbide. The former compound containg the Fe atom did not show superconductivity but the latter compound without the Fe atom showed superconductivity at 6.1 K.

  19. Ball machine usage in tennis: movement initiation and swing timing while returning balls from a ball machine and from a real server.

    Science.gov (United States)

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-05-01

    Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers' movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key pointsPlayers have shorter initial move time when they are facing the ball machine.Using the ball machine results in different swing timing and movement coordination.The use of the ball machine should be limited.

  20. Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

    Science.gov (United States)

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-01-01

    Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers’ movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key points Players have shorter initial move time when they are facing the ball machine. Using the ball machine results in different swing timing and movement coordination. The use of the ball machine should be limited. PMID:24790483

  1. The Eyes Are the Windows to the Mind: Direct Eye Gaze Triggers the Ascription of Others' Minds.

    Science.gov (United States)

    Khalid, Saara; Deska, Jason C; Hugenberg, Kurt

    2016-12-01

    Eye gaze is a potent source of social information with direct eye gaze signaling the desire to approach and averted eye gaze signaling avoidance. In the current work, we proposed that eye gaze signals whether or not to impute minds into others. Across four studies, we manipulated targets' eye gaze (i.e., direct vs. averted eye gaze) and measured explicit mind ascriptions (Study 1a, Study 1b, and Study 2) and beliefs about the likelihood of targets having mind (Study 3). In all four studies, we find novel evidence that the ascription of sophisticated humanlike minds to others is signaled by the display of direct eye gaze relative to averted eye gaze. Moreover, we provide evidence suggesting that this differential mentalization is due, at least in part, to beliefs that direct gaze targets are more likely to instigate social interaction. In short, eye contact triggers mind perception.

  2. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  3. Wolves (Canis lupus) and Dogs (Canis familiaris) Differ in Following Human Gaze Into Distant Space But Respond Similar to Their Packmates’ Gaze

    Science.gov (United States)

    Werhahn, Geraldine; Virányi, Zsófia; Barrera, Gabriela; Sommese, Andrea; Range, Friederike

    2017-01-01

    Gaze following into distant space is defined as visual co-orientation with another individual’s head direction allowing the gaze follower to gain information on its environment. Human and nonhuman animals share this basic gaze following behavior, suggested to rely on a simple reflexive mechanism and believed to be an important prerequisite for complex forms of social cognition. Pet dogs differ from other species in that they follow only communicative human gaze clearly addressed to them. However, in an earlier experiment we showed that wolves follow human gaze into distant space. Here we set out to investigate whether domestication has affected gaze following in dogs by comparing pack-living dogs and wolves raised and kept under the same conditions. In Study 1 we found that in contrast to the wolves, these dogs did not follow minimally communicative human gaze into distant space in the same test paradigm. In the observational Study 2 we found that pack-living dogs and wolves, similarly vigilant to environmental stimuli, follow the spontaneous gaze of their conspecifics similarly often. Our findings suggest that domestication did not affect the gaze following ability of dogs itself. The results raise hypotheses about which other dog skills might have been altered through domestication that may have influenced their performance in Study 1. Because following human gaze in dogs might be influenced by special evolutionary as well as developmental adaptations to interactions with humans, we suggest that comparing dogs to other animal species might be more informative when done in intraspecific social contexts. PMID:27244538

  4. Enhancing sensorimotor activity by controlling virtual objects with gaze.

    Directory of Open Access Journals (Sweden)

    Cristián Modroño

    Full Text Available This fMRI work studies brain activity of healthy volunteers who manipulated a virtual object in the context of a digital game by applying two different control methods: using their right hand or using their gaze. The results show extended activations in sensorimotor areas, not only when participants played in the traditional way (using their hand but also when they used their gaze to control the virtual object. Furthermore, with the exception of the primary motor cortex, regional motor activity was similar regardless of what the effector was: the arm or the eye. These results have a potential application in the field of the neurorehabilitation as a new approach to generate activation of the sensorimotor system to support the recovery of the motor functions.

  5. Disseminated histoplasmosis causing reversible gaze palsy and optic neuropathy.

    Science.gov (United States)

    Perry, J D; Girkin, C A; Miller, N R; Mann, R B

    1999-06-01

    Subacute disseminated histoplasmosis is an uncommon entity. Typical neuro-ophthalmologic manifestations are usually secondary to histoplasmomas or encephalitis. A 45-year-old man noted blurred vision while receiving empiric antituberculosis therapy for fever and diffuse granulomatous disease of unknown origin. Vertical-gaze palsy, right horizontal-gaze paresis, and mild right optic neuropathy were found on neuro-ophthalmologic examination. Further questioning revealed a history of frequent contact with fighting cocks from South America. Magnetic resonance images were consistent with multiple hemorrhagic infarcts, areas of inflammation, or both, and cerebral angiography showed changes consistent with vasculitis. A previously obtained biopsy specimen from the duodenum was restained and found to be positive for fungal elements. Serum antigen titers for Histoplasma capsulatum demonstrated evidence of active infection. This case is a rare example of a supranuclear ocular motility disturbance and optic neuropathy secondary to an occlusive vascular process in a patient with subacute disseminated histoplasmosis.

  6. Influence of Gaze Direction on Face Recognition: A Sensitive Effect

    Directory of Open Access Journals (Sweden)

    Noémy Daury

    2011-08-01

    Full Text Available This study was aimed at determining the conditions in which eye-contact may improve recognition memory for faces. Different stimuli and procedures were tested in four experiments. The effect of gaze direction on memory was found when a simple “yes-no” recognition task was used but not when the recognition task was more complex (e.g., including “Remember-Know” judgements, cf. Experiment 2, or confidence ratings, cf. Experiment 4. Moreover, even when a “yes-no” recognition paradigm was used, the effect occurred with one series of stimuli (cf. Experiment 1 but not with another one (cf. Experiment 3. The difficulty to produce the positive effect of gaze direction on memory is discussed.

  7. Are you looking my way? Ostracism widens the cone of gaze.

    Science.gov (United States)

    Lyyra, Pessi; Wirth, James H; Hietanen, Jari K

    2017-08-01

    Ostracized individuals demonstrate an increased need for belonging. To satisfy this need, they search for signals of inclusion, one of which may be another person's gaze directed at oneself. We tested if ostracized, compared to included, individuals judge a greater degree of averted gaze as still being direct. This range of gaze angles still viewed as direct has been dubbed "the cone of (direct) gaze". In the current research, ostracized and included participants viewed friendly-looking face stimuli with direct or slightly averted gaze (0°, 2°, 4°, 6°, and 8° to the left and to the right) and judged whether stimulus persons were looking at them or not. Ostracized individuals demonstrated a wider gaze cone than included individuals.

  8. Camera Mouse Including “Ctrl-Alt-Del” Key Operation Using Gaze, Blink, and Mouth Shape

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-04-01

    Full Text Available This paper presents camera mouse system with additional feature: "CTRL - ALT - DEL" key. The previous gaze-based camera mouse systems are only considering how to obtain gaze and making selection. We proposed gaze-based camera mouse with "CTRL - ALT - DEL" key. Infrared camera is put on top of display while user looking ahead. User gaze is estimated based on eye gaze and head pose. Blinking and mouth detections are used to create "CTR - ALT - DEL" key. Pupil knowledge is used to improve robustness of eye gaze estimation against different users. Also, Gabor filter is used to extract face features. Skin color information and face features are used to estimate head pose. The experiments of each method have done and the results show that all methods work perfectly. By implemented this system, troubleshooting of camera mouse can be done by user itself and makes camera mouse be more sophisticated.

  9. Do as eye say: gaze cueing and language in a real-world social interaction.

    Science.gov (United States)

    Macdonald, Ross G; Tatler, Benjamin W

    2013-03-11

    Gaze cues are important in communication. In social interactions gaze cues usually occur with spoken language, yet most previous research has used artificial paradigms without dialogue. The present study investigates the interaction between gaze and language using a real-world paradigm. Each participant followed instructions to build a series of abstract structures out of building blocks, while their eye movements were recorded. The instructor varied the specificity of the instructions (unambiguous or ambiguous) and the presence of gaze cues (present or absent) between participants. Fixations to the blocks were recorded and task performance was measured. The presence of gaze cues led to more accurate performance, more accurate visual selection of the target block and more fixations towards the instructor when ambiguous instructions were given, but not when unambiguous instructions were given. We conclude that people only utilize the gaze cues of others when the cues provide useful information.

  10. Algorithm on robot soccer pass and shoot a ball

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Introduces of robot soccer's competition software of Harbin Institute of Technology(HIT), the con cept of running range and the method of calculating the running range for both the opponent and our teammates according to the distances Between the ball and robot soccers, and therefore the method of calculating the angle that the robot passes or shoots the ball according to the running ranges of both sides. And gives the examples of passing the ball when the ball's position is in the backcourt and shooting the ball when the ball's position is in the frontcourt.

  11. What Do Eye Gaze Metrics Tell Us about Motor Imagery?

    Directory of Open Access Journals (Sweden)

    Elodie Poiroux

    Full Text Available Many of the brain structures involved in performing real movements also have increased activity during imagined movements or during motor observation, and this could be the neural substrate underlying the effects of motor imagery in motor learning or motor rehabilitation. In the absence of any objective physiological method of measurement, it is currently impossible to be sure that the patient is indeed performing the task as instructed. Eye gaze recording during a motor imagery task could be a possible way to "spy" on the activity an individual is really engaged in. The aim of the present study was to compare the pattern of eye movement metrics during motor observation, visual and kinesthetic motor imagery (VI, KI, target fixation, and mental calculation. Twenty-two healthy subjects (16 females and 6 males, were required to perform tests in five conditions using imagery in the Box and Block Test tasks following the procedure described by Liepert et al. Eye movements were analysed by a non-invasive oculometric measure (SMI RED250 system. Two parameters describing gaze pattern were calculated: the index of ocular mobility (saccade duration over saccade + fixation duration and the number of midline crossings (i.e. the number of times the subjects gaze crossed the midline of the screen when performing the different tasks. Both parameters were significantly different between visual imagery and kinesthesic imagery, visual imagery and mental calculation, and visual imagery and target fixation. For the first time we were able to show that eye movement patterns are different during VI and KI tasks. Our results suggest gaze metric parameters could be used as an objective unobtrusive approach to assess engagement in a motor imagery task. Further studies should define how oculomotor parameters could be used as an indicator of the rehabilitation task a patient is engaged in.

  12. Does the 'P300' speller depend on eye gaze?

    Science.gov (United States)

    Brunner, P.; Joshi, S.; Briskin, S.; Wolpaw, J. R.; Bischof, H.; Schalk, G.

    2010-10-01

    Many people affected by debilitating neuromuscular disorders such as amyotrophic lateral sclerosis, brainstem stroke or spinal cord injury are impaired in their ability to, or are even unable to, communicate. A brain-computer interface (BCI) uses brain signals, rather than muscles, to re-establish communication with the outside world. One particular BCI approach is the so-called 'P300 matrix speller' that was first described by Farwell and Donchin (1988 Electroencephalogr. Clin. Neurophysiol. 70 510-23). It has been widely assumed that this method does not depend on the ability to focus on the desired character, because it was thought that it relies primarily on the P300-evoked potential and minimally, if at all, on other EEG features such as the visual-evoked potential (VEP). This issue is highly relevant for the clinical application of this BCI method, because eye movements may be impaired or lost in the relevant user population. This study investigated the extent to which the performance in a 'P300' speller BCI depends on eye gaze. We evaluated the performance of 17 healthy subjects using a 'P300' matrix speller under two conditions. Under one condition ('letter'), the subjects focused their eye gaze on the intended letter, while under the second condition ('center'), the subjects focused their eye gaze on a fixation cross that was located in the center of the matrix. The results show that the performance of the 'P300' matrix speller in normal subjects depends in considerable measure on gaze direction. They thereby disprove a widespread assumption in BCI research, and suggest that this BCI might function more effectively for people who retain some eye-movement control. The applicability of these findings to people with severe neuromuscular disabilities (particularly in eye-movements) remains to be determined.

  13. Horizontal gaze palsy with progressive scoliosis: CT and MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Bomfim, Rodrigo C.; Tavora, Daniel G.F.; Nakayama, Mauro; Gama, Romulo L. [Sarah Network of Rehabilitation Hospitals, Department of Radiology, Ceara (Brazil)

    2009-02-15

    Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare congenital disorder characterized by absence of conjugate horizontal eye movements and progressive scoliosis developing in childhood and adolescence. We present a child with clinical and neuroimaging findings typical of HGPPS. CT and MRI of the brain demonstrated pons hypoplasia, absence of the facial colliculi, butterfly configuration of the medulla and a deep midline pontine cleft. We briefly discuss the imaging aspects of this rare entity in light of the current literature. (orig.)

  14. Relativistic-microwave theory of ball lightning

    Science.gov (United States)

    Wu, H.-C.

    2016-06-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

  15. The bouncing ball through a geometrical series

    Science.gov (United States)

    Flores, Sergio; Alfaro, Luis L.; Chavez, Juan E.; Bastarrachea, Aztlan; Hurtado, Jazmin

    2008-10-01

    The mathematical representation of the physical situation related to a bouncing ball on the floor is an important understanding difficulty for most of the students during the introductory mechanics and mathematics courses. The research group named Physics and mathematics in context from the University of Ciudad Juarez is concerned about the versatility in the change from a mathematical representation to the own physical context of any problem under a traditional instruction. In this case, the main idea is the association of the physical properties of the bouncing ball situation to the nearest mathematical model based on a geometrical series. The proposal of the cognitive development is based on a geometrical series that shows the time the ball takes to stop. In addition, we show the behavior of the ratio of the consecutive heights during the motion.

  16. Biased discrete symmetry breaking and Fermi balls

    CERN Document Server

    MacPherson, A L; Macpherson, Alick L; Campbell, Bruce A

    1994-01-01

    The spontaneous breaking of an approximate discrete symmetry is considered, with the resulting protodomains of true and false vacuum being separated by domain walls. Given a strong, symmetric Yukawa coupling of the real scalar field to a generic fermion, the domain walls accumulate a gas of fermions, which modify the domain wall dynamics. The splitting of the degeneracy of the ground states results in the false vacuum protodomain structures eventually being fragmented into tiny false vacuum bags with a Fermi gas shell (Fermi balls), that may be cosmologically stable due to the Fermi gas pressure and wall curvature forces, acting on the domain walls. As fermions inhabiting the domain walls do not undergo number density freeze out, stable Fermi balls exist only if a fermion anti-fermion asymmetry occurs. Fermi balls formed with a new Dirac fermion that possesses no standard model gauge charges provide a novel cold dark matter candidate.

  17. Relativistic-microwave theory of ball lightning.

    Science.gov (United States)

    Wu, H-C

    2016-06-22

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

  18. From Schwinger Balls to Black Holes

    CERN Document Server

    Allahbakhshi, Davood

    2016-01-01

    We have shown intriguing similarities between Schwinger balls and black holes. By considering black hole as a gravitational Schwinger ball, we have derived the Bekenstein-Hawking entropy and the first law of black hole thermodynamics as a direct result of the inverse area dependence of the gravitational force. It is also shown that the Planck length is nothing but the gravitational Schwinger length. The relation between the mass and the radius of the black hole is derived by considering the black hole as a Schwinger ball of gravitons. We show how the evolution of the entanglement entropy of the black hole, as Page introduced many years ago, can be obtained by including gravitons in the black hole's evaporation process and using a deformed EPR mechanism. Also this deformed EPR mechanism can solve the information paradox. We show how naive simultaneous usage of Page's argument and equivalence principle leads to firewall problem.

  19. Eye gaze estimation from the elliptical features of one iris

    Science.gov (United States)

    Zhang, Wen; Zhang, Tai-Ning; Chang, Sheng-Jiang

    2011-04-01

    The accuracy of eye gaze estimation using image information is affected by several factors which include image resolution, anatomical structure of the eye, and posture changes. The irregular movements of the head and eye create issues that are currently being researched to enable better use of this key technology. In this paper, we describe an effective way of estimating eye gaze from the elliptical features of one iris under the conditions of not using an auxiliary light source, a head fixing equipment, or multiple cameras. First, we provide preliminary estimation of the gaze direction, and then we obtain the vectors which describe the translation and rotation of the eyeball, by applying a central projection method on the plane which passes through the line-of-sight. This helps us avoid the complex computations involved in previous methods. We also disambiguate the solution based on experimental findings. Second, error correction is conducted on a back propagation neural network trained by a sample collection of translation and rotation vectors. Extensive experimental studies are conducted to assess the efficiency, and robustness of our method. Results reveal that our method has a better performance compared to a typical previous method.

  20. Remote Gaze Tracking System on a Large Display

    Directory of Open Access Journals (Sweden)

    Jihun Cha

    2013-10-01

    Full Text Available We propose a new remote gaze tracking system as an intelligent TV interface. Our research is novel in the following three ways: first, because a user can sit at various positions in front of a large display, the capture volume of the gaze tracking system should be greater, so the proposed system includes two cameras which can be moved simultaneously by panning and tilting mechanisms, a wide view camera (WVC for detecting eye position and an auto-focusing narrow view camera (NVC for capturing enlarged eye images. Second, in order to remove the complicated calibration between the WVC and NVC and to enhance the capture speed of the NVC, these two cameras are combined in a parallel structure. Third, the auto-focusing of the NVC is achieved on the basis of both the user’s facial width in the WVC image and a focus score calculated on the eye image of the NVC. Experimental results showed that the proposed system can be operated with a gaze tracking accuracy of ±0.737°~±0.775° and a speed of 5~10 frames/s.

  1. Gazes and Bodies in the Pornographies of Desire

    Directory of Open Access Journals (Sweden)

    Mirko Lino

    2013-05-01

    Full Text Available Il saggio propone una lettura sociale della pornografia cinematografica usando la categoria dello sguardo e le sue declinazioni di genere. Partendo dal famoso saggio di Laura Mulvey, Visual Pleasure and Narrative Cinema (1975, si sposterà il centro dell’analisi dal cinema narrativo tradizionale al cinema pornografico, considerando quest’ultimo un modello che fa contrappunto al voyeurismo dello sguardo maschile (male gaze che la Mulvey riscontrava in alcuni film di Sternberg e di Hitckcock. Per dimostrare la natura contrappuntistica del cinema pornografico si metterà a confronto la medesima messa in scena di uno sguardo che desidera in due film molto differenti tra loro, Rear Window (1954 di Hitchcock e Behind the Green Door (1972 dei fratelli Mitchell. La natura contrappuntistica del porn movie si rintraccia anche nel dialogo che instaura con il cinema mainstream riguardo ai limiti del visibile in materia sessuale. Infine, la pornografia soddisfa la rappresentazione del desiderio delle altre identità di genere, mettendo in scena tipologie di sguardo adeguate – female gaze e queer gaze –, che diventano presto strumenti per una affermazione sociale della diversità sessuali.

  2. Holistic gaze strategy to categorize facial expression of varying intensities.

    Directory of Open Access Journals (Sweden)

    Kun Guo

    Full Text Available Using faces representing exaggerated emotional expressions, recent behaviour and eye-tracking studies have suggested a dominant role of individual facial features in transmitting diagnostic cues for decoding facial expressions. Considering that in everyday life we frequently view low-intensity expressive faces in which local facial cues are more ambiguous, we probably need to combine expressive cues from more than one facial feature to reliably decode naturalistic facial affects. In this study we applied a morphing technique to systematically vary intensities of six basic facial expressions of emotion, and employed a self-paced expression categorization task to measure participants' categorization performance and associated gaze patterns. The analysis of pooled data from all expressions showed that increasing expression intensity would improve categorization accuracy, shorten reaction time and reduce number of fixations directed at faces. The proportion of fixations and viewing time directed at internal facial features (eyes, nose and mouth region, however, was not affected by varying levels of intensity. Further comparison between individual facial expressions revealed that although proportional gaze allocation at individual facial features was quantitatively modulated by the viewed expressions, the overall gaze distribution in face viewing was qualitatively similar across different facial expressions and different intensities. It seems that we adopt a holistic viewing strategy to extract expressive cues from all internal facial features in processing of naturalistic facial expressions.

  3. Compact near-to-eye display with integrated gaze tracker

    Science.gov (United States)

    Järvenpää, Toni; Aaltonen, Viljakaisa

    2008-04-01

    Near-to-Eye Display (NED) offers a big screen experience to the user anywhere, anytime. It provides a way to perceive a larger image than the physical device itself is. Commercially available NEDs tend to be quite bulky and uncomfortable to wear. However, by using very thin plastic light guides with diffractive structures on the surfaces, many of the known deficiencies can be notably reduced. These Exit Pupil Expander (EPE) light guides enable a thin, light, user friendly and high performing see-through NED, which we have demonstrated. To be able to interact with the displayed UI efficiently, we have also integrated a video-based gaze tracker into the NED. The narrow light beam of an infrared light source is divided and expanded inside the same EPEs to produce wide collimated beams out from the EPE towards the eyes. Miniature video camera images the cornea and eye gaze direction is accurately calculated by locating the pupil and the glints of the infrared beams. After a simple and robust per-user calibration, the data from the highly integrated gaze tracker reflects the user focus point in the displayed image which can be used as an input device for the NED system. Realizable applications go from eye typing to playing games, and far beyond.

  4. Microstructure and Physical Properties of Tb2TiO5 Neutron Absorber Synthesized by Ball Milling and Sintering

    Science.gov (United States)

    Huang, Jinghua; Ran, Guang; Liu, Tengjiao; Shen, Qiang; Li, Ning

    2016-10-01

    Tb2TiO5 neutron absorber was synthesized by ball milling and sintering. Microstructure character of ball-milled Tb4O7-17.605%TiO2 (mass fraction, %) powders and sintered bulks was analyzed using XRD, SEM and TEM. The microhardness, coefficient of thermal expansion and thermal conductivity of sintered bulks were measured. The experiment results showed that the nanocrystalline solid solution was obtained during ball milling. After 96 h of ball milling, TiO2 was completely solved in Tb4O7 and the crystal size of Tb4O7 was up to 37 nm. The bulk materials prepared by cold isostatic pressing were sintered at 1300 °C. Tb2TiO5 bulks with an orthorhombic structure were obtained. The microhardness of sintered bulks, as well as the thermal conductivity, increased firstly with increasing ball milling time and then decreased. The coefficient of thermal expansion decreased initially and then increased with increasing ball milling time. For the sintered bulk with powder milled for 48 h, the highest values of both microhardness and thermal conductivity were observed, whereas the lowest coefficient of thermal expansion was exhibited. In addition, with increasing testing temperature, the thermal conductivity of sintered bulks initially fell and then rebounded while an opposite trend was found in the coefficient of thermal expansion.

  5. Dust ball physics and the Schwarzschild metric

    Science.gov (United States)

    Kassner, Klaus

    2017-08-01

    A physics-first derivation of the Schwarzschild metric is given. Gravitation is described in terms of the effects of tidal forces (or of spacetime curvature) on the volume of a small ball of test particles (a dust ball), freely falling after all particles were at rest with respect to each other initially. Because this formulation avoids the use of tensors, neither advanced tensor calculus nor sophisticated differential geometry are needed in the calculation. The derivation is not lengthy and it has visual appeal, so it may be useful in teaching.

  6. Q-Balls with Scalar Charge

    Science.gov (United States)

    Levin, A.; Rubakov, V.

    We consider Friedberg-Lee-Sirlin Q-balls in a (3+1)-dimensional model with vanishing scalar potential of one of the fields. We show that, unlike in (2+1) and (1+1) dimensions, the Q-ball is stabilized by the gradient energy of this field and carries scalar charge, over and beyond the global charge. The latter property is also inherent in a model with the scalar potential that does not vanish in a finite field region near the origin.

  7. Soccer ball lift coefficients via trajectory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2010-07-15

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

  8. Fusing Eye-gaze and Speech Recognition for Tracking in an Automatic Reading Tutor

    DEFF Research Database (Denmark)

    Rasmussen, Morten Højfeldt; Tan, Zheng-Hua

    2013-01-01

    In this paper we present a novel approach for automatically tracking the reading progress using a combination of eye-gaze tracking and speech recognition. The two are fused by first generating word probabilities based on eye-gaze information and then using these probabilities to augment the langu......In this paper we present a novel approach for automatically tracking the reading progress using a combination of eye-gaze tracking and speech recognition. The two are fused by first generating word probabilities based on eye-gaze information and then using these probabilities to augment...

  9. Evaluating gaze-based interface tools to facilitate point-and-select tasks with small targets

    DEFF Research Database (Denmark)

    Skovsgaard, Henrik; Mateo, Julio C.; Hansen, John Paulin

    2011-01-01

    Gaze interaction affords hands-free control of computers. Pointing to and selecting small targets using gaze alone is difficult because of the limited accuracy of gaze pointing. This is the first experimental comparison of gaze-based interface tools for small-target (e.g. ... when using zoom, but total pointing times were shorter using zoom. Furthermore, participants perceived magnification as more fatiguing than zoom. The higher accuracy of magnification makes it preferable when interacting with small targets. Our findings may guide the development of interface tools...

  10. Simple gaze-contingent cues guide eye movements in a realistic driving simulator

    Science.gov (United States)

    Pomarjanschi, Laura; Dorr, Michael; Bex, Peter J.; Barth, Erhardt

    2013-03-01

    Looking at the right place at the right time is a critical component of driving skill. Therefore, gaze guidance has the potential to become a valuable driving assistance system. In previous work, we have already shown that complex gaze-contingent stimuli can guide attention and reduce the number of accidents in a simple driving simulator. We here set out to investigate whether cues that are simple enough to be implemented in a real car can also capture gaze during a more realistic driving task in a high-fidelity driving simulator. We used a state-of-the-art, wide-field-of-view driving simulator with an integrated eye tracker. Gaze-contingent warnings were implemented using two arrays of light-emitting diodes horizontally fitted below and above the simulated windshield. Thirteen volunteering subjects drove along predetermined routes in a simulated environment popu­ lated with autonomous traffic. Warnings were triggered during the approach to half of the intersections, cueing either towards the right or to the left. The remaining intersections were not cued, and served as controls. The analysis of the recorded gaze data revealed that the gaze-contingent cues did indeed have a gaze guiding effect, triggering a significant shift in gaze position towards the highlighted direction. This gaze shift was not accompanied by changes in driving behaviour, suggesting that the cues do not interfere with the driving task itself.

  11. Rhesus monkeys show human-like changes in gaze following across the lifespan.

    Science.gov (United States)

    Rosati, Alexandra G; Arre, Alyssa M; Platt, Michael L; Santos, Laurie R

    2016-05-11

    Gaze following, or co-orienting with others, is a foundational skill for human social behaviour. The emergence of this capacity scaffolds critical human-specific abilities such as theory of mind and language. Non-human primates also follow others' gaze, but less is known about how the cognitive mechanisms supporting this behaviour develop over the lifespan. Here we experimentally tested gaze following in 481 semi-free-ranging rhesus macaques (Macaca mulatta) ranging from infancy to old age. We found that monkeys began to follow gaze in infancy and this response peaked in the juvenile period-suggesting that younger monkeys were especially attuned to gaze information, like humans. After sexual maturity, monkeys exhibited human-like sex differences in gaze following, with adult females showing more gaze following than males. Finally, older monkeys showed reduced propensity to follow gaze, just as older humans do. In a second study (n = 80), we confirmed that macaques exhibit similar baseline rates of looking upwards in a control condition, regardless of age. Our findings indicate that-despite important differences in human and non-human primate life-history characteristics and typical social experiences-monkeys undergo robust ontogenetic shifts in gaze following across early development, adulthood and ageing that are strikingly similar to those of humans.

  12. The role of emotion in learning trustworthiness from eye-gaze: Evidence from facial electromyography.

    Science.gov (United States)

    Manssuer, Luis R; Pawling, Ralph; Hayes, Amy E; Tipper, Steven P

    2016-01-01

    Gaze direction can be used to rapidly and reflexively lead or mislead others' attention as to the location of important stimuli. When perception of gaze direction is congruent with the location of a target, responses are faster compared to when incongruent. Faces that consistently gaze congruently are also judged more trustworthy than faces that consistently gaze incongruently. However, it's unclear how gaze-cues elicit changes in trust. We measured facial electromyography (EMG) during an identity-contingent gaze-cueing task to examine whether embodied emotional reactions to gaze-cues mediate trust learning. Gaze-cueing effects were found to be equivalent regardless of whether participants showed learning of trust in the expected direction or did not. In contrast, we found distinctly different patterns of EMG activity in these two populations. In a further experiment we showed the learning effects were specific to viewing faces, as no changes in liking were detected when viewing arrows that evoked similar attentional orienting responses. These findings implicate embodied emotion in learning trust from identity-contingent gaze-cueing, possibly due to the social value of shared attention or deception rather than domain-general attentional orienting.

  13. Gaze as a Supplementary Modality for Interacting with Ambient Intelligence Environments

    CERN Document Server

    Gepner, Daniel; Carbonell, Noëlle

    2007-01-01

    We present our current research on the implementation of gaze as an efficient and usable pointing modality supplementary to speech, for interacting with augmented objects in our daily environment or large displays, especially immersive virtual reality environments, such as reality centres and caves. We are also addressing issues relating to the use of gaze as the main interaction input modality. We have designed and developed two operational user interfaces: one for providing motor-disabled users with easy gaze-based access to map applications and graphical software; the other for iteratively testing and improving the usability of gaze-contingent displays.

  14. The effect of gaze direction on three-dimensional face recognition in infant brain activity.

    Science.gov (United States)

    Yamashita, Wakayo; Kanazawa, So; Yamaguchi, Masami K; Kakigi, Ryusuke

    2012-09-12

    In three-dimensional face recognition studies, it is well known that viewing rotating faces enhance face recognition. For infants, our previous study indicated that 8-month-old infants showed recognition of three-dimensional rotating faces with a direct gaze, and they did not learn with an averted gaze. This suggests that gaze direction may affect three-dimensional face recognition in infants. In this experiment, we used near-infrared spectroscopy to measure infants' hemodynamic responses to averted gaze and direct gaze. We hypothesized that infants would show different neural activity for averted and direct gazes. The responses were compared with the baseline activation during the presentation of non-face objects. We found that the concentration of oxyhemoglobin increased in the temporal cortex on both sides only during the presentation of averted gaze compared with that of the baseline period. This is the first study to show that infants' brain activity in three-dimensional face processing is different between averted gaze and direct gaze.

  15. Modern trends in technical crystallization

    Science.gov (United States)

    Matz, G.

    1980-04-01

    Interesting and significant developments have occurred in the last decade in both crystallization equipment and in the theory of crystallization process. In the field of technical crystallization new crystallizers have been developed and computer modelling has become important in scaling up and in the achievement of increased performance. The DP-Kristaller developed by Escher-Wyss-Tsukishima, the Brodie purifier, the sieve tray column having dancing balls, the automated multiple crystallization process due to Mützenberg and Saxer and the double belt cooler, all of which represent technical developments, are described in the first section. The second part of the paper reviews computer modelling of the fluidized bed crystallizer, chemical precipitation, flaking and prilling. Finally, there is a brief discussion of the impact of technical crystallization processes on environmental protection.

  16. Reasonable Ball Size of Ball Mill for Preparing Coal Water Fuel and Forecasting Productive Capacity

    Institute of Scientific and Technical Information of China (English)

    张荣曾; 刘炯天; 徐志强; 郑明

    2002-01-01

    By using the matrix theory, a 5-parameter grinding mathema tical model is established. Based on the properties of feed coal and requirement s for size distribution of final product, the model gives the required grinding probability for various particles and corresponding ball size distribution. By u sing this model, 3 different sizes of ball mill are designed and put into commer cial use for coal water fuel. The forecasted ball mill capacity, the particle si zes and particle size distribution as well as the coal water fuel quality parame ters are all in line with industrial operation results, which have proved the su itability of the model.

  17. Levitation of an iron ball in midair without active control

    Science.gov (United States)

    Sasaki, S.; Yagi, I.; Murakami, M.

    2004-02-01

    An iron ball floats in midair in a plastic box when several iron balls were attracted by a permanent magnet. A complex interaction between magnetized sphere materials and a lifting magnet enabled the suspension of an iron ball. The balls in the first row are simply attracted by the lifting magnet. The ball in the second row is also attracted by the lifting magnet, however, due to the repulsive forces exerted from the balls sitting above, it can float in midair. We also found that there are two stable positions for the ball to float. The floating ball could be transported from one equilibrium position to another by simply rotating the lifting magnet. This will make it possible to construct a noncontact load transport device.

  18. Soccer Ball Production for Nike in Pakistan

    NARCIS (Netherlands)

    K.A. Siegmann (Karin Astrid)

    2008-01-01

    textabstractThis paper looks at how Nike’s soccer ball suppliers (previous and current) in Sialkot (Pakistan) fare in relation to the company’s code of ethics. While minimum required working conditions are implemented, the criteria for social and environmental compliance are not met with. The

  19. Selection of Parameters in Ball-Spinning

    Institute of Scientific and Technical Information of China (English)

    Maosheng LI; Yongnian YAN; Shihong ZHANG; Dachang KANG

    2004-01-01

    Nowadays, with the development of spinning processes, more and more systematic research about spinning parameters has been published. Based on these results, a routing about how to select spinning parameters has been gradually formed. However, ball spinning, due to its own features plus research lack, is still unclear about its parameter selections. In addition, some manufacture-enterprises only notice the use of this technique whereas ignore the theory creation. The optimal parameters about the ball spinning although have been released from these enterprises but in fact not a helpful theory for other researchers and producers. Focus on selecting the parameters based on the trial-and-error, this article has carried a series of experiments to study the influence on the spinning working course from those parameters, especially the peeling phenomena, and the tube diameter bulging. An optimal graph of the working angle, the axial feeding rate, and the acceptable working course is put forward. Additionally, based on the theory of the minimal reduction rate, the selection of the ball diameter is finally described. Thus, it has given the rules to get the proper parameters in ball spinning.

  20. Soccer Ball Production for Nike in Pakistan

    NARCIS (Netherlands)

    K.A. Siegmann (Karin Astrid)

    2008-01-01

    textabstractThis paper looks at how Nike’s soccer ball suppliers (previous and current) in Sialkot (Pakistan) fare in relation to the company’s code of ethics. While minimum required working conditions are implemented, the criteria for social and environmental compliance are not met with. The multin

  1. Fractal Aggregates in Tennis Ball Systems

    Science.gov (United States)

    Sabin, J.; Bandin, M.; Prieto, G.; Sarmiento, F.

    2009-01-01

    We present a new practical exercise to explain the mechanisms of aggregation of some colloids which are otherwise not easy to understand. We have used tennis balls to simulate, in a visual way, the aggregation of colloids under reaction-limited colloid aggregation (RLCA) and diffusion-limited colloid aggregation (DLCA) regimes. We have used the…

  2. CFD analysis of a ball check microvalve

    Science.gov (United States)

    Cǎlimǎnescu, Ioan; Dumitrache, Constantin L.; Grigorescu, Lucian

    2015-02-01

    The microvalves with balls as seen before are used in many applications and their behaviour in terms of fluid dynamics mainly at their opening time (when as demonstrated the ball is bouncing up and down altering the flow parameters) is of a paramount importance. The present study is focused on a micro check ball valve circulating a fluid air-like (with the same constant proprieties). The CFD model is taking into account a transitory zone of functioning from zero time when the pressure inside a "tank" is reaching the opening pressure of the valve, to the final step 0.05 seconds when the ball is stabilizing after bouncing up and down. The geometry of the valve with dimensions in μm is given below (the model is comprising a "slice" of 5 μm thickness extracted from the entire valve. In this paper by using advanced numeric techniques, the behavior of the valve in its transitory opening stage was studied with credible and useful results for further optimisation studies.

  3. A plasma ball in the Microcosm museum

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    Plasma balls, like the one shown here, are displayed in the Microcosm exhibition where families can visit to learn more about the experiments carried out in a research institute like CERN. Hands-on activities allow visitors to get a step closer to the research activities carried out at CERN.

  4. Renal fungus ball: a challenging clinical problem.

    Science.gov (United States)

    Tan, Wei Phin; Turba, Ulku C; Deane, Leslie A

    2017-04-28

    We describe a case of renal pelvi-ureteric fungus ball managed with placement of two nephrostomy tubes and amphotericin B irrigation through a nephrostomy tube with the other to free drain. A 46-year-old man with uncontrolled Type 2 diabetes mellitus was referred to the urology clinic for workup of recurrent urinary tract infection. Urine culture grew Candida albicans. The patient was started on oral fluconazole therapy. Cystoscopy and cystogram revealed a grade 3 left vesicoureteral reflux and right retrograde pyelogram revealed a filling defect in the right renal pelvis extending into the proximal ureter with severe hydroureteronephrosis. Two nephrostomy tubes were placed (mid-pole and lower pole) to ensure that the system was not obstructed. Amphotericin B (50 mg/1000 ml normal saline) irrigation was then instilled through the mid-pole nephrostomy tube at a rate of 30 ml/h with the lower pole nephrostomy tube to free drain. An antegrade nephrostogram was performed after 5 days of amphotericin B instillation, showing complete resolution of the fungus ball. The patient is awaiting definitive minimally invasive management of the distal ureteral narrowing. Renal and pelvi-ureteric fungus ball is a challenging clinical entity. It must be addressed promptly and efficiently to be successful. We describe a minimally invasive approach that was tolerated well and resulted in complete clearance of the fungus ball in a relatively short time frame.

  5. Dark Matter Balls Help Supernovae to Explode

    CERN Document Server

    Froggatt, Colin D

    2015-01-01

    As a solution to the well-known problem that the shock wave potentially responsible for the explosion of a supernova actually tends to stall, we propose a new energy source arising from our model for dark matter. Our earlier model proposed that dark matter should consist of cm-large white dwarf-like objects kept together by a skin separating two different sorts of vacua. These dark matter balls or pearls will collect in the middle of any star throughout its lifetime. At some stage during the development of a supernova the balls will begin to take in neutrons and then other surrounding material. By passing into a ball nucleons fall through a potential of order 10 MeV, causing a severe production of heat - of order 10 foe for a solar mass of material eaten by the balls. The temperature in the iron core will thereby be raised, splitting up the iron into smaller nuclei. This provides a mechanism for reviving the shock wave when it arrives and making the supernova explosion really occur. The onset of the heating d...

  6. 4. pi. physics with the plastic ball

    Energy Technology Data Exchange (ETDEWEB)

    Gutbrod, H.H.; Loehner, H.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Warwick, A.; Weik, F.; Wieman, H.

    1982-10-01

    4 ..pi.. data taken with the Plastic Ball show that cluster production in relativistic nuclear collisions depends on both the size of the participant volume and the finite size of the cluster. The measurement of the degree of thermalization and the search for collective flow will permit the study of the applicability of macroscopic concepts such as temperature and density.

  7. Holomorphic Spaces in the Unit Ball of

    Directory of Open Access Journals (Sweden)

    Augusto Guadalupe Miss Paredes

    2013-01-01

    Full Text Available We introduce the and vector spaces of holomorphic functions defined in the unit ball of , generalizing previous work like Ouyang et al. (1998, Stroethoff (1989, and Choa et al. (1992. Likewise, we characterize those spaces in terms of harmonic majorants as a generalization of Arellano et al. (2000.

  8. Design of Ball-Milling Experiments on Bi2Te3 Thermoelectric Material

    Science.gov (United States)

    Kanatzia, A.; Papageorgiou, Ch.; Lioutas, Ch.; Kyratsi, Th.

    2013-07-01

    In this work, factorial ball-milling experiments have been applied to Bi2Te3 material, for the first time, aiming to investigate the effect of the main process parameters on the structural features and thermoelectric properties of the ball-milled materials. The selected main parameters were the duration of milling, the speed, and the ball-to-material ratio. Analysis suggests a strong effect of the speed and duration of processing, whereas the ball-to-material ratio is of minor importance. This approach is advantageous for better understanding of the milling mechanism and the importance of the role of each independent parameter as well as their interaction. All experiments led to nanocrystalline Bi2Te3, whose structural features were studied. The nanocrystalline size was estimated based on x-ray diffraction analysis, while transmission electron microscopy (TEM) studies were also performed to confirm the presence of nanoscale crystals. A mathematical model was developed based on statistical analysis for prediction of the crystalline size and the Seebeck coefficient of the nanopowders. The thermoelectric properties were also investigated on selected, highly dense pellets fabricated via hot-pressing of the nanopowders.

  9. Mirror Neurons of Ventral Premotor Cortex Are Modulated by Social Cues Provided by Others' Gaze.

    Science.gov (United States)

    Coudé, Gino; Festante, Fabrizia; Cilia, Adriana; Loiacono, Veronica; Bimbi, Marco; Fogassi, Leonardo; Ferrari, Pier Francesco

    2016-03-16

    Mirror neurons (MNs) in the inferior parietal lobule and ventral premotor cortex (PMv) can code the intentions of other individuals using contextual cues. Gaze direction is an important social cue that can be used for understanding the meaning of actions made by other individuals. Here we addressed the issue of whether PMv MNs are influenced by the gaze direction of another individual. We recorded single-unit activity in macaque PMv while the monkey was observing an experimenter performing a grasping action and orienting his gaze either toward (congruent gaze condition) or away (incongruent gaze condition) from a target object. The results showed that one-half of the recorded MNs were modulated by the gaze direction of the human agent. These gaze-modulated neurons were evenly distributed between those preferring a gaze direction congruent with the direction where the grasping action was performed and the others that preferred an incongruent gaze. Whereas the presence of congruent responses is in line with the usual coupling of hand and gaze in both executed and observed actions, the incongruent responses can be explained by the long exposure of the monkeys to this condition. Our results reveal that the representation of observed actions in PMv is influenced by contextual information not only extracted from physical cues, but also from cues endowed with biological or social value. In this study, we present the first evidence showing that social cues modulate MNs in the monkey ventral premotor cortex. These data suggest that there is an integrated representation of other's hand actions and gaze direction at the single neuron level in the ventral premotor cortex, and support the hypothesis of a functional role of MNs in decoding actions and understanding motor intentions. Copyright © 2016 the authors 0270-6474/16/363145-12$15.00/0.

  10. Gaze Synchrony between Mothers with Mood Disorders and Their Infants: Maternal Emotion Dysregulation Matters.

    Directory of Open Access Journals (Sweden)

    Annett Lotzin

    Full Text Available A lowered and heightened synchrony between the mother's and infant's nonverbal behavior predicts adverse infant development. We know that maternal depressive symptoms predict lowered and heightened mother-infant gaze synchrony, but it is unclear whether maternal emotion dysregulation is related to mother-infant gaze synchrony. This cross-sectional study examined whether maternal emotion dysregulation in mothers with mood disorders is significantly related to mother-infant gaze synchrony. We also tested whether maternal emotion dysregulation is relatively more important than maternal depressive symptoms in predicting mother-infant gaze synchrony, and whether maternal emotion dysregulation mediates the relation between maternal depressive symptoms and mother-infant gaze synchrony. We observed 68 mothers and their 4- to 9-month-old infants in the Still-Face paradigm during two play interactions, before and after social stress was induced. The mothers' and infants' gaze behaviors were coded using microanalysis with the Maternal Regulatory Scoring System and Infant Regulatory Scoring System, respectively. The degree of mother-infant gaze synchrony was computed using time-series analysis. Maternal emotion dysregulation was measured by the Difficulties in Emotion Regulation Scale; depressive symptoms were assessed using the Beck Depression Inventory. Greater maternal emotion dysregulation was significantly related to heightened mother-infant gaze synchrony. The overall effect of maternal emotion dysregulation on mother-infant gaze synchrony was relatively more important than the effect of maternal depressive symptoms in the five tested models. Maternal emotion dysregulation fully mediated the relation between maternal depressive symptoms and mother-infant gaze synchrony. Our findings suggest that the effect of the mother's depressive symptoms on the mother-infant gaze synchrony may be mediated by the mother's emotion dysregulation.

  11. Gaze Synchrony between Mothers with Mood Disorders and Their Infants: Maternal Emotion Dysregulation Matters.

    Science.gov (United States)

    Lotzin, Annett; Romer, Georg; Schiborr, Julia; Noga, Berit; Schulte-Markwort, Michael; Ramsauer, Brigitte

    2015-01-01

    A lowered and heightened synchrony between the mother's and infant's nonverbal behavior predicts adverse infant development. We know that maternal depressive symptoms predict lowered and heightened mother-infant gaze synchrony, but it is unclear whether maternal emotion dysregulation is related to mother-infant gaze synchrony. This cross-sectional study examined whether maternal emotion dysregulation in mothers with mood disorders is significantly related to mother-infant gaze synchrony. We also tested whether maternal emotion dysregulation is relatively more important than maternal depressive symptoms in predicting mother-infant gaze synchrony, and whether maternal emotion dysregulation mediates the relation between maternal depressive symptoms and mother-infant gaze synchrony. We observed 68 mothers and their 4- to 9-month-old infants in the Still-Face paradigm during two play interactions, before and after social stress was induced. The mothers' and infants' gaze behaviors were coded using microanalysis with the Maternal Regulatory Scoring System and Infant Regulatory Scoring System, respectively. The degree of mother-infant gaze synchrony was computed using time-series analysis. Maternal emotion dysregulation was measured by the Difficulties in Emotion Regulation Scale; depressive symptoms were assessed using the Beck Depression Inventory. Greater maternal emotion dysregulation was significantly related to heightened mother-infant gaze synchrony. The overall effect of maternal emotion dysregulation on mother-infant gaze synchrony was relatively more important than the effect of maternal depressive symptoms in the five tested models. Maternal emotion dysregulation fully mediated the relation between maternal depressive symptoms and mother-infant gaze synchrony. Our findings suggest that the effect of the mother's depressive symptoms on the mother-infant gaze synchrony may be mediated by the mother's emotion dysregulation.

  12. Experimental test of spatial updating models for monkey eye-head gaze shifts.

    Directory of Open Access Journals (Sweden)

    Tom J Van Grootel

    Full Text Available How the brain maintains an accurate and stable representation of visual target locations despite the occurrence of saccadic gaze shifts is a classical problem in oculomotor research. Here we test and dissociate the predictions of different conceptual models for head-unrestrained gaze-localization behavior of macaque monkeys. We adopted the double-step paradigm with rapid eye-head gaze shifts to measure localization accuracy in response to flashed visual stimuli in darkness. We presented the second target flash either before (static, or during (dynamic the first gaze displacement. In the dynamic case the brief visual flash induced a small retinal streak of up to about 20 deg at an unpredictable moment and retinal location during the eye-head gaze shift, which provides serious challenges for the gaze-control system. However, for both stimulus conditions, monkeys localized the flashed targets with accurate gaze shifts, which rules out several models of visuomotor control. First, these findings exclude the possibility that gaze-shift programming relies on retinal inputs only. Instead, they support the notion that accurate eye-head motor feedback updates the gaze-saccade coordinates. Second, in dynamic trials the visuomotor system cannot rely on the coordinates of the planned first eye-head saccade either, which rules out remapping on the basis of a predictive corollary gaze-displacement signal. Finally, because gaze-related head movements were also goal-directed, requiring continuous access to eye-in-head position, we propose that our results best support a dynamic feedback scheme for spatial updating in which visuomotor control incorporates accurate signals about instantaneous eye- and head positions rather than relative eye- and head displacements.

  13. Temperature and Coefficient of Restitution of a Table Tennis Ball

    Directory of Open Access Journals (Sweden)

    Yoonyoung Chang

    2016-01-01

    Full Text Available The coefficient of restitution (COR of a bouncing table tennis ball was measured at varying ball temperatures with a Motion Detector. It was found that there is a negative linear relationship between the COR and the temperature of the table tennis ball for temperatures ranging from 5 to 56 ̊C.

  14. Frictional torque numbers for ball cup and journal bearings

    OpenAIRE

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional torque increases to a maximum of 1.273 times the frictional torque at zero wear.

  15. Frictional torque numbers for ball cup and journal bearings

    NARCIS (Netherlands)

    Ligterink, D.J.

    1982-01-01

    Plastic bearing material wears in ball cup and journal bearings. Contact areas in the ball cup and the journal bearing increase. The frictional torque needed to rotate the ball or journal also increases. When the coefficient of friction is assumed to be constant during wearing out, the frictional t

  16. Evaluation of a low-cost open-source gaze tracker

    DEFF Research Database (Denmark)

    San Agustin, Javier; Jensen, Henrik Tomra Skovsgaard Hegner; Møllenbach, Emilie;

    2010-01-01

    This paper presents a low-cost gaze tracking system that is based on a webcam mounted close to the user's eye. The performance of the gaze tracker was evaluated in an eye-typing task using two different typing applications. Participants could type between 3.56 and 6.78 words per minute, depending...

  17. Gaze-based interaction with public displays using off-the-shelf components

    DEFF Research Database (Denmark)

    San Agustin, Javier; Hansen, John Paulin; Tall, Martin Henrik

    Eye gaze can be used to interact with high-density information presented on large displays. We have built a system employing off-the-shelf hardware components and open-source gaze tracking software that enables users to interact with an interface displayed on a 55” screen using their eye movement...

  18. Brain activation related to combinations of gaze position, visual input, and goal-directed hand movements.

    Science.gov (United States)

    Bédard, Patrick; Wu, Min; Sanes, Jerome N

    2011-06-01

    Humans reach to and acquire objects by transforming visual targets into action commands. How the brain integrates goals specified in a visual framework to signals into a suitable framework for an action plan requires clarification whether visual input, per se, interacts with gaze position to formulate action plans. To further evaluate brain control of visual-motor integration, we assessed brain activation, using functional magnetic resonance imaging. Humans performed goal-directed movements toward visible or remembered targets while fixating gaze left or right from center. We dissociated movement planning from performance using a delayed-response task and manipulated target visibility by its availability throughout the delay or blanking it 500 ms after onset. We found strong effects of gaze orientation on brain activation during planning and interactive effects of target visibility and gaze orientation on movement-related activation during performance in parietal and premotor cortices (PM), cerebellum, and basal ganglia, with more activation for rightward gaze at a visible target and no gaze modulation for movements directed toward remembered targets. These results demonstrate effects of gaze position on PM and movement-related processes and provide new information how visual signals interact with gaze position in transforming visual inputs into motor goals.

  19. Impairment of Unconscious, but Not Conscious, Gaze-Triggered Attention Orienting in Asperger's Disorder

    Science.gov (United States)

    Sato, Wataru; Uono, Shota; Okada, Takashi; Toichi, Motomi

    2010-01-01

    Impairment of joint attention represents the core clinical features of pervasive developmental disorders (PDDs), including autism and Asperger's disorder. However, experimental studies reported intact gaze-triggered attentional orienting in PDD. Since all previous studies employed supraliminal presentation of gaze stimuli, we hypothesized that…

  20. Coding gaze tracking data with chromatic gradients for VR Exposure Therapy

    DEFF Research Database (Denmark)

    Herbelin, Bruno; Grillon, Helena; De Heras Ciechomski, Pablo

    2007-01-01

    This article presents a simple and intuitive way to represent the eye-tracking data gathered during immersive virtual reality exposure therapy sessions. Eye-tracking technology is used to observe gaze movements during vir- tual reality sessions and the gaze-map chromatic gradient coding allows...

  1. Does Gaze Direction Modulate Facial Expression Processing in Children with Autism Spectrum Disorder?

    Science.gov (United States)

    Akechi, Hironori; Senju, Atsushi; Kikuchi, Yukiko; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

    2009-01-01

    Two experiments investigated whether children with autism spectrum disorder (ASD) integrate relevant communicative signals, such as gaze direction, when decoding a facial expression. In Experiment 1, typically developing children (9-14 years old; n = 14) were faster at detecting a facial expression accompanying a gaze direction with a congruent…

  2. Facial Expressions Modulate the Ontogenetic Trajectory of Gaze-Following among Monkeys

    Science.gov (United States)

    Teufel, Christoph; Gutmann, Anke; Pirow, Ralph; Fischer, Julia

    2010-01-01

    Gaze-following, the tendency to direct one's attention to locations looked at by others, is a crucial aspect of social cognition in human and nonhuman primates. Whereas the development of gaze-following has been intensely studied in human infants, its early ontogeny in nonhuman primates has received little attention. Combining longitudinal and…

  3. Fuzzy Integral-Based Gaze Control of a Robotic Head for Human Robot Interaction.

    Science.gov (United States)

    Yoo, Bum-Soo; Kim, Jong-Hwan

    2015-09-01

    During the last few decades, as a part of effort to enhance natural human robot interaction (HRI), considerable research has been carried out to develop human-like gaze control. However, most studies did not consider hardware implementation, real-time processing, and the real environment, factors that should be taken into account to achieve natural HRI. This paper proposes a fuzzy integral-based gaze control algorithm, operating in real-time and the real environment, for a robotic head. We formulate the gaze control as a multicriteria decision making problem and devise seven human gaze-inspired criteria. Partial evaluations of all candidate gaze directions are carried out with respect to the seven criteria defined from perceived visual, auditory, and internal inputs, and fuzzy measures are assigned to a power set of the criteria to reflect the user defined preference. A fuzzy integral of the partial evaluations with respect to the fuzzy measures is employed to make global evaluations of all candidate gaze directions. The global evaluation values are adjusted by applying inhibition of return and are compared with the global evaluation values of the previous gaze directions to decide the final gaze direction. The effectiveness of the proposed algorithm is demonstrated with a robotic head, developed in the Robot Intelligence Technology Laboratory at Korea Advanced Institute of Science and Technology, through three interaction scenarios and three comparison scenarios with another algorithm.

  4. Reading pleasure : Light in August and the theory of the gendered gaze

    NARCIS (Netherlands)

    Visser, [No Value

    1997-01-01

    This article discusses various components of the theory of the gendered gaze, in order to construct a framework for an analysis of how William Faulkner understood and fictionally presented the mechanism of the gaze in Light in August. Linking theory and praxis, this article explores the relationship

  5. Getting Down to Business: Talk, Gaze, and Body Orientation during Openings of Doctor-Patient Consultations.

    Science.gov (United States)

    Robinson, Jeffrey David

    1998-01-01

    Uses conversation analysis to examine how doctors' and patients' practices of gaze and body orientation organize interaction such that doctors routinely initiate the sequence wherein patients disclose their chief complaint. Finds doctors use gaze/body orientation to communicate they are preparing but not yet ready to deal with complaints--while…

  6. Children's Knowledge of Deceptive Gaze Cues and Its Relation to Their Actual Lying Behavior

    Science.gov (United States)

    McCarthy, Anjanie; Lee, Kang

    2009-01-01

    Eye gaze plays a pivotal role during communication. When interacting deceptively, it is commonly believed that the deceiver will break eye contact and look downward. We examined whether children's gaze behavior when lying is consistent with this belief. In our study, 7- to 15-year-olds and adults answered questions truthfully ("Truth" questions)…

  7. Eye can see what you want: Posterior Intraparietal Sulcus encodes the object of an actor's gaze

    NARCIS (Netherlands)

    Ramsey, R.; Cross, E.S.; Hamilton, A.F.D.C.

    2011-01-01

    In a social setting, seeing Sally look at a clock means something different to seeing her gaze longingly at a slice of chocolate cake. In both cases, her eyes and face might be turned rightward, but the information conveyed is markedly different, depending on the object of her gaze. Numerous studies

  8. The genealogical gaze: family identities and family archives in the fourteenth to seventeenth centuries

    NARCIS (Netherlands)

    Ketelaar, E.

    2009-01-01

    In Renaissance Florence, early modern England, and the Netherlands during the Golden Age the "genealogical gaze" transfigured family archives into a cultural patrimony to be preserved, expanded, and transferred to future generations. Descendants, by appropriating the object of that genealogical gaze

  9. Age-related changes in the integration of gaze direction and facial expressions of emotion.

    Science.gov (United States)

    Slessor, Gillian; Phillips, Louise H; Bull, Rebecca

    2010-08-01

    Gaze direction influences younger adults' perception of emotional expressions, with direct gaze enhancing the perception of anger and joy, while averted gaze enhances the perception of fear. Age-related declines in emotion recognition and eye-gaze processing have been reported, indicating that there may be age-related changes in the ability to integrate these facial cues. As there is evidence of a positivity bias with age, age-related difficulties integrating these cues may be greatest for negative emotions. The present research investigated age differences in the extent to which gaze direction influenced explicit perception (e.g., anger, fear and joy; Study 1) and social judgments (e.g., of approachability; Study 2) of emotion faces. Gaze direction did not influence the perception of fear in either age group. In both studies, age differences were found in the extent to which gaze direction influenced judgments of angry and joyful faces, with older adults showing less integration of gaze and emotion cues than younger adults. Age differences were greatest when interpreting angry expressions. Implications of these findings for older adults' social functioning are discussed.

  10. "Avoiding or approaching eyes"? Introversion/extraversion affects the gaze-cueing effect.

    Science.gov (United States)

    Ponari, Marta; Trojano, Luigi; Grossi, Dario; Conson, Massimiliano

    2013-08-01

    We investigated whether the extra-/introversion personality dimension can influence processing of others' eye gaze direction and emotional facial expression during a target detection task. On the basis of previous evidence showing that self-reported trait anxiety can affect gaze-cueing with emotional faces, we also verified whether trait anxiety can modulate the influence of intro-/extraversion on behavioral performance. Fearful, happy, angry or neutral faces, with either direct or averted gaze, were presented before the target appeared in spatial locations congruent or incongruent with stimuli's eye gaze direction. Results showed a significant influence of intra-/extraversion dimension on gaze-cueing effect for angry, happy, and neutral faces with averted gaze. Introverts did not show the gaze congruency effect when viewing angry expressions, but did so with happy and neutral faces; extraverts showed the opposite pattern. Importantly, the influence of intro-/extraversion on gaze-cueing was not mediated by trait anxiety. These findings demonstrated that personality differences can shape processing of interactions between relevant social signals.

  11. Impairment of Unconscious, but Not Conscious, Gaze-Triggered Attention Orienting in Asperger's Disorder

    Science.gov (United States)

    Sato, Wataru; Uono, Shota; Okada, Takashi; Toichi, Motomi

    2010-01-01

    Impairment of joint attention represents the core clinical features of pervasive developmental disorders (PDDs), including autism and Asperger's disorder. However, experimental studies reported intact gaze-triggered attentional orienting in PDD. Since all previous studies employed supraliminal presentation of gaze stimuli, we hypothesized that…

  12. How does gaze direction affect facial processing in social anxiety? -An ERP study.

    Science.gov (United States)

    Li, Dan; Yu, Fengqiong; Ye, Rong; Chen, Xingui; Xie, Xinhui; Zhu, Chunyan; Wang, Kai

    2017-02-09

    Previous behavioral studies have demonstrated an effect of eye gaze direction on the processing of emotional expressions in adults with social anxiety. However, specific brain responses to the interaction between gaze direction and facial expressions in social anxiety remain unclear. The present study aimed to explore the time course of such interaction using event-related potentials (ERPs) in participants with social anxiety. High socially anxious individuals and low socially anxious individuals were asked to identify the gender of angry or neutral faces with direct or averted gaze while their behavioral performance and electrophysiological data were monitored. We found that identification of angry faces with direct but not averted gaze elicited larger N2 amplitude in high socially anxious individuals compared to low socially anxious individuals, while identification of neutral faces did not produce any gaze modulation effect. Moreover, the N2 was correlated with increased anxiety severity upon exposure to angry faces with direct gaze. Therefore, our results suggest that gaze direction modulates the processing of threatening faces in social anxiety. The N2 component elicited by angry faces with direct gaze could be a state-dependent biomarker of social anxiety and may be an important reference biomarker for social anxiety diagnosis and intervention.

  13. Adaptive Gaze Strategies for Locomotion with Constricted Visual Field

    Directory of Open Access Journals (Sweden)

    Colas N. Authié

    2017-07-01

    Full Text Available In retinitis pigmentosa (RP, loss of peripheral visual field accounts for most difficulties encountered in visuo-motor coordination during locomotion. The purpose of this study was to accurately assess the impact of peripheral visual field loss on gaze strategies during locomotion, and identify compensatory mechanisms. Nine RP subjects presenting a central visual field limited to 10–25° in diameter, and nine healthy subjects were asked to walk in one of three directions—straight ahead to a visual target, leftward and rightward through a door frame, with or without obstacle on the way. Whole body kinematics were recorded by motion capture, and gaze direction in space was reconstructed using an eye-tracker. Changes in gaze strategies were identified in RP subjects, including extensive exploration prior to walking, frequent fixations of the ground (even knowing no obstacle was present, of door edges, essentially of the proximal one, of obstacle edge/corner, and alternating door edges fixations when approaching the door. This was associated with more frequent, sometimes larger rapid-eye-movements, larger movements, and forward tilting of the head. Despite the visual handicap, the trajectory geometry was identical between groups, with a small decrease in walking speed in RPs. These findings identify the adaptive changes in sensory-motor coordination, in order to ensure visual awareness of the surrounding, detect changes in spatial configuration, collect information for self-motion, update the postural reference frame, and update egocentric distances to environmental objects. They are of crucial importance for the design of optimized rehabilitation procedures.

  14. A New Shaping Model for Green Ceramic Balls

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The shaping quality of green ceramic balls is directly related to the efficiency and cost of later machining for the ceramic balls. Until now the shaping for green ceramic balls is still conducted by handwork. In this paper, a new shaping model for green ceramic balls was designed. In the new model, two grinding wheels with the same generator line as circular arc are mounted on symmetry, and their axes are parallel. The green ball can be put in the enveloping space formed by the two grinding wheels. The rad...

  15. Steel balls forming by cross rolling with upsetting

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2013-01-01

    Full Text Available The paper describes a process of forming four balls with a diameter of 22 mm by means of cross rolling with upsetting. The paper also presents the tool used to form semi-finished balls. Owing to the application of the finite element method (FEM, the course of the rolling process as well as temperature and strain distributions in the obtained balls could be presented. The rolling tests conducted in laboratory conditions at the Lublin University of Technology have proved that the balls produced with the developed rolling method meet the demands for grinding media used in ball mills.

  16. Lawn tennis balls, Rolling friction experiment and Trouton viscosity

    CERN Document Server

    Singh, Ankit; Kulkarni, Kaustubh; Budhraja, Abhishek; Tej, K R Sai; Sankarlingam, Satish; Biswas, Anindya Kumar

    2008-01-01

    Three lawn tennis balls were arbitrarily taken. One ball was new, one was moderately old and another was old. We have fabricated a conveyor belt set-up and measured rolling friction coefficients, $\\mu_{r}$, of the three balls as a function of their angular velocities, $\\omega$. For the new ball, quadratic fit is perfect. For the moderately old ball, linear fit is accurate. In all the three cases, from linear fits, we obtain $k_{rol}$, where, $\\mu_{r}= k_{rol} \\omega + intercept$. We deduce $k_{rol}$ theoretically also, assuming Trouton ratio as three. The experimental results and theoretical estimates are of the same order of magnitude.

  17. Looking at Eye Gaze Processing and Its Neural Correlates in Infancy--Implications for Social Development and Autism Spectrum Disorder

    Science.gov (United States)

    Hoehl, Stefanie; Reid, Vincent M.; Parise, Eugenio; Handl, Andrea; Palumbo, Letizia; Striano, Tricia

    2009-01-01

    The importance of eye gaze as a means of communication is indisputable. However, there is debate about whether there is a dedicated neural module, which functions as an eye gaze detector and when infants are able to use eye gaze cues in a referential way. The application of neuroscience methodologies to developmental psychology has provided new…

  18. Gaze shifts during dual-tasking stair descent

    OpenAIRE

    Miyasike-daSilva, Veronica; McIlroy, William E

    2016-01-01

    To investigate the role of vision in stair locomotion, young adults descended a seven-step staircase during unrestricted walking (CONTROL), and while performing a concurrent visual reaction time (RT) task displayed on a monitor. The monitor was located at either 3.5 m (HIGH) or 0.5 m (LOW) above ground level at the end of the stairway, which either restricted (HIGH) or facilitated (LOW) the view of the stairs in the lower field of view as participants walked downstairs. Downward gaze shifts (...

  19. A comprehensive gaze stabilization controller based on cerebellar internal models

    DEFF Research Database (Denmark)

    Vannucci, Lorenzo; Falotico, Egidio; Tolu, Silvia

    2017-01-01

    based on the coordination of VCR and VOR and OKR. The model, inspired by neuroscientific cerebellar theories, is provided with learning and adaptation capabilities based on internal models. We present the results for the gaze stabilization model on three sets of experiments conducted on the SABIAN robot...... and on the iCub simulator, validating the robustness of the proposed control method. The first set of experiments focused on the controller response to a set of disturbance frequencies along the vertical plane. The second shows the performances of the system under three-dimensional disturbances. The last set...

  20. A testimony to Muzil: Hervé Guibert, Foucault, and the medical gaze.

    Science.gov (United States)

    Rendell, Joanne

    2004-01-01

    Testimony to Muzil: Hervé Guibert, Michel Foucault, and the "Medical Gaze" examines the fictional/autobiographical AIDS writings of the French writer Hervé Guibert. Locating Guibert's writings alongside the work of his friend Michel Foucault, the article explores how they echo Foucault's evolving notions of the "medical gaze." The article also explores how Guilbert's narrators and Guibert himself (as writer) resist and challenge the medical gaze; a gaze which particularly in the era of AIDS has subjected, objectified, and even sometimes punished the body of the gay man. It is argued that these resistances to the gaze offer a literary extension to Foucault's later work on power and resistance strategies.

  1. Subjects and Objects of the Embodied Gaze: Abbas Kiarostami and the Real of the Individual Perspective

    Directory of Open Access Journals (Sweden)

    Gyenge Zsolt

    2016-12-01

    Full Text Available It is widely accepted that Abbas Kiarostami’s cinema revolves around the representation of the gaze. Many critics argue that he should be considered a late modernist who repeats the self-reflexive gestures of modernist European cinema decades after they were first introduced. The present paper will contradict this assertion by investigating the problematic of the Kiarostamian gaze and analyzing the perceptual side of the act of looking. I will argue that instead of focusing on the gaze of the spectator directed towards the filmic image, he exposes a gaze that is fully integrated into the reality to be captured on film. The second part of the paper will explain this by linking the concept of gaze to the Lacanian concept of the order of the Real. Finally, I will contextualize all this by discussing the Iranian director’s position between Eastern and Western traditions of representation.

  2. Interpersonal multisensory stimulation reduces the overwhelming distracting power of self-gaze: psychophysical evidence for 'engazement'.

    Science.gov (United States)

    Porciello, Giuseppina; Holmes, Brittany Serra; Liuzza, Marco Tullio; Crostella, Filippo; Aglioti, Salvatore Maria; Bufalari, Ilaria

    2014-10-20

    One's own face and gaze are never seen directly but only in a mirror. Yet, these stimuli capture attention more powerfully than others' face and gaze, suggesting the self is special for brain and behavior. Synchronous touches felt on one's own and seen on the face of others induce the sensation of including others in one's own face (enfacement). We demonstrate that enfacement may also reduce the overwhelming distracting power of self-gaze. This effect, hereafter called 'engazement', depends on the perceived physical attractiveness and inner beauty of the pair partner. Thus, we highlight for the first time the close link between enfacement and engazement by showing that changes of the self-face representation induced by facial visuo-tactile stimulation extend to gaze following, a separate process likely underpinned by different neural substrates. Moreover, although gaze following is a largely automatic, engazement is penetrable to the influence of social variables, such as positive interpersonal perception.

  3. The late positive potential indexes a role for emotion during learning of trust from eye-gaze cues. : The LPP and learning of trust from gaze

    OpenAIRE

    Manssuer, Luis; Roberts, Mark; Tipper, Steven Paul

    2015-01-01

    Gaze direction perception triggers rapid visuospatial orienting to the location observed by others. When this is congruent with the location of a target, reaction times are faster than when incongruent. Functional magnetic resonance imaging studies suggest that the non-joint attention induced by incongruent cues are experienced as more emotionally negative and this could relate to less favorable trust judgments of the faces when gaze-cues are contingent with identity. Here, we provide further...

  4. The strange flight behaviour of slowly spinning soccer balls

    Science.gov (United States)

    Mizota, Taketo; Kurogi, Kouhei; Ohya, Yuji; Okajima, Atsushi; Naruo, Takeshi; Kawamura, Yoshiyuki

    2013-05-01

    The strange three-dimensional flight behaviour of slowly spinning soccer balls is one of the most interesting and unknown phenomenon associated with the trajectories of sports balls. Many spectators have experienced numerous exciting and emotional instances while observing the curious flight behaviour of these balls. We examine the aerodynamic mechanisms of erratic ball behaviours through real flight observations, unsteady force measurements and flow pattern visualisations. The strange behaviour is elucidated by the relationship between the unsteady forces on the ball and the wake flow. The irregular changes in position for twin longitudinal vortices have already been discovered in the supercritical Reynolds number region of a sphere with a smooth surface. This finding is applicable to the strange behaviour of the flight of soccer balls with this supercritical flow. The players, spectators, and television viewers will gain greater insight into the effects of soccer ball flights.

  5. Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

    Directory of Open Access Journals (Sweden)

    Jan Carboch, Vladimir Süss, Tomas Kocib

    2014-06-01

    Full Text Available Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server. Receivers’ movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing.

  6. Mixed body- and gaze-centered coding of proprioceptive reach targets after effector movement.

    Science.gov (United States)

    Mueller, Stefanie; Fiehler, Katja

    2016-07-01

    Previous studies demonstrated that an effector movement intervening between encoding and reaching to a proprioceptive target determines the underlying reference frame: proprioceptive reach targets are represented in a gaze-independent reference frame if no movement occurs but are represented with respect to gaze after an effector movement (Mueller and Fiehler, 2014a). The present experiment explores whether an effector movement leads to a switch from a gaze-independent, body-centered reference frame to a gaze-dependent reference frame or whether a gaze-dependent reference frame is employed in addition to a gaze-independent, body-centered reference frame. Human participants were asked to reach in complete darkness to an unseen finger (proprioceptive target) of their left target hand indicated by a touch. They completed 2 conditions in which the target hand remained either stationary at the target location (stationary condition) or was actively moved to the target location, received a touch and was moved back before reaching to the target (moved condition). We dissociated the location of the movement vector relative to the body midline and to the gaze direction. Using correlation and regression analyses, we estimated the contribution of each reference frame based on horizontal reach errors in the stationary and moved conditions. Gaze-centered coding was only found in the moved condition, replicating our previous results. Body-centered coding dominated in the stationary condition while body- and gaze-centered coding contributed equally strong in the moved condition. Our results indicate a shift from body-centered to combined body- and gaze-centered coding due to an effector movement before reaching towards proprioceptive targets.

  7. Training experience in gestures affects the display of social gaze in baboons' communication with a human.

    Science.gov (United States)

    Bourjade, Marie; Canteloup, Charlotte; Meguerditchian, Adrien; Vauclair, Jacques; Gaunet, Florence

    2015-01-01

    Gaze behaviour, notably the alternation of gaze between distal objects and social partners that accompanies primates' gestural communication is considered a standard indicator of intentionality. However, the developmental precursors of gaze behaviour in primates' communication are not well understood. Here, we capitalized on the training in gestures dispensed to olive baboons (Papio anubis) as a way of manipulating individual communicative experience with humans. We aimed to delineate the effects of such a training experience on gaze behaviour displayed by the monkeys in relation with gestural requests. Using a food-requesting paradigm, we compared subjects trained in requesting gestures (i.e. trained subjects) to naïve subjects (i.e. control subjects) for their occurrences of (1) gaze behaviour, (2) requesting gestures and (3) temporal combination of gaze alternation with gestures. We found that training did not affect the frequencies of looking at the human's face, looking at food or alternating gaze. Hence, social gaze behaviour occurs independently from the amount of communicative experience with humans. However, trained baboons-gesturing more than control subjects-exhibited most gaze alternation combined with gestures, whereas control baboons did not. By reinforcing the display of gaze alternation along with gestures, we suggest that training may have served to enhance the communicative function of hand gestures. Finally, this study brings the first quantitative report of monkeys producing requesting gestures without explicit training by humans (controls). These results may open a window on the developmental mechanisms (i.e. incidental learning vs. training) underpinning gestural intentional communication in primates.

  8. Charged Q-ball dark matter from B and L direction

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jeong-Pyong; Kawasaki, Masahiro [Institute for Cosmic Ray Research, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan); Yamada, Masaki [Institute for Cosmic Ray Research, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan); Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan)

    2016-08-24

    We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of ±α{sup −1}≃±137 well before the BBN epoch and discussed how they evolve in time. We found that ion-like objects with electric charges of +O(1) are likely to become relics in the present universe, which we expect to be the dark matter. These are constrained by MICA experiment, where the trail of heavy atom-like or ion-like object in 10{sup 9} years old ancient mica crystals is not observed. We found that the allowed region for gauge mediation model parameter and reheating temperature have to be smaller than the case of the neutral Q-ball dark matter.

  9. Charged Q-ball Dark Matter from $B$ and $L$ direction

    CERN Document Server

    Hong, Jeong-Pyong; Yamada, Masaki

    2016-01-01

    We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of $\\alpha^{-1}\\simeq137$ well before the BBN epoch and discussed how they evolve in time. We found that ion-like objects with electric charges of $+O(1)$ are likely to become relics in the present universe, which we expect to be the dark matter. These are constrained by MICA experiment, where the trail of heavy atom-like or ion-like object in $10^9$ years old ancient mica crystals is not observed. We found that the allowed region for gauge mediation model parameter and reheating temperature have to be smaller than the case of the neutral Q-ball dark matter.

  10. Charged Q-ball dark matter from B and L direction

    Science.gov (United States)

    Hong, Jeong-Pyong; Kawasaki, Masahiro; Yamada, Masaki

    2016-08-01

    We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of ±α-1 simeq ±137 well before the BBN epoch and discussed how they evolve in time. We found that ion-like objects with electric charges of +O(1) are likely to become relics in the present universe, which we expect to be the dark matter. These are constrained by MICA experiment, where the trail of heavy atom-like or ion-like object in 109 years old ancient mica crystals is not observed. We found that the allowed region for gauge mediation model parameter and reheating temperature have to be smaller than the case of the neutral Q-ball dark matter.

  11. Dust ball physics and the Schwarzschild metric

    CERN Document Server

    Kassner, Klaus

    2016-01-01

    A physics-first derivation of the Schwarzschild metric is given. Gravitation is described in terms of the effects of tidal forces (or of spacetime curvature) on the volume of a small ball of test particles (a dust ball), freely falling after all particles were at rest with respect to each other initially. The possibility to express Einstein's equation this way and some of its ramifications have been enjoyably discussed by Baez and Bunn [Am. J. Phys. 73, 644 (2005)]. Since the formulation avoids the use of tensors, neither advanced tensor calculus nor sophisticated differential geometry are needed in the calculation. The derivation is not lengthy and it has visual appeal, so it may be useful in teaching.

  12. Symmetric States on the Octonionic Bloch Ball

    Science.gov (United States)

    Graydon, Matthew

    2012-02-01

    Finite-dimensional homogeneous self-dual cones arise as natural candidates for convex sets of states and effects in a variety of approaches towards understanding the foundations of quantum theory in terms of information-theoretic concepts. The positive cone of the ten-dimensional Jordan-algebraic spin factor is one particular instantiation of such a convex set in generalized frameworks for quantum theory. We consider a projection of the regular 9-simplex onto the octonionic projective line to form a highly symmetric structure of ten octonionic quantum states on the surface of the octonionic Bloch ball. A uniform subnormalization of these ten symmetric states yields a symmetric informationally complete octonionic quantum measurement. We discuss a Quantum Bayesian reformulation of octonionic quantum formalism for the description of two-dimensional physical systems. We also describe a canonical embedding of the octonionic Bloch ball into an ambient space for states in usual complex quantum theory.

  13. Collisional and collisionless expansion of Yukawa balls.

    Science.gov (United States)

    Piel, Alexander; Goree, John A

    2013-12-01

    The expansion of Yukawa balls is studied by means of molecular dynamics simulations of collisionless and collisional situations. High computation speed was achieved by using the parallel computing power of graphics processing units. When the radius of the Yukawa ball is large compared to the shielding length, the expansion process starts with the blow-off of the outermost layer. A rarefactive wave subsequently propagates radially inward at the speed of longitudinal phonons. This mechanism is fundamentally different from Coulomb explosions, which employ a self-similar expansion of the entire system. In the collisionless limit, the outer layers carry away most of the available energy. The simulations are compared with analytical estimates. In the collisional case, the expansion process can be described by a nonlinear diffusion equation that is a special case of the porous medium equation.

  14. The Neutrino Ball Model of a Quasar

    CERN Document Server

    Manka, R; Karczewska, D

    1993-01-01

    It is suggested that the nonorthodox model of a quasar as a neutrino ball described in terms of the standard model extended by adding right-handed neutrinos and the Majorana scalar field can be presented in order to explain a quasar as a body of weak interacting neutrinos. Neutrino interaction with the scalar Majorana field violates the lepton number and produces the mass splitting of the neutrino due to the sea-saw mechanism. In this model a quasar is an object which appears in the result of the first order cosmological phase transition. In this interpretation a quasar may be regarded as a ball filled with Dirac neutrinos and can be treated as a remnant of phase transition with unbroken global lepton symmetry. In this paper we study the macroscopic parameters of such a configuration. In the result the mass-radius curve M(R) for the quasar is obtained.

  15. The squint Moon and the witch ball

    Science.gov (United States)

    Berry, M. V.

    2015-06-01

    A witch ball is a reflecting sphere of glass. Looking into the disk that it subtends, the whole sky can be seen at one glance. This feature can be exploited to see and photograph the squint Moon illusion, in which the direction normal to the illuminated face of the Moon—its ‘attitude vector’—does not appear to point towards the Sun. The images of the Sun and Moon in the disk, the geodesic connecting them, the Moon’s attitude, and the squint angle (distinct from the tilt), can be calculated and simulated, for all celestial configurations and viewing inclinations. The Moon direction antipodal to the Sun, corresponding to full Moon, is a singularity of the attitude vector field, with index +1. The main features of the witch ball images also occur in other ways of imaging the squint Moon.

  16. Effect of Changing Table Tennis Ball Material from Celluloid to Plastic on the Post-Collision Ball Trajectory

    Directory of Open Access Journals (Sweden)

    Inaba Yuki

    2017-01-01

    Full Text Available The official material used in table tennis balls was changed from celluloid to plastic, a material free of celluloid, in 2014. The purpose of this study was to understand the differences and similarities in the two types of ball materials by comparing their behavior upon collision with a table. The behavior of the balls before and after collision with a table, at various initial speeds ranging from 15 to 115 km/h, was captured using high-speed cameras. Velocities and spin rates before collision and velocities after collision were computed to calculate the coefficients of restitution and friction. Based on the computed variables, the post-collision trajectories of both balls were calculated by integrating the equation of motion of the ball for simulated service, smash and drive conditions with respect to time. The coefficients of restitution were higher for the plastic balls than the celluloid ones when the initial vertical velocities were higher. The coefficients of friction were higher for plastic balls when the initial horizontal contact point velocities were slower. Because of the differences in the material characteristics, the plastic ball trajectories of services with backspin and drives with great topspin were expected to be different from those of celluloid balls. Since the extent of differences between the two ball types varied depending on the initial conditions, testing at various initial conditions was suggested for comparing and understanding the characteristics of the balls.

  17. Low-Wear Ball-Bearing Separator

    Science.gov (United States)

    Hawkinson, Elden L.

    1991-01-01

    Proposed ball-bearing separator for use in cryogenic pump stronger and more resistant to wear. Consists of molded plastic-and-metal composite ring imbued with solid lubricant and containing embedded metal ring. Obtains combination of strength and lubricity. Before molding and machining, ring includes tooling portion for handling and indexing. Molded composite blend of PTFE and fluorinated ethylene/propylene (FEP) filled with brass and bronze powder and molybdenum disulfide powder.

  18. Capillary floating and the billiard ball problem

    OpenAIRE

    Gutkin, Eugene

    2010-01-01

    We establish a connection between capillary floating in neutral equilibrium and the billiard ball problem. This allows us to reduce the question of floating in neutral equilibrium at any orientation with a prescribed contact angle for infinite homogeneous cylinders to a question about billiard caustics for their orthogonal cross-sections. We solve the billiard problem. As an application, we characterize the possible contact angles and exhibit an infinite family of real analytic non-round cyli...

  19. Gaze, dominance and humiliation in the Schreber case.

    Science.gov (United States)

    Steiner, John

    2004-04-01

    In this paper the author reviews Freud's study of Schreber's Memoirs and the Memoirs themselves from a perspective of nearly 100 years. He argues that Schreber's illness began as a melancholic depression but quickly developed paranoid features which subsequently escalated into a gross paranoia which nevertheless retained its depressive and hypochondriacal base. Finally the chaotic fragmentation became organized under the dominance of an omnipotent narcissistic organisation which led to a clinical improvement without any relinquishment of his delusional beliefs. As a subsidiary theme he examines the role of gaze in Schreber's object relations and argues that gaze was used to project into his objects, then to scrutinise the object to see if the projections had been received and tolerated, and finally as an expression of dominance. His urgent demand for relief provoked an omnipotence in his objects which he was then able triumphantly to frustrate and which ushered in a struggle over dominance in the course of which Schreber was abused and humiliated. He was unable to find an object who could contain his distress and these factors contributed to the failure to tolerate guilt and to work through his depression.

  20. Gaze contingent hologram synthesis for holographic head-mounted display

    Science.gov (United States)

    Hong, Jisoo; Kim, Youngmin; Hong, Sunghee; Shin, Choonsung; Kang, Hoonjong

    2016-03-01

    Development of display and its related technologies provides immersive visual experience with head-mounted-display (HMD). However, most available HMDs provide 3D perception only by stereopsis, lack of accommodation depth cues. Recently, holographic HMD (HHMD) arises as one viable option to resolve this problem because hologram is known to provide full set of depth cues including accommodation. Moreover, by virtue of increasing computational power, hologram synthesis from 3D object represented by point cloud can be calculated in real time even with rigorous Rayleigh-Sommerfeld diffraction formula. However, in HMD, rapid gaze change of the user requires much faster refresh rate, which means that much faster hologram synthesis is indispensable in HHMD. Because the visual acuity falls off in the visual periphery, we propose here to accelerate synthesizing hologram by differentiating density of point cloud projected on the screen. We classify the screen into multiple layers which are concentric circles with different radii, where the center is aligned with gaze of user. Layer with smaller radius is closer to the region of interest, hence, assigned with higher density of point cloud. Because the computation time is directly related to the number of points in point cloud, we can accelerate synthesizing hologram by lowering density of point cloud in the visual periphery. Cognitive study reveals that user cannot discriminate those degradation in the visual periphery if the parameters are properly designed. Prototype HHMD system will be provided for verifying the feasibility of our method, and detailed design scheme will be discussed.

  1. Looking ahead: anticipatory gaze and motor ability in infancy.

    Directory of Open Access Journals (Sweden)

    Ettore Ambrosini

    Full Text Available The present study asks when infants are able to selectively anticipate the goals of observed actions, and how this ability relates to infants' own abilities to produce those specific actions. Using eye-tracking technology to measure on-line anticipation, 6-, 8- and 10-month-old infants and a control group of adults were tested while observing an adult reach with a whole hand grasp, a precision grasp or a closed fist towards one of two different sized objects. The same infants were also given a comparable action production task. All infants showed proactive gaze to the whole hand grasps, with increased degrees of proactivity in the older groups. Gaze proactivity to the precision grasps, however, was present from 8 months of age. Moreover, the infants' ability in performing precision grasping strongly predicted their ability in using the actor's hand shape cues to differentially anticipate the goal of the observed action, even when age was partialled out. The results are discussed in terms of the specificity of action anticipation, and the fine-grained relationship between action production and action perception.

  2. Gaze direction affects visuo-spatial short-term memory.

    Science.gov (United States)

    Carlei, Christophe; Kerzel, Dirk

    2014-10-01

    Hemispheric asymmetries were investigated by changing the horizontal position of stimuli that had to be remembered in a visuo-spatial short-term memory task. Observers looked at matrices containing a variable number of filled squares on the left or right side of the screen center. At stimulus offset, participants reproduced the positions of the filled squares in an empty response matrix. Stimulus and response matrices were presented in the same quadrant. We observed that memory performance was better when the matrices were shown on the left side of the screen. We distinguished between recall strategies that relied on visual or non-visual (verbal) cues and found that the effect of gaze position occurred more reliably in participants using visual recall strategies. Overall, the results show that there is a solid enhancement of visuo-spatial short-term memory when observers look to the left. In contrast, vertical position had no influence on performance. We suggest that unilateral gaze to the left activates centers in the right hemisphere contributing to visuo-spatial memory. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Following student gaze patterns in physical science lectures

    Science.gov (United States)

    Rosengrant, David; Hearrington, Doug; Alvarado, Kerriann; Keeble, Danielle

    2012-02-01

    This study investigates the gaze patterns of undergraduate college students attending a lecture-based physical science class to better understand the relationships between gaze and focus patterns and student attention during class. The investigators used a new eye-tracking product; Tobii Glasses. The glasses eliminate the need for subjects to focus on a computer screen or carry around a backpack-sized recording device, thus giving an investigator the ability to study a broader range of research questions. This investigation includes what students focus on in the classroom (i.e. demonstrations, instructor, notes, board work, and presentations) during a normal lecture, what diverts attention away from being on task as well as what keeps a subject on task. We report on the findings from 8 subjects during physical science lectures designed for future elementary school teachers. We found that students tended not to focus on the instructor for most parts of the lecture but rather the information, particularly new information presented on PowerPoint slides. Finally, we found that location in the classroom also impacted students' attention spans due to more distractors.

  4. DIAGNOSIS OF MYASTHENIA GRAVIS USING FUZZY GAZE TRACKING SOFTWARE

    Directory of Open Access Journals (Sweden)

    Javad Rasti

    2015-04-01

    Full Text Available Myasthenia Gravis (MG is an autoimmune disorder, which may lead to paralysis and even death if not treated on time. One of its primary symptoms is severe muscular weakness, initially arising in the eye muscles. Testing the mobility of the eyeball can help in early detection of MG. In this study, software was designed to analyze the ability of the eye muscles to focus in various directions, thus estimating the MG risk. Progressive weakness in gazing at the directions prompted by the software can reveal abnormal fatigue of the eye muscles, which is an alert sign for MG. To assess the user’s ability to keep gazing at a specified direction, a fuzzy algorithm was applied to images of the user’s eyes to determine the position of the iris in relation to the sclera. The results of the tests performed on 18 healthy volunteers and 18 volunteers in early stages of MG confirmed the validity of the suggested software.

  5. Gaze and eye-tracking solutions for psychological research.

    Science.gov (United States)

    Mele, Maria Laura; Federici, Stefano

    2012-08-01

    Eye-tracking technology is a growing field used to detect eye movements and analyze human processing of visual information for interactive and diagnostic applications. Different domains in scientific research such as neuroscience, experimental psychology, computer science and human factors can benefit from eye-tracking methods and techniques to unobtrusively investigate the quantitative evidence underlying visual processes. In order to meet the experimental requirements concerning the variety of application fields, different gaze- and eye-tracking solutions using high-speed cameras are being developed (e.g., eye-tracking glasses, head-mounted or desk-mounted systems), which are also compatible with other analysis devices such as magnetic resonance imaging. This work presents an overview of the main application fields of eye-tracking methodology in psychological research. In particular, two innovative solutions will be shown: (1) the SMI RED-M eye-tracker, a high performance portable remote eye-tracker suitable for different settings, that requires maximum mobility and flexibility; (2) a wearable mobile gaze-tracking device--the SMI eye-tracking glasses--which is suitable for real-world and virtual environment research. For each kind of technology, the functions and different possibilities of application in experimental psychology will be described by focusing on some examples of experimental tasks (i.e., visual search, reading, natural tasks, scene viewing and other information processing) and theoretical approaches (e.g., embodied cognition).

  6. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

    Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

  7. Modeling on the Effect of Coal Loads on Kinetic Energy of Balls for Ball Mills

    Directory of Open Access Journals (Sweden)

    Yan Bai

    2015-07-01

    Full Text Available This paper presents a solution for the detection and control of coal loads that is more accurate and convenient than those currently used. To date, no research has addressed the use of a grinding medium as the controlled parameter. To improve the accuracy of the coal load detection based on the kinetic energy of balls in a tubular ball mill, a Discrete Element Method (DEM model for ball kinematics based on coal loads is proposed. The operating process for a ball mill and the ball motion, as influenced by the coal quality and the coal load, was analyzed carefully. The relationship between the operating efficiency of a coal pulverizing system, coal loads, and the balls’ kinetic energy was obtained. Origin and Matlab were utilized to draw the variation of parameters with increasing coal loads in the projectile and cascading motion states. The parameters include the balls’ real-time kinetic energy, the friction energy consumption, and the mill’s total work. Meanwhile, a method of balanced adjacent degree and a physical experiment were proposed to verify the considerable effect of the balls’ kinetic energy on coal loads. The model and experiment results indicate that a coal load control method based on the balls’ kinetic energy is therefore feasible for the optimized operation of a coal pulverizing system.

  8. Synthesis of aluminum nitride powders from a plasma-assisted ball milled precursor through carbothermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhi-jie [Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Dai, Le-yang [Marine Engineering Institute, Jimei University, Xiamen 361021 (China); Yang, De-zheng; Wang, Sen [Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Zhang, Bao-jian [Marine Engineering Institute, Jimei University, Xiamen 361021 (China); Wang, Wen-chun, E-mail: wangwenc@dlut.edu.cn [Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Cheng, Tie-han [Pinggao Group Co. Ltd., State Grid Corporation of China, Pingdingshan 467000 (China)

    2015-01-15

    Highlights: • A novel and high efficiency synthesizing AlN powders method combining mechanical ball milling and DBDP has been developed. • The particle size, the crystallite size, the lattice distortion, the morphology of Al{sub 2}O{sub 3} powders, and the AlN conversion rate are investigated and compared under the ball milled Al{sub 2}O{sub 3} powders with DBDP and without DBDP. • The ball milled Al{sub 2}O{sub 3} powders with DBDP have small spherical structure morphology with very fine particles size and high specific surface area, which result in a higher chemical efficiency and a higher AlN conversion rate at lower thermal temperature. - Abstract: In this paper, aluminum nitride (AlN) powers have been produced with a novel and high efficiency method by thermal annealing at 1100–1600 °C of alumina (Al{sub 2}O{sub 3}) powders which were previously ball milled for various time up to 40 h with and without the assistant of dielectric barrier discharge plasma (DBDP). The ball milled Al{sub 2}O{sub 3} powders with DBDP and without DBDP and the corresponding synthesized AlN powers are characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscopy. From the characteristics of the ball milled Al{sub 2}O{sub 3} powders with DBDP and without DBDP, it can be seen that the ball milled Al{sub 2}O{sub 3} powders with DBDP have small spherical structure morphology with very fine particles size and high specific surface area, which result in a higher chemical efficiency and a higher AlN conversion rate at lower thermal temperature. Meanwhile, the synthesized AlN powders can be known as hexagonal AlN with fine crystal morphology and irregular lump-like structure, and have uniform distribution with the average particle size of about between 500 nm and 1000 nm. This provides an important method for fabricating ultra fine powders and synthesizing nitrogen compounds.

  9. Trait Anxiety Impacts the Perceived Gaze Direction of Fearful But Not Angry Faces

    Directory of Open Access Journals (Sweden)

    Zhonghua Hu

    2017-07-01

    Full Text Available Facial expression and gaze direction play an important role in social communication. Previous research has demonstrated the perception of anger is enhanced by direct gaze, whereas, it is unclear whether perception of fear is enhanced by averted gaze. In addition, previous research has shown the anxiety affects the processing of facial expression and gaze direction, but hasn’t measured or controlled for depression. As a result, firm conclusions cannot be made regarding the impact of individual differences in anxiety and depression on perceptions of face expressions and gaze direction. The current study attempted to reexamine the effect of the anxiety level on the processing of facial expressions and gaze direction by matching participants on depression scores. A reliable psychophysical index of the range of eye gaze angles judged as being directed at oneself [the cone of direct gaze (CoDG] was used as the dependent variable in this study. Participants were stratified into high/low trait anxiety groups and asked to judge the gaze of angry, fearful, and neutral faces across a range of gaze directions. The result showed: (1 the perception of gaze direction was influenced by facial expression and this was modulated by trait anxiety. For the high trait anxiety group, the CoDG for angry expressions was wider than for fearful and neutral expressions, and no significant difference emerged between fearful and neutral expressions; For the low trait anxiety group, the CoDG for both angry and fearful expressions was wider than for neutral, and no significant difference emerged between angry and fearful expressions. (2 Trait anxiety modulated the perception of gaze direction only in the fearful condition, such that the fearful CoDG for the high trait anxiety group was narrower than the low trait anxiety group. This demonstrated that anxiety distinctly affected gaze perception in expressions that convey threat (angry, fearful, such that a high trait anxiety

  10. Aerodynamics in the classroom and at the ball park

    Science.gov (United States)

    Cross, Rod

    2012-04-01

    Experiments suitable for classroom projects or demonstrations are described concerning the aerodynamics of polystyrene balls. A light ball with sufficient backspin can curve vertically upward through the air, defying gravity and providing a dramatic visual demonstration of the Magnus effect. A ball projected with backspin can also curve downward with a vertical acceleration greater than that due to gravity if the Magnus force is negative. These effects were investigated by filming the flight of balls projected in an approximately horizontal direction so that the lift and drag forces could be easily measured. The balls were also fitted with artificial raised seams and projected with backspin toward a vertical target in order to measure the sideways deflection over a known horizontal distance. It was found that (a) a ball with a seam on one side can deflect either left or right depending on its launch speed and (b) a ball with a baseball seam can also deflect sideways even when there is no sideways component of the drag or lift forces acting on the ball. Depending on the orientations of the seam and the spin axis, a sideways force on a baseball can arise either if there is rough patch on one side of the ball or if there is a smooth patch. A scuff ball with a rough patch on one side is illegal in baseball. The effect of a smooth patch is a surprising new observation.

  11. Biomechanics of Heading a Soccer Ball: Implications for Player Safety

    Directory of Open Access Journals (Sweden)

    Charles F. Babbs

    2001-01-01

    Full Text Available To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton�s second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player�s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater “touch” and “playability”, measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  12. Biomechanics of heading a soccer ball: implications for player safety.

    Science.gov (United States)

    Babbs, C F

    2001-08-08

    To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton's second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player"s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater "touch" and "playability", measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  13. Quantifying naturalistic social gaze in fragile X syndrome using a novel eye tracking paradigm.

    Science.gov (United States)

    Hall, Scott S; Frank, Michael C; Pusiol, Guido T; Farzin, Faraz; Lightbody, Amy A; Reiss, Allan L

    2015-10-01

    A hallmark behavioral feature of fragile X syndrome (FXS) is the propensity for individuals with the syndrome to exhibit significant impairments in social gaze during interactions with others. However, previous studies employing eye tracking methodology to investigate this phenomenon have been limited to presenting static photographs or videos of social interactions rather than employing a real-life social partner. To improve upon previous studies, we used a customized eye tracking configuration to quantify the social gaze of 51 individuals with FXS and 19 controls, aged 14-28 years, while they engaged in a naturalistic face-to-face social interaction with a female experimenter. Importantly, our control group was matched to the FXS group on age, developmental functioning, and degree of autistic symptomatology. Results showed that participants with FXS spent significantly less time looking at the face and had shorter episodes (and longer inter-episodes) of social gaze than controls. Regression analyses indicated that communication ability predicted higher levels of social gaze in individuals with FXS, but not in controls. Conversely, degree of autistic symptoms predicted lower levels of social gaze in controls, but not in individuals with FXS. Taken together, these data indicate that naturalistic social gaze in FXS can be measured objectively using existing eye tracking technology during face-to-face social interactions. Given that impairments in social gaze were specific to FXS, this paradigm could be employed as an objective and ecologically valid outcome measure in ongoing Phase II/Phase III clinical trials of FXS-specific interventions.

  14. All eyes on me?! Social anxiety and self-directed perception of eye gaze.

    Science.gov (United States)

    Schulze, Lars; Lobmaier, Janek S; Arnold, Manuel; Renneberg, Babette

    2013-01-01

    To date, only little is known about the self-directed perception and processing of subtle gaze cues in social anxiety that might however contribute to excessive feelings of being looked at by others. Using a web-based approach, participants (n=174) were asked whether or not briefly (300 ms) presented facial expressions modulated in gaze direction (0°, 2°, 4°, 6°, 8°) and valence (angry, fearful, happy, neutral) were directed at them. The results demonstrate a positive, linear relationship between self-reported social anxiety and stronger self-directed perception of others' gaze directions, particularly for negative (angry, fearful) and neutral expressions. Furthermore, faster responding was found for gaze more clearly directed at socially anxious individuals (0°, 2°, and 4°) suggesting a tendency to avoid direct gaze. In sum, the results illustrate an altered self-directed perception of subtle gaze cues. The possibly amplifying effects of social stress on biased self-directed perception of eye gaze are discussed.

  15. Difference between visually and electrically evoked gaze saccades disclosed by altering the head moment of inertia.

    Science.gov (United States)

    Coimbra, A J; Lefèvre, P; Missal, M; Olivier, E

    2000-02-01

    Differences between gaze shifts evoked by collicular electrical stimulation and those triggered by the presentation of a visual stimulus were studied in head-free cats by increasing the head moment of inertia. This maneuver modified the dynamics of these two types of gaze shifts by slowing down head movements. Such an increase in the head moment of inertia did not affect the metrics of visually evoked gaze saccades because their duration was precisely adjusted to compensate for these changes in movement dynamics. In contrast, the duration of electrically evoked gaze shifts remained constant irrespective of the head moment of inertia, and therefore their amplitude was significantly reduced. These results suggest that visually and electrically evoked gaze saccades are controlled by different mechanisms. Whereas the accuracy of visually evoked saccades is likely to be assured by on-line feedback information, the absence of duration adjustment in electrically evoked gaze shifts suggests that feedback information necessary to maintain their metrics is not accessible or is corrupted during collicular stimulation. This is of great importance when these two types of movements are compared to infer the role of the superior colliculus in the control of orienting gaze shifts.

  16. Gaze-cueing requires intact face processing - Insights from acquired prosopagnosia.

    Science.gov (United States)

    Burra, Nicolas; Kerzel, Dirk; Ramon, Meike

    2017-04-01

    Gaze-cueing is the automatic spatial orienting of attention in the direction of perceived gaze. Participants respond faster to targets located at positions congruent with the direction of gaze, compared to incongruent ones (gaze cueing effect, GCE). However, it still remains unclear whether its occurrence depends on intact integration of information from the entire eye region or face, rather than simply the presence of the eyes per se. To address this question, we investigated the GCE in PS, an extensively studied case of pure acquired prosopagnosia. In our gaze-cueing paradigm, we manipulated the duration at which cues were presented (70ms vs. 400ms) and the availability of facial information (full-face vs. eyes-only). For 70ms cue duration, we found a context-dependent dissociation between PS and controls: PS showed a GCE for eyes-only stimuli, whereas controls showed a GCE only for full-face stimuli. For 400ms cue duration, PS showed gaze-cueing independently of stimulus context, whereas in healthy controls a GCE again emerged only for full-face stimuli. Our findings suggest that attentional deployment based on the gaze direction of briefly presented faces requires intact processing of facial information, which affords salience to the eye region. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Spontaneous social orienting and gaze following in ringtailed lemurs (Lemur catta).

    Science.gov (United States)

    Shepherd, Stephen V; Platt, Michael L

    2008-01-01

    Both human and nonhuman primates preferentially orient toward other individuals and follow gaze in controlled environments. Precisely where any animal looks during natural behavior, however, remains unknown. We used a novel telemetric gaze-tracking system to record orienting behavior of ringtailed lemurs (Lemur catta) interacting with a naturalistic environment. We here provide the first evidence that ringtailed lemurs, group-living prosimian primates, preferentially gaze towards other individuals and, moreover, follow other lemurs' gaze while freely moving and interacting in naturalistic social and ecological environments. Our results support the hypothesis that stem primates were capable of orienting toward and following the attention of other individuals. Such abilities may have enabled the evolution of more complex social behavior and cognition, including theory of mind and language, which require spontaneous attention sharing. This is the first study to use telemetric eye-tracking to quantitatively monitor gaze in any nonhuman animal during locomotion, feeding, and social interaction. Moreover, this is the first demonstration of gaze following by a prosimian primate and the first to report gaze following during spontaneous interaction in naturalistic social environments.

  18. Vestibulo-ocular reflex suppression during head-fixed saccades reveals gaze feedback control.

    Science.gov (United States)

    Daye, Pierre M; Roberts, Dale C; Zee, David S; Optican, Lance M

    2015-01-21

    Previous experiments have shown that the vestibulo-ocular reflex (VOR) is partially suppressed during large head-free gaze (gaze = eye-in-head + head-in-space) shifts when both the eyes and head are moving actively, on a fixed body, or when the eyes are moving actively and the head passively on a fixed body. We tested, in human subjects, the hypothesis that the VOR is also suppressed during gaze saccades made with en bloc, head and body together, rotations. Subjects made saccades by following a target light. During some trials, the chair rotated so as to move the entire body passively before, during, or after a saccade. The modulation of the VOR was a function of both saccade amplitude and the time of the head perturbation relative to saccade onset. Despite the perturbation, gaze remained accurate. Thus, VOR modulation is similar when gaze changes are programmed for the eyes alone or for the eyes and head moving together. We propose that the brain always programs a change in gaze using feedback based on gaze and head signals, rather than on separate eye and head trajectories.

  19. Gaze-Contingent Music Reward Therapy for Social Anxiety Disorder: A Randomized Controlled Trial.

    Science.gov (United States)

    Lazarov, Amit; Pine, Daniel S; Bar-Haim, Yair

    2017-07-01

    Patients with social anxiety disorder exhibit increased attentional dwelling on social threats, providing a viable target for therapeutics. This randomized controlled trial examined the efficacy of a novel gaze-contingent music reward therapy for social anxiety disorder designed to reduce attention dwelling on threats. Forty patients with social anxiety disorder were randomly assigned to eight sessions of either gaze-contingent music reward therapy, designed to divert patients' gaze toward neutral stimuli rather than threat stimuli, or to a control condition. Clinician and self-report measures of social anxiety were acquired pretreatment, posttreatment, and at 3-month follow-up. Dwell time on socially threatening faces was assessed during the training sessions and at pre- and posttreatment. Gaze-contingent music reward therapy yielded greater reductions of symptoms of social anxiety disorder than the control condition on both clinician-rated and self-reported measures. Therapeutic effects were maintained at follow-up. Gaze-contingent music reward therapy, but not the control condition, also reduced dwell time on threat, which partially mediated clinical effects. Finally, gaze-contingent music reward therapy, but not the control condition, also altered dwell time on socially threatening faces not used in training, reflecting near-transfer training generalization. This is the first randomized controlled trial to examine a gaze-contingent intervention in social anxiety disorder. The results demonstrate target engagement and clinical effects. This study sets the stage for larger randomized controlled trials and testing in other emotional disorders.

  20. Speaking and Listening with the Eyes: Gaze Signaling during Dyadic Interactions.

    Science.gov (United States)

    Ho, Simon; Foulsham, Tom; Kingstone, Alan

    2015-01-01

    Cognitive scientists have long been interested in the role that eye gaze plays in social interactions. Previous research suggests that gaze acts as a signaling mechanism and can be used to control turn-taking behaviour. However, early research on this topic employed methods of analysis that aggregated gaze information across an entire trial (or trials), which masks any temporal dynamics that may exist in social interactions. More recently, attempts have been made to understand the temporal characteristics of social gaze but little research has been conducted in a natural setting with two interacting participants. The present study combines a temporally sensitive analysis technique with modern eye tracking technology to 1) validate the overall results from earlier aggregated analyses and 2) provide insight into the specific moment-to-moment temporal characteristics of turn-taking behaviour in a natural setting. Dyads played two social guessing games (20 Questions and Heads Up) while their eyes were tracked. Our general results are in line with past aggregated data, and using cross-correlational analysis on the specific gaze and speech signals of both participants we found that 1) speakers end their turn with direct gaze at the listener and 2) the listener in turn begins to speak with averted gaze. Convergent with theoretical models of social interaction, our data suggest that eye gaze can be used to signal both the end and the beginning of a speaking turn during a social interaction. The present study offers insight into the temporal dynamics of live dyadic interactions and also provides a new method of analysis for eye gaze data when temporal relationships are of interest.

  1. Photographic but not line-drawn faces show early perceptual neural sensitivity to eye gaze direction

    Directory of Open Access Journals (Sweden)

    Alejandra eRossi

    2015-04-01

    Full Text Available Our brains readily decode facial movements and changes in social attention, reflected in earlier and larger N170 event-related potentials (ERPs to viewing gaze aversions vs. direct gaze in real faces (Puce et al. 2000. In contrast, gaze aversions in line-drawn faces do not produce these N170 differences (Rossi et al., 2014, suggesting that physical stimulus properties or experimental context may drive these effects. Here we investigated the role of stimulus-induced context on neurophysiological responses to dynamic gaze. Sixteen healthy adults viewed line-drawn and real faces, with dynamic eye aversion and direct gaze transitions, and control stimuli (scrambled arrays and checkerboards while continuous electroencephalographic (EEG activity was recorded. EEG data from 2 temporo-occipital clusters of 9 electrodes in each hemisphere where N170 activity is known to be maximal were selected for analysis. N170 peak amplitude and latency, and temporal dynamics from event-related spectral perturbations (ERSPs were measured in 16 healthy subjects. Real faces generated larger N170s for averted vs. direct gaze motion, however, N170s to real and direct gaze were as large as those to respective controls. N170 amplitude did not differ across line-drawn gaze changes. Overall, bilateral mean gamma power changes for faces relative to control stimuli occurred between 150-350 ms, potentially reflecting signal detection of facial motion.Our data indicate that experimental context does not drive N170 differences to viewed gaze changes. Low-level stimulus properties, such as the high sclera/iris contrast change in real eyes likely drive the N170 changes to viewed aversive movements.

  2. Speaking and Listening with the Eyes: Gaze Signaling during Dyadic Interactions.

    Directory of Open Access Journals (Sweden)

    Simon Ho

    Full Text Available Cognitive scientists have long been interested in the role that eye gaze plays in social interactions. Previous research suggests that gaze acts as a signaling mechanism and can be used to control turn-taking behaviour. However, early research on this topic employed methods of analysis that aggregated gaze information across an entire trial (or trials, which masks any temporal dynamics that may exist in social interactions. More recently, attempts have been made to understand the temporal characteristics of social gaze but little research has been conducted in a natural setting with two interacting participants. The present study combines a temporally sensitive analysis technique with modern eye tracking technology to 1 validate the overall results from earlier aggregated analyses and 2 provide insight into the specific moment-to-moment temporal characteristics of turn-taking behaviour in a natural setting. Dyads played two social guessing games (20 Questions and Heads Up while their eyes were tracked. Our general results are in line with past aggregated data, and using cross-correlational analysis on the specific gaze and speech signals of both participants we found that 1 speakers end their turn with direct gaze at the listener and 2 the listener in turn begins to speak with averted gaze. Convergent with theoretical models of social interaction, our data suggest that eye gaze can be used to signal both the end and the beginning of a speaking turn during a social interaction. The present study offers insight into the temporal dynamics of live dyadic interactions and also provides a new method of analysis for eye gaze data when temporal relationships are of interest.

  3. Can Speaker Gaze Modulate Syntactic Structuring and Thematic Role Assignment during Spoken Sentence Comprehension?

    Science.gov (United States)

    Knoeferle, Pia; Kreysa, Helene

    2012-01-01

    During comprehension, a listener can rapidly follow a frontally seated speaker's gaze to an object before its mention, a behavior which can shorten latencies in speeded sentence verification. However, the robustness of gaze-following, its interaction with core comprehension processes such as syntactic structuring, and the persistence of its effects are unclear. In two "visual-world" eye-tracking experiments participants watched a video of a speaker, seated at an angle, describing transitive (non-depicted) actions between two of three Second Life characters on a computer screen. Sentences were in German and had either subject(NP1)-verb-object(NP2) or object(NP1)-verb-subject(NP2) structure; the speaker either shifted gaze to the NP2 character or was obscured. Several seconds later, participants verified either the sentence referents or their role relations. When participants had seen the speaker's gaze shift, they anticipated the NP2 character before its mention and earlier than when the speaker was obscured. This effect was more pronounced for SVO than OVS sentences in both tasks. Interactions of speaker gaze and sentence structure were more pervasive in role-relations verification: participants verified the role relations faster for SVO than OVS sentences, and faster when they had seen the speaker shift gaze than when the speaker was obscured. When sentence and template role-relations matched, gaze-following even eliminated the SVO-OVS response-time differences. Thus, gaze-following is robust even when the speaker is seated at an angle to the listener; it varies depending on the syntactic structure and thematic role relations conveyed by a sentence; and its effects can extend to delayed post-sentence comprehension processes. These results suggest that speaker gaze effects contribute pervasively to visual attention and comprehension processes and should thus be accommodated by accounts of situated language comprehension.

  4. Can speaker gaze modulate syntactic structuring and thematic role assignment during spoken sentence comprehension?

    Directory of Open Access Journals (Sweden)

    Pia eKnoeferle

    2012-12-01

    Full Text Available During comprehension, a listener can rapidly follow a frontally-seated speaker's gaze to an object before its mention, a behavior which can shorten latencies in speeded sentence verification. However, the robustness of gaze-following, its interaction with core comprehension processes such as syntactic structuring, and the persistence of its effects are unclear. In two ``visual-world'' eye-tracking experiments participants watched a video of a speaker, seated at an angle, describing transitive (non-depicted actions between two of three Second Life characters on a computer screen. Sentences were in German and had either subject(NP1-verb-object(NP2 or object(NP1-verb-subject(NP2 structure; the speaker either shifted gaze to the NP2 character or was obscured. Several seconds later,participants verified either the sentence referents or their role relations. When participants had seen the speaker's gaze shift, they anticipated the NP2 character before its mention and earlier than when the speaker was obscured. This effect was more pronounced for SVO than OVS sentences in both tasks. Interactions of speaker gaze and sentence structure were more pervasive in role-relations verification: Participants verified the role relations faster for SVO than OVS sentences, and faster when they had seen the speaker shift gaze than when the speaker was obscured. When sentence and template role relations matched, gaze-following even eliminated the SVO-OVS response time differences. Thus, gaze-following is robust even when the speaker is seated at an angle to the listener; it varies depending on the syntactic structure and thematic role relations conveyed by a sentence; and its effects can extend to delayed post-sentence comprehension processes. These results suggest that speaker gaze effects contribute pervasively to visual attention and comprehension processes and should thus be accommodated by accounts of situated language comprehension.

  5. Photographic but not line-drawn faces show early perceptual neural sensitivity to eye gaze direction.

    Science.gov (United States)

    Rossi, Alejandra; Parada, Francisco J; Latinus, Marianne; Puce, Aina

    2015-01-01

    Our brains readily decode facial movements and changes in social attention, reflected in earlier and larger N170 event-related potentials (ERPs) to viewing gaze aversions vs. direct gaze in real faces (Puce et al., 2000). In contrast, gaze aversions in line-drawn faces do not produce these N170 differences (Rossi et al., 2014), suggesting that physical stimulus properties or experimental context may drive these effects. Here we investigated the role of stimulus-induced context on neurophysiological responses to dynamic gaze. Sixteen healthy adults viewed line-drawn and real faces, with dynamic eye aversion and direct gaze transitions, and control stimuli (scrambled arrays and checkerboards) while continuous electroencephalographic (EEG) activity was recorded. EEG data from 2 temporo-occipital clusters of 9 electrodes in each hemisphere where N170 activity is known to be maximal were selected for analysis. N170 peak amplitude and latency, and temporal dynamics from Event-Related Spectral Perturbations (ERSPs) were measured in 16 healthy subjects. Real faces generated larger N170s for averted vs. direct gaze motion, however, N170s to real and direct gaze were as large as those to respective controls. N170 amplitude did not differ across line-drawn gaze changes. Overall, bilateral mean gamma power changes for faces relative to control stimuli occurred between 150-350 ms, potentially reflecting signal detection of facial motion. Our data indicate that experimental context does not drive N170 differences to viewed gaze changes. Low-level stimulus properties, such as the high sclera/iris contrast change in real eyes likely drive the N170 changes to viewed aversive movements.

  6. A real-time gaze position estimation method based on a 3-D eye model.

    Science.gov (United States)

    Park, Kang Ryoung

    2007-02-01

    This paper proposes a new gaze-detection method based on a 3-D eye position and the gaze vector of the human eyeball. Seven new developments compared to previous works are presented. First, a method of using three camera systems, i.e., one wide-view camera and two narrow-view cameras, is proposed. The narrow-view cameras use autozooming, focusing, panning, and tilting procedures (based on the detected 3-D eye feature position) for gaze detection. This allows for natural head and eye movement by users. Second, in previous conventional gaze-detection research, one or multiple illuminators were used. These studies did not consider specular reflection (SR) problems, which were caused by the illuminators when working with users who wore glasses. To solve this problem, a method based on dual illuminators is proposed in this paper. Third, the proposed method does not require user-dependent calibration, so all procedures for detecting gaze position operate automatically without human intervention. Fourth, the intrinsic characteristics of the human eye, such as the disparity between the pupillary and the visual axes in order to obtain accurate gaze positions, are considered. Fifth, all the coordinates obtained by the left and right narrow-view cameras, as well as the wide-view camera coordinates and the monitor coordinates, are unified. This simplifies the complex 3-D converting calculation and allows for calculation of the 3-D feature position and gaze position on the monitor. Sixth, to upgrade eye-detection performance when using a wide-view camera, the adaptive-selection method is used. This involves an IR-LED on/off scheme, an AdaBoost classifier, and a principle component analysis method based on the number of SR elements. Finally, the proposed method uses an eigenvector matrix (instead of simply averaging six gaze vectors) in order to obtain a more accurate final gaze vector that can compensate for noise. Experimental results show that the root mean square error of

  7. Are Gaze Shifts a Key to a Translator’s Text Segmentation?

    DEFF Research Database (Denmark)

    Lykke Jakobsen, Arnt

    2016-01-01

    the feasibility of identifying segments, understood as processing units, on the basis of gaze shifts, and to inquire into what motivates gaze shifts. It also seeks to illustrate how much our interpretation of gaze representations, not least suboptimal representations, depend on a theory of reading.......? And do such shifts give us more accurate information about segmentation or more information than keystroke intervals? Using a rather poorly calibrated recording of just one translator’s translation of a single sentence (within a longer task) for illustration, the paper seeks to tentatively explore...

  8. Vestibulo-Ocular Reflex Suppression during Head-Fixed Saccades Reveals Gaze Feedback Control

    OpenAIRE

    Daye, Pierre M.; Dale C Roberts; David S Zee; Optican, Lance M.

    2015-01-01

    Previous experiments have shown that the vestibulo-ocular reflex (VOR) is partially suppressed during large head-free gaze (gaze = eye-in-head + head-in-space) shifts when both the eyes and head are moving actively, on a fixed body, or when the eyes are moving actively and the head passively on a fixed body. We tested, in human subjects, the hypothesis that the VOR is also suppressed during gaze saccades made with en bloc, head and body together, rotations. Subjects made saccades by following...

  9. The methodology of composing the exercises system with fit balls.

    Directory of Open Access Journals (Sweden)

    Voronov N.P.

    2011-02-01

    Full Text Available The original methodology of composing the exercises system with fit balls was considered. More than 10 publications were analysed. On the lesson with fit balls the problem was revealed. In the experiment took part 30 students at the age from 18 till 21. All the famous exercises were systematized. As a result, a big attractiveness and assimilability of the proposed complex was revealed. The effectiveness of the complex of physical exercises with fit balls for students was proved.

  10. Multisensory perception and action in 3-ball cascade juggling

    OpenAIRE

    Sánchez García, Raúl; Hayes, S J; Williams, A M; Bennett, S. J.

    2013-01-01

    Multisensory perception and action in 3-ball cascade juggling was investigated in intermediate-skilled performers by manipulating vision (full or lower field restricted) or ball weight (equal or different). There were main effects for both independent variables but no interactions. Manipulation of ball weight had a more pervasive effect on performance outcome, as well as central tendency and dispersion of kinematic measures of the juggling action. A common finding to both manipulations was th...

  11. Following mechanical activation of salbutamol sulphate during ball-milling with isothermal calorimetry.

    Science.gov (United States)

    Gaisford, Simon; Dennison, Mansa; Tawfik, Mahmoud; Jones, Matthew D

    2010-06-30

    Formulation of actives for pulmonary delivery with dry powder inhaler devices frequently requires a particle size reduction step. The high-energy forces imparted to a material during milling, as well as reducing particle size, can cause a significant change in physicochemical properties, in particular mechanical activation of the surface (manifested as generation of amorphous regions) which can affect formulated product performance. It is not clear whether particle size reduction occurs prior to, or concomitantly with, generation of amorphous content. In this study the formation of amorphous content with time in crystalline salbutamol sulphate was quantified with isothermal gas perfusion calorimetry as the sample was ball-milled. The data showed that the most particle size reduction occurred initially (d(0.5) dropping from 12.83+/-0.4 to 4.2+/-0.4 within 5 min). During this time period, no detectable amorphous content was observed. Between 5 and 15 min milling time the particle size distribution remained relatively constant but the amorphous content increased non-linearly with time. After 20 min milling time the particle size increased slightly. The data suggest that particle size reduction occurs initially upon application of a force to the crystal. Once maximum particle size reduction has occurred the crystal absorbs the force being applied and the crystal lattice becomes disordered. After extended milling the conditions in the ball mill (heat and/or humidity) may cause crystallisation of some of the amorphous material resulting in particle-particle fusion. It would appear that the ball-milling process could be optimised to achieve the desired particle size distribution but without any loss of crystalline structure.

  12. Horizontal gaze palsy with progressive scoliosis – A case report

    Directory of Open Access Journals (Sweden)

    P Shalini

    2017-01-01

    Full Text Available Horizontal gaze palsy with progressive scoliosis (HGPPS is a rare congenital disorder characterized by absence of conjugate horizontal eye movements and accompanied by progressive scoliosis developing in childhood and adolescence. It occurs due to mutation in ROBO 3 gene/chromosome 11q23-q25. We report a case of a 60-year-old lady who presented with complaints of defective vision in both eyes. On examination, she had scoliosis with restricted abduction and adduction in both eyes with intact elevation and depression. Magnetic resonance imaging of the brain and orbit showed brainstem hypoplasia with absence of facial colliculi, presence of a deep midline pontine cleft (split pons sign, and a butterfly configuration of the medulla, which are the radiological findings seen in this disorder.

  13. Mobile gaze-based screen interaction in 3D environments

    DEFF Research Database (Denmark)

    Mardanbeigi, Diako; Witzner Hansen, Dan

    2011-01-01

    Head-mounted eye trackers can be used for mobile interaction as well as gaze estimation purposes. This paper presents a method that enables the user to interact with any planar digital display in a 3D environment using a head-mounted eye tracker. An effective method for identifying the screens...... in the field of view of the user is also presented which can be applied in a general scenario in which multiple users can interact with multiple screens. A particular application of using this technique is implemented in a home environment with two big screens and a mobile phone. In this application a user...... was able to interact with these screens using a wireless head-mounted eye tracker....

  14. Gaze inspired subtitle position evaluation for MOOCs videos

    Science.gov (United States)

    Chen, Hongli; Yan, Mengzhen; Liu, Sijiang; Jiang, Bo

    2017-06-01

    Online educational resources, such as MOOCs, is becoming increasingly popular, especially in higher education field. One most important media type for MOOCs is course video. Besides traditional bottom-position subtitle accompany to the videos, in recent years, researchers try to develop more advanced algorithms to generate speaker-following style subtitles. However, the effectiveness of such subtitle is still unclear. In this paper, we investigate the relationship between subtitle position and the learning effect after watching the video on tablet devices. Inspired with image based human eye tracking technique, this work combines the objective gaze estimation statistics with subjective user study to achieve a convincing conclusion - speaker-following subtitles are more suitable for online educational videos.

  15. Backward-gazing method for measuring solar concentrators shape errors.

    Science.gov (United States)

    Coquand, Mathieu; Henault, François; Caliot, Cyril

    2017-03-01

    This paper describes a backward-gazing method for measuring the optomechanical errors of solar concentrating surfaces. It makes use of four cameras placed near the solar receiver and simultaneously recording images of the sun reflected by the optical surfaces. Simple data processing then allows reconstructing the slope and shape errors of the surfaces. The originality of the method is enforced by the use of generalized quad-cell formulas and approximate mathematical relations between the slope errors of the mirrors and their reflected wavefront in the case of sun-tracking heliostats at high-incidence angles. Numerical simulations demonstrate that the measurement accuracy is compliant with standard requirements of solar concentrating optics in the presence of noise or calibration errors. The method is suited to fine characterization of the optical and mechanical errors of heliostats and their facets, or to provide better control for real-time sun tracking.

  16. A Framework for Controlling Wheelchair Motion by using Gaze Information

    Directory of Open Access Journals (Sweden)

    Mohd Razali Tomari

    2014-01-01

    Full Text Available Users with severe motor ability are unable to control their wheelchair using standard joystick and hence an alternative control input is preferred. In this paper a method on how to enable the severe impairment user to control a wheelchair via gaze information is proposed. Since when using such an input, the navigation burden for the user is significantly increased, an assistive navigation platform is also proposed to reduce the user burden. Initially, user information is inferred using a camera and a bite-like switch. Then information from the environment is obtained using combination of laser and Kinect sensors. Eventually, both information from the environment and the user is analyzed to decide the final control operation that according to the user intention and safe from collision. Experimental results demonstrate the feasibility of the proposed approach.

  17. Cheap and Easy PIN Entering Using Eye Gaze

    Directory of Open Access Journals (Sweden)

    Kasprowski Pawel

    2014-03-01

    Full Text Available PINs are one of the most popular methods to perform simple and fast user authentication. PIN stands for Personal Identification Number, which may have any number of digits or even letters. Nevertheless, 4-digit PIN is the most common and is used for instance in ATMs or cellular phones. The main advantage of the PIN is that it is easy to remember and fast to enter. There are, however, some drawbacks. One of them - addressed in this paper - is a possibility to steal PIN by a technique called `shoulder surfing'. To avoid such problems a novel method of the PIN entering was proposed. Instead of using a numerical keyboard, the PIN may be entered by eye gazes, which is a hands-free, easy and robust technique. References:

  18. LOW COMPRESSION TENNIS BALLS AND SKILL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    John Hammond

    2006-12-01

    Full Text Available Coaching aims to improve player performance and coaches have a number of coaching methods and strategies they use to enhance this process. If new methods and ideas can be determined to improve player performance they will change coaching practices and processes. This study investigated the effects of using low compression balls (LCBs during coaching sessions with beginning tennis players. In order to assess the effectiveness of LCBs on skill learning the study employed a quasi-experimental design supported by qualitative and descriptive data. Beginner tennis players took part in coaching sessions, one group using the LCBs while the other group used standard tennis balls. Both groups were administered a skills at the beginning of a series of coaching sessions and again at the end. A statistical investigation of the difference between pre and post-test results was carried out to determine the effect of LCBs on skill learning. Additional qualitative data was obtained through interviews, video capture and the use of performance analysis of typical coaching sessions for each group. The skill test results indicated no difference in skill learning when comparing beginners using the LCBs to those using the standard balls. Coaches reported that the LCBs appeared to have a positive effect on technique development, including aspects of technique that are related to improving power of the shot. Additional benefits were that rallies went on longer and more opportunity for positive reinforcement. In order to provide a more conclusive answer to the effects of LCBs on skill learning and technique development recommendations for future research were established including a more controlled experimental environment and larger sample sizes across a longer period of time

  19. Interpolating sliding mode observer for a ball and beam system

    Science.gov (United States)

    Luai Hammadih, Mohammad; Hosani, Khalifa Al; Boiko, Igor

    2016-09-01

    A principle of interpolating sliding mode observer is introduced in this paper. The observer incorporates multiple linear observers through interpolation of multiple estimates, which is treated as a type of adaptation. The principle is then applied to the ball and beam system for observation of the slope of the beam from the measurement of the ball position. The linearised model of the ball and beam system using multiple linearisation points is developed. The observer dynamics implemented in Matlab/Simulink Real Time Workshop environment. Experiments conducted on the ball and beam experimental setup demonstrate excellent performance of the designed novel interpolating (adaptive) observer.

  20. [Diagnosis and treatment of fungal ball rhino-sinusitis].

    Science.gov (United States)

    Nie, Jun; Liu, Fenfang; Zhang, Hanwu; Li, Li

    2013-07-01

    To explore the diagnosis and treatment of the fungal ball rhino-sinusitis. The clinical data of 128 cases with the fungal ball rhino-sinusitis in our hospital between September 2005 and January 2012 were retrospectively analyzed. All patients were accepted nasal endoscopic surgery and followed up after surgery. The diagnosis were confirmed by postoperative pathological examination. The sinus of all patients epithelialized after the surgery from fourth to ninth weeks, one case recurred eight months later. Sinus CT scan and nasal endoscopy were very important to the diagnosis of the fungal ball rhino-sinusitis, and nasal endoscopic surgery is the most important treatment method to fungal ball rhino-sinusitis.

  1. CFD Analysis of Swing of Cricket Ball and Trajectory Prediction

    Science.gov (United States)

    G, Jithin; Tom, Josin; Ruishikesh, Kamat; Jose, Jyothish; Kumar, Sanjay

    2013-11-01

    This work aims to understand the aerodynamics associated with the flight and swing of a cricket ball and predict its flight trajectory over the course of the game: at start (smooth ball) and as the game progresses (rough ball). Asymmetric airflow over the ball due to seam orientation and surface roughness can cause flight deviation (swing). The values of Drag, Lift and Side forces which are crucial for determining the trajectory of the ball were found with the help of FLUENT using the standard K- ɛ model. Analysis was done to study how the ball velocity, spin imparted to be ball and the tilt of the seam affects the movement of the ball through air. The governing force balance equations in 3 dimensions in combination a MATLAB code which used Heun's method was used for obtaining the trajectory of the ball. The conditions for the conventional swing and reverse swing to occur were deduced from the analysis and found to be in alignment with the real life situation. Critical seam angle for maximum swing and transition speed for normal to reverse swing were found out. The obtained trajectories were compared to real life hawk eye trajectories for validation. The analysis results were in good agreement with the real life situation.

  2. The impact of coping style on gaze duration.

    Directory of Open Access Journals (Sweden)

    Tim Klucken

    Full Text Available The understanding of individual differences in response to threat (e.g., attentional bias is important to better understand the development of anxiety disorders. Previous studies revealed only a small attentional bias in high-anxious (HA subjects. One explanation for this finding may be the assumption that all HA-subjects show a constant attentional bias. Current models distinguish HA-subjects depending on their level of tolerance for uncertainty and for arousal. These models assume that only HA-subjects with intolerance for uncertainty but tolerance for arousal ("sensitizers" show an attentional bias, compared to HA-subjects with intolerance for uncertainty and intolerance for arousal ("fluctuating subjects". Further, it is assumed that repressors (defined as intolerance for arousal but tolerance for uncertainty would react with avoidance behavior when confronted with threatening stimuli. The present study investigated the influence of coping styles on attentional bias. After an extensive recruiting phase, 36 subjects were classified into three groups (sensitizers, fluctuating, and repressors. All subjects were exposed to presentations of happy and threatening faces, while recording gaze durations with an eye-tracker. The results showed that only sensitizer showed an attentional bias: they gazed longer at the threatening face rather than at the happy face during the first 500 ms. The results support the findings of the relationship between anxiety and attention and extend these by showing variations according to coping styles. The differentiation of subjects according to a multifaceted coping style allows a better prediction of the attentional bias and contributes to an insight into the complex interplay of personality, coping, and behavior.

  3. The impact of coping style on gaze duration.

    Science.gov (United States)

    Klucken, Tim; Brouwer, Anne-Marie; Chatziastros, Astros; Kagerer, Sabine; Netter, Petra; Hennig, Juergen

    2010-11-15

    The understanding of individual differences in response to threat (e.g., attentional bias) is important to better understand the development of anxiety disorders. Previous studies revealed only a small attentional bias in high-anxious (HA) subjects. One explanation for this finding may be the assumption that all HA-subjects show a constant attentional bias. Current models distinguish HA-subjects depending on their level of tolerance for uncertainty and for arousal. These models assume that only HA-subjects with intolerance for uncertainty but tolerance for arousal ("sensitizers") show an attentional bias, compared to HA-subjects with intolerance for uncertainty and intolerance for arousal ("fluctuating subjects"). Further, it is assumed that repressors (defined as intolerance for arousal but tolerance for uncertainty) would react with avoidance behavior when confronted with threatening stimuli. The present study investigated the influence of coping styles on attentional bias. After an extensive recruiting phase, 36 subjects were classified into three groups (sensitizers, fluctuating, and repressors). All subjects were exposed to presentations of happy and threatening faces, while recording gaze durations with an eye-tracker. The results showed that only sensitizer showed an attentional bias: they gazed longer at the threatening face rather than at the happy face during the first 500 ms. The results support the findings of the relationship between anxiety and attention and extend these by showing variations according to coping styles. The differentiation of subjects according to a multifaceted coping style allows a better prediction of the attentional bias and contributes to an insight into the complex interplay of personality, coping, and behavior.

  4. Structural evolution of ball-milled permalloy

    Energy Technology Data Exchange (ETDEWEB)

    Brzozka, K., E-mail: kbrzozka@poczta.f [Technical University, Department of Physics (Poland); Oleksakova, D.; Kollar, P. [P.J. Safarik University, Department of Condensed Matter Physics, Institute of Physics, Faculty of Science (Slovakia); Szumiata, T.; Gorka, B.; Gawronski, M. [Technical University, Department of Physics (Poland)

    2006-02-15

    Two series of Fe{sub 19.8}Ni{sub 80.2} samples obtained by ball milling and differing in the form of starting material were investigated by Moessbauer spectroscopy. In the case of milled elemental powder, strong structural evolution was stated: both {alpha} and {gamma} phases arise and a small amount of pure iron is present as well. The annealing of as-milled powder at 490{sup o}C causes faster forming of {gamma}-(Ni-Fe) phase. Only slight changes in atomic order were stated in the series of milled polycrystalline ribbon.

  5. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  6. Capillary floating and the billiard ball problem

    CERN Document Server

    Gutkin, Eugene

    2010-01-01

    We establish a connection between capillary floating in neutral equilibrium and the billiard ball problem. This allows us to reduce the question of floating in neutral equilibrium at any orientation with a prescribed contact angle for infinite homogeneous cylinders to a question about billiard caustics for their orthogonal cross-sections. We solve the billiard problem. As an application, we characterize the possible contact angles and exhibit an infinite family of real analytic non-round cylinders that float in neutral equilibrium at any orientation with constant contact angles.

  7. Observation of Lightning Ball (Ball Lightning): A new phenomenological description of the phenomenon

    CERN Document Server

    Tar, Domokos

    2009-01-01

    The author (physicist)has observed the very strange,beautiful and frightening Lightning Ball (LB). He has never forgotten this phenomenon. During his working life he could not devote himself to the problem of LB-formation.Only two years ago as he has been reading different unbelievable models of LB-formation, he decided to work on this problem. By studying the literature and the crucial points of his observation the author succeeded in creating a completely new model of Lightning Ball(LB) and Ball Lightning(BL)-formation based on the symmetry breaking of the hydrodynamic vortex ring.This agrees fully with the observation and overcomes the shortcomings of current models of LB formation. This model provides answers to the questions: Why are LBs so rarely observed,why do BLs in rare cases have such a high energy and how can we generate LB in the laboratory? Moreover the author differentiates between LB and BL, the latter having a high energy and occuring in 5 % of the observations. Keywords: ball lightning, hydr...

  8. The information for catching fly balls : Judging and intercepting virtual balls in a CAVE

    NARCIS (Netherlands)

    Zaal, FTJM; Michaels, CF

    2003-01-01

    Visually guided action implies the existence of information as well as a control law relating that information to movement. For ball catching, the Chapman Strategy-keeping constant the rate of change of the tangent of the elevation angle (d(tan(alpha))/dt)-leads a catcher to the right location at th

  9. Specificity of Age-Related Differences in Eye-Gaze Following: Evidence From Social and Nonsocial Stimuli.

    Science.gov (United States)

    Slessor, Gillian; Venturini, Cristina; Bonny, Emily J; Insch, Pauline M; Rokaszewicz, Anna; Finnerty, Ailbhe N

    2016-01-01

    Eye-gaze following is a fundamental social skill, facilitating communication. The present series of studies explored adult age-related differences in this key social-cognitive ability. In Study 1 younger and older adult participants completed a cueing task in which eye-gaze cues were predictive or non-predictive of target location. Another eye-gaze cueing task, assessing the influence of congruent and incongruent eye-gaze cues relative to trials which provided no cue to target location, was administered in Study 2. Finally, in Study 3 the eye-gaze cue was replaced by an arrow. In Study 1 older adults showed less evidence of gaze following than younger participants when required to strategically follow predictive eye-gaze cues and when making automatic shifts of attention to non-predictive eye-gaze cues. Findings from Study 2 suggested that, unlike younger adults, older participants showed no facilitation effect and thus did not follow congruent eye-gaze cues. They also had significantly weaker attentional costs than their younger counterparts. These age-related differences were not found in the non-social arrow cueing task. Taken together these findings suggest older adults do not use eye-gaze cues to engage in joint attention, and have specific social difficulties decoding critical information from the eye region. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Gaze transfer in remote cooperation: is it always helpful to see what your partner is attending to?

    Science.gov (United States)

    Müller, Romy; Helmert, Jens R; Pannasch, Sebastian; Velichkovsky, Boris M

    2013-01-01

    Establishing common ground in remote cooperation is challenging because nonverbal means of ambiguity resolution are limited. In such settings, information about a partner's gaze can support cooperative performance, but it is not yet clear whether and to what extent the abundance of information reflected in gaze comes at a cost. Specifically, in tasks that mainly rely on spatial referencing, gaze transfer might be distracting and leave the partner uncertain about the meaning of the gaze cursor. To examine this question, we let pairs of participants perform a joint puzzle task. One partner knew the solution and instructed the other partner's actions by (1) gaze, (2) speech, (3) gaze and speech, or (4) mouse and speech. Based on these instructions, the acting partner moved the pieces under conditions of high or low autonomy. Performance was better when using either gaze or mouse transfer compared to speech alone. However, in contrast to the mouse, gaze transfer induced uncertainty, evidenced in delayed responses to the cursor. Also, participants tried to resolve ambiguities by engaging in more verbal effort, formulating more explicit object descriptions and fewer deictic references. Thus, gaze transfer seems to increase uncertainty and ambiguity, thereby complicating grounding in this spatial referencing task. The results highlight the importance of closely examining task characteristics when considering gaze transfer as a means of support.

  11. [Judgment of gaze direction related to social anxiety: facial expressions and interpretation biases].

    Science.gov (United States)

    Ishikawa, Kenta; Okamura, Yoko; Okubo, Matia

    2012-08-01

    The present study investigated the effects of social anxiety on judgments about gaze direction. The participants (N = 123) were divided into two groups on the basis of social anxiety scores (social anxiety and control group). Participants who scored high on a social anxiety scale judged the direction of slightly averted gaze to be straight more often for angry faces than for neutral faces. This pattern was reversed for participants in control group. An angry face looking straight at a person may be seen as an overt threat. People suffering from social anxiety tend to interpret ambiguous situations as negative or threatening. This negativity bias may contribute to the increased judgments of straight-gaze responses for angry faces with slightly averted gazes.

  12. Does gaze direction modulate facial expression processing in children with autism spectrum disorder?

    Science.gov (United States)

    Akechi, Hironori; Senju, Atsushi; Kikuchi, Yukiko; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

    2009-01-01

    Two experiments investigated whether children with autism spectrum disorder (ASD) integrate relevant communicative signals, such as gaze direction, when decoding a facial expression. In Experiment 1, typically developing children (9-14 years old; n = 14) were faster at detecting a facial expression accompanying a gaze direction with a congruent motivational tendency (i.e., an avoidant facial expression with averted eye gaze) than those with an incongruent motivational tendency. Children with ASD (9-14 years old; n = 14) were not affected by the gaze direction of facial stimuli. This finding was replicated in Experiment 2, which presented only the eye region of the face to typically developing children (n = 10) and children with ASD (n = 10). These results demonstrated that children with ASD do not encode and/or integrate multiple communicative signals based on their affective or motivational tendency.

  13. Collicular Microstimulation During Passive Rotation Does Not Generate Fixed Gaze Shifts

    National Research Council Canada - National Science Library

    A. D. Van Beuzekom; J.A.M. Van Gisbergen

    2002-01-01

    We investigated whether saccades evoked by electrical stimulation (E-saccades) in the superior colliculus can compensate for passive sinusoidal head rotation in yaw so as to keep the rapid gaze shift constant...

  14. The influence of emotional facial expressions on gaze-following in grouped and solitary pedestrians.

    Science.gov (United States)

    Gallup, Andrew C; Chong, Andrew; Kacelnik, Alex; Krebs, John R; Couzin, Iain D

    2014-07-23

    The mechanisms contributing to collective attention in humans remain unclear. Research indicates that pedestrians utilise the gaze direction of others nearby to acquire environmentally relevant information, but it is not known which, if any, additional social cues influence this transmission. Extending upon previous field studies, we investigated whether gaze cues paired with emotional facial expressions (neutral, happy, suspicious and fearsome) of an oncoming walking confederate modulate gaze-following by pedestrians moving in a natural corridor. We found that pedestrians walking alone were not sensitive to this manipulation, while individuals traveling together in groups did reliably alter their response in relation to emotional cues. In particular, members of a collective were more likely to follow gaze cues indicative of a potential threat (i.e., suspicious or fearful facial expression). This modulation of visual attention dependent on whether pedestrians are in social aggregates may be important to drive adaptive exploitation of social information, and particularly emotional stimuli within natural contexts.

  15. Gaze stabilization reflexes in the mouse: New tools to study vision and sensorimotor

    NARCIS (Netherlands)

    B. van Alphen (Bart)

    2010-01-01

    markdownabstract__abstract__ Gaze stabilization reflexes are a popular model system in neuroscience for connecting neurophysiology and behavior as well as studying the neural correlates of behavioral plasticity. These compensatory eye movements are one of the simplest motor behaviors,

  16. Gaze angle: a possible mechanism of visual stress in virtual reality headsets.

    Science.gov (United States)

    Mon-Williams, M; Plooy, A; Burgess-Limerick, R; Wann, J

    1998-03-01

    It is known that some Virtual Reality (VR) head-mounted displays (HMDs) can cause temporary deficits in binocular vision. On the other hand, the precise mechanism by which visual stress occurs is unclear. This paper is concerned with a potential source of visual stress that has not been previously considered with regard to VR systems: inappropriate vertical gaze angle. As vertical gaze angle is raised or lowered the 'effort' required of the binocular system also changes. The extent to which changes in vertical gaze angle alter the demands placed upon the vergence eye movement system was explored. The results suggested that visual stress may depend, in part, on vertical gaze angle. The proximity of the display screens within an HMD means that a VR headset should be in the correct vertical location for any individual user. This factor may explain some previous empirical results and has important implications for headset design. Fortuitously, a reasonably simple solution exists.

  17. Children with ASD Can Use Gaze in Support of Word Recognition and Learning

    Science.gov (United States)

    McGregor, Karla K.; Rost, Gwyneth; Arenas, Rick; Farris-Trimble, Ashley; Stiles, Derek

    2013-01-01

    Background: Many children with autism spectrum disorders (ASD) struggle to understand familiar words and learn unfamiliar words. We explored the extent to which these problems reflect deficient use of probabilistic gaze in the

  18. Beggars, Black Bears, and Butterflies: The Scientific Gaze and Ink Painting in Modern China

    National Research Council Canada - National Science Library

    Lisa Claypool

    2015-01-01

    ...” scientific gaze with their idiosyncratically trained vision as artists, they created pictures that encouraged their viewers to cross the boundaries and binaries that would come to define the discourse about guohua, or “national painting...

  19. Memory in random bouncing ball dynamics

    Science.gov (United States)

    Zouabi, C.; Scheibert, J.; Perret-Liaudet, J.

    2016-09-01

    The bouncing of an inelastic ball on a vibrating plate is a popular model used in various fields, from granular gases to nanometer-sized mechanical contacts. For random plate motion, so far, the model has been studied using Poincaré maps in which the excitation by the plate at successive bounces is assumed to be a discrete Markovian (memoryless) process. Here, we investigate numerically the behaviour of the model for continuous random excitations with tunable correlation time. We show that the system dynamics are controlled by the ratio of the Markovian mean flight time of the ball and the mean time between successive peaks in the motion of the exciting plate. When this ratio, which depends on the bandwidth of the excitation signal, exceeds a certain value, the Markovian approach is appropriate; below, memory of preceding excitations arises, leading to a significant decrease of the jump duration; at the smallest values of the ratio, chattering occurs. Overall, our results open the way for uses of the model in the low-excitation regime, which is still poorly understood.

  20. Crises in a dissipative bouncing ball model

    Energy Technology Data Exchange (ETDEWEB)

    Livorati, André L.P., E-mail: livorati@usp.br [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Caldas, Iberê L. [Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Dettmann, Carl P. [School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Leonel, Edson D. [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil)

    2015-11-06

    Highlights: • We studied a dissipative bouncing ball dynamics. • A two-dimensional nonlinear mapping describes the dynamics. • Crises between attractors and its manifolds were characterized. • A new physical crisis between vibrating platform and an attractor was characterized. • The existence of a ‘robust’ chaotic attractor was set. - Abstract: The dynamics of a bouncing ball model under the influence of dissipation is investigated by using a two-dimensional nonlinear mapping. When high dissipation is considered, the dynamics evolves to different attractors. The evolution of the basins of the attracting fixed points is characterized, as we vary the control parameters. Crises between the attractors and their boundaries are observed. We found that the multiple attractors are intertwined, and when the boundary crisis between their stable and unstable manifolds occurs, it creates a successive mechanism of destruction for all attractors originated by the sinks. Also, a physical impact crisis is described, an important mechanism in the reduction of the number of attractors.