Science.gov

Sample records for apsidal motion rate

  1. Apsidal motion in eclipsing binary GG Orionis

    NASA Astrophysics Data System (ADS)

    Yilan, E.; Bulut, I.

    2016-03-01

    The study of apsidal motion in binary stars with eccentric orbit is well known as an important source of information for the stellar internal structure as well as the possibility of verification of general relativity. In this study, the apsidal motion of the eccentric eclipsing binary GG Ori (P = 6.631 days, e = 0.22) has been analyzed using the times of minimum light taken from the literature and databases and the elements of apsidal motion have been computed. The method described by Giménez and García-Pelayo (1983) has been used for the apsidal motion analysis.

  2. APSIDAL MOTION IN ECCENTRIC ECLIPSING BINARY WW CAMELOPARDALIS

    SciTech Connect

    Wolf, M.; Kotkova, L.; Kocian, R.; Dreveny, R.; Hanzl, D.

    2010-03-15

    WW Camelopardalis is a relatively bright eclipsing binary system with a slightly eccentric orbit. A dozen of its new eclipse times were measured as part of our long-term observational project of eccentric eclipsing binaries. Based on a new solution of the current O - C diagram, we found for the first time an apsidal motion in good agreement with theory. Its period is about 370 {+-} 50 years. The determined internal structure constant is close to the theoretically expected value. The relativistic effect is significant, being about 13% of the total apsidal motion rate.

  3. Generalized Solution for Binary Star Ephemerides and Apsidal Motion

    NASA Astrophysics Data System (ADS)

    van Hamme, W. V.; Wilson, R. E.

    1998-12-01

    We demonstrate generalized determination of apsidal motion rates (domega /dt's), orbital periods (P's), and period changes (dP/dt's) in binary stars. Our method can use eclipses but is not restricted to eclipse data. A general binary star program solves for domega /dt and/or ephemeris parameters together with other binary star quantities, and combines radial velocities and light curves within a coherent analysis. We can use data that may have large timewise gaps and may be far less than optimally distributed over time. The method is particularly useful when the apsidal period is long and eclipse timings cover only a small part of the cycle. We show apsidal motion results for AS Cam and find a domega /dt of 18.20+/-0.66 arcdeg /100;yr. This result compares to a domega /dt of 13.2+/-1.8 arcdeg /100;yr obtained from a traditional weighted least squares fit to almost 100 years of times of minima, which is 3.3 times smaller than predicted by theory. Other published estimates for the apsidal motion rate are 15.0+/-5.3 arcdeg /100;yr by Maloney, Guinan & Mukherjee (1991, AJ, 102, 256), and 18.3+/-2.6 arcdeg /100;yr by Wolf, \\u{S}arounova & Diethelm (1996, A&AS, 116, 463). Apsidal motion determined from times of minima depends on the value of the eccentricity e. Our result is for e = 0.1633, obtained from the light and velocity solution. The new domega /dt from the general analysis is 2.4 times smaller than theory, with a standard error 3 times smaller than in the traditional method. Our apsidal period of 1978+/-71 year is based on only 30 years of light and velocity curves, or 1.5% of the cycle. The method also works well in measuring period changes in long period giant binaries (such as symbiotics), considering that these stars are typically observed in fragments and that very few show eclipses that are useful as timing ticks. Our dP/dt results for the symbiotic binary AG Peg have implications for its future evolution. Natural extensions of the idea can include other

  4. Apsidal motion in the massive binary HD 152218

    NASA Astrophysics Data System (ADS)

    Rauw, G.; Rosu, S.; Noels, A.; Mahy, L.; Schmitt, J. H. M. M.; Godart, M.; Dupret, M.-A.; Gosset, E.

    2016-10-01

    Massive binary systems are important laboratories in which to probe the properties of massive stars and stellar physics in general. In this context, we analysed optical spectroscopy and photometry of the eccentric short-period early-type binary HD 152218 in the young open cluster NGC 6231. We reconstructed the spectra of the individual stars using a disentangling code. The individual spectra were then compared with synthetic spectra obtained with the CMFGEN model atmosphere code. We furthermore analysed the light curve of the binary and used it to constrain the orbital inclination and to derive absolute masses of (19.8 ± 1.5) and (15.0 ± 1.1) M⊙. Combining radial velocity measurements from over 60 yr, we show that the system displays apsidal motion at a rate of (2.04+ .23-.24)° yr-1. Solving the Clairaut-Radau equation, we used stellar evolution models, obtained with the CLES code, to compute the internal structure constants and to evaluate the theoretically predicted rate of apsidal motion as a function of stellar age and primary mass. In this way, we determine an age of 5.8 ± 0.6 Myr for HD 152218, which is towards the higher end of, but compatible with, the range of ages of the massive star population of NGC 6231 as determined from isochrone fitting.

  5. Apsidal Motion Study of Close Binary System CW Cephei

    NASA Astrophysics Data System (ADS)

    Han, Wonyong; Jeong, Min-Ji; Yoon, Joh-Na; Kim, Hyoun-Woo; Kim, Yonggii; Kim, Chun-Hwey

    2015-12-01

    New observations for the times of minimum lights of a well-known apsidal motion star CW Cephei were made using a 0.6 m wide field telescope at Jincheon station of Chungbuk National University Observatory, Korea during the 2015 observational season. We determined new times of minimum lights from these observations and analyzed O-C diagrams together with collected times of minima to study both the apsidal motion and the Light Time Effect (LTE) suggested in the system. The new periods of the apsidal motion and the LTE were calculated as 46.6 and 39.3 years, respectively, which were similar but improved accuracy than earlier ones investigated by Han et al. (2002), Erdem et al. (2004) and Wolf et al. (2006).

  6. The unique eclipsing binary system V541 Cygni with relativistic apsidal motion

    NASA Astrophysics Data System (ADS)

    Khaliullin, K. F.

    1985-12-01

    The first photoelectric light curve has been obtained for the binary star V541 Cygni (B8.5 V+B8.7 V, P = 15d.34) discovered by Kulikowski (1948). The light curve exhibits extremely narrow and deep minima of almost equal depth. Photometric elements are determined. Very small relative radii, orbital inclination close to π/2, high eccentricity (e = 0.474), and favorable orientation of the line of apsides with respect to an observer, as well as close similarity of the components, render the V541 Cyg system unique among eclipsing binaries. The apsidal motion in this system has been detected. The observed rotation rate of the line of apsides, ωobs = 0°.090±0°.013 yr-1, agrees within the errors with the prediction by general relativity.

  7. Apsidal motion of two eclipsing binaries: V796 Cyg and V2783 Ori

    NASA Astrophysics Data System (ADS)

    Bulut, A.; Bulut, I.; ćiçek, C.; Erdem, A.

    2017-02-01

    In this study, the orbital period variations of two eclipsing binary systems showing apsidal motion were studied. Their O - C diagrams were analysed using all reliable eclipse timings and the elements of apsidal motion of two systems were improved. We found periods of apsidal motion of V796 Cyg and V2783 Ori to be 32.7 ± 0.2 years and 415 ± 50 years, respectively.

  8. Orbital evolution and search for eccentricity and apsidal motion in the eclipsing HMXB 4U 1700-37

    NASA Astrophysics Data System (ADS)

    Islam, Nazma; Paul, Biswajit

    2016-09-01

    In the absence of detectable pulsations in the eclipsing high-mass X-ray binary 4U 1700-37, the orbital period decay is necessarily determined from the eclipse timing measurements. We have used the earlier reported mid-eclipse time measurements of 4U 1700-37 together with the new measurements from long-term light curves obtained with the all sky monitors RXTE-ASM, Swift-BAT and MAXI-GSC, as well as observations with RXTE-PCA, to measure the long-term orbital evolution of the binary. The orbital period decay rate of the system is estimated to be {dot{P}}/P = -(4.7 ± 1.9) × 10^{-7} yr-1, smaller compared to its previous estimates. We have also used the mid-eclipse times and the eclipse duration measurements obtained from 10-years-long X-ray light curve with Swift-BAT to separately put constraints on the eccentricity of the binary system and attempted to measure any apsidal motion. For an apsidal motion rate greater than 5 deg yr-1, the eccentricity is found to be less than 0.008, which limits our ability to determine the apsidal motion rate from the current data. We discuss the discrepancy of the current limit of eccentricity with the earlier reported values from radial velocity measurements of the companion star.

  9. APSIDAL MOTION AND A LIGHT CURVE SOLUTION FOR 13 LMC ECCENTRIC ECLIPSING BINARIES

    SciTech Connect

    Zasche, P.; Wolf, M.; Vraštil, J.; Pilarcik, L.

    2015-12-15

    New CCD observations for 13 eccentric eclipsing binaries from the Large Magellanic Cloud were carried out using the Danish 1.54 m telescope located at the La Silla Observatory in Chile. These systems were observed for their times of minimum and 56 new minima were obtained. These are needed for accurate determination of the apsidal motion. Besides that, in total 436 times of minimum were derived from the photometric databases OGLE and MACHO. The O – C diagrams of minimum timings for these B-type binaries were analyzed and the parameters of the apsidal motion were computed. The light curves of these systems were fitted using the program PHOEBE, giving the light curve parameters. We derived for the first time relatively short periods of the apsidal motion ranging from 21 to 107 years. The system OGLE-LMC-ECL-07902 was also analyzed using the spectra and radial velocities, resulting in masses of 6.8 and 4.4 M{sub ⊙} for the eclipsing components. For one system (OGLE-LMC-ECL-20112), the third-body hypothesis was also used to describe the residuals after subtraction of the apsidal motion, resulting in a period of about 22 years. For several systems an additional third light was also detected, which makes these systems suspect for triplicity.

  10. The apsidal motion of the eccentric eclipsing binary DI Herculis - An apparent discrepancy with general relativity

    NASA Technical Reports Server (NTRS)

    Guinan, E. F.; Maloney, F. P.

    1985-01-01

    The apsidal motion of the eccentric eclipsing binary DI Herculis (HD 175227) is determined from an analysis of the available observations and eclipse timings from 1959 to 1984. Least squares solutions to the primary and secondary minima extending over an 84-yr interval yielded a small advance of periastron omega dot of 0.65 deg/100 yr + or - 0.18/100 yr. The observed advance of the periastron is about one seventh of the theoretical value of 4.27 deg/100 yr that is expected from the combined relativistic and classical effects. The discrepancy is about -3.62 deg/100 yr, or a magnitude of about 20 sigma. Classical mechanisms which explain the discrepancy are discussed, together with the possibility that there may be problems with general relativity itself.

  11. Holding or Breaking with Ptolemy's Generalization: Considerations about the Motion of the Planetary Apsidal Lines in Medieval Islamic Astronomy.

    PubMed

    Mozaffari, S Mohammad

    2017-03-01

    Argument In the Almagest, Ptolemy finds that the apogee of Mercury moves progressively at a speed equal to his value for the rate of precession, namely one degree per century, in the tropical reference system of the ecliptic coordinates. He generalizes this to the other planets, so that the motions of the apogees of all five planets are assumed to be equal, while the solar apsidal line is taken to be fixed. In medieval Islamic astronomy, one change in this general proposition took place because of the discovery of the motion of the solar apogee in the ninth century, which gave rise to lengthy discussions on the speed of its motion. Initially Bīrūnī and later Ibn al-Zarqālluh assigned a proper motion to it, although at different rates. Nevertheless, appealing to the Ptolemaic generalization and interpreting it as a methodological axiom, the dominant idea became to extend it in order to include the motion of the solar apogee as well. Another change occurred after correctly making a distinction between the motion of the apogees and the rate of precession. Some Western Islamic astronomers generalized Ibn al-Zarqālluh's proper motion of the solar apogee to the apogees of the planets. Analogously, Ibn al-Shāṭir maintained that the motion of the apogees is faster than precession. Nevertheless, the Ptolemaic generalization in the case of the equality of the motions of the apogees remained untouchable, despite the notable development of planetary astronomy, in both theoretical and observational aspects, in the late Islamic period.

  12. V346 Centauri: Early-type eclipsing binary with apsidal motion and abrupt change of orbital period

    NASA Astrophysics Data System (ADS)

    Mayer, Pavel; Harmanec, Petr; Wolf, Marek; Nemravová, Jana; Prša, Andrej; Frémat, Yves; Zejda, Miloslav; Liška, Jiři; Juryšek, Jakub; Hoňková, Kateřina; Mašek, Martin

    2016-06-01

    New physical elements of the early B-type eclipsing binary V346 Cen are derived using the HARPS spectra downloaded from the ESO archive and also numerous photometric observations from various sources. A model of the observed times of primary and secondary minima that fits them best is a combination of the apsidal motion and an abrupt decrease in the orbital period from 6.^d322123 to 6.^d321843 (shortening by 24 s), which occurred somewhere around JD 2 439 000. Assumption of a secularly decreasing orbital period provides a significantly worse fit. Local times of minima and the final solution of the light curve were obtained with the program PHOEBE. Radial velocities of both binary components, free of line blending, were derived via 2D cross-correlation with a program built on the principles of the program TODCOR. The oxygen lines in the secondary spectra are weaker than those in the model spectra of solar chemical composition. Using the component spectra disentangled with the program KOREL, we find that both components rotate considerably faster than would correspond to the synchronization at periastron. The apside rotation known from earlier studies is confirmed and compared to the theoretical value. Based on observations made with the ESO telescopes at the La Silla Paranal Observatory under programmes ID 083.D-0040(A), 085.C-0614(A), and 178.D-0361(B).Tables A.2-A.6 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A129

  13. Probing the Masses of the PSR JO621+1002 Binary System Through Relativistic Apsidal Motion

    NASA Technical Reports Server (NTRS)

    Spaver, Eric M.; Nice, David J.; Arzoumanian, Zaven; Camilo, Fernando; Lyne, Andrew G.; Stairs, Ingrid H.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    Orbital, spin and astrometric parameters of the millisecond pulsar PSR J0621+1002 have been determined through six years of timing observations at three radio telescopes. The chief result is a measurement of the rate of periastron advance, omega=0 deg.0116 +/-0 deg.0008/yr. Interpreted as a general relativistic effect, this implies the sum of the pulsar mass, m(1), and the companion mass, m(2), to be M=m(1)+m(2)= 2.81 +/-0.30 solar mass. The Keplerian parameters rule out certain combinations of m(1) and m(2), as does the non-detection of Shapiro delay in the pulse arrival times. These constraints, together with the assumption that the companion is a white dwarf, lead to the maximum likelihood values m(1)=1.69((sup +0.30)(sub -0.30)) solar mass and m(2)=0.98((sup +0.32)(sub -0.12) solar mass (68% confidence). The other major finding is that the pulsar experiences dramatic variability in its dispersion measure (DM), with gradients as steep as 0.013 pc/cu cm/yr. A structure function analysis of the DM variations uncovers spatial fluctuations in the interstellar electron density that cannot be fit to a single power law, unlike the Kolmogorov turbulent spectrum that has been seen in the direction of other pulsars. Other results from the timing analysis include the first measurements of the pulsar's proper motion, mu=3.5+/-0.3 mas/yr, and of its spin-down rate, dP/dt=4.7 x 10(exp -20), which, when corrected for kinematic biases and combined with the pulse period, P=28.8 ms, gives a characteristic age of 1.1 x 10(exp 10) yr and a surface magnetic field strength of 1.2 x 10 (exp 9) G.

  14. The α CrB binary system: A new radial velocity curve, apsidal motion, and the alignment of rotation and orbit axes

    NASA Astrophysics Data System (ADS)

    Schmitt, J. H. M. M.; Schröder, K.-P.; Rauw, G.; Hempelmann, A.; Mittag, M.; González-Pérez, J. N.; Czesla, S.; Wolter, U.; Jack, D.

    2016-02-01

    We present a new radial velocity curve for the two components of the eclipsing spectroscopic binary α CrB. This binary consists of two main-sequence stars of types A and G in a 17.3599-day orbit, according to the data from our robotic TIGRE facility that is located in Guanajuato, Mexico. We used a high-resolution solar spectrum to determine the radial velocities of the weak secondary component by cross-correlation and wavelength referencing with telluric lines for the strongly rotationally broadened primary lines (v sin(i) = 138 km s-1) to obtain radial velocities with an accuracy of a few hundred m/s. We combined our new RV data with older measurements, dating back to 1908 in the case of the primary, to search for evidence of apsidal motion. We find an apsidal motion period between 6600 and 10 600 yr. This value is consistent with the available data for both the primary and secondary and is also consistent with the assumption that the system has aligned orbit and rotation axes.

  15. Short apsidal period of three eccentric eclipsing binaries discovered in the Large Magellanic Cloud

    SciTech Connect

    Hong, Kyeongsoo; Lee, Chung-Uk; Kim, Seung-Lee; Kang, Young-Woon

    2014-06-01

    We present new elements of apsidal motion in three eccentric eclipsing binaries located in the Large Magellanic Cloud. The apsidal motions of the systems were analyzed using both light curves and eclipse timings. The OGLE-III data obtained during the long period of 8 yr (2002-2009) allowed us to determine the apsidal motion period from their analyses. The existence of third light in all selected systems was investigated by light curve analysis. The O – C diagrams of EROS 1018, EROS 1041, and EROS 1054 were analyzed using the 30, 44, and 26 new times of minimum light, respectively, determined from full light curves constructed from EROS, MACHO, OGLE-II, OGLE-III, and our own observations. This enabled a detailed study of the apsidal motion in these systems for the first time. All of the systems have a significant apsidal motion below 100 yr. In particular, EROS 1018 shows a very fast apsidal period of 19.9 ± 2.2 yr in a detached system.

  16. Short Apsidal Period of Three Eccentric Eclipsing Binaries Discovered in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Hong, Kyeongsoo; Lee, Chung-Uk; Kim, Seung-Lee; Kang, Young-Woon

    2014-06-01

    We present new elements of apsidal motion in three eccentric eclipsing binaries located in the Large Magellanic Cloud. The apsidal motions of the systems were analyzed using both light curves and eclipse timings. The OGLE-III data obtained during the long period of 8 yr (2002-2009) allowed us to determine the apsidal motion period from their analyses. The existence of third light in all selected systems was investigated by light curve analysis. The O - C diagrams of EROS 1018, EROS 1041, and EROS 1054 were analyzed using the 30, 44, and 26 new times of minimum light, respectively, determined from full light curves constructed from EROS, MACHO, OGLE-II, OGLE-III, and our own observations. This enabled a detailed study of the apsidal motion in these systems for the first time. All of the systems have a significant apsidal motion below 100 yr. In particular, EROS 1018 shows a very fast apsidal period of 19.9 ± 2.2 yr in a detached system.

  17. The role of solar apsidal resonance in the evolution of geostationary transfer orbits

    NASA Astrophysics Data System (ADS)

    Wang, Yue; Gurfil, Pini

    2017-04-01

    Subjected to multiple perturbations and their complex interplay, the dynamical evolution of geostationary transfer orbits (GTOs) is sensitive to initial conditions and model parameters. As one of the most remarkable outcomes of multiple perturbations, the solar apsidal resonance, i.e., the 1:1 resonance between the solar orbital motion and the rotation of the orbital apsidal line caused by Earth's oblateness, is an important feature of the GTO evolution. It occurs when the semi-major axis is reduced by the atmospheric drag to the critical value, with which the rotation of the orbital apsidal line is commensurate with the solar orbital motion. In the present paper, we show that the solar apsidal resonance plays an important role in the evolution and decay of GTOs. To do so, we first explain the underlying dynamical mechanism of the solar apsidal resonance, which is the U-turn of the solar azimuth with respect to the orbital apsidal line and the resulting monotonic increase or decrease of the eccentricity. The resonance is then classified into three kinds, and their causes and effects are analyzed. Previous studies have regarded the solar apsidal resonance as a mechanism extending the orbital lifetime. However, we find that in most cases the GTO will re-enter Earth's atmosphere soon or only several years after the resonance, and so the solar apsidal resonance can be regarded as the prelude to the GTO final re-entry. Finally, the sensitivity of orbital dynamics is studied through numerical simulations. It is shown that the high sensitivity of the dynamics can be attributed to the resonance, which is difficult to predict or manage. With the initial state, it is possible to predict the orbit evolution of GTO only before the solar apsidal resonance. To predict the lifetime of GTO, new measurements on the orbit after the resonance are required.

  18. KIC 3749404: a heartbeat star with rapid apsidal advance indicative of a tertiary component

    NASA Astrophysics Data System (ADS)

    Hambleton, K.; Kurtz, D. W.; Prša, A.; Quinn, S. N.; Fuller, J.; Murphy, S. J.; Thompson, S. E.; Latham, D. W.; Shporer, A.

    2016-12-01

    Heartbeat stars are eccentric (e > 0.2) ellipsoidal variables whose light curves resemble a cardiogram. We present the observations and corresponding model of KIC 3749404, a highly eccentric (e = 0.66), short period (P = 20.3 d) heartbeat star with tidally induced pulsations. A binary star model was created using PHOEBE, which we modified to include tidally induced pulsations and Doppler boosting. The morphology of the photometric periastron variation (heartbeat) depends strongly on the eccentricity, inclination and argument of periastron. We show that the inclusion of tidally induced pulsations in the model significantly changes the parameter values, specifically the inclination and those parameters dependent on it. Furthermore, we determine the rate of apsidal advance by modelling the periastron variation at the beginning and end of the 4-yr Kepler data set and dividing by the elapsed time. We compare the model with the theoretical expectations for classical and general relativistic apsidal motion and find the observed rate to be two orders of magnitude greater than the theoretical rate. We find that the observed rate cannot be explained by tidally induced pulsations alone and consequently hypothesize the presence of a third body in the system.

  19. TIDALLY INDUCED APSIDAL PRECESSION IN DOUBLE WHITE DWARFS: A NEW MASS MEASUREMENT TOOL WITH LISA

    SciTech Connect

    Valsecchi, F.; Farr, W. M.; Willems, B.; Deloye, C. J.; Kalogera, V.

    2012-02-01

    Galactic interacting double white dwarfs (DWDs) are guaranteed gravitational wave (GW) sources for the Laser Interferometer Space Antenna GW detector, with more than 10{sup 4} binaries expected to be detected over the mission's lifetime. Part of this population is expected to be eccentric, and here we investigate the potential for constraining the white dwarf (WD) properties through apsidal precession in these binaries. We analyze the tidal, rotational, and general relativistic contributions to apsidal precession by using detailed He WD models, where the evolution of the star's interior is followed throughout the cooling phase. In agreement with previous studies of zero-temperature WDs, we find that apsidal precession in eccentric DWDs can lead to a detectable shift in the emitted GW signal when binaries with cool (old) components are considered. This shift increases significantly for hot (young) WDs. We find that apsidal motion in hot (cool) DWDs is dominated by tides at orbital frequencies above {approx}> 10{sup -4} Hz (10{sup -3} Hz). The analysis of apsidal precession in these sources while ignoring the tidal component would lead to an extreme bias in the mass determination, and could lead us to misidentify WDs as neutron stars or black holes. We use the detailed WD models to show that for older, cold WDs, there is a unique relationship that ties the radius and apsidal precession constant to the WD masses, therefore allowing tides to be used as a tool to constrain the source masses.

  20. Apsidal rotation in the eclipsing binary AG Persei

    NASA Technical Reports Server (NTRS)

    Koch, Robert H.; Woodward, Edith J.

    1987-01-01

    New three-filter light curves of AG Per are given. These yield times of minimum light in accord with the known rate of apsidal rotation but do not improve that rate. These light curves and all other published historical ones have been treated with the code EBOP and are shown to give largely consistent geometric and photometric parameters no matter which orientation of the orbit is displayed to the observer.

  1. Eccentricity Inferences in Multi-planet systems with Transit Timing: Degeneracies and Apsidal Alignment

    NASA Astrophysics Data System (ADS)

    Jontof-Hutter, Daniel; Van Laerhoven, Christa L.; Ford, Eric B.

    2016-05-01

    Hundreds of multi-transiting systems discovered by the Kepler mission show Transit Timing Variations (TTV). In cases where the TTVs are uniquely attributable to transiting planets, the TTVs enable precise measurements of planetary masses and orbital parameters. Of particular interest are the constraints on eccentricity vectors that can be inferred in systems of low-mass exoplanets.The TTVs in these systems are dominated by a signal caused by near-resonant mean motions. This causes the well-known near-degeneracy between planetary masses and orbital eccentricities. In addition, it causes a degeneracy between the eccentricities of interacting planet pairs.For many systems, the magnitude of individual eccentricities are weakly constrained, yet the data typically provide a tight constraint on the posterior joint distribution for the eccentricity vector components. This permits tight constraints on the relative eccentricity and degree of alignment of interacting planets.For a sample of two and three-planet systems with TTVs, we highlight the effects of these correlations. While the most eccentric orbital solutions for these systems show apsidal alignment, this is often due to the degeneracy that causes correlated constraints on the eccentricity vector components. We compare the likelihood of apsidal alignment for two choices of eccentricity prior: a wide prior using a Rayleigh distribution of scale length 0.1 and a narrower prior with scale length 0.02. In all cases the narrower prior decreased the fraction of samples that exhibited apsidal alignment. However, apsidal alignment persisted in the majority of cases with a narrower eccentricity prior. For a sample of our TTV solutions, we ran simulations of these systems over secular timescales, and decomposed their eccentricity eigenmodes over time, confirming that in most cases, the eccentricities were dominated by parallel eigenmodes which favor apsidal alignment.

  2. Dynamics of the Trans-Neptune Region: Apsidal Waves in the Kuiper Belt

    NASA Technical Reports Server (NTRS)

    Ward, William R.; Hahn, Joseph M.

    1998-01-01

    The role of apsidal density waves propagating in a primordial trans-Neptune disk (i.e., Kuiper belt) is investigated. It is shown that Neptune launches apsidal waves at its secular resonance near 40 AU that propagate radially outward, deeper into the particle disk. The wavelength of apsidal waves is considerably longer than waves that might be launched at Lindblad resonances, because the pattern speed, g(sub s), resulting from the apsis precession of Neptune is much slower than its mean motion, Omega(sub s). If the early Kuiper belt had a sufficient surface density, sigma, the disk's wave response to Neptune's secular perturbation would have spread the disturbing torque radially over a collective scale lambda(sub *) approx. = r(2(mu)(sub d)Omega/ absolute value of r dg/dr)(sup 1/2), where mu(sub d)equivalent pi(sigma)r(exp 2)/(1 solar mass) and Omega(r) and g(r) are respectively the mean motion and precession frequency of the disk particles. This results in considerably smaller eccentricities at resonance than had the disk particles been treated as noninteracting test particles. Consequently, particles are less apt to be excited into planet-crossing orbits, implying that the erosion timescales reported by earlier test-particle simulations of the Kuiper belt may be underestimated. It is also shown that the torque the disk exerts upon the planet (due to its gravitational attraction for the disk's spiral wave pattern) damps the planet's eccentricity and further inhibits the planet's ability to erode the disk. Key words: celestial mechanics, stellar dynamics - comets: general minor planets, asteroids

  3. Alternating and Sequential Motion Rates in Older Adults

    ERIC Educational Resources Information Center

    Pierce, John E.; Cotton, Susan; Perry, Alison

    2013-01-01

    Background: Alternating motion rate (AMR) and sequential motion rate (SMR) are tests of articulatory diadochokinesis that are widely used in the evaluation of motor speech. However, there are no quality normative data available for adults aged 65 years and older. Aims: There were two aims: (1) to obtain a representative, normative dataset of…

  4. Human heart rate variability relation is unchanged during motion sickness

    NASA Technical Reports Server (NTRS)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.

  5. Interactive-rate Motion Planning for Concentric Tube Robots.

    PubMed

    Torres, Luis G; Baykal, Cenk; Alterovitz, Ron

    2014-05-01

    Concentric tube robots may enable new, safer minimally invasive surgical procedures by moving along curved paths to reach difficult-to-reach sites in a patient's anatomy. Operating these devices is challenging due to their complex, unintuitive kinematics and the need to avoid sensitive structures in the anatomy. In this paper, we present a motion planning method that computes collision-free motion plans for concentric tube robots at interactive rates. Our method's high speed enables a user to continuously and freely move the robot's tip while the motion planner ensures that the robot's shaft does not collide with any anatomical obstacles. Our approach uses a highly accurate mechanical model of tube interactions, which is important since small movements of the tip position may require large changes in the shape of the device's shaft. Our motion planner achieves its high speed and accuracy by combining offline precomputation of a collision-free roadmap with online position control. We demonstrate our interactive planner in a simulated neurosurgical scenario where a user guides the robot's tip through the environment while the robot automatically avoids collisions with the anatomical obstacles.

  6. Finding Planet Nine: apsidal anti-alignment Monte Carlo results

    NASA Astrophysics Data System (ADS)

    de la Fuente Marcos, C.; de la Fuente Marcos, R.

    2016-10-01

    The distribution of the orbital elements of the known extreme trans-Neptunian objects or ETNOs has been found to be statistically incompatible with that of an unperturbed asteroid population following heliocentric or, better, barycentric orbits. Such trends, if confirmed by future discoveries of ETNOs, strongly suggest that one or more massive perturbers could be located well beyond Pluto. Within the trans-Plutonian planets paradigm, the Planet Nine hypothesis has received much attention as a robust scenario to explain the observed clustering in physical space of the perihelia of seven ETNOs which also exhibit clustering in orbital pole position. Here, we revisit the subject of clustering in perihelia and poles of the known ETNOs using barycentric orbits, and study the visibility of the latest incarnation of the orbit of Planet Nine applying Monte Carlo techniques and focusing on the effects of the apsidal anti-alignment constraint. We provide visibility maps indicating the most likely location of this putative planet if it is near aphelion. We also show that the available data suggest that at least two massive perturbers are present beyond Pluto.

  7. Realistic glottal motion and airflow rate during human breathing.

    PubMed

    Scheinherr, Adam; Bailly, Lucie; Boiron, Olivier; Lagier, Aude; Legou, Thierry; Pichelin, Marine; Caillibotte, Georges; Giovanni, Antoine

    2015-09-01

    The glottal geometry is a key factor in the aerosol delivery efficiency for treatment of lung diseases. However, while glottal vibrations were extensively studied during human phonation, the realistic glottal motion during breathing is poorly understood. Therefore, most current studies assume an idealized steady glottis in the context of respiratory dynamics, and thus neglect the flow unsteadiness related to this motion. This is particularly important to assess the aerosol transport mechanisms in upper airways. This article presents a clinical study conducted on 20 volunteers, to examine the realistic glottal motion during several breathing tasks. Nasofibroscopy was used to investigate the glottal geometrical variations simultaneously with accurate airflow rate measurements. In total, 144 breathing sequences of 30s were recorded. Regarding the whole database, two cases of glottal time-variations were found: "static" or "dynamic" ones. Typically, the peak value of glottal area during slow breathing narrowed from 217 ± 54 mm(2) (mean ± STD) during inspiration, to 178 ± 35 mm(2) during expiration. Considering flow unsteadiness, it is shown that the harmonic approximation of the airflow rate underevaluates the inertial effects as compared to realistic patterns, especially at the onset of the breathing cycle. These measurements provide input data to conduct realistic numerical simulations of laryngeal airflow and particle deposition.

  8. Motion-compensated non-contact detection of heart rate

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Liu, Ming; Dong, Liquan; Zhao, Yuejin; Liu, Xiaohua

    2015-12-01

    A new non-contact heart rate detection method based on the dual-wavelength technique is proposed and demonstrated experimentally. It is a well-known fact that the differences in the circuits of two detection modules result in different responses of two modules for motion artifacts. This poses a great challenge to compensate the motion artifacts during measurements. In order to circumvent this problem, we have proposed the amplitude spectrum and phase spectrum adaptive filter. Comparing with the time-domain adaptive filter and independent component analysis, the amplitude spectrum and phase spectrum adaptive filter can suppress the interference caused by the two circuit differences and effectively compensate the motion artifacts. To make the device is much compact and portable, a photoelectric probe is designed. The measurement distance is from several centimeters up to several meters. Moreover, the data obtained by using this non-contact detection system is compared with those of the conventional finger blood volume pulse (BVP) sensor by simultaneously measuring the heart rate of the subject. The data obtained from the proposed non-contact system are consistent and comparable with that of the BVP sensor.

  9. Rate limiting domain and loop motions in arginine kinase

    PubMed Central

    Davulcu, Omar; Skalicky, Jack J.; Chapman, Michael S.

    2011-01-01

    Arginine kinase catalyzes the reversible transfer of a phosphoryl group between ATP and arginine. It is the arthropod homolog of creatine kinase, buffering cellular ATP levels. Crystal structures of arginine kinase, in substrate-free and substrate-bound forms, have revealed large conformational changes associated with the catalytic cycle. Recent NMR identified movements of the N-terminal domain and a loop comprising residues I182-G209 with conformational exchange rates in the substrate-free enzyme similar to the turnover rate. Here, to understand whether these motions might be rate-limiting, activation barriers for both the intrinsic dynamics and enzyme turnover are determined using measurements over a temperature range of 15 to 30°C. 15N transverse relaxation dispersion yields activation barriers of 46 ± 8 and 34 ± 12 kJ/mol for of the N-terminal domain and I182-G209 loop, respectively. An activation barrier of 34 ± 13 kJ/mol was obtained for enzyme turnover from steady-state kinetics. The similarity between the activation barriers is indeed consistent with turnover being limited by backbone conformational dynamics, and pinpoints the locations of potentially rate limiting motions. PMID:21425868

  10. Heart Rate and Motion Analysis by GPS in Beach Soccer

    PubMed Central

    Castellano, Julen; Casamichana, David

    2010-01-01

    Although beach soccer has become increasingly popular in recent years very little scientific research has been conducted into the sport. A pilot study was carried out with the aim of examining the physiological (heart rate) and physical (motion analysis) responses of beach soccer players during competitive matches. Ten players (age 25.5 ± 0.5 years; height 1.80 ± 0.08 m; weight 78.2 ± 5.6 kg.) were studied over five beach soccer matches. The physiological demands were analysed by measuring heart rate (HR) using telemetric devices, while the physical profile was evaluated by recording motion and speed by means of GPS devices. During competitive matches, players obtained a HRmean of 165.2 bpm (86.5% HRmax), with 59.3% of the time participating (TP) corresponding to values above 90% of the HRmax. The distance covered per minute of participation was 97.7 m, with 9.5% of this distance corresponding to high-intensity running and 2.5% to sprint; the work:rest ratio was 1.4:1 and the maximum speed 21.7 km·h-1. These results showed that beach soccer is an intermittent physical activity of greater intensity than other team games. It requires a major contribution from the anaerobic system as emphasis is placed on players making quick bursts of high-intensity activity separated by brief rest periods. Key points The distance covered per minute of play is around 100 m. Beach soccer is an intermittent sport with a work:rest ratio of 1.4:1. The playing surface in beach soccer is an important handicap to obtain maximum speeds. Beach soccer has a high physiological intensity, with more than half of the game is spent at intensities above 90 % of the HRmax. PMID:24149392

  11. How Fast Is Your Body Motion? Determining a Sufficient Frame Rate for an Optical Motion Tracking System Using Passive Markers.

    PubMed

    Song, Min-Ho; Godøy, Rolf Inge

    2016-01-01

    This paper addresses how to determine a sufficient frame (sampling) rate for an optical motion tracking system using passive reflective markers. When using passive markers for the optical motion tracking, avoiding identity confusion between the markers becomes a problem as the speed of motion increases, necessitating a higher frame rate to avoid a failure of the motion tracking caused by marker confusions and/or dropouts. Initially, one might believe that the Nyquist-Shannon sampling rate estimated from the assumed maximal temporal variation of a motion (i.e. a sampling rate at least twice that of the maximum motion frequency) could be the complete solution to the problem. However, this paper shows that also the spatial distance between the markers should be taken into account in determining the suitable frame rate of an optical motion tracking with passive markers. In this paper, a frame rate criterion for the optical tracking using passive markers is theoretically derived and also experimentally verified using a high-quality optical motion tracking system. Both the theoretical and the experimental results showed that the minimum frame rate is proportional to the ratio between the maximum speed of the motion and the minimum spacing between markers, and may also be predicted precisely if the proportional constant is known in advance. The inverse of the proportional constant is here defined as the tracking efficiency constant and it can be easily determined with some test measurements. Moreover, this newly defined constant can provide a new way of evaluating the tracking algorithm performance of an optical tracking system.

  12. How Fast Is Your Body Motion? Determining a Sufficient Frame Rate for an Optical Motion Tracking System Using Passive Markers

    PubMed Central

    Song, Min-Ho; Godøy, Rolf Inge

    2016-01-01

    This paper addresses how to determine a sufficient frame (sampling) rate for an optical motion tracking system using passive reflective markers. When using passive markers for the optical motion tracking, avoiding identity confusion between the markers becomes a problem as the speed of motion increases, necessitating a higher frame rate to avoid a failure of the motion tracking caused by marker confusions and/or dropouts. Initially, one might believe that the Nyquist-Shannon sampling rate estimated from the assumed maximal temporal variation of a motion (i.e. a sampling rate at least twice that of the maximum motion frequency) could be the complete solution to the problem. However, this paper shows that also the spatial distance between the markers should be taken into account in determining the suitable frame rate of an optical motion tracking with passive markers. In this paper, a frame rate criterion for the optical tracking using passive markers is theoretically derived and also experimentally verified using a high-quality optical motion tracking system. Both the theoretical and the experimental results showed that the minimum frame rate is proportional to the ratio between the maximum speed of the motion and the minimum spacing between markers, and may also be predicted precisely if the proportional constant is known in advance. The inverse of the proportional constant is here defined as the tracking efficiency constant and it can be easily determined with some test measurements. Moreover, this newly defined constant can provide a new way of evaluating the tracking algorithm performance of an optical tracking system. PMID:26967900

  13. Projecting Rate of Change in the Context of Motion onto the Context of Money

    ERIC Educational Resources Information Center

    Wilhelm, Jennifer Anne; Confrey, Jere

    2003-01-01

    This paper reports a study designed to probe the abstraction ability that US Algebra I students can achieve in moving the concepts rate of change and accumulation between motion and money contexts. The Algebra I students used the technologies motion detectors and Interactive Banking software during a replacement unit focused on slope, ratio, and…

  14. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph

    PubMed Central

    Warren, Kristen M.; Harvey, Joshua R.; Chon, Ki H.; Mendelson, Yitzhak

    2016-01-01

    Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data. PMID:26959034

  15. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph.

    PubMed

    Warren, Kristen M; Harvey, Joshua R; Chon, Ki H; Mendelson, Yitzhak

    2016-03-07

    Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data.

  16. 18 CFR 154.206 - Motion to place suspended rates into effect.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of a change of rate, charge, classification, or service for a minimal period and the pipeline has not...(a)(9), that it reserves its right to file motion to place the proposed change of rate, charge... of a change of rate, charge, classification, or service for a minimal period and the pipeline...

  17. Lightweight wrist photoplethysmography for heavy exercise: motion robust heart rate monitoring algorithm

    PubMed Central

    Kim, Insoo

    2015-01-01

    The challenge of heart rate monitoring based on wrist photoplethysmography (PPG) during heavy exercise is addressed. PPG is susceptible to motion artefacts, which have to be mitigated for accurate heart rate estimation. Motion artefacts are particularly apparent for wrist devices, for example, a smart watch, because of the high mobility of the arms. Proposed is a low complexity highly accurate heart rate estimation method for continuous heart rate monitoring using wrist PPG. The proposed method achieved 2.57% mean absolute error in a test data set where subjects ran for a maximum speed of 17 km/h. PMID:26609397

  18. Evaluation of the relationship between motion sickness symptomatology and blood pressure, heart rate, and body temperature

    NASA Technical Reports Server (NTRS)

    Graybiel, A.; Lackner, J. R.

    1980-01-01

    This study investigated the relationship between the development of symptoms of motion sickness and changes in blood pressure, heart rate, and body temperature. Twelve subjects were each evaluated four times using the vestibular-visual interaction test (Graybiel and Lackner, 1980). The results were analyzed both within and across individual subjects. Neither a systematic group nor consistent individual relationship was found between the physiological parameters and the appearance of symptoms of motion sickness. These findings suggest that biofeedback control of the physiological variables studied is not likely to prevent the expression of motion sickness symptomatology.

  19. Heart rate monitoring from wrist-type PPG based on singular spectrum analysis with motion decision.

    PubMed

    Yang Wang; Zhiwen Liu; Bin Dong

    2016-08-01

    Heart rate (HR) monitoring is necessary for daily healthcare. Wrist-type photoplethsmography (PPG) is a convenient and non-invasive technique for HR monitoring. However, motion artifacts (MA) caused by subjects' movements can extremely interfere the results of HR monitoring. In this paper, we propose a high accuracy method using motion decision, singular spectrum analysis (SSA) and spectral peak searching for daily HR estimation. The proposed approach was evaluated on 8 subjects under a series of different motion states. Compared with electrocardiogram (ECG) recorded simultaneously, the experimental results indicated that the averaged absolute estimation error was 2.33 beats per minute (BPM).

  20. Motion sickness in cats - A symptom rating scale used in laboratory and flight tests

    NASA Technical Reports Server (NTRS)

    Suri, K. B.; Daunton, N. G.; Crampton, G. H.

    1979-01-01

    The cat is proposed as a model for the study of motion and space sickness. Development of a scale for rating the motion sickness severity in the cat is described. The scale is used to evaluate an antimotion sickness drug, d-amphetamine plus scopolamine, and to determine whether it is possible to predict sickness susceptibility during parabolic flight, including zero-G maneuvers, from scores obtained during ground based trials.

  1. The Influence of the MPAA's Film Rating System on Motion Picture Attendance: A Pilot Study.

    ERIC Educational Resources Information Center

    Austin, Bruce A.

    A study was undertaken to design and implement an experimental instrument for testing the influence of the Motion Picture Association of America's (MPAA) film rating system on movie attendance. Sixty-five high school students were given synopses of four different fictional films, each of which had been assigned an MPAA rating of G (approved for…

  2. Fuzzy entropy based motion artifact detection and pulse rate estimation for fingertip photoplethysmography.

    PubMed

    Paradkar, Neeraj; Chowdhury, Shubhajit Roy

    2014-01-01

    The paper presents a fingertip photoplethysmography (PPG) based technique to estimate the pulse rate of the subject. The PPG signal obtained from a pulse oximeter is used for the analysis. The input samples are corrupted with motion artifacts due to minor motion of the subjects. Entropy measure of the input samples is used to detect the motion artifacts and estimate the pulse rate. A three step methodology is adapted to identify and classify signal peaks as true systolic peaks or artifact. CapnoBase database and CSL Benchmark database are used to analyze the technique and pulse rate estimation was performed with positive predictive value and sensitivity figures of 99.84% and 99.32% respectively for CapnoBase and 98.83% and 98.84% for CSL database respectively.

  3. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

  4. Motion.

    ERIC Educational Resources Information Center

    Gerhart, James B.; Nussbaum, Rudi H.

    This monograph was written for the Conference on the New Instructional Materials in Physics held at the University of Washington in summer, 1965. It is intended for use in an introductory course in college physics. It consists of an extensive qualitative discussion of motion followed by a detailed development of the quantitative methods needed to…

  5. Sensitive, high-strain, high-rate bodily motion sensors based on graphene-rubber composites.

    PubMed

    Boland, Conor S; Khan, Umar; Backes, Claudia; O'Neill, Arlene; McCauley, Joe; Duane, Shane; Shanker, Ravi; Liu, Yang; Jurewicz, Izabela; Dalton, Alan B; Coleman, Jonathan N

    2014-09-23

    Monitoring of human bodily motion requires wearable sensors that can detect position, velocity and acceleration. They should be cheap, lightweight, mechanically compliant and display reasonable sensitivity at high strains and strain rates. No reported material has simultaneously demonstrated all the above requirements. Here we describe a simple method to infuse liquid-exfoliated graphene into natural rubber to create conducting composites. These materials are excellent strain sensors displaying 10(4)-fold increases in resistance and working at strains exceeding 800%. The sensitivity is reasonably high, with gauge factors of up to 35 observed. More importantly, these sensors can effectively track dynamic strain, working well at vibration frequencies of at least 160 Hz. At 60 Hz, we could monitor strains of at least 6% at strain rates exceeding 6000%/s. We have used these composites as bodily motion sensors, effectively monitoring joint and muscle motion as well and breathing and pulse.

  6. Inspiratory flow rate, not type of incentive spirometry device, influences chest wall motion in healthy individuals.

    PubMed

    Chang, Angela T; Palmer, Kerry R; McNaught, Jessie; Thomas, Peter J

    2010-08-01

    This study investigated the effect of flow rates and spirometer type on chest wall motion in healthy individuals. Twenty-one healthy volunteers completed breathing trials to either two times tidal volume (2xV(T)) or inspiratory capacity (IC) at high, low, or natural flow rates, using a volume- or flow-oriented spirometer. The proportions of rib cage movement to tidal volume (%RC/V(T)), chest wall diameters, and perceived level of exertion (RPE) were compared. Low and natural flow rates resulted in significantly lower %RC/V(T) compared to high flow rate trials (p=0.001) at 2xV(T). Low flow trials also resulted in significantly less chest wall motion in the upper anteroposterior direction than high and natural flow rates (p<0.001). At IC, significantly greater movement occurred in the abdominal lateral direction during low flow compared to high and natural flow trials (both p<0.003). RPE was lower for the low flow trials compared to high flow trials at IC and 2xV(T) (p<0.01). In healthy individuals, inspiratory flow (not device type) during incentive spirometry determines the resultant breathing pattern. High flow rates result in greater chest wall motion than low flow rates.

  7. Alternating Motion Rate as an Index of Speech Motor Disorder in Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Wang, Yu-Tsai; Kent, Ray D.; Duffy, Joseph R.; Thomas, Jack E.; Weismer, Gary

    2004-01-01

    The task of syllable alternating motion rate (AMR) (also called diadochokinesis) is suitable for examining speech disorders of varying degrees of severity and in individuals with varying levels of linguistic and cognitive ability. However, very limited information on this task has been published for subjects with traumatic brain injury (TBI). This…

  8. Frequency-locked pulse sequencer for high-frame-rate monochromatic tissue motion imaging.

    PubMed

    Azar, Reza Zahiri; Baghani, Ali; Salcudean, Septimiu E; Rohling, Robert

    2011-04-01

    To overcome the inherent low frame rate of conventional ultrasound, we have previously presented a system that can be implemented on conventional ultrasound scanners for high-frame-rate imaging of monochromatic tissue motion. The system employs a sector subdivision technique in the sequencer to increase the acquisition rate. To eliminate the delays introduced during data acquisition, a motion phase correction algorithm has also been introduced to create in-phase displacement images. Previous experimental results from tissue- mimicking phantoms showed that the system can achieve effective frame rates of up to a few kilohertz on conventional ultrasound systems. In this short communication, we present a new pulse sequencing strategy that facilitates high-frame-rate imaging of monochromatic motion such that the acquired echo signals are inherently in-phase. The sequencer uses the knowledge of the excitation frequency to synchronize the acquisition of the entire imaging plane to that of an external exciter. This sequencing approach eliminates any need for synchronization or phase correction and has applications in tissue elastography, which we demonstrate with tissue-mimicking phantoms.

  9. Effect of limited amplitude and rate of flap motion on vane-controlled gust alleviation system

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Crawford, D. J.; Sparrow, G. W.

    1972-01-01

    An airplane (light transport type) is assumed to be in level flight (no pitching) through atmospheric turbulence which has a mean-square vertical gust intensity of 9.3 (m/sec)sq. The power spectral density of the vertical acceleration due to gusts is examined with and without a gust-alleviation system in operation. The gust-alleviation system consisted of wing flaps that were used in conjunction with a vane mounted ahead of the airplane to sense the vertical gust velocity. The primary purpose of this study was to examine the change in the effectiveness of the gust-alleviation system when the flap motion is limited in amplitude and rate. The alleviation system was very effective if no restrictions were placed on flap motion (rate and amplitude). Restricting the flap amplitude to 0.5 radian did not appreciably change the effectiveness. However, restricting the flap rate did reduce the gust alleviation, and restricting the flap rate to 0.25 rad/sec actually caused the alleviation system to increase the vertical acceleration above that for the no-alleviation situation. Based upon this analysis, rate limiting appears to be rather significant in gust-alleviation systems designed for passenger comfort.

  10. Motion artifact cancellation and outlier rejection for clip-type ppg-based heart rate sensor.

    PubMed

    Shimazaki, Takunori; Hara, Shinsuke; Okuhata, Hiroyuki; Nakamura, Hajime; Kawabata, Takashi

    2015-01-01

    Heart rate sensing can be used to not only understand exercise intensity but also detect life-critical condition during sports activities. To reduce stress during exercise and attach heart rate sensor easily, we developed a clip-type photoplethysmography (PPG)-based heart rate sensor. The sensor can be attached just by hanging it to the waist part of undershorts, and furthermore, it employs the motion artifact (MA) cancellation technique. However, due to its low contact pressure, sudden jumps and drops, which are called "outliers," are often observed in the sensed heart rate, so we also developed a simple outlier rejection technique. By an experiment using five male subjects (4 sets per subject), we confirmed the MA cancellation and outlier rejection capabilities.

  11. High-frame-rate, motion-compensated 25.4 megapixel image sensor

    NASA Astrophysics Data System (ADS)

    Kamasz, Stacy R.; Farrier, Michael G.; Ma, Shing-Fat F.; Sabila, Robert W.; Chamberlain, Savvas G.

    1994-05-01

    The applicability of large-area full-frame CCD image sensor technology to large optical format aerial reconnaissance applications has been recently demonstrated. The requirements of low-contrast, high-resolution imaging at high frame rates have generated the need for a manufacturable, multitap, small-pitch, wafer-scale CCD image sensor technology. The added requirement of incorporation of electronic motion compensation at the focal plane has generated the need for multisegmented full-frame area array architectures. Characterization results from the newly developed 5040 X 5040 element, eight-tap, full-frame image sensor with multisegmentation for electronic motion compensation are discussed. Experimental determination of resistive-capacitive time constants for metal strapped vertical clock busses on wafer-scale sensors is discussed.

  12. Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

    SciTech Connect

    Fox, C. D.; Kron, T.; Leahy, M.; Duchesne, G.; Williams, S.; Tai, K. H.; Haworth, A.; Herschtal, A.; Foroudi, F.

    2011-11-15

    Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.

  13. Clinical significance of exercise-induced left ventricular wall motion abnormality occurring at a low heart rate

    SciTech Connect

    Kimchi, A.; Rozanski, A.; Fletcher, C.; Maddahi, J.; Swan, H.J.; Berman, D.S.

    1987-10-01

    We studied the relationship between the heart rate at the time of onset of exercise-induced wall motion abnormality and the severity of coronary artery disease in 89 patients who underwent exercise equilibrium radionuclide ventriculography as part of their evaluation for coronary artery disease. Segmental wall motion was scored with a five-point system (3 = normal; -1 = dyskinesis); a decrease of one score defined the onset of wall motion abnormality. The onset of wall motion abnormality at less than or equal to 70% of maximal predicted heart rate had 100% predictive accuracy for coronary artery disease and higher sensitivity than the onset of ischemic ST segment depression at similar heart rate during exercise: 36% (25 of 69 patients with coronary disease) vs 19% (13 of 69 patients), p = 0.01. Wall motion abnormality occurring at less than or equal to 70% of maximal predicted heart rate was present in 49% of patients (23 of 47) with critical stenosis (greater than or equal to 90% luminal diameter narrowing), and in only 5% of patients (2 of 42) without such severe stenosis, p less than 0.001. The sensitivity of exercise-induced wall motion abnormality occurring at a low heart rate for the presence of severe coronary artery disease was similar to that of a deterioration in wall motion by more than two scores during exercise (49% vs 53%) or an absolute decrease of greater than or equal to 5% in exercise left ventricular ejection fraction (49% vs 45%).

  14. Influence of Motion Picture Rating on Adolescent Response to Movie Smoking

    PubMed Central

    Tanski, Susanne; Stoolmiller, Mike

    2012-01-01

    OBJECTIVE: To examine the association between movie smoking exposure (MSE) and adolescent smoking according to rating category. METHODS: A total of 6522 US adolescents were enrolled in a longitudinal survey conducted at 8-month intervals; 5503 subjects were followed up at 8 months, 5019 subjects at 16 months, and 4575 subjects at 24 months. MSE was estimated from 532 recent box-office hits, blocked into 3 Motion Picture Association of America rating categories: G/PG, PG-13, and R. A survival model evaluated time to smoking onset. RESULTS: Median MSE in PG-13–rated movies was ∼3 times higher than median MSE from R-rated movies, but their relation with smoking was essentially the same, with adjusted hazard ratios of 1.49 (95% confidence interval [CI]: 1.23–1.81) and 1.33 (95% CI: 1.23–1.81) for each additional 500 occurrences of MSE respectively. MSE from G/PG-rated movies was small and had no significant relationship with adolescent smoking. Attributable risk estimates showed that adolescent smoking would be reduced by 18% (95% CI: 14–21) if smoking in PG-13–rated movies was reduced to the fifth percentile. In comparison, making all parents maximally authoritative in their parenting would reduce adolescent smoking by 16% (95% CI: 12–19). CONCLUSIONS: The equivalent effect of PG-13-rated and R-rated MSE suggests it is the movie smoking that prompts adolescents to smoke, not other characteristics of R-rated movies or adolescents drawn to them. An R rating for movie smoking could substantially reduce adolescent smoking by eliminating smoking from PG-13 movies. PMID:22778305

  15. Analysis and Visualization of 3D Motion Data for UPDRS Rating of Patients with Parkinson's Disease.

    PubMed

    Piro, Neltje E; Piro, Lennart K; Kassubek, Jan; Blechschmidt-Trapp, Ronald A

    2016-06-21

    Remote monitoring of Parkinson's Disease (PD) patients with inertia sensors is a relevant method for a better assessment of symptoms. We present a new approach for symptom quantification based on motion data: the automatic Unified Parkinson Disease Rating Scale (UPDRS) classification in combination with an animated 3D avatar giving the neurologist the impression of having the patient live in front of him. In this study we compared the UPDRS ratings of the pronation-supination task derived from: (a) an examination based on video recordings as a clinical reference; (b) an automatically classified UPDRS; and (c) a UPDRS rating from the assessment of the animated 3D avatar. Data were recorded using Magnetic, Angular Rate, Gravity (MARG) sensors with 15 subjects performing a pronation-supination movement of the hand. After preprocessing, the data were classified with a J48 classifier and animated as a 3D avatar. Video recording of the movements, as well as the 3D avatar, were examined by movement disorder specialists and rated by UPDRS. The mean agreement between the ratings based on video and (b) the automatically classified UPDRS is 0.48 and with (c) the 3D avatar it is 0.47. The 3D avatar is similarly suitable for assessing the UPDRS as video recordings for the examined task and will be further developed by the research team.

  16. Comparison between red, green and blue light reflection photoplethysmography for heart rate monitoring during motion.

    PubMed

    Lee, Jihyoung; Matsumura, Kenta; Yamakoshi, Ken-ichi; Rolfe, Peter; Tanaka, Shinobu; Yamakoshi, Takehiro

    2013-01-01

    Reflection photoplethysmography (PPG) using 530 nm (green) wavelength light has the potential to be a superior method for monitoring heart rate (HR) during normal daily life due to its relative freedom from artifacts. However, little is known about the accuracy of pulse rate (PR) measured by 530 nm light PPG during motion. Therefore, we compared the HR measured by electrocadiography (ECG) as a reference with PR measured by 530, 645 (red), and 470 nm (blue) wavelength light PPG during baseline and while performing hand waving in 12 participants. In addition, we examined the change of signal-to-noise ratio (SNR) by motion for each of the three wavelengths used for the PPG. The results showed that the limit of agreement in Bland-Altman plots between the HR measured by ECG and PR measured by 530 nm light PPG (±0.61 bpm) was smaller than that achieved when using 645 and 470 nm light PPG (±3.20 bpm and ±2.23 bpm, respectively). The ΔSNR (the difference between baseline and task values) of 530 and 470nm light PPG was significantly smaller than ΔSNR for red light PPG. In conclusion, 530 nm light PPG could be a more suitable method than 645 and 470nm light PPG for monitoring HR in normal daily life.

  17. The effect of electrode surface roughness on the motional heating rate of electromagnetic trapped ions

    NASA Astrophysics Data System (ADS)

    Lin, Kuan-Yu; Low, Guang Hao; Chuang, Isaac

    Electric field noise is a major source of motional heating in trapped ion quantum computation. While it is well known that this noise is influenced by trap electrode geometry in patch potential and surface adsorbate models, this has only been analyzed for smooth surfaces. We investigate the dependence of electric field noise on the roughness of surface electrodes by deriving a Green's function describing this roughness, and evaluating its effects on adsorbate-surface binding energies. At cryogenic temperature, surface roughness is found to exponentially enhance or suppress heating rate, depending on the density distribution of surface adsorbates. Our result suggests that heating rates can be tuned over orders of magnitude by careful engineering of electrode surface profiles.

  18. Real-time 3D ultrasound fetal image enhancment techniques using motion-compensated frame rate up-conversion

    NASA Astrophysics Data System (ADS)

    Lee, Gun-Ill; Park, Rae-Hong; Song, Young-Seuk; Kim, Cheol-An; Hwang, Jae-Sub

    2003-05-01

    In this paper, we present a motion compensated frame rate up-conversion method for real-time three-dimensional (3-D) ultrasound fetal image enhancement. The conventional mechanical scan method with one-dimensional (1-D) array converters used for 3-D volume data acquisition has a slow frame rate of multi-planar images. This drawback is not an issue for stationary objects, however in ultrasound images showing a fetus of more than about 25 weeks, we perceive abrupt changes due to fast motions. To compensate for this defect, we propose the frame rate up-conversion method by which new interpolated frames are inserted between two input frames, giving smooth renditions to human eyes. More natural motions can be obtained by frame rate up-conversion. In the proposed algorithm, we employ forward motion estimation (ME), in which motion vectors (MVs) ar estimated using a block matching algorithm (BMA). To smooth MVs over neighboring blocks, vector median filtering is performed. Using these smoothed MVs, interpolated frames are reconstructed by motion compensation (MC). The undesirable blocking artifacts due to blockwise processing are reduced by block boundary filtering using a Gaussian low pass filter (LPF). The proposed method can be used in computer aided diagnosis (CAD), where more natural 3-D ultrasound images are displayed in real-time. Simulation results with several real test sequences show the effectiveness of the proposed algorithm.

  19. 76 FR 76711 - DCP Raptor Pipeline, LLC; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ...] DCP Raptor Pipeline, LLC; Notice of Motion for Extension of Rate Case Filing Deadline Take notice that on November 30, 2011, DCP Raptor Pipeline, LLC (Raptor) filed a request for an extension consistent..., Raptor requests that the date for its next rate filing be extended to September 1, 2014, which is...

  20. 75 FR 56093 - Eagle Rock Desoto Pipeline, LP; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-15

    ... Energy Regulatory Commission Eagle Rock Desoto Pipeline, LP; Notice of Motion for Extension of Rate Case Filing Deadline September 8, 2010. Take notice that on September 8, 2010, Eagle Rock Desoto Pipeline, L.P. (Eagle Rock) filed a request to extend the date for filing its next rate case to May 1, 2012. Eagle...

  1. 75 FR 70752 - ONEOK WesTex Transmission, LLC; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... Federal Energy Regulatory Commission ONEOK WesTex Transmission, LLC; Notice of Motion for Extension of Rate Case Filing Deadline November 10, 2010. Take notice that on November 2, 2010, ONEOK WesTex Transmission, LLC (OWT) filed a request to extend the date for filing its next rate case to January 3,...

  2. 76 FR 76711 - Overland Trail Transmission, LLC; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ...-003] Overland Trail Transmission, LLC; Notice of Motion for Extension of Rate Case Filing Deadline Take notice that on November 30, 2011, Overland Trail Transmission, LLC (OTTCO) filed a request for an... rates charges by section 311 and Hinshaw pipelines to extend the cycle for such reviews from three...

  3. 76 FR 79170 - Southcross CCNG Transmission Ltd.; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-21

    ... Energy Regulatory Commission Southcross CCNG Transmission Ltd.; Notice of Motion for Extension of Rate Case Filing Deadline Take notice that on December 13, 2011, Southcross CCNG Transmission Ltd... concerning periodic reviews of rates charges by section 311 and Hinshaw pipelines to extend the cycle...

  4. 76 FR 18754 - J-W Pipeline Company; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    ... Energy Regulatory Commission J-W Pipeline Company; Notice of Motion for Extension of Rate Case Filing Deadline Take notice that on March 28, 2011, J-W Pipeline Company (J-W) filed a request for an extension...\\ Therefore, J-W requests that the date for its next rate filing be extended to November 21, 2013, which...

  5. Fast intracellular motion in the living cell by video rate reflection confocal laser scanning microscopy

    PubMed Central

    VESELY, PAVEL; BOYDE, ALAN

    2001-01-01

    Fast intracellular motion (FIM) was first revealed by back scattered light (BSL) imaging in video rate confocal scanning laser microscopy (VRCSLM), beyond the limits of spatial and temporal resolution obtainable with conventional optical microscopy. BSL imaging enabled visualisation of intra and extracellular motion with resolution in space down to 0.2 μm and in time to 1/25th of a second. Mapping the cell space at 0.2 μm×0.2 μm (XY = in instantaneous best focal plane)×0.5 μm (Z = height/depth, optic axis direction) volume steps revealed a communication layer above the known contact layer and an integrated dynamic spatial network (IDSN) towards the cell centre. FIM was originally observed as localised quasichaotic dancing (dithering) or reflecting patches/spots in the cell centre, faster in the darker nuclear space. Later, a second type of FIM was recognised which differed by the presence of a varied proportion of centrifugal and centripetal directional movements and/or jumping of patches/spots in the cell centre and outside the nuclear space. The first type is characteristic for cells in slightly adverse conditions while the second type has so far only been found in eutrophic cells. Temporal speeding up and coarsening of FIM, followed by slowing and eventually cessation at cell death, was found on exposure to strong stressors. It was concluded that the state of FIM provides instantaneous information about individual cell reactions to actual treatment and about cell survival. A putative switch between the first and second type FIM could be considered as an indicator of timing of cellular processes. The significance of FIM for the biology of the cell is seen in the rapid assessment of the condition of an individual live cell investigated by combination of various methods. Requirements for further development of this approach are outlined. PMID:11465857

  6. Quality Control of Structural MRI Images Applied Using FreeSurfer—A Hands-On Workflow to Rate Motion Artifacts

    PubMed Central

    Backhausen, Lea L.; Herting, Megan M.; Buse, Judith; Roessner, Veit; Smolka, Michael N.; Vetter, Nora C.

    2016-01-01

    In structural magnetic resonance imaging motion artifacts are common, especially when not scanning healthy young adults. It has been shown that motion affects the analysis with automated image-processing techniques (e.g., FreeSurfer). This can bias results. Several developmental and adult studies have found reduced volume and thickness of gray matter due to motion artifacts. Thus, quality control is necessary in order to ensure an acceptable level of quality and to define exclusion criteria of images (i.e., determine participants with most severe artifacts). However, information about the quality control workflow and image exclusion procedure is largely lacking in the current literature and the existing rating systems differ. Here, we propose a stringent workflow of quality control steps during and after acquisition of T1-weighted images, which enables researchers dealing with populations that are typically affected by motion artifacts to enhance data quality and maximize sample sizes. As an underlying aim we established a thorough quality control rating system for T1-weighted images and applied it to the analysis of developmental clinical data using the automated processing pipeline FreeSurfer. This hands-on workflow and quality control rating system will aid researchers in minimizing motion artifacts in the final data set, and therefore enhance the quality of structural magnetic resonance imaging studies. PMID:27999528

  7. SU-E-T-244: Motion Control Challenges in High Dose Rate Brachytherapy

    SciTech Connect

    Hyvarinen, M; Leventouri, T; Pella, S; Dumitru, N

    2014-06-01

    Purpose: High dose rate (HDR) brachytherapy dose distribution is highly localized and has a very sharp fall-off. Thus the one of the most important part of the treatment is the localization and immobilization of the applicator from the implantation to the setup verification to the treatment delivery. The smallest motions of the patient can induce a small rotation, tilt, or translational movement of the applicator that can convert into miss of a significant part of the tumor or to over irradiating a nearby critical organ.The purpose of this study is to revise most of the HDR types of treatments with their applicators and their localization challenges. Since every millimeter of misplacement counts the study will look into the necessity of increasing the immobilization for several types of applicators. Methods: The study took over 136 plans generated by the treatment planning system (TPS) looking into the applicator placement in regard to the organs at risk (OR) and simulated the three possible displacements at the hottest dose point on the critical organ for several accessories to evaluate the variation of the delivered dose at the point due to the displacement. Results: Many of the present immobilization devices produced for external radiotherapy can be used to improve the localization of HDR applicators during transportation of the patient and during treatment. Conclusion: This study data indicates that an improvement of the immobilization devices for HDR is absolutely necessary. Better applicator fixation devices are required too. Developing new immobilization devices for all the applicators is recommended.

  8. Physiological demands of women's rugby union: time-motion analysis and heart rate response.

    PubMed

    Virr, Jody Lynn; Game, Alex; Bell, Gordon John; Syrotuik, Daniel

    2014-01-01

    The aim of this study was to determine the physical demands of women's rugby union match play using time-motion analysis and heart rate (HR) response. Thirty-eight premier club level female rugby players, ages 18-34 years were videotaped and HRs monitored for a full match. Performances were coded into 12 different movement categories: 5 speeds of locomotion (standing, walking, jogging, striding, sprinting), 4 forms of intensive non-running exertion (ruck/maul/tackle, pack down, scrum, lift) and 3 discrete activities (kick, jump, open field tackle). The main results revealed that backs spend significantly more time sprinting and walking whereas forwards spend more time in intensive non-running exertion and jogging. Forwards also had a significantly higher total work frequency compared to the backs, but a higher total rest frequency compared to the backs. In terms of HR responses, forwards displayed higher mean HRs throughout the match and more time above 80% of their maximum HR than backs. In summary, women's rugby union is characterised by intermittent bursts of high-intensity activity, where forwards and backs have similar anaerobic energy demands, but different specific match demands.

  9. 76 FR 39869 - Lee 8 Storage Partnership; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Energy Regulatory Commission Lee 8 Storage Partnership; Notice of Motion for Extension of Rate Case Filing Deadline Take notice that on June 27, 2011, Lee 8 Storage Partnership (Lee 8) filed a request for.... Eastern Time on Monday, July 11, 2011. Dated: June 28, 2011. Nathaniel J. Davis, Sr., Deputy...

  10. 76 FR 36913 - Washington Gas Light Company; Notice of Motion for Extension of Rate Case Filing Deadline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Washington Gas Light Company; Notice of Motion for Extension of Rate Case Filing Deadline Take notice that on June 15, 2011, Washington Gas Light Company (Washington Gas) filed...

  11. Ride quality - An exploratory study and criteria development. [visual motion simulator measurement of response ratings of ride quality of aircraft

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1974-01-01

    The Langley six degree of freedom visual motion simulator has been used to measure subjective response ratings of the ride quality of eight segments of flight, representative of a wide variation in comfort estimates. The results indicate that the use of simulators for this purpose appears promising. A preliminary approach for the development of criteria for ride quality ratings based on psychophysical precepts is included.

  12. Time-motion analysis, heart rate, and physiological characteristics of international canoe polo athletes.

    PubMed

    Forbes, Scott C; Kennedy, Michael D; Bell, Gordon J

    2013-10-01

    To evaluate the time international canoe polo players spend performing various game activities, measure heart rate (HR) responses during games, and describe the physiological profile of elite players. Eight national canoe polo players were videotaped and wore HR monitors during 3 games at a World Championship and underwent fitness testing. The mean age, height, and weight were 25 ± 1 years, 1.82 ± 0.04 m, and 81.9 ± 10.9 kg, respectively. Time-motion analysis of 3 games indicated that the players spent 29 ± 3% of the game slow and moderate forward paddling, 28 ± 5% contesting, 27 ± 5% resting and gliding, 7 ± 1% turning, 5 ± 1% backward paddling, 2 ± 1% sprinting, and 2 ± 1% dribbling. Sixty-nine (±20)% of the game time was played at an HR intensity above the HR that corresponded to the ventilatory threshold (VT) that was determined during the peak V[Combining Dot Above]O2 test. Peak oxygen uptake and VT were 3.3 ± 0.3 and 2.2 ± 0.3 L·min, respectively, on a modified Monark arm crank ergometer. Arm crank peak 5-second anaerobic power was 379 W. The majority of the time spent during international canoe polo games involved slow-to-moderate forward paddling, contesting for the ball, and resting and gliding. Canoe polo games are played at a high intensity indicated by the HR responses, and the physiological characteristics suggest that these athletes had high levels of upper body aerobic and anaerobic fitness levels.

  13. Seismic hazard in Hawaii: High rate of large earthquakes and probabilistics ground-motion maps

    USGS Publications Warehouse

    Klein, F.W.; Frankel, A.D.; Mueller, C.S.; Wesson, R.L.; Okubo, P.G.

    2001-01-01

    The seismic hazard and earthquake occurrence rates in Hawaii are locally as high as that near the most hazardous faults elsewhere in the United States. We have generated maps of peak ground acceleration (PGA) and spectral acceleration (SA) (at 0.2, 0.3 and 1.0 sec, 5% critical damping) at 2% and 10% exceedance probabilities in 50 years. The highest hazard is on the south side of Hawaii Island, as indicated by the MI 7.0, MS 7.2, and MI 7.9 earthquakes, which occurred there since 1868. Probabilistic values of horizontal PGA (2% in 50 years) on Hawaii's south coast exceed 1.75g. Because some large earthquake aftershock zones and the geometry of flank blocks slipping on subhorizontal decollement faults are known, we use a combination of spatially uniform sources in active flank blocks and smoothed seismicity in other areas to model seismicity. Rates of earthquakes are derived from magnitude distributions of the modem (1959-1997) catalog of the Hawaiian Volcano Observatory's seismic network supplemented by the historic (1868-1959) catalog. Modern magnitudes are ML measured on a Wood-Anderson seismograph or MS. Historic magnitudes may add ML measured on a Milne-Shaw or Bosch-Omori seismograph or MI derived from calibrated areas of MM intensities. Active flank areas, which by far account for the highest hazard, are characterized by distributions with b slopes of about 1.0 below M 5.0 and about 0.6 above M 5.0. The kinked distribution means that large earthquake rates would be grossly under-estimated by extrapolating small earthquake rates, and that longer catalogs are essential for estimating or verifying the rates of large earthquakes. Flank earthquakes thus follow a semicharacteristic model, which is a combination of background seismicity and an excess number of large earthquakes. Flank earthquakes are geometrically confined to rupture zones on the volcano flanks by barriers such as rift zones and the seaward edge of the volcano, which may be expressed by a magnitude

  14. EFFECTS OF TURBULENCE, ECCENTRICITY DAMPING, AND MIGRATION RATE ON THE CAPTURE OF PLANETS INTO MEAN MOTION RESONANCE

    SciTech Connect

    Ketchum, Jacob A.; Adams, Fred C.; Bloch, Anthony M.

    2011-01-01

    Pairs of migrating extrasolar planets often lock into mean motion resonance as they drift inward. This paper studies the convergent migration of giant planets (driven by a circumstellar disk) and determines the probability that they are captured into mean motion resonance. The probability that such planets enter resonance depends on the type of resonance, the migration rate, the eccentricity damping rate, and the amplitude of the turbulent fluctuations. This problem is studied both through direct integrations of the full three-body problem and via semi-analytic model equations. In general, the probability of resonance decreases with increasing migration rate, and with increasing levels of turbulence, but increases with eccentricity damping. Previous work has shown that the distributions of orbital elements (eccentricity and semimajor axis) for observed extrasolar planets can be reproduced by migration models with multiple planets. However, these results depend on resonance locking, and this study shows that entry into-and maintenance of-mean motion resonance depends sensitively on the migration rate, eccentricity damping, and turbulence.

  15. Complexity control of fast motion estimation in H.264/MPEG-4 AVC with rate-distortion-complexity optimization

    NASA Astrophysics Data System (ADS)

    Wu, Mo; Forchhammer, Søren; Aghito, Shankar M.

    2007-01-01

    A complexity control algorithm for H.264 advanced video coding is proposed. The algorithm can control the complexity of integer inter motion estimation for a given target complexity. The Rate-Distortion-Complexity performance is improved by a complexity prediction model, simple analysis of the past statistics and a control scheme. The algorithm also works well for scene change condition. Test results for coding interlaced video (720 x576 PAL) are reported.

  16. The effects of autogenic-feedback training on motion sickness severity and heart rate variability in astronauts

    NASA Technical Reports Server (NTRS)

    Toscano, William B.; Cowings, Patricia S.

    1994-01-01

    Space motion sickness (SMS) affects 50 percent of all people during early days of spaceflight. This study describes the results of two Shuttle flight experiments in which autogenic-feedback training (AFT), a physiological conditioning method, was tested as a treatment for this disorder. Of the six who were designated as flight subjects (two women and four men), three were given treatment and three served as controls (i.e., no AFT). Treatment subjects were given 6 hours of preflight AFT. Preflight results showed that AFT produced a significant increase in tolerance to rotating chair motion sickness tests. Further, this increased tolerance was associated with changes in specific physiological responses and reports of reduced malaise. Flight results showed that two of the three control subjects experienced repeated vomiting on the first mission day, while one subject experienced only moderate malaise. Of the three treatment subjects, one experienced mild discomfort, one moderate discomfort, and one severe motion sickness. Only the three control subjects took medication for symptom suppression. Measures of cardiac function reflective of vagal control were shown to be affected especially strongly on the first day of space flight. AFT given for control of heart rate, respiration, and other autonomic activity influenced both the vagal control measures and SMS. These data suggest that AFT may be an effective treatment for space motion sickness; however, this cannot be demonstrated conclusively with the small number of subjects described.

  17. Quantifying melt production and degassing rate at mid-ocean ridges from global mantle convection models with plate motion history

    NASA Astrophysics Data System (ADS)

    Li, Mingming; Black, Benjamin; Zhong, Shijie; Manga, Michael; Rudolph, Maxwell L.; Olson, Peter

    2016-07-01

    The Earth's surface volcanism exerts first-order controls on the composition of the atmosphere and the climate. On Earth, the majority of surface volcanism occurs at mid-ocean ridges. In this study, based on the dependence of melt fraction on temperature, pressure, and composition, we compute melt production and degassing rate at mid-ocean ridges from three-dimensional global mantle convection models with plate motion history as the surface velocity boundary condition. By incorporating melting in global mantle convection models, we connect deep mantle convection to surface volcanism, with deep and shallow mantle processes internally consistent. We compare two methods to compute melt production: a tracer method and an Eulerian method. Our results show that melt production at mid-ocean ridges is mainly controlled by surface plate motion history, and that changes in plate tectonic motion, including plate reorganizations, may lead to significant deviation of melt production from the expected scaling with seafloor production rate. We also find a good correlation between melt production and degassing rate beneath mid-ocean ridges. The calculated global melt production and CO2 degassing rate at mid-ocean ridges varies by as much as a factor of 3 over the past 200 Myr. We show that mid-ocean ridge melt production and degassing rate would be much larger in the Cretaceous, and reached maximum values at ˜150-120 Ma. Our results raise the possibility that warmer climate in the Cretaceous could be due in part to high magmatic productivity and correspondingly high outgassing rates at mid-ocean ridges during that time.

  18. Inverse synthetic aperture radar imaging of targets with complex motions based on modified chirp rate-quadratic chirp rate distribution for cubic phase signal

    NASA Astrophysics Data System (ADS)

    Yanyan, Li; Tao, Su; Jibin, Zheng

    2015-01-01

    For targets with complex motions, the time-varying Doppler frequency deteriorates inverse synthetic aperture radar (ISAR) images. After range alignment and phase adjustment, azimuth echoes in a range cell can be modeled as multicomponent cubic phase signals (CPSs). The chirp rate and the quadratic chirp rate of the CPS are identified as the causes of the time-varying Doppler frequency; thus, it is necessary to estimate these two parameters correctly to obtain a well-focused ISAR image. The parameter-estimation algorithm based on the modified chirp rate-quadratic chirp rate distribution (M-CRQCRD) is proposed for the CPS and applied to the ISAR imaging of targets with complex motions. The computational cost of M-CRQCRD is low, because it can be implemented by the fast Fourier transform (FFT) and the nonuniform FFT easily. Compared to two representative parameter-estimation algorithms, the M-CRQCRD can acquire a higher antinoise performance due to the introduction of an optimal lag-time. Through simulations and analyses for the synthetic radar data, the effectiveness of the M-CRQCRD and the imaging algorithm based on the M-CRQCRD are verified.

  19. Auger decay rates of core hole states using equation of motion coupled cluster method

    NASA Astrophysics Data System (ADS)

    Ghosh, Aryya; Vaval, Nayana; Pal, Sourav

    2017-01-01

    The recent development of Linac coherent light source high intense X-ray laser makes it possible to create double core ionization in the molecule. The generation of double core hole state and its decay is identified by Auger spectroscopy. The decay of this double core hole (DCH) states can be used as a powerful spectroscopic tool in chemical analysis. In the present work, we have implemented a promising approach, known as CAP-EOMCC method, which is a combination of complex absorbing potential (CAP) and equation-of-motion coupled cluster (EOMCC) approach to calculate the lifetime of single and double core hole states. We have applied this method to calculate the lifetime of the single core hole (K-LL) and double core hole (KK-KLL) states of CH4, NH3 and HF molecules. The predicted lifetime is found to be extremely short.

  20. A Robust Random Forest-Based Approach for Heart Rate Monitoring Using Photoplethysmography Signal Contaminated by Intense Motion Artifacts

    PubMed Central

    Ye, Yalan; He, Wenwen; Cheng, Yunfei; Huang, Wenxia; Zhang, Zhilin

    2017-01-01

    The estimation of heart rate (HR) based on wearable devices is of interest in fitness. Photoplethysmography (PPG) is a promising approach to estimate HR due to low cost; however, it is easily corrupted by motion artifacts (MA). In this work, a robust approach based on random forest is proposed for accurately estimating HR from the photoplethysmography signal contaminated by intense motion artifacts, consisting of two stages. Stage 1 proposes a hybrid method to effectively remove MA with a low computation complexity, where two MA removal algorithms are combined by an accurate binary decision algorithm whose aim is to decide whether or not to adopt the second MA removal algorithm. Stage 2 proposes a random forest-based spectral peak-tracking algorithm, whose aim is to locate the spectral peak corresponding to HR, formulating the problem of spectral peak tracking into a pattern classification problem. Experiments on the PPG datasets including 22 subjects used in the 2015 IEEE Signal Processing Cup showed that the proposed approach achieved the average absolute error of 1.65 beats per minute (BPM) on the 22 PPG datasets. Compared to state-of-the-art approaches, the proposed approach has better accuracy and robustness to intense motion artifacts, indicating its potential use in wearable sensors for health monitoring and fitness tracking. PMID:28212327

  1. A Robust Random Forest-Based Approach for Heart Rate Monitoring Using Photoplethysmography Signal Contaminated by Intense Motion Artifacts.

    PubMed

    Ye, Yalan; He, Wenwen; Cheng, Yunfei; Huang, Wenxia; Zhang, Zhilin

    2017-02-16

    The estimation of heart rate (HR) based on wearable devices is of interest in fitness. Photoplethysmography (PPG) is a promising approach to estimate HR due to low cost; however, it is easily corrupted by motion artifacts (MA). In this work, a robust approach based on random forest is proposed for accurately estimating HR from the photoplethysmography signal contaminated by intense motion artifacts, consisting of two stages. Stage 1 proposes a hybrid method to effectively remove MA with a low computation complexity, where two MA removal algorithms are combined by an accurate binary decision algorithm whose aim is to decide whether or not to adopt the second MA removal algorithm. Stage 2 proposes a random forest-based spectral peak-tracking algorithm, whose aim is to locate the spectral peak corresponding to HR, formulating the problem of spectral peak tracking into a pattern classification problem. Experiments on the PPG datasets including 22 subjects used in the 2015 IEEE Signal Processing Cup showed that the proposed approach achieved the average absolute error of 1.65 beats per minute (BPM) on the 22 PPG datasets. Compared to state-of-the-art approaches, the proposed approach has better accuracy and robustness to intense motion artifacts, indicating its potential use in wearable sensors for health monitoring and fitness tracking.

  2. Slip-rate measurements on the Karakorum Fault may imply secular variations in fault motion.

    PubMed

    Chevalier, M-L; Ryerson, F J; Tapponnier, P; Finkel, R C; Van Der Woerd, J; Haibing, Li; Qing, Liu

    2005-01-21

    Beryllium-10 surface exposure dating of offset moraines on one branch of the Karakorum Fault west of the Gar basin yields a long-term (140- to 20-thousand-year) right-lateral slip rate of approximately 10.7 +/- 0.7 millimeters per year. This rate is 10 times larger than that inferred from recent InSAR analyses ( approximately 1 +/- 3 millimeters per year) that span approximately 8 years and sample all branches of the fault. The difference in slip-rate determinations suggests that large rate fluctuations may exist over centennial or millennial time scales. Such fluctuations would be consistent with mechanical coupling between the seismogenic, brittle-creep, and ductile shear sections of faults that reach deep into the crust.

  3. Comparative evaluation of susceptibility to motion artifact in different wearable systems for monitoring respiratory rate.

    PubMed

    Lanatà, Antonio; Scilingo, Enzo Pasquale; Nardini, Elena; Loriga, Giannicola; Paradiso, Rita; De-Rossi, Danilo

    2010-03-01

    The purpose of this study is to comparatively evaluate the performance of different wearable systems based on indirect breathing monitoring in terms of susceptibility to motion artifacts. These performances are compared with direct respiratory measurements using a spirometer, which is accurate, reliable, and less sensitive to movement artifacts, but cannot be integrated into truly wearable form. Experiments were carried out on four indirect methods implemented into wearable systems, inductive plethysmography, impedance plethysmography, piezoresistive pneumography, and piezoelectric pneumography, to ascertain the performance of each of them in terms of noise due to movement artifacts, as well as to study the effects of different movements or gestures during each test. A group of volunteers was asked to wear all of the breath monitoring systems simultaneously along with the face mask of the spirometer while carrying out four physical exercises in a gym under controlled conditions. Data are analyzed in the time and frequency domain to estimate the frequency respiration from each wearable system and compare it with those of the spirometer. Results confirmed that all the wearable systems are somehow affected by movement artifacts, but statistical investigation showed that for most of the physical exercises, three out of four, piezoelectric pneumography provided best performance in terms of robustness and reduced susceptibility to movement artifacts.

  4. The forward rate of binding of surface-tethered reactants: effect of relative motion between two surfaces.

    PubMed Central

    Chang, K C; Hammer, D A

    1999-01-01

    The reaction of molecules confined to two dimensions is of interest in cell adhesion, specifically for the reaction between cell surface receptors and substrate-bound ligand. We have developed a model to describe the overall rate of reaction of species that are bound to surfaces under relative motion, such that the Peclet number is order one or greater. The encounter rate between reactive species is calculated from solution of the two-dimensional convection-diffusion equation. The probability that each encounter will lead to binding depends on the intrinsic rate of reaction and the encounter duration. The encounter duration is obtained from the theory of first passage times. We find that the binding rate increases with relative velocity between the two surfaces, then reaches a plateau. This plateau indicates that the increase in the encounter rate is counterbalanced by the decrease in the encounter duration as the relative velocity increases. The binding rate is fully described by two dimensionless parameters, the Peclet number and the Damköhler number. We use this model to explain data from the cell adhesion literature by incorporating these rate laws into "adhesive dynamics" simulations to model the binding of a cell to a surface under flow. Leukocytes are known to display a "shear threshold effect" when binding selectin-coated surfaces under shear flow, defined as an increase in bind rate with shear; this effect, as calculated here, is due to an increase in collisions between receptor and ligand with increasing shear. The model can be used to explain other published data on the effect of wall shear rate on the binding of cells to surfaces, specifically the mild decrease in binding within a fixed area with increasing shear rate. PMID:10049312

  5. Analysis and Visualization of 3D Motion Data for UPDRS Rating of Patients with Parkinson’s Disease

    PubMed Central

    Piro, Neltje E.; Piro, Lennart K.; Kassubek, Jan; Blechschmidt-Trapp, Ronald A.

    2016-01-01

    Remote monitoring of Parkinson’s Disease (PD) patients with inertia sensors is a relevant method for a better assessment of symptoms. We present a new approach for symptom quantification based on motion data: the automatic Unified Parkinson Disease Rating Scale (UPDRS) classification in combination with an animated 3D avatar giving the neurologist the impression of having the patient live in front of him. In this study we compared the UPDRS ratings of the pronation-supination task derived from: (a) an examination based on video recordings as a clinical reference; (b) an automatically classified UPDRS; and (c) a UPDRS rating from the assessment of the animated 3D avatar. Data were recorded using Magnetic, Angular Rate, Gravity (MARG) sensors with 15 subjects performing a pronation-supination movement of the hand. After preprocessing, the data were classified with a J48 classifier and animated as a 3D avatar. Video recording of the movements, as well as the 3D avatar, were examined by movement disorder specialists and rated by UPDRS. The mean agreement between the ratings based on video and (b) the automatically classified UPDRS is 0.48 and with (c) the 3D avatar it is 0.47. The 3D avatar is similarly suitable for assessing the UPDRS as video recordings for the examined task and will be further developed by the research team. PMID:27338400

  6. A hip joint simulator study using simplified loading and motion cycles generating physiological wear paths and rates.

    PubMed

    Barbour, P S; Stone, M H; Fisher, J

    1999-01-01

    In some designs of hip joint simulator the cost of building a highly complex machine has been offset with the requirement for a large number of test stations. The application of the wear results generated by these machines depends on their ability to reproduce physiological wear rates and processes. In this study a hip joint simulator has been shown to reproduce physiological wear using only one load vector and two degrees of motion with simplified input cycles. The actual path of points on the femoral head relative to the acetabular cup were calculated and compared for physiological and simplified input cycles. The in vitro wear rates were found to be highly dependent on the shape of these paths and similarities could be drawn between the shape of the physiological paths and the simplified elliptical paths.

  7. Magma production rate along the Ninetyeast Ridge and its relationship to Indian plate motion and Kerguelen hot spot activity

    NASA Astrophysics Data System (ADS)

    Sreejith, K. M.; Krishna, K. S.

    2015-02-01

    The Ninetyeast Ridge, a linear trace of the Kerguelen hot spot in the Indian Ocean, was emplaced on a rapidly drifting Indian plate. Magma production rates along the ridge track are computed using gravity-derived excess crustal thickness data. The production rates change between 2 and 15 m3/s over timescales of 3-16 Myr. Major variations in magma production rates are primarily associated with significant changes in the Indian plate velocity with low-production phases linked to high plate velocity periods. The lowest magma production rate (2 m3/s) at 62 Ma is associated with the rapid northward drift of Indian plate under the influence of the Reunion mantle plume. The contemporaneous slowing of the African plate coincides with increase in magma production rate along the Walvis Ridge in the Atlantic Ocean. The present study suggests that variations in the Indian plate motion and frequent ridge jumps have a major role in controlling the magma production, particularly on long-period cycles (~16 Myr). Short-period variations (~5 Myr) in magma productions may be associated with intrinsic changes in the plume, possibly due to the presence of solitary waves in the plume conduit.

  8. A novel machine learning-enabled framework for instantaneous heart rate monitoring from motion-artifact-corrupted electrocardiogram signals.

    PubMed

    Zhang, Qingxue; Zhou, Dian; Zeng, Xuan

    2016-11-01

    This paper proposes a novel machine learning-enabled framework to robustly monitor the instantaneous heart rate (IHR) from wrist-electrocardiography (ECG) signals continuously and heavily corrupted by random motion artifacts in wearable applications. The framework includes two stages, i.e. heartbeat identification and refinement, respectively. In the first stage, an adaptive threshold-based auto-segmentation approach is proposed to select out heartbeat candidates, including the real heartbeats and large amounts of motion-artifact-induced interferential spikes. Then twenty-six features are extracted for each candidate in time, spatial, frequency and statistical domains, and evaluated by a spare support vector machine (SVM) to select out ten critical features which can effectively reveal residual heartbeat information. Afterwards, an SVM model, created on the training data using the selected feature set, is applied to find high confident heartbeats from a large number of candidates in the testing data. In the second stage, the SVM classification results are further refined by two steps: (1) a rule-based classifier with two attributes named 'continuity check' and 'locality check' for outlier (false positives) removal, and (2) a heartbeat interpolation strategy for missing-heartbeat (false negatives) recovery. The framework is evaluated on a wrist-ECG dataset acquired by a semi-customized platform and also a public dataset. When the signal-to-noise ratio is as low as  -7 dB, the mean absolute error of the estimated IHR is 1.4 beats per minute (BPM) and the root mean square error is 6.5 BPM. The proposed framework greatly outperforms well-established approaches, demonstrating that it can effectively identify the heartbeats from ECG signals continuously corrupted by intense motion artifacts and robustly estimate the IHR. This study is expected to contribute to robust long-term wearable IHR monitoring for pervasive heart health and fitness management.

  9. A multi-channel opto-electronic sensor to accurately monitor heart rate against motion artefact during exercise.

    PubMed

    Alzahrani, Abdullah; Hu, Sijung; Azorin-Peris, Vicente; Barrett, Laura; Esliger, Dale; Hayes, Matthew; Akbare, Shafique; Achart, Jérôme; Kuoch, Sylvain

    2015-10-12

    This study presents the use of a multi-channel opto-electronic sensor (OEPS) to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare. The aim of this work was to study how to capture the heart rate (HR) efficiently through a well-constructed OEPS and a 3-axis accelerometer with wireless communication. A protocol was designed to incorporate sitting, standing, walking, running and cycling. The datasets collected from these activities were processed to elaborate sport physiological effects. t-test, Bland-Altman Agreement (BAA), and correlation to evaluate the performance of the OEPS were used against Polar and Mio-Alpha HR monitors. No differences in the HR were found between OEPS, and either Polar or Mio-Alpha (both p > 0.05); a strong correlation was found between Polar and OEPS (r: 0.96, p < 0.001); the bias of BAA 0.85 bpm, the standard deviation (SD) 9.20 bpm, and the limits of agreement (LOA) from -17.18 bpm to +18.88 bpm. For the Mio-Alpha and OEPS, a strong correlation was found (r: 0.96, p < 0.001); the bias of BAA 1.63 bpm, SD 8.62 bpm, LOA from -15.27 bpm to +18.58 bpm. These results demonstrate the OEPS to be capable of carrying out real time and remote monitoring of heart rate.

  10. A Multi-Channel Opto-Electronic Sensor to Accurately Monitor Heart Rate against Motion Artefact during Exercise

    PubMed Central

    Alzahrani, Abdullah; Hu, Sijung; Azorin-Peris, Vicente; Barrett, Laura; Esliger, Dale; Hayes, Matthew; Akbare, Shafique; Achart, Jérôme; Kuoch, Sylvain

    2015-01-01

    This study presents the use of a multi-channel opto-electronic sensor (OEPS) to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare. The aim of this work was to study how to capture the heart rate (HR) efficiently through a well-constructed OEPS and a 3-axis accelerometer with wireless communication. A protocol was designed to incorporate sitting, standing, walking, running and cycling. The datasets collected from these activities were processed to elaborate sport physiological effects. t-test, Bland-Altman Agreement (BAA), and correlation to evaluate the performance of the OEPS were used against Polar and Mio-Alpha HR monitors. No differences in the HR were found between OEPS, and either Polar or Mio-Alpha (both p > 0.05); a strong correlation was found between Polar and OEPS (r: 0.96, p < 0.001); the bias of BAA 0.85 bpm, the standard deviation (SD) 9.20 bpm, and the limits of agreement (LOA) from −17.18 bpm to +18.88 bpm. For the Mio-Alpha and OEPS, a strong correlation was found (r: 0.96, p < 0.001); the bias of BAA 1.63 bpm, SD 8.62 bpm, LOA from −15.27 bpm to +18.58 bpm. These results demonstrate the OEPS to be capable of carrying out real time and remote monitoring of heart rate. PMID:26473860

  11. Effects of Three Recovery Protocols on Range of Motion, Heart Rate, Rating of Perceived Exertion, and Blood Lactate in Baseball Pitchers During a Simulated Game.

    PubMed

    Warren, Courtney D; Szymanski, David J; Landers, Merrill R

    2015-11-01

    Baseball pitching has been described as an anaerobic activity from a bioenergetics standpoint with short bouts of recovery. Depending on the physical conditioning and muscle fiber composition of the pitcher as well as the number of pitches thrown per inning and per game, there is the possibility of pitchers fatiguing during a game, which could lead to a decrease in pitching performance. Therefore, the purpose of this study was to evaluate the effects of 3 recovery protocols: passive recovery, active recovery (AR), and electrical muscle stimulation (EMS) on range of motion (ROM), heart rate (HR), rating of perceived exertion (RPE), and blood lactate concentration in baseball pitchers during a simulated game. Twenty-one Division I intercollegiate baseball pitchers (age = 20.4 ± 1.4 years; height = 185.9 ± 8.4 cm; weight = 86.5 ± 8.9 kg; percent body fat = 11.2 ± 2.6) volunteered to pitch 3 simulated 5-inning games, with a maximum of 70 fastballs thrown per game while wearing an HR monitor. Range of motion was measured pre, post, and 24 hours postpitching for shoulder internal and external rotation at 90° and elbow flexion and extension. Heart rate was recorded after each pitch and after every 30 seconds of the 6-minute recovery period. Rating of perceived exertion was recorded after the last pitch of each inning and after completing each 6-minute recovery period. Immediately after throwing the last pitch of each inning, postpitching blood lactate concentration (PPLa-) was measured. At the end of the 6-minute recovery period, before the next inning started, postrecovery blood lactate concentration (PRLa-) was measured. Pitchers were instructed to throw each pitch at or above 95% of their best-pitched fastball. This was enforced to ensure that each pitcher was throwing close to maximal effort for all 3 simulated games. All data presented represent group mean values. Results revealed that the method of recovery protocol did not significantly influence ROM (p > 0

  12. Modulation of the reaction rate of regulating protein induces large morphological and motional change of amoebic cell.

    PubMed

    Nishimura, Shin I; Sasai, Masaki

    2007-03-21

    Morphologies of moving amoebae are categorized into two types. One is the "neutrophil" type in which the long axis of cell roughly coincides with its moving direction. This type of cell extends a leading edge at the front and retracts a narrow tail at the rear, whose shape has been often drawn as a typical amoeba in textbooks. The other one is the "keratocyte" type with widespread lamellipodia along the front side arc. Short axis of cell in this type roughly coincides with its moving direction. In order to understand what kind of molecular feature causes conversion between two types of morphologies, and how two typical morphologies are maintained, a mathematical model of amoebic cells is developed. This model describes movement of cell and intracellular reactions of activator, inhibitor and actin filaments in a unified way. It is found that the producing rate of activator is a key factor of conversion between two types. This model also explains the observed data that the keratocyte type cells tend to rapidly move along a straight line. The neutrophil type cells move along a straight line when the moving velocity is small, but they show fluctuated motions deviating from a line when they move as fast as the keratocyte type cells. Efficient energy consumption in the neutrophil type cells is predicted.

  13. Development of the wake behind a circular cylinder impulsively started into rotatory and rectilinear motion: Intermediate rotation rates

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Ming; Ou, Yuh-Roung; Pearlstein, Arne J.

    1991-01-01

    The temporal development of two-dimensional viscous incompressible flow generated by a circular cylinder started impulsively into steady rotatory and rectilinear motion is studied by integration of a velocity/vorticity formulation of the governing equations, using an explicit finite-difference/pseudo-spectral technique and an implementation of the Biot-Savart law. Results are presented for a Reynolds number of 200 (based on the cylinder diameter 2a and the magnitude U of the rectilinear velocity) for several values of the angular/rectilinear speed ratio alpha = (omega x a)/U (where omega is the angular speed) up to 3.25. Several aspects of the kinematics and dynamics of the flow not considered earlier are discussed. For higher values of alpha, the results indicate that for Re = 200, vortex shedding does indeed occur for alpha = 3.25. The shedding process is; however, very different from that which gives rise to the usual Karman vortex street for alpha = 0. In particular, consecutive vortices shed by the body can be shed from the same side and be of the same sense, in contrast to the nonrotating case, in which mirror-image vortices of opposite sense are shed alternately on opposite sides of the body. The implications of the results are discussed in relation to the possibility of suppressing vortex shedding by open or closed-loop control of the rotation rate.

  14. The reliability of lumbar motion palpation using continuous analysis and confidence ratings: choosing a relevant index of agreement

    PubMed Central

    Cooperstein, Robert; Young, Morgan

    2016-01-01

    Introduction: Most studies show motion palpation unreliable. This study’s primary objective was assessing its reliability using a continuous measure methods, most-fixated level paradigm, stratified by examiners’ confidence; and the secondary objective was comparing various indices of examiner agreement. Methods: Thirty-four minimally symptomatic participants were palpated in side posture by two experienced examiners. Interexaminer differences in identifying the most-fixated level and degree of examiner confidence were recorded. Indices of agreement were: Intraclass correlation coefficient, Mean and Median Examiner Absolute Examiner Differences, Root-Mean-Square Error and Bland-Altman Limits of Agreement. Results: Three of four reliability indices (excluding intraclass correlation) suggested on average examiners agreed on the most fixated motion segment, and agreement increased with confidence. Statistical measures of data dispersion were low. The analyses of subgroups were “fragile” due to small sample size. Discussion: Although subject homogeneity lowered ICC levels, the other reliability measures were not similarly impacted. Continuous measures statistical analysis demonstrates examiner agreement in situations where discrete analysis with kappa may not. Conclusion: Continuous analysis for the lumbar most-fixated level is reliable. Future studies will need a larger sample size to properly analyze subgroups based on examiner confidence. PMID:27385834

  15. A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor

    PubMed Central

    Salehizadeh, Seyed M. A.; Dao, Duy; Bolkhovsky, Jeffrey; Cho, Chae; Mendelson, Yitzhak; Chon, Ki H.

    2015-01-01

    Accurate estimation of heart rates from photoplethysmogram (PPG) signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR) estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA). The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1) training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2) test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3) Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects) is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability can be

  16. A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor.

    PubMed

    Salehizadeh, Seyed M A; Dao, Duy; Bolkhovsky, Jeffrey; Cho, Chae; Mendelson, Yitzhak; Chon, Ki H

    2015-12-23

    Accurate estimation of heart rates from photoplethysmogram (PPG) signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR) estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA). The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1) training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2) test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3) Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects) is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability can be

  17. Electromechanical actuator with controllable motion, fast response rate, and high-frequency resonance based on graphene and polydiacetylene.

    PubMed

    Liang, Jiajie; Huang, Lu; Li, Na; Huang, Yi; Wu, Yingpeng; Fang, Shaoli; Oh, Jiyoung; Kozlov, Mikhail; Ma, Yanfeng; Li, Feifei; Baughman, Ray; Chen, Yongsheng

    2012-05-22

    Although widely investigated, novel electromechanical actuators with high overall actuation performance are still in urgent need for various practical and scientific applications, such as robots, prosthetic devices, sensor switches, and sonar projectors. In this work, combining the properties of unique environmental perturbations-actuated deformational isomerization of polydiacetylene (PDA) and the outstanding intrinsic features of graphene together for the first time, we design and fabricate an electromechanical bimorph actuator composed of a layer of PDA crystal and a layer of flexible graphene paper through a simple yet versatile solution approach. Under low applied direct current (dc), the graphene-PDA bimorph actuator with strong mechanical strength can generate large actuation motion (curvature is about 0.37 cm(-1) under a current density of 0.74 A/mm(2)) and produce high actuation stress (more than 160 MPa/g under an applied dc of only 0.29 A/mm(2)). When applying alternating current (ac), this actuator can display reversible swing behavior with long cycle life under high frequencies even up to 200 Hz; significantly, while the frequency and the value of applied ac and the state of the actuators reach an appropriate value, the graphene-PDA actuator can produce a strong resonance and the swing amplitude will jump to a peak value. Moreover, this stable graphene-PDA actuator also demonstrates rapidly and partially reversible electrochromatic phenomenon when applying an ac. Two mechanisms-the dominant one, electric-induced deformation, and a secondary one, thermal-induced expansion of PDA-are proposed to contribute to these interesting actuation performances of the graphene-PDA actuators. On the basis of these results, a mini-robot with controllable direction of motion based on the graphene-PDA actuator is designed to illustrate the great potential of our discoveries for practical use. Combining the unique actuation mechanism and many outstanding properties of

  18. Rate-controlling two-proton transfer coupled with heavy-atom motion in the 2-pyridinone-catalyzed mutarotation of tetramethylglucose. Experimental and calculated deuterium isotope effects

    SciTech Connect

    Engdahl, K.A.; Bivehed, H.; Ahlberg, P.; Saunders, W.H. Jr.

    1983-07-13

    Primary and secondary deuterium isotope effects have been measured by polarimetry, and primary isotope effects have been calculated for the classical bifunctional catalysis: 2-pyridinone-catalyzed mutarotation of 2,3,4,6-tetra-O-methyl-..cap alpha..-D-glucopyranose (..cap alpha..-TMG) in benzene. From the positively curved plot of the specific rate of epimerization vs. the mole fraction of /sup 2/H in the ''pool'' of OH and NH hydrogens, the isotope effects k/sub HH//k/sub DD/ = 3.66 +/- 0.09, k/sub HH//k/sub DH/ = 1.5, and k/sub HH//k/sub HD/ = 2.4 have been calculated. A secondary isotope effect of 1.14 +/- 0.02 has been measured by using ..cap alpha..-TMG and (1-/sup 2/H)-2,3,4,6-tetra-O-methyl-..cap alpha..-D-glucopyranose ((l-/sup 2/H)-..cap alpha..-TMG), the synthesis of which is described in detail, together with those for (N-/sup 2/H)-2-pyridinone and (1-O-/sup 2/H)-2,3,4,6-tetra-O-methyl-..cap alpha..-D-glucopyranose ((1-O-/sup 2/H)-..cap alpha..-TMG). The rate data obtained have also been analyzed by fractionation theory, yielding approximately equal fractionation factors (0.5). The interpretation of the results has been assisted by calculations of the primary deuterium isotope effects using the BEBOVIB IV program. Two models involving small and considerable coupling, respectively, of the transferring protons to heavy-atom motion have been considered. In the favored structure for the transition state of the rate-limiting step, two protons are in transit, and their motion is governed either by a potential with a barrier or by one without. Their motion is considerably coupled to the heavy-atom motion (i.e., the breakage of the ring C-O bond), and tunnel corrections to the isotope effects are found to be negligible.

  19. Balance Maintenance in High-Speed Motion of Humanoid Robot Arm-Based on the 6D Constraints of Momentum Change Rate

    PubMed Central

    Zhang, Da-song; Chu, Jian

    2014-01-01

    Based on the 6D constraints of momentum change rate (CMCR), this paper puts forward a real-time and full balance maintenance method for the humanoid robot during high-speed movement of its 7-DOF arm. First, the total momentum formula for the robot's two arms is given and the momentum change rate is defined by the time derivative of the total momentum. The author also illustrates the idea of full balance maintenance and analyzes the physical meaning of 6D CMCR and its fundamental relation to full balance maintenance. Moreover, discretization and optimization solution of CMCR has been provided with the motion constraint of the auxiliary arm's joint, and the solving algorithm is optimized. The simulation results have shown the validity and generality of the proposed method on the full balance maintenance in the 6 DOFs of the robot body under 6D CMCR. This method ensures 6D dynamics balance performance and increases abundant ZMP stability margin. The resulting motion of the auxiliary arm has large abundance in joint space, and the angular velocity and the angular acceleration of these joints lie within the predefined limits. The proposed algorithm also has good real-time performance. PMID:24883404

  20. A method to characterize in vivo tendon force-strain relationship by combining ultrasonography, motion capture and loading rates.

    PubMed

    Gerus, Pauline; Rao, Guillaume; Berton, Eric

    2011-08-11

    The ultrasonography contributes to investigate in vivo tendon force-strain relationship during isometric contraction. In previous studies, different methods are available to estimate the tendon strain, using different loading rates and models to fit the tendon force-strain relationship. This study was aimed to propose a standard method to characterize the in vivo tendon force-strain relationship. We investigated the influence on the force-strain relationship for medialis gastrocnemius (MG) of (1) one method which takes into account probe and joint movements to estimate the instantaneous tendon length, (2) models used to fit the force-strain relationship for uniaxial test (polynomial vs. Ogden), and (3) the loading rate on tendon strain. Subjects performed ramp-up contraction during isometric contractions at two different target speeds: 1.5s and minimal time with ultrasound probe fixed over the muscle-tendon junction of the MG muscle. The used method requires three markers on ultrasound probe and a marker on calcaneum to take into account all movements, and was compared to the strain estimated using ultrasound images only. The method using ultrasound image only overestimated the tendon strain from 40% of maximal force. The polynomial model showed similar fitting results than the Ogden model (R²=0.98). A loading rate effect was found on tendon strain, showing a higher strain when loading rate decreases. The characterization of tendon force-strain relationship needs to be standardized by taking into account all movements to estimate tendon strain and controlling the loading rate. The polynomial model appears to be appropriate to represent the tendon force-strain relationship.

  1. High-rate precise point positioning (PPP) to measure seismic wave motions: An experimental comparison of GPS PPP with inertial measurement units

    NASA Astrophysics Data System (ADS)

    Xu, Peiliang; Shi, Chuang; Fang, Rongxin; Liu, Jingnan; Niu, Xiaoji; Zhang, Quan; Yanagidani, Takashi

    2013-04-01

    High-rate GPS has been widely used to construct displacement waveforms and to invert for source parameters of earthquakes. Almost all works on internal and external evaluation of high-rate GPS accuracy are based on GPS relative positioning. We build an experimental platform to externally evaluate the accuracy of 50 Hz PPP displacement waveforms. Since the shake table allows motion in any of six degrees of freedom, we install an inertial measurement unit (IMU) to measure the attitude of the platform and transform the IMU displacements into the GPS coordinate system. The experimental results have shown that high-rate PPP can produce absolute horizontal displacement waveforms at the accuracy of 2 to 4 millimeters and absolute vertical displacement waveforms at the sub-centimeter level of accuracy within a short period of time. The significance of the experiments indicates that high-rate PPP is capable of detecting absolute seismic displacement waveforms at the same high accuracy as GPS relative positioning techniques but requires no fixed datum station. We have also found a small scaling error of IMU and a small time offset of misalignment between high-rate PPP and IMU displacement waveforms by comparing the amplitudes of and cross-correlating both the displacement waveforms. For more details on this talk, one can now get access to the on-line-first version of our Journal of Geodesy paper: J Geod, DOI 10.1007/s00190-012-0606-z

  2. GPS and InSAR constraints on vertical tectonic motion improve the estimate of slip rate of the San Andreas Fault in southern California

    NASA Astrophysics Data System (ADS)

    Hammond, William; Johnson, Kaj; Blewitt, Geoff; Kreemer, Corné; Weldon, Ray; Burgette, Reed

    2014-05-01

    The San Andreas fault (SAF) is the fastest slipping member of a complex plate boundary system that poses a looming earthquake hazard to millions of people in southern California. Seismic hazard analysis products rely on accurate estimates of fault slip rate in order to best forecast the shaking from future damaging earthquakes. Data from geodetic GPS networks such as the EarthScope Plate Boundary Observatory, SCIGN, and other municipal networks place strong constraints on faults slip rates. However, models based geodetic measurements in the eastern Transverse Ranges suffer from uncertainties in fault dip, slip history, and viscoelastic Earth structure. Part of the problem is that data are commonly limited to horizontal interseismic rates of motion at GPS stations. Here we present results of integrated analysis of GPS and space-based InSAR data that together provide a high-resolution three-component estimation of the interseismic velocity field around the SAF. Aligning the InSAR to GPS mitigates long wavelength errors in InSAR while increasing the density of measurements between geographically sparse GPS stations. We use solutions from our GPS mega-network analysis of over 12,000 globally distributed stations processed using the GIPSY-OASIS software. Solutions are aligned to our new North America fixed reference frame (NA12), which provides strong vertical reference to compare rates across the plate boundary. Vertical data are considered if the station has at least 4 years of data, have time series that are fit well by a linear plus seasonal terms plus steps from known equipment changes and earthquakes. We use over 750 ERS and ENVISAT radar scenes from between 1992 and 2009 obtained from the WinSAR archive, including 4 frames from 5 tracks to form over 10,000 interferograms, providing line-of-sight (LOS) velocities for overlapping domains. To separate the contributions from vertical and horizontal signals, we align the InSAR LOS rates to the GPS LOS rates and

  3. STRONG EROSION-DRIVEN NONGRAVITATIONAL EFFECTS IN ORBITAL MOTIONS OF THE KREUTZ SUNGRAZING SYSTEM’S DWARF COMETS

    SciTech Connect

    Sekanina, Zdenek; Kracht, Rainer E-mail: R.Kracht@t-online.de

    2015-03-10

    We investigate the relationships among the angular orbital elements—the longitude of the ascending node Ω, the inclination i, and the argument of perihelion ω—of the Kreutz system’s faint, dwarf sungrazers observed only with the Solar and Heliospheric Observatory/STEREO coronagraphs; their published orbits were derived using a parabolic, purely gravitational approximation. In a plot of i against Ω the bright Kreutz sungrazers (such as C/1843 D1, C/1882 R1, C/1963 R1, etc.) fit a curve of fixed apsidal orientation, whereas the dwarf members are distributed along a curve that makes with the apsidal curve an angle of 15°. The dwarf sungrazers’ perihelion longitude is statistically invariable, but their perihelion latitude increases systematically with Ω. We find that this trend can be explained by a strong erosion-driven nongravitational acceleration normal to the orbit plane, confirmed for several test dwarf Kreutz sungrazers by orbital solutions with nongravitational terms incorporated directly in the equations of motion on a condition of fixed apsidal orientation. Proceeding in three steps, we first apply Marsden et al.'s standard formalism, solving for the normal acceleration only, and eventually relax additional constraints on the nongravitational law and the acceleration’s radial and transverse components. The resulting nongravitational accelerations on the dwarf sungrazers exceed the maximum for cataloged comets in nearly parabolic orbits by up to three orders of magnitude, topping in exceptional cases the Sun’s gravitational acceleration! A mass-loss model suggests that the dwarf sungrazers’ nuclei fragment copiously and their dimensions diminish rapidly near the Sun, implying the objects’ imminent demise shortly before they reach perihelion.

  4. Strong Erosion-Driven Nongravitational Effects in Orbital Motions of the Kreutz Sungrazing System’s Dwarf Comets

    NASA Astrophysics Data System (ADS)

    Sekanina, Zdenek; Kracht, Rainer

    2015-03-01

    We investigate the relationships among the angular orbital elements—the longitude of the ascending node Ω, the inclination i, and the argument of perihelion ω—of the Kreutz system’s faint, dwarf sungrazers observed only with the Solar and Heliospheric Observatory/STEREO coronagraphs; their published orbits were derived using a parabolic, purely gravitational approximation. In a plot of i against Ω the bright Kreutz sungrazers (such as C/1843 D1, C/1882 R1, C/1963 R1, etc.) fit a curve of fixed apsidal orientation, whereas the dwarf members are distributed along a curve that makes with the apsidal curve an angle of 15°. The dwarf sungrazers’ perihelion longitude is statistically invariable, but their perihelion latitude increases systematically with Ω. We find that this trend can be explained by a strong erosion-driven nongravitational acceleration normal to the orbit plane, confirmed for several test dwarf Kreutz sungrazers by orbital solutions with nongravitational terms incorporated directly in the equations of motion on a condition of fixed apsidal orientation. Proceeding in three steps, we first apply Marsden et al.'s standard formalism, solving for the normal acceleration only, and eventually relax additional constraints on the nongravitational law and the acceleration’s radial and transverse components. The resulting nongravitational accelerations on the dwarf sungrazers exceed the maximum for cataloged comets in nearly parabolic orbits by up to three orders of magnitude, topping in exceptional cases the Sun’s gravitational acceleration! A mass-loss model suggests that the dwarf sungrazers’ nuclei fragment copiously and their dimensions diminish rapidly near the Sun, implying the objects’ imminent demise shortly before they reach perihelion.

  5. The Effect of Recovery Duration on Vastus Lateralis Oxygenation, Heart Rate, Perceived Exertion and Time Motion Descriptors during Small Sided Football Games

    PubMed Central

    McLean, Scott; Kerhervé, Hugo; Lovell, Geoff P.; Gorman, Adam D.; Solomon, Colin

    2016-01-01

    Purpose Small sided games (SSG) of football are an effective and efficient format to simultaneously train the physiological, technical, and tactical components of football. The duration of the recovery period between bouts of SSG will affect the physiological response to subsequent bouts. It was hypothesised that decreasing the duration of recovery periods separating serial SSG bouts would increase physiological, and perceptual responses, and decrease high speed running, and distance during SSG bouts. Methods Twelve experienced footballers (mean ± SD; age 21 ± 3 yrs; VO2peak 64 ± 7 ml·min·kg−1; playing experience 15 ± 3 yrs) completed two SSG sessions. Each SSG consisted of 3 vs. 3 players and 6 bouts of 2 min duration, with bouts separated by either 30 s recovery (REC-30) or 120 s recovery (REC-120). Deoxygenated haemoglobin (HHb) in the vastus lateralis (VL) (using near infrared spectroscopy), heart rate (HR) and time motion descriptors (TMD) (speed and distance) were measured continuously during the SSG sessions and perceived exertion (RPE) was measured for each bout. Results During the recovery periods, in REC-30 compared to REC-120, there was a significant (p < 0.05) main effect of a higher HHb and HR. During the bouts, in REC-30 compared to REC-120, there were no significant differences in HHb, HR, RPE, or TMD, but within both REC-30 and REC-120 there were significant increases as a function of bout number in RPE. Conclusions Although a four-fold increase in recovery period allowed a significant increase in the recovery of HHb and HR, this did not increase the physiological, and perceptual responses, or time motion descriptors during the bouts. These results could have been due to the regulation of effort (pacing), in these experienced players performing an exercise task to which they were well adapted. PMID:26919064

  6. Real-time transmission of full-motion echocardiography over a high-speed data network: impact of data rate and network quality of service

    NASA Technical Reports Server (NTRS)

    Main, M. L.; Foltz, D.; Firstenberg, M. S.; Bobinsky, E.; Bailey, D.; Frantz, B.; Pleva, D.; Baldizzi, M.; Meyers, D. P.; Jones, K.; Spence, M. C.; Freeman, K.; Morehead, A.; Thomas, J. D.

    2000-01-01

    With high-resolution network transmission required for telemedicine, education, and guided-image acquisition, the impact of errors and transmission rates on image quality needs evaluation. METHODS: We transmitted clinical echocardiograms from 2 National Aeronautics and Space Administration (NASA) research centers with the use of Motion Picture Expert Group-2 (MPEG-2) encoding and asynchronous transmission mode (ATM) network protocol over the NASA Research and Education Network. Data rates and network quality (cell losses [CLR], errors [CER], and delay variability [CVD]) were altered and image quality was judged. RESULTS: At speeds of 3 to 5 megabits per second (Mbps), digital images were superior to those on videotape; at 2 Mbps, images were equivalent. Increasing CLR caused occasional, brief pauses. Extreme CER and CDV increases still yielded high-quality images. CONCLUSIONS: Real-time echocardiographic acquisition, guidance, and transmission is feasible with the use of MPEG-2 and ATM with broadcast quality seen above 3 Mbps, even with severe network quality degradation. These techniques can be applied to telemedicine and used for planned echocardiography aboard the International Space Station.

  7. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  8. Investigating source directivity for the 2012 Ml5.9 Emilia (Northern Italy) earthquake by jointly using High-rate GPS and Strong motion data

    NASA Astrophysics Data System (ADS)

    Avallone, A.; Herrero, A.; Latorre, D.; Rovelli, A.; D'Anastasio, E.

    2012-12-01

    On May, 20th 2012, the Ferrara and Modena provinces (Emilia Romagna, Northern Italy) were struck by a moderate magnitude earthquake (Ml 5.9). The focal mechanism is consistent with a ~E-W-striking thrust fault. The mainshock was recorded by 29 high-rate sampling (1-Hz) continuous GPS (HRGPS) stations belonging to scientific or commercial networks and by 55 strong motion (SM) stations belonging to INGV (Istituto Nazionale di Geofisica e Vulcanologia) and RAN (Rete Accelerometrica Nazionale) networks, respectively. The spatial distribution of both HRGPS and SM stations with respect to the mainshock location allows a satisfactory azimuthal coverage of the area. To investigate directivity effects during the mainshock occurrence, we analyze the spatial variation of the peak ground displacement (PGD) measured either for HRGPS or SM sites, using different methods. For each HRGPS and SM site, we rotated the horizontal time series to the azimuth direction and we estimated the GPS-related and the SM-related peak ground displacement (G-PGD and S-PGD, respectively) retrieved by transverse component. However, in contrast to GPS displacements, the double integration of the SM data can be affected by the presence of drifts and, thus, they have to be corrected by quasi-manual procedures. To more properly compare the G-PGDs to the S-PGDs, we used the response spectrum. A response spectrum is simply the response of a series of oscillators of varying natural frequency, that are forced into motion by the same input. The asymptotic value of the displacement response spectrum is the peak ground displacement. Thus, for each HRGPS and SM site, we computed the value of this asymptotic trend (G-PGDrs and S-PGDrs, respectively). This method allows simple automatic procedures. The consistency of the PGDs derived from HRGPS and SM is also evaluated for sites where the two instruments are collocated. The PGDs obtained by the two different methods and the two different data types suggest a

  9. Brownian motion

    NASA Astrophysics Data System (ADS)

    Lavenda, B. H.

    1985-02-01

    Brownian motion, the doubly random motion of small particles suspended in a liquid due to molecular collisions, and its implications and applications in the history of modern science are discussed. Topics examined include probabilistic phenomena, the kinetic theory of gases, Einstein's atomic theory of Brownian motion, particle displacement, diffusion measurements, the determination of the mass of the atom and of Avogadro's number, the statistical mechanics of thermodynamics, nonequilibrium systems, Langevin's equation of motion, time-reversed evolution, mathematical analogies, and applications in economics and radio navigation. Diagrams and drawings are provided.

  10. NMR relaxation rate studies of molecular motions in NaSn, the Laves-phase metal hydride C15-ZrCr(2)H(x) and carbon/epoxy composite materials

    NASA Astrophysics Data System (ADS)

    Stoddard, Ronald Dean

    Here I present studies of molecular motions in three very different systems: NaSn, which exhibits motion characteristic of both a superionic conductor and a rotor crystal; C15-ZrCrsb2Hsbx (x < 0.5), a metal hydride which exhibits unusual characteristics in its hydrogen motion; and, finally a study of the relationship between Tsb2 and the degree of cure of carbon/epoxy materials. NaSn is characterized by Nasp+ ions and stable (Snsb4)sp{4-} tetrahedra. At high temperatures NaSn displays a disordered solid phase (alpha-NaSn). The presence of Nasp+ ions suggests that alpha-NaSn may be a superionic conductor (translationally disordered) and the presence of stable Snsb4 tetrahedra suggests it may be a rotor crystal (organizationally disordered). The purpose of this study is to gain better understanding of the motions in alpha-NaSn by monitoring Na and Sn motion using sp{23}Na and sp{119}Sn NMR, respectively. C15-ZrCrsb2Hsbx (x < 0.5) is a Laves phase metal hydride which displays extremely rapid hydrogen motion and a Tsb1 peak which cannot be explained by a model employing a single correlation time for the motion. A model employing a Gaussian distribution of correlation times has been used to successfully fit Tsb1, but the origin of this distribution in a crystalline solid solution is not known. The purpose of this study is to better understand the low temperature hydrogen motions occurring in C15-ZrCrsb2Hsbx by extending the previous NMR measurements using Tsb1p and Tsb1D, experiments which effectively push the relaxation peak to lower temperatures. New techniques for manufacturing carbon/epoxy components are under development which require partial curing of the material. At present, no method for monitoring partial curing exists. Tsb2 is a promising monitor of degree of cure because of its sensitivity to changes rates of molecular motions. The purpose of this study is to demonstrate the sensitivity of Tsb2 to changes in molecular motion due to curing, and to find a

  11. Circular Motion.

    ERIC Educational Resources Information Center

    Lee, Paul D.

    1995-01-01

    Provides a period-long activity using battery powered cars rolling in a circular motion on a tile floor. Students measure the time and distance as the car moves to derive the equation for centripetal acceleration. (MVL)

  12. Brownian Motion.

    ERIC Educational Resources Information Center

    Lavenda, Bernard H.

    1985-01-01

    Explains the phenomenon of Brownian motion, which serves as a mathematical model for random processes. Topics addressed include kinetic theory, Einstein's theory, particle displacement, and others. Points out that observations of the random course of a particle suspended in fluid led to the first accurate measurement of atomic mass. (DH)

  13. Motion Sickness

    MedlinePlus

    ... but it is more common in children, pregnant women, and people taking certain medicines. Motion sickness can start suddenly, with a queasy feeling and cold sweats. It can then lead to dizziness and nausea and vomiting. Your brain senses movement by getting signals from your inner ears, eyes, ...

  14. Dislocation motion and instability

    NASA Astrophysics Data System (ADS)

    Zhu, Yichao; Chapman, Stephen Jonathan; Acharya, Amit

    2013-08-01

    The Peach-Koehler expression for the stress generated by a single (non-planar) curvilinear dislocation is evaluated to calculate the dislocation self stress. This is combined with a law of motion to give the self-induced motion of a general dislocation curve. A stability analysis of a rectilinear, uniformly translating dislocation is then performed. The dislocation is found to be susceptible to a helical instability, with the maximum growth rate occurring when the dislocation is almost, but not exactly, pure screw. The non-linear evolution of the instability is determined numerically, and implications for slip band formation and non-Schmid behavior in yielding are discussed.

  15. [Motion sickness].

    PubMed

    Taillemite, J P; Devaulx, P; Bousquet, F

    1997-01-01

    Motion sickness is a general term covering sea-sickness, car-sickness, air-sickness, and space-sickness. Symptoms can occur when a person is exposed to unfamiliar movement whether real or simulated. Despite progress in the technology and comfort of modern transportation (planes, boats, and overland vehicles), a great number of travelers still experience motion sickness. Bouts are characterized by an initial phase of mild discomfort followed by neurologic and gastro-intestinal manifestations. The delay in onset depends on specific circumstances and individual susceptibility. Attacks are precipitated by conflicting sensory, visual, and vestibular signals but the underlying mechanism is unclear. Most medications used for prevention and treatment (e.g. anticholinergics and antihistamines) induce unwanted sedation. Furthermore no one drug is completely effective or preventive under all conditions.

  16. Chaos in navigation satellite orbits caused by the perturbed motion of the Moon

    NASA Astrophysics Data System (ADS)

    Rosengren, Aaron J.; Alessi, Elisa Maria; Rossi, Alessandro; Valsecchi, Giovanni B.

    2015-06-01

    Numerical simulations carried out over the past decade suggest that the orbits of the Global Navigation Satellite Systems are unstable, resulting in an apparent chaotic growth of the eccentricity. Here, we show that the irregular and haphazard character of these orbits reflects a similar irregularity in the orbits of many celestial bodies in our Solar system. We find that secular resonances, involving linear combinations of the frequencies of nodal and apsidal precession and the rate of regression of lunar nodes, occur in profusion so that the phase space is threaded by a devious stochastic web. As in all cases in the Solar system, chaos ensues where resonances overlap. These results may be significant for the analysis of disposal strategies for the four constellations in this precarious region of space.

  17. Seismic Sources and Recurrence Rates as Adopted by USGS Staff for the Production of the 1982 and 1990 Probabilistic Ground Motion Maps for Alaska and the Conterminous United States

    USGS Publications Warehouse

    Hanson, Stanley L.; Perkins, David M.

    1995-01-01

    The construction of a probabilistic ground-motion hazard map for a region follows a sequence of analyses beginning with the selection of an earthquake catalog and ending with the mapping of calculated probabilistic ground-motion values (Hanson and others, 1992). An integral part of this process is the creation of sources used for the calculation of earthquake recurrence rates and ground motions. These sources consist of areas and lines that are representative of geologic or tectonic features and faults. After the design of the sources, it is necessary to arrange the coordinate points in a particular order compatible with the input format for the SEISRISK-III program (Bender and Perkins, 1987). Source zones are usually modeled as a point-rupture source. Where applicable, linear rupture sources are modeled with articulated lines, representing known faults, or a field of parallel lines, representing a generalized distribution of hypothetical faults. Based on the distribution of earthquakes throughout the individual source zones (or a collection of several sources), earthquake recurrence rates are computed for each of the sources, and a minimum and maximum magnitude is assigned. Over a period of time from 1978 to 1980 several conferences were held by the USGS to solicit information on regions of the United States for the purpose of creating source zones for computation of probabilistic ground motions (Thenhaus, 1983). As a result of these regional meetings and previous work in the Pacific Northwest, (Perkins and others, 1980), California continental shelf, (Thenhaus and others, 1980), and the Eastern outer continental shelf, (Perkins and others, 1979) a consensus set of source zones was agreed upon and subsequently used to produce a national ground motion hazard map for the United States (Algermissen and others, 1982). In this report and on the accompanying disk we provide a complete list of source areas and line sources as used for the 1982 and later 1990 seismic

  18. Space motion sickness

    NASA Technical Reports Server (NTRS)

    Homick, J. L.

    1979-01-01

    Research on the etiology, prediction, treatment and prevention of space motion sickness, designed to minimize the impact of this syndrome which was experienced frequently and with severity by individuals on the Skylab missions, on Space Shuttle crews is reviewed. Theories of the cause of space motion sickness currently under investigation by NASA include sensory conflict, which argues that motion sickness symptoms result from a mismatch between the total pattern of information from the spatial senses and that stored from previous experiences, and fluid shift, based upon the redistribution of bodily fluids that occurs upon continued exposure to weightlessness. Attempts are underway to correlate space motion sickness susceptibility to different provocative environments, vestibular and nonvestibular responses, and the rate of acquisition and length of retention of sensory adaptation. Space motion sickness countermeasures under investigation include various drug combinations, of which the equal combination of promethazine and ephedrine has been found to be as effective as the scopolomine and dexedrine combination, and vestibular adaptation and biofeedback training and autogenic therapy.

  19. Muon motion in titanium hydride

    NASA Technical Reports Server (NTRS)

    Kempton, J. R.; Petzinger, K. G.; Kossler, W. J.; Schone, H. E.; Hitti, B. S.; Stronach, C. E.; Adu, N.; Lankford, W. F.; Reilly, J. J.; Seymour, E. F. W.

    1988-01-01

    Motional narrowing of the transverse-field muon spin rotation signal was observed in gamma-TiH(x) for x = 1.83, 1.97, and 1.99. An analysis of the data for TiH1.99 near room temperature indicates that the mechanism responsible for the motion of the muon out of the octahedral site is thermally activated diffusion with an attempt frequency comparable to the optical vibrations of the lattice. Monte Carlo calculations to simulate the effect of muon and proton motion upon the muon field-correlation time were used to interpret the motional narrowing in TiH1.97 near 500 K. The interpretation is dependent upon whether the Bloembergen, Purcell, and Pound (BPP) theory or an independent spin-pair relaxation model is used to obtain the vacancy jump rate from proton NMR T1 measurements. Use of BPP theory shows that the field-correction time can be obtained if the rate of motion of the muon with respect to the rate of the motion for the protons is decreased. An independent spin-pair relaxation model indicates that the field-correlation time can be obtained if the rate of motion for the nearest-neighbor protons is decreased.

  20. Objective Motion Cueing Criteria Investigation Based on Three Flight Tasks

    NASA Technical Reports Server (NTRS)

    Zaal, Petrus M. T.; Schroeder, Jeffery A.; Chung, William W.

    2015-01-01

    This paper intends to help establish fidelity criteria to accompany the simulator motion system diagnostic test specified by the International Civil Aviation Organization. Twelve air- line transport pilots flew three tasks in the NASA Vertical Motion Simulator under four different motion conditions. The experiment used three different hexapod motion configurations, each with a different tradeoff between motion filter gain and break frequency, and one large motion configuration that utilized as much of the simulator's motion space as possible. The motion condition significantly affected: 1) pilot motion fidelity ratings, and sink rate and lateral deviation at touchdown for the approach and landing task, 2) pilot motion fidelity ratings, roll deviations, maximum pitch rate, and number of stick shaker activations in the stall task, and 3) heading deviation after an engine failure in the takeoff task. Significant differences in pilot-vehicle performance were used to define initial objective motion cueing criteria boundaries. These initial fidelity boundaries show promise but need refinement.

  1. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    ERIC Educational Resources Information Center

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

  2. Motion-Matching: A Challenge Game to Generate Motion Concepts

    NASA Astrophysics Data System (ADS)

    Schuster, David; Adams, Betty; Brookes, David; Milner-Bolotin, Marina; Undreiu, Adriana

    2009-10-01

    Motion is a topic that is taught from elementary grades through to university at various levels of sophistication. It is an area that can be challenging for learning in a conceptually meaningful way, and formal kinematics instruction can sometimes seem dry and boring. Thus, the nature of students' initial introduction to motion is important in sparking their interest, shaping their perspective, and developing conceptual understanding of motion. The kinematic concepts we want students to acquire for basic motions are: position, time, speed, direction, velocity, velocity change, change rate, and acceleration, all with respect to a frame of reference. In this article we describe a challenge game used as an "opener" to motion, in which students themselves essentially generate these concepts, in everyday language, from a perceived need for them.

  3. Decadal variations in geophysical processes and asymmetries in the solar motion about the Solar System's barycentre

    NASA Astrophysics Data System (ADS)

    Sidorenkov, Nikolay; Wilson, Ian; Khlystov, Anatoly

    2010-05-01

    Motion (SIM). Over the last 800 years, the Earth has experience exceptionally strong tidal forces in the years 1247, 1433, 1610, 1787 and 1974 (Keeling and Whorf, 1997). He shows that these exceptionally strong tidal forces closely correspond in time to the first peak in the asymmetry of the SIM that occurs just after a period low asymmetry. These first peaks in asymmetry in the SIM occur in the years 1251, 1432, 1611, 1791, and 1971, closely correspond the years of peak tidal force. Thus, there appear to be periodic alignments between the lunar apsides, syzygies and lunar nodes that occur at almost exactly the same times that the SIM becomes most asymmetric for the first time after a period of low asymmetry in the SIM. It means that precession and stretching of the Lunar orbit (i.e. the factors that control the long-term variation of the lunar tides that are experienced here on Earth) are almost perfectly synchronized with the SIM. If the Solar system just consisted of Jupiter and the Sun, the barycentre of the Solar System would move in an almost circular orbit located just above the surface of the Sun (i.e. about 1.08 solar radii), called the sub-Jupiter point. Hence, the actual motion of the barycentre about the centre of the Sun (or equivalently the Sun about the barycentre) can be considered as a combination of the smooth symmetrical motion produced by Jupiter, combined with an additional, often asymmetric motion, caused by the other three Jovan planets (principally, Saturn and Neptune). The distance of the centre-of-mass from the Sub-Jupiter point is an excellent indicator of the level of asymmetry of the Sun's orbital motion, at any given time. A.I.Khlystov et al., (1992,1995) showed that the Earth and the other planets move in ellipses with the Sun at one foci, while at the same time they (effectively) share in the motion of the Sun around barycenter of the solar system. From the above results two important conclusions follows: 1) The movement of each planet is

  4. Motion Simulator

    NASA Technical Reports Server (NTRS)

    1993-01-01

    MOOG, Inc. supplies hydraulic actuators for the Space Shuttle. When MOOG learned NASA was interested in electric actuators for possible future use, the company designed them with assistance from Marshall Space Flight Center. They also decided to pursue the system's commercial potential. This led to partnership with InterActive Simulation, Inc. for production of cabin flight simulators for museums, expositions, etc. The resulting products, the Magic Motion Simulator 30 Series, are the first electric powered simulators. Movements are computer-guided, including free fall to heighten the sense of moving through space. A projection system provides visual effects, and the 11 speakers of a digital laser based sound system add to the realism. The electric actuators are easier to install, have lower operating costs, noise, heat and staff requirements. The U.S. Space & Rocket Center and several other organizations have purchased the simulators.

  5. Source rupture process of the 5 September 2012 Costa Rica Mw=7.6 thrust event from joint inversion of high-rate GPS, strong motion, and teleseismic P wave data

    NASA Astrophysics Data System (ADS)

    Lay, T.; Yue, H.; Rivera, L. A.; Schwartz, S. Y.; Protti, M.

    2013-05-01

    On 5 September 2012, a large thrust event (Mw=7.6) ruptured a densely instrumented seismic gap on the shallow plate boundary beneath the Nicoya Peninsula, Costa Rica. Networks of strong motion accelerometers, broadband and short-period sensors, and high-rate (5-sps) GPS stations recorded ground motions directly above the rupture zone, providing a unique opportunity to study the detailed source process of a large shallow megathrust rupture using nearby land observations. An inland and relatively deep hypocenter (10.086°N, 85.305°W, 40 km) was estimated by the USGS, and teleseismic W-phase inversions also indicate a relatively large (30-40 km) centroid depth. Hypocenter relocation performed using the local seismic network data indicates that the event initiated with small emergent seismic waves from a hypocenter ~10 km offshore (9.80°N, 85.53°W) 15 km deep on the megathrust. The local origin time (14:42:05) is 3 s earlier than the USGS origin time, compatible with the shallower source depth. A joint finite-fault inversion of 0.2 Hz lowpass-filtered hr-GPS recordings, <0.4 Hz ground velocity recordings from regional strong-motion sensors, and teleseismic P waves reveals that the primary slip zone is located beneath the Nicoya coastline up-dip from the USGS location. Complete ground motions are computed for the hr-GPS stations using a 1D regional velocity model and a wavenumber integration program from Robert Herrmann. The large-slip region extends ~50 km along strike and ~30 km along dip, with a centroid depth of ~23 km. The maximum slip is ~4 meters and Mw=7.6, consistent with teleseismic estimates. The inversion indicates that the rupture propagated down-dip from the offshore hypocenter with a rupture velocity of ~2.5 km/s. The inversion has limited resolution of any offshore slip, but slip occurred in a region about 30 km offshore along the northern half of the rupture zone. We consider the relationship between coseismic slip location, aftershocks and adjacent

  6. Plate motion and deformation

    SciTech Connect

    Minster, B.; Prescott, W.; Royden, L.

    1991-02-01

    Our goal is to understand the motions of the plates, the deformation along their boundaries and within their interiors, and the processes that control these tectonic phenomena. In the broadest terms, we must strive to understand the relationships of regional and local deformation to flow in the upper mantle and the rheological, thermal and density structure of the lithosphere. The essential data sets which we require to reach our goal consist of maps of current strain rates at the earth's surface and the distribution of integrated deformation through time as recorded in the geologic record. Our success will depend on the effective synthesis of crustal kinematics with a variety of other geological and geophysical data, within a quantitative theoretical framework describing processes in the earth's interior. Only in this way can we relate the snapshot of current motions and earth structure provided by geodetic and geophysical data with long-term processes operating on the time scales relevant to most geological processes. The wide-spread use of space-based techniques, coupled with traditional geological and geophysical data, promises a revolution in our understanding of the kinematics and dynamics of plate motions over a broad range of spatial and temporal scales and in a variety of geologic settings. The space-based techniques that best address problems in plate motion and deformation are precise space-geodetic positioning -- on land and on the seafloor -- and satellite acquisition of detailed altimetric and remote sensing data in oceanic and continental areas. The overall science objectives for the NASA Solid Earth Science plan for the 1990's, are to Understand the motion and deformation of the lithosphere within and across plate boundaries'', and to understand the dynamics of the mantle, the structure and evolution of the lithosphere, and the landforms that result from local and regional deformation. 57 refs., 7 figs., 2 tabs.

  7. Auditory Motion Elicits a Visual Motion Aftereffect

    PubMed Central

    Berger, Christopher C.; Ehrsson, H. Henrik

    2016-01-01

    The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect—an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates. PMID:27994538

  8. Collective motion

    NASA Astrophysics Data System (ADS)

    Vicsek, Tamás; Zafeiris, Anna

    2012-08-01

    We review the observations and the basic laws describing the essential aspects of collective motion - being one of the most common and spectacular manifestation of coordinated behavior. Our aim is to provide a balanced discussion of the various facets of this highly multidisciplinary field, including experiments, mathematical methods and models for simulations, so that readers with a variety of background could get both the basics and a broader, more detailed picture of the field. The observations we report on include systems consisting of units ranging from macromolecules through metallic rods and robots to groups of animals and people. Some emphasis is put on models that are simple and realistic enough to reproduce the numerous related observations and are useful for developing concepts for a better understanding of the complexity of systems consisting of many simultaneously moving entities. As such, these models allow the establishing of a few fundamental principles of flocking. In particular, it is demonstrated, that in spite of considerable differences, a number of deep analogies exist between equilibrium statistical physics systems and those made of self-propelled (in most cases living) units. In both cases only a few well defined macroscopic/collective states occur and the transitions between these states follow a similar scenario, involving discontinuity and algebraic divergences.

  9. Submarine Landslides and Gas Hydrates: Using a Rate and State Friction Model to Describe Incipient Motion Triggered by the Dissociation of High Saturation Hydrate Anomalies

    NASA Astrophysics Data System (ADS)

    Handwerger, A. L.; Rempel, A. W.; Skarbek, R. M.

    2015-12-01

    The dissociation of gas hydrates along the continental shelf can potentially trigger submarine landslides. The hazard produced by such landslides can generate tsunamis, damage or destroy infrastructure, and result in a catastrophic release of methane to the ocean and atmosphere. Here we develop a 1D numerical model to identify the conditions under which the dissociation of gas hydrates can trigger submarine landslides. In particular we focus on high saturation hydrate anomalies (e.g., lenses and nodules) that unload the sediment particle contacts and prevent normal consolidation. These areas are of interest because upon dissociation they can generate excess pore pressure from rapid consolidation and from fluid flow due to changes in the averaged density of pore constituents. Our model tracks the evolution of pore pressure and effective stress as the hydrate anomalies decay using lab derived constitutive relationships from consolidation experiments. To quantify the potential for slope failure, we use a rate- and state-dependent frictional model adapted from standard fault mechanics treatments to assess the stability of finite slip patches subjected to these excess pore pressures. We find that submarine landslides will occur if the size of the slip patch exceeds a critical nucleation length. Thus, excess pore pressures generated by hydrate dissociation have the potential to trigger submarine landslides, if not significantly weaken the sediment such that external forces (e.g., nearby earthquakes) can trigger failure. Our results illustrate the fundamental mechanisms through which the dissociation of gas hydrates can pose a significant geohazard. Further tests using this model will help to better assess the risks of hydrate-triggered slope failure in a changing environment

  10. Human comfort response to dominant random motions in longitudinal modes of aircraft motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1980-01-01

    The effects of random vertical and longitudinal accelerations and pitching velocity passenger ride comfort responses were examined on the NASA Langley Visual Motion Simulator. Effects of power spectral density shape were studied for motions where the peak was between 0 and 2 Hz. The subjective rating data and the physical motion data obtained are presented without interpretation or detailed analysis. There existed motions in all other degrees of freedom as well as the particular pair of longitudinal airplane motions studied. These unwanted motions, caused by the characteristics of the simulator may have introduced some interactive effects on passenger responses.

  11. Self Motion Perception and Motion Sickness

    NASA Technical Reports Server (NTRS)

    Fox, Robert A. (Principal Investigator)

    1991-01-01

    The studies conducted in this research project examined several aspects of motion sickness in animal models. A principle objective of these studies was to investigate the neuroanatomy that is important in motion sickness with the objectives of examining both the utility of putative models and defining neural mechanisms that are important in motion sickness.

  12. Slow and fast motion of cracks in inelastic solids. Part 1: Slow growth of cracks in a rate sensitive tresca solid. Part 2: Dynamic crack represented by the Dugdale model

    NASA Technical Reports Server (NTRS)

    Wnuk, M. P.; Sih, G. C.

    1972-01-01

    An extension is proposed of the classical theory of fracture to viscoelastic and elastic-plastic materials in which the plasticity effects are confined to a narrow band encompassing the crack front. It is suggested that the Griffith-Irwin criterion of fracture, which requires that the energy release rate computed for a given boundary value problem equals the critical threshold, ought to be replaced by a differential equation governing the slow growth of a crack prior to the onset of rapid propagation. A new term which enters the equation of motion in the dissipative media is proportional to the energy lost within the end sections of the crack, and thus reflects the extent of inelastic behavior of a solid. A concept of apparent surface energy is introduced to account for the geometry dependent and the rate dependent phenomena which influence toughness of an inelastic solid. Three hypotheses regarding the condition for fracture in the subcritical range of load are compared. These are: (1) constant fracture energy (Cherepanov), (2) constant opening displacement at instability (Morozov) and (3) final stretch criterion (Wnuk).

  13. Dynamics of the 3/1 planetary mean-motion resonance: an application to the HD60532 b-c planetary system

    NASA Astrophysics Data System (ADS)

    Alves, A. J.; Michtchenko, T. A.; Tadeu dos Santos, M.

    2016-03-01

    In this paper, we use a semi-analytical approach to analyze the global structure of the phase space of the planar planetary 3/1 mean-motion resonance. The case where the outer planet is more massive than its inner companion is considered. We show that the resonant dynamics can be described using two fundamental parameters, the total angular momentum and the spacing parameter. The topology of the Hamiltonian function describing the resonant behaviour is investigated on a large domain of the phase space without time-expensive numerical integrations of the equations of motion, and without any restriction on the magnitude of the planetary eccentricities. The families of the Apsidal Corotation Resonances (ACR) parameterized by the planetary mass ratio are obtained and their stability is analyzed. The main dynamical features in the domains around the ACR are also investigated in detail by means of spectral analysis techniques, which allow us to detect the regions of different regimes of motion of resonant systems. The construction of dynamical maps for various values of the total angular momentum shows the evolution of domains of stable motion with the eccentricities, identifying possible configurations suitable for exoplanetary systems.

  14. Self-Motion Perception and Motion Sickness

    NASA Technical Reports Server (NTRS)

    Fox, Robert A.

    1991-01-01

    Motion sickness typically is considered a bothersome artifact of exposure to passive motion in vehicles of conveyance. This condition seldom has significant impact on the health of individuals because it is of brief duration, it usually can be prevented by simply avoiding the eliciting condition and, when the conditions that produce it are unavoidable, sickness dissipates with continued exposure. The studies conducted examined several aspects of motion sickness in animal models. A principle objective of these studies was to investigate the neuroanatomy that is important in motion sickness with the objectives of examining both the utility of putative models and defining neural mechanisms that are important in motion sickness.

  15. Theoretical motions of hydrofoil systems

    NASA Technical Reports Server (NTRS)

    Imlay, Frederick H

    1948-01-01

    Results are presented of an investigation that has been undertaken to develop theoretical methods of treating the motions of hydrofoil systems and to determine some of the important parameters. Variations of parameters include three distributions of area between the hydrofoils, two rates of change of downwash angle with angle of attack, three depths of immersion, two dihedral angles, two rates of change of lift with immersion, three longitudinal hydrofoil spacings, two radii of gyration in pitching, and various horizontal and vertical locations of the center of gravity. Graphs are presented to show locations of the center of gravity for stable motion, values of the stability roots, and motions following the sudden application of a vertical force or a pitching moment to the hydrofoil system for numerous sets of values of the parameters.

  16. Yaw Motion Cues in Helicopter Simulation

    NASA Technical Reports Server (NTRS)

    Schroeder, Jeffrey A.; Johnson, Walter W.

    1996-01-01

    A piloted simulation that examined the effects of yaw motion cues on pilot-vehicle performance, pilot workload, and pilot motion perception was conducted on the NASA Ames Vertical Motion Simulator. The vehicle model that was used represented an AH-64 helicopter. Three tasks were performed in which only combinations of vehicle yaw and vertical displacement were allowed. The commands issued to the motion platform were modified to present the following four motion configurations for a pilot located forward of the center of rotation: (1) only the linear translations, (2) only the angular rotation, (3) both the linear translations and the angular rotation, and (4) no motion. The objective data indicated that pilot-vehicle performance was reduced and the necessary control activity increased when linear motion was removed; however, the lack of angular rotation did not result in a measured degradation for almost all cases. Also, pilots provided subjective assessments of their compensation required, the motion fidelity, and their judgment of whether or not linear or rotational cockpit motion was present. Ratings of compensation and fidelity were affected only by linear acceleration, and the rotational motion had no significant impact. Also, when only linear motion was present, pilots typically reported the presence of rotation. Thus, linear acceleration cues, not yaw rotational cues, appear necessary to simulate hovering flight.

  17. Human comfort response to random motions with combined yawing and rolling motions

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1979-01-01

    The effects of random yawing and rolling velocities on passenger ride comfort responses were examined on a visual motion simulator. The effects of power spectral density shape and frequency ranges of peak power from 0 to 2 Hz were studied. The subjective rating data and the physical motion data obtained are presented. No attempt at interpretation or detailed analysis of the data is made. There existed during this study motions in all other degrees of freedom as well as the yawing and rolling motions, because of the characteristics of the simulator. These unwanted motions may have introduced some interactive effects on passenger responses which should be considered in any analysis of the data.

  18. Human comfort response to random motions with a dominant pitching motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1980-01-01

    The effects of random pitching velocities on passenger ride comfort response were examined on the NASA Langley Visual Motion Simulator. The effects of power spectral density shape and frequency ranges from 0 to 2 Hz were studied. The subjective rating data and the physical motion data obtained are presented. No attempt at interpretation or detailed analysis of the data is made. Motions in all degrees of freedom existed as well as the intended pitching motion, because of the characteristics of the simulator. These unwanted motions may have introduced some interactive effects on passenger responses which should be considered in any analysis of the data.

  19. 38 CFR 4.59 - Painful motion.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... DISABILITIES Disability Ratings The Musculoskeletal System § 4.59 Painful motion. With any form of arthritis... assist the identification. Sciatic neuritis is not uncommonly caused by arthritis of the spine....

  20. 38 CFR 4.59 - Painful motion.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DISABILITIES Disability Ratings The Musculoskeletal System § 4.59 Painful motion. With any form of arthritis... assist the identification. Sciatic neuritis is not uncommonly caused by arthritis of the spine....

  1. Helicopter flight simulation motion platform requirements

    NASA Astrophysics Data System (ADS)

    Schroeder, Jeffery Allyn

    Flight simulators attempt to reproduce in-flight pilot-vehicle behavior on the ground. This reproduction is challenging for helicopter simulators, as the pilot is often inextricably dependent on external cues for pilot-vehicle stabilization. One important simulator cue is platform motion; however, its required fidelity is unknown. To determine the required motion fidelity, several unique experiments were performed. A large displacement motion platform was used that allowed pilots to fly tasks with matched motion and visual cues. Then, the platform motion was modified to give cues varying from full motion to no motion. Several key results were found. First, lateral and vertical translational platform cues had significant effects on fidelity. Their presence improved performance and reduced pilot workload. Second, yaw and roll rotational platform cues were not as important as the translational platform cues. In particular, the yaw rotational motion platform cue did not appear at all useful in improving performance or reducing workload. Third, when the lateral translational platform cue was combined with visual yaw rotational cues, pilots believed the platform was rotating when it was not. Thus, simulator systems can be made more efficient by proper combination of platform and visual cues. Fourth, motion fidelity specifications were revised that now provide simulator users with a better prediction of motion fidelity based upon the frequency responses of their motion control laws. Fifth, vertical platform motion affected pilot estimates of steady-state altitude during altitude repositionings. This refutes the view that pilots estimate altitude and altitude rate in simulation solely from visual cues. Finally, the combined results led to a general method for configuring helicopter motion systems and for developing simulator tasks that more likely represent actual flight. The overall results can serve as a guide to future simulator designers and to today's operators.

  2. Comparative orbital evolution of transient Uranian co-orbitals: exploring the role of ephemeral multibody mean motion resonances

    NASA Astrophysics Data System (ADS)

    de la Fuente Marcos, C.; de la Fuente Marcos, R.

    2014-07-01

    Uranus has three known co-orbitals: 83982 Crantor (2002 GO9), 2010 EU65 and 2011 QF99. All of them were captured in their current resonant state relatively recently. Here, we perform a comparative analysis of the orbital evolution of these transient co-orbitals to understand better how they got captured in the first place and what makes them dynamically unstable. We also look for additional temporary Uranian co-orbital candidates among known objects. Our N-body simulations show that the long-term stability of 2011 QF99 is controlled by Jupiter and Neptune; it briefly enters the 1:7 mean motion resonance with Jupiter and the 2:1 with Neptune before becoming a Trojan and prior to leaving its tadpole orbit. During these ephemeral two-body mean motion resonance episodes, apsidal corotation resonances are also observed. For known co-orbitals, Saturn is the current source of the main destabilizing force but this is not enough to eject a minor body from the 1:1 commensurability with Uranus. These objects must enter mean motion resonances with Jupiter and Neptune in order to be captured or become passing Centaurs. Asteroid 2010 EU65, a probable visitor from the Oort cloud, may have been stable for several Myr due to its comparatively low eccentricity. Additionally, we propose 2002 VG131 as the first transient quasi-satellite candidate of Uranus. Asteroid 1999 HD12 may signal the edge of Uranus' co-orbital region. Transient Uranian co-orbitals are often submitted to complex multibody ephemeral mean motion resonances that trigger the switching between resonant co-orbital states, making them dynamically unstable. In addition, we show that the orbital properties and discovery circumstances of known objects can be used to outline a practical strategy by which additional Uranus' co-orbitals may be found.

  3. Objects in Motion

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    One thing scientists study is how objects move. A famous scientist named Sir Isaac Newton (1642-1727) spent a lot of time observing objects in motion and came up with three laws that describe how things move. This explanation only deals with the first of his three laws of motion. Newton's First Law of Motion says that moving objects will continue…

  4. General autonomic components of motion sickness

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia S.; Suter, Steve; Toscano, William B.; Kamiya, Joe; Naifeh, Karen

    1986-01-01

    This report refers to a body of investigations directed toward the examination of autonomic nervous system responses to motion sickness. Heart rate, respiration rate, finger pulse volume, and basal skin resistance were measured on 127 men and women before, during, and after exposure to a nauseogenic rotating chair test. Significant changes in all autonomic responses were observed across the tests (p less than .05). Significant differences in autonomic responses among groups divided according to motion sickness susceptibility were also observed (p less than .05). Results suggest that the examination of autonomic responses as an objective indicator of motion sickness malaise is warranted and may contribute to the overall understanding of the syndrome.

  5. Dual motion valve with single motion input

    NASA Technical Reports Server (NTRS)

    Belew, Robert (Inventor)

    1987-01-01

    A dual motion valve includes two dual motion valve assemblies with a rotary input which allows the benefits of applying both rotary and axial motion to a rotary sealing element with a plurality of ports. The motion of the rotary sealing element during actuation provides axial engagement of the rotary sealing element with a stationary valve plate which also has ports. Fluid passages are created through the valve when the ports of the rotary sealing element are aligned with the ports of the stationary valve plate. Alignment is achieved through rotation of the rotary sealing element with respect to the stationary valve plate. The fluid passages provide direct paths which minimize fluid turbulence created in the fluid as it passes through the valve.

  6. 29 CFR 541.709 - Motion picture producing industry.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Motion picture producing industry. 541.709 Section 541.709... SALES EMPLOYEES Definitions and Miscellaneous Provisions § 541.709 Motion picture producing industry... motion picture producing industry who is compensated at a base rate of at least $695 a week (exclusive...

  7. The Eclipsing Binary Di Herculis: One Mystery Solved, But Another Takes Its Place

    NASA Astrophysics Data System (ADS)

    Zimmerman, Nicole; Guinan, E.; Maloney, F.

    2010-01-01

    The 8th-mag eclipsing binary DI Herculis has perplexed scientists for the past few decades due to its anomalously slow apsidal motion rate. DI Her consists of two main-sequence stars (B5V, B6V), with P(orb) = 10.55 days, and eccentricity(e= 0.489). Since the apsidal motion is dominated by General Relativity, the system is one of the few tests available for verifying the theory. Combining the expected classical (1.93°/100 yr) and relativistic (2.34°/100 yr) effects, the predicted apsidal motion rate is 4.27°/100 yr. Our recent determination of the apsidal motion yields 1.33°+/-0.25 /100 yr, based on eclipse timings from 1936-2008. Recently, Albrecht et al (2009, Nature 461) have apparently solved the apsidal motion anomaly of DI Her, finding that the axes of both stars are significantly inclined from the normal to the orbital plane. This was determined from the radial velocity curves and observing the Rossiter-McLaughlin effect during primary and secondary eclipses. Having significantly misaligned axes of rotation produces a perturbation that greatly reduces the classical apsidal motion effect, thus explaining the observed small apsidal motion rate. Even though this discovery apparently solves the problem, it raises new questions as to how the axes are so tilted. Additionally, tilted axes are expected to contribute to other orbital effects, such as changes in orbital inclination, which have not yet observed from the apparent constancy in eclipse depths over time. We have also searched for evidence of small periodic oscillations in the eclipse timings and found no evidence of a light travel time effect arising from a possible tertiary component. Further, we find evidence that the projected rotation axes of the stars may be precessing, since it appears that the value of V(rot)sini has increased over the past 30 years. This research was supported by NSF/RUI Grants AST05-07536/42.

  8. Conditional replenishment using motion prediction

    NASA Technical Reports Server (NTRS)

    Hein, D. N.; Jones, H. W., Jr.

    1979-01-01

    Conditional replenishment is an interframe video compression method that uses correlation in time to reduce video transmission rates. This method works by detecting and sending only the changing portions of the image and by having the receiver use the video data from the previous frame for the non-changing portion. The amount of compression that can be achieved through this technique depends to a large extent on the rate of change within the image, and can vary from 10 to 1 to less than 2 to 1. An additional 3 to 1 reduction in rate is obtained by the intraframe coding of data blocks using a 2-dimensional variable rate Hadamard transform coder. A further additional 2 to 1 rate reduction is achieved by using motion prediction. Motion prediction works by measuring the relative displacements of a subpicture from one frame to the next. The subpicture can then be transmitted by sending only the value of the 2-dimensional displacement. Computer simulations have demonstrated that data rates of 2 to 4 Mega-bits/second can be achieved while still retaining good fidelity in the image.

  9. Motion through syntactic frames.

    PubMed

    Feist, Michele I

    2010-04-01

    The introduction of Talmy's (1985, 2000) typology sparked significant interest in linguistic relativity in the arena of motion language. Through careful analysis of the conflation patterns evident in the language of motion events, Talmy noted that one class of languages, V-languages, tends to encode path along with the fact of motion in motion verbs, while a second class, S-languages, tends to encode manner. In the experimental literature, it was reasoned that speakers may be expected to extend novel verbs in accordance with the lexicalization patterns of their native languages. However, the results regarding this prediction are mixed. In this paper, I examine the interplay between the meaning encoded in the motion verb itself and the meaning encoded in the motion description construction, offering a Gricean explanation for co-occurrence patterns and, by extension, for the mixed results. I then explore the implications of this argument for research on possible language effects on thought in this domain.

  10. Motion Tracking System

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Integrated Sensors, Inc. (ISI), under NASA contract, developed a sensor system for controlling robot vehicles. This technology would enable a robot supply vehicle to automatically dock with Earth-orbiting satellites or the International Space Station. During the docking phase the ISI-developed sensor must sense the satellite's relative motion, then spin so the robot vehicle can adjust its motion to align with the satellite and slowly close until docking is completed. ISI used the sensing/tracking technology as the basis of its OPAD system, which simultaneously tracks an object's movement in six degrees of freedom. Applications include human limb motion analysis, assembly line position analysis and auto crash dummy motion analysis. The NASA technology is also the basis for Motion Analysis Workstation software, a package to simplify the video motion analysis process.

  11. Detecting motion through dynamic refraction.

    PubMed

    Alterman, Marina; Schechner, Yoav Y; Perona, Pietro; Shamir, Joseph

    2013-01-01

    Refraction causes random dynamic distortions in atmospheric turbulence and in views across a water interface. The latter scenario is experienced by submerged animals seeking to detect prey or avoid predators, which may be airborne or on land. Man encounters this when surveying a scene by a submarine or divers while wishing to avoid the use of an attention-drawing periscope. The problem of inverting random refracted dynamic distortions is difficult, particularly when some of the objects in the field of view (FOV) are moving. On the other hand, in many cases, just those moving objects are of interest, as they reveal animal, human, or machine activity. Furthermore, detecting and tracking these objects does not necessitate handling the difficult task of complete recovery of the scene. We show that moving objects can be detected very simply, with low false-positive rates, even when the distortions are very strong and dominate the object motion. Moreover, the moving object can be detected even if it has zero mean motion. While the object and distortion motions are random and unknown, they are mutually independent. This is expressed by a simple motion feature which enables discrimination of moving object points versus the background.

  12. Bacterial motion in narrow capillaries

    PubMed Central

    Ping, Liyan; Wasnik, Vaibhav; Emberly, Eldon

    2014-01-01

    Motile bacteria often have to pass through small tortuous pores in soil or tissue of higher organisms. However, their motion in this prevalent type of niche is not fully understood. Here, we modeled it with narrow glass capillaries and identified a critical radius (Rc) for bacterial motion. Near the surface of capillaries narrower than that, the swimming trajectories are helices. In larger capillaries, they swim in distorted circles. Under non-slip condition, the peritrichous Escherichia coli swam in left-handed helices with an Rc of ∼10 μm near glass surface. However, slipping could occur in the fast monotrichous Pseudomonas fluorescens, when a speed threshold was exceeded, and thus both left-handed and right-handed helices were executed in glass capillaries. In the natural non-cylindrical pores, the near-surface trajectories would be spirals and twisted loops. Engaging in such motions reduces the bacterial migration rate. With a given pore size, the run length and the tumbling angle of the bacterium determine the probability and duration of their near-surface motion. Shear flow and chemotaxis potentially enhance it. Based on this observation, the puzzling previous observations on bacterial migration in porous environments can be interpreted. PMID:25764548

  13. The Personal Motion Platform

    NASA Technical Reports Server (NTRS)

    Park, Brian Vandellyn

    1993-01-01

    The Neutral Body Posture experienced in microgravity creates a biomechanical equilibrium by enabling the internal forces within the body to find their own balance. A patented reclining chair based on this posture provides a minimal stress environment for interfacing with computer systems for extended periods. When the chair is mounted on a 3 or 6 axis motion platform, a generic motion simulator for simulated digital environments is created. The Personal Motion Platform provides motional feedback to the occupant in synchronization with their movements inside the digital world which enhances the simulation experience. Existing HMD based simulation systems can be integrated to the turnkey system. Future developments are discussed.

  14. Measurement of visual motion

    SciTech Connect

    Hildreth, E.C.

    1984-01-01

    This book examines the measurement of visual motion and the use of relative movement to locate the boundaries of physical objects in the environment. It investigates the nature of the computations that are necessary to perform this analysis by any vision system, biological or artificial. Contents: Introduction. Background. Computation of the Velocity Field. An Algorithm to Compute the Velocity Field. The Computation of Motion Discontinuities. Perceptual Studies of Motion Measurement. The Psychophysics of Discontinuity Detection. Neurophysiological Studies of Motion. Summary and Conclusions. References. Author and Subject Indexes.

  15. EDITORIAL: Nanotechnology in motion Nanotechnology in motion

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2012-02-01

    , Toshio Ando from the University of Kanazawa provides an overview of developments that have allowed atomic force microscopy to move from rates of the order of one frame a minute to over a thousand frames per second in constant height mode, as reported by Mervyn Miles and colleagues at Bristol University and University College London [8]. Among the pioneers in the field, Ando's group demonstrated the ability to record the Brownian motion of myosin V molecules on mica with image capture rates of 100 x 100 pixels in 80 ms over a decade ago [9]. The developments unleash the potential of atomic force microscopy to observe the dynamics of biological and materials systems. If seeing is believing, the ability to present real motion pictures of the nanoworld cannot fail to capture the public imagination and stimulate burgeoning new avenues of scientific endeavour. Nearly 350 years on from the publication Micrographia, images in microscopy have moved from the page to the movies. References [1] Binnig G, Quate C F, and Gerber Ch 1986 Phys. Rev. Lett. 56 930-3 [2] Ando T 2012 Nanotechnology 23 062001 [3] J G 1934 Nature 134 635-6 [4] Bharadwaj P, Anger P and Novotny L 2007 Nanotechnology 18 044017 [5] The Nobel Prize in Physics 1986 Nobelprize.org [6] Kim K K, Reina A, Shi Y, Park H, Li L-J, Lee Y H and Kong J 2010 Nanotechnology 21 285205 [7] Phillips D B, Grieve J A, Olof S N, Kocher S J, Bowman R, Padgett M J, Miles M J and Carberry D M 2011 Nanotechnology 22 285503 [8] Picco L M, Bozec L, Ulcinas A, Engledew D J, Antognozzi M, Horton M A and Miles M J 2007 Nanotechnology 18 044030 [9] Ando T, Kodera N, Takai E, Maruyama D, Saito K and Toda A 2001 Proc. Natl. Acad. Sci. 98 12468

  16. General Automatic Components of Motion Sickness

    NASA Technical Reports Server (NTRS)

    Suter, S.; Toscano, W. B.; Kamiya, J.; Naifeh, K.

    1985-01-01

    A body of investigations performed in support of experiments aboard the space shuttle, and designed to counteract the symptoms of Space Adaptation Syndrome, which resemble those of motion sickness on Earth is reviewed. For these supporting studies, the automatic manifestations of earth-based motion sickness was examined. Heart rate, respiration rate, finger pulse volume and basal skin resistance were measured on 127 men and women before, during and after exposure to nauseogenic rotating chair tests. Significant changes in all autonomic responses were observed across the tests. Significant differences in autonomic responses among groups divided according to motion sickness susceptibility were also observed. Results suggest that the examination of autonomic responses as an objective indicator of motion sickness malaise is warranted and may contribute to the overall understanding of the syndrome on Earth and in Space.

  17. Human comfort response to random motions with a dominant vertical motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with vertical acceleration inputs with various power spectra shapes and magnitudes. The data obtained are presented.

  18. Motion compensator for holographic motion picture camera

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1973-01-01

    When reference beam strikes target it undergoes Doppler shift dependent upon target velocity. To compensate, object beam is first reflected from rotating cylinder that revolves in direction opposite to target but at same speed. When beam strikes target it is returned to original frequency and is in phase with reference beam. Alternatively this motion compensator may act on reference beam.

  19. Objects in Motion

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2008-01-01

    Objects in motion attract children. The following activity helps children explore the motion of bodies riding in a vehicle and safely demonstrates the answer to their questions, "Why do I need a seatbelt?" Children will enjoy moving the cup around, even if all they "see" is a cup rather than understanding it represents a car. They will understand…

  20. Teaching Projectile Motion

    ERIC Educational Resources Information Center

    Summers, M. K.

    1977-01-01

    Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)

  1. Making Sense of Motion

    ERIC Educational Resources Information Center

    King, Kenneth

    2005-01-01

    When watching a small child with a toy car, it is seen that interest in motion comes early. Children often suggest speed through sounds such as "RRRrrrRRRooooommMMMmmmm" as the toy car is made to speed up, slow down, or accelerate through a turn. Older children start to consider force and motion studies in more detail, and experiences in school…

  2. Aristotle, Motion, and Rhetoric.

    ERIC Educational Resources Information Center

    Sutton, Jane

    Aristotle rejects a world vision of changing reality as neither useful nor beneficial to human life, and instead he reaffirms both change and eternal reality, fuses motion and rest, and ends up with "well-behaved" changes. This concept of motion is foundational to his world view, and from it emerges his theory of knowledge, philosophy of…

  3. Body Motion and Graphing.

    ERIC Educational Resources Information Center

    Nemirovsky, Ricardo; Tierney, Cornelia; Wright, Tracy

    1998-01-01

    Analyzed two children's use of a computer-based motion detector to make sense of symbolic expressions (Cartesian graphs). Found three themes: (1) tool perspectives, efforts to understand graphical responses to body motion; (2) fusion, emergent ways of talking and behaving that merge symbols and referents; and (3) graphical spaces, when changing…

  4. Naive Conceptions of Motion.

    ERIC Educational Resources Information Center

    McCloskey, Michael

    Two experiments were conducted to characterize the system of beliefs that make up the naive impetus theory of motion and to determine what effects physics instruction has on students' conceptions of motion. Thirteen college students were asked to solve several quantitative problems and were interviewed about their answers in the first experiment.…

  5. Measuring mandibular motions

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Rositano, S.; Taylor, R. C.

    1977-01-01

    Mandibular motion along three axes is measured by three motion transducers on floating yoke that rests against mandible. System includes electronics to provide variety of outputs for data display and processing. Head frame is strapped to test subject's skull to provide fixed point of reference for transducers.

  6. Object motion analysis study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The use of optical data processing (ODP) techniques for motion analysis in two-dimensional imagery was studied. The basic feasibility of this approach was demonstrated, but inconsistent performance of the photoplastic used for recording spatial filters prevented totally automatic operation. Promising solutions to the problems encountered are discussed, and it is concluded that ODP techniques could be quite useful for motion analysis.

  7. Stochastic ground motion simulation

    USGS Publications Warehouse

    Rezaeian, Sanaz; Xiaodan, Sun; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

  8. Present-day plate motions

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Jordan, T. H.

    1977-01-01

    A data set comprising 110 spreading rates, 78 transform fault azimuths and 142 earthquake slip vectors was inverted to yield a new instantaneous plate motion model, designated RM2. The mean averaging interval for the relative motion data was reduced to less than 3 My. A detailed comparison of RM2 with angular velocity vectors which best fit the data along individual plate boundaries indicates that RM2 performs close to optimally in most regions, with several notable exceptions. On the other hand, a previous estimate (RM1) failed to satisfy an extensive set of new data collected in the South Atlantic Ocean. It is shown that RM1 incorrectly predicts the plate kinematics in the South Atlantic because the presently available data are inconsistent with the plate geometry assumed in deriving RM1. It is demonstrated that this inconsistency can be remedied by postulating the existence of internal deformation with the Indian plate, although alternate explanations are possible.

  9. Motion Planning for Rigid Body Robots

    DTIC Science & Technology

    1992-06-01

    Given a non-holonomic disc robot D, its motion constraints in terms of maximum curvature (Kmax) and rate of change of curvature (Kmax), a set W of...further Kmax, constraint to avoid turns that exceed the rate of change of curvature constraint.

  10. Visual-Motion Cueing in Altitude and Yaw Control

    NASA Technical Reports Server (NTRS)

    Johnson, Walter W.; Schroeder, Jeffery; Statler, Irving C. (Technical Monitor)

    1994-01-01

    Research conducted using the Vertical Motion Simulator at the NASA Ames Research Center examined the contributions of platform motion and visual level-of-detail (LOD) cueing to tasks that required altitude and/or yaw control in a simulated AH-64 Apache helicopter. Within the altitude control tasks the LOD manipulation caused optical density to change across altitudes by a small, moderate, or large amount; while platform motion was either present or absent. The results from these tasks showed that both constant optical density and platform motion improved altitude awareness in an altitude repositioning task, while the presence of platform motion also led to improved performance in a vertical rate control task. The yaw control tasks had pilots'sit 4.5 ft in front of the center of rotation, thus subjecting them to both rotational and lateral motions during a yaw. The pilots were required to regulate their yaw, while the platform motion was manipulated in order to present all combinations of the resulting rotational and lateral motion components. Ratings of simulation fidelity and sensed platform motion showed that the pilots were relatively insensitive to the rotational component, but highly aware of the lateral component. Together these findings show that: 1) platform motion cues are important when speed regulation is required during altitude change; 2) platform motion contributes to the perception of movement amplitude; 3) lateral, but not rotational, motion cues are essential to the perception of vehicle yaw; and 4) LOD management yielding constant optical density across altitudes improves altitude awareness.

  11. Motion sickness in migraine sufferers.

    PubMed

    Marcus, Dawn A; Furman, Joseph M; Balaban, Carey D

    2005-12-01

    Motion sickness commonly occurs after exposure to actual motion, such as car or amusement park rides, or virtual motion, such as panoramic movies. Motion sickness symptoms may be disabling, significantly limiting business, travel and leisure activities. Motion sickness occurs in approximately 50% of migraine sufferers. Understanding motion sickness in migraine patients may improve understanding of the physiology of both conditions. Recent literature suggests important relationships between the trigeminal system and vestibular nuclei that may have implications for both motion sickness and migraine. Studies demonstrating an important relationship between serotonin receptors and motion sickness susceptibility in both rodents and humans suggest possible new motion sickness prevention therapies.

  12. Visualizing motion in video

    NASA Astrophysics Data System (ADS)

    Brown, Lisa M.; Crayne, Susan

    2000-05-01

    In this paper, we present a visualization system and method for measuring, inspecting and analyzing motion in video. Starting from a simple motion video, the system creates a still image representation which we call a digital strobe photograph. Similar to visualization techniques used in conventional film photography to capture high-speed motion using strobe lamps or very fast shutters, and to capture time-lapse motion where the shutter is left open, this methodology creates a single image showing the motion of one or a small number of objects over time. Based on digital background subtraction, we assume that the background is stationary or at most slowing changing and that the camera position is fixed. The method is capable of displaying the motion based on a parameter indicating the time step between successive movements. It can also overcome problems of visualizing movement that is obscured by previous movements. The method is used in an educational software tool for children to measure and analyze various motions. Examples are given using simple physical objects such as balls and pendulums, astronomical events such as the path of the stars around the north pole at night, or the different types of locomotion used by snakes.

  13. Motion Recognition and Modifying Motion Generation for Imitation Robot Based on Motion Knowledge Formation

    NASA Astrophysics Data System (ADS)

    Okuzawa, Yuki; Kato, Shohei; Kanoh, Masayoshi; Itoh, Hidenori

    A knowledge-based approach to imitation learning of motion generation for humanoid robots and an imitative motion generation system based on motion knowledge learning and modification are described. The system has three parts: recognizing, learning, and modifying parts. The first part recognizes an instructed motion distinguishing it from the motion knowledge database by the continuous hidden markov model. When the motion is recognized as being unfamiliar, the second part learns it using locally weighted regression and acquires a knowledge of the motion. When a robot recognizes the instructed motion as familiar or judges that its acquired knowledge is applicable to the motion generation, the third part imitates the instructed motion by modifying a learned motion. This paper reports some performance results: the motion imitation of several radio gymnastics motions.

  14. Inflation and cyclotron motion

    NASA Astrophysics Data System (ADS)

    Greensite, Jeff

    2017-01-01

    We consider, in the context of a braneworld cosmology, the motion of the Universe coupled to a four-form gauge field, with constant field strength, defined in higher dimensions. It is found, under rather general initial conditions, that in this situation there is a period of exponential inflation combined with cyclotron motion in the inflaton field space. The main effect of the cyclotron motion is that slow roll conditions on the inflaton potential, which are typically necessary for exponential inflation, can be evaded. There are Landau levels associated with the four-form gauge field, and these correspond to quantum excitations of the inflaton field satisfying unconventional dispersion relations.

  15. Generalized compliant motion primitive

    NASA Astrophysics Data System (ADS)

    Backes, Paul G.

    1994-08-01

    This invention relates to a general primitive for controlling a telerobot with a set of input parameters. The primitive includes a trajectory generator; a teleoperation sensor; a joint limit generator; a force setpoint generator; a dither function generator, which produces telerobot motion inputs in a common coordinate frame for simultaneous combination in sensor summers. Virtual return spring motion input is provided by a restoration spring subsystem. The novel features of this invention include use of a single general motion primitive at a remote site to permit the shared and supervisory control of the robot manipulator to perform tasks via a remotely transferred input parameter set.

  16. Projectile Motion with Mathematica.

    ERIC Educational Resources Information Center

    de Alwis, Tilak

    2000-01-01

    Describes how to use the computer algebra system (CAS) Mathematica to analyze projectile motion with and without air resistance. These experiments result in several conjectures leading to theorems. (Contains 17 references.) (Author/ASK)

  17. Projectile Motion Details.

    ERIC Educational Resources Information Center

    Schnick, Jeffrey W.

    1994-01-01

    Presents an exercise that attempts to correct for the common discrepancies between theoretical and experimental predictions concerning projectile motion using a spring-loaded projectile ball launcher. Includes common correction factors for student use. (MVL)

  18. Toying with Motion.

    ERIC Educational Resources Information Center

    Galus, Pamela J.

    2002-01-01

    Presents a variety of activities that support the development of an understanding of Newton's laws of motion. Activities use toy cars, mobile roads, and a seat-of-nails. Includes a scoring rubric. (DDR)

  19. Vision and Motion Pictures.

    ERIC Educational Resources Information Center

    Grambo, Gregory

    1998-01-01

    Presents activities on persistence of vision that involve students in a hands-on approach to the study of early methods of creating motion pictures. Students construct flip books, a Zoetrope, and an early movie machine. (DDR)

  20. Motion Sickness: First Aid

    MedlinePlus

    ... soon as the motion stops. The more you travel, the more easily you'll adjust to being ... at least 30 to 60 minutes before you travel. Expect drowsiness as a side effect. Consider scopolamine ( ...

  1. A Projectile Motion Bullseye.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1985-01-01

    Explains a projectile motion experiment involving a bow and arrow. Procedures to measure "muzzle" velocity, bow elastic potential energy, range, flight time, wind resistance, and masses are considered. (DH)

  2. Motion Alters Color Appearance

    PubMed Central

    Hong, Sang-Wook; Kang, Min-Suk

    2016-01-01

    Chromatic induction compellingly demonstrates that chromatic context as well as spectral lights reflected from an object determines its color appearance. Here, we show that when one colored object moves around an identical stationary object, the perceived saturation of the stationary object decreases dramatically whereas the saturation of the moving object increases. These color appearance shifts in the opposite directions suggest that normalization induced by the object’s motion may mediate the shift in color appearance. We ruled out other plausible alternatives such as local adaptation, attention, and transient neural responses that could explain the color shift without assuming interaction between color and motion processing. These results demonstrate that the motion of an object affects both its own color appearance and the color appearance of a nearby object, suggesting a tight coupling between color and motion processing. PMID:27824098

  3. Explanations of Superluminal Motion

    NASA Astrophysics Data System (ADS)

    Scheuer, P. A. G.

    Recent developments in models of core-jet sources with apparent superluminal motions are reviewed. Emphasis is given to new versions of the so-called "Christmas tree" model and the relativistic beaming model.

  4. Stroboscopic Goggles for Reduction of Motion Sickness

    NASA Technical Reports Server (NTRS)

    Reschke, M. F.; Somers, Jeffrey T.

    2005-01-01

    A device built around a pair of electronic shutters has been demonstrated to be effective as a prototype of stroboscopic goggles or eyeglasses for preventing or reducing motion sickness. The momentary opening of the shutters helps to suppress a phenomenon that is known in the art as retinal slip and is described more fully below. While a number of different environmental factors can induce motion sickness, a common factor associated with every known motion environment is sensory confusion or sensory mismatch. Motion sickness is a product of misinformation arriving at a central point in the nervous system from the senses from which one determines one s spatial orientation. When information from the eyes, ears, joints, and pressure receptors are all in agreement as to one s orientation, there is no motion sickness. When one or more sensory input(s) to the brain is not expected, or conflicts with what is anticipated, the end product is motion sickness. Normally, an observer s eye moves, compensating for the anticipated effect of motion, in such a manner that the image of an object moving relatively to an observer is held stationary on the retina. In almost every known environment that induces motion sickness, a change in the gain (in the signal-processing sense of gain ) of the vestibular system causes the motion of the eye to fail to hold images stationary on the retina, and the resulting motion of the images is termed retinal slip. The present concept of stroboscopic goggles or eyeglasses (see figure) is based on the proposition that prevention of retinal slip, and hence, the prevention of sensory mismatch, can be expected to reduce the tendency toward motion sickness. A device according to this concept helps to prevent retinal slip by providing snapshots of the visual environment through electronic shutters that are brief enough that each snapshot freezes the image on each retina. The exposure time for each snapshot is less than 5 ms. In the event that a higher

  5. Combined pitching and yawing motion of airplanes

    NASA Technical Reports Server (NTRS)

    Baranoff, A V; Hopf, L

    1931-01-01

    This report treats the following problems: The beginning of the investigated motions is always a setting of the lateral controls, i.e., the rudder or the ailerons. Now, the first interesting question is how the motion would proceed if these settings were kept unchanged for some time; and particularly, what upward motion would set in, how soon, and for how long, since therein lie the dangers of yawing. Two different motions ensue with a high rate of turn and a steep down slope of flight path in both but a marked difference in angle of attack and consequently different character in the resultant aerodynamic forces: one, the "corkscrew" dive at normal angle, and the other, the "spin" at high angle.

  6. Motion recognition from contact force measurement.

    PubMed

    Yabuki, Takumi; Venture, Gentiane

    2013-01-01

    Optical motion capture systems, which are used in broad fields of research, are costly; they need large installation space and calibrations. We find difficulty in applying it in typical homes and care centers. Therefore we propose to use low cost contact force measurement systems to develop rehabilitation and healthcare monitoring tools. Here, we propose a novel algorithm for motion recognition using the feature vector from force data solely obtained during a daily exercise program. We recognized 7 types of movement (Radio Exercises) of two candidates (mean age 22, male). The results show that the recognition rate of each motion has high score (mean: 86.9%). The results also confirm that there is a clustering of each movement in personal exercises data, and a similarity of the clustering even for different candidates thus that motion recognition is possible using contact force data.

  7. Motion of the Scotia sea plates

    USGS Publications Warehouse

    Thomas, C.; Livermore, R.; Pollitz, F.

    2003-01-01

    Earthquake data from the Scotia Arc to early 2002 are reviewed in the light of satellite gravity and other data in order to derive a model for the motion of plates in the Scotia Sea region. Events with magnitude ???5, which occurred on or near the boundaries of the Scotia and Sandwich plates, and for which Centroid Moment Tensor (CMT) solutions are available, are examined. The newer data fill some of the previous sampling gaps along the boundaries of the Scotia and Sandwich plates, and provide tighter constraints on relative motions. Variations in the width of the Brunhes anomaly on evenly spaced marine magnetic profiles over the East Scotia Ridge provide new estimates of Scotia-Sandwich plate spreading rates. Since there are no stable fracture zones in the east Scotia Sea, the mean azimuth of sea floor fabric mapped by sidescan is used to constrain the direction of spreading. 18 new rate estimates and four azimuths from the East Scotia Ridge are combined with 68 selected earthquake slip vectors from the boundaries of the Scotia Sea in a least-squares inversion for the best-fitting set of Euler poles and angular rotation rates describing the 'present-day' motions of the Scotia and Sandwich plates relative to South America and Antarctica. Our preferred model (TLP2003) gives poles that are similar to previous estimates, except for Scotia Plate motion with respect to South America, which is significantly different from earlier estimates; predicted rates of motion also differ slightly. Our results are much more robust than earlier work. We examine the implications of the model for motion and deformation along the various plate boundaries, with particular reference to the North and South Scotia Ridges, where rates are obtained by closure.

  8. PROMOTIONS: PROper MOTION Software

    NASA Astrophysics Data System (ADS)

    Caleb Wherry, John; Sahai, R.

    2009-05-01

    We report on the development of a software tool (PROMOTIONS) to streamline the process of measuring proper motions of material in expanding nebulae. Our tool makes use of IDL's widget programming capabilities to design a unique GUI that is used to compare images of the objects from two epochs. The software allows us to first orient and register the images to a common frame of reference and pixel scale, using field stars in each of the images. We then cross-correlate specific morphological features in order to determine their proper motions, which consist of the proper motion of the nebula as a whole (PM-neb), and expansion motions of the features relative to the center. If the central star is not visible (quite common in bipolar nebulae with dense dusty waists), point-symmetric expansion is assumed and we use the average motion of high-quality symmetric pairs of features on opposite sides of the nebular center to compute PM-neb. This is then subtracted out to determine the individual movements of these and additional features relative to the nebular center. PROMOTIONS should find wide applicability in measuring proper motions in astrophysical objects such as the expanding outflows/jets commonly seen around young and dying stars. We present first results from using PROMOTIONS to successfully measure proper motions in several pre-planetary nebulae (transition objects between the red giant and planetary nebula phases), using images taken 7-10 years apart with the WFPC2 and ACS instruments on board HST. The authors are grateful to NASA's Undergradute Scholars Research Program (USRP) for supporting this research.

  9. Optimal displacement in apparent motion and quadrature models of motion sensing

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1990-01-01

    A grating appears to move if it is displaced by some amount between two brief presentations, or between multiple successive presentations. A number of recent experiments have examined the influence of displacement size upon either the sensitivity to motion, or upon the induced motion aftereffect. Several recent motion models are based upon quadrature filters that respond in opposite quadrants in the spatiotemporal frequency plane. Predictions of the quadrature model are derived for both two-frame and multiframe displays. Quadrature models generally predict an optimal displacement of 1/4 cycle for two-frame displays, but in the multiframe case the prediction depends entirely on the frame rate.

  10. A Stick Motion Compensation System with a Dynamic Model

    NASA Astrophysics Data System (ADS)

    Suzuki, Yasuhiko; Matsubara, Atsushi; Kakino, Yoshiaki; Tsutsui, Kazuhiko

    This paper deals with a stick motion compensation system. Stick motion is trajectory error that happens just after a quadrant change in circular motion on NC machine tools. Recently cylindrical machining with an end mill is often executed instead of boring machining with a bore tool. That is why the accuracy with end mill machining is becoming important. Stick motion extremely damages the accuracy and the quality of the circular parts or free form surfaces on workpieces. In the conventional compensation system, tuning parameters for each combination of radius and feed rate is needed. This research proposes a new stick motion compensation system. The new system has a dynamic model that simulates the friction. The simulated friction consists of two components. One is spring resistance in proportion to a reverse distance from a quadrant change. The other is viscous damping friction in proportion to velocity. The system can compensate stick motions suitably for wide range conditions of radii and feed rate.

  11. Image segmentation via motion vector estimates

    NASA Astrophysics Data System (ADS)

    Abdel-Malek, Aiman A.; Hasekioglu, Orkun; Bloomer, John J.

    1990-07-01

    In the visual world moving edges in the periphery represent vital pieces of information that directs the human foveation mechanism to selectively gather information around these specific locations. This computationally efficient approach of allocating resources at key locations has inspired computer visionists to develop new target detection and hacking algorithms based on motion detection in image sequences. In this study we implemented a recursive algorithm for estimating motion vector fields for each pixel in a sequence of Digital Subtraction Angiography (DSA) images. Velocity information is used to segment the image and perform linear quadratic and acceleration-based frame interpolation to produce an apparent frame rate increase. Our results demonstrate the feasibility of low-rate digital fluoroscopy hence less exposure risks while preserving image quality. Furthermore the technique can be useful in the medical Picture Archival and Communication Systems (PACS) where image data can be compressed by storing and transmiting only the motion fields associated with the moving pixels. 1.

  12. Yugoslav strong motion network

    NASA Astrophysics Data System (ADS)

    Mihailov, Vladimir

    1985-04-01

    Data concerning ground motion and the response of structures during strong earthquakes are necessary for seismic hazard evaluation and the definition of design criteria for structures to be constructed in seismically active zones. The only way to obtain such data is the installation of a strong-motion instrument network. The Yugoslav strong-motion programme was created in 1972 to recover strong-motion response data used by the structural engineering community in developing earthquake resistant design. Instruments, accelerographs SMA-1 and seismoscopes WM-1, were installed in free-field stations and on structures (high-rise buildings, dams, bridges, etc.). A total number of 176 accelerographs and 137 seismoscopes have been installed and are operating in Yugoslavia. The strong-motion programme in Yugoslavia consists of five subactivities: network design, network operation, data processing, network management and research as well as application. All these activities are under the responsibility of IZIIS in cooperation with the Yugoslav Association of Seismology. By 1975 in the realisation of this project participated the CALTECH as cooperative institution in the joint American-Yugoslav cooperative project. The results obtained which are presented in this paper, and their application in the aseismic design justify the necessity for the existence of such a network in Yugoslavia.

  13. The Particle--Motion Problem.

    ERIC Educational Resources Information Center

    Demana, Franklin; Waits, Bert K.

    1993-01-01

    Discusses solutions to real-world linear particle-motion problems using graphing calculators to simulate the motion and traditional analytic methods of calculus. Applications include (1) changing circular or curvilinear motion into linear motion and (2) linear particle accelerators in physics. (MDH)

  14. de Gennes Narrowing Describes the Relative Motion of Protein Domains

    NASA Astrophysics Data System (ADS)

    Hong, Liang; Smolin, Nikolai; Smith, Jeremy C.

    2014-04-01

    The relative motion of structural domains is essential for the biological function of many proteins. Here, by analyzing neutron scattering data and performing molecular dynamics simulations, we find that interdomain motion in several proteins obeys the principle of de Gennes narrowing, in which the wave vector dependence of the interdomain diffusion coefficient is inversely proportional to the interdomain structure factor. Thus, the rate of interdomain motion is inversely proportional to the probability distribution of the spatial configurations of domains.

  15. Motion Information Inferring Scheme for Multi-View Video Coding

    NASA Astrophysics Data System (ADS)

    Koo, Han-Suh; Jeon, Yong-Joon; Jeon, Byeong-Moon

    This letter proposes a motion information inferring scheme for multi-view video coding motivated by the idea that the aspect of motion vector between the corresponding positions in the neighboring view pair is quite similar. The proposed method infers the motion information from the corresponding macroblock in the neighboring view after RD optimization with the existing prediction modes. This letter presents evaluation showing that the method significantly enhances the efficiency especially at high bit rates.

  16. The “Lunching” Effect: Pigeons track motion towards food more than motion away from it

    PubMed Central

    Cabrera, Felipe; Sanabria, Federico; Shelley, David; Killeen, Peter R.

    2009-01-01

    Four experiments measured pigeons' pecking at a small touch-screen image (the CS) that moved toward or away from a source of food (the US). The image's effectiveness as a CS was dependent on its motion, direction, and distance relative to the US. Pecking to the CS increased with proximity to the US when the CS moved toward the US (Experiment 1). This held true even when a departing CS signalled a US of greater magnitude (Experiment 2). Response rates to stationary stimuli were greater the closer they were to the hopper; but rate was less than when the same spot was part of a motion toward food, and greater than when it was part of a motion away (Experiment 3). The rate of responding in all three cases (motion toward, stationary, motion away) decreased exponentially with distance from the hopper. The distance and motion effects observed under these Pavlovian contingencies were different when pecking to the spot was required for reinforcement (Experiment 4). PMID:19591911

  17. Brownian motion of graphene.

    PubMed

    Maragó, Onofrio M; Bonaccorso, Francesco; Saija, Rosalba; Privitera, Giulia; Gucciardi, Pietro G; Iatì, Maria Antonia; Calogero, Giuseppe; Jones, Philip H; Borghese, Ferdinando; Denti, Paolo; Nicolosi, Valeria; Ferrari, Andrea C

    2010-12-28

    Brownian motion is a manifestation of the fluctuation-dissipation theorem of statistical mechanics. It regulates systems in physics, biology, chemistry, and finance. We use graphene as prototype material to unravel the consequences of the fluctuation-dissipation theorem in two dimensions, by studying the Brownian motion of optically trapped graphene flakes. These orient orthogonal to the light polarization, due to the optical constants anisotropy. We explain the flake dynamics in the optical trap and measure force and torque constants from the correlation functions of the tracking signals, as well as comparing experiments with a full electromagnetic theory of optical trapping. The understanding of optical trapping of two-dimensional nanostructures gained through our Brownian motion analysis paves the way to light-controlled manipulation and all-optical sorting of biological membranes and anisotropic macromolecules.

  18. Intrinsic Feature Motion Tracking

    SciTech Connect

    Goddard, Jr., James S.

    2013-03-19

    Subject motion during 3D medical scanning can cause blurring and artifacts in the 3D images resulting in either rescans or poor diagnosis. Anesthesia or physical restraints may be used to eliminate motion but are undesirable and can affect results. This software measures the six degree of freedom 3D motion of the subject during the scan under a rigidity assumption using only the intrinsic features present on the subject area being monitored. This movement over time can then be used to correct the scan data removing the blur and artifacts. The software acquires images from external cameras or images stored on disk for processing. The images are from two or three calibrated cameras in a stereo arrangement. Algorithms extract and track the features over time and calculate position and orientation changes relative to an initial position. Output is the 3D position and orientation change measured at each image.

  19. Motion detector and analyzer

    DOEpatents

    Unruh, W.P.

    1987-03-23

    Method and apparatus are provided for deriving positive and negative Doppler spectrum to enable analysis of objects in motion, and particularly, objects having rotary motion. First and second returned radar signals are mixed with internal signals to obtain an in-phase process signal and a quadrature process signal. A broad-band phase shifter shifts the quadrature signal through 90/degree/ relative to the in-phase signal over a predetermined frequency range. A pair of signals is output from the broad-band phase shifter which are then combined to provide a first side band signal which is functionally related to a negative Doppler shift spectrum. The distinct positive and negative Doppler spectra may then be analyzed for the motion characteristics of the object being examined.

  20. Muscle Motion Solenoid Actuator

    NASA Astrophysics Data System (ADS)

    Obata, Shuji

    It is one of our dreams to mechanically recover the lost body for damaged humans. Realistic humanoid robots composed of such machines require muscle motion actuators controlled by all pulling actions. Particularly, antagonistic pairs of bi-articular muscles are very important in animal's motions. A system of actuators is proposed using the electromagnetic force of the solenoids with the abilities of the stroke length over 10 cm and the strength about 20 N, which are needed to move the real human arm. The devised actuators are based on developments of recent modern electro-magnetic materials, where old time materials can not give such possibility. Composite actuators are controlled by a high ability computer and software making genuine motions.

  1. Motions Recognized through Visual Scene by Pilots and Flight Simulator Tests with Only Lateral-Directional Motions

    NASA Astrophysics Data System (ADS)

    Hayakawa, Masahito; Kobayashi, Osamu

    A flight simulator must exactly simulate the aircraft motion. So, engineers check if the solution of equations of motion, the calculation of flight positions and attitudes, and then, the drawn-up of visual scenery from cockpit windows according to the calculated positions and attitudes are correct. This paper proposes an additional check if the aircraft motion perceived from visual scenery by pilot is same as the calculated motion. This opinion is applied to the simulation case that just lateral-directional flying qualities are evaluated, and it is found that the pitching motion rate (q) and Euler’s pitch attitude rate (Θ) should not be perfectly neglected (i.e. q=Θ=0) but (q and Θ) should be given assuming steady level turn flight should be given. The flight simulator test showed that the pilot felt more real flight motion and controlled some harder than in the condition of q=Θ=0.

  2. Motion in microfluidic ratchets.

    PubMed

    Caballero, D; Katuri, J; Samitier, J; Sánchez, S

    2016-11-15

    The ubiquitous random motion of mesoscopic active particles, such as cells, can be "rectified" or directed by embedding the particles in systems containing local and periodic asymmetric cues. Incorporated on lab-on-a-chip devices, these microratchet-like structures can be used to self-propel fluids, transport particles, and direct cell motion in the absence of external power sources. In this Focus article we discuss recent advances in the use of ratchet-like geometries in microfluidics which could open new avenues in biomedicine for applications in diagnosis, cancer biology, and bioengineering.

  3. Analysis of swimming motions.

    NASA Technical Reports Server (NTRS)

    Gallenstein, J.; Huston, R. L.

    1973-01-01

    This paper presents an analysis of swimming motion with specific attention given to the flutter kick, the breast-stroke kick, and the breast stroke. The analysis is completely theoretical. It employs a mathematical model of the human body consisting of frustrums of elliptical cones. Dynamical equations are written for this model including both viscous and inertia forces. These equations are then applied with approximated swimming strokes and solved numerically using a digital computer. The procedure is to specify the input of the swimming motion. The computer solution then provides the output displacement, velocity, and rotation or body roll of the swimmer.

  4. Induced motion at texture-defined motion boundaries.

    PubMed Central

    Johnston, A; Benton, C P; McOwan, P W

    1999-01-01

    When a static textured background is covered and uncovered by a moving bar of the same mean luminance we can clearly see the motion of the bar. Texture-defined motion provides an example of a naturally occurring second-order motion. Second-order motion sequences defeat standard spatio-temporal energy models of motion perception. It has been proposed that second-order stimuli are analysed by separate systems, operating in parallel with luminance-defined motion processing, which incorporate identifiable pre-processing stages that make second-order patterns visible to standard techniques. However, the proposal of multiple paths to motion analysis remains controversial. Here we describe the behaviour of a model that recovers both luminance-defined and an important class of texture-defined motion. The model also accounts for the induced motion that is seen in some texture-defined motion sequences. We measured the perceived direction and speed of both the contrast envelope and induced motion in the case of a contrast modulation of static noise textures. Significantly, the model predicts the perceived speed of the induced motion seen at second-order texture boundaries. The induced motion investigated here appears distinct from classical induced effects resulting from motion contrast or the movement of a reference frame. PMID:10643088

  5. A test of alternative Caribbean plate relative motion models

    NASA Technical Reports Server (NTRS)

    Stein, Seth; Demets, Charles; Gordon, Richard G.; Brodholt, John; Argus, Don

    1988-01-01

    The new NUVEL-1 data set for global relative plate motions is used here to discriminate between the two prevailing models for Caribbean plate motion. One model, by Jordan (1975), assumes that North America-Caribbean motion is reflected by the spreading rate inferred from magnetic anomalies at the Cayman Spreading Center and the azimuths of nearby transforms. The other model, by Sykes et al. (1982), uses rates and azimuths inferred from the geometry of the Lesser Antilles Wadati-Benioff zone. Overall, it is found that the data fit the Jordan geometry better, that the data used in global plate motion models are more suitable than rates and azimuths inferred from the geometry of the Wadati-Benioff zone for determining relative motions, and that incorporation of all relevant plate boundaries is essential.

  6. Strong Motion Recording in the United States

    NASA Astrophysics Data System (ADS)

    Archuleta, R. J.; Fletcher, J. B.; Shakal, A. F.

    2014-12-01

    The United States strong motion program began in 1932 when the Coast and Geodetic Survey (C&GS) installed eight strong motion accelerographs in California. During the March 1933 Long Beach earthquake, three of these produced the first strong motion records. With this success the C&GS expanded the number of accelerographs to 71 by 1964. With development of less expensive, mass-produced accelerographs the number of strong motion accelerographs expanded to ~575 by 1972. Responsibilities for operating the network and disseminating data were transferred to the National Oceanic and Atmospheric Administration in 1970 and then to the U.S. Geological Survey in 1973. In 1972 the California Legislature established the California Strong Motion Instrumentation Program (CSMIP). CSMIP operates accelerographs at 812 ground stations, with multi-channel accelerographs in 228 buildings, 125 lifelines and 37 geotechnical arrays, in California. The USGS and the ANSS effort operate accelerographs at 1584 ground stations, 96 buildings, 14 bridges, 70 dams, and 15 multi-channel geotechnical arrays. The USC Los Angeles array has 78 ground stations; UCSB operates 5 geotechnical arrays; other government and private institutions also operate accelerographs. Almost all accelerographs are now digital with a sampling rate of 200 Hz. Most of the strong motion data can be downloaded from the Center for Engineering Strong Motion Data (http://strongmotioncenter.org). As accelerographs have become more sophisticated, the concept of what constitutes strong motion has blurred because small earthquakes (M ~3) are well recorded on accelerometers as well as seismometers. However, when accelerations are over ~10%g and velocities over ~1 cm/s, the accelerometers remain on scale, providing the unclipped data necessary to analyze the ground motion and its consequences. Strong motion data are essential to the development of ground motion prediction equations, understanding structural response, performance

  7. A world in motion

    SciTech Connect

    Boynton, J.A.

    1994-12-31

    A World in Motion is a physical science curriculum supplement for grades four, five, and six which responds to the need to promote and teach sound science and mathematics concepts. Using the A World in Motion kits, teachers work in partnership with practicing engineer or scientists volunteers to provide students with fun, exciting, and relevant hands-on science and math experiences. During the A World in Motion experience, students work together in {open_quotes}Engineering Design Teams{close_quotes} exploring physics concepts through a series of activities. Each student is assigned a role as either a facilities engineer, development engineer, test engineer, or project engineer and is given responsibilities paralleling those of engineers in industry. The program culminates in a {open_quotes}Design Review{close_quotes} where students can communicate their results, demonstrate their designs, and receive recognition for their efforts. They are given a chance to take on responsibility and build self-esteem. Since January 1991, over 12,000 volunteers engineers have been involved with the program, with a distribution of 20,000 A World in Motion kit throughout the U.S. and Canada.

  8. Superluminal motion (review)

    NASA Astrophysics Data System (ADS)

    Malykin, G. B.; Romanets, E. A.

    2012-06-01

    Prior to the development of Special Relativity, no restrictions were imposed on the velocity of the motion of particles and material bodies, as well as on energy transfer and signal propagation. At the end of the 19th century and the beginning of the 20th century, it was shown that a charge that moves at a velocity faster than the speed of light in an optical medium, in particular, in vacuum, gives rise to impact radiation, which later was termed the Vavilov-Cherenkov radiation. Shortly after the development of Special Relativity, some researchers considered the possibility of superluminal motion. In 1923, the Soviet physicist L.Ya. Strum suggested the existence of tachyons, which, however, have not been discovered yet. Superluminal motions can occur only for images, e.g., for so-called "light spots," which were considered in 1972 by V.L. Ginzburg and B.M. Bolotovskii. These spots can move with a superluminal phase velocity but are incapable of transferring energy and information. Nevertheless, these light spots may induce quite real generation of microwave radiation in closed waveguides and create the Vavilov-Cherenkov radiation in vacuum. In this work, we consider various paradoxes, illusions, and artifacts associated with superluminal motion.

  9. Linear motion valve

    NASA Technical Reports Server (NTRS)

    Chandler, J. A. (Inventor)

    1985-01-01

    The linear motion valve is described. The valve spool employs magnetically permeable rings, spaced apart axially, which engage a sealing assembly having magnetically permeable pole pieces in magnetic relationship with a magnet. The gap between the ring and the pole pieces is sealed with a ferrofluid. Depletion of the ferrofluid is minimized.

  10. Planets in Motion

    ERIC Educational Resources Information Center

    Riddle, Bob

    2005-01-01

    All the planets in the solar system revolve around the Sun in the same direction, clockwise when viewed from above the North Pole. This is referred to as direct motion. From the perspective on the Earth's surface, the planets travel east across the sky in relation to the background of stars. The Sun also moves eastward daily, but this is an…

  11. Travelers' Health: Motion Sickness

    MedlinePlus

    ... review the actual safety data or call the patient’s obstetric provider for suggestions. Web-based information may be found at the websites www.Motherisk.org and www.Reprotox.org . PREVENTION Nonpharmacologic interventions to prevent or treat motion sickness include the ...

  12. Introducing Simple Harmonic Motion.

    ERIC Educational Resources Information Center

    Roche, John

    2002-01-01

    Explains the origin and significance of harmonic motion which is an important topic that has wide application in the world. Describes the phenomenon by using an auxiliary circle to help illustrate the key relationships between acceleration, displacement, time, velocity, and phase. (Contains 16 references.) (Author/YDS)

  13. Theory of orthodontic motions

    NASA Technical Reports Server (NTRS)

    Pepe, S.; Pepe, W. D.; Strauss, A. M.

    1976-01-01

    A general theory of orthodontic motion is developed that can be applied to determine the forces necessary to induce a given tooth to move to the predetermined desirable position. It is assumed that the natural (nonorthodontic) forces may be represented by a periodic function and the orthodontic forces may be superimposed upon the natural forces. A simple expression is derived for the applied stress.

  14. Solar Motion from Australia

    ERIC Educational Resources Information Center

    Treschman, Keith

    2009-01-01

    At noon throughout the year the Sun has a north-south and east-west motion around the meridian. Earliest/latest sunrises and sunsets do not occur at the solstices and the effect is more pronounced with decreasing latitude. This phenomenon is calculated for 25 Australian cities and the following observations are recorded: (1) The latest sunrise…

  15. Wiimote Experiments: Circular Motion

    ERIC Educational Resources Information Center

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-01-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…

  16. Projectile Motion Revisited.

    ERIC Educational Resources Information Center

    Lucie, Pierre

    1979-01-01

    Analyzes projectile motion using symmetry and simple geometry. Deduces the direction of velocity at any point, range, time of flight, maximum height, safety parabola, and maximum range for a projectile launched upon a plane inclined at any angle with respect to the horizontal. (Author/GA)

  17. Marbles in Motion.

    ERIC Educational Resources Information Center

    Brown, Helen; Meyers, Bernice; Schmidt, William

    1999-01-01

    Marbles were successfully used to help primary students develop concepts of motion. Marble-unit activities began with shaking and rattling inference bags and predicting by listening just how many marbles were in each bag. Students made qualitative and quantitative observations of the marbles, manipulated marbles with a partner, and observed…

  18. Wiimote Experiments: Circular Motion

    NASA Astrophysics Data System (ADS)

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-03-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a bicycle wheel.

  19. Choosing a Motion Detector.

    ERIC Educational Resources Information Center

    Ballard, David M.

    1990-01-01

    Examines the characteristics of three types of motion detectors: Doppler radar, infrared, and ultrasonic wave, and how they are used on school buses to prevent students from being killed by their own school bus. Other safety devices cited are bus crossing arms and a camera monitor system. (MLF)

  20. A Harmonic Motion Experiment

    ERIC Educational Resources Information Center

    Gluck, P.; Krakower, Zeev

    2010-01-01

    We present a unit comprising theory, simulation and experiment for a body oscillating on a vertical spring, in which the simultaneous use of a force probe and an ultrasonic range finder enables one to explore quantitatively and understand many aspects of simple and damped harmonic motions. (Contains 14 figures.)

  1. An "Emergent Model" for Rate of Change

    ERIC Educational Resources Information Center

    Herbert, Sandra; Pierce, Robyn

    2008-01-01

    Does speed provide a "model for" rate of change in other contexts? Does JavaMathWorlds (JMW), animated simulation software, assist in the development of the "model for" rate of change? This project investigates the transference of understandings of rate gained in a motion context to a non-motion context. Students were 27 14-15 year old students at…

  2. Reducing motion artifacts in photoplethysmograms by using relative sensor motion: phantom study

    NASA Astrophysics Data System (ADS)

    Wijshoff, Ralph W. C. G. R.; Mischi, Massimo; Veen, Jeroen; van der Lee, Alexander M.; Aarts, Ronald M.

    2012-11-01

    Currently, photoplethysmograms (PPGs) are mostly used to determine a patient's blood oxygenation and pulse rate. However, PPG morphology conveys more information about the patient's cardiovascular status. Extracting this information requires measuring clean PPG waveforms that are free of artifacts. PPGs are highly susceptible to motion, which can distort the PPG-derived data. Part of the motion artifacts are considered to result from sensor-tissue motion and sensor deformation. It is hypothesized that these motion artifacts correlate with movement of the sensor with respect to the skin. This hypothesis has been proven true in a laboratory setup. In vitro PPGs have been measured in a skin perfusion phantom that is illuminated by a laser diode. Optical motion artifacts are generated in the PPG by translating the laser diode with respect to the PPG photodiode. The optical motion artifacts have been reduced significantly in vitro, by using a normalized least-mean-square algorithm with only a single coefficient that uses the laser's displacement as a reference for the motion artifacts. Laser displacement has been measured accurately via self-mixing interferometry by a compact laser diode with a ball lens integrated into the package, which can be easily integrated into a commercial sensor.

  3. Awake Animal Imaging Motion Tracking Software

    SciTech Connect

    Goddard, James

    2010-03-15

    The Awake Animal Motion Tracking Software code calculates the 3D movement of the head motion of a live, awake animal during a medical imaging scan. In conjunction with markers attached to the head, images acquired from multiple cameras are processed and marker locations precisely determined. Using off-line camera calibration data, the 3D positions of the markers are calculated along with a 6 degree of freedom position and orientation (pose) relative to a fixed initial position. This calculation is performed in real time at frame rates up to 30 frames per second. A time stamp with microsecond accuracy from a time base source is attached to each pose measurement.

  4. The Average of Rates and the Average Rate.

    ERIC Educational Resources Information Center

    Lindstrom, Peter

    1988-01-01

    Defines arithmetic, harmonic, and weighted harmonic means, and discusses their properties. Describes the application of these properties in problems involving fuel economy estimates and average rates of motion. Gives example problems and solutions. (CW)

  5. Coupling between corotation and Lindblad resonances in the presence of secular precession rates

    NASA Astrophysics Data System (ADS)

    El Moutamid, Maryame; Sicardy, Bruno; Renner, Stéfan

    2014-03-01

    We investigate the dynamics of two satellites with masses and orbiting a massive central planet in a common plane, near a first order mean motion resonance ( m integer). We consider only the resonant terms of first order in eccentricity in the disturbing potential of the satellites, plus the secular terms causing the orbital apsidal precessions. We obtain a two-degrees-of-freedom system, associated with the two critical resonant angles and , where and are the mean longitude and longitude of periapsis of , respectively, and where the primed quantities apply to . We consider the special case where (restricted problem). The symmetry between the two angles and is then broken, leading to two different kinds of resonances, classically referred to as corotation eccentric resonance (CER) and Lindblad eccentric Resonance (LER), respectively. We write the four reduced equations of motion near the CER and LER, that form what we call the CoraLin model. This model depends upon only two dimensionless parameters that control the dynamics of the system: the distance between the CER and LER, and a forcing parameter that includes both the mass and the orbital eccentricity of the disturbing satellite. Three regimes are found: for the system is integrable, for of order unity, it exhibits prominent chaotic regions, while for large compared to 2, the behavior of the system is regular and can be qualitatively described using simple adiabatic invariant arguments. We apply this model to three recently discovered small Saturnian satellites dynamically linked to Mimas through first order mean motion resonances: Aegaeon, Methone and Anthe. Poincaré surfaces of section reveal the dynamical structure of each orbit, and their proximity to chaotic regions. This work may be useful to explore various scenarii of resonant capture for those satellites.

  6. An R-D optimized transcoding resilient motion vector selection

    NASA Astrophysics Data System (ADS)

    Aminlou, Alireza; Semsarzadeh, Mehdi; Fatemi, Omid

    2014-12-01

    Selection of motion vector (MV) has a significant impact on the quality of an encoded, and particularly a transcoded video, in terms of rate-distortion (R-D) performance. The conventional motion estimation process, in most existing video encoders, ignores the rate of residuals by utilizing rate and distortion of motion compensation step. This approach implies that the selected MV depends on the quantization parameter. Hence, the same MV that has been selected for high bit rate compression may not be suitable for low bit rate ones when transcoding the video with motion information reuse technique, resulting in R-D performance degradation. In this paper, we propose an R-D optimized motion selection criterion that takes into account the effect of residual rate in MV selection process. Based on the proposed criterion, a new two-piece Lagrange multiplier selection is introduced for motion estimation process. Analytical evaluations indicate that our proposed scheme results in MVs that are less sensitive to changes in bit rate or quantization parameter. As a result, MVs in the encoded bitstream may be used even after the encoded sequence has been transcoded to a lower bit rate one using re-quantization. Simulation results indicate that the proposed technique improves the quality performance of coding and transcoding without any computational overhead.

  7. Phytoplankton's motion in turbulent ocean.

    PubMed

    Fouxon, Itzhak; Leshansky, Alexander

    2015-07-01

    We study the influence of turbulence on upward motion of phytoplankton. Interaction with the flow is described by the Pedley-Kessler model considering spherical microorganisms. We find a range of parameters when the upward drift is only weakly perturbed or when turbulence completely randomizes the drift direction. When the perturbation is small, the drift is either determined by the local vorticity or is Gaussian. We find a range of parameters where the phytoplankton interaction with the flow can be described consistently as diffusion of orientation in effective potential. By solving the corresponding Fokker-Planck equation we find exponential steady-state distribution of phytoplankton's propulsion orientation. We further identify the range of parameters where phytoplankton's drift velocity with respect to the flow is determined uniquely by its position. In this case, one can describe phytoplankton's motion by a smooth flow and phytoplankton concentrates on fractal. We find fractal dimensions and demonstrate that phytoplankton forms vertical stripes in space with a nonisotropic pair-correlation function of concentration increased in the vertical direction. The probability density function of the distance between two particles obeys power law with the negative exponent given by the ratio of integrals of the turbulent energy spectrum. We find the regime of strong clustering where the exponent is of order one so that turbulence increases the rate of collisions by a large factor. The predictions hold for Navier-Stokes turbulence and stand for testing.

  8. Sub-block motion derivation for merge mode in HEVC

    NASA Astrophysics Data System (ADS)

    Chien, Wei-Jung; Chen, Ying; Chen, Jianle; Zhang, Li; Karczewicz, Marta; Li, Xiang

    2016-09-01

    The new state-of-the-art video coding standard, H.265/HEVC, has been finalized in 2013 and it achieves roughly 50% bit rate saving compared to its predecessor, H.264/MPEG-4 AVC. In this paper, two additional merge candidates, advanced temporal motion vector predictor and spatial-temporal motion vector predictor, are developed to improve motion information prediction scheme under the HEVC structure. The proposed method allows each Prediction Unit (PU) to fetch multiple sets of motion information from multiple blocks smaller than the current PU. By splitting a large PU into sub-PUs and filling motion information for all the sub-PUs of the large PU, signaling cost of motion information could be reduced. This paper describes above-mentioned techniques in detail and evaluates their coding performance benefits based on the common test condition during HEVC development. Simulation results show that 2.4% performance improvement over HEVC can be achieved.

  9. Secular motion around synchronously orbiting planetary satellites.

    PubMed

    Lara, Martin; San-Juan, Juan F; Ferrer, Sebastián

    2005-12-01

    We investigate the secular motion of a spacecraft around the natural satellite of a planet. The satellite rotates synchronously with its mean motion around the planet. Our model takes into account the gravitational potential of the satellite up to the second order, and the third-body perturbation in Hill's approximation. Close to the satellite, the ratio of rotation rate of the satellite to mean motion of the orbiter is small. When considering this ratio as a small parameter, the Coriolis effect is a first-order perturbation, while the third-body tidal attraction, the ellipticity effect, and the oblateness perturbation remain at higher orders. Then, we apply perturbation theory and find that a third-order approach is enough to show the influence of the satellite's ellipticity in the pericenter dynamics. Finally, we discuss the averaged system in the three-dimensional parametric space, and provide a global description of the flow.

  10. Linking protein motion to enzyme catalysis.

    PubMed

    Singh, Priyanka; Abeysinghe, Thelma; Kohen, Amnon

    2015-01-13

    Enzyme motions on a broad range of time scales can play an important role in various intra- and intermolecular events, including substrate binding, catalysis of the chemical conversion, and product release. The relationship between protein motions and catalytic activity is of contemporary interest in enzymology. To understand the factors influencing the rates of enzyme-catalyzed reactions, the dynamics of the protein-solvent-ligand complex must be considered. The current review presents two case studies of enzymes-dihydrofolate reductase (DHFR) and thymidylate synthase (TSase)-and discusses the role of protein motions in their catalyzed reactions. Specifically, we will discuss the utility of kinetic isotope effects (KIEs) and their temperature dependence as tools in probing such phenomena.

  11. Exit from Synchrony in Joint Improvised Motion

    PubMed Central

    Dahan, Assi; Noy, Lior; Hart, Yuval; Mayo, Avi; Alon, Uri

    2016-01-01

    Motion synchrony correlates with effective and well-rated human interaction. However, people do not remain locked in synchrony; Instead, they repeatedly enter and exit synchrony. In many important interactions, such as therapy, marriage and parent-infant communication, it is the ability to exit and then re-enter synchrony that is thought to build strong relationship. The phenomenon of entry into zero-phase synchrony is well-studied experimentally and in terms of mathematical modeling. In contrast, exit-from-synchrony is under-studied. Here, we focus on human motion coordination, and examine the exit-from-synchrony phenomenon using experimental data from the mirror game paradigm, in which people perform joint improvised motion, and from human tracking of computer-generated stimuli. We present a mathematical mechanism that captures aspects of exit-from-synchrony in human motion. The mechanism adds a random motion component when the accumulated velocity error between the players is small. We introduce this mechanism to several models for human coordinated motion, including the widely studied HKB model, and the predictor-corrector model of Noy, Dekel and Alon. In all models, the new mechanism produces realistic simulated behavior when compared to experimental data from the mirror game and from tracking of computer generated stimuli, including repeated entry and exit from zero-phase synchrony that generates a complexity of motion similar to that of human players. We hope that these results can inform future research on exit-from-synchrony, to better understand the dynamics of coordinated action of people and to enhance human-computer and human-robot interaction. PMID:27711185

  12. Visible Motion Blur

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B. (Inventor); Ahumada, Albert J. (Inventor)

    2014-01-01

    A method of measuring motion blur is disclosed comprising obtaining a moving edge temporal profile r(sub 1)(k) of an image of a high-contrast moving edge, calculating the masked local contrast m(sub1)(k) for r(sub 1)(k) and the masked local contrast m(sub 2)(k) for an ideal step edge waveform r(sub 2)(k) with the same amplitude as r(sub 1)(k), and calculating the measure or motion blur Psi as a difference function, The masked local contrasts are calculated using a set of convolution kernels scaled to simulate the performance of the human visual system, and Psi is measured in units of just-noticeable differences.

  13. Dynamics of Oceanic Motions

    DTIC Science & Technology

    1988-12-31

    Sciences, Harvard University This project researched the dynamics of oceanic motions: aspects of the theory and mod- eling of fundamental dynamical and...84-C-0461 Published 1. Pinardi, N. (1985) Quasigeostrophic Energetics and Oceanic Mesoscale Dynamics, Harvard University , Cambridge, MA (Ph.D. Thesis...Layer Model to the Harvard Quasigeostrophic Model, Harvard University , Cam- bridge, MA (Ph.D. thesis). 15. Robinson, A.R., M.A. Spell and N. Pinardi

  14. Anomalous Motion Illusion Contributes to Visual Preference

    PubMed Central

    Stevanov, Jasmina; Spehar, Branka; Ashida, Hiroshi; Kitaoka, Akiyoshi

    2012-01-01

    This study investigated the relationship between the magnitude of illusory motion in the variants of the “Rotating Snakes” pattern and the visual preference among such patterns. In Experiment 1 we manipulated the outer contour and the internal geometrical structure of the figure to test for corresponding modulations in the perceived illusion magnitude. The strength of illusory motion was estimated by the method of adjustment where the speed of a standard moving figure was matched to the speed of the perceived illusory motion in test figures. We observed modulation of the perceived strength of illusory motion congruent with our geometrical manipulations. In Experiment 2, we directly compared the magnitude of the perceived illusory motion and the preference for these patterns by a method of paired comparison. Images differing in illusion magnitude showed corresponding differences in the reported preference for these patterns. In addition, further analysis revealed that the geometry and lower level image characteristics also substantially contributed to the observed preference ratings. Together these results support the idea that presence of illusory effect and geometrical characteristics determine affective preference for images, as they may be regarded as more interesting, surprising, or fascinating. PMID:23226138

  15. Molecular Motions During Physical Aging in Polystyrene

    NASA Astrophysics Data System (ADS)

    Thurau, Courtney T.; Ediger, M. D.

    2001-03-01

    A photobleaching method has been used to observe the segmental dynamics of a polystyrene melt during isothermal physical aging. Both rotational and translational diffusion measurements were performed by monitoring the motion of dilute tetracene probes dispersed in the polymer matrix. Following a temperature quench from T_g+2K into the glass, either probe rotational relaxation from an induced anisotropic state, or translational diffusion across a holographic grating, was periodically measured as a function of aging time. Rotation and translation times changed by nearly an order of magnitude during aging. The equilibration times ranged from 10^4-10^7s for the 3 temperatures investigted (T_g-1.4K-T_g-4.6K). Rotational and translational motion age differently. Immediately following a quench, the segmental motions sampled by probe rotation respond more rapidly to the perturbation than the motions sampled by translational motion. At 10^2s, rotational aging has relaxed 60translation shows only a 20T_g-4.5K, it appears that translational diffusion reaches equilibrium before rotation. These differences in aging behavior indicate a change in the distribution of relaxation times throughout the aging process, and may help elucidate the behavior of different observables aging at different rates.

  16. Speed tuning of motion segmentation and discrimination

    NASA Technical Reports Server (NTRS)

    Masson, G. S.; Mestre, D. R.; Stone, L. S.

    1999-01-01

    Motion transparency requires that the visual system distinguish different motion vectors and selectively integrate similar motion vectors over space into the perception of multiple surfaces moving through or over each other. Using large-field (7 degrees x 7 degrees) displays containing two populations of random-dots moving in the same (horizontal) direction but at different speeds, we examined speed-based segmentation by measuring the speed difference above which observers can perceive two moving surfaces. We systematically investigated this 'speed-segmentation' threshold as a function of speed and stimulus duration, and found that it increases sharply for speeds above approximately 8 degrees/s. In addition, speed-segmentation thresholds decrease with stimulus duration out to approximately 200 ms. In contrast, under matched conditions, speed-discrimination thresholds stay low at least out to 16 degrees/s and decrease with increasing stimulus duration at a faster rate than for speed segmentation. Thus, motion segmentation and motion discrimination exhibit different speed selectivity and different temporal integration characteristics. Results are discussed in terms of the speed preferences of different neuronal populations within the primate visual cortex.

  17. Pit disassembly motion control

    SciTech Connect

    Christensen, L.; Pittman, P. C.

    2001-01-01

    A Department of Energy (DOE) Pit Disassembly and Conversion Facility (PDCF) is being designed for the Savannah River Site in South Carolina. The facility will recover plutonium from excess nuclear weapon pits defined in START II and START III treaties. The plutonium will be stored and used to produce mixed oxide reactor fuel at another new DOE facility. Because of radiation dose issues, much of the pit disassembly work and material transfer will be automated. Automated material handling systems will interface with disassembly lathes, conversion reactors that produce oxide for storage, robotic container welding stations, vault retrieval systems, and nondestructive assay (NDA) instrumentation. The goal is to use common motion control hardware for material transfer and possibly common motion controllers for the unique PDCF systems. The latter is complicated by the different directions manufactures are considering for distributed control, such as Firewire, SERCOS, etc., and by the unique control requirements of machines such as lathes compared to controls for an integrated NDA system. The current design approach is to standardize where possible, use network cables to replace wire bundles where possible, but to first select hardware and motion controllers that meet specific machine or process requirements.

  18. Constraints on Planet Nine’s Orbit and Sky Position within a Framework of Mean-motion Resonances

    NASA Astrophysics Data System (ADS)

    Millholland, Sarah; Laughlin, Gregory

    2017-03-01

    A number of authors have proposed that the statistically significant orbital alignment of the most distant Kuiper Belt Objects (KBOs) is evidence of an as-yet undetected planet in the outer solar system, now referred to colloquially as “Planet Nine.” Dynamical simulations by Batygin & Brown have provided constraints on the range of the planet’s possible orbits and sky locations. We extend these investigations by exploring the suggestion of Malhotra et al. that Planet Nine is in small integer ratio mean-motion resonances (MMRs) with several of the most distant KBOs. We show that the observed KBO semimajor axes present a set of commensurabilities with an unseen planet at ∼654 au (P ∼ 16,725 years) that has a greater than 98% chance of stemming from a sequence of MMRs rather than from a random distribution. We describe and implement a Monte-Carlo optimization scheme that drives billion-year dynamical integrations of the outer solar system to pinpoint the orbital properties of perturbers that are capable of maintaining the KBOs’ apsidal alignment. This optimization exercise suggests that the unseen planet is most consistently represented with mass, m ∼ 6–12 M ⊕, semimajor axis, a ∼ 654 au, eccentricity, e ∼ 0.45, inclination, i ∼ 30°, argument of periastron, ω ∼ 150°, longitude of ascending node, Ω ∼ 50°, and mean anomaly, M ∼ 180°. A range of sky locations relative to this fiducial ephemeris are possible. We find that the region 30° ≲ R.A. ≲ 50°, ‑20° ≲ decl. ≲ 20° is promising.

  19. Liquid Motion Experiment Flight Test Results

    NASA Technical Reports Server (NTRS)

    Chato David J.; Dalton, Penni J.; Dodge, Franklin T.; Green, Steve

    1998-01-01

    The Liquid Motion Experiment (LME), designed to study the effects of liquid motion in rotating tanks, was flown on STS 84. LME was essentially a spin table that created a realistic nutation motion of scale-model tanks containing liquid. TWo spherical and two cylindrical transparent tanks were tested simultaneously, and three sets of such tanks were employed to vary liquid viscosity, fill level, and propellant management device (PMD) design. All the tanks were approximately 4.5 inches diameter. The primary test measurements were the radial and tangential torques exerted on the tanks by the liquid. Resonant frequencies and damping of the liquid oscillations were determined by sine sweep tests. For a given tank shape, the resonant frequency depended on fill level. For the cylindrical tanks, the resonances had somewhat different frequencies for the tangential axis (0.55 to 0.75 times spin rate) and the radial axis (0.73 to 0.78 times spin rate), and the tangential axis resonance agreed more closely with available analytical models. For the spherical tanks, the resonant frequencies were between 0.74 to 0.77 times the spin rate and were the same for the tangential and radial axes. The damping coefficients varied from about I% to 3% of critical, depending on tank shape, fill level, and liquid viscosity. 'Me viscous energy dissipation rates of the liquid oscillations were determined from sine dwell tests. The LME energy dissipation rates varied from 0.3 to 0.5 times the estimates obtained from scaling previous ground tests and spacecraft flight data. The PNDs sometimes enhanced the resonances and energy dissipation rates and sometimes decreased them, which points out the need to understand better the effects of PMD on liquid motion as a function of PMD and tank design.

  20. Form-Cue Invariant Motion Processing in Primate Visual Cortex

    NASA Astrophysics Data System (ADS)

    Albright, Thomas D.

    1992-02-01

    The direction and rate at which an object moves are normally not correlated with the manifold physical cues (for example, brightness and texture) that enable it to be seen. As befits its goals, human perception of visual motion largely evades this diversity of cues for image form; direction and rate of motion are perceived (with few exceptions) in a fashion that does not depend on the physical characteristics of the object. The middle temporal visual area of the primate cerebral cortex contains many neurons that respond selectively to motion in a particular direction and is an integral part of the neural substrate for perception of motion. When stimulated with moving patterns characterized by one of three very diverse cues for form, many middle temporal neurons exhibited similar directional tuning. This lack of sensitivity for figural cue characteristics may allow the uniform perception of motion of objects having a broad spectrum of physical cues.

  1. Autoadaptive motion modelling for MR-based respiratory motion estimation.

    PubMed

    Baumgartner, Christian F; Kolbitsch, Christoph; McClelland, Jamie R; Rueckert, Daniel; King, Andrew P

    2017-01-01

    Respiratory motion poses significant challenges in image-guided interventions. In emerging treatments such as MR-guided HIFU or MR-guided radiotherapy, it may cause significant misalignments between interventional road maps obtained pre-procedure and the anatomy during the treatment, and may affect intra-procedural imaging such as MR-thermometry. Patient specific respiratory motion models provide a solution to this problem. They establish a correspondence between the patient motion and simpler surrogate data which can be acquired easily during the treatment. Patient motion can then be estimated during the treatment by acquiring only the simpler surrogate data. In the majority of classical motion modelling approaches once the correspondence between the surrogate data and the patient motion is established it cannot be changed unless the model is recalibrated. However, breathing patterns are known to significantly change in the time frame of MR-guided interventions. Thus, the classical motion modelling approach may yield inaccurate motion estimations when the relation between the motion and the surrogate data changes over the duration of the treatment and frequent recalibration may not be feasible. We propose a novel methodology for motion modelling which has the ability to automatically adapt to new breathing patterns. This is achieved by choosing the surrogate data in such a way that it can be used to estimate the current motion in 3D as well as to update the motion model. In particular, in this work, we use 2D MR slices from different slice positions to build as well as to apply the motion model. We implemented such an autoadaptive motion model by extending our previous work on manifold alignment. We demonstrate a proof-of-principle of the proposed technique on cardiac gated data of the thorax and evaluate its adaptive behaviour on realistic synthetic data containing two breathing types generated from 6 volunteers, and real data from 4 volunteers. On synthetic data

  2. Human motion analysis and modeling

    NASA Astrophysics Data System (ADS)

    Prussing, Keith; Cathcart, J. Michael; Kocher, Brian

    2011-06-01

    Georgia Tech has investigated methods for the detection and tracking of personnel in a variety of acquisition environments. This research effort focused on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. As a fundamental part of this research effort, Georgia Tech collected motion capture data on an individual for a variety of walking speeds, carrying loads, and load distributions. These data formed the basis for deriving fundamental properties of the individual's motion and supported the development of a physiologically-based human motion model. Subsequently this model aided the derivation and analysis of motion-based observables, particularly changes in the motion of various body components resulting from load variations. This paper will describe the data acquisition process, development of the human motion model, and use of the model in the observable analysis. Video sequences illustrating the motion data and modeling results will also be presented.

  3. GROUND MOTION ASSESSMENT BASED ON WEAK MOTION DATA IN TAIWAN Ground Motion Assessment Based on Weak Motion Data in Taiwan

    NASA Astrophysics Data System (ADS)

    Akinci, A.; D'Amico, S.; Malagnini, L.

    2010-12-01

    In this study, we characterize the scaling of the ground motions for frequencies ranging between 0.25 and 5 Hz, obtaining results for seismic attenuation, geometrical spreading, and source parameters in Taiwan. We regressed this large number of weak-motion data in order to characterize the regional propagation and the absolute source scaling. Stochastic simulations are generated for finite-fault ruptures using the obtained parameters to predict the absolute peaks of the ground acceleration and velocity for several magnitude and distance range, as well as beyond the magnitude range of the weak-motion data set on which they are calculated. The predictions are then compared with recorded strong motion data and empirical ground motion prediction equation obtained for the study region. We showed that our regional parameters, obtained from independent weak-motion database, may be applied for evaluation of ground motion parameters for earthquakes of magnitude up to 7.6.

  4. Rotational motion of Vesta

    NASA Astrophysics Data System (ADS)

    Rambaux, N.; Asmar, S. W.; Konopliv, A. S.

    2012-09-01

    Vesta is the second most massive body of the asteroid belt and contains a giant impact and a differentiated interior. Constraints on internal structure can be inferred from various observations such as gravity field measurements [1]. Especially, detailed knowledge of the rotational motion can help constrain the mass distribution inside the body, which in turn can lead to information on its history. Here, we compute the polar motion, precession-nutation, and length-of-day variations of Vesta. The Vesta's Pole position in space has been obtained by Dawn mission [1] and the orbital pole of Vesta at J2000 can be obtained from the Horizons ephemerides [2]. The obliquity, defined as the angle between the normal to the orbital plane and the figure axis, brings information on the moment of inertia if it has reached its equilibrium position [3], the present value from observations is around 27 degrees. That is far from the ˜ 0.03 deg expected for the equilibrium position. In addition, the required timescale to fully damped the obliquity appears to be very long following the same approach developed in [4]. Thus, it appears that the obliquity of Vesta has not yet relaxed in its Cassini state. The figure of Vesta appears to be triaxial and the Sun exerts a non-zero torque. By following the approach developed for the Earth [e.g. 5] and Ceres [4], we compute the nutation of Vesta. The nutational motion of Vesta is dominated by the semi-annual nutation (996 milli-arcseconds or 1.26 m surface displacement) related to the large obliquity of Vesta, and then terms related to harmonics and also to the planet's mean longitude. The detection of such small displacement requires tracking of Vesta's surface with high precision. The precession time of the axis of Vesta is very long, about 179,000 years.

  5. Motion analysis report

    NASA Technical Reports Server (NTRS)

    Badler, N. I.

    1985-01-01

    Human motion analysis is the task of converting actual human movements into computer readable data. Such movement information may be obtained though active or passive sensing methods. Active methods include physical measuring devices such as goniometers on joints of the body, force plates, and manually operated sensors such as a Cybex dynamometer. Passive sensing de-couples the position measuring device from actual human contact. Passive sensors include Selspot scanning systems (since there is no mechanical connection between the subject's attached LEDs and the infrared sensing cameras), sonic (spark-based) three-dimensional digitizers, Polhemus six-dimensional tracking systems, and image processing systems based on multiple views and photogrammetric calculations.

  6. Space motion sickness

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.; Stewart, D. F.; Davis, J. R.

    1986-01-01

    Space motion sickness clinical characteristics, time course, prediction of susceptibility, and effectiveness of countermeasures were evaluated. Although there is wide individual variability, there appear to be typical patterns of symptom development. The duration of symptoms ranges from several hours to four days with the majority of individuals being symptom free by the end of third day. The etiology of this malady remains uncertain but evidence points to reinterpretation of otolith inputs as being a key factor in the response of the neurovestibular system. Prediction of susceptibility and severity remains unsatisfactory. Countermeasures tried include medications, preflight adaptation, and autogenic feedback training. No countermeasure is entirely successful in eliminating or alleviating symptoms.

  7. Motion dynamics of submersibles

    NASA Astrophysics Data System (ADS)

    Kalske, Seppo

    1991-04-01

    A literature survey of motion dynamics of subsea vehicles of a general shape was performed. Hydrodynamic tests were carried out with an existing tethered remotely operated vehicle and with its full scale model. The experiments give data of maneuvering capabilities, and of hydrodynamic characteristics of small subsea vehicles. A simulation method was developed on this basis to compute the vehicle trajectory in the time domain as a function of different control commands. The method can be applied to any subsea vehicle controlled by thruster units.

  8. Human comfort response to random motions with a dominant transverse motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with transverse acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.

  9. Human comfort response to random motions with a dominant longitudinal motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with longitudinal acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.

  10. Human confort response to random motions with a dominant rolling motion

    NASA Technical Reports Server (NTRS)

    Stone, R. W., Jr.

    1975-01-01

    Subjective ride comfort response ratings were measured on a visual motion simulator with rolling velocity inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.

  11. Kink pair production and dislocation motion

    PubMed Central

    Fitzgerald, S. P.

    2016-01-01

    The motion of extended defects called dislocations controls the mechanical properties of crystalline materials such as strength and ductility. Under moderate applied loads, this motion proceeds via the thermal nucleation of kink pairs. The nucleation rate is known to be a highly nonlinear function of the applied load, and its calculation has long been a theoretical challenge. In this article, a stochastic path integral approach is used to derive a simple, general, and exact formula for the rate. The predictions are in excellent agreement with experimental and computational investigations, and unambiguously explain the origin of the observed extreme nonlinearity. The results can also be applied to other systems modelled by an elastic string interacting with a periodic potential, such as Josephson junctions in superconductors. PMID:28004834

  12. Kink pair production and dislocation motion

    NASA Astrophysics Data System (ADS)

    Fitzgerald, S. P.

    2016-12-01

    The motion of extended defects called dislocations controls the mechanical properties of crystalline materials such as strength and ductility. Under moderate applied loads, this motion proceeds via the thermal nucleation of kink pairs. The nucleation rate is known to be a highly nonlinear function of the applied load, and its calculation has long been a theoretical challenge. In this article, a stochastic path integral approach is used to derive a simple, general, and exact formula for the rate. The predictions are in excellent agreement with experimental and computational investigations, and unambiguously explain the origin of the observed extreme nonlinearity. The results can also be applied to other systems modelled by an elastic string interacting with a periodic potential, such as Josephson junctions in superconductors.

  13. Algebraic Nonlinear Collective Motion

    NASA Astrophysics Data System (ADS)

    Troupe, J.; Rosensteel, G.

    1998-11-01

    Finite-dimensional Lie algebras of vector fields determine geometrical collective models in quantum and classical physics. Every set of vector fields on Euclidean space that generates the Lie algebra sl(3, R) and contains the angular momentum algebra so(3) is determined. The subset of divergence-free sl(3, R) vector fields is proven to be indexed by a real numberΛ. TheΛ=0 solution is the linear representation that corresponds to the Riemann ellipsoidal model. The nonlinear group action on Euclidean space transforms a certain family of deformed droplets among themselves. For positiveΛ, the droplets have a neck that becomes more pronounced asΛincreases; for negativeΛ, the droplets contain a spherical bubble of radius |Λ|1/3. The nonlinear vector field algebra is extended to the nonlinear general collective motion algebra gcm(3) which includes the inertia tensor. The quantum algebraic models of nonlinear nuclear collective motion are given by irreducible unitary representations of the nonlinear gcm(3) Lie algebra. These representations model fissioning isotopes (Λ>0) and bubble and two-fluid nuclei (Λ<0).

  14. Waves in Motion

    NASA Astrophysics Data System (ADS)

    McGourty, L.; Rideout, K.

    2005-12-01

    "Waves in Motion" This teaching unit was created by Leslie McGourty and Ken Rideout under the Research Experience for Teachers (RET) program at MIT Haystack Observatory during the summer of 2005. The RET program is funded by a grant from the National Science Foundation. The goals of this teaching unit are to deepen students' understanding about waves, wave motion, and the electromagnetic spectrum as a whole. Specifically students will comprehend the role radio waves play in our daily lives and in the investigation of the universe. The lessons can be used in a high school physics, earth science or astronomy curriculum. The unit consists of a series of interlocking lectures, activities, and investigations that can be used as stand alone units to supplement a teacher's existing curriculum, as an independent investigation for a student, or as a long exploration into radio astronomy with a theme of waves in space: how and where they carry their information. Special emphasis is given to the Relativity theories in honor of the "World Year of Physics" to celebrate Einstein's 1905 contributions. The lessons are currently being implemented at the high school level, the preliminary results of which will be presented. At the end of the academic year, the units will be evaluated and updated, reflecting student input and peer review after which they will be posted on the internet for teachers to use in their classrooms.

  15. Categorizing identity from facial motion.

    PubMed

    Girges, Christine; Spencer, Janine; O'Brien, Justin

    2015-01-01

    Advances in marker-less motion capture technology now allow the accurate replication of facial motion and deformation in computer-generated imagery (CGI). A forced-choice discrimination paradigm using such CGI facial animations showed that human observers can categorize identity solely from facial motion cues. Animations were generated from motion captures acquired during natural speech, thus eliciting both rigid (head rotations and translations) and nonrigid (expressional changes) motion. To limit interferences from individual differences in facial form, all animations shared the same appearance. Observers were required to discriminate between different videos of facial motion and between the facial motions of different people. Performance was compared to the control condition of orientation-inverted facial motion. The results show that observers are able to make accurate discriminations of identity in the absence of all cues except facial motion. A clear inversion effect in both tasks provided consistency with previous studies, supporting the configural view of human face perception. The accuracy of this motion capture technology thus allowed stimuli to be generated that closely resembled real moving faces. Future studies may wish to implement such methodology when studying human face perception.

  16. New motion illusion caused by pictorial motion lines.

    PubMed

    Kawabe, Takahiro; Miura, Kayo

    2008-01-01

    Motion lines (MLs) are a pictorial technique used to represent object movement in a still picture. This study explored how MLs contribute to motion perception. In Experiment 1, we reported the creation of a motion illusion caused by MLs: random displacements of objects with MLs on each frame were perceived as unidirectional global motion along the pictorial motion direction implied by MLs. In Experiment 2, we showed that the illusory global motion in the peripheral visual field captured the perceived motion direction of random displacement of objects without MLs in the central visual field, and confirmed that the results in Experiment 1 did not stem simply from response bias, but resulted from perceptual processing. In Experiment 3, we showed that the spatial arrangement of orientation information rather than ML length is important for the illusory global motion. Our results indicate that the ML effect is based on perceptual processing rather than response bias, and that comparison of neighboring orientation components may underlie the determination of pictorial motion direction with MLs.

  17. What you thought you knew about motion sickness isn't necessarily so

    NASA Technical Reports Server (NTRS)

    Cowings, P. S.; Malmstrom, F. V.

    1984-01-01

    Motion sickness symptoms, stimuli, and drug therapy are discussed. Autogenic feedback training (AFT) methods of preventing motion sickness are explained. Research with AFT indicates that participants who had AFT could withstand longer periods of Coriolis acceleration, participants with high or low susceptibility to motion sickness could control their symptoms with AFT, AFT for Coriolis acceleration is transferable to other motion sickness stimuli, and most people can learn AFT, though with varying rates of learning.

  18. Tvashtar in Motion

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This five-frame sequence of New Horizons images captures the giant plume from Io's Tvashtar volcano. Snapped by the probe's Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Jupiter earlier this year, this first-ever 'movie' of an Io plume clearly shows motion in the cloud of volcanic debris, which extends 330 kilometers (200 miles) above the moon's surface. Only the upper part of the plume is visible from this vantage point -- the plume's source is 130 kilometers (80 miles) below the edge of Io's disk, on the far side of the moon.

    The appearance and motion of the plume is remarkably similar to an ornamental fountain on Earth, replicated on a gigantic scale. The knots and filaments that allow us to track the plume's motion are still mysterious, but this movie is likely to help scientists understand their origin, as well as provide unique information on the plume dynamics.

    Io's hyperactive nature is emphasized by the fact that two other volcanic plumes are also visible off the edge of Io's disk: Masubi at the 7 o'clock position, and a very faint plume, possibly from the volcano Zal, at the 10 o'clock position. Jupiter illuminates the night side of Io, and the most prominent feature visible on the disk is the dark horseshoe shape of the volcano Loki, likely an enormous lava lake. Boosaule Mons, which at 18 kilometers (11 miles) is the highest mountain on Io and one of the highest mountains in the solar system, pokes above the edge of the disk on the right side.

    The five images were obtained over an 8-minute span, with two minutes between frames, from 23:50 to 23:58 Universal Time on March 1, 2007. Io was 3.8 million kilometers (2.4 million miles) from New Horizons; the image is centered at Io coordinates 0 degrees north, 342 degrees west.

    The pictures were part of a sequence designed to look at Jupiter's rings, but planners included Io in the sequence because the moon was passing behind Jupiter's rings at the time.

  19. Strong motion duration and earthquake magnitude relationships

    SciTech Connect

    Salmon, M.W.; Short, S.A.; Kennedy, R.P.

    1992-06-01

    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ``strong motion duration`` has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions.

  20. Effect of vertical motion on current meters

    USGS Publications Warehouse

    Kallio, Nicholas A.

    1966-01-01

    The effect of vertical motion on the performance of current meters at various stream velocities was evaluated to determine whether accurate discharge measurements can be made from a bobbing boat. Three types of current meters--Ott, Price, and vane types--were tested under conditions simulating a bobbing boat. A known frequency and amplitude of vertical motion were imparted to the current meter, and the related effect on the measured stream velocity was determined. One test of the Price meter was made under actual conditions, using a boat and standard measuring gear. The results of the test under actual conditions verified those obtained by simulating the vertical movements of a boat. The tests show that for stream velocities below 2.5 feet per second the accuracy of all three meters is significantly affected when the meters are subjected to certain conditions of vertical motion that can occur during actual field operations. Both the rate of vertical motion and the frequency of vertical oscillation affect the registration of the meter. The results of these tests, presented in the form of graphs and tables, can be used as a guide to determine whether wind and stream flow are within an acceptable range for a reliable discharge measurement from a boat.

  1. Cervical Spinal Motion During Intubation.

    DTIC Science & Technology

    2000-01-01

    Ten fresh human cadavers were intubated while recording cervical motion using a cinefluoroscopic technique. Segmental cervical motion from the...performed using no external stabilization, Gardner-Wells traction and manual in-line cervical immobilization. The data are currently being analyzed. A...paper entitled Segmental cervical spine motion during orotracheal intubation of the intact and injured spine with and without external stabilization was published in the Journal of Neurosurgery.

  2. Collective motion of dimers.

    PubMed

    Penington, Catherine J; Korvasová, Karolína; Hughes, Barry D; Landman, Kerry A

    2012-11-01

    We consider a discrete agent-based model on a one-dimensional lattice and a two-dimensional square lattice, where each agent is a dimer occupying two sites. Agents move by vacating one occupied site in favor of a nearest-neighbor site and obey either a strict simple exclusion rule or a weaker constraint that permits partial overlaps between dimers. Using indicator variables and careful probability arguments, a discrete-time master equation for these processes is derived systematically within a mean-field approximation. In the continuum limit, nonlinear diffusion equations that describe the average agent occupancy of the dimer population are obtained. In addition, we show that multiple species of interacting subpopulations give rise to advection-diffusion equations. Averaged discrete simulation data compares very well with the solution to the continuum partial differential equation models. Since many cell types are elongated rather than circular, this work offers insight into population-level behavior of collective cellular motion.

  3. ANALYSIS OF AIRCRAFT MOTIONS

    NASA Technical Reports Server (NTRS)

    Wingrove, R. C.

    1994-01-01

    This program was developed by Ames Research Center, in cooperation with the National Transportation Safety Board, as a technique for deriving time histories of an aircraft's motion from Air Traffic Control (ATC) radar records. This technique uses the radar range and azimuth data, along with the downlinked altitude data, to derive an expanded set of data which includes airspeed, lift, attitude angles (pitch, roll, and heading), etc. This technique should prove useful as a source of data in the investigation of commercial airline accidents and in the analysis of accidents involving aircraft which do not have onboard data recorders (e.g., military, short-haul, and general aviation). The technique used to determine the aircraft motions involves smoothing of raw radar data. These smoothed results, in combination with other available information (wind profiles and aircraft performance data), are used to derive the expanded set of data. This program uses a cubic least-square fit to smooth the raw data. This moving-arc procedure provides a smoothed time history of the aircraft position, the inertial velocities, and accelerations. Using known winds, these inertial data are transformed to aircraft stability axes to provide true airspeed, thrust-drag, lift, and roll angle. Further derivation, based on aircraft dependent performance data, can determine the aircraft angle of attack, pitch, and heading angle. Results of experimental tests indicate that values derived from ATC radar records using this technique agree favorably with airborne measurements. This program is written in FORTRAN IV to be executed in the batch mode, and has been implemented on a CDC 6000 series computer with a central memory requirement of 64k (octal) of 60 bit words.

  4. Relativistic Brownian motion

    NASA Astrophysics Data System (ADS)

    Dunkel, Jörn; Hänggi, Peter

    2009-02-01

    Over the past one hundred years, Brownian motion theory has contributed substantially to our understanding of various microscopic phenomena. Originally proposed as a phenomenological paradigm for atomistic matter interactions, the theory has since evolved into a broad and vivid research area, with an ever increasing number of applications in biology, chemistry, finance, and physics. The mathematical description of stochastic processes has led to new approaches in other fields, culminating in the path integral formulation of modern quantum theory. Stimulated by experimental progress in high energy physics and astrophysics, the unification of relativistic and stochastic concepts has re-attracted considerable interest during the past decade. Focusing on the framework of special relativity, we review, here, recent progress in the phenomenological description of relativistic diffusion processes. After a brief historical overview, we will summarize basic concepts from the Langevin theory of nonrelativistic Brownian motions and discuss relevant aspects of relativistic equilibrium thermostatistics. The introductory parts are followed by a detailed discussion of relativistic Langevin equations in phase space. We address the choice of time parameters, discretization rules, relativistic fluctuation-dissipation theorems, and Lorentz transformations of stochastic differential equations. The general theory is illustrated through analytical and numerical results for the diffusion of free relativistic Brownian particles. Subsequently, we discuss how Langevin-type equations can be obtained as approximations to microscopic models. The final part of the article is dedicated to relativistic diffusion processes in Minkowski spacetime. Since the velocities of relativistic particles are bounded by the speed of light, nontrivial relativistic Markov processes in spacetime do not exist; i.e., relativistic generalizations of the nonrelativistic diffusion equation and its Gaussian solutions

  5. A true polar wander model for Neoproterozoic plate motions

    SciTech Connect

    Ripperdan, R.L. )

    1992-01-01

    Recent paleogeographic reconstructions for the interval 750--500 Ma (Neoproterozoic to Late Cambrian) require rapid rates of plate motion and/or rotation around an equatorial Euler pole to accommodate reconstructions for the Early Paleozoic. Motions of this magnitude appear to be very uncommon during the Phanerozoic. A model for plate motions based on the hypothesis that discrete intervals of rapid true polar wander (RTPW) occurred during the Neoproterozoic can account for the paleogeographic changes with minimum amounts of plate motion. The model uses the paleogeographic reconstructions of Hoffman (1991). The following constraints were applied during derivation of the model: (1) relative motions between major continental units were restricted to be combinations of great circle or small circle translations with Euler poles of rotation = spin axis; (2) maximum rates of relative translational plate motion were 0.2 m/yr. Based on these constraints, two separate sets of synthetic plate motion trajectories were determined. The sequence of events in both can be summarized as: (1) A rapid true polar wander event of ca 90[degree] rafting a supercontinent to the spin axis; (2) breakup of the polar supercontinent into two fragments, one with the Congo, West Africa, Amazonia, and Baltica cratons, the other with the Laurentia, East Gondwana, and Kalahari cratons; (3) great circle motion of the blocks towards the equator; (4) small circle motion leading to amalgamation of Gondwana and separation of Laurentia and Baltica. In alternative 1, rifting initiates between East Antarctica and Laurentia and one episode of RTPW is required. Alternative 2 requires two episodes of RTPW; and that rifting occurred first along the eastern margin and later along the western margin of Laurentia. Synthetic plate motion trajectories are compared to existing paleomagnetic and geological data, and implications of the model for paleoclimatic changes during the Neoproterozoic are discussed.

  6. Simulation System Fidelity Assessment at the Vertical Motion Simulator

    NASA Technical Reports Server (NTRS)

    Beard, Steven D.; Reardon, Scott E.; Tobias, Eric L.; Aponso, Bimal L.

    2013-01-01

    Fidelity is a word that is often used but rarely understood when talking about groundbased simulation. Assessing the cueing fidelity of a ground based flight simulator requires a comparison to actual flight data either directly or indirectly. Two experiments were conducted at the Vertical Motion Simulator using the GenHel UH-60A Black Hawk helicopter math model that was directly compared to flight data. Prior to the experiment the simulator s motion and visual system frequency responses were measured, the aircraft math model was adjusted to account for the simulator motion system delays, and the motion system gains and washouts were tuned for the individual tasks. The tuned motion system fidelity was then assessed against the modified Sinacori criteria. The first experiments showed similar handling qualities ratings (HQRs) to actual flight for a bob-up and sidestep maneuvers. The second experiment showed equivalent HQRs between flight and simulation for the ADS33 slalom maneuver for the two pilot participants. The ADS33 vertical maneuver HQRs were mixed with one pilot rating the flight and simulation the same while the second pilot rated the simulation worse. In addition to recording HQRs on the second experiment, an experimental Simulation Fidelity Rating (SFR) scale developed by the University of Liverpool was tested for applicability to engineering simulators. A discussion of the SFR scale for use on the Vertical Motion Simulator is included in this paper.

  7. Earthquake ground motion: Chapter 3

    USGS Publications Warehouse

    Luco, Nicolas; Valley, Michael; Crouse, C.B.

    2012-01-01

    Most of the effort in seismic design of buildings and other structures is focused on structural design. This chapter addresses another key aspect of the design process—characterization of earthquake ground motion. Section 3.1 describes the basis of the earthquake ground motion maps in the Provisions and in ASCE 7. Section 3.2 has examples for the determination of ground motion parameters and spectra for use in design. Section 3.3 discusses and provides an example for the selection and scaling of ground motion records for use in response history analysis.

  8. A rigid motion correction method for helical computed tomography (CT)

    NASA Astrophysics Data System (ADS)

    Kim, J.-H.; Nuyts, J.; Kyme, A.; Kuncic, Z.; Fulton, R.

    2015-03-01

    We propose a method to compensate for six degree-of-freedom rigid motion in helical CT of the head. The method is demonstrated in simulations and in helical scans performed on a 16-slice CT scanner. Scans of a Hoffman brain phantom were acquired while an optical motion tracking system recorded the motion of the bed and the phantom. Motion correction was performed by restoring projection consistency using data from the motion tracking system, and reconstructing with an iterative fully 3D algorithm. Motion correction accuracy was evaluated by comparing reconstructed images with a stationary reference scan. We also investigated the effects on accuracy of tracker sampling rate, measurement jitter, interpolation of tracker measurements, and the synchronization of motion data and CT projections. After optimization of these aspects, motion corrected images corresponded remarkably closely to images of the stationary phantom with correlation and similarity coefficients both above 0.9. We performed a simulation study using volunteer head motion and found similarly that our method is capable of compensating effectively for realistic human head movements. To the best of our knowledge, this is the first practical demonstration of generalized rigid motion correction in helical CT. Its clinical value, which we have yet to explore, may be significant. For example it could reduce the necessity for repeat scans and resource-intensive anesthetic and sedation procedures in patient groups prone to motion, such as young children. It is not only applicable to dedicated CT imaging, but also to hybrid PET/CT and SPECT/CT, where it could also ensure an accurate CT image for lesion localization and attenuation correction of the functional image data.

  9. Motion sickness increases functional connectivity between visual motion and nausea-associated brain regions.

    PubMed

    Toschi, Nicola; Kim, Jieun; Sclocco, Roberta; Duggento, Andrea; Barbieri, Riccardo; Kuo, Braden; Napadow, Vitaly

    2017-01-01

    The brain networks supporting nausea not yet understood. We previously found that while visual stimulation activated primary (V1) and extrastriate visual cortices (MT+/V5, coding for visual motion), increasing nausea was associated with increasing sustained activation in several brain areas, with significant co-activation for anterior insula (aIns) and mid-cingulate (MCC) cortices. Here, we hypothesized that motion sickness also alters functional connectivity between visual motion and previously identified nausea-processing brain regions. Subjects prone to motion sickness and controls completed a motion sickness provocation task during fMRI/ECG acquisition. We studied changes in connectivity between visual processing areas activated by the stimulus (MT+/V5, V1), right aIns and MCC when comparing rest (BASELINE) to peak nausea state (NAUSEA). Compared to BASELINE, NAUSEA reduced connectivity between right and left V1 and increased connectivity between right MT+/V5 and aIns and between left MT+/V5 and MCC. Additionally, the change in MT+/V5 to insula connectivity was significantly associated with a change in sympathovagal balance, assessed by heart rate variability analysis. No state-related connectivity changes were noted for the control group. Increased connectivity between a visual motion processing region and nausea/salience brain regions may reflect increased transfer of visual/vestibular mismatch information to brain regions supporting nausea perception and autonomic processing. We conclude that vection-induced nausea increases connectivity between nausea-processing regions and those activated by the nauseogenic stimulus. This enhanced low-frequency coupling may support continual, slowly evolving nausea perception and shifts toward sympathetic dominance. Disengaging this coupling may be a target for biobehavioral interventions aimed at reducing motion sickness severity.

  10. Microsaccades drive illusory motion in the Enigma illusion.

    PubMed

    Troncoso, Xoana G; Macknik, Stephen L; Otero-Millan, Jorge; Martinez-Conde, Susana

    2008-10-14

    Visual images consisting of repetitive patterns can elicit striking illusory motion percepts. For almost 200 years, artists, psychologists, and neuroscientists have debated whether this type of illusion originates in the eye or in the brain. For more than a decade, the controversy has centered on the powerful illusory motion perceived in the painting Enigma, created by op-artist Isia Leviant. However, no previous study has directly correlated the Enigma illusion to any specific physiological mechanism, and so the debate rages on. Here, we show that microsaccades, a type of miniature eye movement produced during visual fixation, can drive illusory motion in Enigma. We asked subjects to indicate when illusory motion sped up or slowed down during the observation of Enigma while we simultaneously recorded their eye movements with high precision. Before "faster" motion periods, the rate of microsaccades increased. Before "slower/no" motion periods, the rate of microsaccades decreased. These results reveal a direct link between microsaccade production and the perception of illusory motion in Enigma and rule out the hypothesis that the origin of the illusion is purely cortical.

  11. Motion Predicts Clinical Callus Formation

    PubMed Central

    Elkins, Jacob; Marsh, J. Lawrence; Lujan, Trevor; Peindl, Richard; Kellam, James; Anderson, Donald D.; Lack, William

    2016-01-01

    Background: Mechanotransduction is theorized to influence fracture-healing, but optimal fracture-site motion is poorly defined. We hypothesized that three-dimensional (3-D) fracture-site motion as estimated by finite element (FE) analysis would influence callus formation for a clinical series of supracondylar femoral fractures treated with locking-plate fixation. Methods: Construct-specific FE modeling simulated 3-D fracture-site motion for sixty-six supracondylar femoral fractures (OTA/AO classification of 33A or 33C) treated at a single institution. Construct stiffness and directional motion through the fracture were investigated to assess the validity of construct stiffness as a surrogate measure of 3-D motion at the fracture site. Callus formation was assessed radiographically for all patients at six, twelve, and twenty-four weeks postoperatively. Univariate and multivariate linear regression analyses examined the effects of longitudinal motion, shear (transverse motion), open fracture, smoking, and diabetes on callus formation. Construct types were compared to determine whether their 3-D motion profile was associated with callus formation. Results: Shear disproportionately increased relative to longitudinal motion with increasing bridge span, which was not predicted by our assessment of construct stiffness alone. Callus formation was not associated with open fracture, smoking, or diabetes at six, twelve, or twenty-four weeks. However, callus formation was associated with 3-D fracture-site motion at twelve and twenty-four weeks. Longitudinal motion promoted callus formation at twelve and twenty-four weeks (p = 0.017 for both). Shear inhibited callus formation at twelve and twenty-four weeks (p = 0.017 and p = 0.022, respectively). Titanium constructs with a short bridge span demonstrated greater longitudinal motion with less shear than did the other constructs, and this was associated with greater callus formation (p < 0.001). Conclusions: In this study of

  12. Pendulum Motion in Main Parachute Clusters

    NASA Technical Reports Server (NTRS)

    Ray, Eric S.; Machin, Ricardo A.

    2015-01-01

    The coupled dynamics of a cluster of parachutes to a payload are notoriously difficult to predict. Often the payload is designed to be insensitive to the range of attitude and rates that might occur, but spacecraft generally do not have the mass and volume budgeted for this robust of a design. The National Aeronautics and Space Administration (NASA) Orion Capsule Parachute Assembly System (CPAS) implements a cluster of three mains for landing. During testing of the Engineering Development Unit (EDU) design, it was discovered that with a cluster of two mains (a fault tolerance required for human rating) the capsule coupled to the parachute cluster could get into a limit cycle pendulum motion which would exceed the spacecraft landing capability. This pendulum phenomenon could not be predicted with the existing models and simulations. A three phased effort has been undertaken to understand the consequence of the pendulum motion observed, and explore potential design changes that would mitigate this phenomenon. This paper will review the early analysis that was performed of the pendulum motion observed during EDU testing, summarize the analysis ongoing to understand the root cause of the pendulum phenomenon, and discuss the modeling and testing that is being pursued to identify design changes that would mitigate the risk.

  13. Plate motions and deformations from geologic and geodetic data

    NASA Technical Reports Server (NTRS)

    Jordan, T. H.

    1986-01-01

    A satellite laser ranging experiment conducted by NASA since 1972 has measured the relative motion between the North America and Pacific plates in California. Based on these measurements, the 896-km distance between San Diego and Quincy, California, is shortening at 62 + or - 9 mm/yr. This geodetic estimate is consistent with the rate of motion between the two plates, calculated from geological data to be 53 + or - 3 mm/yr averaged over the past few million years.

  14. Plate motions and deformations from geologic and geodetic data

    NASA Astrophysics Data System (ADS)

    Jordan, T. H.

    A satellite laser ranging experiment conducted by NASA since 1972 has measured the relative motion between the North America and Pacific plates in California. Based on these measurements, the 896-km distance between San Diego and Quincy, California, is shortening at 62 + or - 9 mm/yr. This geodetic estimate is consistent with the rate of motion between the two plates, calculated from geological data to be 53 + or - 3 mm/yr averaged over the past few million years.

  15. Topographic Structure from Motion

    NASA Astrophysics Data System (ADS)

    Fonstad, M. A.; Dietrich, J. T.; Courville, B. C.; Jensen, J.; Carbonneau, P.

    2011-12-01

    The production of high-resolution topographic datasets is of increasing concern and application throughout the geomorphic sciences, and river science is no exception. Consequently, a wide range of topographic measurement methods have evolved. Despite the range of available methods, the production of high resolution, high quality digital elevation models (DEMs) generally requires a significant investment in personnel time, hardware and/or software. However, image-based methods such as digital photogrammetry have steadily been decreasing in costs. Initially developed for the purpose of rapid, inexpensive and easy three dimensional surveys of buildings or small objects, the "structure from motion" photogrammetric approach (SfM) is a purely image based method which could deliver a step-change if transferred to river remote sensing, and requires very little training and is extremely inexpensive. Using the online SfM program Microsoft Photosynth, we have created high-resolution digital elevation models (DEM) of rivers from ordinary photographs produced from a multi-step workflow that takes advantage of free and open source software. This process reconstructs real world scenes from SfM algorithms based on the derived positions of the photographs in three-dimensional space. One of the products of the SfM process is a three-dimensional point cloud of features present in the input photographs. This point cloud can be georeferenced from a small number of ground control points collected via GPS in the field. The georeferenced point cloud can then be used to create a variety of digital elevation model products. Among several study sites, we examine the applicability of SfM in the Pedernales River in Texas (USA), where several hundred images taken from a hand-held helikite are used to produce DEMs of the fluvial topographic environment. This test shows that SfM and low-altitude platforms can produce point clouds with point densities considerably better than airborne LiDAR, with

  16. The Man Who Mastered Motion.

    ERIC Educational Resources Information Center

    Radetsky, Peter

    1986-01-01

    Explains the principles of the science of motion and examines Thomas Kane's deductive approach to the study of dynamics. Also recounts Kane's advances in explaining classic mechanics and discusses the advantages of his methods in the formulation of equations of motion and in applications to space technology. (ML)

  17. Statistical description of tectonic motions

    NASA Technical Reports Server (NTRS)

    Agnew, Duncan Carr

    1993-01-01

    This report summarizes investigations regarding tectonic motions. The topics discussed include statistics of crustal deformation, Earth rotation studies, using multitaper spectrum analysis techniques applied to both space-geodetic data and conventional astrometric estimates of the Earth's polar motion, and the development, design, and installation of high-stability geodetic monuments for use with the global positioning system.

  18. An open architecture motion controller

    NASA Technical Reports Server (NTRS)

    Rossol, Lothar

    1994-01-01

    Nomad, an open architecture motion controller, is described. It is formed by a combination of TMOS, C-WORKS, and other utilities. Nomad software runs in a UNIX environment and provides for sensor-controlled robotic motions, with user replaceable kinematics. It can also be tailored for highly specialized applications. Open controllers such as Nomad should have a major impact on the robotics industry.

  19. The Equations of Oceanic Motions

    NASA Astrophysics Data System (ADS)

    Müller, Peter

    2006-10-01

    Modeling and prediction of oceanographic phenomena and climate is based on the integration of dynamic equations. The Equations of Oceanic Motions derives and systematically classifies the most common dynamic equations used in physical oceanography, from large scale thermohaline circulations to those governing small scale motions and turbulence. After establishing the basic dynamical equations that describe all oceanic motions, M|ller then derives approximate equations, emphasizing the assumptions made and physical processes eliminated. He distinguishes between geometric, thermodynamic and dynamic approximations and between the acoustic, gravity, vortical and temperature-salinity modes of motion. Basic concepts and formulae of equilibrium thermodynamics, vector and tensor calculus, curvilinear coordinate systems, and the kinematics of fluid motion and wave propagation are covered in appendices. Providing the basic theoretical background for graduate students and researchers of physical oceanography and climate science, this book will serve as both a comprehensive text and an essential reference.

  20. Crowding of biological motion stimuli.

    PubMed

    Ikeda, Hanako; Watanabe, Katsumi; Cavanagh, Patrick

    2013-03-26

    It is difficult to identify a target in the peripheral visual field when it is flanked by distractors. In the present study, we investigated this "crowding" effect for biological motion stimuli. Three walking biological motion stimuli were presented horizontally in the periphery with various distances between them, and observers reported the walking direction of the central figure. When the inter-walker distance was small, discriminating the direction became difficult. Moreover, the reported direction for the central target was not simply noisier, but reflected a degree of pooling of the three directions from the target and two flankers. However, when the two flanking distractors were scrambled walking biological motion stimuli, crowding was not seen. This result suggests that the crowding of biological motion stimuli occurs at a high-level of motion perception.

  1. The Perception of Auditory Motion

    PubMed Central

    Leung, Johahn

    2016-01-01

    The growing availability of efficient and relatively inexpensive virtual auditory display technology has provided new research platforms to explore the perception of auditory motion. At the same time, deployment of these technologies in command and control as well as in entertainment roles is generating an increasing need to better understand the complex processes underlying auditory motion perception. This is a particularly challenging processing feat because it involves the rapid deconvolution of the relative change in the locations of sound sources produced by rotational and translations of the head in space (self-motion) to enable the perception of actual source motion. The fact that we perceive our auditory world to be stable despite almost continual movement of the head demonstrates the efficiency and effectiveness of this process. This review examines the acoustical basis of auditory motion perception and a wide range of psychophysical, electrophysiological, and cortical imaging studies that have probed the limits and possible mechanisms underlying this perception. PMID:27094029

  2. Geophysical Effects of the Earth's Monthly Motion

    NASA Astrophysics Data System (ADS)

    Sidorenkov, N. S.; Zhigailo, T. S.

    The generation of a lunar tidal force is a major geophysical effect of the Earth's monthly motion.It is shown that synoptic processes vary simultaneously with tidal oscillations of the Earth's rotation rate and weather exhibits changes near their extremes, i.e., when the Earth is in certain positions on its monthly orbit.It is found that the quasi-biennial oscillation of the wind direction in the equatorial stratosphere is a combined oscillation caused by three periodic processes experienced by the atmosphere: (a) lunisolar tides, (b) the precession of the orbit of the Earth's monthly rotation around the barycenter of the Earth-Moon system, and (c) the motion of the perigee of this orbit.Interference of the 1.20-year Chandler wobble with sidereal, anomalistic, and synodic lunar oscillations gives rise to beats, i.e., to slow periodic variations in the wobble amplitude with periods of 32 to 51 years.

  3. Motion words selectively modulate direction discrimination sensitivity for threshold motion

    PubMed Central

    Pavan, Andrea; Skujevskis, Māris; Baggio, Giosuè

    2013-01-01

    Can speech selectively modulate the sensitivity of a sensory system so that, in the presence of a suitable linguistic context, the discrimination of certain perceptual features becomes more or less likely? In this study, participants heard upward or downward motion words followed by a single visual field of random dots moving upwards or downwards. The time interval between the onsets of the auditory and the visual stimuli was varied parametrically. Motion direction could be either discriminable (suprathreshold motion) or non-discriminable (threshold motion). Participants had to judge whether the dots were moving upward or downward. Results show a double dissociation between discrimination sensitivity (d′) and reaction times depending on whether vertical motion was above or at threshold. With suprathreshold motion, responses were faster for congruent directions of words and dots, but sensitivity was equal across conditions. With threshold motion, sensitivity was higher for congruent directions of words and dots, but responses were equally fast across conditions. The observed differences in sensitivity and response times were largest when the dots appeared 450 ms after word onset, that is, consistently with electrophysiology, at the time the up/down semantics of the word had become available. These data suggest that word meanings can alter the balance between signal and noise within the visual system and affect the perception of low-level sensory features. PMID:23596407

  4. Estimation, transmission, and distribution of motion information in future image communication networks

    NASA Astrophysics Data System (ADS)

    Chupeau, Bertrand

    1993-10-01

    There is no doubt that in a near future a large number of image processing techniques will be based on motion compensation, making thus very common the cascading of several 'motion compensated' devices in the same image chain. A reference scheme for the optimum use of motion compensation in future image communication networks is presented. Motion estimation is performed once only, at a very early stage of the process chain, then motion information is encoded, transmitted in a separate data channel and distributed to the cascaded motion compensated processes. The distribution scenario must take into consideration the various transformations performed on the image signal since its origination so that the motion information distributed is always consistent with the pictures to process. The problems of the representation of motion relatively to a given source image signal and of its adjustment to new frame rate environments are especially addressed.

  5. The Influence of Motion Cues on Driver-Vehicle Performance in a Simulator

    NASA Technical Reports Server (NTRS)

    Repa, B. S.; Leucht, P. M.; Wierwille, W. W.

    1981-01-01

    Four different motion base configurations were studied on driving simulator. Differently responding vehicles were simulated on each motion configurations and the effects of the vehicle characteristics on driver vehicle system performance, driver control activity, and driver opinion ratings of vehicle performance during driving are compared for different motion configurations. Data show that: (1)) the effects of changes in vehicle characteristics on the different objective and subjective measures of driver vehicle performance are not disguised by the lack of physical motion; (2) fixed base simulator can be used to draw inferences despite the lack of motion; (3) the presence of motion tends to reduce path keeping errors and driver control activity; (4) roll and yaw motions are recommended because of their marked influence on driver vehicle performance (5) the importance of motion increases as the driving maneuvers become more extreme.

  6. Video coding with lifted wavelet transforms and complementary motion-compensated signals

    NASA Astrophysics Data System (ADS)

    Flierl, Markus H.; Vandergheynst, Pierre; Girod, Bernd

    2004-01-01

    This paper investigates video coding with wavelet transforms applied in the temporal direction of a video sequence. The wavelets are implemented with the lifting scheme in order to permit motion compensation between successive pictures. We improve motion compensation in the lifting steps and utilize complementary motion-compensated signals. Similar to superimposed predictive coding with complementary signals, this approach improves compression efficiency. We investigate experimentally and theoretically complementary motion-compensated signals for lifted wavelet transforms. Experimental results with the complementary motion-compensated Haar wavelet and frame-adaptive motion compensation show improvements in coding efficiency of up to 3 dB. The theoretical results demonstrate that the lifted Haar wavelet scheme with complementary motion-compensated signals is able to approach the bound for bit-rate savings of 2 bits per sample and motion-accuracy step when compared to optimum intra-frame coding of the input pictures.

  7. A model for the pilot's use of motion cues in roll-axis tracking tasks

    NASA Technical Reports Server (NTRS)

    Levison, W. H.; Junker, A. M.

    1977-01-01

    Simulated target-following and disturbance-regulation tasks were explored with subjects using visual-only and combined visual and motion cues. The effects of motion cues on task performance and pilot response behavior were appreciably different for the two task configurations and were consistent with data reported in earlier studies for similar task configurations. The optimal-control model for pilot/vehicle systems provided a task-independent framework for accounting for the pilot's use of motion cues. Specifically, the availability of motion cues was modeled by augmenting the set of perceptual variables to include position, rate, acceleration, and accleration-rate of the motion simulator, and results were consistent with the hypothesis of attention-sharing between visual and motion variables. This straightforward informational model allowed accurate model predictions of the effects of motion cues on a variety of response measures for both the target-following and disturbance-regulation tasks.

  8. Assessment of Psychophysiological Responses During Motion Sickness Testing

    NASA Technical Reports Server (NTRS)

    Stoud, Cynthia S.; Toscano, William B.; Cowings, Patricia; Freidman, Gary

    1994-01-01

    The purpose of this investigation is to evaluate a methodology designed to accurately trace the temporal progression of motion sickness and space motion sickness symptoms. With this method, subjects continuously monitor their own motion sickness symptoms during exposure to a provocative stimulus as symptoms occur, in contrast to previous methods during which subjects report symptoms verbally at discrete time intervals. This method not only is comparable to previous methods in the type of symptoms that subjects report, but subjects report symptoms more frequently. Frequent reporting of motion sickness symptoms allows researchers to detail the waxing and waning of motion sickness symptoms for each individual. Previous research has shown that physiological responses to motion sickness stimuli are characterized by unique individual differences in response patterns. By improving our assessment of motion sickness symptoms with continuous monitoring of symptoms, the relationship between specific physiological responses and sickness levels can be more accurately determined for each individual. Results from this study show significant positive relationships between skin conductance levels and symptom levels for ten individuals; a significant positive relationship between temperature and symptom levels for 5 of 10 individuals; and both positive and negative relationships between respiration, heart rate, blood volume pulse and symptom levels. Continuous monitoring of motion sickness symptoms can be used to more accurately assess motion sickness to aid in the evaluation of countermeasures. In addition, recognition of the onset of symptoms that are strongly related to specific physiological responses could be used as cues to initiate procedures (e.g., Autogenic Feedback Training) to prevent the development of severe motion sickness symptoms.

  9. 5 CFR 1201.55 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... for extension of time, a motion for postponement of a hearing, or any other procedural motion must first contact the other party to determine whether there is any objection to the motion, and must state... motion. Judges, in their discretion, may grant or deny motions for extensions of time to file...

  10. Scaling relationship between rotation and translation motions

    NASA Astrophysics Data System (ADS)

    Chiu, Hung-Chie

    2016-04-01

    Rotation motion and its effects are not well known and our knowledge about translation motions is much better than that of the rotation motions. Since rotation motions show to have a close relationship with translation motions, deriving such relationship might improve our understanding on rotation motions. Rotation motion can be obtained by taking a spatial derivative of translation motion. Therefore, rotation motion is always accompanied by translation motions. Although rotation motion cannot be detected by strong motion record, the rotation-induced centrifugal acceleration and gravity effects are recorded in a strong-motion record. In this study we derive empirical relationships for rotation motion and its effects. Results show that rotation motion and its effects are small and can be ignored in weak motion, but they grow up very fast as the increasing of translation motion and become important in near-fault ground motions. We also found that those abnormal strong-motion records observed in near-fault are closely related to rotation motions.

  11. Mab's orbital motion explained

    NASA Astrophysics Data System (ADS)

    Kumar, K.; de Pater, I.; Showalter, M. R.

    2015-07-01

    We explored the hypothesis that Mab's anomalous orbital motion, as deduced from Hubble Space Telescope (HST) data (Showalter, M.R., Lissauer, J.J. [2006]. Science (New York, NY) 311, 973-977), is the result of gravitational interactions with a putative suite of large bodies in the μ-ring. We conducted simulations to compute the gravitational effect of Mab (a recently discovered Uranian moon) on a cloud of test particles. Subsequently, by employing the data extracted from the test particle simulations, we executed random walk simulations to compute the back-reaction of nearby perturbers on Mab. By generating simulated observation metrics, we compared our results to the data retrieved from the HST. Our results indicate that the longitude residual change noted in the HST data (Δλr,Mab ≈ 1 deg) is well matched by our simulations. The eccentricity variations (ΔeMab ≈10-3) are however typically two orders of magnitude too small. We present a variety of reasons that could account for this discrepancy. The nominal scenario that we investigated assumes a perturber ring mass (mring) of 1 mMab (Mab's mass) and a perturber ring number density (ρn,ring) of 10 perturbers per 3 RHill,Mab (Mab's Hill radius). This effectively translates to a few tens of perturbers with radii of approximately 2-3 km, depending on the albedo assumed. The results obtained also include an interesting litmus test: variations of Mab's inclination on the order of the eccentricity changes should be observable. Our work provides clues for further investigation into the tantalizing prospect that the Mab/μ-ring system is undergoing re-accretion after a recent catastrophic disruption.

  12. Motion sickness potentiates core cooling during immersion in humans

    PubMed Central

    Mekjavic, Igor B; Tipton, Michael J; Gennser, Mikael; Eiken, Ola

    2001-01-01

    The present study tested the hypothesis that motion sickness affects thermoregulatory responses to cooling in humans. Ten healthy male volunteers underwent three separate head-out immersions in 28 °C water after different preparatory procedures. In the ‘control’ procedure immersion was preceded by a rest period. In the ‘motion sickness’ procedure immersion was preceded by provocation of motion sickness in a human centrifuge. This comprised rapid and repeated alterations of the gravitational (G-) stress in the head-to-foot direction, plus a standardized regimen of head movements at increased G-stress. In the ‘G-control’ procedure, the subjects were exposed to similar G-stress, but without the motion sickness provocation. During immersion mean skin temperature, rectal temperature, the difference in temperature between the forearm and 3rd digit of the right hand (ΔTforearm-fingertip), oxygen uptake and heart rate were recorded. Subjects provided ratings of temperature perception, thermal comfort and level of motion sickness discomfort at regular intervals. No differences were observed in any of the variables between control and G-control procedures. In the motion sickness procedure, the ΔTforearm-fingertip response was significantly attenuated, indicating a blunted vasoconstrictor response, and rectal temperature decreased at a faster rate. No other differences were observed. Motion sickness attenuates the vasoconstrictor response to skin and core cooling, thereby enhancing heat loss and the magnitude of the fall in deep body temperature. Motion sickness may predispose individuals to hypothermia, and have significant implications for survival time in maritime accidents. PMID:11533150

  13. Human motion analysis and characterization

    NASA Astrophysics Data System (ADS)

    Cathcart, J. Michael; Prussing, Keith; Kocher, Brian

    2011-06-01

    Georgia Tech has investigated methods for the detection and tracking of personnel in a variety of acquisition environments. This research effort focused on a detailed phenomenological analysis of human physiology and signatures with the subsequent identification and characterization of potential observables. Both aspects are needed to support the development of personnel detection and tracking algorithms. As a fundamental part of this research effort, Georgia Tech collected motion capture data on an individual for a variety of walking speeds, carrying loads, and load distributions. These data formed the basis for deriving fundamental properties of the individual's motion and the derivation of motionbased observables, and changes in these fundamental properties arising from load variations. Analyses were conducted to characterize the motion properties of various body components such as leg swing, arm swing, head motion, and full body motion. This paper will describe the data acquisition process, extraction of motion characteristics, and analysis of these data. Video sequences illustrating the motion data and analysis results will also be presented.

  14. Open architecture CMM motion controller

    NASA Astrophysics Data System (ADS)

    Chang, David; Spence, Allan D.; Bigg, Steve; Heslip, Joe; Peterson, John

    2001-12-01

    Although initially the only Coordinate Measuring Machine (CMM) sensor available was a touch trigger probe, technological advances in sensors and computing have greatly increased the variety of available inspection sensors. Non-contact laser digitizers and analog scanning touch probes require very well tuned CMM motion control, as well as an extensible, open architecture interface. This paper describes the implementation of a retrofit CMM motion controller designed for open architecture interface to a variety of sensors. The controller is based on an Intel Pentium microcomputer and a Servo To Go motion interface electronics card. Motor amplifiers, safety, and additional interface electronics are housed in a separate enclosure. Host Signal Processing (HSP) is used for the motion control algorithm. Compared to the usual host plus DSP architecture, single CPU HSP simplifies integration with the various sensors, and implementation of software geometric error compensation. Motion control tuning is accomplished using a remote computer via 100BaseTX Ethernet. A Graphical User Interface (GUI) is used to enter geometric error compensation data, and to optimize the motion control tuning parameters. It is shown that this architecture achieves the required real time motion control response, yet is much easier to extend to additional sensors.

  15. A database of macromolecular motions.

    PubMed Central

    Gerstein, M; Krebs, W

    1998-01-01

    We describe a database of macromolecular motions meant to be of general use to the structural community. The database, which is accessible on the World Wide Web with an entry point at http://bioinfo.mbb.yale.edu/MolMovDB , attempts to systematize all instances of protein and nucleic acid movement for which there is at least some structural information. At present it contains >120 motions, most of which are of proteins. Protein motions are further classified hierarchically into a limited number of categories, first on the basis of size (distinguishing between fragment, domain and subunit motions) and then on the basis of packing. Our packing classification divides motions into various categories (shear, hinge, other) depending on whether or not they involve sliding over a continuously maintained and tightly packed interface. In addition, the database provides some indication about the evidence behind each motion (i.e. the type of experimental information or whether the motion is inferred based on structural similarity) and attempts to describe many aspects of a motion in terms of a standardized nomenclature (e.g. the maximum rotation, the residue selection of a fixed core, etc.). Currently, we use a standard relational design to implement the database. However, the complexity and heterogeneity of the information kept in the database makes it an ideal application for an object-relational approach, and we are moving it in this direction. Specifically, in terms of storing complex information, the database contains plausible representations for motion pathways, derived from restrained 3D interpolation between known endpoint conformations. These pathways can be viewed in a variety of movie formats, and the database is associated with a server that can automatically generate these movies from submitted coordinates. PMID:9722650

  16. TWO SUPER-EARTHS ORBITING THE SOLAR ANALOG HD 41248 ON THE EDGE OF A 7:5 MEAN MOTION RESONANCE

    SciTech Connect

    Jenkins, J. S.; Tuomi, M.; Brasser, R.; Ivanyuk, O.; Murgas, F.

    2013-07-01

    There are a growing number of multi-planet systems known to be orbiting their host stars with orbital periods that place them in mean motion resonances (MMRs). These systems are generally in first-order resonances and dynamical studies have focused their efforts on understanding the origin and evolution of such dynamically resonant commensurabilities. Here we report the discovery of two super-Earths that are close to a second-order dynamical resonance orbiting the metal-poor ([Fe/H] = -0.43 dex) and inactive G2V star HD 41428. We analyzed 62 HARPS archival radial velocities for this star that, until now, exhibited no evidence for planetary companions. Using our new Bayesian Doppler signal detection algorithm, we find two significant signals in the data, with periods of 18.357 days and 25.648 days, indicating they could be part of a 7:5 second-order MMR. Both semi-amplitudes are below 3 m s{sup -1} and the minimum masses of the pair are 12.3 and 8.6 M{sub Circled-Plus }, respectively. Our simulations found that apsidal alignment stabilizes the system, and even though libration of the resonant angles was not seen, the system is affected by the presence of the resonance and could still occupy the 7:5 commensurability, which would be the first planetary configuration in such a dynamical resonance. Given the multitude of low-mass multi-planet systems that will be discovered in the coming years, we expect that more of these second-order resonant configurations will emerge from the data, highlighting the need for a better understanding of the dynamical interactions between forming planetesimals.

  17. Neural mechanisms of motion sickness

    NASA Technical Reports Server (NTRS)

    Crampton, G. H.; Daunton, N. G.

    1983-01-01

    The possibility that there might be a neuro-homoral cerebrospinal fluid link in motion sickness was directly tested by blocking the flow of CSF from the third into the fourth ventricle in cats. Evidence obtained thus far is consistent with the hypothesis. Cats with demonstrably sound plugs did not vomit in response to an accelerative motion sickness stimulus, whereas cats with imperfect 'leaky' plugs vomited with little or no delay in latency. Althoough there are several putative candidates, the identification of a humoral motion sickness substance is a matter of conjecture.

  18. Bubble motion measurements during foam drainage and coarsening.

    PubMed

    Maurdev, G; Saint-Jalmes, A; Langevin, D

    2006-08-15

    We have studied bubble motion within a column of foam allowed to undergo free drainage. We have measured bubble motion upward with time and as a function of their initial positions. Depending on the gas used, which sets the coarsening and drainage rates, different bubble upward motion types have been identified (constant speed, acceleration or deceleration) and explained in relation with liquid downward flows. The proofs of the consistency between bubble upward motion and liquid downward flow are obtained both by comparing the bubble motion curves to the liquid drainage ones, and by comparing the time variations of the liquid fraction extracted from bubble motion to direct liquid fraction measurements by electrical conductimetry. The agreement between bubble position tracking and electrical conductivity shows in particular that it is possible to determine the drainage regime from such simple bubble motion measurements. This work also allowed us to demonstrate a special case of foam coarsening and expansion, occurring when the foam gas is less soluble than the outside one, caused by diffusion of this external gas into the foam. All these results allow us to build a picture of drainage and coarsening seen from the bubble point of view.

  19. Visual motion integration for perception and pursuit

    NASA Technical Reports Server (NTRS)

    Stone, L. S.; Beutter, B. R.; Lorenceau, J.

    2000-01-01

    To examine the relationship between visual motion processing for perception and pursuit, we measured the pursuit eye-movement and perceptual responses to the same complex-motion stimuli. We show that humans can both perceive and pursue the motion of line-figure objects, even when partial occlusion makes the resulting image motion vastly different from the underlying object motion. Our results show that both perception and pursuit can perform largely accurate motion integration, i.e. the selective combination of local motion signals across the visual field to derive global object motion. Furthermore, because we manipulated perceived motion while keeping image motion identical, the observed parallel changes in perception and pursuit show that the motion signals driving steady-state pursuit and perception are linked. These findings disprove current pursuit models whose control strategy is to minimize retinal image motion, and suggest a new framework for the interplay between visual cortex and cerebellum in visuomotor control.

  20. Motional sideband excitation using rotating electric fields

    NASA Astrophysics Data System (ADS)

    Isaac, C. A.

    2013-04-01

    A form of motional sideband excitation is described in which a rotating dipole electric field is applied asymmetrically onto a Penning-type trap in the presence of a mechanism for cooling the axial motion of the trapped particles. In contrast to the traditional motional sideband excitation, which uses an oscillating electric field, the rotating field results in only one active sideband in each sense of rotation and so avoids accidental excitation of the other sideband making it applicable to Penning-type traps with a large degree of anharmonicity. Expressions are derived for the magnetron radius expansion and compression rates attainable, and approximations are made for the case of strong and weak drives. A comparison is made with data, taken using a two-stage positron accumulator presented by Isaac [C. A. Isaac, C. J. Baker, T. Mortensen, D. P. van der Werf, and M. Charlton, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.107.033201 107, 033201 (2011)], showing good agreement between the model and experiment.

  1. Looking at Op Art: Gaze stability and motion illusions

    PubMed Central

    Hermens, Frouke; Zanker, Johannes

    2012-01-01

    Various Op artists have used simple geometrical patterns to create the illusion of motion in their artwork. One explanation for the observed illusion involves retinal shifts caused by small involuntary eye movements that observers make while they try to maintain fixation. Earlier studies have suggested a prominent role of the most conspicuous of these eye movements, small rapid position shifts called microsaccades. Here, we present data that could expand this view with a different interpretation. In three experiments, we recorded participants' eye movements while they tried to maintain visual fixation when being presented with variants of Bridget Riley's Fall, which were manipulated such as to vary the strength of induced motion. In the first two experiments, we investigated the properties of microsaccades for a set of stimuli with known motion strengths. In agreement with earlier observations, microsaccade rates were unaffected by the stimulus pattern and, consequently, the strength of induced motion illusion. In the third experiment, we varied the stimulus pattern across a larger range of parameters and asked participants to rate the perceived motion illusion. The results revealed that motion illusions in patterns resembling Riley's Fall are perceived even in the absence of microsaccades, and that the reported strength of the illusion decreased with the number of microsaccades in the trial. Together, the three experiments suggest that other sources of retinal image instability than microsaccades, such as slow oculomotor drift, should be considered as possible factors contributing to the illusion. PMID:23145284

  2. A primer on motion visual evoked potentials.

    PubMed

    Heinrich, Sven P

    2007-03-01

    Motion visual evoked potentials (motion VEPs) have been used since the late 1960s to investigate the properties of human visual motion processing, and continue to be a popular tool with a possible future in clinical diagnosis. This review first provides a synopsis of the characteristics of motion VEPs and then summarizes important methodological aspects. A subsequent overview illustrates how motion VEPs have been applied to study basic functions of human motion processing and shows perspectives for their use as a diagnostic tool.

  3. Superdiffusive trajectories in Brownian motion.

    PubMed

    Duplat, Jérôme; Kheifets, Simon; Li, Tongcang; Raizen, Mark G; Villermaux, Emmanuel

    2013-02-01

    The Brownian motion of a microscopic particle in a fluid is one of the cornerstones of statistical physics and the paradigm of a random process. One of the most powerful tools to quantify it was provided by Langevin, who explicitly accounted for a short-time correlated "thermal" force. The Langevin picture predicts ballistic motion, ~t(2) at short-time scales, and diffusive motion ~t at long-time scales, where x is the displacement of the particle during time t, and the average is taken over the thermal distribution of initial conditions. The Langevin equation also predicts a superdiffusive regime, where ~t(3), under the condition that the initial velocity is fixed rather than distributed thermally. We analyze the motion of an optically trapped particle in air and indeed find t(3) dispersion. This observation is a direct proof of the existence of the random, rapidly varying force imagined by Langevin.

  4. Projectile Motion in Special Relativity.

    ERIC Educational Resources Information Center

    Naddy, Cory J.; Dudley, Scott C.; Haaland, Ryan K.

    2000-01-01

    Explains the motion that occurs when a particle with an initial velocity to the right is acted upon by a constant downward force. Considers what happens when the speed of the particle approaches the speed of light in particular. (WRM)

  5. Shaft-Motion-Analyzing System

    NASA Technical Reports Server (NTRS)

    Randall, Richard L.; Collins, John J.; Coleman, Paul T.; Roschak, Edmund J.

    1993-01-01

    Optoelectronic system to monitor motions of turbopump shaft developed. Optical sensors detect passage of reflective triangles on shaft. Optical measurements processed in real time into indications of speed of rotation and of axial and lateral displacements of shaft.

  6. Bayesian estimation of turbulent motion.

    PubMed

    Héas, Patrick; Herzet, Cédric; Mémin, Etienne; Heitz, Dominique; Mininni, Pablo D

    2013-06-01

    Based on physical laws describing the multiscale structure of turbulent flows, this paper proposes a regularizer for fluid motion estimation from an image sequence. Regularization is achieved by imposing some scale invariance property between histograms of motion increments computed at different scales. By reformulating this problem from a Bayesian perspective, an algorithm is proposed to jointly estimate motion, regularization hyperparameters, and to select the most likely physical prior among a set of models. Hyperparameter and model inference are conducted by posterior maximization, obtained by marginalizing out non--Gaussian motion variables. The Bayesian estimator is assessed on several image sequences depicting synthetic and real turbulent fluid flows. Results obtained with the proposed approach exceed the state-of-the-art results in fluid flow estimation.

  7. Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?

    SciTech Connect

    Yang, Juan; Cai, Jing; Wang, Hongjun; Chang, Zheng; Czito, Brian G.; Bashir, Mustafa R.; Palta, Manisha; Yin, Fang-Fang

    2014-11-15

    Purpose: To evaluate the relationship between liver tumor motion and diaphragm motion. Methods and Materials: Fourteen patients with hepatocellular carcinoma (10 of 14) or liver metastases (4 of 14) undergoing radiation therapy were included in this study. All patients underwent single-slice cine–magnetic resonance imaging simulations across the center of the tumor in 3 orthogonal planes. Tumor and diaphragm motion trajectories in the superior–inferior (SI), anterior–posterior (AP), and medial–lateral (ML) directions were obtained using an in-house-developed normalized cross-correlation–based tracking technique. Agreement between the tumor and diaphragm motion was assessed by calculating phase difference percentage, intraclass correlation coefficient, and Bland-Altman analysis (Diff). The distance between the tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between the 2 motions. Results: Of all patients, the mean (±standard deviation) phase difference percentage values were 7.1% ± 1.1%, 4.5% ± 0.5%, and 17.5% ± 4.5% in the SI, AP, and ML directions, respectively. The mean intraclass correlation coefficient values were 0.98 ± 0.02, 0.97 ± 0.02, and 0.08 ± 0.06 in the SI, AP, and ML directions, respectively. The mean Diff values were 2.8 ± 1.4 mm, 2.4 ± 1.1 mm, and 2.2 ± 0.5 mm in the SI, AP, and ML directions, respectively. Tumor and diaphragm motions had high concordance when the distance between the tumor and tracked diaphragm area was small. Conclusions: This study showed that liver tumor motion had good correlation with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be used as a reliable surrogate for liver tumor motion.

  8. Hotspot Motion, Before and After the Hawaiian-Emperor Bend

    NASA Astrophysics Data System (ADS)

    Tarduno, J. A.; Bono, R. K.

    2014-12-01

    Hawaiian hotspot motion of >40 mm/yr is best documented by paleomagnetic investigations of basalt cores recovered by ocean drilling of the Emperor seamounts during ODP Leg 197 (Tarduno et al., 2003). These data indicate that the trend of the Emperor Seamounts dominantly records motion of the hotspot in the mantle, further suggesting that the great Hawaiian-Emperor bend (HEB) reflects mainly a change in hotspot motion. Data used for Pacific "absolute plate motion models" for times before the age of the HEB are also internally inconsistent with a fixed hotspot assumption; at present the best way to estimate Pacific absolute plate motion prior to the HEB bend is through use of predictions derived from plate circuits (e.g. Doubrovine and Tarduno, 2008). These analyses predict much less motion for the hotspot responsible for the Louisville Seamount chain, as has been observed by paleomagnetic analyses of cores recovered by IODP Expedition 330 (Koppers et al., 2012). Together, the ocean drilling data sets favor hotspot-specific processes to explain high drift rates, such as the model whereby the Hawaiian mantle plume was captured by a ridge in the Late Cretaceous, and subsequent changes in sub-Pacific mantle flow resulted in the trend of the Emperor Seamounts (Tarduno et al., 2009). However, the question of whether there is a smaller signal of motion between groups of hotspots remains. Plate circuit analyses yield a small discrepancy between predicted and actual hotspot locations for times between ca. 47 Ma and 10 Ma that could be a signal of continued southward migration of the Hawaiian hotspot. Alternatively, this could reflect the motion of the group of Indo-Atlantic hotspots relative to Hawaii. New paleomagnetic data from Midway Atoll (ca. 27 Ma) suggests little difference with the present-day latitude of the plume, indicating that the rate of motion of either the Hawaiian hotspot, or the Indo-Atlantic hotspot group, was about 15 mm/yr between 47 and 27 Ma. This

  9. Engineering uses of physics-based ground motion simulations

    USGS Publications Warehouse

    Baker, Jack W.; Luco, Nicolas; Abrahamson, Norman A.; Graves, Robert W.; Maechling, Phillip J.; Olsen, Kim B.

    2014-01-01

    This paper summarizes validation methodologies focused on enabling ground motion simulations to be used with confidence in engineering applications such as seismic hazard analysis and dynmaic analysis of structural and geotechnical systems. Numberical simullation of ground motion from large erthquakes, utilizing physics-based models of earthquake rupture and wave propagation, is an area of active research in the earth science community. Refinement and validatoin of these models require collaboration between earthquake scientists and engineering users, and testing/rating methodolgies for simulated ground motions to be used with confidence in engineering applications. This paper provides an introduction to this field and an overview of current research activities being coordinated by the Souther California Earthquake Center (SCEC). These activities are related both to advancing the science and computational infrastructure needed to produce ground motion simulations, as well as to engineering validation procedures. Current research areas and anticipated future achievements are also discussed.

  10. Higher Order Fractional Stable Motion: Hyperdiffusion with Heavy Tails

    NASA Astrophysics Data System (ADS)

    Kawai, Reiichiro

    2016-10-01

    We introduce the class of higher order fractional stable motions that can exhibit hyperdiffusive spreading with heavy tails. We define the class as a generalization of higher order fractional Brownian motion as well as a generalization of linear fractional stable motions. Higher order fractional stable motions are self-similar with Hurst index larger than one and non-Gaussian stable marginals with infinite variance and have stationary higher order increments. We investigate their sample path properties and asymptotic dependence structure on the basis of codifference. In particular, by incrementing or decrementing sample paths once under suitable conditions, the diffusion rate can be accelerated or decelerated by one order. With a view towards simulation study, we provide a ready-for-use sample path simulation recipe at discrete times along with error analysis. The proposed simulation scheme requires only elementary numerical operations and is robust to high frequency sampling, irregular spacing and super-sampling.

  11. The Measurement of Visual Motion.

    DTIC Science & Technology

    1982-12-01

    rotates, translates and deforms over time, to yield the dotted curve C2 . The mapping of points from C1 to C2 is much less clear (consider, for example... deforming curve motion; different choices for the velocity field may yield different three-dimensional structures. The computation of a unique velocity...the velocity field, which will allow us to analyze the projected motion of three-dimensional objects 13 L _ allowed to move freely in space, and deform

  12. Tilts in strong ground motion

    USGS Publications Warehouse

    Graizer, V.

    2006-01-01

    Most instruments used in seismological practice to record ground motion are pendulum seismographs, velocigraphs, or accelerographs. In most cases it is assumed that seismic instruments are only sensitive to the translational motion of the instrument's base. In this study the full equation of pendulum motion, including the inputs of rotations and tilts, is considered. It is shown that tilting the accelerograph's base can severely impact its response to the ground motion. The method of tilt evaluation using uncorrected strong-motion accelerograms was first suggested by Graizer (1989), and later tested in several laboratory experiments with different strong-motion instruments. The method is based on the difference in the tilt sensitivity of the horizontal and vertical pendulums. The method was applied to many of the strongest records of the Mw 6.7 Northridge earthquake of 1994. Examples are shown when relatively large tilts of up to a few degrees occurred during strong earthquake ground motion. Residual tilt extracted from the strong-motion record at the Pacoima Dam-Upper Left Abutment reached 3.1?? in N45??E direction, and was a result of local earthquake-induced tilting due to high-amplitude shaking. This value is in agreement with the residual tilt measured by using electronic level a few days after the earthquake. The method was applied to the building records from the Northridge earthquake. According to the estimates, residual tilt reached 2.6?? on the ground floor of the 12-story Hotel in Ventura. Processing of most of the strongest records of the Northridge earthquake shows that tilts, if happened, were within the error of the method, or less than about 0.5??.

  13. Investigation of glassy state molecular motions in thermoset polymers

    NASA Astrophysics Data System (ADS)

    Tu, Jianwei

    This dissertation presents the investigation of the glassy state molecular motions in isomeric thermoset epoxies by means of solid-state deuterium (2H) NMR spectroscopy technique. The network structure of crosslinked epoxies was altered through monomer isomerism; specifically, diglycidyl ether of bisphenol A (DGEBA) was cured with isomeric amine curatives, i.e., the meta-substituted diaminodiphenylsulfone (33DDS) and para-substituted diaminodiphenylsulfone (44DDS). The use of structural isomerism provided a path way for altering macroscopic material properties while maintaining identical chemical composition within the crosslinked networks. The effects of structural isomerism on the glassy state molecular motions were studied using solid-state 2H NMR spectroscopy, which offers unrivaled power to monitor site-specific molecular motions. Three distinctive molecular groups on each isomeric network, i.e., the phenylene rings in the bisphenol A structure (BPA), the phenylene rings in the diaminodiphenylsulfone structure (DDS), and the hydroxypropoyl ether group (HPE) have been selectively deuterated for a comprehensive study of the structure-dynamics- property relationships in thermoset epoxies. Quadrupolar echo experiments and line shape simulations were employed as the main research approach to gain both qualitative and quantitative motional information of the epoxy networks in the glassy state. Quantitative information on the geometry and rate of the molecular motions allows the elucidation of the relationship between molecular motions and macro physical properties and the role of these motions in the mechanical relaxation. Specifically, it is revealed that both the BPA and HPE moieties in the isomeric networks have almost identical behaviors in the deep glassy state, which indicates that the molecular motions in the glassy state are localized, and the correlation length of the motions does not exceed the length of the DGEBA repeat unit. BPA ring motions contribute

  14. Vertical land motion of Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Melbourne, T. I.; Montillet, J. P.; Szeliga, W. M.

    2015-12-01

    We use GPS measurements from 400 stations located throughout the Pacific Northwest to estimate steady-state vertical land motion for the purpose of constraining relative sea level rise projections. Vertical motions are typically only a few percent of horizontal rates and the same order of magnitude as current sea level rise rates, so may either ameliorate or exacerbate future climate impacts. We use data from receivers operating from 1994 through 2015, each with at least three years of continuous daily measurements. Furthermore, daily position time series resulting from the processing of two GPS centers, namely the EarthScope Plate Boundary Observatory (PBO) and the Pacific Northwest Geodetic Array (PANGA), are considered throughout this study. The goal is two fold: the dissemination into the scientific community of the difference in processing between these two centers, and the level of agreement between the estimated crustal for future sea-level studies in the Pacific Northwest. We model both target and reference frame receiver trajectories as a superposition of discrete processes comprising steady-state tectonic motion, annual and bi-annual sinusoids exhibiting stationary phase and amplitude that reflect both local hydrology as well as artifacts introduced through satellite clock and orbit corrections, and discrete offsets due to known earthquakes (with Mw > 6) and hardware changes. Qualitatively, Vancouver Island shows long-term uplift of ~2 mm/year, consistent with both interseismic strain accumulation from the Juan de Fuca subduction along the coast and post-glacial rebound inland, and consistent with earlier reports based on few stations and shorter time series. Further south, coastal uplift rates transition to near-zero south of Pacific Beach, and remain low southward to Cape Blanco. Vertical motion is more heterogeneous throughout Puget Sound, but most regions show subsidence of ~0.5 - 1 mm/yr. The predominant subsidence throughout Puget Sound, where the

  15. Optimised motion tracking for positron emission tomography studies of brain function in awake rats.

    PubMed

    Kyme, Andre Z; Zhou, Victor W; Meikle, Steven R; Baldock, Clive; Fulton, Roger R

    2011-01-01

    Positron emission tomography (PET) is a non-invasive molecular imaging technique using positron-emitting radioisotopes to study functional processes within the body. High resolution PET scanners designed for imaging rodents and non-human primates are now commonplace in preclinical research. Brain imaging in this context, with motion compensation, can potentially enhance the usefulness of PET by avoiding confounds due to anaesthetic drugs and enabling freely moving animals to be imaged during normal and evoked behaviours. Due to the frequent and rapid motion exhibited by alert, awake animals, optimal motion correction requires frequently sampled pose information and precise synchronisation of these data with events in the PET coincidence data stream. Motion measurements should also be as accurate as possible to avoid degrading the excellent spatial resolution provided by state-of-the-art scanners. Here we describe and validate methods for optimised motion tracking suited to the correction of motion in awake rats. A hardware based synchronisation approach is used to achieve temporal alignment of tracker and scanner data to within 10 ms. We explored the impact of motion tracker synchronisation error, pose sampling rate, rate of motion, and marker size on motion correction accuracy. With accurate synchronisation (<100 ms error), a sampling rate of >20 Hz, and a small head marker suitable for awake animal studies, excellent motion correction results were obtained in phantom studies with a variety of continuous motion patterns, including realistic rat motion (<5% bias in mean concentration). Feasibility of the approach was also demonstrated in an awake rat study. We conclude that motion tracking parameters needed for effective motion correction in preclinical brain imaging of awake rats are achievable in the laboratory setting. This could broaden the scope of animal experiments currently possible with PET.

  16. Slow motion increases perceived intent

    PubMed Central

    Caruso, Eugene M.; Burns, Zachary C.; Converse, Benjamin A.

    2016-01-01

    To determine the appropriate punishment for a harmful action, people must often make inferences about the transgressor’s intent. In courtrooms and popular media, such inferences increasingly rely on video evidence, which is often played in “slow motion.” Four experiments (n = 1,610) involving real surveillance footage from a murder or broadcast replays of violent contact in professional football demonstrate that viewing an action in slow motion, compared with regular speed, can cause viewers to perceive an action as more intentional. This slow motion intentionality bias occurred, in part, because slow motion video caused participants to feel like the actor had more time to act, even when they knew how much clock time had actually elapsed. Four additional experiments (n = 2,737) reveal that allowing viewers to see both regular speed and slow motion replay mitigates the bias, but does not eliminate it. We conclude that an empirical understanding of the effect of slow motion on mental state attribution should inform the life-or-death decisions that are currently based on tacit assumptions about the objectivity of human perception. PMID:27482091

  17. Effects of cardiac motion on right coronary artery hemodynamics.

    PubMed

    Zeng, Dehong; Ding, Zhaohua; Friedman, Morton H; Ethier, C Ross

    2003-04-01

    The purpose of this work was to investigate the effects of physiologically realistic cardiac-induced motion on hemodynamics in human right coronary arteries. The blood flow patterns were numerically simulated in a modeled right coronary artery (RCA) having a uniform circular cross section of 2.48 mm diam. Arterial motion was specified based on biplane cineangiograms, and incorporated physiologically realistic bending and torsion. Simulations were carried out with steady and pulsatile inflow conditions (mean ReD=233, alpha=1.82) in both fixed and moving RCA models, to evaluate the relative importance of RCA motion, flow pulsation, and the interaction between motion and flow pulsation. RCA motion with a steady inlet flow rate caused variations in wall shear stress (WSS) magnitude up to 150% of the inlet Poiseuille value. There was significant spatial variability in the magnitude of this motion-induced WSS variation. However, the time-averaged WSS distribution was similar to that predicted in a static model representing the time-averaged geometry. Furthermore, the effects of flow pulsatility dominated RCA motion-induced effects; specifically, there were only modest differences in the WSS history between simulations conducted in fixed and moving RCA models with pulsatile inflow. RCA motion has little effect on time-averaged WSS patterns. It has a larger effect on the temporal variation of WSS, but even this effect is overshadowed by the variations in WSS due to flow pulsation. The hemodynamic effects of RCA motion can, therefore, be ignored as a first approximation in modeling studies.

  18. Martian Landscapes in Motion

    NASA Astrophysics Data System (ADS)

    Mattson, Sarah; McEwen, Alfred; Kirk, Randolph; Howington-Kraus, Elpitha; Chojnacki, Matthew; Runyon, Kirby; Cremonese, Gabriele; Re, Cristina

    2014-05-01

    RISE orthorectified image sequences makes it possible to conduct accurate change detection studies of active processes on Mars. Some examples of studies of active landscapes on Mars using HiRISE DTMs and orthoimage sequences include: dune and ripple motion (Bridges et al., 2012, Nature), recurring slope lineae (RSL) (McEwen et al., 2011, Science; McEwen et al., 2013, Nature Geoscience), gully activity (Dundas et al., 2012, Icarus), and polar processes (Hansen et al., 2011, Science; Portyankina et al. 2013, Icarus,). These studies encompass images from multiple Mars years and seasons. Sequences of orthoimages make it possible to generate animated gifs or movies to visualize temporal changes (http://www.uahirise.org/sim/). They can also be brought into geospatial software to quantitatively map and record changes. The ability to monitor the surface of Mars at high spatial resolution with frequent repeat images has opened up our insight into seasonal and interannual changes, further increasing our understanding of Mars as an active planet.

  19. Example-Based Automatic Music-Driven Conventional Dance Motion Synthesis

    SciTech Connect

    Xu, Songhua; Fan, Rukun; Geng, Weidong

    2012-01-01

    We introduce a novel method for synthesizing dance motions that follow the emotions and contents of a piece of music. Our method employs a learning-based approach to model the music to motion mapping relationship embodied in example dance motions along with those motions' accompanying background music. A key step in our method is to train a music to motion matching quality rating function through learning the music to motion mapping relationship exhibited in synchronized music and dance motion data, which were captured from professional human dance performance. To generate an optimal sequence of dance motion segments to match with a piece of music, we introduce a constraint-based dynamic programming procedure. This procedure considers both music to motion matching quality and visual smoothness of a resultant dance motion sequence. We also introduce a two-way evaluation strategy, coupled with a GPU-based implementation, through which we can execute the dynamic programming process in parallel, resulting in significant speedup. To evaluate the effectiveness of our method, we quantitatively compare the dance motions synthesized by our method with motion synthesis results by several peer methods using the motions captured from professional human dancers' performance as the gold standard. We also conducted several medium-scale user studies to explore how perceptually our dance motion synthesis method can outperform existing methods in synthesizing dance motions to match with a piece of music. These user studies produced very positive results on our music-driven dance motion synthesis experiments for several Asian dance genres, confirming the advantages of our method.

  20. Example-based automatic music-driven conventional dance motion synthesis.

    PubMed

    Fan, Rukun; Xu, Songhua; Geng, Weidong

    2012-03-01

    We introduce a novel method for synthesizing dance motions that follow the emotions and contents of a piece of music. Our method employs a learning-based approach to model the music to motion mapping relationship embodied in example dance motions along with those motions' accompanying background music. A key step in our method is to train a music to motion matching quality rating function through learning the music to motion mapping relationship exhibited in synchronized music and dance motion data, which were captured from professional human dance performance. To generate an optimal sequence of dance motion segments to match with a piece of music, we introduce a constraint-based dynamic programming procedure. This procedure considers both music to motion matching quality and visual smoothness of a resultant dance motion sequence. We also introduce a two-way evaluation strategy, coupled with a GPU-based implementation, through which we can execute the dynamic programming process in parallel, resulting in significant speedup. To evaluate the effectiveness of our method, we quantitatively compare the dance motions synthesized by our method with motion synthesis results by several peer methods using the motions captured from professional human dancers' performance as the gold standard. We also conducted several medium-scale user studies to explore how perceptually our dance motion synthesis method can outperform existing methods in synthesizing dance motions to match with a piece of music. These user studies produced very positive results on our music-driven dance motion synthesis experiments for several Asian dance genres, confirming the advantages of our method.

  1. Adaptive motion artifact reducing algorithm for wrist photoplethysmography application

    NASA Astrophysics Data System (ADS)

    Zhao, Jingwei; Wang, Guijin; Shi, Chenbo

    2016-04-01

    Photoplethysmography (PPG) technology is widely used in wearable heart pulse rate monitoring. It might reveal the potential risks of heart condition and cardiopulmonary function by detecting the cardiac rhythms in physical exercise. However the quality of wrist photoelectric signal is very sensitive to motion artifact since the thicker tissues and the fewer amount of capillaries. Therefore, motion artifact is the major factor that impede the heart rate measurement in the high intensity exercising. One accelerometer and three channels of light with different wavelengths are used in this research to analyze the coupled form of motion artifact. A novel approach is proposed to separate the pulse signal from motion artifact by exploiting their mixing ratio in different optical paths. There are four major steps of our method: preprocessing, motion artifact estimation, adaptive filtering and heart rate calculation. Five healthy young men are participated in the experiment. The speeder in the treadmill is configured as 12km/h, and all subjects would run for 3-10 minutes by swinging the arms naturally. The final result is compared with chest strap. The average of mean square error (MSE) is less than 3 beats per minute (BPM/min). Proposed method performed well in intense physical exercise and shows the great robustness to individuals with different running style and posture.

  2. Pose and motion from contact

    SciTech Connect

    Jia, Y.B.; Erdmann, M.

    1999-05-01

    In the absence of vision, grasping an object often relies on tactile feedback from the fingertips. As the finger pushes the object, the fingertip can feel the contact point move. If the object is known in advance, from this motion the finger may infer the location of the contact point on the object, and thereby, the object pose. This paper primarily investigates the problem of determining the pose (orientation and position) and motion (velocity and angular velocity) of a planar object with known geometry from such contact motion generated by pushing. A dynamic analysis of pushing yields a nonlinear system that relates through contact the object pose and motion to the finger motion. The contact motion on the fingertip thus encodes certain information about the object pose. Nonlinear observability theory is employed to show that such information is sufficient for the finger to observe not only the pose, but also the motion of the object. Therefore, a sensing strategy can be realized as an observer of the nonlinear dynamic system. Two observers are subsequently introduced. The first observer, based on the work of Gautheir, Hammouri, and Othman (1992), has its gain determined by the solution of a Lyapunov-like equation; it can be activated at any time instant during a push. The second observer, based on Newton`s method, solves for the initial (motionless) object pose from three intermediate contact points during a push. Under the Coulomb-friction model, the paper deals with support friction in the plane and/or contact friction between the finger and the object. Extensive simulations have been done to demonstrate the feasibility of the two observers. Preliminary experiments (with an Adept robot) have also been conducted. A contact sensor has been implemented using strain gauges.

  3. Effect of motion cues during complex curved approach and landing tasks: A piloted simulation study

    NASA Technical Reports Server (NTRS)

    Scanlon, Charles H.

    1987-01-01

    A piloted simulation study was conducted to examine the effect of motion cues using a high fidelity simulation of commercial aircraft during the performance of complex approach and landing tasks in the Microwave Landing System (MLS) signal environment. The data from these tests indicate that in a high complexity MLS approach task with moderate turbulence and wind, the pilot uses motion cues to improve path tracking performance. No significant differences in tracking accuracy were noted for the low and medium complexity tasks, regardless of the presence of motion cues. Higher control input rates were measured for all tasks when motion was used. Pilot eye scan, as measured by instrument dwell time, was faster when motion cues were used regardless of the complexity of the approach tasks. Pilot comments indicated a preference for motion. With motion cues, pilots appeared to work harder in all levels of task complexity and to improve tracking performance in the most complex approach task.

  4. Quantitative assessment of human motion using video motion analysis

    NASA Technical Reports Server (NTRS)

    Probe, John D.

    1990-01-01

    In the study of the dynamics and kinematics of the human body, a wide variety of technologies was developed. Photogrammetric techniques are well documented and are known to provide reliable positional data from recorded images. Often these techniques are used in conjunction with cinematography and videography for analysis of planar motion, and to a lesser degree three-dimensional motion. Cinematography has been the most widely used medium for movement analysis. Excessive operating costs and the lag time required for film development coupled with recent advances in video technology have allowed video based motion analysis systems to emerge as a cost effective method of collecting and analyzing human movement. The Anthropometric and Biomechanics Lab at Johnson Space Center utilizes the video based Ariel Performance Analysis System to develop data on shirt-sleeved and space-suited human performance in order to plan efficient on orbit intravehicular and extravehicular activities. The system is described.

  5. Wadaiko performance enhances synchronized motion of mentally disabled persons.

    PubMed

    Mizuno, Eriko; Sakuma, Haruo

    2013-02-01

    People with mental disabilities tend to lack communication skills and have difficulty with interpersonal relationships. Interpersonal communication skills were examined in two people with Down Syndrome with regard to playing wadaiko (Japanese drum). Motion analysis compared single play and two-person play in which one participant was more skillful than the other. The effect of wadaiko play was quantified using two different methodologies: motion delay and hit-timing analysis and visual analog-scale (VAS) ratings before and after play. The motion analysis indicated that the study participants became mutually synchronized in playing wadaiko, and that a participant played more accurately when he played with a senior member. VAS ratings indicated that participants felt more positive after practicing wadaiko than before and self-confidence improved. Synchronized gestures of wadaiko performance may be an effective therapy for people with limited communication skills.

  6. Measurement of pulsatile motion with millisecond resolution by MRI.

    PubMed

    Souchon, Rémi; Gennisson, Jean-Luc; Tanter, Mickael; Salomir, Rares; Chapelon, Jean-Yves; Rouvière, Olivier

    2012-06-01

    We investigated a technique based on phase-contrast cine MRI combined with deconvolution of the phase shift waveforms to measure rapidly varying pulsatile motion waveforms. The technique does not require steady-state displacement during motion encoding. Simulations and experiments were performed in porcine liver samples in view of a specific application, namely the observation of transient displacements induced by acoustic radiation force. Simulations illustrate the advantages and shortcomings of the methods. For experimental validation, the waveforms were acquired with an ultrafast ultrasound scanner (Supersonic Imagine Aixplorer), and the rates of decay of the waveforms (relaxation time) were compared. With bipolar motion-encoding gradient of 8.4 ms, the method was able to measure displacement waveforms with a temporal resolution of 1 ms over a time course of 40 ms. Reasonable agreement was found between the rate of decay of the waveforms measured in ultrasound (2.8 ms) and in MRI (2.7-3.3 ms).

  7. Elements of an improved model of debris‐flow motion

    USGS Publications Warehouse

    Iverson, Richard M.

    2009-01-01

    A new depth‐averaged model of debris‐flow motion describes simultaneous evolution of flow velocity and depth, solid and fluid volume fractions, and pore‐fluid pressure. Non‐hydrostatic pore‐fluid pressure is produced by dilatancy, a state‐dependent property that links the depth‐averaged shear rate and volumetric strain rate of the granular phase. Pore‐pressure changes caused by shearing allow the model to exhibit rate‐dependent flow resistance, despite the fact that the basal shear traction involves only rate‐independent Coulomb friction. An analytical solution of simplified model equations shows that the onset of downslope motion can be accelerated or retarded by pore‐pressure change, contingent on whether dilatancy is positive or negative. A different analytical solution shows that such effects will likely be muted if downslope motion continues long enough, because dilatancy then evolves toward zero, and volume fractions and pore pressure concurrently evolve toward steady states.

  8. Memory bandwidth-scalable motion estimation for mobile video coding

    NASA Astrophysics Data System (ADS)

    Hsieh, Jui-Hung; Tai, Wei-Cheng; Chang, Tian-Sheuan

    2011-12-01

    The heavy memory access of motion estimation (ME) execution consumes significant power and could limit ME execution when the available memory bandwidth (BW) is reduced because of access congestion or changes in the dynamics of the power environment of modern mobile devices. In order to adapt to the changing BW while maintaining the rate-distortion (R-D) performance, this article proposes a novel data BW-scalable algorithm for ME with mobile multimedia chips. The available BW is modeled in a R-D sense and allocated to fit the dynamic contents. The simulation result shows 70% BW savings while keeping equivalent R-D performance compared with H.264 reference software for low-motion CIF-sized video. For high-motion sequences, the result shows our algorithm can better use the available BW to save an average bit rate of up to 13% with up to 0.1-dB PSNR increase for similar BW usage.

  9. Occluded motion alters event perception.

    PubMed

    Kawachi, Yousuke; Gyoba, Jiro

    2013-04-01

    We employed audiovisual stream/bounce displays, in which two moving objects with crossing trajectories are more likely to be perceived as bouncing off, rather than streaming through, each other when a brief sound is presented at the coincidence of the two objects. However, Kawachi and Gyoba (Perception 35:1289-1294, 2006b) reported that the presence of an additional moving object near the two objects altered the perception of a bouncing event to that of a streaming event. In this study, we extended this finding and examined whether alteration of the event perception could be induced by the visual context, such as by occluded object motion near the stream/bounce display. The results demonstrated that even when the sound was presented, the continuous occluded motion strongly biased observers' percepts toward the streaming percept during a short occlusion interval (approximately 100 ms). In contrast, when the continuous occluded motion was disrupted by introducing a spatiotemporal gap in the motion trajectory or by removing occlusion cues such as deletion/accretion, the bias toward the streaming percept declined. Thus, we suggest that a representation of object motion generated under a limited occlusion interval interferes with audiovisual event perception.

  10. 29 CFR 1603.208 - Motions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... procedural matters, the administrative law judge may not grant a written motion prior to the expiration of the time for filing responses. The administrative law judge may deny a written motion without awaiting... filing of a motion does not stay the proceeding. (e) All motions and responses must comply with...

  11. 22 CFR 224.28 - Motions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Motions. 224.28 Section 224.28 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT IMPLEMENTATION OF THE PROGRAM FRAUD CIVIL REMEDIES ACT § 224.28 Motions. (a) Any application to the ALJ for an order or ruling shall be by motion. Motions...

  12. 10 CFR 13.28 - Motions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Motions. 13.28 Section 13.28 Energy NUCLEAR REGULATORY COMMISSION PROGRAM FRAUD CIVIL REMEDIES § 13.28 Motions. (a) Any application to the ALJ for an order or ruling shall be by motion. Motions shall state the relief sought, the authority relied upon, and...

  13. Empirical comparison of a linear and a nonlinear washout for motion simulators

    NASA Technical Reports Server (NTRS)

    Parrish, R. V.; Martin, D. J., Jr.

    1975-01-01

    The subjective opinions gathered from seven pilots in the process of comparing a linear and a nonlinear washout for motion simulators reveal an important advance in motion cue presentation. The advance is not in the increased cue provided by the nonlinear filter over a linear filter for the same amount of motion base travel, but rather in the elimination of false rotational rate cues presented by linear filters.

  14. Types of diaphragmatic motion during hepatic angiography.

    PubMed

    Katsuda, T; Kuroda, C; Fujita, M

    1997-01-01

    To determine the types and causes of diaphragmatic motion during hepatic angiography, the authors used transarterial cut-film portography (TAP) to study movement of the diaphragm during breath-holding. Thirty-three TAP sequences were studied, and the patients' diaphragmatic motions were classified into four categories according to the distance their diaphragms moved. Results showed that the diaphragm was stationary in 33% of the TAP studies, while perpetual motion occurred in 15% of the studies, early-phase motion occurred in 12% and late-phase motion occurred in 40%. Ten sequences showed diaphragmatic motion of more than 10 mm, with eight sequences showing caudal motion and two showing cranial motion. This article discusses the cause of diaphragmatic motion during breath-holding for hepatic angiography and presents suggestions to reduce motion artifacts during the exam.

  15. Recovery of motion parameters from distortions in scanned images

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.

    1997-01-01

    Scanned images, such as those produced by the scanning-laser ophthalmoscope (SLO), show distortions when there is target motion. This is because pixels corresponding to different image regions are acquired sequentially, and so, in essence, are slices of different snapshots. While these distortions create problems for image registration algorithms, they are potentially useful for recovering target motion parameters at temporal frequencies above the frame rate. Stetter, Sendtner and Timberlake measured large distortions in SLO images to recover the time course of rapid horizontal saccadic eye movements. Here, this work is extended with the goal of automatically recovering small eye movements in two dimensions. Eye position during the frame interval is modeled using a low dimensional parametric description, which in turn is used to generate predicted distortions of a reference template. The input image is then registered to the distorted template using normalized cross correlation. The motion parameters are then varied, and the correlation recomputed, to find the motion which maximizes the peak value of the correlation. The location and value of the correlation maximum are determined with sub-pixel precision using biquadratic interpolation, yielding eye position resolution better than 1 arc minute. This method of motion parameter estimation is tested using actual SLO images as well as simulated images. Motion parameter estimation might also be applied to individual video lines in order to reduce pipeline delays for a near real-time system.

  16. Scalable Photogrammetric Motion Capture System "mosca": Development and Application

    NASA Astrophysics Data System (ADS)

    Knyaz, V. A.

    2015-05-01

    Wide variety of applications (from industrial to entertainment) has a need for reliable and accurate 3D information about motion of an object and its parts. Very often the process of movement is rather fast as in cases of vehicle movement, sport biomechanics, animation of cartoon characters. Motion capture systems based on different physical principles are used for these purposes. The great potential for obtaining high accuracy and high degree of automation has vision-based system due to progress in image processing and analysis. Scalable inexpensive motion capture system is developed as a convenient and flexible tool for solving various tasks requiring 3D motion analysis. It is based on photogrammetric techniques of 3D measurements and provides high speed image acquisition, high accuracy of 3D measurements and highly automated processing of captured data. Depending on the application the system can be easily modified for different working areas from 100 mm to 10 m. The developed motion capture system uses from 2 to 4 technical vision cameras for video sequences of object motion acquisition. All cameras work in synchronization mode at frame rate up to 100 frames per second under the control of personal computer providing the possibility for accurate calculation of 3D coordinates of interest points. The system was used for a set of different applications fields and demonstrated high accuracy and high level of automation.

  17. Projected motion group for vision

    NASA Astrophysics Data System (ADS)

    Tanaka, Masaru

    1993-12-01

    For the image understanding and patten recognitions, it is important to extract invariant features from given images corresponding to various transformations. Once the invariant features are obtained, we can estimate motion parameters and/or categorize objects into equivalent classes based on some criterions. So many techniques to extract invariant features are proposed, and most of them need exact matching between an image before transformation and another image after transformation. But this matching process is not easy to perform. Then we propose a group theoretical method, which does not require a matching process. In this paper, we show the bases of the representation of the perspective projected motion group and those of the spherical projected motion group explicitly.

  18. Piezoelectric step-motion actuator

    DOEpatents

    Mentesana; Charles P.

    2006-10-10

    A step-motion actuator using piezoelectric material to launch a flight mass which, in turn, actuates a drive pawl to progressively engage and drive a toothed wheel or rod to accomplish stepped motion. Thus, the piezoelectric material converts electrical energy into kinetic energy of the mass, and the drive pawl and toothed wheel or rod convert the kinetic energy of the mass into the desired rotary or linear stepped motion. A compression frame may be secured about the piezoelectric element and adapted to pre-compress the piezoelectric material so as to reduce tensile loads thereon. A return spring may be used to return the mass to its resting position against the compression frame or piezoelectric material following launch. Alternative embodiment are possible, including an alternative first embodiment wherein two masses are launched in substantially different directions, and an alternative second embodiment wherein the mass is eliminated in favor of the piezoelectric material launching itself.

  19. Cervical Spinal Motion During Orotracheal Intubation.

    DTIC Science & Technology

    1998-01-01

    Sixteen fresh human cadavers were intubated while recording cervical motion using a cine fluoroscopic technique. Segmental cervical motion from the...intubation was performed using no external stabilization, Gardner-Wells traction and manual in-line cervical immobilization. The cadaveric spine motion...immobilization reduced motion at the destabilize C4-5 level. Four patients without significant cervical pathology and normal motion of flexion

  20. A Motion Aftereffect from Visual Imagery of Motion

    ERIC Educational Resources Information Center

    Winawer, Jonathan; Huk, Alexander C.; Boroditsky, Lera

    2010-01-01

    Mental imagery is thought to share properties with perception. To what extent does the process of imagining a scene share neural circuits and computational mechanisms with actually perceiving the same scene? Here, we investigated whether mental imagery of motion in a particular direction recruits neural circuits tuned to the same direction of…

  1. Contribution of Visuospatial and Motion-Tracking to Invisible Motion

    PubMed Central

    Battaglini, Luca; Casco, Clara

    2016-01-01

    People experience an object's motion even when it is occluded. We investigate the processing of invisible motion in three experiments. Observers saw a moving circle passing behind an invisible, irregular hendecagonal polygon and had to respond as quickly as possible when the target had “just reappeared” from behind the occluder. Without explicit cues allowing the end of each of the eight hidden trajectories to be predicted (length ranging between 4.7 and 5 deg), we found as expected, if visuospatial attention was involved, anticipation errors, providing that information on pre-occluder motion was available. This indicates that the observers, rather than simply responding when they saw the target, tended to anticipate its reappearance (Experiment 1). The new finding is that, with a fixation mark indicating the center of the invisible trajectory, a linear relationship between the physical and judged occlusion duration is found, but not without it (Experiment 2) or with a fixation mark varying in position from trial to trial (Experiment 3). We interpret the role of central fixation in the differences in distinguishing trajectories smaller than 0.3 deg, by suggesting that it reflects spatiotemporal computation and motion-tracking. These two mechanisms allow visual imagery to form of the point symmetrical to that of the disappearance, with respect to fixation, and then for the occluded moving target to be tracked up to this point. PMID:27683566

  2. Quantitative assessment of human motion using video motion analysis

    NASA Technical Reports Server (NTRS)

    Probe, John D.

    1993-01-01

    In the study of the dynamics and kinematics of the human body a wide variety of technologies has been developed. Photogrammetric techniques are well documented and are known to provide reliable positional data from recorded images. Often these techniques are used in conjunction with cinematography and videography for analysis of planar motion, and to a lesser degree three-dimensional motion. Cinematography has been the most widely used medium for movement analysis. Excessive operating costs and the lag time required for film development, coupled with recent advances in video technology, have allowed video based motion analysis systems to emerge as a cost effective method of collecting and analyzing human movement. The Anthropometric and Biomechanics Lab at Johnson Space Center utilizes the video based Ariel Performance Analysis System (APAS) to develop data on shirtsleeved and space-suited human performance in order to plan efficient on-orbit intravehicular and extravehicular activities. APAS is a fully integrated system of hardware and software for biomechanics and the analysis of human performance and generalized motion measurement. Major components of the complete system include the video system, the AT compatible computer, and the proprietary software.

  3. A Countermeasure for Space Motion Sickness

    NASA Technical Reports Server (NTRS)

    Reschke, M. F.; Somers, J. T.; Leigh, R. J.; Jones, G. Melvill

    2006-01-01

    the possibility of producing functionally useful adaptation during space flight without the penalty of disabling motion sickness by controlling the rate of the adaptive process by means of an appropriate stroboscopically presented environment. After several recent meetings with Professor Melvill Jones, we were encouraged to repeat the motion sickness portions of his and Mandl's 1981 stroboscopic experiment. In conducting this experiment we used a randomized cross-over design where subjects were randomly assigned to either a stroboscopic flash or no strobe for their first exposure in the experimental design. Twenty subjects (19 subjects completed the study) read a short passage from Treasure Island mounted on the wall approximately 1 m from their eyes while wearing left-right reversing prisms. The strobe on time of 3 microseconds and flash frequency of 4 Hz was set to equal that used in the original study. Motion sickness was scored using a modified Miller and Graybiel scale that we constructed to include symptoms that may be elicited under conditions where reversing prisms are worn. On this scale a score of 5 represented Malaise IIa (mild motion sickness) and a score of 8 or above is approaching frank sickness. Symptoms were tracked and recorded every 5 min during the task. Testing was limited to 30 min unless the subject had reached the MIIa score, at which time the test was terminated. Performance under stroboscopic illumination was significantly better than when the subjects read under normal room illumination while wearing the left-right reversing prisms. Based on these results we developed a goggle system using LCD material that can be strobed. To evaluate the effectiveness of stroboscopic goggles we tested an additional 9 subjects in addition to retesting 10 used in the stroboscopic pilot study described above. These 19 subjects wore a pair of strobing LCD goggles that could be cycled at 4 Hz. These subjects wore the goggles while also wearing left-right reversg

  4. Vertical motion simulator familiarization guide

    NASA Technical Reports Server (NTRS)

    Danek, George L.

    1993-01-01

    The Vertical Motion Simulator Familiarization Guide provides a synoptic description of the Vertical Motion Simulator (VMS) and descriptions of the various simulation components and systems. The intended audience is the community of scientists and engineers who employ the VMS for research and development. The concept of a research simulator system is introduced and the building block nature of the VMS is emphasized. Individual sections describe all the hardware elements in terms of general properties and capabilities. Also included are an example of a typical VMS simulation which graphically illustrates the composition of the system and shows the signal flow among the elements and a glossary of specialized terms, abbreviations, and acronyms.

  5. Motion Analysis From Television Images

    NASA Astrophysics Data System (ADS)

    Silberberg, George G.; Keller, Patrick N.

    1982-02-01

    The Department of Defense ranges have relied on photographic instrumentation for gathering data of firings for all types of ordnance. A large inventory of cameras are available on the market that can be used for these tasks. A new set of optical instrumentation is beginning to appear which, in many cases, can directly replace photographic cameras for a great deal of the work being performed now. These are television cameras modified so they can stop motion, see in the dark, perform under hostile environments, and provide real time information. This paper discusses techniques for modifying television cameras so they can be used for motion analysis.

  6. Testing theories of superluminal motion

    NASA Astrophysics Data System (ADS)

    Scheuer, P. A. G.

    1984-09-01

    Relativistic beaming, so-called Christmas tree, gravitational lens, and noncosmological red shift theories of superluminal motion are reviewed. The impact of QUASAT in tests of relativistic beaming theories is discussed. The QUASAT will be able to resolve, and measure motions in, sources of one to a few hundred millijanskys, whose jets are too short to be resolved with Earth-based VLBI. It can help to resolve such jets by the 3:1 increase in baseline; and by improved dynamic range, which makes the jet observable over a larger number of milliarcsec.

  7. Perception of social interactions for spatially scrambled biological motion.

    PubMed

    Thurman, Steven M; Lu, Hongjing

    2014-01-01

    It is vitally important for humans to detect living creatures in the environment and to analyze their behavior to facilitate action understanding and high-level social inference. The current study employed naturalistic point-light animations to examine the ability of human observers to spontaneously identify and discriminate socially interactive behaviors between two human agents. Specifically, we investigated the importance of global body form, intrinsic joint movements, extrinsic whole-body movements, and critically, the congruency between intrinsic and extrinsic motions. Motion congruency is hypothesized to be particularly important because of the constraint it imposes on naturalistic action due to the inherent causal relationship between limb movements and whole body motion. Using a free response paradigm in Experiment 1, we discovered that many naïve observers (55%) spontaneously attributed animate and/or social traits to spatially-scrambled displays of interpersonal interaction. Total stimulus motion energy was strongly correlated with the likelihood that an observer would attribute animate/social traits, as opposed to physical/mechanical traits, to the scrambled dot stimuli. In Experiment 2, we found that participants could identify interactions between spatially-scrambled displays of human dance as long as congruency was maintained between intrinsic/extrinsic movements. Violating the motion congruency constraint resulted in chance discrimination performance for the spatially-scrambled displays. Finally, Experiment 3 showed that scrambled point-light dancing animations violating this constraint were also rated as significantly less interactive than animations with congruent intrinsic/extrinsic motion. These results demonstrate the importance of intrinsic/extrinsic motion congruency for biological motion analysis, and support a theoretical framework in which early visual filters help to detect animate agents in the environment based on several fundamental

  8. Insights into mechanism kinematics for protein motion simulation

    PubMed Central

    2014-01-01

    Background The high demanding computational requirements necessary to carry out protein motion simulations make it difficult to obtain information related to protein motion. On the one hand, molecular dynamics simulation requires huge computational resources to achieve satisfactory motion simulations. On the other hand, less accurate procedures such as interpolation methods, do not generate realistic morphs from the kinematic point of view. Analyzing a protein’s movement is very similar to serial robots; thus, it is possible to treat the protein chain as a serial mechanism composed of rotational degrees of freedom. Recently, based on this hypothesis, new methodologies have arisen, based on mechanism and robot kinematics, to simulate protein motion. Probabilistic roadmap method, which discretizes the protein configurational space against a scoring function, or the kinetostatic compliance method that minimizes the torques that appear in bonds, aim to simulate protein motion with a reduced computational cost. Results In this paper a new viewpoint for protein motion simulation, based on mechanism kinematics is presented. The paper describes a set of methodologies, combining different techniques such as structure normalization normalization processes, simulation algorithms and secondary structure detection procedures. The combination of all these procedures allows to obtain kinematic morphs of proteins achieving a very good computational cost-error rate, while maintaining the biological meaning of the obtained structures and the kinematic viability of the obtained motion. Conclusions The procedure presented in this paper, implements different modules to perform the simulation of the conformational change suffered by a protein when exerting its function. The combination of a main simulation procedure assisted by a secondary structure process, and a side chain orientation strategy, allows to obtain a fast and reliable simulations of protein motion. PMID:24923224

  9. Alpha motion based on a motion detector, but not on the Müller-Lyer illusion

    NASA Astrophysics Data System (ADS)

    Suzuki, Masahiro

    2014-07-01

    This study examined the mechanism of alpha motion, the apparent motion of the Müller-Lyer figure's shaft that occurs when the arrowheads and arrow tails are alternately presented. The following facts were found: (a) reduced exposure duration decreased the amount of alpha motion, and this phenomenon was not explainable by the amount of the Müller-Lyer illusion; (b) the motion aftereffect occurred after adaptation to alpha motion; (c) occurrence of alpha motion became difficult when the temporal frequency increased, and this characteristic of alpha motion was similar to the characteristic of a motion detector that motion detection became difficult when the temporal frequency increased from the optimal frequency. These findings indicated that alpha motion occurs on the basis of a motion detector but not on the Müller-Lyer illusion, and that the mechanism of alpha motion is the same as that of general motion perception.

  10. Reading and Coherent Motion Perception in School Age Children

    ERIC Educational Resources Information Center

    Kassaliete, Evita; Lacis, Ivars; Fomins, Sergejs; Krumina, Gunta

    2015-01-01

    This study includes an evaluation, according to age, of the reading and global motion perception developmental trajectories of 2027 school age children in typical stages of development. Reading is assessed using the reading rate score test, for which all of the student participants, regardless of age, received the same passage of text of a medium…

  11. Educational Materials and Equipment Company: Collisions and Simple Harmonic Motion.

    ERIC Educational Resources Information Center

    Ritchie, LeVonda S.; Risley, John S.

    1988-01-01

    Reviews a computer courseware package for mechanics at the high school and introductory college level. Discusses one-dimensional collisions, two-dimensional collisions, and simple harmonic motion programs. Shows two typical monitor displays. Rates this program as good overall. (YP)

  12. Pilot-Induced Oscillation Prediction With Three Levels of Simulation Motion Displacement

    NASA Technical Reports Server (NTRS)

    Schroeder, Jeffery A.; Chung, William W. Y.; Tran, Duc T.; Laforce, Soren; Bengford, Norman J.

    2001-01-01

    Simulator motion platform characteristics were examined to determine if the amount of motion affects pilot-induced oscillation (PIO) prediction. Five test pilots evaluated how susceptible 18 different sets of pitch dynamics were to PIOs with three different levels of simulation motion platform displacement: large, small, and none. The pitch dynamics were those of a previous in-flight experiment, some of which elicited PIOs These in-flight results served as truth data for the simulation. As such, the in-flight experiment was replicated as much as possible. Objective and subjective data were collected and analyzed With large motion, PIO and handling qualities ratings matched the flight data more closely than did small motion or no motion. Also, regardless of the aircraft dynamics, large motion increased pilot confidence in assigning handling qualifies ratings, reduced safety pilot trips, and lowered touchdown velocities. While both large and small motion provided a pitch rate cue of high fidelity, only large motion presented the pilot with a high fidelity vertical acceleration cue.

  13. Understanding of hand motion in sentence level using HMM

    NASA Astrophysics Data System (ADS)

    Lee, Boohyung; Han, Youngjoon; Chung, Hwanik; Hahn, Hernsoo

    2004-06-01

    This paper proposes a new method that can recognize a sequence of hand motion expressing a sentence in sign language. Recognition procedure is divided into two steps: separation of the sequence of hand motions into the sub-sequences each of which expresses one word and combination of the words in order to construct a sentence having a meaning. In the first step, sequences of hand motion images are segmented by testing the continuity of the hand motions and by the multiscale image segmentation scheme. The trajectory of the hand motions are estimated by the affine transformation. Each sign in the sentence is represented by the extended chereme analysis model and each chereme is represented by the status vector for determining the transition in the HMM. In the second step, each sentence is also represented by the HMM. The Viterbi algorithm and context-dependent HMM are used to find the best state sequence in the HMM. The proposed algorithm has been tested with ten sequences of images, each of which expresses a sentence in Korean sign language. The experimental results have shown that the proposed algorithm can separate the sentence level image sequence into the word level sub-sequences with the success rate of 75% on average and recognize the sentence with the success rate of 80%.

  14. What Learning to See Arbitrary Motion Tells Us about Biological Motion Perception

    ERIC Educational Resources Information Center

    Hiris, Eric; Krebeck, Aurore; Edmonds, Jennifer; Stout, Alexandra

    2005-01-01

    In separate studies, observers viewed upright biological motion, inverted biological motion, or arbitrary motion created from systematically randomizing the positions of point-light dots. Results showed that observers (a) could learn to detect the presence of arbitrary motion, (b) could not learn to discriminate the coherence of arbitrary motion,…

  15. Influence of Visual Motion, Suggestion, and Illusory Motion on Self-Motion Perception in the Horizontal Plane

    PubMed Central

    Rosenblatt, Steven David; Crane, Benjamin Thomas

    2015-01-01

    A moving visual field can induce the feeling of self-motion or vection. Illusory motion from static repeated asymmetric patterns creates a compelling visual motion stimulus, but it is unclear if such illusory motion can induce a feeling of self-motion or alter self-motion perception. In these experiments, human subjects reported the perceived direction of self-motion for sway translation and yaw rotation at the end of a period of viewing set visual stimuli coordinated with varying inertial stimuli. This tested the hypothesis that illusory visual motion would influence self-motion perception in the horizontal plane. Trials were arranged into 5 blocks based on stimulus type: moving star field with yaw rotation, moving star field with sway translation, illusory motion with yaw, illusory motion with sway, and static arrows with sway. Static arrows were used to evaluate the effect of cognitive suggestion on self-motion perception. Each trial had a control condition; the illusory motion controls were altered versions of the experimental image, which removed the illusory motion effect. For the moving visual stimulus, controls were carried out in a dark room. With the arrow visual stimulus, controls were a gray screen. In blocks containing a visual stimulus there was an 8s viewing interval with the inertial stimulus occurring over the final 1s. This allowed measurement of the visual illusion perception using objective methods. When no visual stimulus was present, only the 1s motion stimulus was presented. Eight women and five men (mean age 37) participated. To assess for a shift in self-motion perception, the effect of each visual stimulus on the self-motion stimulus (cm/s) at which subjects were equally likely to report motion in either direction was measured. Significant effects were seen for moving star fields for both translation (p = 0.001) and rotation (p<0.001), and arrows (p = 0.02). For the visual motion stimuli, inertial motion perception was shifted in the

  16. Strong motion from surface waves in deep sedimentary basins

    USGS Publications Warehouse

    Joyner, W.B.

    2000-01-01

    It is widely recognized that long-period surface waves generated by conversion of body waves at the boundaries of deep sedimentary basins make an important contribution to strong ground motion. The factors controlling the amplitude of such motion, however, are not widely understood. A study of pseudovelocity response spectra of strong-motion records from the Los Angeles Basin shows that late-arriving surface waves with group velocities of about 1 km/sec dominate the ground motion for periods of 3 sec and longer. The rate of amplitude decay for these waves is less than for the body waves and depends significantly on period, with smaller decay for longer periods. The amplitude can be modeled by the equation log y = f(M, RE) + c + bRB where y is the pseudovelocity response, f(M, RE) is an attenuation relation based on a general strong-motion data set, M is moment magnitude, RE is the distance from the source to the edge of the basin, RB is the distance from the edge of the basin to the recording site, and b and c are parameters fit to the data. The equation gives values larger by as much as a factor of 3 than given by the attenuation relationships based on general strong-motion data sets for the same source-site distance. It is clear that surface waves need to be taken into account in the design of long-period structures in deep sedimentary basins. The ground-motion levels specified by the earthquake provisions of current building codes, in California at least, accommodate the long-period ground motions from basin-edge-generated surface waves for periods of 5 sec and less and earthquakes with moment magnitudes of 7.5 or less located more than 20 km outside the basin. There may be problems at longer periods and for earthquakes located closer to the basin edge. The results of this study suggest that anelastic attenuation may need to be included in attempts to model long-period motion in deep sedimentary basins. To obtain better data on surface waves in the future

  17. Smoothing of respiratory motion traces for motion-compensated radiotherapy

    SciTech Connect

    Ernst, Floris; Schlaefer, Alexander; Schweikard, Achim

    2010-01-15

    Purpose: The CyberKnife system has been used successfully for several years to radiosurgically treat tumors without the need for stereotactic fixation or sedation of the patient. It has been shown that tumor motion in the lung, liver, and pancreas can be tracked with acceptable accuracy and repeatability. However, highly precise targeting for tumors in the lower abdomen, especially for tumors which exhibit strong motion, remains problematic. Reasons for this are manifold, like the slow tracking system operating at 26.5 Hz, and using the signal from the tracking camera ''as is''. Since the motion recorded with the camera is used to compensate for system latency by prediction and the predicted signal is subsequently used to infer the tumor position from a correlation model based on x-ray imaging of gold fiducials around the tumor, camera noise directly influences the targeting accuracy. The goal of this work is to establish the suitability of a new smoothing method for respiratory motion traces used in motion-compensated radiotherapy. The authors endeavor to show that better prediction--With a lower rms error of the predicted signal--and/or smoother prediction is possible using this method. Methods: The authors evaluated six commercially available tracking systems (NDI Aurora, PolarisClassic, Polaris Vicra, MicronTracker2 H40, FP5000, and accuTrack compact). The authors first tracked markers both stationary and while in motion to establish the systems' noise characteristics. Then the authors applied a smoothing method based on the a trous wavelet decomposition to reduce the devices' noise level. Additionally, the smoothed signal of the moving target and a motion trace from actual human respiratory motion were subjected to prediction using the MULIN and the nLMS{sub 2} algorithms. Results: The authors established that the noise distribution for a static target is Gaussian and that when the probe is moved such as to mimic human respiration, it remains Gaussian with the

  18. Novice Rules for Projectile Motion.

    ERIC Educational Resources Information Center

    Maloney, David P.

    1988-01-01

    Investigates several aspects of undergraduate students' rules for projectile motion including general patterns; rules for questions about time, distance, solids and liquids; and changes in rules when asked to ignore air resistance. Reports approach differences by sex and high school physics experience, and that novice rules are situation…

  19. STRV Cryocooler Tip Motion Suppression

    NASA Technical Reports Server (NTRS)

    Glaser, R.; Ross, R. G., Jr.; Johnson, D. L.

    1994-01-01

    The Space Technology Research Vehicle (STRV-1b) scheduled to fly at the beginning of June 1994, has a cryocooler vibration suppression experiment aboard doing motion suppression of the tip of the coldfinger. STRV-1b is a bread box sized satellite to be launched on the next flight of the Ariane-4.

  20. How Does Force Affect Motion?

    ERIC Educational Resources Information Center

    Darling, Gerald

    2012-01-01

    Whether playing soccer at recess, walking to lunch, or sitting at their desk, children encounter forces every moment of their lives. The connection between force and motion is absolutely amazing to children, so anyone working with them better be prepared for the battery of tough questions they ask: "What made the ball move that way? Why does a…

  1. Faraday's Law and Seawater Motion

    ERIC Educational Resources Information Center

    De Luca, R.

    2010-01-01

    Using Faraday's law, one can illustrate how an electromotive force generator, directly utilizing seawater motion, works. The conceptual device proposed is rather simple in its components and can be built in any high school or college laboratory. The description of the way in which the device generates an electromotive force can be instructive not…

  2. Tropical Cyclone Structure and Motion

    DTIC Science & Technology

    2016-06-07

    that motion and structure changes occur. Specific interactions being studied are with mesoscale convective systems (MCS) that have been hypothesized...of physical complexity included in current mesoscale models allows detailed examination of environmental and mesoscale convective system (MCS) impacts...model experiments. WORK COMPLETED Simulations using the PSU/NCAR mesoscale model investigated the possible role of mesoscale convective systems in

  3. Projectile Motion Gets the Hose

    ERIC Educational Resources Information Center

    Goff, John Eric; Liyanage, Chinthaka

    2011-01-01

    Students take a weekly quiz in our introductory physics course. During the week in which material focused on projectile motion, we not-so-subtly suggested what problem the students would see on the quiz. The quiz problem was an almost exact replica of a homework problem we worked through in the class preceding the quiz. The goal of the problem is…

  4. Estimating Motion From MRI Data

    PubMed Central

    OZTURK, CENGIZHAN; DERBYSHIRE, J. ANDREW; MCVEIGH, ELLIOT R.

    2007-01-01

    Invited Paper Magnetic resonance imaging (MRI) is an ideal imaging modality to measure blood flow and tissue motion. It provides excellent contrast between soft tissues, and images can be acquired at positions and orientations freely defined by the user. From a temporal sequence of MR images, boundaries and edges of tissues can be tracked by image processing techniques. Additionally, MRI permits the source of the image signal to be manipulated. For example, temporary magnetic tags displaying a pattern of variable brightness may be placed in the object using MR saturation techniques, giving the user a known pattern to detect for motion tracking. The MRI signal is a modulated complex quantity, being derived from a rotating magnetic field in the form of an induced current. Well-defined patterns can also be introduced into the phase of the magnetization, and could be thought of as generalized tags. If the phase of each pixel is preserved during image reconstruction, relative phase shifts can be used to directly encode displacement, velocity and acceleration. New methods for modeling motion fields from MRI have now found application in cardiovascular and other soft tissue imaging. In this review, we shall describe the methods used for encoding, imaging, and modeling motion fields with MRI. PMID:18958181

  5. Physiology of motion sickness symptoms

    NASA Technical Reports Server (NTRS)

    Harm, Deborah L.

    1990-01-01

    Motion sickness research is reviewed with the emphasis placed on theories developed to explain its symptomatology. A general review of central nervous system, autonomic nervous system, and neuroendocrine system involvement in the syndrome. Particular attention is given to signs, symptoms, and physiological correlates, methodological issues, and directions for future research based on a dynamic interactive systems model.

  6. Radiation camera motion correction system

    DOEpatents

    Hoffer, P.B.

    1973-12-18

    The device determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion. (Official Gazette)

  7. Pendulum Motion and Differential Equations

    ERIC Educational Resources Information Center

    Reid, Thomas F.; King, Stephen C.

    2009-01-01

    A common example of real-world motion that can be modeled by a differential equation, and one easily understood by the student, is the simple pendulum. Simplifying assumptions are necessary for closed-form solutions to exist, and frequently there is little discussion of the impact if those assumptions are not met. This article presents a…

  8. Oculometric indices of simulator and aircraft motion

    NASA Technical Reports Server (NTRS)

    Comstock, J. R.

    1984-01-01

    The effects on eye scan behavior of both simulator and aircraft motion and sensitivity of an oculometric measure to motion effects was demonstrated. It was found that fixation time is sensitive to motion effects. Differences between simulator motion and no motion conditions during a series of simulated ILS approaches were studied. The mean fixation time for the no motion condition was found to be significantly longer than for the motion conditions. Eye scan parameters based on data collected in flight, and in fixed base simulation were investigated. Motion effects were evident when the subject was viewing a display supplying attitude and flight path information. The nature of the information provided by motion was examined. The mean fixation times for the no motion condition were significantly longer than for either motion condition, while the two motion conditions did not differ. It is shown that motion serves an alerting function, providing a cue or clue to the pilot that something happened. It is suggested that simulation without motion cues may represent an understatement of the true capacity of the pilot.

  9. Passenger comfort response times as a function of aircraft motion

    NASA Technical Reports Server (NTRS)

    Rinalducci, E. J.

    1975-01-01

    The relationship between a passenger's response time of changes in level of comfort experienced as a function of aircraft motion was examined. The aircraft used in this investigation was capable of providing a wide range of vertical and transverse accelerations by means of direct lift flap control surfaces and side force generator surfaces in addition to normal control surfaces. Response times to changes in comfort were recorded along with the passenger's rating of comfort on a five point scale. In addition, a number of aircraft motion variables including vertical and transverse accelerations were also recorded. Results indicate some relationship between human comfort response times to reaction time data.

  10. Programming Directed Motion on the Micron Scale by Thermal Ratcheting

    NASA Astrophysics Data System (ADS)

    Gehrels, Emily W.; Rogers, W. Benjamin; Zeravcic, Zorana; Manoharan, Vinothan N.

    2015-03-01

    We present an experimental system of DNA-functionalized colloidal particles which exhibit directed motion (``dancing'') along patterned substrates in response to temperature cycling. We take advantage of toehold exchange in the design of the DNA sequences that mediate the colloidal interactions to produce broadened, flat, or even re-entrant binding and unbinding transitions between the particles and substrate. Using this new freedom of design, we devise systems where, by thermal ratcheting, we can externally control the direction of motion and sequence of steps of the colloidal dancer. We determine the maximum work that the system can perform by measuring a maximum average velocity as a function of the thermal ratcheting rate.

  11. Visible light communication based motion detection.

    PubMed

    Sewaiwar, Atul; Tiwari, Samrat Vikramaditya; Chung, Yeon-Ho

    2015-07-13

    In this paper, a unique and novel visible light communication based motion detection is presented. The proposed motion detection is performed based on white light LEDs and an array of photodetectors from existing visible light communication (VLC) links, thus providing VLC with three functionalities of illumination, communication and motion detection. The motion is detected by observing the pattern created by intentional obstruction of the VLC link. Experimental and simulation results demonstrate the validity of the proposed VLC based motion detection technique. The VLC based motion detection can benefit smart devices control in VLC based smart home environments.

  12. Human heading estimation during visually simulated curvilinear motion

    NASA Technical Reports Server (NTRS)

    Stone, L. S.; Perrone, J. A.

    1997-01-01

    Recent studies have suggested that humans cannot estimate their direction of forward translation (heading) from the resulting retinal motion (flow field) alone when rotation rates are higher than approximately 1 deg/sec. It has been argued that either oculomotor or static depth cues are necessary to disambiguate the rotational and translational components of the flow field and, thus, to support accurate heading estimation. We have re-examined this issue using visually simulated motion along a curved path towards a layout of random points as the stimulus. Our data show that, in this curvilinear motion paradigm, five of six observers could estimate their heading relatively accurately and precisely (error and uncertainty < approximately 4 deg), even for rotation rates as high as 16 deg/sec, without the benefit of either oculomotor or static depth cues signaling rotation rate. Such performance is inconsistent with models of human self-motion estimation that require rotation information from sources other than the flow field to cancel the rotational flow.

  13. Assessing Motion Induced Interruptions Using a Motion Platform

    DTIC Science & Technology

    2013-09-01

    same way that cars have shock absorbers to decrease jolt from potholes and bumps in the road, ships may have the potential to be designed to better...Integration (HSI) seeks to assure human performance to reduce operating costs. This thesis seeks to develop a model for ship design in relation to Motion...Induced Interruptions (MII). The model is based on the premise that MIIs affect specific domains of HSI in an adverse way. Future ship design

  14. Acceleration and motion-correction techniques for high-resolution intravascular MRI

    PubMed Central

    Hegde, Shashank Sathyanarayana; Zhang, Yi; Bottomley, Paul A.

    2014-01-01

    Purpose High-resolution intravascular (IV) MRI is susceptible to degradation from physiological motion and requires high frame-rates for true endoscopy. Traditional cardiac-gating techniques compromise efficiency by reducing the effective scan rate. Here we test whether compressed sensing (CS) reconstruction and ungated motion-compensation employing projection shifting, could provide faster motion-suppressed, IVMRI. Theory and Methods CS reconstruction is developed for under-sampled Cartesian and radial imaging using a new IVMRI-specific cost function to effectively increase imaging speed. A new motion correction method is presented wherein individual IVMRI projections are shifted based on the IVMRI detector's intrinsic amplitude and phase properties. The methods are tested at 3T in fruit, human vessel specimens, and a rabbit aorta in vivo. Images are compared using Structural-Similarity and ‘Spokal-Variation’ indices. Results Although some residual artifacts persisted, CS acceleration and radial motion compensation strategies reduced motion artefact in vitro and in vivo, allowing effective accelerations of up to eightfold at 200-300μm resolution. Conclusion 3T IVMRI detectors are well-suited to CS and motion correction strategies based on their intrinsic radially-sparse sensitivity profiles and high signal-to-noise ratios. While benefits of faster free-breathing high-resolution IVMRI and reduced motion sensitivity are realized, there are costs to spatial resolution, and some motion artifacts may persist. PMID:25163750

  15. Two-character motion analysis and synthesis.

    PubMed

    Kwon, Taesoo; Cho, Young-Sang; Park, Sang Il; Shin, Sung Yong

    2008-01-01

    In this paper, we deal with the problem of synthesizing novel motions of standing-up martial arts such as Kickboxing, Karate, and Taekwondo performed by a pair of human-like characters while reflecting their interactions. Adopting an example-based paradigm, we address three non-trivial issues embedded in this problem: motion modeling, interaction modeling, and motion synthesis. For the first issue, we present a semi-automatic motion labeling scheme based on force-based motion segmentation and learning-based action classification. We also construct a pair of motion transition graphs each of which represents an individual motion stream. For the second issue, we propose a scheme for capturing the interactions between two players. A dynamic Bayesian network is adopted to build a motion transition model on top of the coupled motion transition graph that is constructed from an example motion stream. For the last issue, we provide a scheme for synthesizing a novel sequence of coupled motions, guided by the motion transition model. Although the focus of the present work is on martial arts, we believe that the framework of the proposed approach can be conveyed to other two-player motions as well.

  16. Coherence analysis for movement disorder motion captured by six degree-of-freedom inertial sensing

    NASA Astrophysics Data System (ADS)

    Teskey, Wesley J. E.; Elhabiby, Mohamed; El-Sheimy, Naser; MacIntosh, Brian

    2012-06-01

    The use of inertial sensors (accelerometer and gyroscopes) for evaluation of movement disorder motion, including essential tremor (ET) and Parkinson's disease (PD), is becoming prevalent. This paper uses a novel combination of six degree-of-freedom motion analysis and coherence based processing methodologies to uncover differences in the signature of motion for the ET and PD movement disorders. This is the first analysis of such motions utilizing the novel methodology outlined, and it displays a distinct motion profile differentiating between these two groups. Such an analysis can be used to assist medical professionals in diagnosing movement disorders given a currently high error rate of diagnosis. As well, the Kalman smoothing analysis performed in this paper can be quite useful for any application when tracking of human motion is required. Another contribution of the work is the use of wavelets in zero phase lag filtering, which helped in preparing the data for analysis by removing unwanted frequencies without introducing distortions into the data.

  17. Marker-less multi-frame motion tracking and compensation in PET-brain imaging

    NASA Astrophysics Data System (ADS)

    Lindsay, C.; Mukherjee, J. M.; Johnson, K.; Olivier, P.; Song, X.; Shao, L.; King, M. A.

    2015-03-01

    In PET brain imaging, patient motion can contribute significantly to the degradation of image quality potentially leading to diagnostic and therapeutic problems. To mitigate the image artifacts resulting from patient motion, motion must be detected and tracked then provided to a motion correction algorithm. Existing techniques to track patient motion fall into one of two categories: 1) image-derived approaches and 2) external motion tracking (EMT). Typical EMT requires patients to have markers in a known pattern on a rigid too attached to their head, which are then tracked by expensive and bulky motion tracking camera systems or stereo cameras. This has made marker-based EMT unattractive for routine clinical application. Our main contributions are the development of a marker-less motion tracking system that uses lowcost, small depth-sensing cameras which can be installed in the bore of the imaging system. Our motion tracking system does not require anything to be attached to the patient and can track the rigid transformation (6-degrees of freedom) of the patient's head at a rate 60 Hz. We show that our method can not only be used in with Multi-frame Acquisition (MAF) PET motion correction, but precise timing can be employed to determine only the necessary frames needed for correction. This can speeds up reconstruction by eliminating the unnecessary subdivision of frames.

  18. Discriminative analysis of lip motion features for speaker identification and speech-reading.

    PubMed

    Cetingül, H Ertan; Yemez, Yücel; Erzin, Engin; Tekalp, A Murat

    2006-10-01

    There have been several studies that jointly use audio, lip intensity, and lip geometry information for speaker identification and speech-reading applications. This paper proposes using explicit lip motion information, instead of or in addition to lip intensity and/or geometry information, for speaker identification and speech-reading within a unified feature selection and discrimination analysis framework, and addresses two important issues: 1) Is using explicit lip motion information useful, and, 2) if so, what are the best lip motion features for these two applications? The best lip motion features for speaker identification are considered to be those that result in the highest discrimination of individual speakers in a population, whereas for speech-reading, the best features are those providing the highest phoneme/word/phrase recognition rate. Several lip motion feature candidates have been considered including dense motion features within a bounding box about the lip, lip contour motion features, and combination of these with lip shape features. Furthermore, a novel two-stage, spatial, and temporal discrimination analysis is introduced to select the best lip motion features for speaker identification and speech-reading applications. Experimental results using an hidden-Markov-model-based recognition system indicate that using explicit lip motion information provides additional performance gains in both applications, and lip motion features prove more valuable in the case of speech-reading application.

  19. Postural activity and motion sickness during video game play in children and adults.

    PubMed

    Chang, Chih-Hui; Pan, Wu-Wen; Tseng, Li-Ya; Stoffregen, Thomas A

    2012-03-01

    Research has confirmed that console video games give rise to motion sickness in many adults. During exposure to console video games, there are differences in postural activity (movement of the head and torso) between participants who later experience motion sickness and those who do not, confirming a prediction of the postural instability theory of motion sickness. Previous research has not addressed relations between video games, movement and motion sickness in children. We evaluated the nauseogenic properties of a commercially available console video game in both adults and 10-year-old children. Individuals played the game for up to 50 min and were instructed to discontinue immediately if they experienced any symptoms of motion sickness, however mild. During game play, we monitored movement of the head and torso. Motion sickness was reported by 67% of adults and by 56% of children; these rates did not differ. As a group, children moved more than adults. Across age groups, the positional variability of the head and torso increased over time during game play. In addition, we found differences in movement between participants who later reported motion sickness and those who did not. Some of these differences were general across age groups but we also found significant differences between the movement of adults and children who later reported motion sickness. The results confirm that console video games can induce motion sickness in children and demonstrate that changes in postural activity precede the onset of subjective symptoms of motion sickness in children.

  20. Oscillatory motion of sheared nanorods beyond the nematic phase.

    PubMed

    Strehober, David A; Engel, Harald; Klapp, Sabine H L

    2013-07-01

    We study the role of the control parameter triggering nematic order (temperature or concentration) on the dynamical behavior of a system of nanorods under shear. Our study is based on a set of mesoscopic equations of motion for the components of the tensorial orientational order parameter. We investigate these equations via a systematic bifurcation analysis based on a numerical continuation technique, focusing on spatially homogeneous states. Exploring a wide range of parameters we find, unexpectedly, that states with oscillatory motion can exist even under conditions where the equilibrium system is isotropic. These oscillatory states are characterized by a wagging motion of the paranematic director, and they occur if the tumbling parameter is sufficiently small. We also present full nonequilibrium phase diagrams in the plane spanned by the concentration and the shear rate.

  1. Motion sickness elicited by passive rotation in squirrel monkeys

    NASA Technical Reports Server (NTRS)

    Daunton, Nancy G.; Fox, Robert A.

    1991-01-01

    Current theory and recent evidence suggest that motion sickness occurs under conditions of sensory input in which the normal motor programs for producing eye, head, and body movements are not functionally effective, i.e. under conditions in which there are difficulties in maintaining posture and controlling eye movements. Conditions involving conflicting or inconsistent visual-vestibular (VV) stimulation should thus result in greater sickness rates since the existing motor programs do not produce effective control of eye-head-body movements under such conditions. It is felt that the relationship of postural control to motion sickness is an important one and one often overlooked. The results are reported which showed that when postural requirements were minimized by fully restraining squirrel monkeys during hypogravity parabolic flight, no animals became motion sick, but over 80 percent of the same 11 animals became sick if they were unrestrained and maintained control of their posture.

  2. Microgravity and its effects on residual motions in fluids

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan D.; Lundquist, Charles A.

    1990-01-01

    The primary reason for conducting many materials science experiments in space is to minimize or eliminate undesirable effects that might result owing to convective motions in fluids that are driven by buoyancy effects. Of particular concern are the low frequency accelerations caused by the Earth's gravity gradient field, spacecraft attitude motions, and atmospheric drag. In order to gain a limited understanding of the effects of these accelerations, researchers calculated the Stokes' motion of a spherical particle in a fluid for various types of spacecraft attitudes. Researchers assessed the effect of slowly rotating the experimental system relative to the spacecraft in order to reduce the rate at which the particles accumulate against the container wall.

  3. Scalable sensing electronics towards a motion capture suit

    NASA Astrophysics Data System (ADS)

    Xu, Daniel; Gisby, Todd A.; Xie, Shane; Anderson, Iain A.

    2013-04-01

    Being able to accurately record body motion allows complex movements to be characterised and studied. This is especially important in the film or sport coaching industry. Unfortunately, the human body has over 600 skeletal muscles, giving rise to multiple degrees of freedom. In order to accurately capture motion such as hand gestures, elbow or knee flexion and extension, vast numbers of sensors are required. Dielectric elastomer (DE) sensors are an emerging class of electroactive polymer (EAP) that is soft, lightweight and compliant. These characteristics are ideal for a motion capture suit. One challenge is to design sensing electronics that can simultaneously measure multiple sensors. This paper describes a scalable capacitive sensing device that can measure up to 8 different sensors with an update rate of 20Hz.

  4. Master equation for collective spontaneous emission with quantized atomic motion

    NASA Astrophysics Data System (ADS)

    Damanet, François; Braun, Daniel; Martin, John

    2016-02-01

    We derive a Markovian master equation for the internal dynamics of an ensemble of two-level atoms including all effects related to the quantization of their motion. Our equation provides a unifying picture of the consequences of recoil and indistinguishability of atoms beyond the Lamb-Dicke regime on both their dissipative and conservative dynamics, and applies equally well to distinguishable and indistinguishable atoms. We give general expressions for the decay rates and the dipole-dipole shifts for any motional states, and we find closed-form formulas for a number of relevant states (Gaussian states, Fock states, and thermal states). In particular, we show that dipole-dipole interactions and cooperative photon emission can be modulated through the external state of motion.

  5. Supra-threshold Asymmetries in Human Motion Perception

    PubMed Central

    Roditi, Rachel E.; Crane, Benjamin T.

    2012-01-01

    Detection of asymmetries has been a mainstay of using vestibular reflexes to assess semicircular canal function. However, there has been relatively little work on how vestibular stimuli are perceived. Suprathreshold vestibular perception was measured in 13 normal healthy controls by having them compare the relative sizes of two yaw (vertical-axis rotation) or sway (right-left translation) stimuli. Both stimuli were 1.5 s in duration with a staircase used to adjust the relative size of the stimuli to find a pair of stimuli perceived as equal. Motion stimuli were delivered in darkness using a hexapod motion platform, and visual stimuli simulating motion were presented on a screen in the absence of platform motion. Both same direction (SD) and opposite direction (OD) stimuli were delivered in separate runs. After a two-interval stimulus, subjects reported which movement they perceived as larger. Cumulative distribution functions were fit to the responses so that the relative magnitudes of the two stimuli perceived as equal could be determined. For OD trial blocks, a directional asymmetry index (DAI) was calculated to compare the relative size of perceived rightward and leftward motion. For all trial blocks, a temporal asymmetry index (TAI) was used to compare the relative size of the first and second intervals. Motion OD stimuli were perceived as equal in all subjects in yaw and all but one in sway. For visual OD stimuli, two subjects had slightly asymmetric responses for both sway and yaw. The TAI demonstrated asymmetry in 54% in yaw, in which the second interval was perceived to be larger in all but one subject who had an asymmetry. For sway, only two subjects had a significant asymmetry. Visual stimuli produced a similar rate of asymmetry. The direction and magnitude of these asymmetries were not significantly correlated with those seen for motion stimuli. Asymmetries were found in a fraction with the TAI in SD stimuli for motion in yaw (42%) and sway (33%), as

  6. Deficient biological motion perception in schizophrenia: results from a motion noise paradigm

    PubMed Central

    Kim, Jejoong; Norton, Daniel; McBain, Ryan; Ongur, Dost; Chen, Yue

    2013-01-01

    Background: Schizophrenia patients exhibit deficient processing of perceptual and cognitive information. However, it is not well-understood how basic perceptual deficits contribute to higher level cognitive problems in this mental disorder. Perception of biological motion, a motion-based cognitive recognition task, relies on both basic visual motion processing and social cognitive processing, thus providing a useful paradigm to evaluate the potentially hierarchical relationship between these two levels of information processing. Methods: In this study, we designed a biological motion paradigm in which basic visual motion signals were manipulated systematically by incorporating different levels of motion noise. We measured the performances of schizophrenia patients (n = 21) and healthy controls (n = 22) in this biological motion perception task, as well as in coherent motion detection, theory of mind, and a widely used biological motion recognition task. Results: Schizophrenia patients performed the biological motion perception task with significantly lower accuracy than healthy controls when perceptual signals were moderately degraded by noise. A more substantial degradation of perceptual signals, through using additional noise, impaired biological motion perception in both groups. Performance levels on biological motion recognition, coherent motion detection and theory of mind tasks were also reduced in patients. Conclusion: The results from the motion-noise biological motion paradigm indicate that in the presence of visual motion noise, the processing of biological motion information in schizophrenia is deficient. Combined with the results of poor basic visual motion perception (coherent motion task) and biological motion recognition, the association between basic motion signals and biological motion perception suggests a need to incorporate the improvement of visual motion perception in social cognitive remediation. PMID:23847566

  7. Decisions in motion: passive body acceleration modulates hand choice.

    PubMed

    Bakker, Romy S; Weijer, Roel H A; van Beers, Robert J; Selen, Luc P J; Medendorp, W Pieter

    2017-03-01

    In everyday life, we frequently have to decide which hand to use for a certain action. It has been suggested that for this decision the brain calculates expected costs based on action values, such as expected biomechanical costs, expected success rate, handedness and skillfulness. While these conclusions were based on experiments in stationary subjects, we often act while the body is in motion. We investigated how hand choice is affected by passive body motion, which directly affects the biomechanical costs of the arm movement due to its inertia. Using a linear motion platform, twelve right-handed subjects were sinusoidally translated (0.625Hz and 0.5Hz). At eight possible motion phases, they had to reach using either their left or right hand to a target presented at one of eleven possible locations. We predicted hand choice by calculating the expected biomechanical costs under different assumptions about the future acceleration involved in these computations, being the forthcoming acceleration during the reach, the instantaneous acceleration at target onset or zero acceleration as if the body is stationary. While hand choice was generally biased to using the dominant hand, it also modulated sinusoidally with the motion, with the amplitude of the bias depending on the motion's peak acceleration. The phase of hand choice modulation was consistent with the cost model that took the instantaneous acceleration signal at target onset. This suggest that the brain relies on the bottom-up acceleration signals, and not on predictions about future accelerations, when deciding on hand choice during passive whole-body motion.

  8. Mobile user identity sensing using the motion sensor

    NASA Astrophysics Data System (ADS)

    Zhao, Xi; Feng, Tao; Xu, Lei; Shi, Weidong

    2014-05-01

    Employing mobile sensor data to recognize user behavioral activities has been well studied in recent years. However, to adopt the data as a biometric modality has rarely been explored. Existing methods either used the data to recognize gait, which is considered as a distinguished identity feature; or segmented a specific kind of motion for user recognition, such as phone picking-up motion. Since the identity and the motion gesture jointly affect motion data, to fix the gesture (walking or phone picking-up) definitively simplifies the identity sensing problem. However, it meanwhile introduces the complexity from gesture detection or requirement on a higher sample rate from motion sensor readings, which may draw the battery fast and affect the usability of the phone. In general, it is still under investigation that motion based user authentication in a large scale satisfies the accuracy requirement as a stand-alone biometrics modality. In this paper, we propose a novel approach to use the motion sensor readings for user identity sensing. Instead of decoupling the user identity from a gesture, we reasonably assume users have their own distinguishing phone usage habits and extract the identity from fuzzy activity patterns, represented by a combination of body movements whose signals in chains span in relative low frequency spectrum and hand movements whose signals span in relative high frequency spectrum. Then Bayesian Rules are applied to analyze the dependency of different frequency components in the signals. During testing, a posterior probability of user identity given the observed chains can be computed for authentication. Tested on an accelerometer dataset with 347 users, our approach has demonstrated the promising results.

  9. Motion-Adaptive Depth Superresolution.

    PubMed

    Kamilov, Ulugbek S; Boufounos, Petros T

    2017-04-01

    Multi-modal sensing is increasingly becoming important in a number of applications, providing new capabilities and processing challenges. In this paper, we explore the benefit of combining a low-resolution depth sensor with a high-resolution optical video sensor, in order to provide a high-resolution depth map of the scene. We propose a new formulation that is able to incorporate temporal information and exploit the motion of objects in the video to significantly improve the results over existing methods. In particular, our approach exploits the space-time redundancy in the depth and intensity using motion-adaptive low-rank regularization. We provide experiments to validate our approach and confirm that the quality of the estimated high-resolution depth is improved substantially. Our approach can be a first component in systems using vision techniques that rely on high-resolution depth information.

  10. Molecular Motion and Confined Polymers

    NASA Astrophysics Data System (ADS)

    Dobrynin, Andrey V.; Jeon, Junhwan

    2004-03-01

    Microorganisms such as myxobacteria, cyanobacteria, and flexibacteria move by gliding. The gliding has been described by two quite different mechanisms: social (S) motility and adventurous (A) motility. Though retraction of type 4-pili provides the force for the S motility, extrusion of slime, which may be associated with the A motility, is not well known. Nozzle-like structures recently found in cyanobacteria can support the A motility. However, complete understaning A motility is still lacking. To describe the A motility, we use molecular dynamics simulations of a polymer growing inside a cylindrically shaped tube with one end capped. Confined polymers provide a driving force for a tube motion as if a rocket flew with emitting gas. It is seen from the mean-squared displacement of a tube that its motion is ballistic under constant applied force.

  11. Motion magnification for endoscopic surgery

    NASA Astrophysics Data System (ADS)

    McLeod, A. Jonathan; Baxter, John S. H.; de Ribaupierre, Sandrine; Peters, Terry M.

    2014-03-01

    Endoscopic and laparoscopic surgeries are used for many minimally invasive procedures but limit the visual and haptic feedback available to the surgeon. This can make vessel sparing procedures particularly challenging to perform. Previous approaches have focused on hardware intensive intraoperative imaging or augmented reality systems that are difficult to integrate into the operating room. This paper presents a simple approach in which motion is visually enhanced in the endoscopic video to reveal pulsating arteries. This is accomplished by amplifying subtle, periodic changes in intensity coinciding with the patient's pulse. This method is then applied to two procedures to illustrate its potential. The first, endoscopic third ventriculostomy, is a neurosurgical procedure where the floor of the third ventricle must be fenestrated without injury to the basilar artery. The second, nerve-sparing robotic prostatectomy, involves removing the prostate while limiting damage to the neurovascular bundles. In both procedures, motion magnification can enhance subtle pulsation in these structures to aid in identifying and avoiding them.

  12. Interferometric measurement of angular motion

    NASA Astrophysics Data System (ADS)

    Peña Arellano, Fabián Erasmo; Panjwani, Hasnain; Carbone, Ludovico; Speake, Clive C.

    2013-04-01

    This paper describes the design and realization of a homodyne polarization interferometer for measuring angular motion. The optical layout incorporates carefully designed cat's eye retroreflectors that maximize the measurable range of angular motion and facilitate initial alignment. The retroreflectors are optimized and numerically characterized in terms of defocus and spherical aberrations using Zemax software for optical design. The linearity of the measurement is then calculated in terms of the aberrations. The actual physical interferometer is realized as a compact device with optical components from stock and without relying on adjustable holders. Evaluation of its performance using a commercial autocollimator confirmed a reproducibility within 0.1%, a non-linearity of less than 1 ppm with respect to the autocollimator, an upper limit to its sensitivity of about 5 × 10-11 rad/sqrt{textrm {Hz}} from audioband down to 100 mHz and an angular measurement range of more than ±1°.

  13. Motion vision for mobile robots

    NASA Astrophysics Data System (ADS)

    Herrb, Matthieu

    The problem of using computer vision in mobile robots is dealt with. The datacube specialized cards and a parallel machine using a transputer network are studied. The tracking and localization of a three dimensional object in a sequence of images is examined, using first order prediction of the motion in the image plane and verification by a maximal clique search in the graph of mutually compatible matchings. A dynamic environment modeling module, using numerical fusion between trinocular stereovision and tracking of stereo matched primitives is presented. The integration of this perception system in the control architecture of a mobile robot is examined to achieve various functions, such as vision servo motion and environment modeling. The functional units implementing vision tasks and the data exchanged with other units are outlined. Experiments realized with the mobile robot Hilare 1.5 allowed the proposed algorithms and concepts to be validated.

  14. Perpetual Motion with Maxwell's Demon

    NASA Astrophysics Data System (ADS)

    Gordon, Lyndsay G. M.

    2002-11-01

    A method for producing a temperature gradient by Brownian motion in an equilibrated isolated system composed of two fluid compartments and a separating adiabatic membrane is discussed. This method requires globular protein molecules, partially embedded in the membrane, to alternate between two conformations which lie on opposite sides of the membrane. The greater part of each conformer is bathed by one of the fluids and rotates in Brownian motion around its axis, perpendicular to the membrane. Rotational energy is transferred through the membrane during conformational changes. Angular momentum is conserved during the transitions. The energy flow becomes asymmetrical when the conformational changes of the protein are sterically hindered by two of its side-chains, the positions of which are affected by the angular velocity of the rotor. The heat flow increases the temperature gradient in contravention of the Second Law. A second hypothetical model which illustrates solute transfer at variance with the Second Law is also discussed.

  15. Spherical shell model description of rotational motion

    NASA Astrophysics Data System (ADS)

    Zuker, A. P.; Retamosa, J.; Poves, A.; Caurier, E.

    1995-10-01

    Exact diagonalizations with a realistic interaction show that configurations with four neutrons in a major shell and four protons in another-or the same-major shell, behave systematically as backbending rotors. The dominance of the q.q component of the interaction is related to an approximate ``quasi-SU3'' symmetry. It is suggested that the onset of rotational motion in the rare earth nuclei is due to the promotion of the eight particle blocks to the major shells above the ones currently filling. Assuming a ``pseudo-SU3'' coupling for the particles in the lower orbits, it is possible to account remarkably well for the observed B(E2) rates at the beginning of the region.

  16. Wall motion estimation in intracranial aneurysms.

    PubMed

    Oubel, E; Cebral, J R; De Craene, M; Blanc, R; Blasco, J; Macho, J; Putman, C M; Frangi, A F

    2010-09-01

    The quantification of wall motion in cerebral aneurysms is becoming important owing to its potential connection to rupture, and as a way to incorporate the effects of vascular compliance in computational fluid dynamics simulations. Most of papers report values obtained with experimental phantoms, simulated images or animal models, but the information for real patients is limited. In this paper, we have combined non-rigid registration with signal processing techniques to measure pulsation in real patients from high frame rate digital subtraction angiography. We have obtained physiological meaningful waveforms with amplitudes in the range 0 mm-0.3 mm for a population of 18 patients including ruptured and unruptured aneurysms. Statistically significant differences in pulsation were found according to the rupture status, in agreement with differences in biomechanical properties reported in the literature.

  17. Computing myocardial motion in 4-dimensional echocardiography.

    PubMed

    Mukherjee, Ryan; Sprouse, Chad; Pinheiro, Aurélio; Abraham, Theodore; Burlina, Philippe

    2012-07-01

    We describe a novel method for computing dense 3D myocardial motion with high accuracy in four-dimensional (4D) echocardiography (3 dimensions spatial plus time). The method is based on a classic variational optical flow technique but exploits modern developments in optical flow research to utilize the full capabilities of 4D echocardiography. Using a variety of metrics, we present an in-depth performance evaluation of the method on synthetic, phantom, and intraoperative 4D transesophageal echocardiographic data. When compared with state-of-the-art optical flow and speckle tracking techniques currently found in 4D echocardiography, the method we present shows notable improvements in error rates. We believe the performance improvements shown can have a positive impact when the method is used as input for various applications, such as strain computation, biomechanical modeling, and automated diagnostics.

  18. On identification of elementary motion detectors

    NASA Astrophysics Data System (ADS)

    Hidayat, Egi; Medvedev, Alexander; Nordström, Karin

    2013-10-01

    The classical mathematical elementary motion detector (EMD) model stimulated with sinusoidal and pulsatile input signals is treated analytically. Drifting sinusoidal gratings are often used in insect vision research, enabling direct comparison with biological data. When displayed on a cathode ray tube monitor, the sinusoidal grating is modulated by the refresh rate of the monitor. Due to the resulting pulsatile nature of the visual stimuli and the corresponding biological response, a Laguerre domain identification method for estimating the dynamics of a single EMD appears to be suitable. A pool of spatially distributed EMDs is considered as the model for the measured neural output. The weights of the contributing EMDs are evaluated by a sparse optimization method to fit the experimental data.

  19. Motion perception during saccadic eye movements.

    PubMed

    Castet, E; Masson, G S

    2000-02-01

    During rapid eye movements, motion of the stationary world is generally not perceived despite displacement of the whole image on the retina. Here we report that during saccades, human observers sensed visual motion of patterns with low spatial frequency. The effect was greatest when the stimulus was spatiotemporally optimal for motion detection by the magnocellular pathway. Adaptation experiments demonstrated dependence of this intrasaccadic motion percept on activation of direction-selective mechanisms. Even two-dimensional complex motion percepts requiring spatial integration of early motion signals were observed during saccades. These results indicate that the magnocellular pathway functions during saccades, and that only spatiotemporal limitations of visual motion perception are important in suppressing awareness of intrasaccadic motion signals.

  20. Hybrid Motion Planning with Multiple Destinations

    NASA Technical Reports Server (NTRS)

    Clouse, Jeffery

    1998-01-01

    In our initial proposal, we laid plans for developing a hybrid motion planning system that combines the concepts of visibility-based motion planning, artificial potential field based motion planning, evolutionary constrained optimization, and reinforcement learning. Our goal was, and still is, to produce a hybrid motion planning system that outperforms the best traditional motion planning systems on problems with dynamic environments. The proposed hybrid system will be in two parts the first is a global motion planning system and the second is a local motion planning system. The global system will take global information about the environment, such as the placement of the obstacles and goals, and produce feasible paths through those obstacles. We envision a system that combines the evolutionary-based optimization and visibility-based motion planning to achieve this end.

  1. 43 CFR 4.821 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Procedural Rules Applicable to Practice and Procedure for Hearings, Decisions, and Administrative Review... Interior-Effectuation of Title VI of the Civil Rights Act of 1964 Procedures § 4.821 Motions. Motions...

  2. Ideas in Practice - Making Motion More Meaningful

    ERIC Educational Resources Information Center

    Cutchins, Malcolm A.

    1971-01-01

    Three methods of studying motion are described. A wind tunnel is utilized in demonstrating flutter. Computer graphics with an oscilloscope are used to investigate the natural modes of vibration and to track the simulated motion of missiles. (TS)

  3. Motion correction in MRI of the brain

    PubMed Central

    Godenschweger, F; Kägebein, U; Stucht, D; Yarach, U; Sciarra, A; Yakupov, R; Lüsebrink, F; Schulze, P; Speck, O

    2016-01-01

    Subject motion in MRI is a relevant problem in the daily clinical routine as well as in scientific studies. Since the beginning of clinical use of MRI, many research groups have developed methods to suppress or correct motion artefacts. This review focuses on rigid body motion correction of head and brain MRI and its application in diagnosis and research. It explains the sources and types of motion and related artefacts, classifies and describes existing techniques for motion detection, compensation and correction and lists established and experimental approaches. Retrospective motion correction modifies the MR image data during the reconstruction, while prospective motion correction performs an adaptive update of the data acquisition. Differences, benefits and drawbacks of different motion correction methods are discussed. PMID:26864183

  4. Motion correction in MRI of the brain

    NASA Astrophysics Data System (ADS)

    Godenschweger, F.; Kägebein, U.; Stucht, D.; Yarach, U.; Sciarra, A.; Yakupov, R.; Lüsebrink, F.; Schulze, P.; Speck, O.

    2016-03-01

    Subject motion in MRI is a relevant problem in the daily clinical routine as well as in scientific studies. Since the beginning of clinical use of MRI, many research groups have developed methods to suppress or correct motion artefacts. This review focuses on rigid body motion correction of head and brain MRI and its application in diagnosis and research. It explains the sources and types of motion and related artefacts, classifies and describes existing techniques for motion detection, compensation and correction and lists established and experimental approaches. Retrospective motion correction modifies the MR image data during the reconstruction, while prospective motion correction performs an adaptive update of the data acquisition. Differences, benefits and drawbacks of different motion correction methods are discussed.

  5. Anharmonicity in nuclear wobbling motion

    SciTech Connect

    Oi, M.

    2007-09-15

    An unexpected strong anharmonicity was observed in the wobbling spectrum in {sup 163}Lu. In an attempt to understand what causes the deviation from the original wobbling model by Bohr and Mottelson, an analysis is presented using several different approaches, such as exact diagonalization, a semiclassical model to deal with anharmonic wobbling motion, and a microscopic method based on the self-consistent cranking calculation.

  6. p-adic Brownian motion

    NASA Astrophysics Data System (ADS)

    Zelenov, E. I.

    2016-12-01

    We define p-adic Brownian motion (Wiener process) and study its properties. We construct a presentation of the trajectories of this process by their series expansions with respect to van der Put's basis and show that they are nowhere differentiable functions satisfying the p-adic Lipschitz condition of order 1. We define the p-adic Wiener measure on the space of continuous functions and study its properties.

  7. Dynamical Systems and Motion Vision.

    DTIC Science & Technology

    1988-04-01

    TASK Artificial Inteligence Laboratory AREA I WORK UNIT NUMBERS 545 Technology Square . Cambridge, MA 02139 C\\ II. CONTROLLING OFFICE NAME ANO0 ADDRESS...INSTITUTE OF TECHNOLOGY ARTIFICIAL INTELLIGENCE LABORATORY A.I.Memo No. 1037 April, 1988 Dynamical Systems and Motion Vision Joachim Heel Abstract: In this... Artificial Intelligence L3 Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory’s [1 Artificial Intelligence Research is

  8. Guarded Motion for Mobile Robots

    SciTech Connect

    2005-03-30

    The Idaho National Laboratory (INL) has created codes that ensure that a robot will come to a stop at a precise, specified distance from any obstacle regardless of the robot's initial speed, its physical characteristics, and the responsiveness of the low-level motor control schema. This Guarded Motion for Mobile Robots system iteratively adjusts the robot's action in response to information about the robot's environment.

  9. Effects of scopolamine on autonomic profiles underlying motion sickness susceptibility

    NASA Technical Reports Server (NTRS)

    Uijtdehaage, Sebastian H. J.; Stern, Robert M.; Koch, Kenneth L.

    1993-01-01

    The purpose of this study was to examine the effects of scopolamine on the physiological patterns occurring prior to and during motion sickness stimulation. In addition, the use of physiological profiles in the prediction of motion sickness was evaluated. Sixty subjects ingested either 0.6 mg scopolamine, 2.5 mg methoscopolamine, or a placebo. Heart rate (HR), respiratory sinus arrhythmia (an index of vagal tone), and electrogastrograms were measured prior to and during the exposure to a rotating optokinetic drum. Compared to the other groups, the scopolamine group reported fewer motion sickness symptoms, and displayed lower HR, higher vagal tone, enhanced normal gastric myoelectric activity, and depressed gastric dysrhythmias before and during motion sickness induction. Distinct physiological profiles prior to drum rotation could reliably differentiate individuals who would develop gastric discomfort from those who would not. Symptom-free subjects were characterized by high levels of vagal tone and low HR across conditions, and by maintaining normal (3 cpm) electrogastrographic activity during drum rotation. It was concluded that scopolamine offered motion sickness protection by initiating a pattern of increased vagal tone and gastric myoelectric stability.

  10. RHIC stochastic cooling motion control

    SciTech Connect

    Gassner, D.; DeSanto, L.; Olsen, R.H.; Fu, W.; Brennan, J.M.; Liaw, CJ; Bellavia, S.; Brodowski, J.

    2011-03-28

    Relativistic Heavy Ion Collider (RHIC) beams are subject to Intra-Beam Scattering (IBS) that causes an emittance growth in all three-phase space planes. The only way to increase integrated luminosity is to counteract IBS with cooling during RHIC stores. A stochastic cooling system for this purpose has been developed, it includes moveable pick-ups and kickers in the collider that require precise motion control mechanics, drives and controllers. Since these moving parts can limit the beam path aperture, accuracy and reliability is important. Servo, stepper, and DC motors are used to provide actuation solutions for position control. The choice of motion stage, drive motor type, and controls are based on needs defined by the variety of mechanical specifications, the unique performance requirements, and the special needs required for remote operations in an accelerator environment. In this report we will describe the remote motion control related beam line hardware, position transducers, rack electronics, and software developed for the RHIC stochastic cooling pick-ups and kickers.

  11. Shoulder injuries from attacking motion

    NASA Astrophysics Data System (ADS)

    Yanagi, Shigeru; Nishimura, Tetsu; Itoh, Masaru; Wada, Yuhei; Watanabe, Naoki

    1997-03-01

    Sports injuries have bothered professional players. Although many medical doctors try to treat injured players, to prevent sports injuries is more important. Hence, it is required to clear a kinematic mechanism of the sport injuries. A shoulder of volleyball attacker or baseball pitcher is often inured by playing motion. The injuries are mainly caused at the end of long head tendon, which is located in the upper side of scapula. Generally, a muscle and tendon have enough strength against tensile force, however, it seems that they are sometimes defeated by the lateral force. It is imagined that the effect of the lateral force has a possibility of injuring the tendon. If we find the influence of the lateral force on the injured portion, the mechanism of injuries must be cleared. In our research, volleyball attacking motion is taken by high speed video cameras. We analyze the motion as links system and obtain an acceleration of an arm and a shoulder from video image data. The generated force at a shoulder joint is calculated and resolved into the lateral and longitudinal forces. Our final goal is to discuss a possibility that the lateral force causes the injuries.

  12. Validation of the Passenger Ride Quality Apparatus (PRQA) for simulation of aircraft motions for ride-quality research

    NASA Technical Reports Server (NTRS)

    Bigler, W. B., II

    1977-01-01

    The NASA passenger ride quality apparatus (PRQA), a ground based motion simulator, was compared to the total in flight simulator (TIFS). Tests were made on PRQA with varying stimuli: motions only; motions and noise; motions, noise, and visual; and motions and visual. Regression equations for the tests were obtained and subsequent t-testing of the slopes indicated that ground based simulator tests produced comfort change rates similar to actual flight data. It was recommended that PRQA be used in the ride quality program for aircraft and that it be validated for other transportation modes.

  13. Tracking local motion on the beating heart

    NASA Astrophysics Data System (ADS)

    Groeger, Martin; Ortmaier, Tobias; Sepp, Wolfgang; Hirzinger, Gerd

    2002-05-01

    Local motion on the beating heart is investigated in the context of minimally invasive robotic surgery. The focus lies on the motion remaining in the mechanically stabilised field of surgery of the heart. Motion is detected by tracking natural landmarks on the heart surface in 2D video images. An appropriate motion model is presented with a discussion of its degrees of freedom and a trajectory analysis of its parameters.

  14. Optimizing Safe Motion for Autonomous Vehicles

    DTIC Science & Technology

    1994-09-01

    k of the vehicle motion (dk/ds) as the only control variable for the vehicle where s is the length along the vehicle trajectory. Previous motion...function for vehicle motion control is demonstrated by algorithmic simulation and by usc on the autonomous mobile robot Yamabico 11I at the Naval...only control variable for the vehicle, where s is the length along the vehicle trajectory. Previous motion planning of the autonomous mobile robot

  15. Cardiac Motion Analysis Using High-Speed Video Images in a Rat Model for Myocardial Infarction

    NASA Astrophysics Data System (ADS)

    Ishii, Idaku; Okuda, Toshikazu; Nie, Yuman; Takaki, Takeshi; Orito, Kensuke; Tanaka, Akane; Matsuda, Hiroshi

    In this study, we performed a cardiac motion analysis by using 1000-frames per second (fps) stereo images to capture the three-dimensional motion of small color markers in a rat heart. This method of recording cardiac motion could quantify the rate of change in the myocardial area, which indicated localized myocardial activity of rhythmic expansion and contraction. We analyzed the three-dimensional motion distributions in a rat model for myocardial infarction, in which the heart rate was 4 times/s or more. In the analysis, we spatiotemporally quantified the characteristic cardiac motion in ischemic heart diseases and found that infarction due to ischemia in the rat heart was spread around the left ventricle.

  16. Quantitative framework for prospective motion correction evaluation

    PubMed Central

    Pannetier, Nicolas; Stavrinos, Theano; Ng, Peter; Herbst, Michael; Zaitsev, Maxim; Young, Karl; Matson, Gerald; Schuff, Norbert

    2014-01-01

    Purpose Establishing a framework to evaluate performances of prospective motion correction (PMC) MRI considering motion variability between MRI scans. Method A framework was developed to obtain quantitative comparisons between different motion correction setups, considering that varying intrinsic motion patterns between acquisitions can induce bias. Intrinsic motion was considered by replaying in a phantom experiment the recorded motion trajectories from subjects. T1-weighted MRI on five volunteers and two different marker fixations (mouth guard and nose bridge fixations) were used to test the framework. Two metrics were investigated to quantify the improvement of the image quality with PMC. Results Motion patterns vary between subjects as well as between repeated scans within a subject. This variability can be approximated by replaying the motion in a distinct phantom experiment and used as a covariate in models comparing motion corrections. We show that considering the intrinsic motion alters the statistical significance in comparing marker fixations. As an example, two marker fixations, a mouth guard and a nose bridge, were evaluated in terms of their effectiveness for PMC. A mouth guard achieved better PMC performance. Conclusion Intrinsic motion patterns can bias comparisons between PMC configurations and must be considered for robust evaluations. A framework for evaluating intrinsic motion patterns in PMC is presented. PMID:25761550

  17. An Inexpensive Mechanical Model for Projectile Motion

    ERIC Educational Resources Information Center

    Kagan, David

    2011-01-01

    As experienced physicists, we see the beauty and simplicity of projectile motion. It is merely the superposition of uniform linear motion along the direction of the initial velocity vector and the downward motion due to the constant acceleration of gravity. We see the kinematic equations as just the mathematical machinery to perform the…

  18. 49 CFR 511.23 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... § 511.42(e), shall be addressed to the Presiding Officer, who shall rule upon them promptly after affording an opportunity for response. (b) Written motions. All written motions shall state the particular... Secretary and served on all parties, and all motions addressed to the Administrator shall be in writing....

  19. 12 CFR 308.23 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... record unless the administrative law judge directs that such motion be reduced to writing. (c) Filing of... PROCEDURE Uniform Rules of Practice and Procedure § 308.23 Motions. (a) In writing. (1) Except as otherwise provided herein, an application or request for an order or ruling must be made by written motion. (2)...

  20. 17 CFR 12.205 - Motions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Motions. 12.205 Section 12.205... Applicable to Summary Decisional Proceedings § 12.205 Motions. (a) In general. Motions for relief not... may direct. (c) Dismissal—(1) By the Judgment Officer. A Judgment Officer, acting upon his own...

  1. 17 CFR 12.205 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Motions. 12.205 Section 12.205... Applicable to Summary Decisional Proceedings § 12.205 Motions. (a) In general. Motions for relief not... may direct. (c) Dismissal—(1) By the Judgment Officer. A Judgment Officer, acting upon his own...

  2. 17 CFR 12.205 - Motions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Motions. 12.205 Section 12.205... Applicable to Summary Decisional Proceedings § 12.205 Motions. (a) In general. Motions for relief not... may direct. (c) Dismissal—(1) By the Judgment Officer. A Judgment Officer, acting upon his own...

  3. 17 CFR 12.205 - Motions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Motions. 12.205 Section 12.205... Applicable to Summary Decisional Proceedings § 12.205 Motions. (a) In general. Motions for relief not... may direct. (c) Dismissal—(1) By the Judgment Officer. A Judgment Officer, acting upon his own...

  4. 17 CFR 12.205 - Motions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Motions. 12.205 Section 12.205... Applicable to Summary Decisional Proceedings § 12.205 Motions. (a) In general. Motions for relief not... may direct. (c) Dismissal—(1) By the Judgment Officer. A Judgment Officer, acting upon his own...

  5. Rotating rigid motion in general relativity

    SciTech Connect

    Mason, D.P.; Pooe, C.A.

    1987-11-01

    Kinematic and dynamic expressions are derived for the Lie derivative of vorticity along a particle world line in a rigid motion. It is found that the evolution of vorticity in a rigid motion is governed by the electric part of the Weyl tensor. Necessary and sufficient kinematic and dynamic conditions are established for a rotating rigid motion to be isometric.

  6. Motion sickness: a negative reinforcement model.

    PubMed

    Bowins, Brad

    2010-01-15

    Theories pertaining to the "why" of motion sickness are in short supply relative to those detailing the "how." Considering the profoundly disturbing and dysfunctional symptoms of motion sickness, it is difficult to conceive of why this condition is so strongly biologically based in humans and most other mammalian and primate species. It is posited that motion sickness evolved as a potent negative reinforcement system designed to terminate motion involving sensory conflict or postural instability. During our evolution and that of many other species, motion of this type would have impaired evolutionary fitness via injury and/or signaling weakness and vulnerability to predators. The symptoms of motion sickness strongly motivate the individual to terminate the offending motion by early avoidance, cessation of movement, or removal of oneself from the source. The motion sickness negative reinforcement mechanism functions much like pain to strongly motivate evolutionary fitness preserving behavior. Alternative why theories focusing on the elimination of neurotoxins and the discouragement of motion programs yielding vestibular conflict suffer from several problems, foremost that neither can account for the rarity of motion sickness in infants and toddlers. The negative reinforcement model proposed here readily accounts for the absence of motion sickness in infants and toddlers, in that providing strong motivation to terminate aberrant motion does not make sense until a child is old enough to act on this motivation.

  7. 10 CFR 820.39 - Motions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Motions. 820.39 Section 820.39 Energy DEPARTMENT OF ENERGY PROCEDURAL RULES FOR DOE NUCLEAR ACTIVITIES Enforcement Process § 820.39 Motions. (a) General. All motions in an enforcement adjudication except those made orally, shall be in writing, state the grounds...

  8. Sunspots and Their Simple Harmonic Motion

    ERIC Educational Resources Information Center

    Ribeiro, C. I.

    2013-01-01

    In this paper an example of a simple harmonic motion, the apparent motion of sunspots due to the Sun's rotation, is described, which can be used to teach this subject to high-school students. Using real images of the Sun, students can calculate the star's rotation period with the simple harmonic motion mathematical expression.

  9. 10 CFR 2.323 - Motions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Motions. 2.323 Section 2.323 Energy NUCLEAR REGULATORY... raises significant and novel legal or policy issues, or prompt decision by the Commission is necessary to... act. (h) Motions to compel discovery. Parties may file answers to motions to compel discovery...

  10. Ground motion input in seismic evaluation studies

    SciTech Connect

    Sewell, R.T.; Wu, S.C.

    1996-07-01

    This report documents research pertaining to conservatism and variability in seismic risk estimates. Specifically, it examines whether or not artificial motions produce unrealistic evaluation demands, i.e., demands significantly inconsistent with those expected from real earthquake motions. To study these issues, two types of artificial motions are considered: (a) motions with smooth response spectra, and (b) motions with realistic variations in spectral amplitude across vibration frequency. For both types of artificial motion, time histories are generated to match target spectral shapes. For comparison, empirical motions representative of those that might result from strong earthquakes in the Eastern U.S. are also considered. The study findings suggest that artificial motions resulting from typical simulation approaches (aimed at matching a given target spectrum) are generally adequate and appropriate in representing the peak-response demands that may be induced in linear structures and equipment responding to real earthquake motions. Also, given similar input Fourier energies at high-frequencies, levels of input Fourier energy at low frequencies observed for artificial motions are substantially similar to those levels noted in real earthquake motions. In addition, the study reveals specific problems resulting from the application of Western U.S. type motions for seismic evaluation of Eastern U.S. nuclear power plants.

  11. 15 CFR 25.28 - Motions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Motions. 25.28 Section 25.28 Commerce and Foreign Trade Office of the Secretary of Commerce PROGRAM Fraud Civil Remedies § 25.28 Motions. (a... may overrule or deny such motion without awaiting a response. (e) The ALJ shall make a...

  12. 7 CFR 1.327 - Motions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Motions. 1.327 Section 1.327 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Procedures Related to Administrative Hearings Under the Program Fraud Civil Remedies Act of 1986 § 1.327 Motions. (a) Motions shall state the relief sought,...

  13. 41 CFR 105-70.028 - Motions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Motions. 105-70.028 Section 105-70.028 Public Contracts and Property Management Federal Property Management Regulations System...) Except for motions made during a prehearing conference or at the hearing, all motions shall be in...

  14. Human motion perception: Higher-order organization

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Proffitt, Dennis R.

    1990-01-01

    An overview is given of higher-order motion perception and organization. It is argued that motion is sufficient to fully specify a number of environmental properties, including: depth order, three-dimensional form, object displacement, and dynamics. A grammar of motion perception is proposed; applications of this work for display design are discussed.

  15. Fictive Motion in English and Spanish

    ERIC Educational Resources Information Center

    Rojo, Ana; Valenzuela, Javier

    2003-01-01

    This paper analyzes fictive motion expressions in English and Spanish with the twofold aim of (a) finding out whether the differences that have been reported in the expression of motion in English and Spanish also apply to fictive motion, and (b) checking whether the similarities and differences reported by Matsumoto for English and Japanese also…

  16. Teaching Motion with the Global Positioning System

    ERIC Educational Resources Information Center

    Budisa, Marko; Planinsic, Gorazd

    2003-01-01

    We have used the GPS receiver and a PC interface to track different types of motion. Various hands-on experiments that enlighten the physics of motion at the secondary school level are suggested (visualization of 2D and 3D motion, measuring car drag coefficient and fuel consumption). (Contains 8 figures.)

  17. Apollo 16 time and motion study

    NASA Technical Reports Server (NTRS)

    Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.; Saxon, S. C.

    1972-01-01

    A time and motion study is presented of astronaut lunar surface activity on Apollo 16 which consists of five distinct analyses: an evaluation of lunar mobility, a comparison of task performance in 1-g training and lunar EVA, a study of metabolic costs and adaptation, a discussion of falls, and retrieval of fallen objects. Two basic mobility patterns, the hop or canter and the traditional walking gait, were consistently utilized in longer traverses. The metabolic rates associated with these two mobility types, each used by a different astronaut, were relatively equivalent. The time to perform tasks on the lunar surface was significantly longer (on the order of 70%) than the time to perform the same tasks during the last 1-g training session. These results corroborated the findings on Apollo 15 and were not significantly different from them. There was general improvement in lunar EVA performance upon repetition of tasks. Metabolic rate (BTU/hr.) and metabolic cost (BTU) decreased over successive EVAs. Specifically, the metabolic rate associated with riding the lunar roving vehicle (LRV) decreased by approximately 18% from EVA 1 to EVA 2 and by 15% from EVA 2 to EVA 3.

  18. Doppler radar sensing of fish physiological motion

    NASA Astrophysics Data System (ADS)

    Hafner, Noah

    The monitoring vital of signs for fish is critical for advancing the study of trophic and energetic strategies, distributions and behavior, environmental impact, and aquaculture approaches. Presented here is a new approach for monitoring fish metabolic state without the trauma and stress associated with capture, surgical ECG, or other implanted sensing systems. Original research contributions include analysis for radar operation under water, development of radar systems for aquatic operation, and application of these systems to non invasively sense the heart and gill motion of fish. Tilapia and Sturgeon were studied to test the efficacy across varied fish body shapes and sizes, ranging from 0.1 to 1.3m in snout to tail length. Monitoring experiments were conducted with eleven tilapia and three sturgeons to assess activity level participated in these experiments, the results from which include activity level monitoring (tilapia: still or fidgeting 94% of time observed), ventilation rate (tilapia: 42 bpm, sturgeon: 145 bpm), and heart rate (tilapia: 41 bpm, sturgeon: 35 bpm). Bland-Altman analysis of radar and ECG measured heart rate indicate agreement between the two measurement techniques and the suitability of radar as an alternative to ECG. The initial steps for developing a system for practical application is also presented including designs for radar system miniaturization and discussion on further characterization steps with less constrained environments.

  19. Implementation of a markerless motion analysis method to quantify hyperkinesis in males with fragile X syndrome.

    PubMed

    O'Keefe, Joan A; Espinoza Orías, Alejandro A; Khan, Hassan; Hall, Deborah A; Berry-Kravis, Elizabeth; Wimmer, Markus A

    2014-02-01

    Hyperactive behavior - and implicitly, motion - in Fragile X syndrome (FXS) has been historically described using behavioral rating scales. While rating scales are the current standard outcome measures used in clinical research, they have limitations including their qualitative nature and subjectivity. The advent of new motion capture technologies has provided the opportunity to develop quantitative methods for measuring hyperactive motion. The hypotheses for this study were that a novel markerless motion analysis method (1) can quantitatively measure kinematic parameters, (2) can differentiate the level of hyperkinesis between control and FXS populations, and (3) will correlate with blind-reviewer synchronous video-capture methods and behavioral rating scale scores. Twenty young males (7-control, 13-FXS; ages 9-32) were studied using a standardized protocol in a markerless motion analysis suite. Behavioral scale questionnaires were filled out by parents and those scores were correlated with motion parameters (frequency and total traveled distance) of body segments during 30s of story listening while standing in the observation space. The markerless system was able to track subjects and the two populations displayed significantly different quantities of motion, with larger amounts of motion in the FXS group (p < 0.05). Pearson's correlation coefficients between frequency counts obtained from the markerless system and rater-based video capture were between 0.969 and 0.996 (p < 0.001). Significant correlations between rating scale scores and motion parameters ranged from 0.462 ≤ r ≤ 0.568 (p ≤ 0.040). These results suggest feasibility and validity of a markerless system as a non-invasive method able to quantify motion in individuals with hyperkinesis.

  20. Tracking Arabia-India motion from Miocene to Present

    NASA Astrophysics Data System (ADS)

    Chamot-Rooke, N. R.; Fournier, M.

    2009-12-01

    these studies to derive Arabia/India kinematics for the past 20 Myrs. As observed today, opening rates at Sheba ridge and at Carlsberg ridge remained closed since Chron 5D (17.2 Ma), thus pointing to small differential motion between Arabia and India. However, our kinematic model suggests that dextral shearing prevailed since the very beginning of opening of the Gulf of Aden. This has significant implications for the forces that drive the Arabia plate and Arabia-India coupling at their transform boundary. Fournier et al., 2008, In-situ evidence for dextral active motion at the Arabia-India plate boundary, Nature Geoscience, doi:10.1038/ngeo.2007.24. Fournier et al., 2009, Arabia-Somalia plate kinematics, evolution of the Aden-Owen-Carlsberg triple junction, and opening of the Gulf of Aden, J. Geophys. Res., in revision. Merkouriev and DeMets, 2006, Constraints on Indian plate motion since 20 Ma from dense Russian magnetic data: Implications for Indian plate dynamics, Geochem. Geophys. Geosyst., doi:10.1029/2005GC001079.

  1. Tracking 3-D body motion for docking and robot control

    NASA Technical Reports Server (NTRS)

    Donath, M.; Sorensen, B.; Yang, G. B.; Starr, R.

    1987-01-01

    An advanced method of tracking three-dimensional motion of bodies has been developed. This system has the potential to dynamically characterize machine and other structural motion, even in the presence of structural flexibility, thus facilitating closed loop structural motion control. The system's operation is based on the concept that the intersection of three planes defines a point. Three rotating planes of laser light, fixed and moving photovoltaic diode targets, and a pipe-lined architecture of analog and digital electronics are used to locate multiple targets whose number is only limited by available computer memory. Data collection rates are a function of the laser scan rotation speed and are currently selectable up to 480 Hz. The tested performance on a preliminary prototype designed for 0.1 in accuracy (for tracking human motion) at a 480 Hz data rate includes a worst case resolution of 0.8 mm (0.03 inches), a repeatability of plus or minus 0.635 mm (plus or minus 0.025 inches), and an absolute accuracy of plus or minus 2.0 mm (plus or minus 0.08 inches) within an eight cubic meter volume with all results applicable at the 95 percent level of confidence along each coordinate region. The full six degrees of freedom of a body can be computed by attaching three or more target detectors to the body of interest.

  2. Air motion determination by tracking humidity patterns in isentropic layers

    NASA Technical Reports Server (NTRS)

    Mancuso, R. L.; Hall, D. J.

    1975-01-01

    Determining air motions by tracking humidity patterns in isentropic layers was investigated. Upper-air rawinsonde data from the NSSL network and from the AVE-II pilot experiment were used to simulate temperature and humidity profile data that will eventually be available from geosynchronous satellites. Polynomial surfaces that move with time were fitted to the mixing-ratio values of the different isentropic layers. The velocity components of the polynomial surfaces are part of the coefficients that are determined in order to give an optimum fitting of the data. In the mid-troposphere, the derived humidity motions were in good agreement with the winds measured by rawinsondes so long as there were few or no clouds and the lapse rate was relatively stable. In the lower troposphere, the humidity motions were unreliable primarily because of nonadiabatic processes and unstable lapse rates. In the upper troposphere, the humidity amounts were too low to be measured with sufficient accuracy to give reliable results. However, it appears that humidity motions could be used to provide mid-tropospheric wind data over large regions of the globe.

  3. Motion Pattern Encapsulation for Data-Driven Constraint-Based Motion Editing

    NASA Astrophysics Data System (ADS)

    Carvalho, Schubert R.; Boulic, Ronan; Thalmann, Daniel

    The growth of motion capture systems have contributed to the proliferation of human motion database, mainly because human motion is important in many applications, ranging from games entertainment and films to sports and medicine. However, the captured motions normally attend specific needs. As an effort for adapting and reusing captured human motions in new tasks and environments and improving the animator's work, we present and discuss a new data-driven constraint-based animation system for interactive human motion editing. This method offers the compelling advantage that it provides faster deformations and more natural-looking motion results compared to goal-directed constraint-based methods found in the literature.

  4. Recent ground motion studies at Fermilab

    SciTech Connect

    Shiltsev, V.; Volk, J.; Singatulin, S.; /Novosibirsk, IYF

    2009-04-01

    Understanding slow and fast ground motion is important for the successful operation and design for present and future colliders. Since 2000 there have been several studies of ground motion at Fermilab. Several different types of HLS (hydro static level sensors) have been used to study slow ground motion (less than 1 hertz) seismometers have been used for fast (greater than 1 hertz) motions. Data have been taken at the surface and at locations 100 meters below the surface. Data of recent slow ground motion measurements with HLSs, many years of alignment data and results of the ATL-analysis are presented and discussed.

  5. Elements of an improved model of debris-flow motion

    USGS Publications Warehouse

    Iverson, R.M.

    2009-01-01

    A new depth-averaged model of debris-flow motion describes simultaneous evolution of flow velocity and depth, solid and fluid volume fractions, and pore-fluid pressure. Non-hydrostatic pore-fluid pressure is produced by dilatancy, a state-dependent property that links the depth-averaged shear rate and volumetric strain rate of the granular phase. Pore-pressure changes caused by shearing allow the model to exhibit rate-dependent flow resistance, despite the fact that the basal shear traction involves only rate-independent Coulomb friction. An analytical solution of simplified model equations shows that the onset of downslope motion can be accelerated or retarded by pore-pressure change, contingent on whether dilatancy is positive or negative. A different analytical solution shows that such effects will likely be muted if downslope motion continues long enough, because dilatancy then evolves toward zero, and volume fractions and pore pressure concurrently evolve toward steady states. ?? 2009 American Institute of Physics.

  6. Liquid Motion in a Rotating Tank Experiment (LME)

    NASA Technical Reports Server (NTRS)

    Deffenbaugh, D. M.; Dodge, F. T.; Green, S. T.

    1998-01-01

    The Liquid Motion Experiment (LME), which flew on STS 84 in May 1997, was an investigation of liquid motions in spinning, nutating tanks. LME was designed to quantify the effects of such liquid motions on the stability of spinning spacecraft, which are known to be adversely affected by the energy dissipated by the liquid motions. The LME hardware was essentially a spin table which could be forced to nutate at specified frequencies at a constant cone angle, independently of the spin rate. Cylindrical and spherical test tanks, partially filled with liquids of different viscosities, were located at the periphery of the spin table to simulate a spacecraft with off-axis propellant tanks; one set of tanks contained generic propellant management devices (PMDs). The primary quantitative data from the flight tests were the liquid-induced torques exerted on the tanks about radial and tangential axes through the center of the tank. Visual recordings of the liquid oscillations also provided qualitative information. The flight program incorporated two types of tests: sine sweep tests, in which the spin rate was held constant and the nutation frequency varied over a wide range; and sine dwell test, in which both the spin rate and the nutation frequency were held constant. The sine sweep tests were meant to investigate all the prominent liquid resonant oscillations and the damping of the resonances, and the sine dwell tests were meant to quantify the viscous energy dissipation rate of the liquid oscillations for steady state conditions. The LME flight data were compared to analytical results obtained from two companion IR&D programs at Southwest Research Institute. The comparisons indicated that the models predicted the observed liquid resonances, damping, and energy dissipation rates for many test conditions but not for all. It was concluded that improved models and CFD simulations are needed to resolve the differences. This work is ongoing under a current IR&D program.

  7. Inertial motion capture system for biomechanical analysis in pressure suits

    NASA Astrophysics Data System (ADS)

    Di Capua, Massimiliano

    A non-invasive system has been developed at the University of Maryland Space System Laboratory with the goal of providing a new capability for quantifying the motion of the human inside a space suit. Based on an array of six microprocessors and eighteen microelectromechanical (MEMS) inertial measurement units (IMUs), the Body Pose Measurement System (BPMS) allows the monitoring of the kinematics of the suit occupant in an unobtrusive, self-contained, lightweight and compact fashion, without requiring any external equipment such as those necessary with modern optical motion capture systems. BPMS measures and stores the accelerations, angular rates and magnetic fields acting upon each IMU, which are mounted on the head, torso, and each segment of each limb. In order to convert the raw data into a more useful form, such as a set of body segment angles quantifying pose and motion, a series of geometrical models and a non-linear complimentary filter were implemented. The first portion of this works focuses on assessing system performance, which was measured by comparing the BPMS filtered data against rigid body angles measured through an external VICON optical motion capture system. This type of system is the industry standard, and is used here for independent measurement of body pose angles. By comparing the two sets of data, performance metrics such as BPMS system operational conditions, accuracy, and drift were evaluated and correlated against VICON data. After the system and models were verified and their capabilities and limitations assessed, a series of pressure suit evaluations were conducted. Three different pressure suits were used to identify the relationship between usable range of motion and internal suit pressure. In addition to addressing range of motion, a series of exploration tasks were also performed, recorded, and analysed in order to identify different motion patterns and trajectories as suit pressure is increased and overall suit mobility is reduced

  8. A Support System for Motion Training Using Motion Capture and Acceleration Sensors

    NASA Astrophysics Data System (ADS)

    Hayashi, Takahiro; Onai, Rikio

    This paper presents a support system for motion training for dances, sports, gestures, etc. In our previous study, we developed a prototype system for supporting motion training using motion caputure, i.e., marker tracking using a DV camera. The prototype system scores a user's motion by comparing tracking data of the user and a model with DP matching. The prototype system has a limit that it cannot accurately obtain acceleration of each part of the body because marker tracking using a DV camera cannot obtain three dimensional motion. By this limit, two different motions sometimes cannot be distinguished. For more effective motion training, in this study, we propose a system combining motion capture and acceleration sensors. We have examined the effectiveness of using acceleration sensors in motion training by comparing the proposed system with the prototype system. Experimental results have shown that two different motions can be more clearly distinguished by using the acceleration sensors.

  9. Sensing Movement: Microsensors for Body Motion Measurement

    PubMed Central

    Zeng, Hansong; Zhao, Yi

    2011-01-01

    Recognition of body posture and motion is an important physiological function that can keep the body in balance. Man-made motion sensors have also been widely applied for a broad array of biomedical applications including diagnosis of balance disorders and evaluation of energy expenditure. This paper reviews the state-of-the-art sensing components utilized for body motion measurement. The anatomy and working principles of a natural body motion sensor, the human vestibular system, are first described. Various man-made inertial sensors are then elaborated based on their distinctive sensing mechanisms. In particular, both the conventional solid-state motion sensors and the emerging non solid-state motion sensors are depicted. With their lower cost and increased intelligence, man-made motion sensors are expected to play an increasingly important role in biomedical systems for basic research as well as clinical diagnostics. PMID:22346595

  10. Cortical dynamics of visual motion perception: short-range and long-range apparent motion.

    PubMed

    Grossberg, S; Rudd, M E

    1992-01-01

    This article describes further evidence for a new neural network theory of biological motion perception. The theory clarifies why parallel streams V1----V2, V1----MT, and V1----V2----MT exist for static form and motion form processing among the areas V1, V2, and MT of visual cortex. The theory suggests that the static form system (Static BCS) generates emergent boundary segmentations whose outputs are insensitive to direction-of-contrast and to direction-of-motion, whereas the motion form system (Motion BCS) generates emergent boundary segmentations whose outputs are insensitive to direction-of-contrast but sensitive to direction-of-motion. The theory is used to explain classical and recent data about short-range and long-range apparent motion percepts that have not yet been explained by alternative models. These data include beta motion, split motion, gamma motion and reverse-contrast gamma motion, delta motion, and visual inertia. Also included are the transition from group motion to element motion in response to a Ternus display as the interstimulus interval (ISI) decreases; group motion in response to a reverse-contrast Ternus display even at short ISIs; speed-up of motion velocity as interflash distance increases or flash duration decreases; dependence of the transition from element motion to group motion on stimulus duration and size, various classical dependencies between flash duration, spatial separation, ISI, and motion threshold known as Korte's laws; dependence of motion strength on stimulus orientation and spatial frequency; short-range and long-range form-color interactions; and binocular interactions of flashes to different eyes.

  11. Inverse planning incorporating organ motion.

    PubMed

    Li, J G; Xing, L

    2000-07-01

    Accurate targeting is important in intensity-modulated radiation therapy (IMRT). The positional uncertainties of structures with respect to the external beams arise in part from random organ motion and patient setup errors. While it is important to improve immobilization and reduce the influence of organ motion, the residual effects should be included in the IMRT plan design. Current inverse planning algorithms follow the conventional approach and include uncertainties by assuming population-based margins to the target and sensitive structures. Margin around a structure represents a "hard boundary" and the fact that a structure has a spatial probability distribution has been completely ignored. With increasing understanding of spatial uncertainties of structures and the technical capability of fine-tuning the dose distribution on an individual beamlet level in IMRT, it seems timely and important to fully utilize the information in the planning process. This will reduce the "effective" margins of the structures and facilitate dose escalation. Instead of specifying a "hard margin," we describe an inverse planning algorithm which takes into consideration positional uncertainty in terms of spatial probability distribution. The algorithm was demonstrated by assuming that the random organ motion can be represented by a three-dimensional Gaussian distribution function. Other probability distributions can be dealt with similarly. In particular, the commonly used "hard margin" is a special case of the current approach with a uniform probability distribution within a specified range. The algorithm was applied to plan treatment for a prostate case and a pancreatic case. The results were compared with those obtained by adding a margin to the clinical target volume. Better sparing of the sensitive structures were obtained in both cases using the proposed method for approximately the same target coverage.

  12. Brownian motion of helical flagella.

    PubMed

    Hoshikawa, H; Saito, N

    1979-07-01

    We develops a theory of the Brownian motion of a rigid helical object such as bacterial flagella. The statistical properties of the random forces acting on the helical object are discussed and the coefficients of the correlations of the random forces are determined. The averages , and are also calculated where z and theta are the position along and angle around the helix axis respectively. Although the theory is limited to short time interval, direct comparison with experiment is possible by using the recently developed cinematography technique.

  13. Collective organization in aerotactic motion

    NASA Astrophysics Data System (ADS)

    Mazza, Marco G.

    Some bacteria exhibit interesting behavior in the presence of an oxygen concentration. They perform an aerotactic motion along the gradient until they reach their optimal oxygen concentration. But they often organize collectively by forming dense regions, called 'bands', that travel towards the oxygen source. We have developed a model of swimmers with stochastic interaction rules moving in proximity of an air bubble. We perform molecular dynamics simulations and also solve advection-diffusion equations that reproduce the aerotactic behavior of mono-flagellated, facultative anaerobic bacteria. If the oxygen concentration in the system sinks locally below a threshold value, the formation of a migrating aerotactic band toward the bubble can be observed.

  14. Motion gated small animal imaging with a flat-panel CT

    NASA Astrophysics Data System (ADS)

    Grasruck, M.; Bartling, S.; Dinkel, J.; Kiessling, F.; Semmler, W.; Stierstorfer, K.; Schmidt, B.

    2008-03-01

    Small animal CT gains increasing interest in preclinical research. However, physiological motion compensation like in clinical CT has seldom been employed so far. We present different methods of retrospective motion correction for small animal imaging despite their high respiratory and heart rate. Beside respiratory gating alone the combination of respiratory and simultaneous cardiac gating is shown. In vivo data are acquired with an experimental flat-panel based CT scanner*(Siemens Healthcare, Forchheim Germany). Whole mice or rats fit in the available FOV of 25 * 25 * 4 cm 3, while acquisition rate is 100fps. Extrinsic gating is realized by tracing the physiological motion from a small animal monitoring system with a pneumatic pillow for respiratory motion and ECG for heart motion. At the alternative intrinsic method, the lung motion is directly correlated to the movement of the center of gravity in the acquired projection data. As an advantage of the second method the even low preparation effort per scan is reduced. As long as the rotation time of the gantry is far below the cycle time of heart or the lung a multi-segment reconstruction is used in both methods. Motion artifacts are largely suppressed after gating. While in non gated images, the diaphragm, heart contours, bronchi and lung vessels are already visible, they are more sharply defined in the gated datasets. Four-dimensional assessment of lung motion is possible and lung volume in several phases such as peak inspiration and expiration could be segmented, quantified and compared.

  15. Motion sickness severity and physiological correlates during repeated exposures to a rotating optokinetic drum

    NASA Technical Reports Server (NTRS)

    Hu, Senqi; Grant, Wanda F.; Stern, Robert M.; Koch, Kenneth L.

    1991-01-01

    Fifty-two subjects were exposed to a rotating optokinetic drum. Ten of these subjects who became motion sick during the first session completed two additional sessions. Subjects' symptoms of motion sickness, perception of self-motion, electrogastrograms (EGGs), heart rate, mean successive differences of R-R intervals (RRI), and skin conductance were recorded for each session. The results from the first session indicated that the development of motion sickness was accompanied by increased EGG 4-9 cpm activity (gastric tachyarrhythmia), decreased mean succesive differences of RRI, increased skin conductance levels, and increased self-motion perception. The results from the subjects who had three repeated sessions showed that 4-9 cpm EGG activity, skin conductance levels, perception of self-motion, and symptoms of motion sickness all increased significantly during the drum rotation period of the first session, but increased significantly less during the following sessions. Mean successive differences of RRI decreased significantly during the drum rotation period for the first session, but decreased significantly less during the following sessions. Results show that the development of motion sickness is accompanied by an increase in gastric tachyarrhythmia, and an increase in sympathetic activity and a decrease in parasympathetic activity, and that adaptation to motion sickness is accompanied by the recovery of autonomic nervous system balance.

  16. Hotspot motion inferred from mantle flow models: implications on global plate reconstructions

    NASA Astrophysics Data System (ADS)

    Steinberger, B.; O'Connell, R. J.

    2003-04-01

    The Hawaiian hotspot track predicted from a plate circuit, assuming that the Hawaiian hotspot is fixed relative to African hotspots, does not fit the observed track: The divergence is steadily increasing back to 43 Ma, and the predicted track does not show a bend. Here we use a model of plumes distorted by global mantle flow to compute hotspot motion, and test whether this motion can explain the misfit. Computations consistently predict a south- to southeastward motion of the Hawaiian hotspot, and a motion of about 1000 km southward during the past 80 Ma is within the range of model results. Thus, we find that our model of hotspot motion can account for the divergence from 0 to 43 Ma, but can not account for the bend and the track prior to 43 Ma. For this, both a rather sharp change in hotspot motion at 43 Ma, and a westward component of hotspot motion prior to 43 Ma would be required, and neither is predicted in the model. However, a combination of modelled hotspot motion and a relatively modest motion between W and E Antarctica - about 15 degrees clockwise rotation of W vs. E Antarctica - would permit a fit to the Hawaiian track from 80 to 43 My. The required deformation could have been accomplished entirely within continental crust, with rates similar to e.g. present extension in the western U.S., and we will argue that it is not in conflict with, but actually supported by geologic evidence.

  17. Adaptation to real motion reveals direction-selective interactions between real and implied motion processing.

    PubMed

    Lorteije, Jeannette A M; Kenemans, J Leon; Jellema, Tjeerd; van der Lubbe, Rob H J; Lommers, Marjolein W; van Wezel, Richard J A

    2007-08-01

    Viewing static pictures of running humans evokes neural activity in the dorsal motion-sensitive cortex. To establish whether this response arises from direction-selective neurons that are also involved in real motion processing, we measured the visually evoked potential to implied motion following adaptation to static or moving random dot patterns. The implied motion response was defined as the difference between evoked potentials to pictures with and without implied motion. Interaction between real and implied motion was found as a modulation of this difference response by the preceding motion adaptation. The amplitude of the implied motion response was significantly reduced after adaptation to motion in the same direction as the implied motion, compared to motion in the opposite direction. At 280 msec after stimulus onset, the average difference in amplitude reduction between opposite and same adapted direction was 0.5 muV on an average implied motion amplitude of 2.0 muV. These results indicate that the response to implied motion arises from direction-selective motion-sensitive neurons. This is consistent with interactions between real and implied motion processing at a neuronal level.

  18. Zero-Spring-Rate Mechanism/Air Suspension Cart

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Cooley, Victor M.

    1991-01-01

    Compact mechanism suspends articulating flexible structures with minimal constraints. Zero-spring-rate mechanism (ZSRM) air suspension cart used to suspend flexible, "mass-critical" articles like lightweight spacecraft undergoing such large motions as slewing, translation, and telescoping/retraction. Suspends flexible article undergoing large rigid-body motion concurrent with vibratory motion, with minimal interaction between suspended article and suspending hardware. Adaptive to active control, which reduces undesirable effects caused by friction, nonlinearity, and mass coupling. Practical for most suspension applications.

  19. Correlation of Experimental and Theoretical Steady-State Spinning Motion for a Current Fighter Airplane Using Rotation-Balance Aerodynamic Data

    DTIC Science & Technology

    1978-07-01

    required for accurate simulation of spinning motions. Attempts to analytically model departure and spin entry characteristics using measured static...rate of the airplane. Simulated flight motions using measured large angle static aerodynamics did produce more representative motions in the stall...NASA Langley began a program to measure aerodynamic data on airplane models under constant rotating conditions. This program resulted in the

  20. Meshless Modeling of Deformable Shapes and their Motion

    PubMed Central

    Adams, Bart; Ovsjanikov, Maks; Wand, Michael; Seidel, Hans-Peter; Guibas, Leonidas J.

    2010-01-01

    We present a new framework for interactive shape deformation modeling and key frame interpolation based on a meshless finite element formulation. Starting from a coarse nodal sampling of an object’s volume, we formulate rigidity and volume preservation constraints that are enforced to yield realistic shape deformations at interactive frame rates. Additionally, by specifying key frame poses of the deforming shape and optimizing the nodal displacements while targeting smooth interpolated motion, our algorithm extends to a motion planning framework for deformable objects. This allows reconstructing smooth and plausible deformable shape trajectories in the presence of possibly moving obstacles. The presented results illustrate that our framework can handle complex shapes at interactive rates and hence is a valuable tool for animators to realistically and efficiently model and interpolate deforming 3D shapes. PMID:24839614

  1. Extreme ground motions and Yucca Mountain

    USGS Publications Warehouse

    Hanks, Thomas C.; Abrahamson, Norman A.; Baker, Jack W.; Boore, David M.; Board, Mark; Brune, James N.; Cornell, C. Allin; Whitney, John W.

    2013-01-01

    Yucca Mountain is the designated site of the underground repository for the United States' high-level radioactive waste (HLW), consisting of commercial and military spent nuclear fuel, HLW derived from reprocessing of uranium and plutonium, surplus plutonium, and other nuclear-weapons materials. Yucca Mountain straddles the western boundary of the Nevada Test Site, where the United States has tested nuclear devices since the 1950s, and is situated in an arid, remote, and thinly populated region of Nevada, ~100 miles northwest of Las Vegas. Yucca Mountain was originally considered as a potential underground repository of HLW because of its thick units of unsaturated rocks, with the repository horizon being not only ~300 m above the water table but also ~300 m below the Yucca Mountain crest. The fundamental rationale for a geologic (underground) repository for HLW is to securely isolate these materials from the environment and its inhabitants to the greatest extent possible and for very long periods of time. Given the present climate conditions and what is known about the current hydrologic system and conditions around and in the mountain itself, one would anticipate that the rates of infiltration, corrosion, and transport would be very low—except for the possibility that repository integrity might be compromised by low-probability disruptive events, which include earthquakes, strong ground motion, and (or) a repository-piercing volcanic intrusion/eruption. Extreme ground motions (ExGM), as we use the phrase in this report, refer to the extremely large amplitudes of earthquake ground motion that arise at extremely low probabilities of exceedance (hazard). They first came to our attention when the 1998 probabilistic seismic hazard analysis for Yucca Mountain was extended to a hazard level of 10-8/yr (a 10-4/yr probability for a 104-year repository “lifetime”). The primary purpose of this report is to summarize the principal results of the ExGM research program

  2. Biological motion distorts size perception

    NASA Astrophysics Data System (ADS)

    Veto, Peter; Einhäuser, Wolfgang; Troje, Nikolaus F.

    2017-02-01

    Visual illusions explore the limits of sensory processing and provide an ideal testbed to study perception. Size illusions – stimuli whose size is consistently misperceived – do not only result from sensory cues, but can also be induced by cognitive factors, such as social status. Here we investigate, whether the ecological relevance of biological motion can also distort perceived size. We asked observers to judge the size of point-light walkers (PLWs), configurations of dots whose movements induce the perception of human movement, and visually matched control stimuli (inverted PLWs). We find that upright PLWs are consistently judged as larger than inverted PLWs, while static point-light figures do not elicit the same effect. We also show the phenomenon using an indirect paradigm: observers judged the relative size of a disc that followed an inverted PLW larger than a disc following an upright PLW. We interpret this as a contrast effect: The upright PLW is perceived larger and thus the subsequent disc is judged smaller. Together, these results demonstrate that ecologically relevant biological-motion stimuli are perceived larger than visually matched control stimuli. Our findings present a novel case of illusory size perception, where ecological importance leads to a distorted perception of size.

  3. Isentropic Analysis of Convective Motions

    NASA Technical Reports Server (NTRS)

    Pauluis, Olivier M.; Mrowiec, Agnieszka A.

    2013-01-01

    This paper analyzes the convective mass transport by sorting air parcels in terms of their equivalent potential temperature to determine an isentropic streamfunction. By averaging the vertical mass flux at a constant value of the equivalent potential temperature, one can compute an isentropic mass transport that filters out reversible oscillatory motions such as gravity waves. This novel approach emphasizes the fact that the vertical energy and entropy transports by convection are due to the combination of ascending air parcels with high energy and entropy and subsiding air parcels with lower energy and entropy. Such conditional averaging can be extended to other dynamic and thermodynamic variables such as vertical velocity, temperature, or relative humidity to obtain a comprehensive description of convective motions. It is also shown how this approach can be used to determine the mean diabatic tendencies from the three-dimensional dynamic and thermodynamic fields. A two-stream approximation that partitions the isentropic circulation into a mean updraft and a mean downdraft is also introduced. This offers a straightforward way to identify the mean properties of rising and subsiding air parcels. The results from the two-stream approximation are compared with two other definitions of the cloud mass flux. It is argued that the isentropic analysis offers a robust definition of the convective mass transport that is not tainted by the need to arbitrarily distinguish between convection and its environment, and that separates the irreversible convective overturning fromoscillations associated with gravity waves.

  4. SPINNING MOTIONS IN CORONAL CAVITIES

    SciTech Connect

    Wang, Y.-M.; Stenborg, G. E-mail: guillermo.stenborg.ctr.ar@nrl.navy.mi

    2010-08-20

    In movies made from Fe XII 19.5 nm images, coronal cavities that graze or are detached from the solar limb appear as continually spinning structures, with sky-plane projected flow speeds in the range 5-10 km s{sup -1}. These whirling motions often persist in the same sense for up to several days and provide strong evidence that the cavities and the immediately surrounding streamer material have the form of helical flux ropes viewed along their axes. A pronounced bias toward spin in the equatorward direction is observed during 2008. We attribute this bias to the poleward concentration of the photospheric magnetic flux near sunspot minimum, which leads to asymmetric heating along large-scale coronal loops and tends to drive a flow from higher to lower latitudes; this flow is converted into an equatorward spinning motion when the loops pinch off to form a flux rope. As sunspot activity increases and the polar fields weaken, we expect the preferred direction of the spin to reverse.

  5. Polar motion prediction by KASI

    NASA Astrophysics Data System (ADS)

    Na, Sung-Ho; Cho, Jung-Ho; Baek, Jeongho; Kwak, Young-Hee

    2010-05-01

    Korea Astronomy and Space Science Institute(KASI) recently started researches about Earth Rotation. One of KASI's those studies is analysis and prediction of the Earth's pole position - i.e. polar motion. Fitting temporary coefficients of three main components only - Chandler wobble, annual wobble, and 500 day period term has been studied as preliminary one. Both Xp and Yp are modeled as time series composed of constant off set, linear term, and sine and cosine terms for each three periods. The coefficients are determined by using least square error method for each time span of 6.4 years - which is about the beat period of annual wobble and Chandler wobble. Then the prediction of Xp and Yp are made as direct continuation. This approach has been found stable and been applicable to predicting polar motion up to three years. More elaborate models composed of variable coefficients and other minor components are being tested. So far linearly varying amplitude model has been found to be unstable and quite often divergent.

  6. Protrusion Fluctuations Direct Cell Motion

    PubMed Central

    Caballero, David; Voituriez, Raphaël; Riveline, Daniel

    2014-01-01

    Many physiological phenomena involve directional cell migration. It is usually attributed to chemical gradients in vivo. Recently, other cues have been shown to guide cells in vitro, including stiffness/adhesion gradients or micropatterned adhesive motifs. However, the cellular mechanism leading to these biased migrations remains unknown, and, often, even the direction of motion is unpredictable. In this study, we show the key role of fluctuating protrusions on ratchet-like structures in driving NIH3T3 cell migration. We identified the concept of efficient protrusion and an associated direction index. Our analysis of the protrusion statistics facilitated the quantitative prediction of cell trajectories in all investigated conditions. We varied the external cues by changing the adhesive patterns. We also modified the internal cues using drug treatments, which modified the protrusion activity. Stochasticity affects the short- and long-term steps. We developed a theoretical model showing that an asymmetry in the protrusion fluctuations is sufficient for predicting all measures associated with the long-term motion, which can be described as a biased persistent random walk. PMID:24988339

  7. Motion of multiple helical vortices

    NASA Astrophysics Data System (ADS)

    Velasco Fuentes, Oscar

    2015-11-01

    In 1912 Joukowsky deduced that in an unbounded ideal fluid a set of helical vortices--when these are equal, coaxial and symmetrically arranged--would translate and rotate steadily while the vortices preserve their form and relative position. Each vortex is an infinite tube whose cross-section is circular (with radius a) and whose centerline is a helix of pitch L and radius R. The motion is thus determined by three non-dimensional parameters only: the number of vortices N, the vortex radius α = a / R and the vortex pitch τ = L / 2 πR . Here, we express the linear and angular velocities of the vortices as the sum of the mutually induced velocities found by Okulov (2004) and the self-induced velocities found by Velasco Fuentes (2015). We verified that our results are accurate over the whole range of values of the vortices' pitch and radius by numerically computing the vortex motion with two smoothed versions of the Biot-Savart law. It was found that the translation velocity U grows with the number of vortices (N) but decreases as the vortices' radius and pitch (a and τ, respectively) increase; in contrast, the rotation velocity Ω grows with N and a but has a local minimum around τ = 1 for fixed values of N and a.

  8. Biological motion distorts size perception

    PubMed Central

    Veto, Peter; Einhäuser, Wolfgang; Troje, Nikolaus F.

    2017-01-01

    Visual illusions explore the limits of sensory processing and provide an ideal testbed to study perception. Size illusions – stimuli whose size is consistently misperceived – do not only result from sensory cues, but can also be induced by cognitive factors, such as social status. Here we investigate, whether the ecological relevance of biological motion can also distort perceived size. We asked observers to judge the size of point-light walkers (PLWs), configurations of dots whose movements induce the perception of human movement, and visually matched control stimuli (inverted PLWs). We find that upright PLWs are consistently judged as larger than inverted PLWs, while static point-light figures do not elicit the same effect. We also show the phenomenon using an indirect paradigm: observers judged the relative size of a disc that followed an inverted PLW larger than a disc following an upright PLW. We interpret this as a contrast effect: The upright PLW is perceived larger and thus the subsequent disc is judged smaller. Together, these results demonstrate that ecologically relevant biological-motion stimuli are perceived larger than visually matched control stimuli. Our findings present a novel case of illusory size perception, where ecological importance leads to a distorted perception of size. PMID:28205639

  9. Motion as perturbation. II. Development of the method for dosimetric analysis of motion effects with fixed-gantry IMRT

    SciTech Connect

    Nelms, Benjamin E.; Opp, Daniel; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2014-06-15

    s, with the resulting average motion speed of 1.45 cm/s. The motion-perturbed high resolution (2 mm voxel) volumetric dose grids on the MC2 phantom were generated for each beam. From each grid, a coronal dose plane at the detector level was extracted and compared to the corresponding moving MC2 measurement, using gamma analysis with both global (G) and local (L) dose-error normalization. Results: Using the TG-119 criteria of (3%G/3 mm), per beam average gamma analysis passing rates exceeded 95% in all cases. No individual beam had a passing rate below 91%. LDVE correction eliminated systematic disagreement patterns at the beams’ aperture edges. In a representative example, application of LDVE correction improved (2%L/2 mm) gamma analysis passing rate for an IMRT beam from 74% to 98%. Conclusions: The effect of motion on the moving region-of-interest IMRT dose can be estimated with a standard, static phantom QA measurement, provided the motion characteristics are independently known from 4D CT or otherwise. The motion-perturbed absolute dose estimates were validated by the direct planar diode array measurements, and were found to reliably agree with them in a homogeneous phantom.

  10. Rotation Motion of Designed Nano-Turbine

    PubMed Central

    Li, Jingyuan; Wang, Xiaofeng; Zhao, Lina; Gao, Xingfa; Zhao, Yuliang; Zhou, Ruhong

    2014-01-01

    Construction of nano-devices that can generate controllable unidirectional rotation is an important part of nanotechnology. Here, we design a nano-turbine composed of carbon nanotube and graphene nanoblades, which can be driven by fluid flow. Rotation motion of nano-turbine is quantitatively studied by molecular dynamics simulations on this model system. A robust linear relationship is achieved with this nano-turbine between its rotation rate and the fluid flow velocity spanning two orders of magnitude, and this linear relationship remains intact at various temperatures. More interestingly, a striking difference from its macroscopic counterpart is identified: the rotation rate is much smaller (by a factor of ~15) than that of the macroscopic turbine with the same driving flow. This discrepancy is shown to be related to the disruption of water flow at nanoscale, together with the water slippage at graphene surface and the so-called “dragging effect”. Moreover, counterintuitively, the ratio of “effective” driving flow velocity increases as the flow velocity increases, suggesting that the linear dependence on the flow velocity can be more complicated in nature. These findings may serve as a foundation for the further development of rotary nano-devices and should also be helpful for a better understanding of the biological molecular motors. PMID:25068725

  11. Rotation motion of designed nano-turbine.

    PubMed

    Li, Jingyuan; Wang, Xiaofeng; Zhao, Lina; Gao, Xingfa; Zhao, Yuliang; Zhou, Ruhong

    2014-07-28

    Construction of nano-devices that can generate controllable unidirectional rotation is an important part of nanotechnology. Here, we design a nano-turbine composed of carbon nanotube and graphene nanoblades, which can be driven by fluid flow. Rotation motion of nano-turbine is quantitatively studied by molecular dynamics simulations on this model system. A robust linear relationship is achieved with this nano-turbine between its rotation rate and the fluid flow velocity spanning two orders of magnitude, and this linear relationship remains intact at various temperatures. More interestingly, a striking difference from its macroscopic counterpart is identified: the rotation rate is much smaller (by a factor of ~15) than that of the macroscopic turbine with the same driving flow. This discrepancy is shown to be related to the disruption of water flow at nanoscale, together with the water slippage at graphene surface and the so-called "dragging effect". Moreover, counterintuitively, the ratio of "effective" driving flow velocity increases as the flow velocity increases, suggesting that the linear dependence on the flow velocity can be more complicated in nature. These findings may serve as a foundation for the further development of rotary nano-devices and should also be helpful for a better understanding of the biological molecular motors.

  12. Rotation Motion of Designed Nano-Turbine

    NASA Astrophysics Data System (ADS)

    Li, Jingyuan; Wang, Xiaofeng; Zhao, Lina; Gao, Xingfa; Zhao, Yuliang; Zhou, Ruhong

    2014-07-01

    Construction of nano-devices that can generate controllable unidirectional rotation is an important part of nanotechnology. Here, we design a nano-turbine composed of carbon nanotube and graphene nanoblades, which can be driven by fluid flow. Rotation motion of nano-turbine is quantitatively studied by molecular dynamics simulations on this model system. A robust linear relationship is achieved with this nano-turbine between its rotation rate and the fluid flow velocity spanning two orders of magnitude, and this linear relationship remains intact at various temperatures. More interestingly, a striking difference from its macroscopic counterpart is identified: the rotation rate is much smaller (by a factor of ~15) than that of the macroscopic turbine with the same driving flow. This discrepancy is shown to be related to the disruption of water flow at nanoscale, together with the water slippage at graphene surface and the so-called ``dragging effect''. Moreover, counterintuitively, the ratio of ``effective'' driving flow velocity increases as the flow velocity increases, suggesting that the linear dependence on the flow velocity can be more complicated in nature. These findings may serve as a foundation for the further development of rotary nano-devices and should also be helpful for a better understanding of the biological molecular motors.

  13. Depictions of motion devised by a blind person.

    PubMed

    Kennedy, J M; Merkas, C E

    2000-12-01

    A blind man (E.A.) was asked to draw pictures suggesting wheels in various kinds of motion. Six pictures were drawn by E.A. The pictures were shown to sighted subjects, who were asked to assign labels to the pictures, in a multiple-choice format. The labels were assigned at a rate above chance. We argue that the pictures are metaphoric and that pictorial metaphor relies on common properties of the static picture and the kinetic referent.

  14. Real-time head motion detection system

    NASA Astrophysics Data System (ADS)

    Mase, Kenji; Watanabe, Yasuhiko; Suenaga, Yasuhito

    1990-01-01

    We present a three-dimensional head motion detection system called a realtime headreader. This headreader analyzes the head motion picture sequences taken by a TV-camera, and extracts the motion parameters in realtime, i.e. 3-d rotations and translations. We used a simple but very fast algorithm, which exploits the contrast of hair and face to recognize face orientation. The system extracts the head and face area, then estimates the head motion parameters from the change in position of each area's centroids. The head motion is computed at nearly 10 frames per second on a SUN4 workstation and the motion parameters are sent to an IRIS workstation at a 2.5 Kbps. The IRIS generates a head motion sequence that duplicates the original head motion. The entire motion detection program is written in C language. No special image processing hardware is used, except for a video digitizer. Our head motion detection system will enhance man-machine interactions by providing a new visual eue. An operator will be able to point to a target by just looking at it thus a mouse or 3-d tracking device is not needed. The eventual goal of this research is to build an intelligent video communication system that codes the information in terms of high level language rather than compressed video signals.

  15. Motion parallax thresholds for unambiguous depth perception.

    PubMed

    Holmin, Jessica; Nawrot, Mark

    2015-10-01

    The perception of unambiguous depth from motion parallax arises from the neural integration of retinal image motion and extra-retinal eye movement signals. It is only recently that these parameters have been articulated in the form of the motion/pursuit ratio. In the current study, we explored the lower limits of the parameter space in which observers could accurately perform near/far relative depth-sign discriminations for a translating random-dot stimulus. Stationary observers pursued a translating random dot stimulus containing relative image motion. Their task was to indicate the location of the peak in an approximate square-wave stimulus. We measured thresholds for depth from motion parallax, quantified as motion/pursuit ratios, as well as lower motion thresholds and pursuit accuracy. Depth thresholds were relatively stable at pursuit velocities 5-20 deg/s, and increased at lower and higher velocities. The pattern of results indicates that minimum motion/pursuit ratios are limited by motion and pursuit signals, both independently and in combination with each other. At low and high pursuit velocities, depth thresholds were limited by inaccurate pursuit signals. At moderate pursuit velocities, depth thresholds were limited by motion signals.

  16. SinoCor: motion correction in SPECT

    NASA Astrophysics Data System (ADS)

    Mitra, Debasis; Eiland, Daniel; Abdallah, Mahmoud; Bouthcko, Rostyslav; Gullberg, Grant T.; Schechtmann, Norberto

    2012-02-01

    Motion is a serious artifact in Cardiac nuclear imaging because the scanning operation takes a long time. Since reconstruction algorithms assume consistent or stationary data the quality of resulting image is affected by motion, sometimes significantly. Even after adoption of the gold standard MoCo(R) algorithm from Cedars-Sinai by most vendors, heart motion remains a significant challenge. Also, any serious study in quantitative analysis necessitates correction for motion artifacts. It is generally recognized that human eye is a very sensitive tool for detecting motion. However, two reasons prevent such manual correction: (1) it is costly in terms of specialist's time, and (2) no such tool for manual correction is available currently. Previously, at SPIE-MIC'11, we presented a simple tool (SinoCor) that allows sinograms to be corrected manually or automatically. SinoCor performs correction of sinograms containing inter-frame patient or respiratory motions using rigid-body dynamics. The software is capable of detecting the patient motion and estimating the body-motion vector using scanning geometry parameters. SinoCor applies appropriate geometrical correction to all the frames subsequent to the frame when the movement has occurred in a manual or automated mode. For respiratory motion, it is capable of automatically smoothing small oscillatory (frame-wise local) movements. Lower order image moments are used to represent a frame and the required rigid body movement compensation is computed accordingly. Our current focus is on enhancement of SinoCor with the capability to automatically detect and compensate for intra-frame motion that causes motion blur on the respective frame. Intra-frame movements are expected in both patient and respiratory motions. For a controlled study we also have developed a motion simulator. A stable version of SinoCor is available under license from Lawrence Berkeley National Laboratory.

  17. MotionFlow: Visual Abstraction and Aggregation of Sequential Patterns in Human Motion Tracking Data.

    PubMed

    Jang, Sujin; Elmqvist, Niklas; Ramani, Karthik

    2016-01-01

    Pattern analysis of human motions, which is useful in many research areas, requires understanding and comparison of different styles of motion patterns. However, working with human motion tracking data to support such analysis poses great challenges. In this paper, we propose MotionFlow, a visual analytics system that provides an effective overview of various motion patterns based on an interactive flow visualization. This visualization formulates a motion sequence as transitions between static poses, and aggregates these sequences into a tree diagram to construct a set of motion patterns. The system also allows the users to directly reflect the context of data and their perception of pose similarities in generating representative pose states. We provide local and global controls over the partition-based clustering process. To support the users in organizing unstructured motion data into pattern groups, we designed a set of interactions that enables searching for similar motion sequences from the data, detailed exploration of data subsets, and creating and modifying the group of motion patterns. To evaluate the usability of MotionFlow, we conducted a user study with six researchers with expertise in gesture-based interaction design. They used MotionFlow to explore and organize unstructured motion tracking data. Results show that the researchers were able to easily learn how to use MotionFlow, and the system effectively supported their pattern analysis activities, including leveraging their perception and domain knowledge.

  18. An Alternative Estimate of the Motion of the Capricorn Plate

    NASA Astrophysics Data System (ADS)

    Burris, S. G.; Gordon, R. G.

    2013-12-01

    Diffuse plate boundaries cover ~15% of Earth's surface and can exceed 1000 km in across-strike width. Deforming oceanic lithosphere in the equatorial Indian Ocean accommodates the motion between the India and Capricorn plates and serves as their mutual diffuse plate boundary. This deforming lithosphere lies between the Central Indian Ridge to the west and the Sumatra trench to the east; the plates diverge to the west of ≈74°E and converge to the east of it. Many data have shown that the pole of rotation between the India and Capricorn plates lies within this diffuse plate boundary [1,2]. Surprisingly, however, the recently estimated angular velocity in the MORVEL global set of angular velocities [3] places this pole of rotation north of prior poles by several degrees, and north of the diffuse plate boundary. The motion between the India and Capricorn plates can only be estimated indirectly by differencing the motion of the India plate relative to the Somalia plate, on the one hand, and the motion of the Capricorn plate relative to Somalia plate, on the other. While the MORVEL India-Somalia angular velocity is similar to prior estimates, the MORVEL Capricorn-Somalia pole of rotation lies northwest of its predecessors. The difference is not caused by new transform azimuth data incorporated into MORVEL or by the new application of a correction to spreading rates for outward displacement. Instead the difference appears to be caused by a few anomalous spreading rates near the northern end of the Capricorn-Somalia plate boundary along the Central Indian Ridge. Rejecting these data leads to consistency with prior results. Implications for the motion of the Capricorn plate relative to Australia will be discussed. [1] DeMets, C., R. G. Gordon, and J.-Y. Royer, 2005. Motion between the Indian, Capricorn, and Somalian plates since 20 Ma: implications for the timing and magnitude of distributed deformation in the equatorial Indian ocean, Geophys. J. Int., 161, 445-468. [2

  19. List mode reconstruction for PET with motion compensation: A simulation study

    SciTech Connect

    Qi, Jinyi; Huesman, Ronald H.

    2002-07-01

    Motion artifacts can be a significant factor that limits the image quality in high-resolution PET. Surveillance systems have been developed to track the movements of the subject during a scan. Development of reconstruction algorithms that are able to compensate for the subject motion will increase the potential of PET. In this paper we present a list mode likelihood reconstruction algorithm with the ability of motion compensation. The subject motion is explicitly modeled in the likelihood function. The detections of each detector pair are modeled as a Poisson process with time-varying rate function. The proposed method has several advantages over the existing methods. It uses all detected events and does not introduce any interpolation error. Computer simulations show that the proposed method can compensate simulated subject movements and that the reconstructed images have no visible motion artifacts.

  20. “What Women Like”: Influence of Motion and Form on Esthetic Body Perception

    PubMed Central

    Cazzato, Valentina; Siega, Serena; Urgesi, Cosimo

    2012-01-01

    Several studies have shown the distinct contribution of motion and form to the esthetic evaluation of female bodies. Here, we investigated how variations of implied motion and body size interact in the esthetic evaluation of female and male bodies in a sample of young healthy women. Participants provided attractiveness, beauty, and liking ratings for the shape and posture of virtual renderings of human bodies with variable body size and implied motion. The esthetic judgments for both shape and posture of human models were influenced by body size and implied motion, with a preference for thinner and more dynamic stimuli. Implied motion, however, attenuated the impact of extreme body size on the esthetic evaluation of body postures, while body size variations did not affect the preference for more dynamic stimuli. Results show that body form and action cues interact in esthetic perception, but the final esthetic appreciation of human bodies is predicted by a mixture of perceptual and affective evaluative components. PMID:22866044

  1. Developments in Human Centered Cueing Algorithms for Control of Flight Simulator Motion Systems

    NASA Technical Reports Server (NTRS)

    Houck, Jacob A.; Telban, Robert J.; Cardullo, Frank M.

    1997-01-01

    The authors conducted further research with cueing algorithms for control of flight simulator motion systems. A variation of the so-called optimal algorithm was formulated using simulated aircraft angular velocity input as a basis. Models of the human vestibular sensation system, i.e. the semicircular canals and otoliths, are incorporated within the algorithm. Comparisons of angular velocity cueing responses showed a significant improvement over a formulation using angular acceleration input. Results also compared favorably with the coordinated adaptive washout algorithm, yielding similar results for angular velocity cues while eliminating false cues and reducing the tilt rate for longitudinal cues. These results were confirmed in piloted tests on the current motion system at NASA-Langley, the Visual Motion Simulator (VMS). Proposed future developments by the authors in cueing algorithms are revealed. The new motion system, the Cockpit Motion Facility (CMF), where the final evaluation of the cueing algorithms will be conducted, is also described.

  2. The effect of motion on IMRT - looking at interplay with 3D measurements

    NASA Astrophysics Data System (ADS)

    Thomas, A.; Yan, H.; Oldham, M.; Juang, T.; Adamovics, J.; Yin, F. F.

    2013-06-01

    Clinical recommendations to address tumor motion management have been derived from studies dealing with simulations and 2D measurements. 3D measurements may provide more insight and possibly alter the current motion management guidelines. This study provides an initial look at true 3D measurements involving leaf motion deliveries by use of a motion phantom and the PRESAGE/DLOS dosimetry system. An IMRT and VMAT plan were delivered to the phantom and analyzed by means of DVHs to determine whether the expansion of treatment volumes based on known imaging motion adequately cover the target. DVHs confirmed that for these deliveries the expansion volumes were adequate to treat the intended target although further studies should be conducted to allow for differences in parameters that could alter the results, such as delivery dose and breathe rate.

  3. A triboelectric motion sensor in wearable body sensor network for human activity recognition.

    PubMed

    Hui Huang; Xian Li; Ye Sun

    2016-08-01

    The goal of this study is to design a novel triboelectric motion sensor in wearable body sensor network for human activity recognition. Physical activity recognition is widely used in well-being management, medical diagnosis and rehabilitation. Other than traditional accelerometers, we design a novel wearable sensor system based on triboelectrification. The triboelectric motion sensor can be easily attached to human body and collect motion signals caused by physical activities. The experiments are conducted to collect five common activity data: sitting and standing, walking, climbing upstairs, downstairs, and running. The k-Nearest Neighbor (kNN) clustering algorithm is adopted to recognize these activities and validate the feasibility of this new approach. The results show that our system can perform physical activity recognition with a successful rate over 80% for walking, sitting and standing. The triboelectric structure can also be used as an energy harvester for motion harvesting due to its high output voltage in random low-frequency motion.

  4. Endocrine correlates of susceptibility to motion sickness

    NASA Technical Reports Server (NTRS)

    Kohl, R. L.

    1985-01-01

    Motion sickness releases ACTH, epinerphrine, and norepinephrine. The endocrine responses to motion sickness, adaptive responses leading to the resolution of the syndrome, and the way in which antimotion-sickness drugs influence the endocrine responses were studied. Susceptible or insusceptible subjects were administered antimotion-sickness drugs prior to stressful stimulation. Insusceptible subjects displayed more pronounced elevations of ACTH, epinephrine, and norepinephrine after stressful motion. Predrug levels of ACTH were higher in insusceptible subjects (p less than 0.01). Acute blockade of hormone responses to stressful motion or alteration of levels of ACTH by drugs were not correlated with individual susceptibility. No correlation was apparent between epinephrine and ACTH release. These endocrine differences may represent neurochemical markers for susceptibility to motion, stress, or general adaptability, and it may be that the chronic modulation of their levels might be more effective in preventing motion sickness than the acute blockage or stimulation of specific receptors.

  5. Contrast-Independent Biologically Inspired Motion Detection

    PubMed Central

    Babies, Birthe; Lindemann, Jens Peter; Egelhaaf, Martin; Möller, Ralf

    2011-01-01

    Optic flow, i.e., retinal image movement resulting from ego-motion, is a crucial source of information used for obstacle avoidance and course control in flying insects. Optic flow analysis may prove promising for mobile robotics although it is currently not among the standard techniques. Insects have developed a computationally cheap analysis mechanism for image motion. Detailed computational models, the so-called elementary motion detectors (EMDs), describe motion detection in insects. However, the technical application of EMDs is complicated by the strong effect of local pattern contrast on their motion response. Here we present augmented versions of an EMD, the (s)cc-EMDs, which normalise their responses for contrast and thereby reduce the sensitivity to contrast changes. Thus, velocity changes of moving natural images are reflected more reliably in the detector response. The (s)cc-EMDs can easily be implemented in hardware and software and can be a valuable novel visual motion sensor for mobile robots. PMID:22163800

  6. Motion sickness: Can it be controlled

    NASA Technical Reports Server (NTRS)

    Carnes, David

    1988-01-01

    NASA is one of the few research centers concerned with motion sickness. Since the physiology of man has been developed in the one-gravity field Earth, the changes experienced by man in space are unique, and often result in symptoms that resemble motion sickness on Earth. NASA is concerned with motion sickness because it is very uncomfortable for the astronauts. Another concern of NASA is the possibility of a motion sickness astronaut regurgitating while he or she is sealed in an airtight space suit. This could be fatal. Motivated by these reasons, NASA spent thousands of dollars in research and development for a drug or technique for combating motion sickness. Several different treatments were developed for this disorder. Three of the most effective ways of combatting motion sickness are discussed.

  7. Movie Ratings and Revenues: Eleven Years of Success Ratios.

    ERIC Educational Resources Information Center

    Austin, Bruce A.; And Others

    The relation between revenues from motion pictures and the picture ratings (G, PG, R, X) by the Motion Picture Association of America was examined. Successful films were those listed by "Variety" magazine as the top revenue producers for the given year. Data were collected for the years 1969-1979. The analysis showed that years in which…

  8. What Is Being Done to Control Motion Sickness?

    NASA Technical Reports Server (NTRS)

    Hall, Y. D.

    1985-01-01

    AFT (Autogenic Feedback Training) involves practicing a series of mental exercises to speed up or slow down the control of autonomic activity. This produces a reduced tendency for autonomic activity levels to diverge from baseline (at rest) under stressful motion-sickness-inducing conditions. Subjects conditions. Subjects engaged in applying AFT exercises are required to closely monitor their own bodily sensations during motion-sickness-eliciting tests. These tests include the Coriolis Sickness Susceptibility Index (CSSI), which consists of sitting a subject into a rotating chair that moves at various speeds while a visual background turns at differing speeds and directions, and the Vertical Acceleration Rotation Device (VARD) test, which involves the placing of a subject in a drum that moves in an upward and downward motion until he or she is sick, while simultaneously monitoring the subject's vital signs. These tests provide investigators with evidence of slight changes in autonomic activities such as increases in heart rate, skin temperature, and sweat. All of these symptoms occur in subjects that experience bodily weakness or discomfort with the onset of motion sickness.

  9. Fast motion prediction algorithm for multiview video coding

    NASA Astrophysics Data System (ADS)

    Abdelazim, Abdelrahman; Zhang, Guang Y.; Mein, Stephen J.; Varley, Martin R.; Ait-Boudaoud, Djamel

    2011-06-01

    Multiview Video Coding (MVC) is an extension to the H.264/MPEG-4 AVC video compression standard developed with joint efforts by MPEG/VCEG to enable efficient encoding of sequences captured simultaneously from multiple cameras using a single video stream. Therefore the design is aimed at exploiting inter-view dependencies in addition to reducing temporal redundancies. However, this further increases the overall encoding complexity In this paper, the high correlation between a macroblock and its enclosed partitions is utilised to estimate motion homogeneity, and based on the result inter-view prediction is selectively enabled or disabled. Moreover, if the MVC is divided into three layers in terms of motion prediction; the first being the full and sub-pixel motion search, the second being the mode selection process and the third being repetition of the first and second for inter-view prediction, the proposed algorithm significantly reduces the complexity in the three layers. To assess the proposed algorithm, a comprehensive set of experiments were conducted. The results show that the proposed algorithm significantly reduces the motion estimation time whilst maintaining similar Rate Distortion performance, when compared to both the H.264/MVC reference software and recently reported work.

  10. An Adaptive Motion Estimation Scheme for Video Coding

    PubMed Central

    Gao, Yuan; Jia, Kebin

    2014-01-01

    The unsymmetrical-cross multihexagon-grid search (UMHexagonS) is one of the best fast Motion Estimation (ME) algorithms in video encoding software. It achieves an excellent coding performance by using hybrid block matching search pattern and multiple initial search point predictors at the cost of the computational complexity of ME increased. Reducing time consuming of ME is one of the key factors to improve video coding efficiency. In this paper, we propose an adaptive motion estimation scheme to further reduce the calculation redundancy of UMHexagonS. Firstly, new motion estimation search patterns have been designed according to the statistical results of motion vector (MV) distribution information. Then, design a MV distribution prediction method, including prediction of the size of MV and the direction of MV. At last, according to the MV distribution prediction results, achieve self-adaptive subregional searching by the new estimation search patterns. Experimental results show that more than 50% of total search points are dramatically reduced compared to the UMHexagonS algorithm in JM 18.4 of H.264/AVC. As a result, the proposed algorithm scheme can save the ME time up to 20.86% while the rate-distortion performance is not compromised. PMID:24672313

  11. Yukawa effects on the mean motion of an orbiting body

    NASA Astrophysics Data System (ADS)

    Haranas, Ioannis; Kotsireas, Ilias; Gómez, Guillem; Fullana, Màrius J.; Gkigkitzis, Ioannis

    2016-11-01

    In today's gravity research there exist few modified gravitational theories which among other things predict the existence of a Yukawa-type correction to the classical gravitational potential. In this paper we study the Yukawa effect on the mean motion if any in a two-body scenario, assuming the influence of the existence of a possible Yukawa correction in the gravitational force of a primary. For that, we derive an equation in order to approximate the mean motion for secondary time rate of change of the orbiting body and its total variation over one revolution, under the influence of the non-Newtonian radial acceleration. Numerical results for Mercury and the companion star of the pulsar PSR 1913+16 are calculated. For specific values of the parameters α and λ, as given in the bibliography we have found that there is no corresponding Yukawa effect affecting the mean motion of the planet Mercury. On the other hand it appears that there is a periodic Yukawa effect that affects the mean motion of PSR+16 whose maximum numerical value occurs when the eccentric anomaly is equal to 180°.

  12. Video compression using conditional replenishment and motion prediction

    NASA Technical Reports Server (NTRS)

    Hein, D. N.; Ahmed, N.

    1984-01-01

    A study of a low-rate monochrome video compression system is presentd in this paper. This system is a conditional-replenishment coder that uses two-dimensional Walsh-transform coding within each video frame. The conditional-replenishment algorithm works by transmitting only the portions of an image that are changing in time. This system is augmented with a motn-prediction algorithm that measures spatial dispalcement parameters from frame to frame, and codes the data using these parameters. A comparison is made between the conditional-replenishment system with, and without, the motion-predictinalgorthm. Subsampling in time is ued to maintain the data rate rate at a fixed value. Average bit rates of 1 bit/picture element (pel) to 1/16 bit/pel are considered. The resultant performance of the compression simulations is presented in terms of the average frame rates produced.

  13. Sparseness and Roughness of Foreign Exchange Rates

    NASA Astrophysics Data System (ADS)

    Vandewalle, N.; Ausloos, M.

    An accurate multiaffine analysis of 23 foreign currency exchange rates has been performed. The roughness exponent H1 which characterizes the excursion of the exchange rate has been numerically measured. The degree of intermittency C1 has been also estimated. In the (H1,C1) phase diagram, the currency exchange rates are dispersed in a wide region around the Brownian motion value (H1=0.5,C1=0) and have a significantly intermittent component (C1≠0).

  14. Motion compensation for ultra wide band SAR

    NASA Technical Reports Server (NTRS)

    Madsen, S.

    2001-01-01

    This paper describes an algorithm that combines wavenumber domain processing with a procedure that enables motion compensation to be applied as a function of target range and azimuth angle. First, data are processed with nominal motion compensation applied, partially focusing the image, then the motion compensation of individual subpatches is refined. The results show that the proposed algorithm is effective in compensating for deviations from a straight flight path, from both a performance and a computational efficiency point of view.

  15. General techniques for constrained motion planning

    SciTech Connect

    Hwang, Yong K.; Watterberg, P.A.; Chen, Pang, C.; Lewis, C.L.

    1997-02-01

    This report presents automatic motion planning algorithms for robotic manipulators performing a variety of tasks. Given a task and a robot manipulator equipped with a tool in its hand, the motion planners compute robot motions to complete the task while respecting manipulator kinematic constraints and avoiding collisions with objects in the robot`s work space. To handle the high complexity of the motion planning problem, a sophisticated search strategy called SANDROS is developed and used to solve many variations of the motion planning problem. To facilitate systematic development of motion planning algorithms, robotic tasks are classified into three categories according to the dimension of the manifold the robot tool has to travel: visit-point (0 dimensional), trace-curve (1 dimensional) and cover-surface (2 dimensional) tasks. The motion planner for a particular dimension is used as a sub-module by the motion planner for the next-higher dimension. This hierarchy of motion planners has led to a set of compact and systematic algorithms that can plan robot motions for many types of robotic operations. In addition, an algorithm is developed that determines the optimal robot-base configuration for minimum cycle time. The SANDROS search paradigm is complete in that it finds a solution path if one exists, up to a user specified resolution. Although its worst-case time complexity is exponential in the degrees of freedom of the manipulator, its average performance is commensurate with the complexity of the solution path. Since solution paths for most of motion planning problems consist of a few monotone segments, the motion planners based on SANDROS search strategy show approximately two-orders of magnitude improvements over existing complete algorithms.

  16. Visual Motion Perception and Visual Information Processing

    DTIC Science & Technology

    1993-12-31

    accepted. van Santen & Sperling (1985) showed the equivalence of two subsequent models (Adelson & Bergen, Watson & Ahumada ) to the van Santen-Sperling...Adelson & Bergen, 1985 and Watson & Ahumada , 1985) for which no experimental data had yet been generated, were computationally equivalent to the elaborated...standard motion analysis directly to luminance (e.g., Adelson-Bergen motion-energy analyzers, Watson- Ahumada motion sensors, or elaborated Reichardt

  17. Visual Motion Perception and Visual Information Processing

    DTIC Science & Technology

    1991-02-01

    Weichselgartner in the HIPL. These are empirical studies of attention plus extensive Monte Carlo simulations of a comprehensive model. Additionally, Ms. Shi is...motion-energy analyzer, a Watson Ahumada motion sensor, or by any elaborated Reichardt detector). and b)cannot be exposed to standard motion analysis by...Bergen. 1985). a Watson Ahumada Reprint requests should he sent to Charles Chubb. Department of Psychology. Rutgers University. New Brunswick. N.1

  18. Dynamic signatures of driven vortex motion.

    SciTech Connect

    Crabtree, G. W.; Kwok, W. K.; Lopez, D.; Olsson, R. J.; Paulius, L. M.; Petrean, A. M.; Safar, H.

    1999-09-16

    We probe the dynamic nature of driven vortex motion in superconductors with a new type of transport experiment. An inhomogeneous Lorentz driving force is applied to the sample, inducing vortex velocity gradients that distinguish the hydrodynamic motion of the vortex liquid from the elastic and-plastic motion of the vortex solid. We observe elastic depinning of the vortex lattice at the critical current, and shear induced plastic slip of the lattice at high Lorentz force gradients.

  19. Unity of measurement and motion.

    PubMed

    Conrad, M

    2001-01-01

    Issues addressed in H.H. Pattee's origin of life laboratory in the 1960s and their connection to the physics-evolution-language problematic are indicated. The problem of quantum measurement played a central role. The problem is herein examined in the light of the fluctuon model; in particular, as the model applies to gravity. The main conclusion is that measurement and motion are a unitary process. All accelerations are accompanied by a cycle involving the annihilation and creation of superpositions. Gravitational collapse is also a cyclic process in the fluctuon model. By a suitable transformation, it can be seen that interactions underlying superpositional collapse are the same as those operative in gravitational collapse. Implications for the origin of cellular life and the development of symbolic systems are considered.

  20. Localised Plate Motion on Venus

    NASA Astrophysics Data System (ADS)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.