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Sample records for absolute claudication distance

  1. Absolute travel distance from optic flow.

    PubMed

    Frenz, Harald; Lappe, Markus

    2005-06-01

    Optic flow fields provide rich information about the observer's self-motion. Besides estimation of the direction of self-motion human observers are also able to discriminate the travel distances of two self-motion simulations. Recent studies have shown that observers estimate the simulated ego velocity of the self-motion simulation and integrate it over time. Thus, observers use a 3-D percept of the ego motion through the environment. In the present work we ask if human observers are able to use this 3-D percept of the motion simulation to build up an internal representation of travel distance and indicate it in a static scene. We visually simulated self-motion in different virtual environments and asked subjects to indicate the perceived distances in terms of static virtual intervals on the ground. The results show that human observers possess a static distance gauge, but that they undershoot the travel distances for short motion simulations. In further experiments we changed the modality of the distance indication but the undershoot in distance estimation remained. This suggests that the undershoot is linked to the perception of the optic flow field.

  2. Low cost varying synthetic wavelength technique for absolute distance measurement

    NASA Astrophysics Data System (ADS)

    Le Floch, S.; Salvadé, Y.

    2010-04-01

    A new low-cost superheterodyne configuration, without acousto-optic modulator, is applied to the two-wavelength interferometry for absolute distance measurement. The principle relies on a synchronized frequency sweep of two optical signals, but with different frequency excursions. The frequency difference between the two optical waves is highly accurate. This is realized by injecting a frequency modulated laser signal in an intensity modulator that is biased at halfwave voltage and driven by a digitally swept radio-frequency signal between 13 and 15 GHz. This latter is a continuous up and down ramp. The two synchronized optical signals emerging from the modulator produce in a Michelson interferometer a distance dependent superheterodyne signal, with a variable synthetic wavelength of about 10 mm. The superheterodyne frequency depends linearly on distance and on the radio-frequency excursion. The integration time for a distance measurement point corresponds to the duration of single sweep (i.e. one millisecond in our case). Absolute distance measurements from 1 to 15 meters yield an accuracy of +/-50 μm, showing the validity of the technique.

  3. Global-Scale Location and Distance Estimates: Common Representations and Strategies in Absolute and Relative Judgments

    ERIC Educational Resources Information Center

    Friedman, Alinda; Montello, Daniel R.

    2006-01-01

    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although…

  4. Dynamic frequency-domain interferometer for absolute distance measurements with high resolution

    SciTech Connect

    Weng, Jidong; Liu, Shenggang; Ma, Heli; Tao, Tianjiong; Wang, Xiang; Liu, Cangli; Tan, Hua

    2014-11-15

    A unique dynamic frequency-domain interferometer for absolute distance measurement has been developed recently. This paper presents the working principle of the new interferometric system, which uses a photonic crystal fiber to transmit the wide-spectrum light beams and a high-speed streak camera or frame camera to record the interference stripes. Preliminary measurements of harmonic vibrations of a speaker, driven by a radio, and the changes in the tip clearance of a rotating gear wheel show that this new type of interferometer has the ability to perform absolute distance measurements both with high time- and distance-resolution.

  5. The correction of vibration in frequency scanning interferometry based absolute distance measurement system for dynamic measurements

    NASA Astrophysics Data System (ADS)

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-10-01

    Absolute distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an absolute distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based absolute distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.

  6. Radio frequency controlled synthetic wavelength sweep for absolute distance measurement by optical interferometry

    SciTech Connect

    Le Floch, Sebastien; Salvade, Yves; Mitouassiwou, Rostand; Favre, Patrick

    2008-06-01

    We present a new technique applied to the variable optical synthetic wavelength generation in optical interferometry. It consists of a chain of optical injection locking among three lasers: first a distributed-feedback laser is used as a master to injection lock an intensity-modulated laser that is directly modulated around 15 GHz by a radio frequency generator on a sideband. A second distributed-feedback laser is injection locked on another sideband of the intensity-modulated laser. The variable synthetic wavelength for absolute distance measurement is simply generated by sweeping the radio frequency over a range of several hundred megahertz, which corresponds to the locking range of the two slave lasers. In this condition, the uncertainty of the variable synthetic wavelength is equivalent to the radio frequency uncertainty. This latter has a relative accuracy of 10{sup -7} or better, resulting in a resolution of {+-}25 {mu}m for distances exceeding tens of meters. The radio frequency generator produces a linear frequency sweep of 1 ms duration (i.e., exactly equal to one absolute distance measurement acquisition time), with frequency steps of about 1 MHz. Finally, results of absolute distance measurements for ranges up to 10 m are presented.

  7. High precision absolute distance measurement with the fiber femtosecond optical frequency comb

    NASA Astrophysics Data System (ADS)

    Guo, Jiashuai; Wu, Tengfei; Liang, Zhiguo; Wang, Yu; Han, Jibo

    2016-01-01

    The absolute distance measurement was experimentally demonstrated by using the fiber femtosecond optical frequency comb in air. The technique is based on the measurement of cross correlation between reference and measurement optical pulses. This method can achieve accuracy better than the commercial laser interferometer. It is attained sub-micrometer resolution in large scale measurement by using the fiber femtosecond optical frequency comb. It will be benefit for future laser lidar and satellite formation flying mission.

  8. Dispersive white-light interferometry for absolute distance measurement with dielectric multilayer systems on the target.

    PubMed

    Schnell, U; Dändliker, R; Gray, S

    1996-04-01

    We have extended the use of a dispersive white-light interferometer for absolute distance measurement to include effects of dielectric multilayer systems on the target. The phase of the ref lected wave changes as a function of wavelength and layer thickness and causes errors in the interferometric distance measurement. With dispersive white-light interferometry these effects can be measured in situ, and the correct mechanical distance can be determined. The effects of thin films deposited upon the target have been investigated for one and two layers (photoresist and SiO(2) upon Si). Experimental results show that the thicknesses of these layers can also be determined with an accuracy of the order of 10 nm.

  9. Absolute distance measurement with extension of nonambiguity range using the frequency comb of a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Jang, Yoon-Soo; Lee, Keunwoo; Han, Seongheum; Lee, Joohyung; Kim, Young-Jin; Kim, Seung-Woo

    2014-12-01

    We revisit the method of synthetic wavelength interferometry (SWI) for absolute measurement of long distances using the radio-frequency harmonics of the pulse repetition rate of a mode-locked femtosecond laser. Our intention here is to extend the nonambiguity range (NAR) of the SWI method using a coarse virtual wavelength synthesized by shifting the pulse repetition rate. The proposed concept of NAR extension is experimentally verified by measuring a ˜13-m distance with repeatability of 9.5 μm (root-mean-square). The measurement precision is estimated to be 31.2 μm in comparison with an incremental He-Ne laser interferometer. This extended SWI method is found to be well suited for long-distance measurements demanded in the fields of large-scale precision engineering, geodetic survey, and future space missions.

  10. Intensity evaluation using a femtosecond pulse laser for absolute distance measurement.

    PubMed

    Wu, Hanzhong; Zhang, Fumin; Li, Jianshuang; Cao, Shiying; Meng, Xiangsong; Qu, Xinghua

    2015-06-10

    In this paper, we propose a method of intensity evaluation based on different pulse models using a femtosecond pulse laser, which enables long-range absolute distance measurement with nanometer precision and large non-ambiguity range. The pulse cross-correlation is analyzed based on different pulse models, including Gaussian, Sech(2), and Lorenz. The DC intensity and the amplitude of the cross-correlation patterns are also demonstrated theoretically. In the experiments, we develop a new combined system and perform the distance measurements on an underground granite rail system. The DC intensity and amplitude of the interference fringes are measured and show a good agreement with the theory, and the distance to be determined can be up to 25 m using intensity evaluation, within 64 nm deviation compared with a He-Ne incremental interferometer, and corresponds to a relative precision of 2.7×10(-9). PMID:26192864

  11. Intensity evaluation using a femtosecond pulse laser for absolute distance measurement.

    PubMed

    Wu, Hanzhong; Zhang, Fumin; Li, Jianshuang; Cao, Shiying; Meng, Xiangsong; Qu, Xinghua

    2015-06-10

    In this paper, we propose a method of intensity evaluation based on different pulse models using a femtosecond pulse laser, which enables long-range absolute distance measurement with nanometer precision and large non-ambiguity range. The pulse cross-correlation is analyzed based on different pulse models, including Gaussian, Sech(2), and Lorenz. The DC intensity and the amplitude of the cross-correlation patterns are also demonstrated theoretically. In the experiments, we develop a new combined system and perform the distance measurements on an underground granite rail system. The DC intensity and amplitude of the interference fringes are measured and show a good agreement with the theory, and the distance to be determined can be up to 25 m using intensity evaluation, within 64 nm deviation compared with a He-Ne incremental interferometer, and corresponds to a relative precision of 2.7×10(-9).

  12. Global-scale location and distance estimates: common representations and strategies in absolute and relative judgments.

    PubMed

    Friedman, Alinda; Montello, Daniel R

    2006-03-01

    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevens's law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.

  13. Design and implementation of a vacuum compatible laser-basedsub-nm resolution absolute distance measurement gauge

    SciTech Connect

    Naulleau, Patrick P.; Denham, Paul E.; Rekawa, Senajith

    2004-02-16

    We describe the design and implementation of a vacuum compatible laser-based absolute distance measurement gauge with sub-nm resolution. The present system is compatible with operation in the 10{sup -8} Torr range and with some minor modifications could be used in the 10{sup -9} Torr range. The system is based on glancing incidence reflection and dual segmented diode detection. The system has been implemented as a focus sensor for extreme ultraviolet interferometry and microlithography experiments at Lawrence Berkeley National Laboratory's Advanced Light Source synchrotron radiation facility and 1{sigma} operational measurement noise floor of 0.26 nm has been demonstrated.

  14. Calibration of Fourier domain short coherence interferometer for absolute distance measurements.

    PubMed

    Montonen, R; Kassamakov, I; Hæggström, E; Österberg, K

    2015-05-20

    We calibrated and determined the measurement uncertainty of a custom-made Fourier domain short coherence interferometer operated in laboratory conditions. We compared the optical thickness of two thickness standards and three coverslips determined with our interferometer to the geometric thickness determined by SEM. Using this calibration data, we derived a calibration function with a 95% confidence level system uncertainty of (5.9×10(-3)r+2.3)  μm, where r is the optical distance in μm, across the 240 μm optical measurement range. The confidence limit includes contributions from uncertainties in the optical thickness, geometric thickness, and refractive index measurements as well as uncertainties arising from cosine errors and thermal expansion. The results show feasibility for noncontacting absolute distance characterization with micrometer-level accuracy. This instrument is intended for verifying the alignment of the discs of an accelerating structure in the possible future compact linear collider.

  15. Polarization and fold mirrors in application of the Leica Absolute Distance Meter

    NASA Astrophysics Data System (ADS)

    Sabatke, Derek; von Handorf, Robert; Sullivan, Joseph

    2009-08-01

    The polarization behavior of the Leica Geosystems absolute distance meter is investigated in order to understand measurement noise and dropouts sometimes observed when the instrument is used with fold mirrors. A Stokes- Mueller calculus analysis suggests retardance in the fold elements is a likely culprit. We establish the heuristic that for folds in a single plane, successful operation is obtained when the sum of the ellipsometric angle ▵ for each element in single pass is an integer multiple of 180°. The heuristic is validated experimentally, and found to have a tolerance in the range of +/-12° to hold distance standard deviations to 10μm. Strategies to achieve this condition include keeping angles of incidence near 90°, tuning with angle of incidence, and judicious selection of mirror coatings.

  16. Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement

    SciTech Connect

    Le Floch, Sebastien; Salvade, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

    2010-02-01

    We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of {+-} 50 {mu}m for a 1 ms acquisition time.

  17. Distance and absolute magnitudes of the brightest stars in the dwarf galaxy Sextans A

    NASA Technical Reports Server (NTRS)

    Sandage, A.; Carlson, G.

    1982-01-01

    In an attempt to improve present bright star calibration, data were gathered for the brightest red and blue stars and the Cepheids in the Im V dwarf galaxy, Sextans A. On the basis of a magnitude sequence measured to V and B values of about 22 and 23, respectively, the mean magnitudes of the three brightest blue stars are V=17.98 and B=17.88. The three brightest red supergiants have V=18.09 and B=20.14. The periods and magnitudes measured for five Cepheids yield an apparent blue distance modulus of 25.67 + or - 0.2, via the P-L relation, and the mean absolute magnitudes of V=-7.56 and B=-5.53 for the red supergiants provide additional calibration of the brightest red stars as distance indicators. If Sextans A were placed at the distance of the Virgo cluster, it would appear to have a surface brightness of 23.5 mag/sq arcec. This, together with the large angular diameter, would make such a galaxy easily discoverable in the Virgo cluster by means of ground-based surveys.

  18. Comb-calibrated frequency-modulated continuous-wave ladar for absolute distance measurements.

    PubMed

    Baumann, Esther; Giorgetta, Fabrizio R; Coddington, Ian; Sinclair, Laura C; Knabe, Kevin; Swann, William C; Newbury, Nathan R

    2013-06-15

    We demonstrate a comb-calibrated frequency-modulated continuous-wave laser detection and ranging (FMCW ladar) system for absolute distance measurements. The FMCW ladar uses a compact external cavity laser that is swept quasi-sinusoidally over 1 THz at a 1 kHz rate. The system simultaneously records the heterodyne FMCW ladar signal and the instantaneous laser frequency at sweep rates up to 3400 THz/s, as measured against a free-running frequency comb (femtosecond fiber laser). Demodulation of the ladar signal against the instantaneous laser frequency yields the range to the target with 1 ms update rates, bandwidth-limited 130 μm resolution and a ~100 nm accuracy that is directly linked to the counted repetition rate of the comb. The precision is <100 nm at the 1 ms update rate and reaches ~6 nm for a 100 ms average. PMID:23938965

  19. Low-coherence interferometric absolute distance gauge for study of MEMS structures

    NASA Astrophysics Data System (ADS)

    Walecki, Wojciech J.; Lai, Kevin; Pravdivtsev, Alexander; Souchkov, Vitali; Van, Phuc; Azfar, Talal; Wong, Tim; Lau, S. H.; Koo, Ann

    2005-01-01

    The most commonly employed tools for wafer thickness and topography metrology are based on capacitance method, which due to physical size of probes, and may not be suitable for direct measurement of multi-layer non-conductive wafers or Micro Electromechanical Systems (MEMS) structures. Recently developed that low coherence interferometry provides solution, which overcomes limitations of these methods. Selected MEMS applications including characterization of deep (high aspect) trenches and membrane structures have been also developed. The above listed applications were limited to measurements of relative distance between two optical interfaces in material transparent at the wavelength of probing radiation. Absolute distance gauging by fiber optic low coherence interferometer is difficult due to large thermal drift (of the order of 0.04 mm/K). We demonstrate that this drift is a result of thermal changes of refractive index of fiber optic glass. We present solution eliminating this drift is based on introduction of the additional reference plane in the signal arm of the Michelson interferometer. Use of this reference plane eliminates influence of changes of refractive index of glass fibers on result of measurement and improves thermal stability of low coherence interferometer by three orders of magnitude.

  20. Experiences of living with intermittent claudication.

    PubMed

    Egberg, Louise; Andreassen, Sissel; Mattiasson, Anne-Cathrine

    2012-03-01

    Intermittent claudication is a symptom caused by peripheral arterial disease (PAD) and is associated with pain, impaired mobility and loss of control. Walking ability is reduced due to the pain, and both physical and social functions are often negatively affected, which may lead to patients feeling they are a burden to others. An interview study using a qualitative descriptive design to describe experiences of living with intermittent claudication caused by PAD was carried out during Winter and Spring 2009/2010. Fifteen people suffering from intermittent claudication were interviewed, and the interviews were analyzed using qualitative thematic analysis. Intermittent claudication greatly affects daily living. Six themes were identified: "Experiencing discomfort in the legs," "Moving around in a new way," "Feeling inconvenient when forced to stop," "Missing previous life," "Incorporating intermittent claudication in daily life," and "To lead a strenuous life." The main theme was "Adjusting to a restricted life." The findings show that intermittent claudication has a major impact on daily life. Apart from the severity of symptoms, how the illness is experienced differs among patients, depending on how active the ill person is or wants to be. These findings suggest that increased knowledge about living with intermittent claudication is important to understand the effects on the ill person's life, as a complement to physical examinations when planning individual treatment. PMID:22321401

  1. ELLIPSOIDAL VARIABLE V1197 ORIONIS: ABSOLUTE LIGHT-VELOCITY ANALYSIS FOR KNOWN DISTANCE

    SciTech Connect

    Wilson, R. E.; Chochol, D.; KomzIk, R.; Van Hamme, W.; Pribulla, T.; Volkov, I.

    2009-09-01

    V1197 Orionis light curves from a long-term observing program for red giant binaries show ellipsoidal variation of small amplitude in the V and R{sub C} bands, although not clearly in U and B. Eclipses are not detected. All four bands show large irregular intrinsic variations, including fleeting quasi-periodicities identified by power spectra, that degrade analysis and may be caused by dynamical tides generated by orbital eccentricity. To deal with the absence of eclipses and consequent lack of astrophysical and geometrical information, direct use is made of the Hipparcos parallax distance while the V and R{sub C} light curves and (older) radial velocity curves are analyzed simultaneously in terms of absolute flux. The red giant's temperature is estimated from new spectra. This type of analysis, called Inverse Distance Estimation for brevity, is new and can also be applied to other ellipsoidal variables. Advantages gained by utilization of definite distance and temperature are discussed in regard to how radius, fractional lobe filling, and mass ratio information are expressed in the observations. The advantages were tested in solutions of noisy synthetic data. Also discussed and tested by simulations are ideas on the optimal number of light curves to be solved simultaneously under various conditions. The dim companion has not been observed or discussed in the literature but most solutions find its mass to be well below that of the red giant. Solutions show red giant masses that are too low for evolution to the red giant stage within the age of the Galaxy, although that result is probably an artifact of the intrinsic brightness fluctuations.

  2. The study of the nonlinear correction of the FMCW absolute distance measurement using frequency-sampling and precision analysis

    NASA Astrophysics Data System (ADS)

    Lu, Cheng; Gan, Yu; Chen, Fengdong; Liu, Bingguo; Zhuang, Zhitao; Xu, Xinke; Liu, Guodong

    2014-12-01

    This article uses the external cavity laser to realize FMCW high precision absolute distance measurement, as the external cavity laser owns the advantage of large tuning range of frequency. Firstly, aim at the problem of nonlinear tuning of the external cavity laser, a study of method of frequency-sampling has been shown. Secondly, in this article the mathematical model of the absolute dis tance measurement system has been established, and the sources of the errors of the FMCW absolute distance measurement has been analyzed, and the accuracy model has been established. Finally, a ball which is put at a distance about 3 meters is measured, and the random error is 0.3479μm, the standard uncertainty of measurement system is 0.3479μm+3.141Rppm.

  3. The reliability of differentiating neurogenic claudication from vascular claudication based on symptomatic presentation

    PubMed Central

    Nadeau, Mélissa; Rosas-Arellano, M. Patricia; Gurr, Kevin R.; Bailey, Stewart I.; Taylor, David C.; Grewal, Ruby; Lawlor, D. Kirk; Bailey, Chris S.

    2013-01-01

    Background Intermittent claudication can be neurogenic or vascular. Physicians use a profile based on symptom attributes to differentiate the 2 types of claudication, and this guides their investigations for diagnosis of the underlying pathology. We evaluated the validity of these symptom attributes in differentiating neurogenic from vascular claudication. Methods Patients with a diagnosis of lumbar spinal stenosis (LSS) or peripheral vascular disease (PVD) who reported claudication answered 14 questions characterizing their symptoms. We determined the sensitivity, specificity and positive and negative likelihood ratios (PLR and NLR) for neurogenic and vascular claudication for each symptom attribute. Results We studied 53 patients. The most sensitive symptom attribute to rule out LSS was the absence of “triggering of pain with standing alone” (sensitivity 0.97, NLR 0.050). Pain alleviators and symptom location data showed a weak clinical significance for LSS and PVD. Constellation of symptoms yielded the strongest associations: patients with a positive shopping cart sign whose symptoms were located above the knees, triggered with standing alone and relieved with sitting had a strong likelihood of neurogenic claudication (PLR 13). Patients with symptoms in the calf that were relieved with standing alone had a strong likelihood of vascular claudication (PLR 20.0). Conclusion The classic symptom attributes used to differentiate neurogenic from vascular claudication are at best weakly valid independently. However, certain constellation of symptoms are much more indicative of etiology. These results can guide general practitioners in their evaluation of and investigation for claudication. PMID:24284143

  4. Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly

    NASA Technical Reports Server (NTRS)

    Merle, Cormic; Wick, Eric; Hayden, Joseph

    2011-01-01

    This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics to make a differential distance measurement between a ring mirror on the reflective null assembly and individual PM segments. The ADM is located inside the same Pressure-Tight Enclosure (PTE) that houses the test interferometer. The PTE maintains the ADM and interferometer at ambient temperature and pressure so that they are not directly exposed to the telescope s harsh cryogenic and vacuum environment. This system takes advantage of the existing achromatic objective and reflective null assembly used by the test interferometer to direct four ADM beamlets to four PM segments through an optical path that is coincident with the interferometer beam. A mask, positioned on a linear slide, contains an array of 1.25 mm diameter circular subapertures that map to each of the 18 PM segments as well as six positions around the ring mirror. A down-collimated 4 mm ADM beam simultaneously covers 4 adjacent PM segment beamlets and one ring mirror beamlet. The radius, or spacing, of all 18 segments can be measured with the addition of two orthogonally-oriented scanning pentaprisms used to steer the ADM beam to any one of six different sub-aperture configurations at the plane of the ring mirror. The interferometer beam, at a wavelength of 687 nm, and the ADM beamlets, at a wavelength of 780 nm, pass through the objective and null so that the rays are normally incident on the parabolic PM surface. After reflecting off the PM, both the ADM and interferometer beams return to their respective

  5. Absolute thickness metrology with submicrometer accuracy using a low-coherence distance measuring interferometer.

    PubMed

    Zhao, Yang; Schmidt, Greg; Moore, Duncan T; Ellis, Jonathan D

    2015-09-01

    Absolute physical thickness across the sample aperture is critical in determining the index of a refraction profile from the optical path length profile for gradient index (GRIN) materials, which have a designed inhomogeneous refractive index. Motivated by this application, instrumentation was established to measure the absolute thickness of samples with nominally plane-parallel surfaces up to 50 mm thick. The current system is capable of measuring absolute thickness with 120 nm (1σ) repeatability and submicrometer expanded measurement uncertainty. Beside GRIN materials, this method is also capable of measuring other inhomogeneous and opaque materials. PMID:26368894

  6. Period-luminosity-metallicity relations, pulsation modes, absolute magnitudes, and distances for population 2 variable stars

    NASA Astrophysics Data System (ADS)

    Nemec, James M.; Nemec, Amanda F. Linnell; Lutz, Thomas E.

    1994-07-01

    Period-luminosity-metallicity (P-L-(Fe/H) relations are presented for RR Lyrae stars, Pop. II Cepheids, anomalous Cepheids and SX Phe stars pulsating in the fundamental (F) and first-overtone (H) modes. The relations were derived by fitting regression lines to the observed pulsation periods and mean B, V, and K magnitudes of over 1200 stars in approximately 40 stellar systems. Analysis of covariance methods, which allow the simultaneous computation of more than one P-L-(Fe/H) relation, were used to estimate the slopes and intercepts. Of the 24 possible P-L-(Fe/H) relations for the four kinds of stars, two pulsation modes, and three passbands considered here, 18 relations have been derived-the others could not be derived because of a lack of photometry in one or more of the three passbands. The slopes for the F and H pulsators were tested for departures from equality for all types of stars and passbands; the results suggest that the observations are consistent with the assumption that, for each kind of star (except possibly the Pop. II Cepheids), the P-L-(Fe/h) relations for the F and H pulsation modes are parallel but vertically offset, with a family of lines corresponding to a range of metallicities. Pulsation modes and absolute magnitudes are presented for the non-RR Lyrae variable stars considered in the analysis, and distances are estimated for the program clusters. It is well established from previous studies that the P-L relations for RR Lyrae stars are approximately flat for the B passband, and have a slope delta mk/ delta log P approximately 2.4 for the K passband. We recover these slopes and find that the P-L-(Fe/H) relation in V has an intermediate slope, delta mv/delta log P = -0.52 plus or minus 0.11. A similar dependence of slope on passband is seen for classical Cepheids (see Madore & Freedman, PASP, 103, 933 (1991). The available B, V photometry for approximately 40 of the known globular cluster Cepheids are found to be consistent with Arp's AJ, 60

  7. Absolute distance measurement by multi-heterodyne interferometry using a frequency comb and a cavity-stabilized tunable laser.

    PubMed

    Wu, Hanzhong; Zhang, Fumin; Liu, Tingyang; Balling, Petr; Qu, Xinghua

    2016-05-20

    In this paper, we develop a multi-heterodyne system capable of absolute distance measurement using a frequency comb and a tunable diode laser locked to a Fabry-Perot cavity. In a series of subsequent measurements, numerous beat components can be obtained by downconverting the optical frequency into the RF region with multi-heterodyne interferometry. The distances can be measured via the mode phases with a series of synthetic wavelengths. The comparison with the reference interferometer shows an agreement within 1.5 μm for the averages of five measurements and 2.5 μm for the single measurement, which is at the 10-8 relative precision level. PMID:27411152

  8. THE DYNAMICAL DISTANCE, RR LYRAE ABSOLUTE MAGNITUDE, AND AGE OF THE GLOBULAR CLUSTER NGC 6266

    SciTech Connect

    McNamara, Bernard J.; McKeever, Jean E-mail: jeanm12@nmsu.edu

    2011-11-15

    The internal proper motion dispersion of NGC 6266 was measured using Hubble Space Telescope Wide Field Planetary Camera 2 images with an epoch difference of eight years. The dispersion was found to be 0.041 {+-} 0.001 arcsec century{sup -1}. This value was then equated to the cluster's radial velocity dispersion of 13.7 {+-} 1.1 km s{sup -1} to yield a distance to NGC 6266 of 7054 {+-} 583 pc. Based on this distance we find that the NGC 6266 RR Lyrae stars have M{sub V} = 0.51 {+-} 0.18 mag. This magnitude is in good agreement with that predicted by the M{sub V} versus [Fe/H] relation found by Benedict et al. Using an average [Fe/H] of -1.25 for NGC 6266, their relation predicts M{sub V} = 0.49 {+-} 0.06. Based on the RR Lyrae M{sub V} versus age relation determined by Chaboyer et al., we estimate that NGC 6266 has an age of 11.4 {+-} 2.2 Gyr.

  9. Close-range photogrammetry with light field camera: from disparity map to absolute distance.

    PubMed

    Yang, Peng; Wang, Zhaomin; Yan, Yizhen; Qu, Weijuan; Zhao, Hongying; Asundi, Anand; Yan, Lei

    2016-09-20

    A new approach to measure the 3D profile of a texture object is proposed utilizing light field imaging, in which three key steps are required: a disparity map is first obtained by detecting the slopes in the epipolar plane image with the multilabel technique; the intrinsic parameters of the light field camera are then extracted by camera calibration; at last, the relationship between disparity values and real distances is built up by depth calibration. In the last step, a linear calibration method is proposed to achieve accurate results. Furthermore, the depth error is also investigated and compensated for by reusing the checkerboard pattern. The experimental results are in good agreement with the 3D models, and also indicate that the light field imaging is a promising 3D measurement technique. PMID:27661572

  10. [Marks on clothing and skin in absolutely and relatively close distance gunshots with fright weapons].

    PubMed

    Nadjem, H; Bohnert, M; Schley, K; Pollak, S

    1996-01-01

    Based on an actual case to be examined-the victim had sustained burning and powder tattooing of the abdominal skin--test shots were performed with blank cartridge guns (Mauser and Umarex revolvers, cal. 380) in order to study the changes occurring on textiles in the area of contact and close range shots. As expected, the extent of burning and smoke soiling depended on whether the propellant of the blank cartridges consisted of nitrocellulose (Nc) or black powder. At the same distance the smokeless nitro-powder caused less soot soiling and burning than black powder. Contact or near contact shots produced tear-like tissue damages due to the pressure of the discharged muzzle gases. When black powder cartridges were used, burn holes larger than the caliber were observed; with Nc blank cartridges the thermal effects were most pronounced if textiles made of thermolabile synthetics were shot at. PMID:8929126

  11. Kinematic adaptations to ischemic pain in claudicants during continuous walking.

    PubMed

    Mockford, Katherine A; Vanicek, Natalie; Jordan, Alastair; Chetter, Ian C; Coughlin, Patrick A

    2010-07-01

    Intermittent claudication has been associated with impaired gait and balance. The study aim was to compare gait adaptations over time between claudicants classified with good versus poor balance. Kinematic data were collected from 24 claudicants during continuous walking. Balance was assessed using; Timed Up and Go test (TUG), and Sensory Organisation (SOT) and Motor Control (MCT) Tests using NeuroCom Equitest®. 'Good balance' (GB) was operationally defined as those claudicants achieving normal scores on at least 2 of 3 tests whereas 'poor balance' (PB) claudicants achieved normal scores on 0 or 1 test. Temporal-spatial and sagittal plane joint kinematics were analysed at three time intervals; 'no pain' (prior to onset), 'initial pain' and 'maximal pain' (unable to continue walking). A two-way mixed design ANOVA was performed. Claudicants demonstrated a significant decrease in walking speed, step frequency and increased time in double support (p<0.05). Inter-group analysis showed no differences between GB and PB on any temporal-spatial or kinematic parameters (p>0.05). There was no significant time and group interaction for any temporal-spatial or kinematic variable except hip flexion. GB claudicants demonstrated increased hip flexion as pain progressed but this adaptive strategy was not seen in PB claudicants. Claudicants make adaptations to walking by slowing (down) when in pain. Differences between GB and PB were not seen in temporal-spatial or ankle, knee and pelvic kinematic gait parameters. However adaptation to pain in GB claudicants involved a hip strategy, not seen in PB claudicants. PMID:20678939

  12. Effects of exercise training on common femoral artery blood flow in patients with intermittent claudication.

    PubMed

    Johnson, E C; Voyles, W F; Atterbom, H A; Pathak, D; Sutton, M F; Greene, E R

    1989-11-01

    Exercise training is a commonly used rehabilitative therapy for patients with intermittent claudication (IC). However, it is not known whether blood flow through the major conduit vessel of the leg, the common femoral artery (CFA), increases with exercise training. We tested the hypothesis that peak CFA blood flow will increase with a supervised, lengthy, and individualized exercise training program. Subjects were 10 IC patients (eight men, two women) with a mean age of 61 +/- 7 (mean +/- SD) years who had either aortoiliac (n = 7) or femoropopliteal (n = 3) stenosis. Using noninvasive Doppler flowmetry, we measured CFA blood flow and ankle pressure at rest and after a maximum symptom-limited graded treadmill test before (T1) and after 3 (T2) and 5 (T3) months of exercise training. Variables were measured in the supine and upright postures at rest and during recovery. Total walking distance and claudication distance on the treadmill were determined for T1, T2, and T3. After training, CFA blood flow and ankle pressure were not significantly higher at rest or at 1 minute after exercise compared with pretraining despite significant increases in claudication and total walking distances. The rate of CFA blood flow recovery was slower at T3, suggesting the accrual of a larger metabolic debt during exercise due to more work performed. We conclude that changes in CFA blood flow are not responsible for measured changes in performance with exercise training in IC patients. PMID:2680161

  13. Interference peak detection based on FPGA for real-time absolute distance ranging with dual-comb lasers

    NASA Astrophysics Data System (ADS)

    Ni, Kai; Dong, Hao; Zhou, Qian; Xu, Mingfei; Li, Xinghui; Wu, Guanhao

    2015-08-01

    Absolute distance measurement using dual femtosecond comb lasers can achieve higher accuracy and faster measurement speed, which makes it more and more attractive. The data processing flow consists of four steps: interference peak detection, fast Fourier transform (FFT), phase fitting and compensation of index of refraction. A realtime data processing system based on Field-Programmable Gate Array (FPGA) for dual-comb ranging has been newly developed. The design and implementation of the interference peak detection algorithm by FPGA and Verilog language is introduced in this paper, which is viewed as the most complicated part and an important guarantee for system precision and reliability. An adaptive sliding window for scanning is used to detect peaks. In the process of detection, the algorithm stores 16 sample data as a detection unit and calculates the average of each unit. The average result is used to determine the vertical center height of the sliding window. The algorithm estimates the noise intensity of each detection unit, and then calculates the average of the noise strength of successive 128 units. The noise average is used to calculate the signal to noise ratio of the current working environment, which is used to adjust the height of the sliding window. This adaptive sliding window helps to eliminate fake peaks caused by noise. The whole design is based on the way of pipeline, which can improves the real-time throughput of the overall peak detection module. Its execution speed is up to 140MHz in the FPGA, and the peak can be detected in 16 clock cycle when it appears.

  14. [Disease picture of neural intermittent claudication in lumbar spinal stenosis].

    PubMed

    Krüger, J; Tönnies, H; Senff, H

    1985-05-01

    The article reports on 56 patients on whom operation was performed for neurogenic intermittent claudication up to the end of 1983. The diagnostic, operative, and post-operative results are described in detail.

  15. Intermittent claudication: new targets for drug development.

    PubMed

    Brass, Eric P

    2013-07-01

    Peripheral artery disease (PAD) is the result of extensive atherosclerosis in the arterial supply to the lower extremities. PAD is associated with increased systemic cardiovascular morbidity and mortality as well as substantial disability due to walking impairment. Claudication is the classic symptom of leg pain with walking that is relieved by rest, but patients with PAD without typical claudication also have a walking limitation. Treatment of the patient with PAD is directed towards reducing cardiovascular risk and improving exercise capacity. The pathophysiology of the physical impairment is complex as changes in the muscle distal to the arterial stenoses contribute to the limitations. Current treatment options to improve exercise performance have limitations emphasizing the need for new pharmacotherapies for this highly prevalent condition. The multifactorial contributors to the exercise impairment in PAD suggest potential targets for novel drug therapies. Advances in understanding angiogenesis make pharmacologic revascularization possible. However, ensuring that new blood vessels develop in a distribution relevant to the clinical impairment remains a challenge. Skeletal muscle metabolism and its regulation are altered in patients with PAD and strategies to improve the efficient oxidation of fuel substrates may improve muscle function. PAD is associated with increased oxidative stress which may result in injury to the muscle microvasculature and myocyte. Minimizing this oxidative stress by enhancing cellular defense mechanisms, administration of anti-inflammatory agents or by providing antioxidants, could prevent oxidative injury. Given the central role of atherosclerosis in the flow limitation, therapies to induce regression of atherosclerotic lesions could result in improved blood flow and oxygen delivery. Drugs targeting the distribution of blood flow in the microcirculatory environment of the muscle have the potential to better match oxygen delivery with

  16. Impact of claudication and its treatment on quality of life.

    PubMed

    Spronk, Sandra; White, John V; Bosch, Johanna L; Hunink, M G Myriam

    2007-03-01

    Improvement in quality of life is the ultimate goal of healthcare for the treatment of intermittent claudication. Until recently, the measures of success after therapy were those derived from the vascular laboratory, including ankle-brachial indices and ankle and toe pressures. There are now several validated and reliable survey tools that can assess patient-reported quality of life in a generic or disease-specific manner. Major survey instruments are reviewed. The information gathered through these quality-of-life assessment tools is important to all those involved in the care of patients with peripheral arterial disease. Although claudication is neither life- nor limb-threatening, it has a significant negative impact on quality of life, as measured by these instruments. Patients so afflicted report more bodily pain, worse physical function, and worse perceived health, in addition to limited walking ability. These measures of quality of life do not correlate with standard parameters of ankle-brachial index or ankle pressures. Treatment of the claudicant with exercise therapy and percutaneous or open revascularization also impacts quality of life. Each of these modalities is capable of improving quality of life, but some are associated with decline over time. The major benefits and risks to quality of life of these specific forms of treatment for the claudicant are reviewed. This data demonstrates that patients suffering from symptoms of intermittent claudication are best served by therapies that address their major self-reported impediments to quality of life.

  17. Upper versus lower limb exercise training in patients with intermittent claudication: a systematic review.

    PubMed

    Tompra, Nefeli; Foster, Carl; Sanchis-Gomar, Fabian; de Koning, Jos J; Lucia, Alejandro; Emanuele, Enzo

    2015-04-01

    Lower extremity (LE) exercise training has been shown to contribute to improvements in Maximum Walking Distance (MWD), Claudication Distance (CD), peak oxygen uptake (VO2peak) and Quality of Life (QoL) in patients with intermittent claudication (IC). However, little is known regarding the efficacy of upper extremity (UE) exercise training in comparison to the widely used LE training. The objective of this systematic literature review is to identify and synthesize the available literature on the effects of UE versus LE exercises using the International Classification of Functioning (ICF) conceptual framework. A total of 6 randomized controlled trials comparing UE to LE exercises were included in this study. Two of the articles were considered to be of high quality using the PEDro grading list. Both UE and LE training groups demonstrated significant improvements in MWD, CD, VO2peak and QoL in comparison to the control group but LE was not better than UE training. This supports the use of UE training as an alternative to LE, which could provide symptomatic relief to patients with IC without the discomfort caused during the LE training.

  18. Dispersive white light combined with a frequency-modulated continuous-wave interferometer for high-resolution absolute measurements of distance.

    PubMed

    Rovati, L; Minoni, U; Docchio, F

    1997-06-15

    A nonincremental interferometer for the absolute measurement of distances is presented. The measuring technique is based on both dispersive white-light (DWL) interferometry and frequency-modulated continuous-wave (FMCW) interferometry. The proposed configuration integrates both techniques in the same interferometer by use of a single laser diode. This solution enables the results from the coarse measurements from the FMCW interferometer to be combined with the fine readouts from the DWL interferometer. Preliminary experimental results confirm the capability of the system to combine the advantages of the two techniques. PMID:18185683

  19. Lumbar epidural varices: An unusual cause of lumbar claudication

    PubMed Central

    Subbiah, Meenakshisundaram; Yegumuthu, Krishnan

    2016-01-01

    Lumbar epidural varices can also present with radiculopathy similar to acute intervertebral disc prolapse (IVDP). However as the magnetic resonance imaging (MRI) in these patients are usually normal without significant compressive lesions of the nerve roots, the diagnosis is commonly missed or delayed leading to persistent symptoms. We present a rare case of acute severe unilateral claudication with a normal MRI unresponsive to conservative management who was treated surgically. The nerve root on the symptomatic side was found to be compressed by large anterior epidural varices secondary to an abnormal cranial attachment of ligamentum flavum. Decompression of the root and coagulation of the varices resulted in complete pain relief. To conclude, lumbar epidural varices should be considered in the differential diagnosis of acute onset radiculopathy and claudication in the absence of significant MRI findings. PMID:27512228

  20. Sub-micron absolute distance measurements in sub-millisecond times with dual free-running femtosecond Er fiber-lasers.

    PubMed

    Liu, Tze-An; Newbury, Nathan R; Coddington, Ian

    2011-09-12

    We demonstrate a simplified dual-comb LIDAR setup for precision absolute ranging that can achieve a ranging precision of 2 μm in 140 μs acquisition time. With averaging, the precision drops below 1 μm at 0.8 ms and below 200 nm at 20 ms. The system can measure the distance to multiple targets with negligible dead zones and a ranging ambiguity of 1 meter. The system is much simpler than a previous coherent dual-comb LIDAR because the two combs are replaced by free-running, saturable-absorber-based femtosecond Er fiber lasers, rather than tightly phase-locked combs, with the entire time base provided by a single 10-digit frequency counter. Despite the simpler design, the system provides a factor of three improved performance over the previous coherent dual comb LIDAR system.

  1. Sub-micron absolute distance measurements in sub-millisecond times with dual free-running femtosecond Er fiber-lasers.

    PubMed

    Liu, Tze-An; Newbury, Nathan R; Coddington, Ian

    2011-09-12

    We demonstrate a simplified dual-comb LIDAR setup for precision absolute ranging that can achieve a ranging precision of 2 μm in 140 μs acquisition time. With averaging, the precision drops below 1 μm at 0.8 ms and below 200 nm at 20 ms. The system can measure the distance to multiple targets with negligible dead zones and a ranging ambiguity of 1 meter. The system is much simpler than a previous coherent dual-comb LIDAR because the two combs are replaced by free-running, saturable-absorber-based femtosecond Er fiber lasers, rather than tightly phase-locked combs, with the entire time base provided by a single 10-digit frequency counter. Despite the simpler design, the system provides a factor of three improved performance over the previous coherent dual comb LIDAR system. PMID:21935219

  2. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  3. High prevalence of known and unknown pulmonary diseases in patients with claudication during exercise oximetry

    PubMed Central

    Colas-Ribas, Christophe; Signolet, Isabelle; Henni, Samir; Feuillloy, Mathieu; Gagnadoux, Frédéric; Abraham, Pierre

    2016-01-01

    Abstract The prevalence of pulmonary disease in patients with peripheral artery disease (PAD) has not been extensively studied. Recent evidence has shown that ∼20% of the patients have an atypical chest transcutaneous oxygen pressure (TcpO2) pattern during exercise, which suggests walking-induced hypoxemia. The main objectives of this study were to: (1) describe in a retrospective way the characteristics of the patients suffering from claudication, who attended a treadmill testing in our laboratory, (2) assess the prevalence of known or unknown pulmonary disease. The second aim of this study was to evaluate the impact of the therapeutic interventions on the walking capacities, after treatment, of the eventually detected pulmonary disorders. We retrospectively analyzed 1482 exercise TcpO2 test results. Patients that had no history of pulmonary disease, but either reported severe dyspnea or showed atypical profiles on their chest exercise-TcpO2, were advised to refer to the department of pneumology for additional investigations. In addition to the 166 patients with a history of pulmonary disease, 158 patients were suspected of unknown pulmonary disease from the result of their TcpO2 test. Many patients (n = 99/158, 62.7%) did not attend a pulmonologist visit. A pulmonary disease was established in 55 (93.2%) of the other 59 patients. Obstructive sleep apnea syndrome (OSAS) was the one and only diagnosis retained in 42/59 patients (71.2%). Among the 47 patients who had a second evaluation of their walking capacity on treadmill, 38 had treatment of the pulmonary disease found, vascular surgery treatment or a severe restricted diet, 9 had no treatment. Only the “treated” group showed a significant improvement in the maximal walking distance on treadmill between the 2 evaluations, 313 ± 251 m to 433 ± 317 m (P = 0.03). This retrospective pilot study underlines the high prevalence of both known and unknown pulmonary disease in patients whose

  4. Patient Characteristics and Comorbidities Influence Walking Distances in Symptomatic Peripheral Arterial Disease: A Large One-Year Physiotherapy Cohort Study

    PubMed Central

    Dörenkamp, Sarah; Mesters, Ilse; van Breukelen, Gerard

    2016-01-01

    Objectives The aim of this study is to investigate the association between age, gender, body-mass index, smoking behavior, orthopedic comorbidity, neurologic comorbidity, cardiac comorbidity, vascular comorbidity, pulmonic comorbidity, internal comorbidity and Initial Claudication Distance during and after Supervised Exercise Therapy at 1, 3, 6 and 12 months in a large sample of patients with Intermittent Claudication. Methods Data was prospectively collected in standard physiotherapy care. Patients received Supervised Exercise Therapy according to the guideline Intermittent Claudication of the Royal Dutch Society for Physiotherapy. Three-level mixed linear regression analysis was carried out to analyze the association between patient characteristics, comorbidities and Initial Claudication Distance at 1, 3, 6 and 12 months. Results Data from 2995 patients was analyzed. Results showed that being female, advanced age and a high body-mass index were associated with lower Initial Claudication Distance at all-time points (p = 0.000). Besides, a negative association between cardiac comorbidity and Initial Claudication Distance was revealed (p = 0.011). The interaction time by age, time by body-mass index and time by vascular comorbidity were significantly associated with Initial Claudication Distance (p≤ 0.05). Per year increase in age (range: 33–93 years), the reduction in Initial Claudication Distance was 8m after 12 months of Supervised Exercise Therapy. One unit increase in body-mass index (range: 16–44 kg/m2) led to 10m less improvement in Initial Claudication Distance after 12 months and for vascular comorbidity the reduction in improvement was 85m after 12 months. Conclusions This study reveals that females, patients at advanced age, patients with a high body-mass index and cardiac comorbidity are more likely to show less improvement in Initial Claudication Distances (ICD) after 1, 3, 6 and 12 months of Supervised Exercise Therapy. Further research should

  5. How Well Do Randomized Controlled Trials Reflect Standard Care: A Comparison between Scientific Research Data and Standard Care Data in Patients with Intermittent Claudication undergoing Supervised Exercise Therapy

    PubMed Central

    Mesters, E. P. E.; Nijhuis-van der Sanden, M. W. G.; Teijink, J. A. W.; de Bie, R. A.

    2016-01-01

    Objective The aim of the present study was to assess the degree and impact of patient selection of patients with intermittent claudication undergoing supervised exercise therapy in Randomized Controlled Trials (RCTs) by describing commonly used exclusion criteria, and by comparing baseline characteristics and treatment response measured as improvement in maximum walking distance of patients included in RCTs and patients treated in standard care. Methods We compared data from RCTs with unselected standard care data. First, we systematically reviewed RCTs that investigated the effect of supervised exercise therapy in patients with intermittent claudication. For each of the RCTs, we extracted and categorized the eligibility criteria and their justifications. To assess whether people in RCTs (n = 1,440) differed from patients treated in daily practice (n = 3,513), in terms of demographics, comorbidity and walking capacity, we assessed between group-differences using t-tests. To assess differences in treatment response, we compared walking distances at three and six months between groups using t-tests. Differences of ≥15% were set as a marker for a clinically relevant difference. Results All 20 included RCTs excluded large segments of patients with intermittent claudication. One-third of the RCTs eligibility criteria were justified. Despite, the numerous eligibility criteria, we found that baseline characteristics were largely comparable. A statistically significant and (borderline) clinically relevant difference in treatment response after three and six months between trial participants and standard care patients was found. Improvements in maximum walking distance after three and six months were significantly and clinically less in trial participants. Conclusions The finding that baseline characteristics of patients included in RCTs and patients treated in standard care were comparable, may indicate that RCT eligibility criteria are used implicitly by professionals

  6. Cystic adventitial disease of the popliteal artery: an infrequent cause of intermittent claudication

    PubMed Central

    Kauffman, Paulo; Kuzniec, Sergio; Sacilotto, Roberto; Teivelis, Marcelo Passos; Wolosker, Nelson; Tachibana, Adriano

    2014-01-01

    Intermittent claudication is frequently associated with atherosclerotic disease, but differential diagnosis must be sought in patients with no traditional risk factors. Cystic adventitial disease, of unknown etiology, most frequently affects the popliteal artery, and occasionally presents as intermittent claudication. We report a case of this disease and the surgical treatment, and discuss some aspects related to etiopathogenesis, diagnosis and treatment of this condition. PMID:25167336

  7. Relief of Buttock Claudication by Percutaneous Recanalization of an Occluded Superior Gluteal Artery

    SciTech Connect

    Senechal, Quentin; Auguste, Mario C.; Louail, Bertrand; Lagneau, Pierre; Pernes, Jean Marc

    2000-03-15

    We report a case of a woman presenting with right severe buttock claudication and normal neurological and osteoarticular examination, in whom a guidewire recanalization and percutaneous transluminal angioplasty (PTA) of an occluded right superior gluteal artery (SGA) has provided relief of her symptoms. To our knowledge, this is the first report of percutaneous recanalization of the SGA. PTA can be considered the treatment of choice for buttock claudication caused by SGA stenosis or occlusion.

  8. [Intermittent claudication and quality of life. Psychometric validation of the French version of the CLAU-S questionnaire].

    PubMed

    Boccalon, H; Lehert, P; Comte, S

    2000-04-01

    CLAU-S is a disease-specific quality of life (QoL) scale for patients with intermittent claudication due to peripheral arterial disease of the lower limbs. Initially developed in Germany, the scale has been translated into French according to classical forward/backward methodology. The objective of this study was to test the validity of the French version of CLAU-S. In its current format, the CLAU-S scale evaluates 5 dimensions: "Daily Living"; "Pain"; "Social Life"; "Disease-specific anxiety"; and "Mood", for a total of 47 items. The QoL scores and clinical findings in 157 patients with intermittent claudication were analysed. Validation of the convergence and discriminatory power of the scale were confirmed. Analysis of structural validity showed grouping of items in accordance with initial scale construction and a clear separation between the different dimensions. Analysis of the internal reliability of the questionnaire confirmed the good internal coherence of these dimensions. Reproducibility of the scores over time was confirmed by test-retest analysis. In addition to the actual validation of CLAU-S, a new, innovative mathematical technique called Structural Modelling Equations was used on this QoL instrument. It related the causal structure of the QoL components in peripheral arterial disease of the lower limbs (stage 2). An indisputable causal relationship was demonstrated between clinical parameters, particularly walking distance, and the QoL components. The classical symptom-deficit-disability causal structure of disease- specific QoL questionnaires was also studied. In particular, we found an essential relationship between the Daily Living dimension and, to a lesser extent, the Social Life activities and Disease- specific anxiety dimension, and QoL. The Pain dimension proved to be an explanatory variable of the other QoL components without being directly related to QoL. Finally, the Mood dimension was a resultant variable of QoL and not an explanatory

  9. Cost‐Effectiveness of Supervised Exercise, Stenting, and Optimal Medical Care for Claudication: Results From the Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) Trial

    PubMed Central

    Reynolds, Matthew R.; Apruzzese, Patricia; Galper, Benjamin Z.; Murphy, Timothy P.; Hirsch, Alan T.; Cutlip, Donald E.; Mohler, Emile R.; Regensteiner, Judith G.; Cohen, David J.

    2014-01-01

    Background Both supervised exercise (SE) and stenting (ST) improve functional status, symptoms, and quality of life compared with optimal medical care (OMC) in patients with claudication. The relative cost‐effectiveness of these strategies is not well defined. Methods and Results The Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) study randomized patients with claudication due to aortoiliac stenosis to a 6‐month SE program, to ST, or to OMC. Participants who completed 6‐month follow‐up (n=98) were included in a health economic analysis through 18 months. Costs were assessed using resource‐based methods and hospital billing data. Quality‐adjusted life‐years were estimated using the EQ‐5D. Markov modeling based on the in‐trial results was used to explore the impact of assumptions about the longer term durability of observed differences in quality of life. Through 18 months, mean healthcare costs were $5178, $9804, and $14 590 per patient for OMC, SE, and ST, respectively. Measured quality‐adjusted life‐years through 18 months were 1.04, 1.16, and 1.20. In our base case analysis, which assumed that observed differences in quality of life would dissipate after 5 years, the incremental cost‐effectiveness ratios were $24 070 per quality‐adjusted life‐year gained for SE versus OMC, $41 376 for ST versus OMC, and $122 600 for ST versus SE. If the treatment effect of ST was assumed to be more durable than that of SE, the incremental cost‐effectiveness ratio for ST versus SE became more favorable. Conclusions Both SE and ST are economically attractive by US standards relative to OMC for the treatment of claudication in patients with aortoiliac disease. ST is more expensive than SE, with uncertain incremental benefit. Clinical Trial Registration URL: www.clinicaltrials.gov, Unique identifier: NCT00132743. PMID:25389284

  10. Imaging popliteal artery disease in young adults with claudication: self-assessment module.

    PubMed

    Chew, Felix S; Bui-Mansfield, Liem T

    2007-09-01

    The educational objectives of this self-assessment module on imaging popliteal artery disease in young adults with intermittent claudication are for the participant to exercise, self-assess, and improve his or her knowledge of the imaging and clinical features of popliteal artery entrapment syndrome, cystic adventitial disease,and masses associated with popliteal artery obstruction.

  11. Iliac Artery Stent Placement Relieves Claudication in Patients with Iliac and Superficial Femoral Artery Lesions

    SciTech Connect

    Ichihashi, Shigeo Higashiura, Wataru; Itoh, Hirofumi; Sakaguchi, Shoji; Kichikawa, Kimihiko

    2013-06-15

    Purpose. To evaluate the efficacy of iliac artery stent placement for relief of claudication in patients with both iliac and superficial femoral artery (SFA) lesions. Methods. Stent placement for only iliac artery occlusive disease was performed in 94 limbs (74 patients) with both iliac and SFA occlusive disease on the same limb. All procedures were performed because intermittent claudication did not improve after continuation of antiplatelet medication therapy and home-based exercise for 3 months. Rutherford classification was 2 in 20 limbs and 3 in 74 limbs. Patients with critical limb ischemia were excluded. Median duration of follow-up was 40 months. Primary patency rates of the iliac stent, clinical improvement rates, and risk factors for requiring additional SFA procedures were evaluated. Results. Primary patency rates of the iliac stent at 1, 3, 5, and 7 years were 97, 93, 79, and 79 %, respectively. The initial clinical improvement rate was 87 %. Continued clinical improvement rates at 1, 3, 5, and 7 years were 87, 81, 69, and 66 %, respectively. SFA Trans-Atlantic Inter-Society Consensus (TASC) II C/D lesion was a significant risk factor for requiring additional SFA procedures. Conclusion. Intermittent claudication was relieved by iliac stent placement in most patients with both iliac and SFA lesions. Thus, the indications for treatment of the SFA intended for claudicants should be evaluated after treatment of the iliac lesion.

  12. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  13. Blood viscosity during long-term treatment with ticlopidine in patients with intermittent claudication. A double-blind study.

    PubMed

    Fagher, B; Persson, S; Persson, G; Larsson, H

    1993-04-01

    The aim was to test within a randomized, double-blind trial whether the antiaggregant drug ticlopidine might reduce blood viscosity as has been claimed. Sixteen patients with intermittent claudication were studied before and after three years of treatment with ticlopidine, 500 mg/day, or placebo. At baseline, the viscosity values were significantly higher as compared with a reference group of healthy subjects. Whole-blood viscosity, measured at four different shear rates at hematocrit adjusted to a standard 40%, decreased significantly at follow-up, with no difference between ticlopidine treatment and placebo. Hematocrit showed a slight increase in the placebo group. The viscosity parameters were unrelated to lower limb blood flow variables, ankle/brachial index, and walking distances. The mechanism behind the overall decrease in whole-blood viscosity is obscure but could possibly be explained by lifestyle changes. Smoking habits were, however, unaltered. Since plasma viscosity remained increased, it might indicate that some erythrocyte factor, notably red cell aggregability and deformability, had improved. It is concluded that ticlopidine had no long-term effect on blood viscosity.

  14. Computerized dynamic posturography for postural control assessment in patients with intermittent claudication.

    PubMed

    Vanicek, Natalie; King, Stephanie A; Gohil, Risha; Chetter, Ian C; Coughlin, Patrick A

    2013-01-01

    Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic conditions. As part of a diagnostic assessment, the early detection of postural deficits is important so that appropriate and targeted interventions can be prescribed. The Sensory Organization Test (SOT) on the EquiTest determines an individual's use of the sensory systems (somatosensory, visual, and vestibular) that are responsible for postural control. Somatosensory and visual input are altered by the calibrated sway-referenced support surface and visual surround, which move in the anterior-posterior direction in response to the individual's postural sway. This creates a conflicting sensory experience. The Motor Control Test (MCT) challenges postural control by creating unexpected postural disturbances in the form of backwards and forwards translations. The translations are graded in magnitude and the time to recover from the perturbation is computed. Intermittent claudication, the most common symptom of peripheral arterial disease, is characterized by a cramping pain in the lower limbs and caused by muscle ischemia secondary to reduced blood flow to working muscles during physical exertion. Claudicants often display poor balance, making them susceptible to falls and activity avoidance. The Ankle Brachial Pressure Index (ABPI) is a noninvasive method for indicating the presence of peripheral arterial disease and intermittent claudication, a common symptom in the lower extremities. ABPI is measured as the highest systolic pressure from either the dorsalis pedis or posterior tibial artery divided by the highest brachial artery systolic pressure from either arm. This paper will focus on the use of computerized dynamic posturography in the assessment of balance in claudicants. PMID:24378378

  15. Computerized Dynamic Posturography for Postural Control Assessment in Patients with Intermittent Claudication

    PubMed Central

    Vanicek, Natalie; King, Stephanie A.; Gohil, Risha; Chetter, Ian C.; Coughlin, Patrick A

    2013-01-01

    Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic conditions. As part of a diagnostic assessment, the early detection of postural deficits is important so that appropriate and targeted interventions can be prescribed. The Sensory Organization Test (SOT) on the EquiTest determines an individual's use of the sensory systems (somatosensory, visual, and vestibular) that are responsible for postural control. Somatosensory and visual input are altered by the calibrated sway-referenced support surface and visual surround, which move in the anterior-posterior direction in response to the individual's postural sway. This creates a conflicting sensory experience. The Motor Control Test (MCT) challenges postural control by creating unexpected postural disturbances in the form of backwards and forwards translations. The translations are graded in magnitude and the time to recover from the perturbation is computed. Intermittent claudication, the most common symptom of peripheral arterial disease, is characterized by a cramping pain in the lower limbs and caused by muscle ischemia secondary to reduced blood flow to working muscles during physical exertion. Claudicants often display poor balance, making them susceptible to falls and activity avoidance. The Ankle Brachial Pressure Index (ABPI) is a noninvasive method for indicating the presence of peripheral arterial disease and intermittent claudication, a common symptom in the lower extremities. ABPI is measured as the highest systolic pressure from either the dorsalis pedis or posterior tibial artery divided by the highest brachial artery systolic pressure from either arm. This paper will focus on the use of computerized dynamic posturography in the assessment of balance in claudicants. PMID:24378378

  16. A Comparison of Cilostazol and Pentoxifylline for Treating Intermittent Claudication

    NASA Technical Reports Server (NTRS)

    Dawson, David L.; Cutler, Bruce S.; Hiatt, William R.; Hobson, Robert W., II; Martin, John D.; Bortey, Enoch B.; Forbes, William P.; Strandness, D. Eugene, Jr.; Homick, Jerry L. (Technical Monitor)

    1999-01-01

    A randomized, double-blind, placebo-controlled, parallel-group, phase III multicenter trial was performed to evaluate the relative efficacy and safety of cilostazol and pentoxifylline. The study included 54 outpatient vascular clinics, including sites at Air Force, Veterans Affairs, tertiary care, and university hospitals in the United States. Of 922 consenting patients, 698 met the inclusion criteria, were randomized, and received treatment with either cilostazol 100 mg P0 twice a day, pentoxifylline 400 mg PO 3 times a day, or placebo. Treatment was double-dummy to ensure study blindness. Efficacy was primarily established by maximal walking distance (MWD), measured with constant-speed, variable-grade treadmill testing, assessed at baseline and at 4, 8, 12, 16, 20, and 24 weeks. Mean MWD of cilostazol-treated patients (n=227) was significantly improved at every visit compared with patients who received pentoxifylline (n=232) or placebo (n=239). After 24 weeks of cilostazol, mean MWD increased 53.9% (107.3 m) from baseline, and the effect had not plateaued. This was better (P < 0.001) than the 30.4% (64.4 m) MWD improvement with pentoxifylline. MWD improvement with pentoxifylline was similar (P = 0.82) to that of placebo (64.7 m). Deaths and serious adverse event rates were similar in each group. Common side effects included headache (27.8% with cilostazol, 11.2% with pentoxifylline, 11.7% with placebo), palpitations (17.2% with cilostazol, 2.2% with pentoxifylllne, 1.3% with placebo), and abnormal stools. Cilostazol was significantly better than pentoxifylline or placebo for increasing walking distances; pentoxifylline was no better than placebo.

  17. Analysis of isokinetic muscle function and postural control in individuals with intermittent claudication

    PubMed Central

    Lanzarin, Morgan; Parizoto, Patricia; Santos, Gilmar M.

    2016-01-01

    BACKGROUND: Intermittent claudication (IC) is a debilitating condition that mostly affects elderly people. IC is manifested by a decrease in ambulatory function. Individuals with IC present with motor and sensory nerve dysfunction in the lower extremities, which may lead to deficits in balance. OBJECTIVE: This study aimed to measure postural control and isokinetic muscle function in individuals with intermittent claudication. METHOD: The study included 32 participants of both genders, 16 IC participants (mean age: 64 years, SD=6) and 16 healthy controls (mean age: 67 years, SD=5), which were allocated into two groups: intermittent claudication group (ICG) and control group (CG). Postural control was assessed using the displacement and velocity of the center of pressure (COP) during the sensory organization test (SOT) and the motor control test (MCT). Muscle function of the flexor and extensor muscles of the knee and ankle was measured by an isokinetic dynamometer. Independent t tests were used to calculate the between-group differences. RESULTS: The ICG presented greater displacement (p =0.027) and speed (p =0.033) of the COP in the anteroposterior direction (COPap) during the MCT, as well as longer latency (p =0.004). There were no between-group differences during the SOT. The ICG showed decreased muscle strength and power in the plantar flexors compared to the CG. CONCLUSION: Subjects with IC have lower values of strength and muscle power of plantiflexores, as well as changes in postural control in dynamic conditions. These individuals may be more vulnerable to falls than healthy subjects. PMID:26786077

  18. Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication

    PubMed Central

    Werncke, Thomas; Steffen, Ingo G.; Hamm, Bernd; Elgeti, Thomas

    2016-01-01

    Aim To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD? Material and Methods Retrospective re-evaluation of CTAs performed in patients with acute or chronic intermittent claudication (i.e., Fontaine stages I to IIB) between January 2005 and October 2013. Allocation to one of three categories of underlying causes of IC symptoms: vascular, musculoskeletal (MSK) or both. Clinically relevant extravascular incidental findings were evaluated. Medical records were reviewed to verify specific therapies as well as main and incidental findings. Results While focused on vascular imaging, CTA image quality was sufficient for evaluation of the MSK system in all cases. The underlying cause of IC was diagnosed in run-off CTA as vascular, MSK and a combination in n = 138 (65%), n = 10 (4%), and n = 66 (31%) cases, respectively. Specific vascular or MSK therapy was recorded in n = 123 and n = 9 cases. In n = 82, no follow-up was possible. Clinically relevant extravascular incidental findings were detected in n = 65 patients (30%) with neoplasia, ascites and pleural effusion being the most common findings. Discussion Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment. PMID:27054846

  19. Asymptomatic Peripheral Arterial Disease Is Associated With More Adverse Lower Extremity Characteristics Than Intermittent Claudication

    PubMed Central

    McDermott, Mary M.; Guralnik, Jack M.; Ferrucci, Luigi; Tian, Lu; Liu, Kiang; Liao, Yihua; Green, David; Sufit, Robert; Hoff, Frederick; Nishida, Takashi; Sharma, Leena; Pearce, William H.; Schneider, Joseph R.; Criqui, Michael H.

    2016-01-01

    Background This study assessed functional performance, calf muscle characteristics, peripheral nerve function, and quality of life in asymptomatic persons with peripheral arterial disease (PAD). Methods and Results PAD participants (n=465) had an ankle brachial index <0.90. Non-PAD participants (n=292) had an ankle brachial index of 0.90 to 1.30. PAD participants were categorized into leg symptom groups including intermittent claudication (n=215) and always asymptomatic (participants who never experienced exertional leg pain, even during the 6-minute walk; n=72). Calf muscle was measured with computed tomography. Analyses were adjusted for age, sex, race, ankle brachial index, comorbidities, and other confounders. Compared with participants with intermittent claudication, always asymptomatic PAD participants had smaller calf muscle area (4935 versus 5592 mm2; P<0.001), higher calf muscle percent fat (16.10% versus 9.45%; P<0.001), poorer 6-minute walk performance (966 versus 1129 ft; P=0.0002), slower usual-paced walking speed (P=0.0019), slower fast-paced walking speed (P<0.001), and a poorer Short-Form 36 Physical Functioning score (P=0.016). Compared with an age-matched, sedentary, non-PAD cohort, always asymptomatic PAD participants had smaller calf muscle area (5061 versus 5895 mm2; P=0.009), poorer 6-minute walk performance (1126 versus 1452 ft; P<0.001), and poorer Walking Impairment Questionnaire speed scores (40.87 versus 57.78; P=0.001). Conclusions Persons with PAD who never experience exertional leg symptoms have poorer functional performance, poorer quality of life, and more adverse calf muscle characteristics compared with persons with intermittent claudication and a sedentary, asymptomatic, age-matched group of non-PAD persons. PMID:18458172

  20. The case for intermittent pneumatic compression of the lower extremity as a novel treatment in arterial claudication.

    PubMed

    Delis, Konstantinos T

    2005-03-01

    Appreciation of the physiologic role of the natural muscle pumps of the lower limb in enhancing the return of venous blood promoted the development of intermittent pneumatic limb compression (IPC) systems that could activate these pumps artificially. The application of IPC to the foot (IPC(foot)), calf (IPC(calf)) or both (IPC(foot + calf)) on dependency generates a significant acute arterial leg inflow enhancement in patients with intermittent claudication that is highest with IPC(foot + calf), followed by IPC(calf) and IPC(foot). This enhancement is attributable to the leg venous pressure decrease after venous expulsion with IPC, which results in arteriovenous pressure elevation, and a marked attenuation in peripheral resistance to flow due to a transient abolition of peripheral sympathetic autoregulation and the release of nitric oxide. Implementation of IPC(foot) and IPC(foot + calf) for 3 to 5 months (> or = 2.5 hours/day) has been shown to improve the walking capacity and the ankle pressure indices of patients with intermittent claudication, with a significant beneficial impact on the quality of life. As the prevalence of symptomatic peripheral arterial disease is projected to increase substantially over the next decades with the aging population in Western societies and in the absence of established, cost-effective methods of treatment for claudication, the reported efficacy of IPC in claudication certainly warrants clinical attention. Level-1 clinical evidence by three independent investigators supports the clinical role of IPC in arterial claudication, reinforced by its domiciliary applicability, the high patient compliance with which it is associated, and the modest cost. This review offers an insight into the hemodynamic and clinical effects of IPC in patients with claudication in relation to the physiologic mechanisms proposed in explanation of these effects. PMID:15952694

  1. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  2. High-intensity interval training for intermittent claudication in a vascular rehabilitation program.

    PubMed

    Adams, Jenny; Ogola, Gerald; Stafford, Pamala; Koutras, Phoebus; Hartman, Julie

    2006-06-01

    This article reports an observational study investigating the safety and effectiveness of a high-intensity interval exercise program for patients with peripheral arterial disease. Patients were asked to walk on a treadmill to maximal claudication pain six times in each exercise session, with 3-minute rests in between. Once a patient could walk continuously for 6 minutes without reaching maximal pain, speed and/or grade was increased. To account for the changes in speed and grade, patients' walking ability was measured as a rehabilitation score, calculated as the product of the two. A total of 47 patients were included in the study. Results showed overall improvement in the rehabilitation score with participation in the program, and specifically showed that participation in more exercise sessions led to greater improvement. Moreover, no adverse events occurred in the study patients, suggesting patients with peripheral arterial disease can safely tolerate high-intensity exercise programs.

  3. Frequency-domain analysis of absolute gravimeters

    NASA Astrophysics Data System (ADS)

    Svitlov, S.

    2012-12-01

    An absolute gravimeter is analysed as a linear time-invariant system in the frequency domain. Frequency responses of absolute gravimeters are derived analytically based on the propagation of the complex exponential signal through their linear measurement functions. Depending on the model of motion and the number of time-distance coordinates, an absolute gravimeter is considered as a second-order (three-level scheme) or third-order (multiple-level scheme) low-pass filter. It is shown that the behaviour of an atom absolute gravimeter in the frequency domain corresponds to that of the three-level corner-cube absolute gravimeter. Theoretical results are applied for evaluation of random and systematic measurement errors and optimization of an experiment. The developed theory agrees with known results of an absolute gravimeter analysis in the time and frequency domains and can be used for measurement uncertainty analyses, building of vibration-isolation systems and synthesis of digital filtering algorithms.

  4. Risk Factor Analysis for Buttock Claudication after Internal Iliac Artery Embolization with Endovascular Aortic Aneurysm Repair

    PubMed Central

    Choi, Hye Ryeon; Park, Ki Hyuk; Lee, Jae Hoon

    2016-01-01

    Purpose: Endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) involving the common iliac artery requires extension of the stent-graft limb into the external iliac artery. For this procedure, internal iliac artery (IIA) embolization is performed to prevent type II endoleak. In this study, we investigated the frequency and risk factor of buttock claudication (BC) in patients having interventional embolization of the IIA. Materials and Methods: From January 2010 to December 2013, a total of 110 patients with AAA were treated with EVAR in our institution. This study included 27 patients (24.5%) who had undergone unilateral IIA coil embolization with EVAR. We examined hospital charts retrospectively and interviewed by telephone for the occurrence of BC. Results: Mean age of total patients was 71.9±7.0 years and 88.9% were males. During a mean follow-up of 8.65±9.04 months, the incidence of BC was 40.7% (11 of 27 patients). In 8 patients with claudication, the symptoms had resolved within 1 month of IIA embolization, but the symptoms persisted for more than 6 months in the remaining 3 patients. In univariate and multivariate analysis, risk factors such as age, sex, comorbidity, patency of collateral arteries, and anatomical characteristics of AAA were not significantly related with BC. Conclusion: In this study, BC was a frequent complication of IIA embolization during EVAR and there was no associated risk factor. Certain principles such as checking preoperative angiogram, proximal and unilateral IIA embolization may have contributed to reducing the incidence of BC. PMID:27386451

  5. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  6. Reliability of the vascular claudication reporting in diabetic patients with peripheral arterial disease: a study with near-infrared spectroscopy.

    PubMed

    Manfredini, Fabio; Lamberti, Nicola; Malagoni, Anna Maria; Zambon, Christel; Basaglia, Nino; Mascoli, Francesco; Manfredini, Roberto; Zamboni, Paolo

    2015-04-01

    We evaluated whether altered reporting of ischemic symptoms occurs in diabetic patients with peripheral arterial disease (PAD) and stable claudication. Patients (n = 152) with claudication were enrolled (120 males; mean age: 71.0 ± 8.6 years): 74 with diabetes (DM-PAD) and 78 without (DMfree-PAD). The degree of muscle oxygenation at symptom onset and maximal speed (Smax) during an incremental treadmill test was recorded at the gastrocnemius by near-infrared spectroscopy (NIRS) and quantified by area under the curve of oxygenated hemoglobin (AUC-Hbo 2) and area under the curve of differential hemoglobin (AUC-dHb). The DM-PAD and DMfree-PAD showed similar exercise capacities inversely correlated with the degree of muscle oxygenation but significantly lower values of AUC-Hbo 2 and AUC-dHb for DM-PAD at symptom onset and Smax (-356 vs -122 and -1200 vs -359, P < .0001). During a NIRS-assisted test, the report of claudication in the presence of diabetes was delayed, occurring at a lower degree of oxygenation than in patients with PAD only, with potential implications for testing, functional staging, and balance disorders.

  7. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  8. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  9. Influence of regular exercise on body fat and eating patterns of patients with intermittent claudication.

    PubMed

    Leicht, Anthony; Crowther, Robert; Golledge, Jonathan

    2015-05-18

    This study examined the impact of regular supervised exercise on body fat, assessed via anthropometry, and eating patterns of peripheral arterial disease patients with intermittent claudication (IC). Body fat, eating patterns and walking ability were assessed in 11 healthy adults (Control) and age- and mass-matched IC patients undertaking usual care (n = 10; IC-Con) or supervised exercise (12-months; n = 10; IC-Ex). At entry, all groups exhibited similar body fat and eating patterns. Maximal walking ability was greatest for Control participants and similar for IC-Ex and IC-Con patients. Supervised exercise resulted in significantly greater improvements in maximal walking ability (IC-Ex 148%-170% vs. IC-Con 29%-52%) and smaller increases in body fat (IC-Ex -2.1%-1.4% vs. IC-Con 8.4%-10%). IC-Con patients exhibited significantly greater increases in body fat compared with Control at follow-up (8.4%-10% vs. -0.6%-1.4%). Eating patterns were similar for all groups at follow-up. The current study demonstrated that regular, supervised exercise significantly improved maximal walking ability and minimised increase in body fat amongst IC patients without changes in eating patterns. The study supports the use of supervised exercise to minimize cardiovascular risk amongst IC patients. Further studies are needed to examine the additional value of other lifestyle interventions such as diet modification.

  10. Influence of Regular Exercise on Body Fat and Eating Patterns of Patients with Intermittent Claudication

    PubMed Central

    Leicht, Anthony; Crowther, Robert; Golledge, Jonathan

    2015-01-01

    This study examined the impact of regular supervised exercise on body fat, assessed via anthropometry, and eating patterns of peripheral arterial disease patients with intermittent claudication (IC). Body fat, eating patterns and walking ability were assessed in 11 healthy adults (Control) and age- and mass-matched IC patients undertaking usual care (n = 10; IC-Con) or supervised exercise (12-months; n = 10; IC-Ex). At entry, all groups exhibited similar body fat and eating patterns. Maximal walking ability was greatest for Control participants and similar for IC-Ex and IC-Con patients. Supervised exercise resulted in significantly greater improvements in maximal walking ability (IC-Ex 148%–170% vs. IC-Con 29%–52%) and smaller increases in body fat (IC-Ex −2.1%–1.4% vs. IC-Con 8.4%–10%). IC-Con patients exhibited significantly greater increases in body fat compared with Control at follow-up (8.4%–10% vs. −0.6%–1.4%). Eating patterns were similar for all groups at follow-up. The current study demonstrated that regular, supervised exercise significantly improved maximal walking ability and minimised increase in body fat amongst IC patients without changes in eating patterns. The study supports the use of supervised exercise to minimize cardiovascular risk amongst IC patients. Further studies are needed to examine the additional value of other lifestyle interventions such as diet modification. PMID:25993298

  11. Compared to Intermittant Claudication Critical Limb Ischemia Is Associated with Elevated Levels of Cytokines

    PubMed Central

    Maksimow, Mikael; Hollmén, Maija; Jalkanen, Sirpa; Hakovirta, Harri

    2016-01-01

    Critical limb ischemia (CLI) is the advanced stage of peripheral artery disease (PAD) and associated with an extremely poor clinical outcome. In order to understand the possible role of circulating cytokines and poor outcome associated with CLI we compared the circulating cytokine profile of patients with CLI against patients with intermittent claudication (IC). The levels of 48 circulating cytokines were examined in 226 consecutive patients with peripheral artery disease (PAD) admitted for elective, non-urgent, invasive treatment of IC or CLI. The PAD patient cohort was evenly distributed between subjects with IC (46.5%) and CLI (53.5%). As accustomed in PAD, CLI was associated with higher age, chronic kidney disease and diabetes when compared to IC (P < 0.01 for all). In multivariable linear regression modeling taking into account the baseline differences between IC and CLI groups CLI was independently associated with elevated levels of a large number of cytokines: IL-1β, IL-1ra, IL-2Rα, IL-4, IL-6, IL-10, IFN-γ, GM-CSF, G-CSF (P < 0.01 for all), and IL-2, IL-7, IL-12, IL-13, IL-17, bFGF, VEGF, SCGF-β (P < 0.05 for all). The current findings indicate that CLI is associated with a circulating cytokine profile, which resembles serious medical conditions such as severe pancreatitis, sepsis, or even cancer. Compared to IC, CLI is a systemic inflammatory condition, which may explain the extremely poor outcome associated with it. PMID:27611073

  12. Compared to Intermittant Claudication Critical Limb Ischemia Is Associated with Elevated Levels of Cytokines.

    PubMed

    Jalkanen, Juho; Maksimow, Mikael; Hollmén, Maija; Jalkanen, Sirpa; Hakovirta, Harri

    2016-01-01

    Critical limb ischemia (CLI) is the advanced stage of peripheral artery disease (PAD) and associated with an extremely poor clinical outcome. In order to understand the possible role of circulating cytokines and poor outcome associated with CLI we compared the circulating cytokine profile of patients with CLI against patients with intermittent claudication (IC). The levels of 48 circulating cytokines were examined in 226 consecutive patients with peripheral artery disease (PAD) admitted for elective, non-urgent, invasive treatment of IC or CLI. The PAD patient cohort was evenly distributed between subjects with IC (46.5%) and CLI (53.5%). As accustomed in PAD, CLI was associated with higher age, chronic kidney disease and diabetes when compared to IC (P < 0.01 for all). In multivariable linear regression modeling taking into account the baseline differences between IC and CLI groups CLI was independently associated with elevated levels of a large number of cytokines: IL-1β, IL-1ra, IL-2Rα, IL-4, IL-6, IL-10, IFN-γ, GM-CSF, G-CSF (P < 0.01 for all), and IL-2, IL-7, IL-12, IL-13, IL-17, bFGF, VEGF, SCGF-β (P < 0.05 for all). The current findings indicate that CLI is associated with a circulating cytokine profile, which resembles serious medical conditions such as severe pancreatitis, sepsis, or even cancer. Compared to IC, CLI is a systemic inflammatory condition, which may explain the extremely poor outcome associated with it. PMID:27611073

  13. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses. PMID:23586876

  14. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses.

  15. Buttock Claudication and Erectile Dysfunction After Internal Iliac Artery Embolization in Patients Prior to Endovascular Aortic Aneurysm Repair

    SciTech Connect

    Rayt, H. S. Bown, M. J.; Lambert, K. V.; Fishwick, N. G.; McCarthy, M. J.; London, N. J. M.; Sayers, R. D.

    2008-07-15

    Coil embolization of the internal iliac artery (IIA) is used to extend the application of endovascular aneurysm repair (EVAR) in cases of challenging iliac anatomy. Pelvic ischemia is a complication of the technique, but reports vary as to the rate and severity. This study reports our experience with IIA embolization and compares the results to those of other published series. The vascular unit database of the Leicester Royal Infirmary was used to identify patients who had undergone IIA coil embolization prior to EVAR. Data were collected from hospital case notes and by telephone interviews. Thirty-eight patients were identified; 29 of these were contactable by telephone. A literature search was performed for other studies of IIA embolization and the results were pooled. In this series buttock claudication occurred in 55% (16 of 29 patients) overall: in 52% of unilateral embolizations (11 of 21) and 63% of bilateral embolizations (5 of 8). New erectile dysfunction occurred in 46% (6 of 13 patients) overall: in 38% of unilateral embolizations (3 of 8) and 60% of bilateral embolizations (3 of 5). The literature review identified 18 relevant studies. The results were pooled with our results, to give 634 patients in total. Buttock claudication occurred in 28% overall (178 of 634 patients): in 31% of unilateral embolizations (99 of 322) and 35% of bilateral embolizations (34 of 98) (p = 0.46, Fisher's exact test). New erectile dysfunction occurred in 17% overall (27 of 159 patients): in 17% of unilateral embolizations (16 of 97) and 24% of bilateral embolizations (9 of 38) (p = 0.33). We conclude that buttock claudication and erectile dysfunction are frequent complications of IIA embolization and patients should be counseled accordingly.

  16. Contemporary medical management of peripheral arterial disease: a focus on risk reduction and symptom relief for intermittent claudication.

    PubMed

    Agrawal, Kush; Eberhardt, Robert T

    2015-02-01

    Peripheral arterial disease (PAD) is primarily caused by progressive systemic atherosclerosis manifesting in the lower extremities. This review addresses the epidemiology, clinical presentation and evaluation, and medical management of PAD, with a focus on intermittent claudication. Key advances in the recognition of cardiovascular risk in asymptomatic individuals with mildly abnormal ankle-brachial index, newer reflections on exercise therapy, and a review of established and investigational agents for the treatment of symptomatic PAD, such as cilostazol, statins, and angiotensin-converting enzyme inhibitors, are highlighted.

  17. [Interpretation and consideration of the Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities management of asymptomatic disease and claudication].

    PubMed

    Shen, Chenyang; Li, Weihao

    2016-02-01

    Atherosclerotic occlusive disease of the lower extremities (ASO-LE) has the third highest rate among systematic atherosclerosis obliterans, ranking after coronary heart disease and stoke, and the disease burden of ASO-LE has been continuously increasing. Invasive revascularizations, which is presented by endovascular therapy technique, has undergone a dramatic development in the past couples of decades. However, controversy concerned about the surgical management and operative indications has heated up in the meanwhile. Thus Society for Vascular Surgery (SVS) published the practice guidelines for ASO-LE with asymptomatic disease and claudication in March, 2015. At the first time the guideline definitely opposed the aggressive invasive revascularization for ASO-LE patients with asymptomatic disease or claudication under satisfied tolerance. Instead, it posed the extreme emphasis on the pharmacotherapy with risk reduction of atherosclerosis at the core and the exercise therapy with supervised or home-based exercise program at the core for ASO-LE patients with asymptomatic disease and claudication.

  18. Psychometric Assessment of the Japanese Version of the Zurich Claudication Questionnaire (ZCQ): Reliability and Validity

    PubMed Central

    Hara, Nobuhiro; Matsudaira, Ko; Masuda, Kazuhiro; Tohnosu, Juichi; Takeshita, Katsushi; Kobayashi, Atsuki; Murakami, Motoaki; Kawamura, Naohiro; Yamakawa, Kiyohumi; Terayama, Sei; Ogihara, Satoshi; Shiono, Hiroo; Morii, Jiro; Hayakawa, Keiji; Kato, So; Nakamura, Kozo; Oka, Hiroyuki; Sawada, Takayuki; Inuzuka, Kyoko; Kikuchi, Norimasa

    2016-01-01

    Purpose The Zurich Claudication Questionnaire (ZCQ) is a self-administered measure to evaluate symptom severity, physical function, and surgery satisfaction in lumbar spinal stenosis (LSS). The purpose of this study is to assess the psychometric properties of the Japanese ZCQ in LSS patients. Methods LSS patients who are scheduled to undergo surgery were recruited from 12 facilities. Responses to several questionnaires, including the Japanese ZCQ; the visual analogue scale (VAS) to evaluate the degree of pain in the buttocks/legs, numbness in the buttocks/legs, and low back pain; the Oswestry Disability Index (ODI); and the SF-36v2, were collected before surgery and again 3 months after surgery (the post-surgery ZCQ was administered twice for test-retest reliability). For reliability, test-retest reliability was evaluated using the intra-class coefficient (ICC) and internal consistency was evaluated using Cronbach’s alpha coefficient. Concurrent validity was assessed using Spearman’s correlation coefficients between the Japanese ZCQ and other questionnaires. Effect size (ES) and standard response mean were calculated for responsiveness. All analyses were performed individually for the Japanese ZCQ symptom, function, and satisfaction domains. Results Data from 180 LSS patients were used in this analysis. The ICCs were 0.81, 0.89, and 0.88 and Cronbach’s alpha coefficients were 0.78, 0.84, and 0.92 for the Japanese ZCQ symptom, function, and satisfaction domains, respectively. Regarding the concurrent validity, strong correlations (±0.5) were demonstrated between the Japanese ZCQ domains and the VAS leg pain, ODI, and SF-36v2 physical functioning or bodily pain, whereas correlations were approximately 0.3 in scales measuring other symptoms that are less related to symptom, function, or satisfaction domains. ESs showed high values for the ZCQ symptom and function domains (-1.73 for both). Conclusions These psychometric assessments demonstrate that the Japanese

  19. The absolute path command

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the absolute path to a relative directory from the current working directory.« less

  20. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  1. Cramps and muscular pain: prevention with pycnogenol in normal subjects, venous patients, athletes, claudicants and in diabetic microangiopathy.

    PubMed

    Vinciguerra, G; Belcaro, G; Cesarone, M R; Rohdewald, P; Stuard, S; Ricci, A; Di Renzo, A; Hosoi, M; Dugall, M; Ledda, A; Cacchio, M; Acerbi, G; Fano, F

    2006-01-01

    The aim of this study was to assess the preventive action of Pycnogenol (Horphag Research Ltd, UK) on cramps and muscular pain in different groups of subjects and patients. The study included a 5-week observation period (4 weeks treatment and one follow-up week after the suspension of treatment) to evaluate the efficacy of Pycnogenol after its withdrawal. Four 50 mg capsules (total dose 200 mg/day) were prescribed with suggestion to drink at least 1.5 liters of water every day. In the first part of the study 66 healthy subjects completed a 5-week follow-up period. The difference between number of cramps attacks recorded within the 2 weeks before inclusion and the number of episodes during the fourth (p <0.05) and fifth (p <0.05) week were statistically significant. In normal subjects the average number of episodes was reduced from 4.8 (1.2) events per week to 1.3 (1.1) at 4 weeks (p <0.05). In venous patients the decrease in events was from 6.3 (1.1) to 2.6 (0.4) per week (p <0.05). In athletes the number of episodes decreased from 8.6 (2) to 2.4 (0.5) (p <0.05). The decrease was still present at 5 weeks in the 3 groups, to levels significantly lower than inclusion values (p <0.05). In the second part of the study, patients with intermittent claudication and diabetic microangiopathy were evaluated and treated (4 weeks). The groups treated with Pycnogenol and the control, placebo groups were comparable. There was a significant decrease in the number of cramps episodes (p <0.05) and in the score concerning muscular pain (p <0.05) in claudicants and diabetics. No significant effects were observed in the placebo groups. In conclusion, cramps and muscular pain, common in these 2 types of patients, were decreased by the use of Pycnogenol. Globally, these results suggest that the use of Pycnogenol prevents cramps, muscular pain at rest, and pain after/during exercise in normals, in athletes prone to cramps, in patients with venous disease, in claudicants, and in diabetics

  2. The absolute disparity anomaly and the mechanism of relative disparities.

    PubMed

    Chopin, Adrien; Levi, Dennis; Knill, David; Bavelier, Daphne

    2016-06-01

    There has been a long-standing debate about the mechanisms underlying the perception of stereoscopic depth and the computation of the relative disparities that it relies on. Relative disparities between visual objects could be computed in two ways: (a) using the difference in the object's absolute disparities (Hypothesis 1) or (b) using relative disparities based on the differences in the monocular separations between objects (Hypothesis 2). To differentiate between these hypotheses, we measured stereoscopic discrimination thresholds for lines with different absolute and relative disparities. Participants were asked to judge the depth of two lines presented at the same distance from the fixation plane (absolute disparity) or the depth between two lines presented at different distances (relative disparity). We used a single stimulus method involving a unique memory component for both conditions, and no extraneous references were available. We also measured vergence noise using Nonius lines. Stereo thresholds were substantially worse for absolute disparities than for relative disparities, and the difference could not be explained by vergence noise. We attribute this difference to an absence of conscious readout of absolute disparities, termed the absolute disparity anomaly. We further show that the pattern of correlations between vergence noise and absolute and relative disparity acuities can be explained jointly by the existence of the absolute disparity anomaly and by the assumption that relative disparity information is computed from absolute disparities (Hypothesis 1).

  3. The absolute disparity anomaly and the mechanism of relative disparities

    PubMed Central

    Chopin, Adrien; Levi, Dennis; Knill, David; Bavelier, Daphne

    2016-01-01

    There has been a long-standing debate about the mechanisms underlying the perception of stereoscopic depth and the computation of the relative disparities that it relies on. Relative disparities between visual objects could be computed in two ways: (a) using the difference in the object's absolute disparities (Hypothesis 1) or (b) using relative disparities based on the differences in the monocular separations between objects (Hypothesis 2). To differentiate between these hypotheses, we measured stereoscopic discrimination thresholds for lines with different absolute and relative disparities. Participants were asked to judge the depth of two lines presented at the same distance from the fixation plane (absolute disparity) or the depth between two lines presented at different distances (relative disparity). We used a single stimulus method involving a unique memory component for both conditions, and no extraneous references were available. We also measured vergence noise using Nonius lines. Stereo thresholds were substantially worse for absolute disparities than for relative disparities, and the difference could not be explained by vergence noise. We attribute this difference to an absence of conscious readout of absolute disparities, termed the absolute disparity anomaly. We further show that the pattern of correlations between vergence noise and absolute and relative disparity acuities can be explained jointly by the existence of the absolute disparity anomaly and by the assumption that relative disparity information is computed from absolute disparities (Hypothesis 1). PMID:27248566

  4. Intermittent claudication-like syndrome secondary to atherosclerosis in a yellow-naped Amazon parrot (Amazona ochrocephala auropalliata).

    PubMed

    Beaufrère, Hugues; Holder, Kali A; Bauer, Rudy; Schnellbacher, Rodney; Pariaut, Romain; Tully, Thomas N; Wakamatsu, Nobuko

    2011-12-01

    A 25-year-old yellow-naped Amazon parrot (Amazona ochrocephala auropalliata) was presented for nasal discharge and sneezing. Physical examination revealed poor feather quality, a mild serous nasal discharge, and a mass on the dorsal surface of the oral cavity. Cytologic examination of a mass aspirate as well as results of a choanal culture revealed squamous metaplasia of the salivary glands and bacterial rhinitis, respectively. Following resolution of the presenting conditions, the patient was presented for hind limb weakness and ataxia. The clinical signs were transient and generally resolved with rest but could be reproduced after stressful episodes, such as restraint for procedures or treatment. Test results from a complete blood count, biochemistry profile, whole-body radiographs, needle electromyography of the leg muscles, and an edrophonium challenge test were within reference limits. Based on the clinical signs and results of the diagnostic workup, the presumptive diagnosis was intermittent claudication, a condition caused by peripheral vascular disease and defined as intermittent weakness and pain in the legs induced by exercise and relieved by rest. Shortly after initiation of treatment with isoxsuprine, the bird died. Postmortem examination and histopathology revealed severe atherosclerotic lesions throughout the vascular system with stenotic lesions present in the abdominal aorta and femoral arteries. Electron microscopic examination of the great arteries was also performed and helped to further characterize the nature of the lesions. This case is the first report, to our knowledge, of an intermittent claudication-like syndrome associated with peripheral atherosclerosis in a psittacine bird. In addition, the distribution and some of the macroscopic and histopathologic features of the lesions differ from previous descriptions of atherosclerosis in psittacine birds.

  5. MSTAR: an absolute metrology sensor with sub-micron accuracy for space-based applications

    NASA Technical Reports Server (NTRS)

    Peters, Robert D.; Lay, Oliver P.; Dubovitsky, Serge; Burger, Johan P.; Jeganathan, Muthu

    2004-01-01

    The MSTAR sensor is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with subnanometer accuracy.

  6. ABSOLUTE POLARIMETRY AT RHIC.

    SciTech Connect

    OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.

    2007-09-10

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

  7. Combined Use of Absolute and Differential Seismic Arrival Time Data to Improve Absolute Event Location

    NASA Astrophysics Data System (ADS)

    Myers, S.; Johannesson, G.

    2012-12-01

    Arrival time measurements based on waveform cross correlation are becoming more common as advanced signal processing methods are applied to seismic data archives and real-time data streams. Waveform correlation can precisely measure the time difference between the arrival of two phases, and differential time data can be used to constrain relative location of events. Absolute locations are needed for many applications, which generally requires the use of absolute time data. Current methods for measuring absolute time data are approximately two orders of magnitude less precise than differential time measurements. To exploit the strengths of both absolute and differential time data, we extend our multiple-event location method Bayesloc, which previously used absolute time data only, to include the use of differential time measurements that are based on waveform cross correlation. Fundamentally, Bayesloc is a formulation of the joint probability over all parameters comprising the multiple event location system. The Markov-Chain Monte Carlo method is used to sample from the joint probability distribution given arrival data sets. The differential time component of Bayesloc includes scaling a stochastic estimate of differential time measurement precision based the waveform correlation coefficient for each datum. For a regional-distance synthetic data set with absolute and differential time measurement error of 0.25 seconds and 0.01 second, respectively, epicenter location accuracy is improved from and average of 1.05 km when solely absolute time data are used to 0.28 km when absolute and differential time data are used jointly (73% improvement). The improvement in absolute location accuracy is the result of conditionally limiting absolute location probability regions based on the precise relative position with respect to neighboring events. Bayesloc estimates of data precision are found to be accurate for the synthetic test, with absolute and differential time measurement

  8. Simulation Distances

    NASA Astrophysics Data System (ADS)

    Černý, Pavol; Henzinger, Thomas A.; Radhakrishna, Arjun

    Boolean notions of correctness are formalized by preorders on systems. Quantitative measures of correctness can be formalized by real-valued distance functions between systems, where the distance between implementation and specification provides a measure of "fit" or "desirability." We extend the simulation preorder to the quantitative setting, by making each player of a simulation game pay a certain price for her choices. We use the resulting games with quantitative objectives to define three different simulation distances. The correctness distance measures how much the specification must be changed in order to be satisfied by the implementation. The coverage distance measures how much the implementation restricts the degrees of freedom offered by the specification. The robustness distance measures how much a system can deviate from the implementation description without violating the specification. We consider these distances for safety as well as liveness specifications. The distances can be computed in polynomial time for safety specifications, and for liveness specifications given by weak fairness constraints. We show that the distance functions satisfy the triangle inequality, that the distance between two systems does not increase under parallel composition with a third system, and that the distance between two systems can be bounded from above and below by distances between abstractions of the two systems. These properties suggest that our simulation distances provide an appropriate basis for a quantitative theory of discrete systems. We also demonstrate how the robustness distance can be used to measure how many transmission errors are tolerated by error correcting codes.

  9. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  10. Measurement of absolute gravity acceleration in Firenze

    NASA Astrophysics Data System (ADS)

    de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

    2011-01-01

    This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0) μGal and (980 492 048.3 ± 3.0) μGal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

  11. Distance Education.

    ERIC Educational Resources Information Center

    ASPBAE Courier, 1984

    1984-01-01

    This publication is devoted to distance education. "The Future of Distance Teaching Universities in a Worldwide Perspectives" (John S. Daniel) examines challenges likely to face the various countries and regions of the world in the next decade. "An Australian University's Approach to Distance Education--Formal and Non-Formal" (Peter M. Grayson)…

  12. Asteroid absolute magnitudes and slope parameters

    NASA Technical Reports Server (NTRS)

    Tedesco, Edward F.

    1991-01-01

    A new listing of absolute magnitudes (H) and slope parameters (G) has been created and published in the Minor Planet Circulars; this same listing will appear in the 1992 Ephemerides of Minor Planets. Unlike previous listings, the values of the current list were derived from fits of data at the V band. All observations were reduced in the same fashion using, where appropriate, a single basis default value of 0.15 for the slope parameter. Distances and phase angles were computed for each observation. The data for 113 asteroids was of sufficiently high quality to permit derivation of their H and G. These improved absolute magnitudes and slope parameters will be used to deduce the most reliable bias-corrected asteroid size-frequency distribution yet made.

  13. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  14. Absolute method of measuring magnetic susceptibility

    USGS Publications Warehouse

    Thorpe, A.; Senftle, F.E.

    1959-01-01

    An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

  15. Over-Expression of PUMA Correlates with the Apoptosis of Spinal Cord Cells in Rat Neuropathic Intermittent Claudication Model

    PubMed Central

    Ma, Bin; Shi, Jiangang; Jia, Lianshun; Yuan, Wen; Wu, Jianfeng; Fu, Zhiyi; Wang, Yuan; Liu, Ning; Guan, Zhengmao

    2013-01-01

    Background Neuropathic intermittent claudication (NIC) is a typical clinical symptom of lumbar spinal stenosis and the apoptosis of neurons caused by cauda equina compression (CEC) has been proposed as an important reason. Whereas, the factors and the mechanism involved in the process of apoptosis induced by CEC remain unclear. Methodology and Results In our modified rat model of NIC, a trapezoid-shaped silicon rubber was inserted into the epidural space under the L5 and L6 vertebral plate. Obvious apoptosis was observed in spinal cord cells after compression by TUNEL assay. Simultaneously, qRT-PCR and immunohistochemistry showed that the expression levels of PUMA (p53 up-regulated modulator of apoptosis) and p53 were upregulated significantly in spinal cord under compression, while the expression of p53 inhibitor MDM2 and SirT2 decreased in the same region. Furthermore, CEC also resulted in the upregulation of Bcl-2 pro-apoptotic genes expression and caspase-3 activation. With the protection of Methylprednisolone, the upregulation of PUMA and p53 expression as well as the decrease of MDM2 and SirT2 in spinal cord were partially rescued in western bolt analysis. Conclusions These results suggest that over-expression of PUMA correlates with CEC caused apoptosis of spinal cord cells, which is characterized by the increase of p53, Bax and Bad expression. PUMA upregulation might be crucial to induce apoptosis of spinal cord cells through p53-dependent pathway in CEC. PMID:23658678

  16. Micron Accurate Absolute Ranging System: Range Extension

    NASA Technical Reports Server (NTRS)

    Smalley, Larry L.; Smith, Kely L.

    1999-01-01

    The purpose of this research is to investigate Fresnel diffraction as a means of obtaining absolute distance measurements with micron or greater accuracy. It is believed that such a system would prove useful to the Next Generation Space Telescope (NGST) as a non-intrusive, non-contact measuring system for use with secondary concentrator station-keeping systems. The present research attempts to validate past experiments and develop ways to apply the phenomena of Fresnel diffraction to micron accurate measurement. This report discusses past research on the phenomena, and the basis of the use Fresnel diffraction distance metrology. The apparatus used in the recent investigations, experimental procedures used, preliminary results are discussed in detail. Continued research and equipment requirements on the extension of the effective range of the Fresnel diffraction systems is also described.

  17. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  18. Be Resolute about Absolute Value

    ERIC Educational Resources Information Center

    Kidd, Margaret L.

    2007-01-01

    This article explores how conceptualization of absolute value can start long before it is introduced. The manner in which absolute value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…

  19. Intermittent claudication in an athlete--popliteal artery entrapment: a case report.

    PubMed

    Taunton, J E; Maxwell, T M

    1982-09-01

    This case study reports a 26 year old female athlete who presented with a history of cramp-like right calf pain. She was limited to a walking distance of only three blocks. She had been referred to the Sports Medicine Clinic with a diagnosis of "shin splints". On examination of the pedal pulses it was found that the right posterior tibial pulse was absent. A diagnosis of popliteal artery entrapment was made which was confirmed by Doppler studies following treadmill walking and femoral arteriograms. Surgery was performed which included resection of the entrapped artery by the plantaris tendon and endarterectomy, plus patch graft angioplasty. The artery had been completely occluded. The patient resumed full activity pain free. This case report emphasizes that all leg pains in athletes are not variants of "shin splints". Popliteal artery entrapment is an uncommon condition that requires early detection. A detailed history and thorough examination of the peripheral pulses is essential to prevent long term sequelae of arterial deficiency.

  20. Optimization, ex vivo permeation, and stability study of lipid nanocarrier loaded gelatin capsules for treatment of intermittent claudication

    PubMed Central

    Sallam, Marwa Ahmed; Marín Boscá, María Teresa

    2015-01-01

    In this study, an optimized nanodispersible oral dosage form (containing a lactate ester) was developed for cilostazol (CZL). CZL is a phosphodiesterase inhibitor used for intermittent claudication. We aimed to improve the dissolution rate and absorption of CZL giving it a better chance of oral bioavailability, and to evaluate its stability on storage. Suitable compositions of nanoemulsion preconcentrate formulations were screened via solubility and compatibility tests. Response surface methodology and a desirability approach were applied to optimize preconcentrates containing minimum amount of surfactant mixture, maximum amount of lipid, and possessing the smallest globule size, with the highest emulsification and dissolution rates and minimum risk of drug precipitation. As part of the optimization process, the main effect, interaction effects and quadratic effects of amounts of lipid, and surfactant/co-surfactant ratio on % transmittance, globule size, emulsification time, drug precipitation, and drug release were investigated. The optimized formulation consisting of 28.9% butyl lactate, 28.9% Capryol®, 27.82% Solubilisant Gamma® 2429, and 14.18% Transcutol® possessing a globule size of 60 nm was mixed with Aerosil® 200. This gave uniform free flowing granules, which were characterized for surface and powder properties. The self-nanoemulsifying granules (SNEGs) filled into hard gelatin capsules showed two- and threefold increase in CZL released compared with conventional tablet and pure drug, respectively. The amount of drug permeated using non-everted sac technique from the SNEGs was twofold higher than that permeated from the tablet suspension. The shelf life was 526 days at 25°C. Our study illustrated that the developed SNEGs, with bioenhancing ingredients, held great potential as a superior alternative to traditional oral formulations of CZL. PMID:26203244

  1. Singular perturbation of absolute stability.

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.

    1972-01-01

    It was previously shown (author, 1969) that the regions of absolute stability in the parameter space can be determined when the parameters appear on the right-hand side of the system equations, i.e., the regular case. Here, the effect on absolute stability of a small parameter attached to higher derivatives in the equations (the singular case) is studied. The Lur'e-Postnikov class of nonlinear systems is considered.

  2. Absolute flux scale for radioastronomy

    SciTech Connect

    Ivanov, V.P.; Stankevich, K.S.

    1986-07-01

    The authors propose and provide support for a new absolute flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on absolute measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of absolute scales in radio astronomy are summarized.

  3. In-flight absolute radiometric calibration of the thematic mapper

    NASA Technical Reports Server (NTRS)

    Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, R. D.; Savage, R. K.

    1983-01-01

    The TM multispectral scanner system was calibrated in an absolute manner before launch. To determine the temporal changes of the absolute radiometric calibration of the entire system, spectroradiometric measurements of the ground and the atmosphere were made simultaneously with TM collections over White Sands, New Mexico. By entering the measured values in an atmospheric radiative transfer program, the radiance levels of the in four of the spectral bands of the TM were determined. Tables show values for the reflectance of snow at White Sands measured by a modular 8 channel radiometer, and values for exoatmospheric irradiance within the TM passbands, calculated for the Earth-Sun distance using a solar radiometer.

  4. Absolute Proper Motions of Southern Globular Clusters

    NASA Astrophysics Data System (ADS)

    Dinescu, D. I.; Girard, T. M.; van Altena, W. F.

    1996-05-01

    Our program involves the determination of absolute proper motions with respect to galaxies for a sample of globular clusters situated in the southern sky. The plates cover a 6(deg) x 6(deg) area and are taken with the 51-cm double astrograph at Cesco Observatory in El Leoncito, Argentina. We have developed special methods to deal with the modelling error of the plate transformation and we correct for magnitude equation using the cluster stars. This careful astrometric treatment leads to accuracies of from 0.5 to 1.0 mas/yr for the absolute proper motion of each cluster, depending primarily on the number of measurable cluster stars which in turn is related to the cluster's distance. Space velocities are then derived which, in association with metallicities, provide key information for the formation scenario of the Galaxy, i.e. accretion and/or dissipational collapse. Here we present results for NGC 1851, NGC 6752, NGC 6584, NGC 6362 and NGC 288.

  5. Relativistic Absolutism in Moral Education.

    ERIC Educational Resources Information Center

    Vogt, W. Paul

    1982-01-01

    Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess absolute rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)

  6. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

  7. Hierarchical traits distances explain grassland Fabaceae species' ecological niches distances

    PubMed Central

    Fort, Florian; Jouany, Claire; Cruz, Pablo

    2015-01-01

    Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e., ecological niches. We measured a wide range of functional traits (root traits, leaf traits, and whole plant traits) in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species' ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems) are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems) are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance. PMID:25741353

  8. Novae as distance indicators

    NASA Technical Reports Server (NTRS)

    Ford, Holland C.; Ciardullo, Robin

    1988-01-01

    Nova shells are characteristically prolate with equatorial bands and polar caps. Failure to account for the geometry can lead to large errors in expansion parallaxes for individual novae. When simple prescriptions are used for deriving expansion parallaxes from an ensemble of randomly oriented prolate spheroids, the average distance will be too small by factors of 10 to 15 percent. The absolute magnitudes of the novae will be underestimated and the resulting distance scale will be too small by the same factors. If observations of partially resolved nova shells select for large inclinations, the systematic error in the resulting distance scale could easily be 20 to 30 percent. Extinction by dust in the bulge of M31 may broaden and shift the intrinsic distribution of maximum nova magnitudes versus decay rates. We investigated this possibility by projecting Arp's and Rosino's novae onto a composite B - 6200A color map of M31's bulge. Thirty two of the 86 novae projected onto a smooth background with no underlying structure due to the presence of a dust cloud along the line of sight. The distribution of maximum magnitudes versus fade rates for these unreddened novae is indistinguishable from the distribution for the entire set of novae. It is concluded that novae suffer very little extinction from the filamentary and patchy distribution of dust seen in the bulge of M31. Time average B and H alpha nova luminosity functions are potentially powerful new ways to use novae as standard candles. Modern CCD observations and the photographic light curves of M31 novae found during the last 60 years were analyzed to show that these functions are power laws. Consequently, unless the eruption times for novae are known, the data cannot be used to obtain distances.

  9. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  10. Moral absolutism and ectopic pregnancy.

    PubMed

    Kaczor, C

    2001-02-01

    If one accepts a version of absolutism that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the absolutism mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate.

  11. Moral absolutism and ectopic pregnancy.

    PubMed

    Kaczor, C

    2001-02-01

    If one accepts a version of absolutism that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the absolutism mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate. PMID:11262641

  12. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

  13. Classification images predict absolute efficiency.

    PubMed

    Murray, Richard F; Bennett, Patrick J; Sekuler, Allison B

    2005-02-24

    How well do classification images characterize human observers' strategies in perceptual tasks? We show mathematically that from the classification image of a noisy linear observer, it is possible to recover the observer's absolute efficiency. If we could similarly predict human observers' performance from their classification images, this would suggest that the linear model that underlies use of the classification image method is adequate over the small range of stimuli typically encountered in a classification image experiment, and that a classification image captures most important aspects of human observers' performance over this range. In a contrast discrimination task and in a shape discrimination task, we found that observers' absolute efficiencies were generally well predicted by their classification images, although consistently slightly (approximately 13%) higher than predicted. We consider whether a number of plausible nonlinearities can account for the slight under prediction, and of these we find that only a form of phase uncertainty can account for the discrepancy.

  14. Absolute calibration of optical flats

    DOEpatents

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  15. The AFGL absolute gravity program

    NASA Technical Reports Server (NTRS)

    Hammond, J. A.; Iliff, R. L.

    1978-01-01

    A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in absolute gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements.

  16. Familial Aggregation of Absolute Pitch

    PubMed Central

    Baharloo, Siamak; Service, Susan K.; Risch, Neil; Gitschier, Jane; Freimer, Nelson B.

    2000-01-01

    Absolute pitch (AP) is a behavioral trait that is defined as the ability to identify the pitch of tones in the absence of a reference pitch. AP is an ideal phenotype for investigation of gene and environment interactions in the development of complex human behaviors. Individuals who score exceptionally well on formalized auditory tests of pitch perception are designated as “AP-1.” As described in this report, auditory testing of siblings of AP-1 probands and of a control sample indicates that AP-1 aggregates in families. The implications of this finding for the mapping of loci for AP-1 predisposition are discussed. PMID:10924408

  17. Absolute V-R colors of trans-Neptunian objects

    NASA Astrophysics Data System (ADS)

    Alvarez-Candal, Alvaro; Ayala-Loera, Carmen; Ortiz, Jose-Luis; Duffard, Rene; Estela, Fernandez-Valenzuela; Santos-Sanz, Pablo

    2016-10-01

    The absolute magnitude of a minor body is the apparent magnitude that the body would have if observed from the Sun at a distance of 1AU. Absolute magnitudes are measured using phase curves, showing the change of the magnitude, normalized to unit helio and geo-centric distance, vs. phase angle. The absolute magnitude is then the Y-intercept of the curve. Absolute magnitudes are related to the total reflecting surface of the body and thus bring information of its size, coupled with the reflecting properties.Since 2011 our team has been collecting data from several telescopes spread in Europe and South America. We complemented our data with those available in the literature in order to construct phase curves of trans-Neptunian objects with at least three points. In a first release (Alvarez-Candal et al. 2016, A&A, 586, A155) we showed results for 110 trans-Neptunian objects using V magnitudes only, assuming an overall linear trend and taking into consideration rotational effects, for objects with known light-curves.In this contribution we show results for more than 130 objects, about 100 of them with phase curves in two filters: V and R. We compute absolute magnitudes and phase coefficients in both filters, when available. The average values are HV = 6.39 ± 2.37, βV = (0.09 ± 0.32) mag per degree, HR = 5.38 ± 2.30, and βR = (0.08 ± 0.42) mag per degree.

  18. Chest tcpO2 changes during constant-load treadmill walking tests in patients with claudication.

    PubMed

    Ouedraogo, N; Feuilloy, M; Mahe, G; Leftheriotis, G; Saumet, J-L; Abraham, P

    2011-02-01

    Changes in chest transcutaneous-pO(2) at rest (ΔtcpO(2)) mimic absolute changes in arterial-pO(2) during moderate exercise, although the absolute starting values may dramatically differ. We retrospectively studied 485 patients (group 1), prospectively studied 292 new patients (group 2) and estimated the intra-test and the test-retest reproducibility of ΔtcpO(2) during constant-load treadmill tests: 3.2 km h(-1), 10% grade, using the cross correlation technique. Patients were classified into groups according to their best fit to nine pre-defined mathematic models. Respectively, 71% and 76% of patients of groups 1 and 2 fitted with a model showing a ΔtcpO(2) increase during and a decrease following exercise. Another 18% and 12% of the patients of groups 1 and 2 respectively fitted with a model that showed an abrupt decrease at exercise onset, a slow increase during walking and an overshoot in the recovery period, referred here as a walking-induced transcutaneous hack (WITH) profile. The mean r(max) value for the cross-correlation analysis was 0.919 ± 0.091 and 0.800 ± 0.129 for intra-test and test-retest reproducibility. Most profiles show the expected ΔtcpO(2) exercise-induced increase. Future studies are needed to confirm and explain the WITH profiles that we found, and screen for potential-associated diseases.

  19. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < ‑1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  20. Apparatus for absolute pressure measurement

    NASA Technical Reports Server (NTRS)

    Hecht, R. (Inventor)

    1969-01-01

    An absolute pressure sensor (e.g., the diaphragm of a capacitance manometer) was subjected to a superimposed potential to effectively reduce the mechanical stiffness of the sensor. This substantially increases the sensitivity of the sensor and is particularly useful in vacuum gauges. An oscillating component of the superimposed potential induced vibrations of the sensor. The phase of these vibrations with respect to that of the oscillating component was monitored, and served to initiate an automatic adjustment of the static component of the superimposed potential, so as to bring the sensor into resonance at the frequency of the oscillating component. This establishes a selected sensitivity for the sensor, since a definite relationship exists between resonant frequency and sensitivity.

  1. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < -1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  2. Absolute measurement of the extreme UV solar flux

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.; Ogawa, H. S.; Judge, D. L.; Phillips, E.

    1984-01-01

    A windowless rare-gas ionization chamber has been developed to measure the absolute value of the solar extreme UV flux in the 50-575-A region. Successful results were obtained on a solar-pointing sounding rocket. The ionization chamber, operated in total absorption, is an inherently stable absolute detector of ionizing UV radiation and was designed to be independent of effects from secondary ionization and gas effusion. The net error of the measurement is + or - 7.3 percent, which is primarily due to residual outgassing in the instrument, other errors such as multiple ionization, photoelectron collection, and extrapolation to the zero atmospheric optical depth being small in comparison. For the day of the flight, Aug. 10, 1982, the solar irradiance (50-575 A), normalized to unit solar distance, was found to be 5.71 + or - 0.42 x 10 to the 10th photons per sq cm sec.

  3. Absolute configuration of isovouacapenol C

    PubMed Central

    Fun, Hoong-Kun; Yodsaoue, Orapun; Karalai, Chatchanok; Chantrapromma, Suchada

    2010-01-01

    The title compound, C27H34O5 {systematic name: (4aR,5R,6R,6aS,7R,11aS,11bR)-4a,6-dihy­droxy-4,4,7,11b-tetra­methyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca­hydro­phenanthro[3,2-b]furan-5-yl benzoate}, is a cassane furan­oditerpene, which was isolated from the roots of Caesalpinia pulcherrima. The three cyclo­hexane rings are trans fused: two of these are in chair conformations with the third in a twisted half-chair conformation, whereas the furan ring is almost planar (r.m.s. deviation = 0.003 Å). An intra­molecular C—H⋯O inter­action generates an S(6) ring. The absolute configurations of the stereogenic centres at positions 4a, 5, 6, 6a, 7, 11a and 11b are R, R, R, S, R, S and R, respectively. In the crystal, mol­ecules are linked into infinite chains along [010] by O—H⋯O hydrogen bonds. C⋯O [3.306 (2)–3.347 (2) Å] short contacts and C—H⋯π inter­actions also occur. PMID:21588364

  4. Method and apparatus for making absolute range measurements

    DOEpatents

    Allison, S.W.; Cates, M.R.; Key, W.S.; Sanders, A.J.; Earl, D.D.

    1999-06-22

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a beam splitter''), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beam splitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention. 9 figs.

  5. Method and apparatus for making absolute range measurements

    DOEpatents

    Allison, Stephen W.; Cates, Michael R.; Key, William S.; Sanders, Alvin J.; Earl, Dennis D.

    1999-01-01

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a "beamsplitter"), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beamsplitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention.

  6. Defining Distance Learning and Distance Education.

    ERIC Educational Resources Information Center

    King, Frederick B.; Young, Michael F.; Drivere-Richmond, Kelly; Schrader, P. G.

    2001-01-01

    This paper offers precise definitions of distance learning and distance education, and their interrelationship. First, a single definition of learning is proposed, and then the concept of learning is broken down into three subcategories: instruction, exploration, and serendipity. Each is defined and the concepts of distance learning and distance…

  7. Absolute Income, Relative Income, and Happiness

    ERIC Educational Resources Information Center

    Ball, Richard; Chernova, Kateryna

    2008-01-01

    This paper uses data from the World Values Survey to investigate how an individual's self-reported happiness is related to (i) the level of her income in absolute terms, and (ii) the level of her income relative to other people in her country. The main findings are that (i) both absolute and relative income are positively and significantly…

  8. Investigating Absolute Value: A Real World Application

    ERIC Educational Resources Information Center

    Kidd, Margaret; Pagni, David

    2009-01-01

    Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of absolute values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that absolute value simply…

  9. Preschoolers' Success at Coding Absolute Size Values.

    ERIC Educational Resources Information Center

    Russell, James

    1980-01-01

    Forty-five 2-year-old and forty-five 3-year-old children coded relative and absolute sizes using 1.5-inch, 6-inch, and 18-inch cardboard squares. Results indicate that absolute coding is possible for children of this age. (Author/RH)

  10. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  11. Monolithically integrated absolute frequency comb laser system

    DOEpatents

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  12. Estimating the absolute wealth of households

    PubMed Central

    Gerkey, Drew; Hadley, Craig

    2015-01-01

    Abstract Objective To estimate the absolute wealth of households using data from demographic and health surveys. Methods We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. Findings The median absolute wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723–6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R2 = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Conclusion Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality. PMID:26170506

  13. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.

    2005-01-01

    We provide and overview of the developments in the field of high-accuracy absolute optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for Absolute Ranging (MSTAR) sensor is described along with novel applications of the sensor.

  14. Absolute instability of the Gaussian wake profile

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.; Aggarwal, Arun K.

    1987-01-01

    Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local absolute instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or absolute, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. Absolute instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of absolute instability with decreasing wake Reynolds number. If backflow is not allowed, absolute instability does not occur for wake Reynolds numbers smaller than about 38.

  15. Patient education interventions to improve physical activity in patients with intermittent claudication: a protocol for a systematic mixed-studies review

    PubMed Central

    Abaraogu, Ukachukwu Okoroafor; Dall, Philippa Margaret; Seenan, Christopher Andrew

    2016-01-01

    Introduction Peripheral arterial disease (PAD) and intermittent claudication (IC) decrease an individual's capacity to engage in physical activity (PA) with potentially negative effects on PA behaviour. Strategies to improve PA among this population may provide a range of positive health benefits. We present a protocol to assess the components of patient education interventions that improve PA capacity and PA behaviour in patients with PAD and IC. Methods and analysis Published peer-reviewed studies will be searched in the following databases: CINAHL, the Cochrane Library, OVID, ProQuest, AMED, MEDLINE, PsycINFO, Web of Science Core Collection and PEDro, to identify literature investigating the effect of patient education on PA of patients with PAD and IC, or studies that investigated patients' perceptions or experience with these interventions. Two authors will independently perform screening for study eligibility, result synthesis and then appraise study quality. For interventions without follow-up, primary outcome measures will include change in PA capacity, or change in free-living PA behaviour; where there was a follow-up postintervention, the primary outcome will be rate of adherence to PA behaviour improvement. A three-phase sequential explanatory synthesis of mixed studies will be employed to answer the research questions. Homogenous quantitative data will be analysed using a random-effects model of meta-analysis with results presented as relative risk for dichotomous outcomes and as weighted or standardised means for continuous outcomes. Qualitative data will be analysed using thematic synthesis. This review protocol is reported according to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines. Trial registration number CRD42015027314. PMID:27207628

  16. Introducing the Concept of the Minimally Important Difference to Determine a Clinically Relevant Change on Patient-Reported Outcome Measures in Patients with Intermittent Claudication

    SciTech Connect

    Conijn, Anne P.; Jonkers, Wilma; Rouwet, Ellen V.; Vahl, Anco C.; Reekers, Jim A.; Koelemay, Mark J. W.

    2015-10-15

    PurposeThe minimally important difference (MID) represents the smallest change in score on patient-reported outcome measures that is relevant to patients. The aim of this study was to introduce the MID for the Vascular Quality of Life Questionnaire (VascuQol) and the walking impairment questionnaire (WIQ) for patients with intermittent claudication (IC).MethodsIn this multicenter study, we recruited 294 patients with IC between July and October 2012. Patients completed the VascuQol, with scores ranging from 1 to 7 (worst to best), and the WIQ, with scores ranging from 0 to 1 (worst to best) at first visit and after 4 months follow-up. In addition, patients answered an anchor-question rating their health status compared to baseline, as being improved, unchanged, or deteriorated. The MID for improvement and deterioration was calculated by an anchor-based approach, and determined with the upper and lower limits of the 95 % confidence interval of the mean change of the group who had not changed according to the anchor-question.ResultsFor the MID analyses of the VascuQol and WIQ, 163 and 134 patients were included, respectively. The MID values for the VascuQol (mean baseline score 4.25) were 0.87 for improvement and 0.23 for deterioration. For the WIQ (mean baseline score 0.39), we found MID values of 0.11 and −0.03 for improvement and deterioration, respectively.ConclusionIn this study, we calculated the MID for the VascuQol and the WIQ. Applying these MID facilitates better interpretation of treatment outcomes and can help to set treatment goals for individual care.

  17. Cool flame quench distances

    NASA Technical Reports Server (NTRS)

    Ryason, P. R.; Hirsch, E.

    1974-01-01

    The results of a brief experimental investigation are presented which confirm the expectation that cool flame quenching distances should be larger than hot flame quenching distances. It is also discovered that whereas quenching distances for hot flames reach their minimum values near stoichiometric conditions, cool flame quenching distances are least under rich conditions. Rich conditions are well known to favor cool flame formation.

  18. Facilitating Distance Education.

    ERIC Educational Resources Information Center

    Rossman, Mark H., Ed.; Rossman, Maxine E., Ed.

    1995-01-01

    This collection of articles on distance learning reflects the perspectives and concerns of the learner and the facilitator of learning in distance education setting. Eight chapters are included: (1) "The Evolution and Advantages of Distance Education" (John E. Cantelon) traces the history of distance education and demonstrates how it transcends…

  19. Training for Distance Teaching through Distance Learning.

    ERIC Educational Resources Information Center

    Cadorath, Jill; Harris, Simon; Encinas, Fatima

    2002-01-01

    Describes a mixed-mode bachelor degree course in English language teaching at the Universidad Autonoma de Puebla (Mexico) that was designed to help practicing teachers write appropriate distance education materials by giving them the experience of being distance students. Includes a course outline and results of a course evaluation. (Author/LRW)

  20. Absolute magnitudes of trans-neptunian objects

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Alvarez-candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Morales, N.; Santos-Sanz, P.; Thirouin, A.

    2015-10-01

    Accurate measurements of diameters of trans- Neptunian objects are extremely complicated to obtain. Radiomatric techniques applied to thermal measurements can provide good results, but precise absolute magnitudes are needed to constrain diameters and albedos. Our objective is to measure accurate absolute magnitudes for a sample of trans- Neptunian objects, many of which have been observed, and modelled, by the "TNOs are cool" team, one of Herschel Space Observatory key projects grantes with ~ 400 hours of observing time. We observed 56 objects in filters V and R, if possible. These data, along with data available in the literature, was used to obtain phase curves and to measure absolute magnitudes by assuming a linear trend of the phase curves and considering magnitude variability due to rotational light-curve. In total we obtained 234 new magnitudes for the 56 objects, 6 of them with no reported previous measurements. Including the data from the literature we report a total of 109 absolute magnitudes.

  1. A New Gimmick for Assigning Absolute Configuration.

    ERIC Educational Resources Information Center

    Ayorinde, F. O.

    1983-01-01

    A five-step procedure is provided to help students in making the assignment absolute configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)

  2. The Simplicity Argument and Absolute Morality

    ERIC Educational Resources Information Center

    Mijuskovic, Ben

    1975-01-01

    In this paper the author has maintained that there is a similarity of thought to be found in the writings of Cudworth, Emerson, and Husserl in his investigation of an absolute system of morality. (Author/RK)

  3. Effect of Viewing Plane on Perceived Distances in Real and Virtual Environments

    ERIC Educational Resources Information Center

    Geuss, Michael N.; Stefanucci, Jeanine K.; Creem-Regehr, Sarah H.; Thompson, William B.

    2012-01-01

    Three experiments examined perceived absolute distance in a head-mounted display virtual environment (HMD-VE) and a matched real-world environment, as a function of the type and orientation of the distance viewed. In Experiment 1, participants turned and walked, without vision, a distance to match the viewed interval for both egocentric…

  4. Pseudomagnitude distances: Application to the Pleiades cluster

    NASA Astrophysics Data System (ADS)

    Chelli, A.; Duvert, G.

    2016-09-01

    The concept of pseudomagnitude has recently been introduced to estimate apparent stellar diameters using a strictly observational methodology. Pseudomagnitudes are distance indicators which have the remarkable property of being reddening free. In this study, we use Hipparcos parallax measurements to compute the mean absolute pseudomagnitudes of solar neighbourhood dwarf stars as a function of their spectral type. To illustrate the use of absolute pseudomagnitudes, we derive the distance moduli of 360 Pleiades stars and find that the centroid of their distribution is 5.715 ± 0.018, corresponding to a distance of 139.0 ± 1.2 pc. We locate the subset of ~50 Pleiades stars observed by Hipparcos at a mean distance of 135.5 ± 3.7 pc, thus confirming the frequently reported anomaly in the Hipparcos measurements of these stars. Table 3 is 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/593/L18

  5. Jasminum flexile flower absolute from India--a detailed comparison with three other jasmine absolutes.

    PubMed

    Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef

    2009-09-01

    Jasminum flexile flower absolute from the south of India and the corresponding vacuum headspace (VHS) sample of the absolute were analyzed using GC and GC-MS. Three other commercially available Indian jasmine absolutes from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower absolute, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed.

  6. Universal Cosmic Absolute and Modern Science

    NASA Astrophysics Data System (ADS)

    Kostro, Ludwik

    The official Sciences, especially all natural sciences, respect in their researches the principle of methodic naturalism i.e. they consider all phenomena as entirely natural and therefore in their scientific explanations they do never adduce or cite supernatural entities and forces. The purpose of this paper is to show that Modern Science has its own self-existent, self-acting, and self-sufficient Natural All-in Being or Omni-Being i.e. the entire Nature as a Whole that justifies the scientific methodic naturalism. Since this Natural All-in Being is one and only It should be considered as the own scientifically justified Natural Absolute of Science and should be called, in my opinion, the Universal Cosmic Absolute of Modern Science. It will be also shown that the Universal Cosmic Absolute is ontologically enormously stratified and is in its ultimate i.e. in its most fundamental stratum trans-reistic and trans-personal. It means that in its basic stratum. It is neither a Thing or a Person although It contains in Itself all things and persons with all other sentient and conscious individuals as well, On the turn of the 20th century the Science has begun to look for a theory of everything, for a final theory, for a master theory. In my opinion the natural Universal Cosmic Absolute will constitute in such a theory the radical all penetrating Ultimate Basic Reality and will substitute step by step the traditional supernatural personal Absolute.

  7. Going the Distance

    ERIC Educational Resources Information Center

    Waters, John K.

    2012-01-01

    Whoever said "Distance education begins in the 10th row" was taking a jab at the comatose kids at the back of his classroom, but the comment also taps into the old image of distance learners as disengaged themselves. That was then. Today, distance-learning programs are booming, in part due to demographic realities but also because recent advances…

  8. Foundations of Distance Education.

    ERIC Educational Resources Information Center

    Morabito, Margaret Gorts

    The foundations, development, and delivery of distance education were examined through a literature review and first-hand experience in administration and teaching in an international online school. The evolution of distance education was traced from the 1800s, when it was a print-based method of instruction conducted at a distance, through the…

  9. Distance Education Research.

    ERIC Educational Resources Information Center

    Curran, Chris

    1983-01-01

    Reviews six papers from the Open University Distance Education Research Group which cover the following topics: the credibility of distance education, admission systems, distance methods in adult basic education, the Universidad Estatal a Distancia (Costa Rica), Radio Ecca (Canary Islands), and the Open University (Great Britain). (EAO)

  10. Making Distance Education Borderless.

    ERIC Educational Resources Information Center

    Srisa-An, Wichit

    1997-01-01

    Begins with a tribute to Professor G. Ram Reddy (founder of Indira Gandhi National Open University), then focuses on enhancing the role of open universities in providing borderless distance education. Highlights include the need for open distance-education; philosophy and vision; the distance teaching system; the role of information technology;…

  11. Quantum theory allows for absolute maximal contextuality

    NASA Astrophysics Data System (ADS)

    Amaral, Barbara; Cunha, Marcelo Terra; Cabello, Adán

    2015-12-01

    Contextuality is a fundamental feature of quantum theory and a necessary resource for quantum computation and communication. It is therefore important to investigate how large contextuality can be in quantum theory. Linear contextuality witnesses can be expressed as a sum S of n probabilities, and the independence number α and the Tsirelson-like number ϑ of the corresponding exclusivity graph are, respectively, the maximum of S for noncontextual theories and for the theory under consideration. A theory allows for absolute maximal contextuality if it has scenarios in which ϑ /α approaches n . Here we show that quantum theory allows for absolute maximal contextuality despite what is suggested by the examination of the quantum violations of Bell and noncontextuality inequalities considered in the past. Our proof is not constructive and does not single out explicit scenarios. Nevertheless, we identify scenarios in which quantum theory allows for almost-absolute-maximal contextuality.

  12. Absolute calibration in vivo measurement systems

    SciTech Connect

    Kruchten, D.A.; Hickman, D.P.

    1991-02-01

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs.

  13. Stimulus probability effects in absolute identification.

    PubMed

    Kent, Christopher; Lamberts, Koen

    2016-05-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of presentation probability on both proportion correct and response times. The effects were moderated by the ubiquitous stimulus position effect. The accuracy and response time data were predicted by an exemplar-based model of perceptual cognition (Kent & Lamberts, 2005). The bow in discriminability was also attenuated when presentation probability for middle items was relatively high, an effect that will constrain future model development. The study provides evidence for item-specific learning in absolute identification. Implications for other theories of absolute identification are discussed. (PsycINFO Database Record

  14. Quantitative standards for absolute linguistic universals.

    PubMed

    Piantadosi, Steven T; Gibson, Edward

    2014-01-01

    Absolute linguistic universals are often justified by cross-linguistic analysis: If all observed languages exhibit a property, the property is taken to be a likely universal, perhaps specified in the cognitive or linguistic systems of language learners and users. In many cases, these patterns are then taken to motivate linguistic theory. Here, we show that cross-linguistic analysis will very rarely be able to statistically justify absolute, inviolable patterns in language. We formalize two statistical methods--frequentist and Bayesian--and show that in both it is possible to find strict linguistic universals, but that the numbers of independent languages necessary to do so is generally unachievable. This suggests that methods other than typological statistics are necessary to establish absolute properties of human language, and thus that many of the purported universals in linguistics have not received sufficient empirical justification.

  15. Absolute photoacoustic thermometry in deep tissue.

    PubMed

    Yao, Junjie; Ke, Haixin; Tai, Stephen; Zhou, Yong; Wang, Lihong V

    2013-12-15

    Photoacoustic thermography is a promising tool for temperature measurement in deep tissue. Here we propose an absolute temperature measurement method based on the dual temperature dependences of the Grüneisen parameter and the speed of sound in tissue. By taking ratiometric measurements at two adjacent temperatures, we can eliminate the factors that are temperature irrelevant but difficult to correct for in deep tissue. To validate our method, absolute temperatures of blood-filled tubes embedded ~9 mm deep in chicken tissue were measured in a biologically relevant range from 28°C to 46°C. The temperature measurement accuracy was ~0.6°C. The results suggest that our method can be potentially used for absolute temperature monitoring in deep tissue during thermotherapy.

  16. Molecular iodine absolute frequencies. Final report

    SciTech Connect

    Sansonetti, C.J.

    1990-06-25

    Fifty specified lines of {sup 127}I{sub 2} were studied by Doppler-free frequency modulation spectroscopy. For each line the classification of the molecular transition was determined, hyperfine components were identified, and one well-resolved component was selected for precise determination of its absolute frequency. In 3 cases, a nearby alternate line was selected for measurement because no well-resolved component was found for the specified line. Absolute frequency determinations were made with an estimated uncertainty of 1.1 MHz by locking a dye laser to the selected hyperfine component and measuring its wave number with a high-precision Fabry-Perot wavemeter. For each line results of the absolute measurement, the line classification, and a Doppler-free spectrum are given.

  17. A distance-independent calibration of the luminosity of type Ia supernovae and the Hubble constant

    NASA Technical Reports Server (NTRS)

    Leibundgut, Bruno; Pinto, Philip A.

    1992-01-01

    The absolute magnitude of SNe Ia at maximum is calibrated here using radioactive decay models for the light curve and a minimum of assumptions. The absolute magnitude parameter space is studied using explosion models and a range of rise times, and absolute B magnitudes at maximum are used to derive a range of the H0 and the distance to the Virgo Cluster from SNe Ia. Rigorous limits for H0 of 45 and 105 km/s/Mpc are derived.

  18. Lunar eclipse photometry: absolute luminance measurements and modeling.

    PubMed

    Hernitschek, Nina; Schmidt, Elmar; Vollmer, Michael

    2008-12-01

    The Moon's time-dependent luminance was determined during the 9 February 1990 and 3 March 2007 total lunar eclipses by using calibrated, industry standard photometers. After the results were corrected to unit air mass and to standard distances for both Moon and Sun, an absolute calibration was accomplished by using the Sun's known luminance and a pre-eclipse lunar albedo of approximately 13.5%. The measured minimum level of brightness in the total phase of both eclipses was relatively high, namely -3.32 m(vis) and -1.7 m(vis), which hints at the absence of pronounced stratospheric aerosol. The light curves were modeled in such a way as to let the Moon move through an artificial Earth shadow composed of a multitude of disk and ring zones, containing a relative luminance data set from an atmospheric radiative transfer calculation. PMID:19037352

  19. Lunar eclipse photometry: absolute luminance measurements and modeling.

    PubMed

    Hernitschek, Nina; Schmidt, Elmar; Vollmer, Michael

    2008-12-01

    The Moon's time-dependent luminance was determined during the 9 February 1990 and 3 March 2007 total lunar eclipses by using calibrated, industry standard photometers. After the results were corrected to unit air mass and to standard distances for both Moon and Sun, an absolute calibration was accomplished by using the Sun's known luminance and a pre-eclipse lunar albedo of approximately 13.5%. The measured minimum level of brightness in the total phase of both eclipses was relatively high, namely -3.32 m(vis) and -1.7 m(vis), which hints at the absence of pronounced stratospheric aerosol. The light curves were modeled in such a way as to let the Moon move through an artificial Earth shadow composed of a multitude of disk and ring zones, containing a relative luminance data set from an atmospheric radiative transfer calculation.

  20. Absolute properties of the eclipsing binary star IM Persei

    SciTech Connect

    Lacy, Claud H. Sandberg; Torres, Guillermo; Fekel, Francis C.; Muterspaugh, Matthew W.; Southworth, John E-mail: gtorres@cfa.harvard.edu E-mail: matthew1@coe.tsuniv.edu

    2015-01-01

    IM Per is a detached A7 eccentric eclipsing binary star. We have obtained extensive measurements of the light curve (28,225 differential magnitude observations) and radial velocity curve (81 spectroscopic observations) which allow us to fit orbits and determine the absolute properties of the components very accurately: masses of 1.7831 ± 0.0094 and 1.7741 ± 0.0097 solar masses, and radii of 2.409 ± 0.018 and 2.366 ± 0.017 solar radii. The orbital period is 2.25422694(15) days and the eccentricity is 0.0473(26). A faint third component was detected in the analysis of the light curves, and also directly observed in the spectra. The observed rate of apsidal motion is consistent with theory (U = 151.4 ± 8.4 year). We determine a distance to the system of 566 ± 46 pc.

  1. Precision distances with spiral galaxy apparent diameters

    NASA Astrophysics Data System (ADS)

    Steer, Ian

    2016-01-01

    Spiral galaxy diameters offer the oldest extragalactic distance indicator known. Although outdated and hitherto imprecise, two spiral diameter-based distance indicators applied in the 1980s can be tested, calibrated, and re-established for precision era use, based on abundant redshift-independent distances data available in NED-D. Indicator one employs the largest Giant Spiral Galaxies, which have an absolute isophotal major diameter of ~70 +/- 10 kpc, offering standard ruler-based distances with <10% precision. Indicator two employs the diameter-magnitude relation for spirals in general, as a secondary indicator, offering ~20% precision. The ruler-based indicator is the only indicator with <10% precision able to independently calibrate type Ia supernovae-based distances at cosmological distances. The secondary-based indicator is the only indicator with 20% precision applicable to more galaxies than in current Tully-Fisher surveys. The primary indicator gives researchers a new tool to confirm or refute if, as currently believed, universal expansion is accelerating. The secondary indicator gives researchers a new path toward acquiring a more complete 3D picture of the local universe and potentially, because the majority of galaxies in the universe are spirals, the distant universe.

  2. Absolute Stability And Hyperstability In Hilbert Space

    NASA Technical Reports Server (NTRS)

    Wen, John Ting-Yung

    1989-01-01

    Theorems on stabilities of feedback control systems proved. Paper presents recent developments regarding theorems of absolute stability and hyperstability of feedforward-and-feedback control system. Theorems applied in analysis of nonlinear, adaptive, and robust control. Extended to provide sufficient conditions for stability in system including nonlinear feedback subsystem and linear time-invariant (LTI) feedforward subsystem, state space of which is Hilbert space, and input and output spaces having finite numbers of dimensions. (In case of absolute stability, feedback subsystem memoryless and possibly time varying. For hyperstability, feedback system dynamical system.)

  3. Peripheral Arterial Disease and Claudication

    MedlinePlus

    ... of fatty deposits inside them. This is called atherosclerosis. If you have PAD, your arms, and more ... also more likely in people who already have atherosclerosis in other arteries, such as the arteries in ...

  4. Absolute Depth Sensitivity in Cat Primary Visual Cortex under Natural Viewing Conditions.

    PubMed

    Pigarev, Ivan N; Levichkina, Ekaterina V

    2016-01-01

    Mechanisms of 3D perception, investigated in many laboratories, have defined depth either relative to the fixation plane or to other objects in the visual scene. It is obvious that for efficient perception of the 3D world, additional mechanisms of depth constancy could operate in the visual system to provide information about absolute distance. Neurons with properties reflecting some features of depth constancy have been described in the parietal and extrastriate occipital cortical areas. It has also been shown that, for some neurons in the visual area V1, responses to stimuli of constant angular size differ at close and remote distances. The present study was designed to investigate whether, in natural free gaze viewing conditions, neurons tuned to absolute depths can be found in the primary visual cortex (area V1). Single-unit extracellular activity was recorded from the visual cortex of waking cats sitting on a trolley in front of a large screen. The trolley was slowly approaching the visual scene, which consisted of stationary sinusoidal gratings of optimal orientation rear-projected over the whole surface of the screen. Each neuron was tested with two gratings, with spatial frequency of one grating being twice as high as that of the other. Assuming that a cell is tuned to a spatial frequency, its maximum response to the grating with a spatial frequency twice as high should be shifted to a distance half way closer to the screen in order to attain the same size of retinal projection. For hypothetical neurons selective to absolute depth, location of the maximum response should remain at the same distance irrespective of the type of stimulus. It was found that about 20% of neurons in our experimental paradigm demonstrated sensitivity to particular distances independently of the spatial frequencies of the gratings. We interpret these findings as an indication of the use of absolute depth information in the primary visual cortex. PMID:27547179

  5. Absolute Depth Sensitivity in Cat Primary Visual Cortex under Natural Viewing Conditions

    PubMed Central

    Pigarev, Ivan N.; Levichkina, Ekaterina V.

    2016-01-01

    Mechanisms of 3D perception, investigated in many laboratories, have defined depth either relative to the fixation plane or to other objects in the visual scene. It is obvious that for efficient perception of the 3D world, additional mechanisms of depth constancy could operate in the visual system to provide information about absolute distance. Neurons with properties reflecting some features of depth constancy have been described in the parietal and extrastriate occipital cortical areas. It has also been shown that, for some neurons in the visual area V1, responses to stimuli of constant angular size differ at close and remote distances. The present study was designed to investigate whether, in natural free gaze viewing conditions, neurons tuned to absolute depths can be found in the primary visual cortex (area V1). Single-unit extracellular activity was recorded from the visual cortex of waking cats sitting on a trolley in front of a large screen. The trolley was slowly approaching the visual scene, which consisted of stationary sinusoidal gratings of optimal orientation rear-projected over the whole surface of the screen. Each neuron was tested with two gratings, with spatial frequency of one grating being twice as high as that of the other. Assuming that a cell is tuned to a spatial frequency, its maximum response to the grating with a spatial frequency twice as high should be shifted to a distance half way closer to the screen in order to attain the same size of retinal projection. For hypothetical neurons selective to absolute depth, location of the maximum response should remain at the same distance irrespective of the type of stimulus. It was found that about 20% of neurons in our experimental paradigm demonstrated sensitivity to particular distances independently of the spatial frequencies of the gratings. We interpret these findings as an indication of the use of absolute depth information in the primary visual cortex. PMID:27547179

  6. Absolute Depth Sensitivity in Cat Primary Visual Cortex under Natural Viewing Conditions.

    PubMed

    Pigarev, Ivan N; Levichkina, Ekaterina V

    2016-01-01

    Mechanisms of 3D perception, investigated in many laboratories, have defined depth either relative to the fixation plane or to other objects in the visual scene. It is obvious that for efficient perception of the 3D world, additional mechanisms of depth constancy could operate in the visual system to provide information about absolute distance. Neurons with properties reflecting some features of depth constancy have been described in the parietal and extrastriate occipital cortical areas. It has also been shown that, for some neurons in the visual area V1, responses to stimuli of constant angular size differ at close and remote distances. The present study was designed to investigate whether, in natural free gaze viewing conditions, neurons tuned to absolute depths can be found in the primary visual cortex (area V1). Single-unit extracellular activity was recorded from the visual cortex of waking cats sitting on a trolley in front of a large screen. The trolley was slowly approaching the visual scene, which consisted of stationary sinusoidal gratings of optimal orientation rear-projected over the whole surface of the screen. Each neuron was tested with two gratings, with spatial frequency of one grating being twice as high as that of the other. Assuming that a cell is tuned to a spatial frequency, its maximum response to the grating with a spatial frequency twice as high should be shifted to a distance half way closer to the screen in order to attain the same size of retinal projection. For hypothetical neurons selective to absolute depth, location of the maximum response should remain at the same distance irrespective of the type of stimulus. It was found that about 20% of neurons in our experimental paradigm demonstrated sensitivity to particular distances independently of the spatial frequencies of the gratings. We interpret these findings as an indication of the use of absolute depth information in the primary visual cortex.

  7. Absolute Points for Multiple Assignment Problems

    ERIC Educational Resources Information Center

    Adlakha, V.; Kowalski, K.

    2006-01-01

    An algorithm is presented to solve multiple assignment problems in which a cost is incurred only when an assignment is made at a given cell. The proposed method recursively searches for single/group absolute points to identify cells that must be loaded in any optimal solution. Unlike other methods, the first solution is the optimal solution. The…

  8. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  9. Stimulus Probability Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Kent, Christopher; Lamberts, Koen

    2016-01-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…

  10. Teaching Absolute Value Inequalities to Mature Students

    ERIC Educational Resources Information Center

    Sierpinska, Anna; Bobos, Georgeana; Pruncut, Andreea

    2011-01-01

    This paper gives an account of a teaching experiment on absolute value inequalities, whose aim was to identify characteristics of an approach that would realize the potential of the topic to develop theoretical thinking in students enrolled in prerequisite mathematics courses at a large, urban North American university. The potential is…

  11. Solving Absolute Value Equations Algebraically and Geometrically

    ERIC Educational Resources Information Center

    Shiyuan, Wei

    2005-01-01

    The way in which students can improve their comprehension by understanding the geometrical meaning of algebraic equations or solving algebraic equation geometrically is described. Students can experiment with the conditions of the absolute value equation presented, for an interesting way to form an overall understanding of the concept.

  12. Increasing Capacity: Practice Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Dodds, Pennie; Donkin, Christopher; Brown, Scott D.; Heathcote, Andrew

    2011-01-01

    In most of the long history of the study of absolute identification--since Miller's (1956) seminal article--a severe limit on performance has been observed, and this limit has resisted improvement even by extensive practice. In a startling result, Rouder, Morey, Cowan, and Pfaltz (2004) found substantially improved performance with practice in the…

  13. Absolute Radiometric Calibration Of The Thematic Mapper

    NASA Astrophysics Data System (ADS)

    Slater, P. N.; Biggar, S. F.; Holm, R. G.; Jackson, R. D.; Mao, Y.; Moran, M. S.; Palmer, J. M.; Yuan, B.

    1986-11-01

    The results are presented of five in-flight absolute radiometric calibrations, made in the period July 1984 to November 1985, at White Sands, New Mexico, of the solar reflective bands of the Landsat-5 Thematic Mapper (TM) . The 23 bandcalibrations made on the five dates show a ± 2.8% RMS variation from the mean as a percentage of the mean.

  14. On Relative and Absolute Conviction in Mathematics

    ERIC Educational Resources Information Center

    Weber, Keith; Mejia-Ramos, Juan Pablo

    2015-01-01

    Conviction is a central construct in mathematics education research on justification and proof. In this paper, we claim that it is important to distinguish between absolute conviction and relative conviction. We argue that researchers in mathematics education frequently have not done so and this has lead to researchers making unwarranted claims…

  15. The orbit of Phi Cygni measured with long-baseline optical interferometry - Component masses and absolute magnitudes

    NASA Technical Reports Server (NTRS)

    Armstrong, J. T.; Hummel, C. A.; Quirrenbach, A.; Buscher, D. F.; Mozurkewich, D.; Vivekanand, M.; Simon, R. S.; Denison, C. S.; Johnston, K. J.; Pan, X.-P.

    1992-01-01

    The orbit of the double-lined spectroscopic binary Phi Cygni, the distance to the system, and the masses and absolute magnitudes of its components are presented via measurements with the Mar III Optical Interferometer. On the basis of a reexamination of the spectroscopic data of Rach & Herbig (1961), the values and uncertainties are adopted for the period and the projected semimajor axes from the present fit to the spectroscopic data and the values of the remaining elements from the present fit to the Mark III data. The elements of the true orbit are derived, and the masses and absolute magnitudes of the components, and the distance to the system are calculated.

  16. Traversing psychological distance.

    PubMed

    Liberman, Nira; Trope, Yaacov

    2014-07-01

    Traversing psychological distance involves going beyond direct experience, and includes planning, perspective taking, and contemplating counterfactuals. Consistent with this view, temporal, spatial, and social distances as well as hypotheticality are associated, affect each other, and are inferred from one another. Moreover, traversing all distances involves the use of abstraction, which we define as forming a belief about the substitutability for a specific purpose of subjectively distinct objects. Indeed, across many instances of both abstraction and psychological distancing, more abstract constructs are used for more distal objects. Here, we describe the implications of this relation for prediction, choice, communication, negotiation, and self-control. We ask whether traversing distance is a general mental ability and whether distance should replace expectancy in expected-utility theories. PMID:24726527

  17. A VLBI resolution of the Pleiades distance controversy.

    PubMed

    Melis, Carl; Reid, Mark J; Mioduszewski, Amy J; Stauffer, John R; Bower, Geoffrey C

    2014-08-29

    Because of its proximity and its youth, the Pleiades open cluster of stars has been extensively studied and serves as a cornerstone for our understanding of the physical properties of young stars. This role is called into question by the "Pleiades distance controversy," wherein the cluster distance of 120.2 ± 1.5 parsecs (pc) as measured by the optical space astrometry mission Hipparcos is significantly different from the distance of 133.5 ± 1.2 pc derived with other techniques. We present an absolute trigonometric parallax distance measurement to the Pleiades cluster that uses very long baseline radio interferometry (VLBI). This distance of 136.2 ± 1.2 pc is the most accurate and precise yet presented for the cluster and is incompatible with the Hipparcos distance determination. Our results cement existing astrophysical models for Pleiades-age stars.

  18. The Extragalactic Distance Scale

    NASA Astrophysics Data System (ADS)

    Livio, Mario; Donahue, Megan; Panagia, Nino

    1997-07-01

    Participants; Preface; Foreword; Early history of the distance scale problem, S. van den Bergh; Cosmology: From Hubble to HST, M. S. Turner; Age constraints nucleocosmochronology, J. Truran; The ages of globular clusters, P. Demarque; The linearity of the Hubble flow M. Postman; Gravitational lensing and the extragalactic distance scale, R. D. Blandford andT . Kundic; Using the cosmic microwave background to constrain the Hubble constant A. Lasenby and T M. Jones; Cepheids as distance indicators, N. R. Tanvir; The I-band Tully-Fisher relation and the Hubble constant, R. Giovanell; The calibration of type 1a supernovae as standard candles, A. Saha; Focusing in on the Hubble constant, G. A. Tammann & M. Federspiel; Interim report on the calibration of the Tully-Fisher relation in the HST Key Project to measure the Hubble constant, J. Mould et al.; Hubble Space Telescope Key Project on the extragalactic distance scale, W. L. Freedman, B. F. Madore and T R. C. Kennicutt; Novae as distance indicators, M. Livio; Verifying the planetary nebula luminosity function method, G. H. Jacoby; On the possible use of radio supernovae for distance determinations, K. W. Weiler et al.; Post-AGB stars as standard candles, H. Bond; Helium core flash at the tip of the red giant branch: a population II distance indicator, B. F. Madore, W. L. Freedman and T S. Sakai; Globular clusters as distance indicators, B. C. Whitmore; Detached eclipsing binaries as primary distance and age indicators, B. Paczynski; Light echoes: geometric measurement of galaxy distances, W. B. Sparks; The SBF survey of galaxy distances J. L. Tonry; Extragalactic distance scales: The long and short of it, V. Trimble.

  19. Photometric distances to nine dark globules

    NASA Astrophysics Data System (ADS)

    Maheswar, G.; Bhatt, H. C.

    2006-07-01

    Distances to nine dark globules are determined by a method using optical (VRI) and near-infrared (near-IR) (JHK) photometry of stars projected towards the field containing the globules. In this method, we compute intrinsic colour indices of stars projected towards the direction of the globule by dereddening the observed colour indices using various trial values of extinction AV and a standard extinction law. These computed intrinsic colour indices for each star are then compared with the intrinsic colour indices of normal main-sequence stars and a spectral type is assigned to the star for which the computed colour indices best match with the standard intrinsic colour indices. Distances (d) to the stars are determined using the AV and absolute magnitude (MV) corresponding to the spectral types thus obtained. A distance versus extinction plot is made and the distance at which AV undergoes a sharp rise is taken to be the distance to the globule. All the clouds studied in this work are in the distance range 160-400pc. The estimated distances to dark globules LDN 544, LDN 549, LDN 567, LDN 543, LDN 1113, LDN 1031, LDN 1225, LDN 1252 and LDN 1257 are 180 +/- 35, 200 +/- 40, 180 +/- 35, 160 +/- 30, 350 +/- 70, 200 +/- 40, 400 +/- 80, 250 +/- 50 and 250 +/- 50pc, respectively. Using the distances determined, we have estimated the masses of the globules and the far-IR luminosity of the IRAS sources associated with them. The mass of the clouds studied are in the range 10-200Msolar.

  20. Suppression of Systematic Errors of Electronic Distance Meters for Measurement of Short Distances.

    PubMed

    Braun, Jaroslav; Štroner, Martin; Urban, Rudolf; Dvoček, Filip

    2015-08-06

    In modern industrial geodesy, high demands are placed on the final accuracy, with expectations currently falling below 1 mm. The measurement methodology and surveying instruments used have to be adjusted to meet these stringent requirements, especially the total stations as the most often used instruments. A standard deviation of the measured distance is the accuracy parameter, commonly between 1 and 2 mm. This parameter is often discussed in conjunction with the determination of the real accuracy of measurements at very short distances (5-50 m) because it is generally known that this accuracy cannot be increased by simply repeating the measurement because a considerable part of the error is systematic. This article describes the detailed testing of electronic distance meters to determine the absolute size of their systematic errors, their stability over time, their repeatability and the real accuracy of their distance measurement. Twenty instruments (total stations) have been tested, and more than 60,000 distances in total were measured to determine the accuracy and precision parameters of the distance meters. Based on the experiments' results, calibration procedures were designed, including a special correction function for each instrument, whose usage reduces the standard deviation of the measurement of distance by at least 50%.

  1. Suppression of Systematic Errors of Electronic Distance Meters for Measurement of Short Distances

    PubMed Central

    Braun, Jaroslav; Štroner, Martin; Urban, Rudolf; Dvořáček, Filip

    2015-01-01

    In modern industrial geodesy, high demands are placed on the final accuracy, with expectations currently falling below 1 mm. The measurement methodology and surveying instruments used have to be adjusted to meet these stringent requirements, especially the total stations as the most often used instruments. A standard deviation of the measured distance is the accuracy parameter, commonly between 1 and 2 mm. This parameter is often discussed in conjunction with the determination of the real accuracy of measurements at very short distances (5–50 m) because it is generally known that this accuracy cannot be increased by simply repeating the measurement because a considerable part of the error is systematic. This article describes the detailed testing of electronic distance meters to determine the absolute size of their systematic errors, their stability over time, their repeatability and the real accuracy of their distance measurement. Twenty instruments (total stations) have been tested, and more than 60,000 distances in total were measured to determine the accuracy and precision parameters of the distance meters. Based on the experiments’ results, calibration procedures were designed, including a special correction function for each instrument, whose usage reduces the standard deviation of the measurement of distance by at least 50%. PMID:26258777

  2. A NEW METHOD FOR MEASURING EXTRAGALACTIC DISTANCES

    SciTech Connect

    Yoshii, Yuzuru; Minezaki, Takeo; Kobayashi, Yukiyasu; Koshida, Shintaro; Peterson, Bruce A.

    2014-03-20

    We have pioneered a new method for the measurement of extragalactic distances. This method uses the time lag between variations in the short wavelength and long wavelength light from an active galactic nucleus (AGN), based on a quantitative physical model of dust reverberation that relates the time lag to the absolute luminosity of the AGN. We use the large homogeneous data set from intensive monitoring observations in optical and near-infrared wavelength bands with the dedicated 2 m MAGNUM telescope to obtain the distances to 17 AGNs in the redshift range z = 0.0024 to z = 0.0353. These distance measurements are compared with distances measured using Cepheid variable stars, and are used to infer that H {sub 0} = 73 ± 3 (random) km s{sup –1} Mpc{sup –1}. The systematic error in H {sub 0} is examined, and the uncertainty in the size distribution of dust grains is the largest source of the systematic error, which is much reduced for a sample of AGNs for which their parameter values in the model of dust reverberation are individually measured. This AGN time lag method can be used beyond 30 Mpc, the farthest distance reached by extragalactic Cepheids, and can be extended to high-redshift quasi-stellar objects.

  3. Distance Learning. PEPNet Tipsheet

    ERIC Educational Resources Information Center

    Keefe, Barbara, Comp.

    2002-01-01

    Distance learning is the separation of teacher and student by time and space. Rapid advances in communications technology have allowed distance learning to become one of the fastest-growing trends in higher education. College courses are being delivered across a highway that is global in scope. Today, two thirds of the 4,000 accredited colleges…

  4. Is Distance Learning Transformational?

    ERIC Educational Resources Information Center

    Hoskins, Barbara J.

    2013-01-01

    Is distance learning transformational? The author heard this question posed to a panel of faculty members during Distance Education Week activities. After reflecting upon her own students' reaction to her syllabus, her answer to the question changed from an initial, enthusiastic "yes" to a reflective "maybe," given the most favorable environment.…

  5. Education at a Distance.

    ERIC Educational Resources Information Center

    Maffett, Sheryl Price

    2007-01-01

    Distance learning has been around since the old "course in a box" correspondence classes, but with the advent of sophisticated online course management systems, learning at a distance is contributing to a major paradigm shift in higher education. That shift includes applying corporate concepts to education--students, for example, are "consumers,"…

  6. Biomechanics of Distance Running.

    ERIC Educational Resources Information Center

    Cavanagh, Peter R., Ed.

    Contributions from researchers in the field of running mechanics are included in the 13 chapters of this book. The following topics are covered: (1) "The Mechanics of Distance Running: A Historical Perspective" (Peter Cavanagh); (2) "Stride Length in Distance Running: Velocity, Body Dimensions, and Added Mass Effects" (Peter Cavanagh, Rodger…

  7. Mentoring Distance Learners.

    ERIC Educational Resources Information Center

    Zeeb, Patricia

    2000-01-01

    Defines mentoring, focusing on its use in distance education. Outlines categories of mentoring--traditional, peer, group or team, and online or virtual (telementoring). Discusses mentoring and technological change types of mentors in distance education classes; the role of computer-mediated communications; and decreasing attrition by pairing…

  8. An absolute measure for a key currency

    NASA Astrophysics Data System (ADS)

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

    It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no absolute general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an absolute measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.

  9. Probing absolute spin polarization at the nanoscale.

    PubMed

    Eltschka, Matthias; Jäck, Berthold; Assig, Maximilian; Kondrashov, Oleg V; Skvortsov, Mikhail A; Etzkorn, Markus; Ast, Christian R; Kern, Klaus

    2014-12-10

    Probing absolute values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polarized scanning tunneling microscopy that combines the probing capability of the absolute values of spin polarization with precise control at the atomic scale. We utilize our novel approach to measure the locally resolved spin polarization of magnetic Co nanoislands on Cu(111). We find that the spin polarization is enhanced by 65% when increasing the width of the tunnel barrier by only 2.3 Å due to the different decay of the electron orbitals into vacuum. PMID:25423049

  10. Absolute radiometry and the solar constant

    NASA Technical Reports Server (NTRS)

    Willson, R. C.

    1974-01-01

    A series of active cavity radiometers (ACRs) are described which have been developed as standard detectors for the accurate measurement of irradiance in absolute units. It is noted that the ACR is an electrical substitution calorimeter, is designed for automatic remote operation in any environment, and can make irradiance measurements in the range from low-level IR fluxes up to 30 solar constants with small absolute uncertainty. The instrument operates in a differential mode by chopping the radiant flux to be measured at a slow rate, and irradiance is determined from two electrical power measurements together with the instrumental constant. Results are reported for measurements of the solar constant with two types of ACRs. The more accurate measurement yielded a value of 136.6 plus or minus 0.7 mW/sq cm (1.958 plus or minus 0.010 cal/sq cm per min).

  11. From Hubble's NGSL to Absolute Fluxes

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Lindler, Don

    2012-01-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.

  12. Impact of Winko on absolute discharges.

    PubMed

    Balachandra, Krishna; Swaminath, Sam; Litman, Larry C

    2004-01-01

    In Canada, case laws have had a significant impact on the way mentally ill offenders are managed, both in the criminal justice system and in the forensic mental health system. The Supreme Court of Canada's decision with respect to Winko has set a major precedent in the application of the test of significant risk to the safety of the public in making dispositions by the Ontario Review Board and granting absolute discharges to the mentally ill offenders in the forensic health system. Our study examines the impact of the Supreme Court of Canada's decision before and after Winko. The results show that the numbers of absolute discharges have increased post-Winko, which was statistically significant, but there could be other factors influencing this increase.

  13. Absolute-magnitude distributions of supernovae

    SciTech Connect

    Richardson, Dean; Wright, John; Jenkins III, Robert L.; Maddox, Larry

    2014-05-01

    The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

  14. Absolute and relative dosimetry for ELIMED

    SciTech Connect

    Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.

    2013-07-26

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  15. Revised Pioneer 10 absolute electron intensities in the inner Jovian magnetosphere

    NASA Technical Reports Server (NTRS)

    Baker, D. N.; Van Allen, J. A.

    1977-01-01

    Improved techniques for the analysis of Pioneer 10 Jupiter encounter data are used to obtain significantly more reliable values for energetic electron (Ee less than 21 MeV) intensities within the inner magnetosphere. The revised absolute intensities of electrons in the energy range 0.06-21 MeV are less than previous estimates by factors as great as 10 for L not exceeding 6. Previously published intensities at greater radial distances for Ee less than 21 MeV and at all radial distances for Ee greater than 21 MeV are not affected by the revisions.

  16. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1985-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  17. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  18. Relative errors can cue absolute visuomotor mappings.

    PubMed

    van Dam, Loes C J; Ernst, Marc O

    2015-12-01

    When repeatedly switching between two visuomotor mappings, e.g. in a reaching or pointing task, adaptation tends to speed up over time. That is, when the error in the feedback corresponds to a mapping switch, fast adaptation occurs. Yet, what is learned, the relative error or the absolute mappings? When switching between mappings, errors with a size corresponding to the relative difference between the mappings will occur more often than other large errors. Thus, we could learn to correct more for errors with this familiar size (Error Learning). On the other hand, it has been shown that the human visuomotor system can store several absolute visuomotor mappings (Mapping Learning) and can use associated contextual cues to retrieve them. Thus, when contextual information is present, no error feedback is needed to switch between mappings. Using a rapid pointing task, we investigated how these two types of learning may each contribute when repeatedly switching between mappings in the absence of task-irrelevant contextual cues. After training, we examined how participants changed their behaviour when a single error probe indicated either the often-experienced error (Error Learning) or one of the previously experienced absolute mappings (Mapping Learning). Results were consistent with Mapping Learning despite the relative nature of the error information in the feedback. This shows that errors in the feedback can have a double role in visuomotor behaviour: they drive the general adaptation process by making corrections possible on subsequent movements, as well as serve as contextual cues that can signal a learned absolute mapping. PMID:26280315

  19. The absolute spectrophotometric catalog by Anita Cochran

    NASA Astrophysics Data System (ADS)

    Burnashev, V. I.; Burnasheva, B. A.; Ruban, E. V.; Hagen-Torn, E. I.

    2014-06-01

    The absolute spectrophotometric catalog by Anita Cochran is presented in a machine-readable form. The catalog systematizes observations acquired at the McDonald Observatory in 1977-1978. The data are compared with other sources, in particular, the calculated broadband stellar magnitudes are compared with photometric observations by other authors, to show that the observational data given in the catalog are reliable and suitable for a variety of applications. Observations of variable stars of different types make Cochran's catalog especially valuable.

  20. Absolute magnitudes and kinematics of barium stars.

    NASA Astrophysics Data System (ADS)

    Gomez, A. E.; Luri, X.; Grenier, S.; Prevot, L.; Mennessier, M. O.; Figueras, F.; Torra, J.

    1997-03-01

    The absolute magnitude of barium stars has been obtained from kinematical data using a new algorithm based on the maximum-likelihood principle. The method allows to separate a sample into groups characterized by different mean absolute magnitudes, kinematics and z-scale heights. It also takes into account, simultaneously, the censorship in the sample and the errors on the observables. The method has been applied to a sample of 318 barium stars. Four groups have been detected. Three of them show a kinematical behaviour corresponding to disk population stars. The fourth group contains stars with halo kinematics. The luminosities of the disk population groups spread a large range. The intrinsically brightest one (M_v_=-1.5mag, σ_M_=0.5mag) seems to be an inhomogeneous group containing barium binaries as well as AGB single stars. The most numerous group (about 150 stars) has a mean absolute magnitude corresponding to stars in the red giant branch (M_v_=0.9mag, σ_M_=0.8mag). The third group contains barium dwarfs, the obtained mean absolute magnitude is characteristic of stars on the main sequence or on the subgiant branch (M_v_=3.3mag, σ_M_=0.5mag). The obtained mean luminosities as well as the kinematical results are compatible with an evolutionary link between barium dwarfs and classical barium giants. The highly luminous group is not linked with these last two groups. More high-resolution spectroscopic data will be necessary in order to better discriminate between barium and non-barium stars.

  1. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound. PMID:20070087

  2. A Methodology for Absolute Isotope Composition Measurement

    NASA Astrophysics Data System (ADS)

    Shen, J. J.; Lee, D.; Liang, W.

    2007-12-01

    Double spike technique was a well defined method for isotope composition measurement by TIMS of samples which have natural mass fractionation effect, but it is still a problem to define the isotope composition for double spike itself. In this study, we modified the old double spike technique and found that we could use the modified technique to solve the ¡§true¡¨ isotope composition of double spike itself. According the true isotope composition of double spike, we can measure the absolute isotope composition if the sample has natural fractionation effect. A new vector analytical method has been developed in order to obtain the true isotopic composition of a 42Ca-48Ca double spike, and this is achieved by using two different sample-spike mixtures combined with the double spike and the natural Ca data. Because the natural sample, the two mixtures, and the spike should all lie on a single mixing line, we are able to constrain the true isotopic composition of our double spike using this new approach. This method not only can be used in Ca system but also in Ti, Cr, Fe, Ni, Zn, Mo, Ba and Pb systems. The absolute double spike isotopic ratio is important, which can save a lot of time to check different reference standards. Especially for Pb, radiogenic isotope system, the decay systems embodied in three of four naturally occurring isotopes induce difficult to obtain true isotopic ratios for absolute dating.

  3. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound.

  4. The Carina Project: Absolute and Relative Calibrations

    NASA Astrophysics Data System (ADS)

    Corsi, C. E.; Bono, G.; Walker, A. R.; Brocato, E.; Buonanno, R.; Caputo, F.; Castellani, M.; Castellani, V.; Dall'Ora, M.; Marconi, M.; Monelli, M.; Nonino, M.; Pulone, L.; Ripepi, V.; Smith, H. A.

    We discuss the reduction strategy adopted to perform the relative and the absolute calibration of the Wide Field Imager (WFI) available at the 2.2m ESO/MPI telescope and of the Mosaic Camera (MC) available at the 4m CTIO Blanco telescope. To properly constrain the occurrence of deceptive systematic errors in the relative calibration we observed with each chip the same set of stars. Current photometry seems to suggest that the WFI shows a positional effect when moving from the top to the bottom of individual chips. Preliminary results based on an independent data set collected with the MC suggest that this camera is only marginally affected by the same problem. To perform the absolute calibration we observed with each chip the same set of standard stars. The sample covers a wide color range and the accuracy both in the B and in the V-band appears to be of the order of a few hundredths of magnitude. Finally, we briefly outline the observing strategy to improve both relative and absolute calibrations of mosaic CCD cameras.

  5. Estimating Distances from Parallaxes

    NASA Astrophysics Data System (ADS)

    Bailer-Jones, Coryn A. L.

    2015-10-01

    Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that doing this is not trivial once the fractional parallax error is larger than about 20%, which will be the case for about 80% of stars in the Gaia catalog. Estimating distances is an inference problem in which the use of prior assumptions is unavoidable. I investigate the properties and performance of various priors and examine their implications. A supposed uninformative uniform prior in distance is shown to give very poor distance estimates (large bias and variance). Any prior with a sharp cut-off at some distance has similar problems. The choice of prior depends on the information one has available—and is willing to use—concerning, e.g., the survey and the Galaxy. I demonstrate that a simple prior which decreases asymptotically to zero at infinite distance has good performance, accommodates nonpositive parallaxes, and does not require a bias correction.

  6. Distance learning perspectives.

    PubMed

    Pandza, Haris; Masic, Izet

    2013-01-01

    The development of modern technology and the Internet has enabled the explosive growth of distance learning. distance learning is a process that is increasingly present in the world. This is the field of education focused on educating students who are not physically present in the traditional classrooms or student's campus. described as a process where the source of information is separated from the students in space and time. If there are situations that require the physical presence of students, such as when a student is required to physically attend the exam, this is called a hybrid form of distance learning. This technology is increasingly used worldwide. The Internet has become the main communication channel for the development of distance learning.

  7. Distance learning perspectives.

    PubMed

    Pandza, Haris; Masic, Izet

    2013-01-01

    The development of modern technology and the Internet has enabled the explosive growth of distance learning. distance learning is a process that is increasingly present in the world. This is the field of education focused on educating students who are not physically present in the traditional classrooms or student's campus. described as a process where the source of information is separated from the students in space and time. If there are situations that require the physical presence of students, such as when a student is required to physically attend the exam, this is called a hybrid form of distance learning. This technology is increasingly used worldwide. The Internet has become the main communication channel for the development of distance learning. PMID:24222934

  8. Technology and Distance Education.

    ERIC Educational Resources Information Center

    Pelton, J. N.; Bates, A. W.

    1991-01-01

    Two articles evaluate the impact of new transmission and information technologies on education: "Technology and Education--Friend or Foe?" (Pelton) and "Third Generation Distance Education: The Challenge of New Technology" (Bates). (SK)

  9. Absolute Radiometric Calibration of EUNIS-06

    NASA Technical Reports Server (NTRS)

    Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.

    2007-01-01

    The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to determine the instrument's absolute radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an absolute accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to determine the instrument's absolute spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.

  10. Clock time is absolute and universal

    NASA Astrophysics Data System (ADS)

    Shen, Xinhang

    2015-09-01

    A critical error is found in the Special Theory of Relativity (STR): mixing up the concepts of the STR abstract time of a reference frame and the displayed time of a physical clock, which leads to use the properties of the abstract time to predict time dilation on physical clocks and all other physical processes. Actually, a clock can never directly measure the abstract time, but can only record the result of a physical process during a period of the abstract time such as the number of cycles of oscillation which is the multiplication of the abstract time and the frequency of oscillation. After Lorentz Transformation, the abstract time of a reference frame expands by a factor gamma, but the frequency of a clock decreases by the same factor gamma, and the resulting multiplication i.e. the displayed time of a moving clock remains unchanged. That is, the displayed time of any physical clock is an invariant of Lorentz Transformation. The Lorentz invariance of the displayed times of clocks can further prove within the framework of STR our earth based standard physical time is absolute, universal and independent of inertial reference frames as confirmed by both the physical fact of the universal synchronization of clocks on the GPS satellites and clocks on the earth, and the theoretical existence of the absolute and universal Galilean time in STR which has proved that time dilation and space contraction are pure illusions of STR. The existence of the absolute and universal time in STR has directly denied that the reference frame dependent abstract time of STR is the physical time, and therefore, STR is wrong and all its predictions can never happen in the physical world.

  11. Achieving Climate Change Absolute Accuracy in Orbit

    NASA Technical Reports Server (NTRS)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  12. Absolute calibration of the Auger fluorescence detectors

    SciTech Connect

    Bauleo, P.; Brack, J.; Garrard, L.; Harton, J.; Knapik, R.; Meyhandan, R.; Rovero, A.C.; Tamashiro, A.; Warner, D.

    2005-07-01

    Absolute calibration of the Pierre Auger Observatory fluorescence detectors uses a light source at the telescope aperture. The technique accounts for the combined effects of all detector components in a single measurement. The calibrated 2.5 m diameter light source fills the aperture, providing uniform illumination to each pixel. The known flux from the light source and the response of the acquisition system give the required calibration for each pixel. In the lab, light source uniformity is studied using CCD images and the intensity is measured relative to NIST-calibrated photodiodes. Overall uncertainties are presently 12%, and are dominated by systematics.

  13. Absolute rate theories of epigenetic stability

    NASA Astrophysics Data System (ADS)

    Walczak, Aleksandra M.; Onuchic, José N.; Wolynes, Peter G.

    2005-12-01

    Spontaneous switching events in most characterized genetic switches are rare, resulting in extremely stable epigenetic properties. We show how simple arguments lead to theories of the rate of such events much like the absolute rate theory of chemical reactions corrected by a transmission factor. Both the probability of the rare cellular states that allow epigenetic escape and the transmission factor depend on the rates of DNA binding and unbinding events and on the rates of protein synthesis and degradation. Different mechanisms of escape from the stable attractors occur in the nonadiabatic, weakly adiabatic, and strictly adiabatic regimes, characterized by the relative values of those input rates. rate theory | stochastic gene expression | gene switches

  14. Characterization of the DARA solar absolute radiometer

    NASA Astrophysics Data System (ADS)

    Finsterle, W.; Suter, M.; Fehlmann, A.; Kopp, G.

    2011-12-01

    The Davos Absolute Radiometer (DARA) prototype is an Electrical Substitution Radiometer (ESR) which has been developed as a successor of the PMO6 type on future space missions and ground based TSI measurements. The DARA implements an improved thermal design of the cavity detector and heat sink assembly to minimize air-vacuum differences and to maximize thermal symmetry of measuring and compensating cavity. The DARA also employs an inverted viewing geometry to reduce internal stray light. We will report on the characterization and calibration experiments which were carried out at PMOD/WRC and LASP (TRF).

  15. Absolute Priority for a Vehicle in VANET

    NASA Astrophysics Data System (ADS)

    Shirani, Rostam; Hendessi, Faramarz; Montazeri, Mohammad Ali; Sheikh Zefreh, Mohammad

    In today's world, traffic jams waste hundreds of hours of our life. This causes many researchers try to resolve the problem with the idea of Intelligent Transportation System. For some applications like a travelling ambulance, it is important to reduce delay even for a second. In this paper, we propose a completely infrastructure-less approach for finding shortest path and controlling traffic light to provide absolute priority for an emergency vehicle. We use the idea of vehicular ad-hoc networking to reduce the imposed travelling time. Then, we simulate our proposed protocol and compare it with a centrally controlled traffic light system.

  16. Presence at a distance.

    PubMed

    Haddouk, Lise

    2015-01-01

    Nowadays in the context of the cyberculture, computer-mediated inter-subjective relationships are part of our everyday lives, in both the professional and personal spheres, and for all age groups. In the clinical field, many applications have been developed to facilitate the exchange of informations and mediate the relationship between patient and therapist. In psychology, more or less immersive technologies are used, to encourage the feeling of presence among the users, and to trigger certain psychological processes. In our research, we have explored the remote clinical interview through videoconferencing, with the development and utilisation of the iPSY platform, totally focused on this objective. In this context, we have considered the notion of intersubjectivity, despite the physical absence. This research is leading us today to envision the notions of distance and presence, and possibly to redefine them. Thus, can we still oppose physical distance to psychological distance? Can we still affirm that the physical absence does not permit a psychological co-presence in certain interactions, like this observed in video interviews? The results show that the psychological processes, activated in this context, are similar to those observed in "traditional" clinical consults between the patient and the therapist. However, certain specifics have led us to consider the concept of distance, here influenced by the framework, and to observe its effects. This distance could possibly constitute a therapeutic lever for some patients, notably for those who have difficulties establishing the right psychological distance in their relationships with others. According to these results, can "distance" still be opposed to "presence", or could it be re-defined? This also opens up questions on the more general concept of digital relationships, and the definition of their specificities. PMID:26799909

  17. Sentinel-2/MSI absolute calibration: first results

    NASA Astrophysics Data System (ADS)

    Lonjou, V.; Lachérade, S.; Fougnie, B.; Gamet, P.; Marcq, S.; Raynaud, J.-L.; Tremas, T.

    2015-10-01

    Sentinel-2 is an optical imaging mission devoted to the operational monitoring of land and coastal areas. It is developed in partnership between the European Commission and the European Space Agency. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. It will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). CNES is involved in the instrument commissioning in collaboration with ESA. This paper reviews all the techniques that will be used to insure an absolute calibration of the 13 spectral bands better than 5% (target 3%), and will present the first results if available. First, the nominal calibration technique, based on an on-board sun diffuser, is detailed. Then, we show how vicarious calibration methods based on acquisitions over natural targets (oceans, deserts, and Antarctica during winter) will be used to check and improve the accuracy of the absolute calibration coefficients. Finally, the verification scheme, exploiting photometer in-situ measurements over Lacrau plain, is described. A synthesis, including spectral coherence, inter-methods agreement and temporal evolution, will conclude the paper.

  18. Experimental results for absolute cylindrical wavefront testing

    NASA Astrophysics Data System (ADS)

    Reardon, Patrick J.; Alatawi, Ayshah

    2014-09-01

    Applications for Cylindrical and near-cylindrical surfaces are ever-increasing. However, fabrication of high quality cylindrical surfaces is limited by the difficulty of accurate and affordable metrology. Absolute testing of such surfaces represents a challenge to the optical testing community as cylindrical reference wavefronts are difficult to produce. In this paper, preliminary results for a new method of absolute testing of cylindrical wavefronts are presented. The method is based on the merging of the random ball test method with the fiber optic reference test. The random ball test assumes a large number of interferograms of a good quality sphere with errors that are statistically distributed such that the average of the errors goes to zero. The fiber optic reference test utilizes a specially processed optical fiber to provide a clean high quality reference wave from an incident line focus from the cylindrical wave under test. By taking measurements at different rotation and translations of the fiber, an analogous procedure can be employed to determine the quality of the converging cylindrical wavefront with high accuracy. This paper presents and discusses the results of recent tests of this method using a null optic formed by a COTS cylindrical lens and a free-form polished corrector element.

  19. Absolute Electron Extraction Efficiency of Liquid Xenon

    NASA Astrophysics Data System (ADS)

    Kamdin, Katayun; Mizrachi, Eli; Morad, James; Sorensen, Peter

    2016-03-01

    Dual phase liquid/gas xenon time projection chambers (TPCs) currently set the world's most sensitive limits on weakly interacting massive particles (WIMPs), a favored dark matter candidate. These detectors rely on extracting electrons from liquid xenon into gaseous xenon, where they produce proportional scintillation. The proportional scintillation from the extracted electrons serves to internally amplify the WIMP signal; even a single extracted electron is detectable. Credible dark matter searches can proceed with electron extraction efficiency (EEE) lower than 100%. However, electrons systematically left at the liquid/gas boundary are a concern. Possible effects include spontaneous single or multi-electron proportional scintillation signals in the gas, or charging of the liquid/gas interface or detector materials. Understanding EEE is consequently a serious concern for this class of rare event search detectors. Previous EEE measurements have mostly been relative, not absolute, assuming efficiency plateaus at 100%. I will present an absolute EEE measurement with a small liquid/gas xenon TPC test bed located at Lawrence Berkeley National Laboratory.

  20. Why to compare absolute numbers of mitochondria.

    PubMed

    Schmitt, Sabine; Schulz, Sabine; Schropp, Eva-Maria; Eberhagen, Carola; Simmons, Alisha; Beisker, Wolfgang; Aichler, Michaela; Zischka, Hans

    2014-11-01

    Prompted by pronounced structural differences between rat liver and rat hepatocellular carcinoma mitochondria, we suspected these mitochondrial populations to differ massively in their molecular composition. Aiming to reveal these mitochondrial differences, we came across the issue on how to normalize such comparisons and decided to focus on the absolute number of mitochondria. To this end, fluorescently stained mitochondria were quantified by flow cytometry. For rat liver mitochondria, this approach resulted in mitochondrial protein contents comparable to earlier reports using alternative methods. We determined similar protein contents for rat liver, heart and kidney mitochondria. In contrast, however, lower protein contents were determined for rat brain mitochondria and for mitochondria from the rat hepatocellular carcinoma cell line McA 7777. This result challenges mitochondrial comparisons that rely on equal protein amounts as a typical normalization method. Exemplarily, we therefore compared the activity and susceptibility toward inhibition of complex II of rat liver and hepatocellular carcinoma mitochondria and obtained significant discrepancies by either normalizing to protein amount or to absolute mitochondrial number. Importantly, the latter normalization, in contrast to the former, demonstrated a lower complex II activity and higher susceptibility toward inhibition in hepatocellular carcinoma mitochondria compared to liver mitochondria. These findings demonstrate that solely normalizing to protein amount may obscure essential molecular differences between mitochondrial populations.

  1. Relational versus absolute representation in categorization.

    PubMed

    Edwards, Darren J; Pothos, Emmanuel M; Perlman, Amotz

    2012-01-01

    This study explores relational-like and absolute-like representations in categorization. Although there is much evidence that categorization processes can involve information about both the particular physical properties of studied instances and abstract (relational) properties, there has been little work on the factors that lead to one kind of representation as opposed to the other. We tested 370 participants in 6 experiments, in which participants had to classify new items into predefined artificial categories. In 4 experiments, we observed a predominantly relational-like mode of classification, and in 2 experiments we observed a shift toward an absolute-like mode of classification. These results suggest 3 factors that promote a relational-like mode of classification: fewer items per group, more training groups, and the presence of a time delay. Overall, we propose that less information about the distributional properties of a category or weaker memory traces for the category exemplars (induced, e.g., by having smaller categories or a time delay) can encourage relational-like categorization.

  2. Transient absolute robustness in stochastic biochemical networks.

    PubMed

    Enciso, German A

    2016-08-01

    Absolute robustness allows biochemical networks to sustain a consistent steady-state output in the face of protein concentration variability from cell to cell. This property is structural and can be determined from the topology of the network alone regardless of rate parameters. An important question regarding these systems is the effect of discrete biochemical noise in the dynamical behaviour. In this paper, a variable freezing technique is developed to show that under mild hypotheses the corresponding stochastic system has a transiently robust behaviour. Specifically, after finite time the distribution of the output approximates a Poisson distribution, centred around the deterministic mean. The approximation becomes increasingly accurate, and it holds for increasingly long finite times, as the total protein concentrations grow to infinity. In particular, the stochastic system retains a transient, absolutely robust behaviour corresponding to the deterministic case. This result contrasts with the long-term dynamics of the stochastic system, which eventually must undergo an extinction event that eliminates robustness and is completely different from the deterministic dynamics. The transiently robust behaviour may be sufficient to carry out many forms of robust signal transduction and cellular decision-making in cellular organisms. PMID:27581485

  3. A Conceptual Approach to Absolute Value Equations and Inequalities

    ERIC Educational Resources Information Center

    Ellis, Mark W.; Bryson, Janet L.

    2011-01-01

    The absolute value learning objective in high school mathematics requires students to solve far more complex absolute value equations and inequalities. When absolute value problems become more complex, students often do not have sufficient conceptual understanding to make any sense of what is happening mathematically. The authors suggest that the…

  4. Using, Seeing, Feeling, and Doing Absolute Value for Deeper Understanding

    ERIC Educational Resources Information Center

    Ponce, Gregorio A.

    2008-01-01

    Using sticky notes and number lines, a hands-on activity is shared that anchors initial student thinking about absolute value. The initial point of reference should help students successfully evaluate numeric problems involving absolute value. They should also be able to solve absolute value equations and inequalities that are typically found in…

  5. Long distance entanglement distribution

    NASA Astrophysics Data System (ADS)

    Broadfoot, Stuart Graham

    Developments in the interdisciplinary field of quantum information open up previously impossible abilities in the realms of information processing and communication. Quantum entanglement has emerged as one property of quantum systems that acts as a resource for quantum information processing and, in particular, enables teleportation and secure cryptography. Therefore, the creation of entangled resources is of key importance for the application of these technologies. Despite a great deal of research the efficient creation of entanglement over long distances is limited by inevitable noise. This problem can be overcome by creating entanglement between nodes in a network and then performing operations to distribute the entanglement over a long distance. This thesis contributes to the field of entanglement distribution within such quantum networks. Entanglement distribution has been extensively studied for one-dimensional networks resulting in "quantum repeater" protocols. However, little work has been done on higher dimensional networks. In these networks a fundamentally different scaling, called "long distance entanglement distribution", can appear between the resources and the distance separating the systems to be entangled. I reveal protocols that enable long distance entanglement distribution for quantum networks composed of mixed state and give a few limitations to the capabilities of entanglement distribution. To aid in the implementation of all entanglement distribution protocols I finish by introducing a new system, composed of an optical nanofibre coupled to a carbon nanotube, that may enable new forms of photo-detectors and quantum memories.

  6. Stereoscopic distance perception

    NASA Technical Reports Server (NTRS)

    Foley, John M.

    1989-01-01

    Limited cue, open-loop tasks in which a human observer indicates distances or relations among distances are discussed. By open-loop tasks, it is meant tasks in which the observer gets no feedback as to the accuracy of the responses. What happens when cues are added and when the loop is closed are considered. The implications of this research for the effectiveness of visual displays is discussed. Errors in visual distance tasks do not necessarily mean that the percept is in error. The error could arise in transformations that intervene between the percept and the response. It is argued that the percept is in error. It is also argued that there exist post-perceptual transformations that may contribute to the error or be modified by feedback to correct for the error.

  7. Emerging distance degree programs.

    PubMed

    Birnbaum, D; Greenhalgh, T

    2000-01-01

    The variation in program focus and style is examined in this column, which also identifies resources for evaluation. The integration of Web-based or other distance modality materials to conventional courses, and the expansion of traditional universities to include a virtual campus, should proceed with caution and systematic evaluation. It is an evolution that offers both rewards and pitfalls, but requires more rigorous examination. This article provides information about pedagogical issues and additional distance-education master's degree programs. Some are new, while others are established.

  8. The Absolute Radiometric Calibration of Space - Sensors.

    NASA Astrophysics Data System (ADS)

    Holm, Ronald Gene

    1987-09-01

    The need for absolute radiometric calibration of space-based sensors will continue to increase as new generations of space sensors are developed. A reflectance -based in-flight calibration procedure is used to determine the radiance reaching the entrance pupil of the sensor. This procedure uses ground-based measurements coupled with a radiative transfer code to characterize the effects the atmosphere has on the signal reaching the sensor. The computed radiance is compared to the digital count output of the sensor associated with the image of a test site. This provides an update to the preflight calibration of the system and a check on the on-board internal calibrator. This calibration procedure was used to perform a series of five calibrations of the Landsat-5 Thematic Mapper (TM). For the 12 measurements made in TM bands 1-3, the RMS variation from the mean as a percentage of the mean is (+OR-) 1.9%, and for measurements in the IR, TM bands 4,5, and 7, the value is (+OR-) 3.4%. The RMS variation for all 23 measurements is (+OR-) 2.8%. The absolute calibration techniques were put to another test with a series of three calibration of the SPOT-1 High Resolution Visible, (HRV), sensors. The ratio, HRV-2/HRV-1, of absolute calibration coefficients compared very well with ratios of histogrammed data obtained when the cameras simultaneously imaged the same ground site. Bands PA, B1 and B3 agreed to within 3%, while band B2 showed a 7% difference. The procedure for performing a satellite calibration was then used to demonstrate how a calibrated satellite sensor can be used to quantitatively evaluate surface reflectance over a wide range of surface features. Predicted reflectance factors were compared to values obtained from aircraft -based radiometer data. This procedure was applied on four dates with two different surface conditions per date. A strong correlation, R('2) = .996, was shown between reflectance values determined from satellite imagery and low-flying aircraft

  9. Absolute position total internal reflection microscopy with an optical tweezer

    PubMed Central

    Liu, Lulu; Woolf, Alexander; Rodriguez, Alejandro W.; Capasso, Federico

    2014-01-01

    A noninvasive, in situ calibration method for total internal reflection microscopy (TIRM) based on optical tweezing is presented, which greatly expands the capabilities of this technique. We show that by making only simple modifications to the basic TIRM sensing setup and procedure, a probe particle’s absolute position relative to a dielectric interface may be known with better than 10 nm precision out to a distance greater than 1 μm from the surface. This represents an approximate 10× improvement in error and 3× improvement in measurement range over conventional TIRM methods. The technique’s advantage is in the direct measurement of the probe particle’s scattering intensity vs. height profile in situ, rather than relying on assumptions, inexact system analogs, or detailed knowledge of system parameters for calibration. To demonstrate the improved versatility of the TIRM method in terms of tunability, precision, and range, we show our results for the hindered near-wall diffusion coefficient for a spherical dielectric particle. PMID:25512542

  10. Use of Absolute and Comparative Performance Feedback in Absolute and Comparative Judgments and Decisions

    ERIC Educational Resources Information Center

    Moore, Don A.; Klein, William M. P.

    2008-01-01

    Which matters more--beliefs about absolute ability or ability relative to others? This study set out to compare the effects of such beliefs on satisfaction with performance, self-evaluations, and bets on future performance. In Experiment 1, undergraduate participants were told they had answered 20% correct, 80% correct, or were not given their…

  11. Absolute radiometric calibration of the CCRS SAR

    NASA Astrophysics Data System (ADS)

    Ulander, Lars M. H.; Hawkins, Robert K.; Livingstone, Charles E.; Lukowski, Tom I.

    1991-11-01

    Determining the radar scattering coefficients from SAR (synthetic aperture radar) image data requires absolute radiometric calibration of the SAR system. The authors describe an internal calibration methodology for the airborne Canada Centre for Remote Sensing (CCRS) SAR system, based on radar theory, a detailed model of the radar system, and measurements of system parameters. The methodology is verified by analyzing external calibration data acquired over a 6-month period in 1988 by the C-band radar using HH polarization. The results indicate that the overall error is +/- 0.8 dB (1-sigma) for incidence angles +/- 20 deg from antenna boresight. The dominant error contributions are due to the antenna radome and uncertainties in the elevation angle relative to the antenna boresight.

  12. Absolute calibration of ultraviolet filter photometry

    NASA Technical Reports Server (NTRS)

    Bless, R. C.; Fairchild, T.; Code, A. D.

    1972-01-01

    The essential features of the calibration procedure can be divided into three parts. First, the shape of the bandpass of each photometer was determined by measuring the transmissions of the individual optical components and also by measuring the response of the photometer as a whole. Secondly, each photometer was placed in the essentially-collimated synchrotron radiation bundle maintained at a constant intensity level, and the output signal was determined from about 100 points on the objective. Finally, two or three points on the objective were illuminated by synchrotron radiation at several different intensity levels covering the dynamic range of the photometers. The output signals were placed on an absolute basis by the electron counting technique described earlier.

  13. Absolute measurements of fast neutrons using yttrium

    SciTech Connect

    Roshan, M. V.; Springham, S. V.; Rawat, R. S.; Lee, P.; Krishnan, M.

    2010-08-15

    Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be f{sub n}{approx}4.1x10{sup -4} with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 10{sup 8} neutrons per discharge.

  14. Absolute geostrophic currents in global tropical oceans

    NASA Astrophysics Data System (ADS)

    Yang, Lina; Yuan, Dongliang

    2016-11-01

    A set of absolute geostrophic current (AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profiles in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin (except the North Indian Ocean, where the circulation is dominated by monsoons). The identified non-Sverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom (JEBAR) and mesoscale eddy nonlinearity.

  15. Absolute Measurement of Electron Cloud Density

    SciTech Connect

    Covo, M K; Molvik, A W; Cohen, R H; Friedman, A; Seidl, P A; Logan, G; Bieniosek, F; Baca, D; Vay, J; Orlando, E; Vujic, J L

    2007-06-21

    Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 {micro}s duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL.

  16. Absolute calibration of remote sensing instruments

    NASA Astrophysics Data System (ADS)

    Biggar, S. F.; Bruegge, C. J.; Capron, B. A.; Castle, K. R.; Dinguirard, M. C.; Holm, R. G.; Lingg, L. J.; Mao, Y.; Palmer, J. M.; Phillips, A. L.

    1985-12-01

    Source-based and detector-based methods for the absolute radiometric calibration of a broadband field radiometer are described. Using such a radiometer, calibrated by both methods, the calibration of the integrating sphere used in the preflight calibration of the Thematic Mapper was redetermined. The results are presented. The in-flight calibration of space remote sensing instruments is discussed. A method which uses the results of ground-based reflectance and atmospheric measurements as input to a radiative transfer code to predict the radiance at the instrument is described. A calibrated, helicopter-mounted radiometer is used to determine the radiance levels at intermediate altitudes to check the code predictions. Results of such measurements for the calibration of the Thematic Mapper on Landsat 5 and an analysis that shows the value of such measurements are described.

  17. Absolute radiometric calibration of the Thematic Mapper

    NASA Technical Reports Server (NTRS)

    Slater, P. N.; Biggar, S. F.; Holm, R. G.; Jackson, R. D.; Mao, Y.

    1986-01-01

    Calibration data for the solar reflective bands of the Landsat-5 TM obtained from five in-flight absolute radiometric calibrations from July 1984-November 1985 at White Sands, New Mexico are presented and analyzed. Ground reflectance and atmospheric data were utilized to predict the spectral radiance at the entrance pupil of the TM and the average number of digital counts in each TM band. The calibration of each of the TM solar reflective bands was calculated in terms of average digital counts/unit spectral radiance for each band. It is observed that for the 12 reflectance-based measurements the rms variation from the means as a percentage of the mean is + or - 1.9 percent; for the 11 measurements in the IR bands, it is + or - 3.4 percent; and the rms variation for all 23 measurements is + or - 2.8 percent.

  18. Swarm's Absolute Scalar Magnetometer metrological performances

    NASA Astrophysics Data System (ADS)

    Leger, J.; Fratter, I.; Bertrand, F.; Jager, T.; Morales, S.

    2012-12-01

    The Absolute Scalar Magnetometer (ASM) has been developed for the ESA Earth Observation Swarm mission, planned for launch in November 2012. As its Overhauser magnetometers forerunners flown on Oersted and Champ satellites, it will deliver high resolution scalar measurements for the in-flight calibration of the Vector Field Magnetometer manufactured by the Danish Technical University. Latest results of the ground tests carried out to fully characterize all parameters that may affect its accuracy, both at instrument and satellite level, will be presented. In addition to its baseline function, the ASM can be operated either at a much higher sampling rate (burst mode at 250 Hz) or in a dual mode where it also delivers vector field measurements as a by-product. The calibration procedure and the relevant vector performances will be discussed.

  19. MAGSAT: Vector magnetometer absolute sensor alignment determination

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.

    1981-01-01

    A procedure is described for accurately determining the absolute alignment of the magnetic axes of a triaxial magnetometer sensor with respect to an external, fixed, reference coordinate system. The method does not require that the magnetic field vector orientation, as generated by a triaxial calibration coil system, be known to better than a few degrees from its true position, and minimizes the number of positions through which a sensor assembly must be rotated to obtain a solution. Computer simulations show that accuracies of better than 0.4 seconds of arc can be achieved under typical test conditions associated with existing magnetic test facilities. The basic approach is similar in nature to that presented by McPherron and Snare (1978) except that only three sensor positions are required and the system of equations to be solved is considerably simplified. Applications of the method to the case of the MAGSAT Vector Magnetometer are presented and the problems encountered discussed.

  20. THE ABSOLUTE MAGNITUDES OF RED HORIZONTAL BRANCH STARS IN THE ugriz SYSTEM

    SciTech Connect

    Chen, Y. Q.; Zhao, G.; Zhao, J. K.

    2009-09-10

    Based on photometric data of the central parts of eight globular clusters and one open cluster presented by An and his collaborators, we select red horizontal branch (RHB) stars in the (g - r){sub 0}-g {sub 0} diagram and make a statistical study of the distributions of their colors and absolute magnitudes in the SDSS ugriz system. Meanwhile, absolute magnitudes in the Johnson VRI system are calculated through the translation formulae between gri and VRI in the literature. The calibrations of absolute magnitude as functions of metallicity and age are established by linear regressions of the data. It is found that metallicity coefficients in these calibrations decrease, while age coefficients increase, from the blue u filter to the red z filter. The calibration of M{sub i} = 0.06[Fe/H] + 0.040t + 0.03 has the smallest scatter of 0.04 mag, and thus i is the best filter in the ugriz system when RHB stars are used for distance indicators. The comparison of the M{sub I} calibration from our data with that from red clump stars indicates that the previous suggestion that the I filter is better than the V filter in distance determination may not be true because of its significant dependence on age.

  1. Copyright and Distance Education.

    ERIC Educational Resources Information Center

    MacKnight, Carol B.

    2000-01-01

    Reports on three workshops offering copyright education for library and computer services staff and administrators. Topics covered included: copyright (e.g., the Copyright Act of 1976 and classroom teaching); digital distance education issues (application of fair use to on-line teaching); and compliance (under the Digital Millennium Copyright…

  2. Prospect of Distance Learning

    ERIC Educational Resources Information Center

    Rahman, Monsurur; Karim, Reza; Byramjee, Framarz

    2015-01-01

    Many educational institutions in the United States are currently offering programs through distance learning, and that trend is rising. In almost all spheres of education a developing country like Bangladesh needs to make available the expertise of the most qualified faculty to her distant people. But the fundamental question remains as to whether…

  3. Accreditation of Distance Learning

    ERIC Educational Resources Information Center

    Demirel, Ergün

    2016-01-01

    The higher education institutes aspire to gain reputation of quality having accreditation from internationally recognized awarding bodies. The accreditation leads and provides quality assurance for education. Although distance learning becomes a significant part of the education system in the 21st century, there is still a common opinion that the…

  4. Advances in Distance Learning.

    ERIC Educational Resources Information Center

    1999

    This document contains three symposium papers on advances in distance learning. "The Adoption of Computer Technology and Telecommunications: A Case Study" (Larry M. Dooley, Teri Metcalf, Ann Martinez) reports on a study of the possible applications of two theoretical models (Rogers' Diffusion of Innovations model and the Concerns-Based Adoption…

  5. Rapport in Distance Education

    ERIC Educational Resources Information Center

    Murphy, Elizabeth; Rodriguez-Manzanares, Maria A.

    2012-01-01

    Rapport has been recognized as important in learning in general but little is known about its importance in distance education (DE). The study we report on in this paper provides insights into the importance of rapport in DE as well as challenges to and indicators of rapport-building in DE. The study relied on interviews with 42 Canadian…

  6. Distance Learning Programming.

    ERIC Educational Resources Information Center

    Lucero, Jesus Ricardo; And Others

    This resource guide for distance learning information, courses, and programming covers: (1) audiographics programming by the Pennsylvania Teleteaching Project; (2) cable programming, including the Cable Alliance for Education's Cable in the Classroom projects, Consumer News and Business Channel, Nostalgia Television, PENNARAMA Channel, Silent…

  7. Distance Education Policy Framework.

    ERIC Educational Resources Information Center

    Oregon State System of Higher Education, Eugene.

    This description of the policy framework for Oregon's distance education program gives an overview of the progress to date, outlines five areas in which policy must be developed, and identifies a number of priorities among those areas. Progress is reported in the following areas: several initiatives that incorporate new telecommunications and…

  8. Going the Distance

    ERIC Educational Resources Information Center

    Barack, Lauren

    2005-01-01

    Sixty years ago, distance education probably involved a pen, paper, and secretarial classes conducted via snail mail. Today, students in ever-increasing numbers are more likely to link to the Internet to learn how to conjugate French verbs or dissect frogs in Advanced Placement courses, according to a new landmark study from the U. S. Department…

  9. Time-distance helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, T. L., Jr.; Jefferies, S. M.; Harvey, J. W.; Pomerantz, M. A.

    1993-01-01

    It is shown here that it is possible to extract time-distance information from temporal cross-correlations of the intensity fluctuation on the solar surface. This approach opens the way for seismic studies of local solar phenomena such subsurface inhomogeneities near sunspots and should help to refine global models of the internal velocity stratification in the sun.

  10. Misconceptions of Astronomical Distances

    ERIC Educational Resources Information Center

    Miller, Brian W.; Brewer, William F.

    2010-01-01

    Previous empirical studies using multiple-choice procedures have suggested that there are misconceptions about the scale of astronomical distances. The present study provides a quantitative estimate of the nature of this misconception among US university students by asking them, in an open-ended response format, to make estimates of the distances…

  11. Technology & Distance Learning Survey.

    ERIC Educational Resources Information Center

    Florida Human Resources Development, Inc., Gainesville.

    A survey was conducted to assess the current state of technology and distance learning awareness and usage in Florida's adult education and community-based programs. Data were gathered through a survey of 350 adult practitioners, literacy providers, community-based organizations and libraries throughout the state (125 responses [36 percent return…

  12. Encyclopedia of Distance Learning

    ERIC Educational Resources Information Center

    Howard, Caroline, Ed.; Boettecher, Judith, Ed.; Justice, Lorraine, Ed.; Schenk, Karen, Ed.; Rogers, Patricia, Ed.; Berg, Gary, Ed.

    2005-01-01

    The innovations in computer and communications technologies combined with on-going needs to deliver educational programs to students regardless of their physical locations, have lead to the innovation of distance education programs and technologies. To keep up with recent developments in both areas of technologies and techniques related to…

  13. Faculty and Distance Education.

    ERIC Educational Resources Information Center

    Saba, Farhad, Ed.

    1998-01-01

    Outlines the role of faculty and issues that need to be addressed early on if large-scale distance education is going to be successful. Discusses academic freedom; intellectual property; training; compensation; and royalties and revenue sharing. Notes the importance of active involvement by faculty in shaping the university of the future. (AEF)

  14. On Markov Earth Mover’s Distance

    PubMed Central

    Wei, Jie

    2015-01-01

    In statistics, pattern recognition and signal processing, it is of utmost importance to have an effective and efficient distance to measure the similarity between two distributions and sequences. In statistics this is referred to as goodness-of-fit problem. Two leading goodness of fit methods are chi-square and Kolmogorov–Smirnov distances. The strictly localized nature of these two measures hinders their practical utilities in patterns and signals where the sample size is usually small. In view of this problem Rubner and colleagues developed the earth mover’s distance (EMD) to allow for cross-bin moves in evaluating the distance between two patterns, which find a broad spectrum of applications. EMD-L1 was later proposed to reduce the time complexity of EMD from super-cubic by one order of magnitude by exploiting the special L1 metric. EMD-hat was developed to turn the global EMD to a localized one by discarding long-distance earth movements. In this work, we introduce a Markov EMD (MEMD) by treating the source and destination nodes absolutely symmetrically. In MEMD, like hat-EMD, the earth is only moved locally as dictated by the degree d of neighborhood system. Nodes that cannot be matched locally is handled by dummy source and destination nodes. By use of this localized network structure, a greedy algorithm that is linear to the degree d and number of nodes is then developed to evaluate the MEMD. Empirical studies on the use of MEMD on deterministic and statistical synthetic sequences and SIFT-based image retrieval suggested encouraging performances. PMID:25983362

  15. Effect of Geographic Distance on Distance Education: An Empirical Study

    ERIC Educational Resources Information Center

    Luo, Heng; Robinson, Anthony C.; Detwiler, Jim

    2014-01-01

    This study investigates the effect of geographic distance on students' distance learning experience with the aim to provide tentative answers to a fundamental question--does geographic distance matter in distance education? Using educational outcome data collected from an online master's program in Geographic Information Systems, this…

  16. Distance Training as Part of a Distance Consulting Solution.

    ERIC Educational Resources Information Center

    Fulantelli, Giovanni; Chiazzese, Giuseppe; Allegra, Mario

    "Distance Training" models, when integrated in a more complex framework, such as a "Distance Consulting" model, present specific features and impose a revision of the strategies commonly adopted in distance training experiences. This paper reports on the distance training strategies adopted in a European funded project aimed at defining and…

  17. Comb-referenced laser distance interferometer for industrial nanotechnology

    NASA Astrophysics Data System (ADS)

    Jang, Yoon-Soo; Wang, Guochao; Hyun, Sangwon; Kang, Hyun Jay; Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-08-01

    A prototype laser distance interferometer is demonstrated by incorporating the frequency comb of a femtosecond laser for mass-production of optoelectronic devices such as flat panel displays and solar cell devices. This comb-referenced interferometer uses four different wavelengths simultaneously to enable absolute distance measurement with the capability of comprehensive evaluation of the measurement stability and uncertainty. The measurement result reveals that the stability reaches 3.4 nm for a 3.8 m distance at 1.0 s averaging, which further reduces to 0.57 nm at 100 s averaging with a fractional stability of 1.5 × 10‑10. The uncertainty is estimated to be in a 10‑8 level when distance is measured in air due to the inevitable ambiguity in estimating the refractive index, but it can be enhanced to a 10‑10 level in vacuum.

  18. Comb-referenced laser distance interferometer for industrial nanotechnology.

    PubMed

    Jang, Yoon-Soo; Wang, Guochao; Hyun, Sangwon; Kang, Hyun Jay; Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-08-25

    A prototype laser distance interferometer is demonstrated by incorporating the frequency comb of a femtosecond laser for mass-production of optoelectronic devices such as flat panel displays and solar cell devices. This comb-referenced interferometer uses four different wavelengths simultaneously to enable absolute distance measurement with the capability of comprehensive evaluation of the measurement stability and uncertainty. The measurement result reveals that the stability reaches 3.4 nm for a 3.8 m distance at 1.0 s averaging, which further reduces to 0.57 nm at 100 s averaging with a fractional stability of 1.5 × 10(-10). The uncertainty is estimated to be in a 10(-8) level when distance is measured in air due to the inevitable ambiguity in estimating the refractive index, but it can be enhanced to a 10(-10) level in vacuum.

  19. Pacing and Performance in Competitive Middle-Distance Speed Skating

    ERIC Educational Resources Information Center

    Muehlbauer, Thomas; Schindler, Christian; Panzer, Stefan

    2010-01-01

    Data from speed skating during World Cup 1,500-m middle-distance races were analyzed to (a) determine the time/velocity distribution during the race and (b) assess the impact of time spent in several race sectors on performance outcome. Absolute and relative sector times for the first 300 m (S1) and the following three 400-m laps (S2-S4) and their…

  20. Perception of Egocentric Distance during Gravitational Changes in Parabolic Flight.

    PubMed

    Clément, Gilles; Loureiro, Nuno; Sousa, Duarte; Zandvliet, Andre

    2016-01-01

    We explored the effect of gravity on the perceived representation of the absolute distance of objects to the observers within the range from 1.5-6 m. Experiments were performed on board the CNES Airbus Zero-G during parabolic flights eliciting repeated exposures to short periods of microgravity (0 g), hypergravity (1.8 g), and normal gravity (1 g). Two methods for obtaining estimates of perceived egocentric distance were used: verbal reports and visually directed motion toward a memorized visual target. For the latter method, because normal walking is not possible in 0 g, blindfolded subjects translated toward the visual target by pulling on a rope with their arms. The results showed that distance estimates using both verbal reports and blind pulling were significantly different between normal gravity, microgravity, and hypergravity. Compared to the 1 g measurements, the estimates of perceived distance using blind pulling were shorter for all distances in 1.8 g, whereas in 0 g they were longer for distances up to 4 m and shorter for distances beyond. These findings suggest that gravity plays a role in both the sensorimotor system and the perceptual/cognitive system for estimating egocentric distance. PMID:27463106

  1. Perception of Egocentric Distance during Gravitational Changes in Parabolic Flight.

    PubMed

    Clément, Gilles; Loureiro, Nuno; Sousa, Duarte; Zandvliet, Andre

    2016-01-01

    We explored the effect of gravity on the perceived representation of the absolute distance of objects to the observers within the range from 1.5-6 m. Experiments were performed on board the CNES Airbus Zero-G during parabolic flights eliciting repeated exposures to short periods of microgravity (0 g), hypergravity (1.8 g), and normal gravity (1 g). Two methods for obtaining estimates of perceived egocentric distance were used: verbal reports and visually directed motion toward a memorized visual target. For the latter method, because normal walking is not possible in 0 g, blindfolded subjects translated toward the visual target by pulling on a rope with their arms. The results showed that distance estimates using both verbal reports and blind pulling were significantly different between normal gravity, microgravity, and hypergravity. Compared to the 1 g measurements, the estimates of perceived distance using blind pulling were shorter for all distances in 1.8 g, whereas in 0 g they were longer for distances up to 4 m and shorter for distances beyond. These findings suggest that gravity plays a role in both the sensorimotor system and the perceptual/cognitive system for estimating egocentric distance.

  2. Perception of Egocentric Distance during Gravitational Changes in Parabolic Flight

    PubMed Central

    Clément, Gilles; Loureiro, Nuno; Sousa, Duarte; Zandvliet, Andre

    2016-01-01

    We explored the effect of gravity on the perceived representation of the absolute distance of objects to the observers within the range from 1.5–6 m. Experiments were performed on board the CNES Airbus Zero-G during parabolic flights eliciting repeated exposures to short periods of microgravity (0 g), hypergravity (1.8 g), and normal gravity (1 g). Two methods for obtaining estimates of perceived egocentric distance were used: verbal reports and visually directed motion toward a memorized visual target. For the latter method, because normal walking is not possible in 0 g, blindfolded subjects translated toward the visual target by pulling on a rope with their arms. The results showed that distance estimates using both verbal reports and blind pulling were significantly different between normal gravity, microgravity, and hypergravity. Compared to the 1 g measurements, the estimates of perceived distance using blind pulling were shorter for all distances in 1.8 g, whereas in 0 g they were longer for distances up to 4 m and shorter for distances beyond. These findings suggest that gravity plays a role in both the sensorimotor system and the perceptual/cognitive system for estimating egocentric distance. PMID:27463106

  3. Consensus Document on Intermittent Claudication from the Central European Vascular Forum (C.E.V.F.)-3rd revision (2013) with the sharing of the Mediterranean League of Angiology and Vascular Surgery, and the North Africa and Middle East Chapter of International Union of Angiology.

    PubMed

    Andreozzi, G M; Kalodiki, E; L Gašpar, L; Martini, R; Minar, E; Angelides, N; Nicolaides, A N; Novo, S; Visonà, A; Prior, M; Arosio, E; Hussein, E A; Poredos, P; Antignani, P L; Avram, R; Roztocil, K; Stvrtinova, V; Kozak, M; Vacula, I

    2014-08-01

    This paper is the review of the Consensus Document on Intermittent Claudication of the Central European Vascular Forum (CEVF), published in 2008, and and shared with the North Africa and Middle East Chapter of International Union of Angiology and the Mediterranean League of Angiology and Vascular Surgery. The Document presents suggestions for general practitioners and vascular specialists for more precise and appropriate management of PAD, particularly of intermittent claudication, and underlines the investigations that should be required by GPs and what the GP should expect from the vascular specialist (angiologist, vascular surgeon). The idea of the Faculty is to produce a short document, which is an easy reference in daily clinical practice, both for the GPs and vascular specialists.

  4. On the absence of absolutely continuous spectra for Schroedinger operators on radial tree graphs

    SciTech Connect

    Exner, Pavel; Lipovsky, Jiri

    2010-12-15

    The subject of the paper is Schroedinger operators on tree graphs which are radial, having the branching number b{sub n} at all the vertices at the distance t{sub n} from the root. We consider a family of coupling conditions at the vertices characterized by (b{sub n}-1){sup 2}+4 real parameters. We prove that if the graph is sparse so that there is a subsequence of {l_brace}t{sub n+1}-t{sub n{r_brace}} growing to infinity, in the absence of the potential the absolutely continuous spectrum is empty for a large subset of these vertex couplings, but on the the other hand, there are cases when the spectrum of such a Schroedinger operator can be purely absolutely continuous.

  5. Geodetic distance measuring apparatus

    NASA Technical Reports Server (NTRS)

    Abshire, J. B. (Inventor)

    1983-01-01

    A mode locked laser system including a laser device and its peripheral components is utilized for deriving two mutually phase locked optical wavelength signals and one phase locked microwave CW signal which respectively traverse the same distance measurement path. Preferably the optical signals are comprised of pulse type signals. Phase comparison of the two optical wavelength pulse signals is used to provide a measure of the dry air density while phase comparison of one of the optical wavelength pulse signals and the microwave CW signal is used to provide a measure of the wet or water vapor density of the air. From these measurements is computed in means of the distance to be measured corrected for the atmospheric dry and water vapor densities in the measurement path.

  6. Distance mitigates perceived threat.

    PubMed

    Stamps, Arthur E

    2011-12-01

    It has previously been shown that distance mitigates the extent to which visual cues convey perceived threat. It was hypothesized that the visual cues of eye contact, sex, facial expression, and posture would all convey threat. It was further hypothesized that the effects of visual cues on the perception of threat would decrease with distance, but the extent of those decreases was unknown. In the present study, participants were exposed to images of people situated in a physical venue. The images were created to exhibit combinations of the levels of the four visual cues (yes or no for eye contact, male or female for sex, hostile or benign for facial expression, and hostile or benign for posture). Participants were given an opportunity to record how threatening the images of the people seemed to be. The results supported all a priori hypotheses regarding the effects of the visual cues. The results also generated estimates of the distances at which those visual cues ceased to convey threat.

  7. Evaluating linguistic distance measures

    NASA Astrophysics Data System (ADS)

    Wichmann, Søren; Holman, Eric W.; Bakker, Dik; Brown, Cecil H.

    2010-09-01

    In Ref. [13], Petroni and Serva discuss the use of Levenshtein distances (LD) between words referring to the same concepts as a tool for establishing overall distances among languages which can then subsequently be used to derive phylogenies. The authors modify the raw LD by dividing the LD by the length of the longer of the two words compared, to produce what could be called LDN (normalized LD). Other scholars [7,8] have used a further modification, where they divide the LDN by the average LDN among words not referring to the same concept. This produces what could be called LDND. The authors of Ref. [13] question whether LDND is a more adequate measure of distance than LDN. Here we show empirically that LDND is the better measure in the situation where the languages compared have not already been shown, by other, more traditional methods of comparative linguistics, to be related. If automated language classification is to be used as a tool independent of traditional methods then the further modification is necessary.

  8. Nutrition for distance events.

    PubMed

    Burke, Louise M; Millet, Gregoire; Tarnopolsky, Mark A

    2007-01-01

    The goal of training is to prepare the distance athlete to perform at his or her best during major competitions. Whatever the event, nutrition plays a major role in the achievement of various factors that will see a runner or walker take the starting line in the best possible form. Everyday eating patterns must supply fuel and nutrients needed to optimize their performance during training sessions and to recover quickly afterwards. Carbohydrate and fluid intake before, during, and after a workout may help to reduce fatigue and enhance performance. Recovery eating should also consider issues for adaptation and the immune system that may involve intakes of protein and some micronutrients. Race preparation strategies should include preparation of adequate fuel stores, including carbohydrate loading for prolonged events such as the marathon or 50-km walk. Fluid and carbohydrate intake during races lasting an hour or more should also be considered. Sports foods and supplements of value to distance athletes include sports drinks and liquid meal supplements to allow nutrition goals to be achieved when normal foods are not practical. While caffeine is an ergogenic aid of possible value to distance athletes, most other supplements are of minimal benefit. PMID:18049981

  9. On the absolute alignment of GONG images

    NASA Astrophysics Data System (ADS)

    Toner, C. G.

    2001-01-01

    In order to combine data from the six instruments in the GONG network the alignment of all of the images must be known to a fairly high precision (~0°.1 for GONG Classic and ~0°.01 for GONG+). The relative orientation is obtained using the angular cross-correlation method described by (Toner & Harvey, 1998). To obtain the absolute orientation the Project periodically records a day of drift scans, where the image of the Sun is allowed to drift across the CCD repeatedly throughout the day. These data are then analyzed to deduce the direction of Terrestrial East-West as a function of hour angle (i.e., time) for that instrument. The transit of Mercury on Nov. 15, 1999, which was recorded by three of the GONG instruments, provided an independent check on the current alignment procedures. Here we present a comparison of the alignment of GONG images as deduced from both drift scans and the Mercury transit for two GONG sites: Tucson (GONG+ camera) and Mauna Loa (GONG Classic camera). The agreement is within ~0°.01 for both cameras, however, the scatter is substantially larger for GONG Classic: ~0°.03 compared to ~0°.01 for GONG+.

  10. Climate Absolute Radiance and Refractivity Observatory (CLARREO)

    NASA Technical Reports Server (NTRS)

    Leckey, John P.

    2015-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) is a mission, led and developed by NASA, that will measure a variety of climate variables with an unprecedented accuracy to quantify and attribute climate change. CLARREO consists of three separate instruments: an infrared (IR) spectrometer, a reflected solar (RS) spectrometer, and a radio occultation (RO) instrument. The mission will contain orbiting radiometers with sufficient accuracy, including on orbit verification, to calibrate other space-based instrumentation, increasing their respective accuracy by as much as an order of magnitude. The IR spectrometer is a Fourier Transform spectrometer (FTS) working in the 5 to 50 microns wavelength region with a goal of 0.1 K (k = 3) accuracy. The FTS will achieve this accuracy using phase change cells to verify thermistor accuracy and heated halos to verify blackbody emissivity, both on orbit. The RS spectrometer will measure the reflectance of the atmosphere in the 0.32 to 2.3 microns wavelength region with an accuracy of 0.3% (k = 2). The status of the instrumentation packages and potential mission options will be presented.

  11. Absolute flux measurements for swift atoms

    NASA Technical Reports Server (NTRS)

    Fink, M.; Kohl, D. A.; Keto, J. W.; Antoniewicz, P.

    1987-01-01

    While a torsion balance in vacuum can easily measure the momentum transfer from a gas beam impinging on a surface attached to the balance, this measurement depends on the accommodation coefficients of the atoms with the surface and the distribution of the recoil. A torsion balance is described for making absolute flux measurements independent of recoil effects. The torsion balance is a conventional taut suspension wire design and the Young modulus of the wire determines the relationship between the displacement and the applied torque. A compensating magnetic field is applied to maintain zero displacement and provide critical damping. The unique feature is to couple the impinging gas beam to the torsion balance via a Wood's horn, i.e., a thin wall tube with a gradual 90 deg bend. Just as light is trapped in a Wood's horn by specular reflection from the curved surfaces, the gas beam diffuses through the tube. Instead of trapping the beam, the end of the tube is open so that the atoms exit the tube at 90 deg to their original direction. Therefore, all of the forward momentum of the gas beam is transferred to the torsion balance independent of the angle of reflection from the surfaces inside the tube.

  12. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    SciTech Connect

    Jian-Zhou Zhu and Gregory W. Hammett

    2011-01-10

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, "On some statistical properties of hydrodynamical and magnetohydrodynamical fields," Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: A finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N + 1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  13. Issues in Absolute Spectral Radiometric Calibration: Intercomparison of Eight Sources

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Kindel, Bruce; Pilewskie, Peter

    1998-01-01

    The application of atmospheric models to AVIRIS and other spectral imaging data to derive surface reflectance requires that the sensor output be calibrated to absolute radiance. Uncertainties in absolute calibration are to be expected, and claims of 92% accuracy have been published. Measurements of accurate surface albedos and cloud absorption to be used in radiative balance calculations depend critically on knowing the absolute spectral-radiometric response of the sensor. The Earth Observing System project is implementing a rigorous program of absolute radiometric calibration for all optical sensors. Since a number of imaging instruments that provide output in terms of absolute radiance are calibrated at different sites, it is important to determine the errors that can be expected among calibration sites. Another question exists about the errors in the absolute knowledge of the exoatmospheric spectral solar irradiance.

  14. Absolute nuclear material assay using count distribution (LAMBDA) space

    SciTech Connect

    Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.

    2015-12-01

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  15. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  16. Antifungal activity of tuberose absolute and some of its constituents.

    PubMed

    Nidiry, Eugene Sebastian J; Babu, C S Bujji

    2005-05-01

    The antifungal activity of the absolute of tuberose (Polianthes tuberosa ) and some of its constituents were evaluated against the mycelial growth of Colletotrichum gloeosporioides on potato-dextrose-agar medium. Tuberose absolute showed only mild activity at a concentration of 500 mg/L. However, three constituents present in the absolute, namely geraniol, indole and methyl anthranilate exhibited significant activity showing total inhibition of the mycelial growth at this concentration.

  17. On the Error Sources in Absolute Individual Antenna Calibrations

    NASA Astrophysics Data System (ADS)

    Aerts, Wim; Baire, Quentin; Bilich, Andria; Bruyninx, Carine; Legrand, Juliette

    2013-04-01

    The two main methods for antenna calibration currently in use, are anechoic chamber measurements on the one hand and outdoor robot calibration on the other hand. Both techniques differ completely in approach, setup and data processing. Consequently, the error sources for both techniques are totally different as well. Except for the (near field) multi path error, caused by the antenna positioning device, that alters results for both calibration methods. But not necessarily with the same order of magnitude. Literature states a (maximum deviation) repeatability for robot calibration of choke ring antennas of 0.5 mm on L1 and 1 mm on L2 [1]. For anechoic chamber calibration, a value of 1.5 mm on L2 for a resistive ground plane antenna can be found in [2]. Repeatability however masks systematic errors linked with the calibration technique. Hence, comparing an individual calibration obtained with a robot to a calibration of the same antenna in an anechoic chamber, may result in differences that surpass these repeatability thresholds. This was the case at least for all six choke ring antennas studied. The order of magnitude of the differences moreover corresponded well to the values given for a LEIAT504GG in [3]. For some error sources, such as the GNSS receiver measurement noise or the VNA measurement noise, estimates can be obtained from manufacturer specifications in data sheets. For other error sources, such as the finite distance between transmit and receive antenna, or the limited attenuation of reflections on wall absorber, back-of-the-envelope calculations can be made to estimate their order of magnitude. For the error due to (near field) multi path this is harder to do, if not impossible. The more because this strongly depends on the antenna type and its mount. Unfortunately it is, again, this (near field) multi path influence that might void the calibration once the antenna is installed at the station. Hence it can be concluded that at present, due to (near

  18. Distance to Dark Bodies

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Using the unique orbit of NASA's Spitzer Space Telescope and a depth-perceiving trick called parallax, astronomers have determined the distance to an invisible Milky Way object called OGLE-2005-SMC-001. This artist's concept illustrates how this trick works: different views from both Spitzer and telescopes on Earth are combined to give depth perception.

    Our Milky Way galaxy is heavier than it looks, and scientists use the term 'dark matter' to describe all the 'heavy stuff' in the universe that seems to be present but invisible to our telescopes. While much of this dark matter is likely made up of exotic materials, different from the ordinary particles that make up the world around us, some may consist of dark celestial bodies -- like planets, black holes, or failed stars -- that do not produce light or are too faint to detect from Earth. OGLE-2005-SMC-001 is one of these dark celestial bodies.

    Although astronomers cannot see a dark body, they can sense its presence from the way light acts around it. When a dark body like OGLE-2005-SMC-001 passes in front of a bright star, its gravity causes the background starlight to bend and brighten, a process called gravitational microlensing. When the observing telescope, dark body, and star system are closely aligned, the microlensing event reaches maximum, or peak, brightness.

    A team of astronomers first sensed OGLE-2005-SMC-001's presence when it passed in front of a star in a neighboring satellite galaxy called the Small Magellanic Cloud. In this artist's rendering, the satellite galaxy is depicted as the fuzzy structure sitting to the left of Earth. Once they detected this microlensing event, the scientists used Spitzer and the principle of parallax to figure out its distance. Humans naturally use parallax to determine distance. Each eye sees the distance of an object differently. The brain takes each eye's perspective and instantaneously calculates how far away the object is.

    To determine OGLE

  19. Advanced hierarchical distance sampling

    USGS Publications Warehouse

    Royle, Andy

    2016-01-01

    In this chapter, we cover a number of important extensions of the basic hierarchical distance-sampling (HDS) framework from Chapter 8. First, we discuss the inclusion of “individual covariates,” such as group size, in the HDS model. This is important in many surveys where animals form natural groups that are the primary observation unit, with the size of the group expected to have some influence on detectability. We also discuss HDS integrated with time-removal and double-observer or capture-recapture sampling. These “combined protocols” can be formulated as HDS models with individual covariates, and thus they have a commonality with HDS models involving group structure (group size being just another individual covariate). We cover several varieties of open-population HDS models that accommodate population dynamics. On one end of the spectrum, we cover models that allow replicate distance sampling surveys within a year, which estimate abundance relative to availability and temporary emigration through time. We consider a robust design version of that model. We then consider models with explicit dynamics based on the Dail and Madsen (2011) model and the work of Sollmann et al. (2015). The final major theme of this chapter is relatively newly developed spatial distance sampling models that accommodate explicit models describing the spatial distribution of individuals known as Point Process models. We provide novel formulations of spatial DS and HDS models in this chapter, including implementations of those models in the unmarked package using a hack of the pcount function for N-mixture models.

  20. Absolute Plate Velocities from Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Kreemer, Corné; Zheng, Lin; Gordon, Richard

    2015-04-01

    The orientation of seismic anisotropy inferred beneath plate interiors may provide a means to estimate the motions of the plate relative to the sub-asthenospheric mantle. Here we analyze two global sets of shear-wave splitting data, that of Kreemer [2009] and an updated and expanded data set, to estimate plate motions and to better understand the dispersion of the data, correlations in the errors, and their relation to plate speed. We also explore the effect of using geologically current plate velocities (i.e., the MORVEL set of angular velocities [DeMets et al. 2010]) compared with geodetically current plate velocities (i.e., the GSRM v1.2 angular velocities [Kreemer et al. 2014]). We demonstrate that the errors in plate motion azimuths inferred from shear-wave splitting beneath any one tectonic plate are correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. The SKS-MORVEL absolute plate angular velocities (based on the Kreemer [2009] data set) are determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25±0.11° Ma-1 (95% confidence limits) right-handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ=19.2° ) differs insignificantly from that for continental lithosphere (σ=21.6° ). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ=7.4° ) than for continental

  1. Evaluation of the Absolute Regional Temperature Potential

    NASA Technical Reports Server (NTRS)

    Shindell, D. T.

    2012-01-01

    The Absolute Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP presented here gives the time-dependent temperature response in four latitude bands (90-28degS, 28degS-28degN, 28-60degN and 60-90degN) as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate model to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate models. These ARTP results are in good accord with the actual responses in those models. Nearly all ARTP estimates fall within +/-20%of the actual responses, though there are some exceptions for 90-28degS and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the +/-20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39-45% and 9-39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer scale than global metrics without requiring use of a full climate model.

  2. Absolute Radiometric Calibration of KOMPSAT-3A

    NASA Astrophysics Data System (ADS)

    Ahn, H. Y.; Shin, D. Y.; Kim, J. S.; Seo, D. C.; Choi, C. U.

    2016-06-01

    This paper presents a vicarious radiometric calibration of the Korea Multi-Purpose Satellite-3A (KOMPSAT-3A) performed by the Korea Aerospace Research Institute (KARI) and the Pukyong National University Remote Sensing Group (PKNU RSG) in 2015.The primary stages of this study are summarized as follows: (1) A field campaign to determine radiometric calibrated target fields was undertaken in Mongolia and South Korea. Surface reflectance data obtained in the campaign were input to a radiative transfer code that predicted at-sensor radiance. Through this process, equations and parameters were derived for the KOMPSAT-3A sensor to enable the conversion of calibrated DN to physical units, such as at-sensor radiance or TOA reflectance. (2) To validate the absolute calibration coefficients for the KOMPSAT-3A sensor, we performed a radiometric validation with a comparison of KOMPSAT-3A and Landsat-8 TOA reflectance using one of the six PICS (Libya 4). Correlations between top-of-atmosphere (TOA) radiances and the spectral band responses of the KOMPSAT-3A sensors at the Zuunmod, Mongolia and Goheung, South Korea sites were significant for multispectral bands. The average difference in TOA reflectance between KOMPSAT-3A and Landsat-8 image over the Libya 4, Libya site in the red-green-blue (RGB) region was under 3%, whereas in the NIR band, the TOA reflectance of KOMPSAT-3A was lower than the that of Landsat-8 due to the difference in the band passes of two sensors. The KOMPSAT-3Aensor includes a band pass near 940 nm that can be strongly absorbed by water vapor and therefore displayed low reflectance. Toovercome this, we need to undertake a detailed analysis using rescale methods, such as the spectral bandwidth adjustment factor.

  3. Orion Absolute Navigation System Progress and Challenge

    NASA Technical Reports Server (NTRS)

    Holt, Greg N.; D'Souza, Christopher

    2012-01-01

    The absolute navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

  4. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  5. Absolute homogeneity test of Kelantan catchment precipitation series

    NASA Astrophysics Data System (ADS)

    Ros, Faizah Che; Tosaka, Hiroyuki; Sasaki, Kenji; Sidek, Lariyah Mohd; Basri, Hidayah

    2015-05-01

    Along the Kelantan River in north east of Malaysia Peninsular, there are several areas often damaged by flood during north-east monsoon season every year. It is vital to predict the expected behavior of precipitation and river runoff for reducing flood damages of the area under rapid urbanization and future planning. Nevertheless, the accuracy and reliability of any hydrological and climate studies vary based on the quality of the data used. The factors causing variations on these data are the method of gauging and data collection, stations environment, station relocation and the reliability of the measurement tool affect the homogenous precipitation records. Hence in this study, homogeneity of long precipitation data series is checked via the absolute homogeneity test consisting of four methods namely Pettitt test, standard normal homogeneity test (SNHT), Buishand range test and Von Neumann ratio test. For homogeneity test, the annual rainfall amount from the daily precipitation records at stations located in Kelantan operated by Department of Irrigation and Drainage Malaysia were considered in this study. The missing values were completed using the correlation and regression and inverse distance method. The data network consists of 103 precipitation gauging stations where 31 points are inactive, 6 gauging stations had missing precipitation values more than five years in a row and 16 stations have records less than twenty years. So total of 50 stations gauging stations were evaluated in this analysis. With the application of the mentioned methods and further graphical analysis, inhomogeneity was detected at 4 stations and 46 stations are found to be homogeneous.

  6. Time-Distance Helioseismology

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L., Jr.

    2010-01-01

    Time-distance helioseismology is a method of ambient noise imaging using the solar oscillations. The basic realization that led to time-distance helioseismology was that the temporal cross correlation of the signals at two 'surface' (or photospheric) locations should show a feature at the time lag corresponding to the subsurface travel time between the locations. The temporal cross correlation, as a function of the location separation, is the Fourier transform of the spatio-temporal power spectrum of the solar oscillations, a commonly used function in helioseismology. It is therefore likely the characteristic ridge structure of the correlation function had been seen before without appreciation of its significance. Travel times are measured from the cross correlations. The times are sensitive to a number of important subsurface solar phenomena. These include sound speed variations, flows, and magnetic fields. There has been much interesting progress in the 17 years since the first paper on this subject (Duvall et al., Nature, 1993, 362, 430-432). This progress will be reviewed in this paper.

  7. Distance collaborations with industry

    SciTech Connect

    Peskin, A.; Swyler, K.

    1998-06-01

    The college industry relationship has been identified as a key policy issue in Engineering Education. Collaborations between academic institutions and the industrial sector have a long history and a bright future. For Engineering and Engineering Technology programs in particular, industry has played a crucial role in many areas including advisement, financial support, and practical training of both faculty and students. Among the most important and intimate interactions are collaborative projects and formal cooperative education arrangements. Most recently, such collaborations have taken on a new dimension, as advances in technology have made possible meaningful technical collaboration at a distance. There are several obvious technology areas that have contributed significantly to this trend. Foremost is the ubiquitous presence of the Internet. Perhaps almost as important are advances in computer based imaging. Because visual images offer a compelling user experience, it affords greater knowledge transfer efficiency than other modes of delivery. Furthermore, the quality of the image appears to have a strongly correlated effect on insight. A good visualization facility offers both a means for communication and a shared information space for the subjects, which are among the essential features of both peer collaboration and distance learning.

  8. Mid-infrared absolute spectral responsivity scale based on an absolute cryogenic radiometer and an optical parametric oscillator laser

    NASA Astrophysics Data System (ADS)

    Zhao, Kun; Shi, Xueshun; Chen, Haidong; Liu, Yulong; Liu, Changming; Chen, Kunfeng; Li, Ligong; Gan, Haiyong; Ma, Chong

    2016-06-01

    We are reporting on a laser-based absolute spectral responsivity scale in the mid-infrared spectral range. By using a mid-infrared tunable optical parametric oscillator as the laser source, the absolute responsivity scale has been established by calibrating thin-film thermopile detectors against an absolute cryogenic radiometer. The thin-film thermopile detectors can be then used as transfer standard detectors. The extended uncertainty of the absolute spectral responsivity measurement has been analyzed to be 0.58%–0.68% (k  =  2).

  9. Mid-infrared absolute spectral responsivity scale based on an absolute cryogenic radiometer and an optical parametric oscillator laser

    NASA Astrophysics Data System (ADS)

    Zhao, Kun; Shi, Xueshun; Chen, Haidong; Liu, Yulong; Liu, Changming; Chen, Kunfeng; Li, Ligong; Gan, Haiyong; Ma, Chong

    2016-06-01

    We are reporting on a laser-based absolute spectral responsivity scale in the mid-infrared spectral range. By using a mid-infrared tunable optical parametric oscillator as the laser source, the absolute responsivity scale has been established by calibrating thin-film thermopile detectors against an absolute cryogenic radiometer. The thin-film thermopile detectors can be then used as transfer standard detectors. The extended uncertainty of the absolute spectral responsivity measurement has been analyzed to be 0.58%-0.68% (k  =  2).

  10. Double threshold ultrasonic distance measurement technique and its application

    NASA Astrophysics Data System (ADS)

    Li, Weihua; Chen, Qiang; Wu, Jiangtao

    2014-04-01

    The double threshold method realized by hardware circuits and high performance timing chip TDC-GP21 was successfully adapted to solve the key problem of ultrasonic distance measurement, the accurate time-of-flight (TOF) measurement of ultrasonic wave. Compared with other techniques of TOF measurement, the double threshold method presented in this work can suppress noise in the received signal, and achieve a time resolution of around 22 ps and real-time. This method is easy to realize and pertains the advantage of low cost. To compensate temperature and pressure deviations, a temperature measurement module of 10 mK in precision as well as a pressure measurement module of 0.01% in accuracy was developed. The system designed in this work can be exactly used as a two paths ultrasonic gas flowmeter without any adjustment of the hardware circuit. The double threshold method was further corroborated using experiment results of both the ultrasonic distance measurement and ultrasonic gas flow measurement. In distance measurement, the maximum absolute deviation and the maximum relative error are 0.69 mm and 0.28%, respectively, for a target distance range of 100-600 mm. In flow measurement, the maximum absolute deviation and the worst repeatability are 1.16% and 0.65% for a flow in the range of 50-700 m3/h.

  11. Double threshold ultrasonic distance measurement technique and its application.

    PubMed

    Li, Weihua; Chen, Qiang; Wu, Jiangtao

    2014-04-01

    The double threshold method realized by hardware circuits and high performance timing chip TDC-GP21 was successfully adapted to solve the key problem of ultrasonic distance measurement, the accurate time-of-flight (TOF) measurement of ultrasonic wave. Compared with other techniques of TOF measurement, the double threshold method presented in this work can suppress noise in the received signal, and achieve a time resolution of around 22 ps and real-time. This method is easy to realize and pertains the advantage of low cost. To compensate temperature and pressure deviations, a temperature measurement module of 10 mK in precision as well as a pressure measurement module of 0.01% in accuracy was developed. The system designed in this work can be exactly used as a two paths ultrasonic gas flowmeter without any adjustment of the hardware circuit. The double threshold method was further corroborated using experiment results of both the ultrasonic distance measurement and ultrasonic gas flow measurement. In distance measurement, the maximum absolute deviation and the maximum relative error are 0.69 mm and 0.28%, respectively, for a target distance range of 100-600 mm. In flow measurement, the maximum absolute deviation and the worst repeatability are 1.16% and 0.65% for a flow in the range of 50-700 m(3)/h. PMID:24784646

  12. Novalis' Poetic Uncertainty: A "Bildung" with the Absolute

    ERIC Educational Resources Information Center

    Mika, Carl

    2016-01-01

    Novalis, the Early German Romantic poet and philosopher, had at the core of his work a mysterious depiction of the "absolute." The absolute is Novalis' name for a substance that defies precise knowledge yet calls for a tentative and sensitive speculation. How one asserts a truth, represents an object, and sets about encountering things…

  13. Absolute Pitch in Infant Auditory Learning: Evidence for Developmental Reorganization.

    ERIC Educational Resources Information Center

    Saffran, Jenny R.; Griepentrog, Gregory J.

    2001-01-01

    Two experiments examined 8-month-olds' use of absolute and relative pitch cues in a tone-sequence statistical learning task. Results suggest that, given unsegmented stimuli that do not conform to rules of musical composition, infants are more likely to track patterns of absolute pitches than of relative pitches. A third experiment found that adult…

  14. Supplementary and Enrichment Series: Absolute Value. Teachers' Commentary. SP-25.

    ERIC Educational Resources Information Center

    Bridgess, M. Philbrick, Ed.

    This is one in a series of manuals for teachers using SMSG high school supplementary materials. The pamphlet includes commentaries on the sections of the student's booklet, answers to the exercises, and sample test questions. Topics covered include addition and multiplication in terms of absolute value, graphs of absolute value in the Cartesian…

  15. Supplementary and Enrichment Series: Absolute Value. SP-24.

    ERIC Educational Resources Information Center

    Bridgess, M. Philbrick, Ed.

    This is one in a series of SMSG supplementary and enrichment pamphlets for high school students. This series is designed to make material for the study of topics of special interest to students readily accessible in classroom quantity. Topics covered include absolute value, addition and multiplication in terms of absolute value, graphs of absolute…

  16. Absolute dimensions of unevolved O type close binaries

    SciTech Connect

    Doom, C.; de Loore, C.

    1984-03-15

    A method is presented to derive the absolute dimensions of early-type detached binaries by combining the observed parameters with results of evolutionary computations. The method is used to obtain the absolute dimensions of nine close binaries. We find that most systems have an initial masss ratio near 1.

  17. Absolute Humidity and the Seasonality of Influenza (Invited)

    NASA Astrophysics Data System (ADS)

    Shaman, J. L.; Pitzer, V.; Viboud, C.; Grenfell, B.; Goldstein, E.; Lipsitch, M.

    2010-12-01

    Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent re-analysis of laboratory experiments indicates that absolute humidity strongly modulates the airborne survival and transmission of the influenza virus. Here we show that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low absolute humidity levels during the prior weeks. We then use an epidemiological model, in which observed absolute humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The model results indicate that direct modulation of influenza transmissibility by absolute humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that absolute humidity drives seasonal variations of influenza transmission in temperate regions. In addition, we show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in absolute humidity, are consistent with the general timing of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions. Indeed, absolute humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the timing of pandemic influenza outbreaks is controlled by a combination of absolute humidity conditions, levels of susceptibility and changes in population mixing and contact rates.

  18. Determination of Absolute Zero Using a Computer-Based Laboratory

    ERIC Educational Resources Information Center

    Amrani, D.

    2007-01-01

    We present a simple computer-based laboratory experiment for evaluating absolute zero in degrees Celsius, which can be performed in college and undergraduate physical sciences laboratory courses. With a computer, absolute zero apparatus can help demonstrators or students to observe the relationship between temperature and pressure and use…

  19. Absolute radiometric calibration of advanced remote sensing systems

    NASA Technical Reports Server (NTRS)

    Slater, P. N.

    1982-01-01

    The distinction between the uses of relative and absolute spectroradiometric calibration of remote sensing systems is discussed. The advantages of detector-based absolute calibration are described, and the categories of relative and absolute system calibrations are listed. The limitations and problems associated with three common methods used for the absolute calibration of remote sensing systems are addressed. Two methods are proposed for the in-flight absolute calibration of advanced multispectral linear array systems. One makes use of a sun-illuminated panel in front of the sensor, the radiance of which is monitored by a spectrally flat pyroelectric radiometer. The other uses a large, uniform, high-radiance reference ground surface. The ground and atmospheric measurements required as input to a radiative transfer program to predict the radiance level at the entrance pupil of the orbital sensor are discussed, and the ground instrumentation is described.

  20. Spatial Homogeneity and Redshift--Distance Laws

    NASA Astrophysics Data System (ADS)

    Nicoll, J. F.; Segal, I. E.

    1982-06-01

    Spatial homogeneity in the radial direction of low-redshift galaxies is subjected to Kafka-Schmidt V/Vm tests using well-documented samples. Homogeneity is consistent with the assumption of the Lundmark (quadratic redshift-distance) law, but large deviations from homogeneity are implied by the assumption of the Hubble (linear redshift-distance) law. These deviations are similar to what would be expected on the basis of the Lundmark law. Luminosity functions are obtained for each law by a nonparametric statistically optimal method that removes the observational cutoff bias in complete samples. Although the Hubble law correlation of absolute magnitude with redshift is reduced considerably by elimination of the bias, computer simulations show that its bias-free value is nevertheless at a satistically quite significant level, indicating the self-inconsistency of the law. The corresponding Lundmark law correlations are quite satisfactory satistically. The regression of redshift on magnitude also involves radial spatial homogeneity and, according to R. Soneira, has slope determining the redshift-magnitude exponent independently of the luminosity function. We have, however, rigorously proved the material dependence of the regression on this function and here exemplify our treatment by using the bias-free functions indicated, with results consistent with the foregoing argument.

  1. Algebraic distance on graphs.

    SciTech Connect

    Chen, J.; Safro, I.

    2011-01-01

    Measuring the connection strength between a pair of vertices in a graph is one of the most important concerns in many graph applications. Simple measures such as edge weights may not be sufficient for capturing the effects associated with short paths of lengths greater than one. In this paper, we consider an iterative process that smooths an associated value for nearby vertices, and we present a measure of the local connection strength (called the algebraic distance; see [D. Ron, I. Safro, and A. Brandt, Multiscale Model. Simul., 9 (2011), pp. 407-423]) based on this process. The proposed measure is attractive in that the process is simple, linear, and easily parallelized. An analysis of the convergence property of the process reveals that the local neighborhoods play an important role in determining the connectivity between vertices. We demonstrate the practical effectiveness of the proposed measure through several combinatorial optimization problems on graphs and hypergraphs.

  2. Continuing Education for Distance Librarians

    ERIC Educational Resources Information Center

    Cassner, Mary; Adams, Kate E.

    2012-01-01

    Distance librarians as engaged professionals work in a complex environment of changes in technologies, user expectations, and institutional goals. They strive to keep current with skills and competencies to support distance learners. This article provides a selection of continuing education opportunities for distance librarians, and is relevant…

  3. Interactive Distance Learning in Connecticut.

    ERIC Educational Resources Information Center

    Pietras, Jesse John; Murphy, Robert J.

    This paper provides an overview of distance learning activities in Connecticut and addresses the feasibility of such activities. Distance education programs have evolved from the one dimensional electronic mail systems to the use of sophisticated digital fiber networks. The Middlesex Distance Learning Consortium has developed a long-range plan to…

  4. Teleteaching Distance Education. Final Report.

    ERIC Educational Resources Information Center

    Mansfield Univ., PA. Rural Services Inst.

    This study investigated the need for distance learning in Pennsylvania's rural schools, examined types of distance learning programs and technology currently being used, and identified factors that could enhance or inhibit the use of distance learning in rural schools. Data collection included (1) a literature search, (2) surveys administered to…

  5. The Evolution of Distance Education.

    ERIC Educational Resources Information Center

    Lever-Duffy, Judy

    1999-01-01

    Provides an overview of distance-education technologies. Discusses synchronous and asynchronous distance-delivery approaches, and the extent to which they offer students the opportunity to interact with other students and faculty. Suggests elements that comprise an ideal delivery system, and offers some views on the future of distance education.…

  6. Reconsidering Moore's Transactional Distance Theory

    ERIC Educational Resources Information Center

    Giossos, Yiannis; Koutsouba, Maria; Lionarakis, Antonis; Skavantzos, Kosmas

    2009-01-01

    One of the core theories of distance education is Michael Graham Moore's "Theory of Transactional Distance" that provides the broad framework of the pedagogy of distance education and allows the generation of almost infinite number of hypotheses for research. However, the review of the existing studies relating to the theory showed the use of a…

  7. Verification of 235U mass content in nuclear fuel plates by an absolute method

    NASA Astrophysics Data System (ADS)

    El-Gammal, W.

    2007-01-01

    Nuclear Safeguards is referred to a verification System by which a State can control all nuclear materials (NM) and nuclear activities under its authority. An effective and efficient Safeguards System must include a system of measurements with capabilities sufficient to verify such NM. Measurements of NM using absolute methods could eliminate the dependency on NM Standards, which are necessary for other relative or semi-absolute methods. In this work, an absolute method has been investigated to verify the 235U mass content in nuclear fuel plates of Material Testing Reactor (MTR) type. The most intense gamma-ray signature at 185.7 keV emitted after α-decay of the 235U nuclei was employed in the method. The measuring system (an HPGe-spectrometer) was mathematically calibrated for efficiency using the general Monte Carlo transport code MCNP-4B. The calibration results and the measured net count rate were used to estimate the 235U mass content in fuel plates at different detector-to-fuel plate distances. Two sets of fuel plates, containing natural and low enriched uranium, were measured at the Fuel Fabrication Facility. Average accuracies for the estimated 235U masses of about 2.62% and 0.3% are obtained for the fuel plates containing natural and low enriched uranium; respectively, with a precision of about 3%.

  8. DISTANCES TO DARK CLOUDS: COMPARING EXTINCTION DISTANCES TO MASER PARALLAX DISTANCES

    SciTech Connect

    Foster, Jonathan B.; Jackson, James M.; Stead, Joseph J.; Hoare, Melvin G.; Benjamin, Robert A. E-mail: jackson@bu.edu E-mail: mgh@ast.leeds.ac.uk

    2012-06-01

    We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near-infrared (Two Micron All Sky Survey and UKIRT Infrared Deep Sky Survey) surveys. Very long baseline interferometry parallax measurements of masers around massive young stars provide the most direct and bias-free measurement of the distance to these dark clouds. We compare the extinction distance estimates to these maser parallax distances. We also compare these distances to kinematic distances, including recent re-calibrations of the Galactic rotation curve. The extinction distance methods agree with the maser parallax distances (within the errors) between 66% and 100% of the time (depending on method and input survey) and between 85% and 100% of the time outside of the crowded Galactic center. Although the sample size is small, extinction distance methods reproduce maser parallax distances better than kinematic distances; furthermore, extinction distance methods do not suffer from the kinematic distance ambiguity. This validation gives us confidence that these extinction methods may be extended to additional dark clouds where maser parallaxes are not available.

  9. The visual surface brightness relation and the absolute magnitudes of RR Lyrae stars. I - Theory

    NASA Technical Reports Server (NTRS)

    Manduca, A.; Bell, R. A.

    1981-01-01

    A theoretical relation analogous to the Barnes-Evans relation between stellar surface brightness and V-R color is derived which is applicable to the temperatures and gravities appropriate to RR Lyrae stars. Values of the visual surface brightness and V-R colors are calculated for model stellar atmospheres with effective temperatures between 6000 and 8000 K, log surface gravities from 2.2 to 3.5, and A/H anbundance ratios from -0.5 to -3.0. The resulting relation is found to be in reasonable agreement with the empirical relation of Barnes, Evans and Moffet (1978), with, however, small sensitivities to gravity and metal abundance. The relation may be used to derive stellar angular diameters from (V,R) photometry and to derive radii, distances, and absolute magnitudes for variable stars when combined with a radial velocity curve. The accuracies of the radii and distances (within 10%) and absolute magnitudes (within 0.25 magnitudes) compare favorably with those of the Baade-Wesselink method currently in use.

  10. Distance sampling for Sonoran Desert tortoises

    USGS Publications Warehouse

    Swann, D.E.; Averill-Murray, R. C.; Schwalbe, C.R.

    2002-01-01

    We used line transects and distance sampling in combination with radiotelemetry to estimate density of a desert tortoise (Gopherus agassizii) population in the Rincon Mountains near Tucson, Arizona, USA, as part of a long-term study evaluating the impact of urban development on tortoises. During 2000, 34 1-km transects were each sampled twice in the 368.5-ha study area. We observed 46 tortoises with midline carapace lengths ???150 mm (subadults and adults) plus 7 juveniles on transects. For subadults and adults, the encounter rate was 0.63 tortoises/km, and the mean proportion of tortoises observable during radiotelemetry, conducted concurrently with transect sampling, was 82%. Corrected mean density based on line transects and radiotelemetry was 0.523 tortoises/ha (CV = 22.99, 95% CI = 0.29-0.79), and absolute abundance in the study area was estimated to be 193 (CV = 23.0%, CI = 107-291). Using the 2 independent coverages of transects as separate samples, the Lincoln-Petersen mark-recapture estimator produced an abundance estimate of 224 subadult and adult tortoises (CV = 53.9%, CI = 72-440). Transects measured on the ground over uneven topography resulted in 3% smaller estimates of density when compared to analysis with transect lengths determined from coordinates plotted on a map. Distance sampling appears to be a feasible method of estimating density of Sonoran Desert populations of the desert tortoise, but transect lengths should be based on mapped rather than measured distances to prevent biases caused by uneven topography.

  11. Absolute and relative reliability of lumbar interspinous process ultrasound imaging measurements

    PubMed Central

    Tozawa, Ryosuke; Katoh, Munenori; Aramaki, Hidefumi; Kawasaki, Tsubasa; Nishikawa, Yuichi; Kumamoto, Tsuneo; Fujinawa, Osamu

    2016-01-01

    [Purpose] The intra- and inter-examiner reliabilities of lumbar interspinous process distances measured by ultrasound imaging were examined. [Subjects and Methods] The subjects were 10 males who had no history of orthopedic diseases or dysfunctions. Ten lumbar interspinous images from 360 images captured from 10 subjects were selected. The 10 images were measured by nine examiners. The lumbar interspinous process distance measurements were performed five times by each examiner. In addition, four of the nine examiners measured the distances again after 4 days for test-retest analysis. In statistical analysis, the intraclass correlation coefficient was used to investigate relative reliability, and Bland-Altman analysis was used to investigate absolute reliability. [Results] The intraclass correlation coefficients (1, 1) for intra-examiner reliability ranged from 0.985 to 0.998. For inter-rater reliability, the intraclass correlation coefficient (2, 1) was 0.969. The intraclass correlation coefficients (1, 2) for test-retest reliability ranged from 0.991 to 0.999. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The results indicate that ultrasound measurements of interspinous process distance are highly reliable even when measured only once by a single person.

  12. Absolute and relative reliability of lumbar interspinous process ultrasound imaging measurements.

    PubMed

    Tozawa, Ryosuke; Katoh, Munenori; Aramaki, Hidefumi; Kawasaki, Tsubasa; Nishikawa, Yuichi; Kumamoto, Tsuneo; Fujinawa, Osamu

    2016-08-01

    [Purpose] The intra- and inter-examiner reliabilities of lumbar interspinous process distances measured by ultrasound imaging were examined. [Subjects and Methods] The subjects were 10 males who had no history of orthopedic diseases or dysfunctions. Ten lumbar interspinous images from 360 images captured from 10 subjects were selected. The 10 images were measured by nine examiners. The lumbar interspinous process distance measurements were performed five times by each examiner. In addition, four of the nine examiners measured the distances again after 4 days for test-retest analysis. In statistical analysis, the intraclass correlation coefficient was used to investigate relative reliability, and Bland-Altman analysis was used to investigate absolute reliability. [Results] The intraclass correlation coefficients (1, 1) for intra-examiner reliability ranged from 0.985 to 0.998. For inter-rater reliability, the intraclass correlation coefficient (2, 1) was 0.969. The intraclass correlation coefficients (1, 2) for test-retest reliability ranged from 0.991 to 0.999. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The results indicate that ultrasound measurements of interspinous process distance are highly reliable even when measured only once by a single person. PMID:27630399

  13. Absolute and relative reliability of lumbar interspinous process ultrasound imaging measurements

    PubMed Central

    Tozawa, Ryosuke; Katoh, Munenori; Aramaki, Hidefumi; Kawasaki, Tsubasa; Nishikawa, Yuichi; Kumamoto, Tsuneo; Fujinawa, Osamu

    2016-01-01

    [Purpose] The intra- and inter-examiner reliabilities of lumbar interspinous process distances measured by ultrasound imaging were examined. [Subjects and Methods] The subjects were 10 males who had no history of orthopedic diseases or dysfunctions. Ten lumbar interspinous images from 360 images captured from 10 subjects were selected. The 10 images were measured by nine examiners. The lumbar interspinous process distance measurements were performed five times by each examiner. In addition, four of the nine examiners measured the distances again after 4 days for test-retest analysis. In statistical analysis, the intraclass correlation coefficient was used to investigate relative reliability, and Bland-Altman analysis was used to investigate absolute reliability. [Results] The intraclass correlation coefficients (1, 1) for intra-examiner reliability ranged from 0.985 to 0.998. For inter-rater reliability, the intraclass correlation coefficient (2, 1) was 0.969. The intraclass correlation coefficients (1, 2) for test-retest reliability ranged from 0.991 to 0.999. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The results indicate that ultrasound measurements of interspinous process distance are highly reliable even when measured only once by a single person. PMID:27630399

  14. Absolute and relative reliability of lumbar interspinous process ultrasound imaging measurements.

    PubMed

    Tozawa, Ryosuke; Katoh, Munenori; Aramaki, Hidefumi; Kawasaki, Tsubasa; Nishikawa, Yuichi; Kumamoto, Tsuneo; Fujinawa, Osamu

    2016-08-01

    [Purpose] The intra- and inter-examiner reliabilities of lumbar interspinous process distances measured by ultrasound imaging were examined. [Subjects and Methods] The subjects were 10 males who had no history of orthopedic diseases or dysfunctions. Ten lumbar interspinous images from 360 images captured from 10 subjects were selected. The 10 images were measured by nine examiners. The lumbar interspinous process distance measurements were performed five times by each examiner. In addition, four of the nine examiners measured the distances again after 4 days for test-retest analysis. In statistical analysis, the intraclass correlation coefficient was used to investigate relative reliability, and Bland-Altman analysis was used to investigate absolute reliability. [Results] The intraclass correlation coefficients (1, 1) for intra-examiner reliability ranged from 0.985 to 0.998. For inter-rater reliability, the intraclass correlation coefficient (2, 1) was 0.969. The intraclass correlation coefficients (1, 2) for test-retest reliability ranged from 0.991 to 0.999. The Bland-Altman analysis results indicated no systematic error. [Conclusion] The results indicate that ultrasound measurements of interspinous process distance are highly reliable even when measured only once by a single person.

  15. Mini-implants and miniplates generate sub-absolute and absolute anchorage

    PubMed Central

    Consolaro, Alberto

    2014-01-01

    The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces.Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage. PMID:25162561

  16. An All Fiber White Light Interferometric Absolute Temperature Measurement System

    PubMed Central

    Kim, Jeonggon Harrison

    2008-01-01

    Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

  17. Measurement of Disintegration Rates and Absolute {gamma}-ray Intensities

    SciTech Connect

    DeVries, Daniel J.; Griffin, Henry C.

    2006-03-13

    The majority of practical radioactive materials decay by modes that include {gamma}-ray emission. For questions of 'how much' or 'how pure', one must know the absolute intensities of the major radiations. We are using liquid scintillation counting (LSC) to measurements of disintegration rates, coupled with {gamma}-ray spectroscopy to measure absolute {gamma}-ray emission probabilities. Described is a study of the 227Th chain yielding absolute {gamma}-ray intensities with {approx}0.5% accuracy and information on LSC efficiencies.

  18. Absolute Antenna Calibration at the US National Geodetic Survey

    NASA Astrophysics Data System (ADS)

    Mader, G. L.; Bilich, A. L.

    2012-12-01

    Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna models and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these models into analysis software. Determination of antenna phase center behavior is known as "antenna calibration". Since 1994, NGS has computed relative antenna calibrations for more than 350 antennas. In recent years, the geodetic community has moved to absolute calibrations - the IGS adopted absolute antenna phase center calibrations in 2006 for use in their orbit and clock products, and NGS's CORS group began using absolute antenna calibration upon the release of the new CORS coordinates in IGS08 epoch 2005.00 and NAD 83(2011,MA11,PA11) epoch 2010.00. Although NGS relative calibrations can be and have been converted to absolute, it is considered best practice to independently measure phase center characteristics in an absolute sense. Consequently, NGS has developed and operates an absolute calibration system. These absolute antenna calibrations accommodate the demand for greater accuracy and for 2-dimensional (elevation and azimuth) parameterization. NGS will continue to provide calibration values via the NGS web site www.ngs.noaa.gov/ANTCAL, and will publish calibrations in the ANTEX format as well as the legacy ANTINFO

  19. Absolute and convective instabilities and noise-sustained structures in the Couette-Taylor system with an axial flow

    NASA Astrophysics Data System (ADS)

    Tsameret, Avraham; Steinberg, Victor

    1994-02-01

    A detailed study of the Couette-Taylor system with axial flow in the range of Reynolds number Re up to 4.5, which is characterized by the propagating Taylor-vortices (PTV's) state, is presented. Two methods to measure the convective instability line are described. Comparative studies of the PTV's in the absolutely and convectively unstable regions are given. It was found that at Re<1 the PTV's appear first at the outlet at the absolute instability transition. At Re>1 the PTV's are also sustained in the convectively unstable region, but the properties of the PTV's in the absolutely and convectively unstable regions differ distinctively. In both regions the PTV's are characterized by the existence of an interface separating the pattern state from the Couette-Poiseuille flow. The interface is stationary in the absolutely unstable region and fluctuates in the convectively unstable region. The distance from the inlet to the interface changes as both control parameters ɛ¯ and Re are varied, where ɛ¯ is the distance from the convective line. This dependence is, however, different in both regions. In the absolutely unstable region the healing length is scaled with the PTV's group velocity at all values of ɛ¯ and Re, and diverges at the absolute instability transition line. In the convectively unstable region the healing length does not obey the general scaling but is about inversely proportional to ɛ¯. The most distinctive difference in the PTV's behavior in the two regions is a different sensitivity to noise. A time-dependent spatial profile of the PTV's leads to a broadband power spectrum of the velocity in the convectively unstable region near the outlet. The PTV's velocity power spectrum in the absolutely unstable region is, on the other hand, noise-free. The different sensitivity to noise was used as an experimental criterion to locate the absolute instability line for Re>1. The wave-number selection is also found to be different in both regions. As a result

  20. Feedback in distance education.

    PubMed

    Hudspeth, D

    1988-01-01

    Some tips, strategies, and techniques are presented for incorporating learner feedback into distance education courses. The most common form of learner feedback is immediate Knowledge of Response (KR). This general term can be delineated further as either Knowledge of Correct Response (KCR) or Knowledge of Incorrect Response (KIR). KCR is most useful for learning tasks that require a high level of automatic response such as vocabulary development and naming chemical structures. It also can be used for higher levels of learning. KIR occurs when the learner makes a response and knows only whether the response was correct or incorrect. If the learner was incorrect, the correct answer is not provided. Distant learners, as well as learners in a typical classroom, benefit from positive feedback, e.g., a few words written on the side of an assignment or a short note of encouragement. Personalized feedback tells students if they are performing satisfactorily and, if provided early in a course, can help reduce student attrition. If immediate feedback after an examination cannot be provided, every effort should be made to score and return the test as soon as possible before the student is expected to begin study on subsequent lessons. If this is not possible, a test review sheet could be mailed back upon receipt of the examination. Microcomputers are devices that can provide rapid and useful feedback, yet many methods that do not rely on computers can provide feedback. These include practice tests, small group exercises, and checklist response sheets. In addition to formally providing feedback after an assignment or examination, it is possible to use the principles of feedback by embedding questions and answers in text, audio, or video materials.

  1. Using Blur to Affect Perceived Distance and Size

    PubMed Central

    HELD, ROBERT T.; COOPER, EMILY A.; O’BRIEN, JAMES F.; BANKS, MARTIN S.

    2011-01-01

    We present a probabilistic model of how viewers may use defocus blur in conjunction with other pictorial cues to estimate the absolute distances to objects in a scene. Our model explains how the pattern of blur in an image together with relative depth cues indicates the apparent scale of the image’s contents. From the model, we develop a semiautomated algorithm that applies blur to a sharply rendered image and thereby changes the apparent distance and scale of the scene’s contents. To examine the correspondence between the model/algorithm and actual viewer experience, we conducted an experiment with human viewers and compared their estimates of absolute distance to the model’s predictions. We did this for images with geometrically correct blur due to defocus and for images with commonly used approximations to the correct blur. The agreement between the experimental data and model predictions was excellent. The model predicts that some approximations should work well and that others should not. Human viewers responded to the various types of blur in much the way the model predicts. The model and algorithm allow one to manipulate blur precisely and to achieve the desired perceived scale efficiently. PMID:21552429

  2. The Relationship between Running Economy and Biomechanical Variables in Distance Runners

    ERIC Educational Resources Information Center

    Tartaruga, Marcus Peikriszwili; Brisswalter, Jeanick; Peyre-Tartaruga, Leonardo Alexandre; Avila, Aluisio Otavio Vargas; Alberton, Cristine Lima; Coertjens, Marcelo; Cadore, Eduardo Lusa; Tiggemann, Carlos Leandro; Silva, Eduardo Marczwski; Kruel, Luiz Fernando Martins

    2012-01-01

    In this study, we analyzed the relationship between running economy (RE) and biomechanical parameters in a group running at the same relative intensity and same absolute velocity. Sixteen homogeneous male long-distance runners performed a test to determine RE at 4.4 m.s[superscript -1], corresponding to 11.1% below velocity at the ventilatory…

  3. DISTANCE SCALE ZERO POINTS FROM GALACTIC RR LYRAE STAR PARALLAXES

    SciTech Connect

    Benedict, G. Fritz; McArthur, Barbara E.; Barnes, Thomas G.; Feast, Michael W.; Harrison, Thomas E.; Bean, Jacob L.; Kolenberg, Katrien; Menzies, John W.; Laney, C. D.; Chaboyer, Brian; Fossati, Luca; Nesvacil, Nicole; Smith, Horace A.; Kochukhov, Oleg; Nelan, Edmund P.; Taylor, Denise; Shulyak, D. V.; Freedman, Wendy L.

    2011-12-15

    We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars-five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids: VY Pyx and {kappa} Pav. We obtained these results with astrometric data from Fine Guidance Sensors, white-light interferometers on Hubble Space Telescope. We find absolute parallaxes in milliseconds of arc: RZ Cep, 2.12 {+-} 0.16 mas; XZ Cyg, 1.67 {+-} 0.17 mas; SU Dra, 1.42 {+-} 0.16 mas; RR Lyr, 3.77 {+-} 0.13 mas; UV Oct, 1.71 {+-} 0.10 mas; VY Pyx, 6.44 {+-} 0.23 mas; and {kappa} Pav, 5.57 {+-} 0.28 mas; an average {sigma}{sub {pi}}/{pi} = 5.4%. With these parallaxes, we compute absolute magnitudes in V and K bandpasses corrected for interstellar extinction and Lutz-Kelker-Hanson bias. Using these RR Lyrae variable star absolute magnitudes, we then derive zero points for M{sub V} -[Fe/H] and M{sub K} -[Fe/H]-log P relations. The technique of reduced parallaxes corroborates these results. We employ our new results to determine distances and ages of several Galactic globular clusters and the distance of the Large Magellanic Cloud. The latter is close to that previously derived from Classical Cepheids uncorrected for any metallicity effect, indicating that any such effect is small. We also discuss the somewhat puzzling results obtained for our two type 2 Cepheids.

  4. Absolute pitch in infant auditory learning: evidence for developmental reorganization.

    PubMed

    Saffran, J R; Griepentrog, G J

    2001-01-01

    To what extent do infants represent the absolute pitches of complex auditory stimuli? Two experiments with 8-month-old infants examined the use of absolute and relative pitch cues in a tone-sequence statistical learning task. The results suggest that, given unsegmented stimuli that do not conform to the rules of musical composition, infants are more likely to track patterns of absolute pitches than of relative pitches. A 3rd experiment tested adults with or without musical training on the same statistical learning tasks used in the infant experiments. Unlike the infants, adult listeners relied primarily on relative pitch cues. These results suggest a shift from an initial focus on absolute pitch to the eventual dominance of relative pitch, which, it is argued, is more useful for both music and speech processing.

  5. Absolute calibration of sniffer probes on Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Moseev, D.; Laqua, H. P.; Marsen, S.; Stange, T.; Braune, H.; Erckmann, V.; Gellert, F.; Oosterbeek, J. W.

    2016-08-01

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m2 per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m2 per MW injected beam power is measured.

  6. Temporal Dynamics of Microbial Rhodopsin Fluorescence Reports Absolute Membrane Voltage

    PubMed Central

    Hou, Jennifer H.; Venkatachalam, Veena; Cohen, Adam E.

    2014-01-01

    Plasma membrane voltage is a fundamentally important property of a living cell; its value is tightly coupled to membrane transport, the dynamics of transmembrane proteins, and to intercellular communication. Accurate measurement of the membrane voltage could elucidate subtle changes in cellular physiology, but existing genetically encoded fluorescent voltage reporters are better at reporting relative changes than absolute numbers. We developed an Archaerhodopsin-based fluorescent voltage sensor whose time-domain response to a stepwise change in illumination encodes the absolute membrane voltage. We validated this sensor in human embryonic kidney cells. Measurements were robust to variation in imaging parameters and in gene expression levels, and reported voltage with an absolute accuracy of 10 mV. With further improvements in membrane trafficking and signal amplitude, time-domain encoding of absolute voltage could be applied to investigate many important and previously intractable bioelectric phenomena. PMID:24507604

  7. Absolute Value Boundedness, Operator Decomposition, and Stochastic Media and Equations

    NASA Technical Reports Server (NTRS)

    Adomian, G.; Miao, C. C.

    1973-01-01

    The research accomplished during this period is reported. Published abstracts and technical reports are listed. Articles presented include: boundedness of absolute values of generalized Fourier coefficients, propagation in stochastic media, and stationary conditions for stochastic differential equations.

  8. Absolute calibration of sniffer probes on Wendelstein 7-X.

    PubMed

    Moseev, D; Laqua, H P; Marsen, S; Stange, T; Braune, H; Erckmann, V; Gellert, F; Oosterbeek, J W

    2016-08-01

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m(2) per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m(2) per MW injected beam power is measured. PMID:27587121

  9. Preparation of an oakmoss absolute with reduced allergenic potential.

    PubMed

    Ehret, C; Maupetit, P; Petrzilka, M; Klecak, G

    1992-06-01

    Synopsis Oakmoss absolute, an extract of the lichen Evernia prunastri, is known to cause allergenic skin reactions due to the presence of certain aromatic aldehydes such as atranorin, chloratranorin, ethyl hematommate and ethyl chlorohematommate. In this paper it is shown that treatment of Oakmoss absolute with amino acids such as lysine and/or leucine, lowers considerably the content of these allergenic constituents including atranol and chloratranol. The resulting Oakmoss absolute, which exhibits an excellent olfactive quality, was tested extensively in comparative studies on guinea pigs and on man. The results of the Guinea Pig Maximization Test (GPMT) and Human Repeated Insult Patch Test (HRIPT) indicate that, in comparison with the commercial test sample, the allergenicity of this new quality of Oakmoss absolute was considerably reduced, and consequently better skin tolerance of this fragrance for man was achieved. PMID:19272096

  10. Absolute Free Energies for Biomolecules in Implicit or Explicit Solvent

    NASA Astrophysics Data System (ADS)

    Berryman, Joshua T.; Schilling, Tanja

    Methods for absolute free energy calculation by alchemical transformation of a quantitative model to an analytically tractable one are discussed. These absolute free energy methods are placed in the context of other methods, and an attempt is made to describe the best practice for such calculations given the current state of the art. Calculations of the equilibria between the four free energy basins of the dialanine molecule and the two right- and left-twisted basins of DNA are discussed as examples.

  11. Heat capacity and absolute entropy of iron phosphides

    SciTech Connect

    Dobrokhotova, Z.V.; Zaitsev, A.I.; Litvina, A.D.

    1994-09-01

    There is little or no data on the thermodynamic properties of iron phosphides despite their importance for several areas of science and technology. The information available is of a qualitative character and is based on assessments of the heat capacity and absolute entropy. In the present work, we measured the heat capacity over the temperature range of 113-873 K using a differential scanning calorimeter (DSC) and calculated the absolute entropy.

  12. Distance measurement using frequency scanning interferometry with mode-hoped laser

    NASA Astrophysics Data System (ADS)

    Medhat, M.; Sobee, M.; Hussein, H. M.; Terra, O.

    2016-06-01

    In this paper, frequency scanning interferometry is implemented to measure distances up to 5 m absolutely. The setup consists of a Michelson interferometer, an external cavity tunable diode laser, and an ultra-low expansion (ULE) Fabry-Pérot (FP) cavity to measure the frequency scanning range. The distance is measured by acquiring simultaneously the interference fringes from, the Michelson and the FP interferometers, while scanning the laser frequency. An online fringe processing technique is developed to calculate the distance from the fringe ratio while removing the parts result from the laser mode-hops without significantly affecting the measurement accuracy. This fringe processing method enables accurate distance measurements up to 5 m with measurements repeatability ±3.9×10-6 L. An accurate translation stage is used to find the FP cavity free-spectral-range and therefore allow accurate measurement. Finally, the setup is applied for the short distance calibration of a laser distance meter (LDM).

  13. Global absolut gravity reference system as replacement of IGSN 71

    NASA Astrophysics Data System (ADS)

    Wilmes, Herbert; Wziontek, Hartmut; Falk, Reinhard

    2015-04-01

    The determination of precise gravity field parameters is of great importance in a period in which earth sciences are achieving the necessary accuracy to monitor and document global change processes. This is the reason why experts from geodesy and metrology joined in a successful cooperation to make absolute gravity observations traceable to SI quantities, to improve the metrological kilogram definition and to monitor mass movements and smallest height changes for geodetic and geophysical applications. The international gravity datum is still defined by the International Gravity Standardization Net adopted in 1971 (IGSN 71). The network is based upon pendulum and spring gravimeter observations taken in the 1950s and 60s supported by the early free fall absolute gravimeters. Its gravity values agreed in every case to better than 0.1 mGal. Today, more than 100 absolute gravimeters are in use worldwide. The series of repeated international comparisons confirms the traceability of absolute gravity measurements to SI quantities and confirm the degree of equivalence of the gravimeters in the order of a few µGal. For applications in geosciences where e.g. gravity changes over time need to be analyzed, the temporal stability of an absolute gravimeter is most important. Therefore, the proposition is made to replace the IGSN 71 by an up-to-date gravity reference system which is based upon repeated absolute gravimeter comparisons and a global network of well controlled gravity reference stations.

  14. Policy Deficit in Distance Education: A Transactional Distance

    ERIC Educational Resources Information Center

    Gokool-Ramdoo, Sushita

    2009-01-01

    This paper innovatively extends the application of transactional distance theory (TDT) to evidence-based policy development in Mauritius. In-depth interview data on student persistence from a range of stakeholders is used to understand the implications of distance education (DE) policy deficit. Policy deficit has surfaced as another dimension of…

  15. Transactional Distance and Autonomy in a Distance Learning Environment

    ERIC Educational Resources Information Center

    Vasiloudis, G.; Koutsouba, M.; Giossos, Y.; Mavroidis, I.

    2015-01-01

    This paper studies the transactional distance between the students and the tutor as well as the autonomy of students in a postgraduate course of the Hellenic Open University (HOU). The aim of the paper is to examine how the relation between autonomy and transactional distance evolves during an academic year and how this relation is affected by…

  16. Lifelong Learning & Distance Higher Education. Perspectives on Distance Education

    ERIC Educational Resources Information Center

    McIntosh, Christopher, Ed.

    2005-01-01

    Reflecting a common objective of ensuring quality Education for All, this book is a joint initiative of UNESCO and COL and jointly published. Lifelong Learning in Distance Higher Education brings together a diverse group of experts from many countries. The book provides a clear picture of the challenges, problems and potential of distance higher…

  17. Harmonizing the RR Lyrae and Clump Distance Scales-Stretching the Short Distance Scale to Intermediate Ranges?

    SciTech Connect

    Popowski, P.

    2000-01-31

    I explore the consequences of making the RR Lyrae and clump giant distance scales consistent in the solar neighborhood, Galactic bulge and Large Magellanic Cloud (LMC). I employ two major assumptions: (1) that the absolute magnitude -metallicity, M{sub V}(RR) - [Fe/H], relation for RR Lyrae stars is universal, and (2) that absolute I-magnitudes of clump giants, M{sub I}(RC), in Baade's Window can be inferred from the local Hipparcos calibration of clump giants' magnitudes. A comparison between the solar neighborhood and Baade's Window sets M{sub V}(RR) at [Fe/H] = -1.6 in the range (0.59 {+-} 0.05, 0.70 {+-} 0.05), somewhat brighter than the statistical parallax solution. A comparison between Baade's Window and the LMC sets the M{sub I}{sup LMC}(RC) in the range (-0.33 {+-} 0.09, -0.53 {+-} 0.09). The distance modulus to the LMC is {mu}{sup LMC} {element_of} (18.24 {+-} 0.08, 18.44 {+-} 0.07). I argue that the currently available information slightly favors the short distance scale but is insufficient to select the correct solutions with high confidence.

  18. The cosmological distance ladder: Distance and time in the universe

    NASA Astrophysics Data System (ADS)

    Rowan-Robinson, Michael

    An introduction to modern astronomy is given from the point of view of distance measurement, from the scale of the solar system up to the largest cosmological scales. A historical and philosophical background to the measurement of distance and time in the universe is given, and the measurement of distances within the Galaxy is examined. The structure and evolution of stars and galaxies are described, and both primary and secondary methods of measuring distances to external galaxies are critically reviewed. An elementary introduction to the relativistic Big Bang and other cosmological models is given, the value of the Hubble constant is reviewed, and the origins of the current controversy over the distance scale are examined. THe size and age of the universe are discussed, and the questions of whether there are characteristic length scales in the universe and whether humanity exists at a special time in the universe are considered.

  19. Method to obtain absolute impurity density profiles combining charge exchange and beam emission spectroscopy without absolute intensity calibrationa)

    NASA Astrophysics Data System (ADS)

    Kappatou, A.; Jaspers, R. J. E.; Delabie, E.; Marchuk, O.; Biel, W.; Jakobs, M. A.

    2012-10-01

    Investigation of impurity transport properties in tokamak plasmas is essential and a diagnostic that can provide information on the impurity content is required. Combining charge exchange recombination spectroscopy (CXRS) and beam emission spectroscopy (BES), absolute radial profiles of impurity densities can be obtained from the CXRS and BES intensities, electron density and CXRS and BES emission rates, without requiring any absolute calibration of the spectra. The technique is demonstrated here with absolute impurity density radial profiles obtained in TEXTOR plasmas, using a high efficiency charge exchange spectrometer with high etendue, that measures the CXRS and BES spectra along the same lines-of-sight, offering an additional advantage for the determination of absolute impurity densities.

  20. ESTIMATION OF DISTANCES TO STARS WITH STELLAR PARAMETERS FROM LAMOST

    SciTech Connect

    Carlin, Jeffrey L.; Newberg, Heidi Jo; Liu, Chao; Deng, Licai; Li, Guangwei; Luo, A-Li; Wu, Yue; Yang, Ming; Zhang, Haotong; Beers, Timothy C.; Chen, Li; Hou, Jinliang; Smith, Martin C.; Guhathakurta, Puragra; Lépine, Sébastien; Yanny, Brian; Zheng, Zheng

    2015-07-15

    We present a method to estimate distances to stars with spectroscopically derived stellar parameters. The technique is a Bayesian approach with likelihood estimated via comparison of measured parameters to a grid of stellar isochrones, and returns a posterior probability density function for each star’s absolute magnitude. This technique is tailored specifically to data from the Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) survey. Because LAMOST obtains roughly 3000 stellar spectra simultaneously within each ∼5° diameter “plate” that is observed, we can use the stellar parameters of the observed stars to account for the stellar luminosity function and target selection effects. This removes biasing assumptions about the underlying populations, both due to predictions of the luminosity function from stellar evolution modeling, and from Galactic models of stellar populations along each line of sight. Using calibration data of stars with known distances and stellar parameters, we show that our method recovers distances for most stars within ∼20%, but with some systematic overestimation of distances to halo giants. We apply our code to the LAMOST database, and show that the current precision of LAMOST stellar parameters permits measurements of distances with ∼40% error bars. This precision should improve as the LAMOST data pipelines continue to be refined.

  1. Globular cluster distances from the RR Lyrae log(period)-infrared magnitude relation

    NASA Astrophysics Data System (ADS)

    Longmore, A. J.; Dixon, R.; Skillen, I.; Jameson, R. F.; Fernley, J. A.

    1990-12-01

    The present determinations of log(period)-2.2 micron IR relationship for RR Lyr stars in eight clusters indicate no sign of scatter in the relation apart from observational error. It is suggested that very accurate relative distances, insensitive to both reddening errors and the effects of metallicity, are obtainable, although mass differences between variables in different clusters may still introduce relative distance uncertainties. A comparison of the absolute calibration of K magnitudes of two field stars obtained with an IR-flux method form of the Baade-Wesselink analysis to three other sets of distance measurements shows good agreement with those of Richer and Fahlman (1987).

  2. Distance Teaching and Learning Academy.

    ERIC Educational Resources Information Center

    Gosmire, Doreen; Vondruska, Judy

    2001-01-01

    Describes the DTL (Distance Teaching and Learning) Academy that was developed to help South Dakota's teachers use technology more effectively, including two-way videoconferencing equipment. Topics include goals; influence of the TTL (Teaching and Learning Academy); developing distance education courses; professional development opportunities for…

  3. Distance Education: Educational Trajectory Control

    ERIC Educational Resources Information Center

    Isaev, Andrey; Kravets, Alla; Isaeva, Ludmila; Fomenkov, Sergey

    2013-01-01

    Distance education has become a rather popular form of education recently. The advantages of this form are obvious and well-known. They include asynchronous learning, individualized learning trajectories and convenient case technologies. However, the distance form of education is not able to form the trainee's hands-on experience, especially…

  4. "Distance Education", 2000-2010

    ERIC Educational Resources Information Center

    Oviatt, Darin; Burdis, Jacob; West, Richard E.

    2012-01-01

    This article analyzes the articles published in the journal "Distance Education" from 2000-2010. The researchers analyzed these articles to determine the primary topics, research methods, key phrases in article titles, authorship, and most highly cited pieces. The development of new approaches to engage in distance education is a recurring theme…

  5. Distance Education in Rural Areas.

    ERIC Educational Resources Information Center

    Zucker, Henry

    This discussion of social and political aspects, advantages and disadvantages of distance education programs includes descriptions and examples of delivery technologies and programs in developing and developed countries. Among the social aspects considered are distance education's potential to provide a second chance to people who are trapped by…

  6. Directory of Distance Education Professionals.

    ERIC Educational Resources Information Center

    Bhushan, Bharat, Ed.; Rausaria, R. R., Ed.

    This directory of distance education professionals in India covers personnel working in open universities, correspondence course institutes, and directorates of distance education of conventional universities and other national level research institutes. The information was derived from a set of structured questionnaires sent to all involved…

  7. USAF Initiatives in Distance Learning.

    ERIC Educational Resources Information Center

    Wolfe, Thomas E.

    1996-01-01

    Examines the expansive growth of distance learning in the United States Air Force (USAF). Highlights include interactive television and the Air Technology Network that uses satellites; computer-based instruction; online electronic campus; multimedia interactive courseware; CD-ROM; distance learning benefits; data collection; administration; and…

  8. Virtual Bioinformatics Distance Learning Suite

    ERIC Educational Resources Information Center

    Tolvanen, Martti; Vihinen, Mauno

    2004-01-01

    Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material…

  9. Multimedia Equipment for Distance Education.

    ERIC Educational Resources Information Center

    Schiller, Scott S.

    1993-01-01

    Discusses the use of multimedia equipment for distance education. Topics addressed include use of the Internet; distance learning for educators; and cable television and/or fiber optics, including interactive television and satellite technology. A sidebar lists online and telecommunications providers. (LRW)

  10. Distance Education. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Fuller, Frank, Ed.; McBride, Ron, Ed.

    This document contains the papers on distance education from the SITE (Society for Information Technology & Teacher Education) 2001 conference. Topics covered include: the distance education degree program for the Master of Mathematics with a teaching option at Texas A&M University; the evolution of online learning; Internet-based distance…

  11. Distance Learning: Practice and Dilemmas

    ERIC Educational Resources Information Center

    Tatkovic, Nevenka; Sehanovic, Jusuf; Ruzic, Maja

    2006-01-01

    In accordance with the European processes of integrated and homogeneous education, the paper presents the essential viewpoints and questions covering the establishment and development of "distance learning" (DL) in Republic of Croatia. It starts from the advantages of distance learning versus traditional education taking into account some…

  12. Distance Learning and the Curriculum.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Distance education has numerous inherent philosophies to utilize in teaching-learning situation. The problem solving aspect of distance learning encourages active involvement by students in teaching-learning situations; student selection of content; teachers as guides and motivators of student learning; ordering of learning experiences in terms of…

  13. Distance Educator: A Multiskill Personality

    ERIC Educational Resources Information Center

    Malik, Sangeeta

    2013-01-01

    When we talk about a distance educator and a conventional educator the difference we found about both of them is that a distance educator needs to play multiple roles as compared to a conventional educator. They require more skills and knowledge to cater to the needs of the learner. In this article we will cover all the responsible areas of a…

  14. The Distance to M51

    NASA Astrophysics Data System (ADS)

    McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

    2016-07-01

    Great investments of observing time have been dedicated to the study of nearby spiral galaxies with diverse goals ranging from understanding the star formation process to characterizing their dark matter distributions. Accurate distances are fundamental to interpreting observations of these galaxies, yet many of the best studied nearby galaxies have distances based on methods with relatively large uncertainties. We have started a program to derive accurate distances to these galaxies. Here we measure the distance to M51—the Whirlpool galaxy—from newly obtained Hubble Space Telescope optical imaging using the tip of the red giant branch method. We measure the distance modulus to be 8.58 ± 0.10 Mpc (statistical), corresponding to a distance modulus of 29.67 ± 0.02 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian Maximum Likelihood technique that reduces measurement uncertainties. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  15. The Distance to M104

    NASA Astrophysics Data System (ADS)

    McQuinn, Kristen. B. W.; Skillman, Evan D.; Dolphin, Andrew E.; Berg, Danielle; Kennicutt, Robert

    2016-11-01

    M104 (NGC 4594; the Sombrero galaxy) is a nearby, well-studied elliptical galaxy included in scores of surveys focused on understanding the details of galaxy evolution. Despite the importance of observations of M104, a consensus distance has not yet been established. Here, we use newly obtained Hubble Space Telescope optical imaging to measure the distance to M104 based on the tip of the red giant branch (TRGB) method. Our measurement yields the distance to M104 to be 9.55 ± 0.13 ± 0.31 Mpc equivalent to a distance modulus of 29.90 ± 0.03 ± 0.07 mag. Our distance is an improvement over previous results as we use a well-calibrated, stable distance indicator, precision photometry in a optimally selected field of view, and a Bayesian maximum likelihood technique that reduces measurement uncertainties. The most discrepant previous results are due to Tully–Fisher method distances, which are likely inappropriate for M104 given its peculiar morphology and structure. Our results are part of a larger program to measure accurate distances to a sample of well-known spiral galaxies (including M51, M74, and M63) using the TRGB method. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  16. Academic Advisement for Distance Learners.

    ERIC Educational Resources Information Center

    Fornshell, George K.

    1993-01-01

    Describes the use of the Electronic ClassRoom, a teleconferencing tool, for the academic advisement of graduate distance education students at Nova University (Florida). Topics addressed include distance learning students' problems and the need for advisement; scheduling; the use of Tymnet; academic advisement delivery models; and future research…

  17. Faculty Attitudes about Distance Education

    ERIC Educational Resources Information Center

    Smidt, Esther; McDyre, Brian; Bunk, Jennifer; Li, Rui; Gatenby, Tanya

    2014-01-01

    In recent years, there has been a dramatic increase in distance learning in higher education. Given this, it is extremely important to understand faculty attitudes about distance education, not only because they can vary widely, but also because it is the faculty, through their design and implementation of online courses, that will shape the…

  18. Adult Education at a Distance.

    ERIC Educational Resources Information Center

    Gaudet, Alphonse

    This document, which examines the use of educational technologies for distance education for adults in Canada, consists of five narrative sections and a bibliography. The first section introduces the topic and the document's objectives (to describe those technologies used in Canadian adult distance education, paying particular attention to those…

  19. The sesquiterpenoid nootkatone and the absolute configuration of a dibromo derivative.

    PubMed

    Sauer, Anne M; Fronczek, Frank R; Zhu, Betty C R; Crowe, William E; Henderson, Gregg; Laine, Roger A

    2003-05-01

    Nootkatone, or (4R,4aS,6R)-4,4a,5,6,7,8-hexahydro-4,4a-dimethyl-6-(1-methylethenyl)naphthalen-2(3H)-one, C(15)H(22)O, a sesquiterpene with strong repellent properties against Formosan subterranean termites and other insects, has the valencene skeleton. The dibromo derivative (1S,3R,4S,4aS,6R,8aR)-1,3-dibromo-6-isopropyl-4,4a-dimethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-2-one, C(15)H(24)Br(2)O, has two independent molecules in the asymmetric unit, which differ in the rotation of the isopropyl group with respect to the main skeleton. The C-Br distances are in the range 1.950 (4)-1.960 (4) A. Both independent molecules form zigzag chains, with very short intermolecular carbonyl-carbonyl interactions, having the perpendicular motif and O...C distances of 2.886 (6) and 2.898 (6) A. These chains are flanked by intermolecular Br...Br interactions of distances in the range 4.067 (1)-4.218 (1) A. The absolute configuration of the dibromo derivative was determined, from which that of nootkatone was inferred. PMID:12743407

  20. Absolute irradiance of the Moon for on-orbit calibration

    USGS Publications Warehouse

    Stone, T.C.; Kieffer, H.H.; ,

    2002-01-01

    The recognized need for on-orbit calibration of remote sensing imaging instruments drives the ROLO project effort to characterize the Moon for use as an absolute radiance source. For over 5 years the ground-based ROLO telescopes have acquired spatially-resolved lunar images in 23 VNIR (Moon diameter ???500 pixels) and 9 SWIR (???250 pixels) passbands at phase angles within ??90 degrees. A numerical model for lunar irradiance has been developed which fits hundreds of ROLO images in each band, corrected for atmospheric extinction and calibrated to absolute radiance, then integrated to irradiance. The band-coupled extinction algorithm uses absorption spectra of several gases and aerosols derived from MODTRAN to fit time-dependent component abundances to nightly observations of standard stars. The absolute radiance scale is based upon independent telescopic measurements of the star Vega. The fitting process yields uncertainties in lunar relative irradiance over small ranges of phase angle and the full range of lunar libration well under 0.5%. A larger source of uncertainty enters in the absolute solar spectral irradiance, especially in the SWIR, where solar models disagree by up to 6%. Results of ROLO model direct comparisons to spacecraft observations demonstrate the ability of the technique to track sensor responsivity drifts to sub-percent precision. Intercomparisons among instruments provide key insights into both calibration issues and the absolute scale for lunar irradiance.

  1. Absolute neutrophil values in malignant patients on cytotoxic chemotherapy.

    PubMed

    Madu, A J; Ibegbulam, O G; Ocheni, S; Madu, K A; Aguwa, E N

    2011-01-01

    A total of eighty patients with various malignancies seen between September 2008 and April 2009 at the University of Nigeria Teaching Hospital (UNTH) Ituku Ozalla, Enugu, Nigeria, had their absolute neutrophil counts, done at Days 0 and 12 of the first cycle of their various chemotherapeutic regimens. They were adult patients who had been diagnosed of various malignancies, consisting of Breast cancer 36 (45%), Non-Hodgkin's lymphoma 8 (10%), Hodgkin's lymphoma 13 (16.25%), Colorectal carcinoma 6 (7.5%), Multiple myeloma 7 (8.75%), Cervical carcinoma 1 (1.25%) and other malignancies 9 (11.25%), Manual counting of absolute neutrophil count was done using Turks solution and improved Neubauer counting chamber and Galen 2000 Olympus microscope. The socio demographic data of the patients were assessed from a questionnaire. There were 27 males (33.75%) and 53 females (66.25%). Their ages ranged from 18 - 80 years with a median of 45 years. The mean absolute neutrophil count of the respondents pre-and post chemotherapy was 3.7 +/- 2.1 x 10(9)/L and 2.5 +/- 1.6 x 10(9)/L respectively. There were significant differences in both the absolute neutrophil count (p=0.00) compared to the pre-chemotherapy values. Chemotherapeutic combinations containing cyclophosphamide and Adriamycin were observed to cause significant reduction in absolute neutrophil.

  2. The Application of Optimisation Methods to Constrain Absolute Plate Motions

    NASA Astrophysics Data System (ADS)

    Tetley, M. G.; Williams, S.; Hardy, S.; Müller, D.

    2015-12-01

    Plate tectonic reconstructions are an excellent tool for understanding the configuration and behaviour of continents through time on both global and regional scales, and are relatively well understood back to ~200 Ma. However, many of these models represent only relative motions between continents, providing little information of absolute tectonic motions and their relationship with the deep Earth. Significant issues exist in solving this problem, including how to combine constraints from multiple, diverse data into a unified model of absolute plate motions; and how to address uncertainties both in the available data, and in the assumptions involved in this process (e.g. hotspot motion, true polar wander). In deep time (pre-Pangea breakup), plate reconstructions rely more heavily on paleomagnetism, but these data often imply plate velocities much larger than those observed since the breakup of the supercontinent Pangea where plate velocities are constrained by the seafloor spreading record. Here we present two complementary techniques to address these issues, applying parallelized numerical methods to quantitatively investigate absolute plate motions through time. Firstly, we develop a data-fit optimized global absolute reference frame constrained by kinematic reconstruction data, hotspot-trail observations, and trench migration statistics. Secondly we calculate optimized paleomagnetic data-derived apparent polar wander paths (APWPs) for both the Phanerozoic and Precambrian. Paths are generated from raw pole data with optimal spatial and temporal pole configurations calculated using all known uncertainties and quality criteria to produce velocity-optimized absolute motion paths through deep time.

  3. CHARACTERIZING THE CONTAMINATING DISTANCE DISTRIBUTION FOR BAYESIAN SUPERNOVA COSMOLOGY

    SciTech Connect

    Falck, Bridget L.; Riess, Adam G.; Hlozek, Renee

    2010-11-01

    Measurements of the equation of state of dark energy from surveys of thousands of Type Ia Supernovae will be limited by spectroscopic follow-up and must therefore rely on photometric identification, increasing the chance that the sample is contaminated by core collapse supernovae (CC SNe). Bayesian methods for SN cosmology can remove contamination bias while maintaining high statistical precision but are sensitive to the choice of parameterization of the contaminating distance distribution. We use simulations to investigate the form of the contaminating distribution and its dependence on the absolute magnitudes, light curve shapes, colors, extinction, and redshifts of CC SNe. We find that the CC luminosity function (LF) dominates the distance distribution function, but its shape is increasingly distorted as the redshift increases and more CC SNe fall below the survey magnitude limit. The shapes and colors of the CC light curves generally shift the distance distribution, and their effect on the CC distances is correlated. We compare the simulated distances to the first year results of the SDSS-II SN survey and find that the SDSS distance distributions can be reproduced with simulated CC SNe that are {approx}1 mag fainter than the standard Richardson et al. LFs, which do not produce a good fit. To exploit the full power of the Bayesian parameter estimation method, parameterization of the contaminating distribution should be guided by the current knowledge of the CC LFs, coupled with the effects of the survey selection and magnitude limit, and allow for systematic shifts caused by the parameters of the distance fit.

  4. Distances, luminosities, and temperatures of the coldest known substellar objects.

    PubMed

    Dupuy, Trent J; Kraus, Adam L

    2013-09-27

    The coolest known brown dwarfs are our best analogs to extrasolar gas-giant planets. The prolific detections of such cold substellar objects in the past 2 years have spurred intensive follow-up, but the lack of accurate distances is a key gap in our understanding. We present a large sample of precise distances based on homogeneous mid-infrared astrometry that robustly establishes absolute fluxes, luminosities, and temperatures. The coolest brown dwarfs have temperatures of 400 to 450 kelvin and masses almost equal to 5 to 20 times that of Jupiter, showing they bridge the gap between hotter brown dwarfs and gas-giant planets. At these extremes, spectral energy distributions no longer follow a simple correspondence with temperature, suggesting an increasing role of other physical parameters, such as surface gravity, vertical mixing, clouds, and metallicity.

  5. Distances, luminosities, and temperatures of the coldest known substellar objects.

    PubMed

    Dupuy, Trent J; Kraus, Adam L

    2013-09-27

    The coolest known brown dwarfs are our best analogs to extrasolar gas-giant planets. The prolific detections of such cold substellar objects in the past 2 years have spurred intensive follow-up, but the lack of accurate distances is a key gap in our understanding. We present a large sample of precise distances based on homogeneous mid-infrared astrometry that robustly establishes absolute fluxes, luminosities, and temperatures. The coolest brown dwarfs have temperatures of 400 to 450 kelvin and masses almost equal to 5 to 20 times that of Jupiter, showing they bridge the gap between hotter brown dwarfs and gas-giant planets. At these extremes, spectral energy distributions no longer follow a simple correspondence with temperature, suggesting an increasing role of other physical parameters, such as surface gravity, vertical mixing, clouds, and metallicity. PMID:24009359

  6. Language distance and tree reconstruction

    NASA Astrophysics Data System (ADS)

    Petroni, Filippo; Serva, Maurizio

    2008-08-01

    Languages evolve over time according to a process in which reproduction, mutation and extinction are all possible. This is very similar to haploid evolution for asexual organisms and for the mitochondrial DNA of complex ones. Exploiting this similarity, it is possible, in principle, to verify hypotheses concerning the relationship among languages and to reconstruct their family tree. The key point is the definition of the distances among pairs of languages in analogy with the genetic distances among pairs of organisms. Distances can be evaluated by comparing grammar and/or vocabulary, but while it is difficult, if not impossible, to quantify grammar distance, it is possible to measure a distance from vocabulary differences. The method used by glottochronology computes distances from the percentage of shared 'cognates', which are words with a common historical origin. The weak point of this method is that subjective judgment plays a significant role. Here we define the distance of two languages by considering a renormalized edit distance among words with the same meaning and averaging over the two hundred words contained in a Swadesh list. In our approach the vocabulary of a language is the analogue of DNA for organisms. The advantage is that we avoid subjectivity and, furthermore, reproducibility of results is guaranteed. We apply our method to the Indo-European and the Austronesian groups, considering, in both cases, fifty different languages. The two trees obtained are, in many respects, similar to those found by glottochronologists, with some important differences as regards the positions of a few languages. In order to support these different results we separately analyze the structure of the distances of these languages with respect to all the others.

  7. Method for estimating absolute lung volumes at constant inflation pressure.

    PubMed

    Hills, B A; Barrow, R E

    1979-10-01

    A method has been devised for measuring functional residual capacity in the intact killed animal or absolute lung volumes in any excised lung preparation without changing the inflation pressure. This is achieved by titrating the absolute pressure of a chamber in which the preparation is compressed until a known volume of air has entered the lungs. This technique was used to estimate the volumes of five intact rabbit lungs and five rigid containers of known dimensions by means of Boyle's law. Results were found to agree to within +/- 1% with values determined by alternative methods. In the discussion the advantage of determining absolute lung volumes at almost any stage in a study of lung mechanics without the determination itself changing inflation pressure and, hence, lung volume is emphasized. PMID:511699

  8. System and method for calibrating a rotary absolute position sensor

    NASA Technical Reports Server (NTRS)

    Davis, Donald R. (Inventor); Permenter, Frank Noble (Inventor); Radford, Nicolaus A (Inventor)

    2012-01-01

    A system includes a rotary device, a rotary absolute position (RAP) sensor generating encoded pairs of voltage signals describing positional data of the rotary device, a host machine, and an algorithm. The algorithm calculates calibration parameters usable to determine an absolute position of the rotary device using the encoded pairs, and is adapted for linearly-mapping an ellipse defined by the encoded pairs to thereby calculate the calibration parameters. A method of calibrating the RAP sensor includes measuring the rotary position as encoded pairs of voltage signals, linearly-mapping an ellipse defined by the encoded pairs to thereby calculate the calibration parameters, and calculating an absolute position of the rotary device using the calibration parameters. The calibration parameters include a positive definite matrix (A) and a center point (q) of the ellipse. The voltage signals may include an encoded sine and cosine of a rotary angle of the rotary device.

  9. Method and apparatus for two-dimensional absolute optical encoding

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B. (Inventor)

    2004-01-01

    This invention presents a two-dimensional absolute optical encoder and a method for determining position of an object in accordance with information from the encoder. The encoder of the present invention comprises a scale having a pattern being predetermined to indicate an absolute location on the scale, means for illuminating the scale, means for forming an image of the pattern; and detector means for outputting signals derived from the portion of the image of the pattern which lies within a field of view of the detector means, the field of view defining an image reference coordinate system, and analyzing means, receiving the signals from the detector means, for determining the absolute location of the object. There are two types of scale patterns presented in this invention: grid type and starfield type.

  10. Absolute Retinal Blood Flow Measurement With a Dual-Beam Doppler Optical Coherence Tomography

    PubMed Central

    Dai, Cuixia; Liu, Xiaojing; Zhang, Hao F.; Puliafito, Carmen A.; Jiao, Shuliang

    2013-01-01

    Purpose. To test the capability of a novel dual-beam Doppler optical coherence tomography (OCT) technique for simultaneous in vivo measurement of the Doppler angle and, thus, the absolute retinal blood velocity and the retinal flow rate, without the influence of motion artifacts. Methods. A novel dual-beam Doppler spectral domain OCT (SD-OCT) was developed. The two probing beams are separated with a controllable distance along an arbitrary direction, both of which are controlled by two independent 2D optical scanners. Two sets of optical Doppler tomography (ODT) images are acquired simultaneously. The Doppler angle of each blood vessel segment is calculated from the relative coordinates of the centers of the blood vessel in the two corresponding ODT images. The absolute blood flow velocity and the volumetric blood flow rate can then be calculated. To measure the total retinal blood flow, we used a circular scan pattern centered at the optic disc to obtain two sets of concentric OCT/ODT images simultaneously. Results. We imaged two normal human subjects at ages of 48 and 34 years. The total retinal blood flow rates of the two human subjects were calculated to be 47.01 μL/min (older subject) and 51.37 μL/min (younger subject), respectively. Results showed that the performance of this imaging system is immune to eye movement, since the two sets of ODT images were acquired simultaneously. Conclusions. The dual-beam OCT/ODT system is successful in measuring the absolute retinal blood velocity and the volumetric flow rate. The advantage of the technique is that the two sets of ODT images used for the calculation are acquired simultaneously, which eliminates the influence of eye motion and ensures the accuracy of the calculated hemodynamic parameters. PMID:24222303

  11. GeMS MCAO observations of the Galactic globular cluster NGC 2808: the absolute age

    NASA Astrophysics Data System (ADS)

    Massari, D.; Fiorentino, G.; McConnachie, A.; Bono, G.; Dall'Ora, M.; Ferraro, I.; Iannicola, G.; Stetson, P. B.; Turri, P.; Tolstoy, E.

    2016-02-01

    Context. Globular clusters are the oldest stellar systems in the Milky Way, and they probe the early epoch of the Galaxy formation. However, the uncertainties on their absolute age are still too large to soundly constrain how the Galactic structures have assembled. Aims: The aim of this work is to obtain an accurate estimate of the absolute age of the globular cluster NGC 2808 using deep IR data obtained with the multi-conjugate adaptive optics system operating at the Gemini South telescope (GeMS). Methods: This exquisite photometry, combined with that obtained in V and I-bands with HST, allowed us to detect the faint Main Sequence Knee feature in NGC 2808 colour magnitude diagram. The difference between this point and the main sequence turn-off is a good age estimator that provides ages with unprecedented accuracy. Results: We find that NGC 2808 has an age of t = 10.9 ± 0.7 (intrinsic) ±0.45 (metallicity term) Gyr. A possible contamination by He-enhanced population could make the cluster up to 0.25 Gyr older. Although this age estimate agrees with the age coming from the classical turn-off method (t = 11.0 Gyr), its uncertainty is a factor ~3 better, since it avoids systematics in reddening, distance assumptions, and photometric zero point determination. The final absolute age indicates that NGC 2808 is slightly younger than other Galactic globular clusters with similar metallicity. Tables of the photometry are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A51

  12. Neural Sensitivity to Absolute and Relative Anticipated Reward in Adolescents

    PubMed Central

    Vaidya, Jatin G.; Knutson, Brian; O'Leary, Daniel S.; Block, Robert I.; Magnotta, Vincent

    2013-01-01

    Adolescence is associated with a dramatic increase in risky and impulsive behaviors that have been attributed to developmental differences in neural processing of rewards. In the present study, we sought to identify age differences in anticipation of absolute and relative rewards. To do so, we modified a commonly used monetary incentive delay (MID) task in order to examine brain activity to relative anticipated reward value (neural sensitivity to the value of a reward as a function of other available rewards). This design also made it possible to examine developmental differences in brain activation to absolute anticipated reward magnitude (the degree to which neural activity increases with increasing reward magnitude). While undergoing fMRI, 18 adolescents and 18 adult participants were presented with cues associated with different reward magnitudes. After the cue, participants responded to a target to win money on that trial. Presentation of cues was blocked such that two reward cues associated with $.20, $1.00, or $5.00 were in play on a given block. Thus, the relative value of the $1.00 reward varied depending on whether it was paired with a smaller or larger reward. Reflecting age differences in neural responses to relative anticipated reward (i.e., reference dependent processing), adults, but not adolescents, demonstrated greater activity to a $1 reward when it was the larger of the two available rewards. Adults also demonstrated a more linear increase in ventral striatal activity as a function of increasing absolute reward magnitude compared to adolescents. Additionally, reduced ventral striatal sensitivity to absolute anticipated reward (i.e., the difference in activity to medium versus small rewards) correlated with higher levels of trait Impulsivity. Thus, ventral striatal activity in anticipation of absolute and relative rewards develops with age. Absolute reward processing is also linked to individual differences in Impulsivity. PMID:23544046

  13. Neural sensitivity to absolute and relative anticipated reward in adolescents.

    PubMed

    Vaidya, Jatin G; Knutson, Brian; O'Leary, Daniel S; Block, Robert I; Magnotta, Vincent

    2013-01-01

    Adolescence is associated with a dramatic increase in risky and impulsive behaviors that have been attributed to developmental differences in neural processing of rewards. In the present study, we sought to identify age differences in anticipation of absolute and relative rewards. To do so, we modified a commonly used monetary incentive delay (MID) task in order to examine brain activity to relative anticipated reward value (neural sensitivity to the value of a reward as a function of other available rewards). This design also made it possible to examine developmental differences in brain activation to absolute anticipated reward magnitude (the degree to which neural activity increases with increasing reward magnitude). While undergoing fMRI, 18 adolescents and 18 adult participants were presented with cues associated with different reward magnitudes. After the cue, participants responded to a target to win money on that trial. Presentation of cues was blocked such that two reward cues associated with $.20, $1.00, or $5.00 were in play on a given block. Thus, the relative value of the $1.00 reward varied depending on whether it was paired with a smaller or larger reward. Reflecting age differences in neural responses to relative anticipated reward (i.e., reference dependent processing), adults, but not adolescents, demonstrated greater activity to a $1 reward when it was the larger of the two available rewards. Adults also demonstrated a more linear increase in ventral striatal activity as a function of increasing absolute reward magnitude compared to adolescents. Additionally, reduced ventral striatal sensitivity to absolute anticipated reward (i.e., the difference in activity to medium versus small rewards) correlated with higher levels of trait Impulsivity. Thus, ventral striatal activity in anticipation of absolute and relative rewards develops with age. Absolute reward processing is also linked to individual differences in Impulsivity. PMID:23544046

  14. Assessment of absolute added correlative coding in optical intensity modulation and direct detection channels

    NASA Astrophysics Data System (ADS)

    Dong-Nhat, Nguyen; Elsherif, Mohamed A.; Malekmohammadi, Amin

    2016-06-01

    The performance of absolute added correlative coding (AACC) modulation format with direct detection has been numerically and analytically reported, targeting metro data center interconnects. Hereby, the focus lies on the performance of the bit error rate, noise contributions, spectral efficiency, and chromatic dispersion tolerance. The signal space model of AACC, where the average electrical and optical power expressions are derived for the first time, is also delineated. The proposed modulation format was also compared to other well-known signaling, such as on-off-keying (OOK) and four-level pulse-amplitude modulation, at the same bit rate in a directly modulated vertical-cavity surface-emitting laser-based transmission system. The comparison results show a clear advantage of AACC in achieving longer fiber delivery distance due to the higher dispersion tolerance.

  15. Uvby-beta photometry of visual double stars - Absolute magnitudes of intrinsically bright stars

    NASA Astrophysics Data System (ADS)

    Olsen, E. H.

    1982-05-01

    Individual absolute visual magnitudes M(v) are derived for intrinsically bright stars and evolved stars. The results are collected for 106 objects believed to be members of binary systems. uvby-beta photometry was empirically calibrated in terms of M(v) for main sequence stars and photoelectrically determined apparent magnitudes. The derived M(v) values are not significantly different from those stated in the Wilson catalogue (1976). Binary systems with main sequence primaries and secondary components off the main sequence were also investigated. Several systems in which at least one component may be in the pre-main sequence contraction stage are pointed out. A wide variety of comments and derived data are given individually for 136 double stars, including metallicities, distance moduli, and masses.

  16. Non-Invasive Method of Determining Absolute Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

    2004-01-01

    A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

  17. Absolutely maximally entangled states, combinatorial designs, and multiunitary matrices

    NASA Astrophysics Data System (ADS)

    Goyeneche, Dardo; Alsina, Daniel; Latorre, José I.; Riera, Arnau; Życzkowski, Karol

    2015-09-01

    Absolutely maximally entangled (AME) states are those multipartite quantum states that carry absolute maximum entanglement in all possible bipartitions. AME states are known to play a relevant role in multipartite teleportation, in quantum secret sharing, and they provide the basis novel tensor networks related to holography. We present alternative constructions of AME states and show their link with combinatorial designs. We also analyze a key property of AME states, namely, their relation to tensors, which can be understood as unitary transformations in all of their bipartitions. We call this property multiunitarity.

  18. Absolute photon-flux measurements in the vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Haddad, G. N.

    1974-01-01

    Absolute photon-flux measurements in the vacuum ultraviolet have extended to short wavelengths by use of rare-gas ionization chambers. The technique involves the measurement of the ion current as a function of the gas pressure in the ion chamber. The true value of the ion current, and hence the absolute photon flux, is obtained by extrapolating the ion current to zero gas pressure. Examples are given at 162 and 266 A. The short-wavelength limit is determined only by the sensitivity of the current-measuring apparatus and by present knowledge of the photoionization processes that occur in the rate gases.

  19. Measurements of the reactor neutron power in absolute units

    SciTech Connect

    Lebedev, G. V.

    2015-12-15

    The neutron power of the reactor of the Yenisei space nuclear power plant is measured in absolute units using the modernized method of correlation analysis during the ground-based tests of the Yenisei prototypes. Results of the experiments are given. The desired result is obtained in a series of experiments carried out at the stage of the plant preparation for tests. The acceptability of experimental data is confirmed by the results of measuring the reactor neutron power in absolute units at the nominal level by the thermal balance during the life cycle tests of the ground prototypes.

  20. Absolute Stability Analysis of a Phase Plane Controlled Spacecraft

    NASA Technical Reports Server (NTRS)

    Jang, Jiann-Woei; Plummer, Michael; Bedrossian, Nazareth; Hall, Charles; Jackson, Mark; Spanos, Pol

    2010-01-01

    Many aerospace attitude control systems utilize phase plane control schemes that include nonlinear elements such as dead zone and ideal relay. To evaluate phase plane control robustness, stability margin prediction methods must be developed. Absolute stability is extended to predict stability margins and to define an abort condition. A constrained optimization approach is also used to design flex filters for roll control. The design goal is to optimize vehicle tracking performance while maintaining adequate stability margins. Absolute stability is shown to provide satisfactory stability constraints for the optimization.

  1. From Hubble's Next Generation Spectral Library (NGSL) to Absolute Fluxes

    NASA Astrophysics Data System (ADS)

    Heap, S. R.; Lindler, D.

    2016-05-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R˜1000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.03 μ. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsl/. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We have therefore developed an observing procedure, data-reduction procedure, and correction algorithms that should yield fluxes with uncertainties less than 1%.

  2. A general relativistic model for free-fall absolute gravimeters

    NASA Astrophysics Data System (ADS)

    Tan, Yu-Jie; Shao, Cheng-Gang; Li, Jia; Hu, Zhong-Kun

    2016-04-01

    Although the relativistic manifestations of gravitational fields in gravimetry were first studied 40 years ago, the relativistic effects combined with free-fall absolute gravimeters have rarely been considered. In light of this, we present a general relativistic model for free-fall absolute gravimeters in a local-Fermi coordinates system, where we focus on effects related to the measuring devices: relativistic transverse Doppler effects, gravitational redshift effects and Earth’s rotation effects. Based on this model, a general relativistic expression of the measured gravity acceleration is obtained.

  3. STS-9 Shuttle grow - Ram angle effect and absolute intensities

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.; Mende, S. B.; Clifton, K. S.

    1986-01-01

    Visible imagery from Space Shuttle mission STS-9 (Spacelab 1) has been analyzed for the ram angle effect and the absolute intensity of glow. The data are compared with earlier measurements and the anomalous high intensities at large ram angles are confirmed. Absolute intensities of the ram glow on the shuttle tile, at 6563 A, are observed to be about 20 times more intense than those measured on the AE-E spacecraft. Implications of these observations for an existing theory of glow involving NO2 are presented.

  4. Absolute range calibration for JASON-1 and ENVISAT using a dedicated transponder

    NASA Astrophysics Data System (ADS)

    Cristea, E.; Pesec, P.

    2003-04-01

    Altimeter waveforms are used to study absolute range calibration for the altimeters on board of JASON-1 and ENVISAT. As a uniquely defined terrestrial reflection surface, a transponder is deployed within the footprint of the altimeter. The waveforms corresponding to the transponder distinguish themselves from the other waveforms resulting from natural targets in power and shape. When a satellite-borne altimeter passes over a ground-based active transponder, it makes within 3 to 4 seconds, 3000 - 4000 measurements of the satellite to transponder separation. That distance (range) varies in a parabolic fashion so that, when a parabolic curve is fitted to the measurements, the range at the point of the closest approach, that is the vertex of this parabola, can be determined with a resolution < 1mm. The accuracy of a single measurement of this sort is limited to about 2 - 3 cm by the ability to model the propagation delay in the atmosphere. The technique of using a dedicated transponder eliminates error sources such as tides and sea state bias and resolves the unknown altimeter calibration constant. Best results are obtained when the range window of the radar altimeter is preset to a fixed value during the transponder overpass, and this has been successfully used on RA-2 on board of ENVISAT. The poster presents the concept of absolute range calibration using a transponder and will show numerical results if relevant data are available.

  5. Implications of an absolute simultaneity theory for cosmology and universe acceleration.

    PubMed

    Kipreos, Edward T

    2014-01-01

    An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT), has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift-distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe. PMID:25536116

  6. Camera-based speckle noise reduction for 3-D absolute shape measurements.

    PubMed

    Zhang, Hao; Kuschmierz, Robert; Czarske, Jürgen; Fischer, Andreas

    2016-05-30

    Simultaneous position and velocity measurements enable absolute 3-D shape measurements of fast rotating objects for instance for monitoring the cutting process in a lathe. Laser Doppler distance sensors enable simultaneous position and velocity measurements with a single sensor head by evaluating the scattered light signals. The superposition of several speckles with equal Doppler frequency but random phase on the photo detector results in an increased velocity and shape uncertainty, however. In this paper, we present a novel image evaluation method that overcomes the uncertainty limitations due to the speckle effect. For this purpose, the scattered light is detected with a camera instead of single photo detectors. Thus, the Doppler frequency from each speckle can be evaluated separately and the velocity uncertainty decreases with the square root of the number of camera lines. A reduction of the velocity uncertainty by the order of one magnitude is verified by the numerical simulations and experimental results, respectively. As a result, the measurement uncertainty of the absolute shape is not limited by the speckle effect anymore. PMID:27410133

  7. Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO

    SciTech Connect

    Lu, Jia-Shu; Cao, Jun; Li, Yu-Feng; Zhou, Shun

    2015-05-26

    A high-statistics measurement of the neutrinos from a galactic core-collapse supernova is extremely important for understanding the explosion mechanism, and studying the intrinsic properties of neutrinos themselves. In this paper, we explore the possibility to constrain the absolute scale of neutrino masses m{sub ν} via the detection of galactic supernova neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO) with a 20 kiloton liquid-scintillator detector. In assumption of a nearly-degenerate neutrino mass spectrum and a normal mass ordering, the upper bound on the absolute neutrino mass is found to be m{sub ν}<(0.83±0.24) eV at the 95% confidence level for a typical galactic supernova at a distance of 10 kpc, where the mean value and standard deviation are shown to account for statistical fluctuations. For comparison, we find that the bound in the Super-Kamiokande experiment is m{sub ν}<(0.94±0.28) eV at the same confidence level. However, the upper bound will be relaxed when the model parameters characterizing the time structure of supernova neutrino fluxes are not exactly known, and when the neutrino mass ordering is inverted.

  8. Implications of an Absolute Simultaneity Theory for Cosmology and Universe Acceleration

    PubMed Central

    Kipreos, Edward T.

    2014-01-01

    An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT), has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift–distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe. PMID:25536116

  9. Constraining absolute neutrino masses via detection of galactic supernova neutrinos at JUNO

    SciTech Connect

    Lu, Jia-Shu; Cao, Jun; Li, Yu-Feng; Zhou, Shun E-mail: caoj@ihep.ac.cn E-mail: zhoush@ihep.ac.cn

    2015-05-01

    A high-statistics measurement of the neutrinos from a galactic core-collapse supernova is extremely important for understanding the explosion mechanism, and studying the intrinsic properties of neutrinos themselves. In this paper, we explore the possibility to constrain the absolute scale of neutrino masses m{sub ν} via the detection of galactic supernova neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO) with a 20 kiloton liquid-scintillator detector. In assumption of a nearly-degenerate neutrino mass spectrum and a normal mass ordering, the upper bound on the absolute neutrino mass is found to be m{sub ν} < (0.83 ± 0.24) eV at the 95% confidence level for a typical galactic supernova at a distance of 10 kpc, where the mean value and standard deviation are shown to account for statistical fluctuations. For comparison, we find that the bound in the Super-Kamiokande experiment is m{sub ν} < (0.94 ± 0.28) eV at the same confidence level. However, the upper bound will be relaxed when the model parameters characterizing the time structure of supernova neutrino fluxes are not exactly known, and when the neutrino mass ordering is inverted.

  10. Self-attraction effect and correction on the T-1 absolute gravimeter

    NASA Astrophysics Data System (ADS)

    Li, Z.; Hu, H.; Wu, K.; Li, G.; Wang, G.; Wang, L. J.

    2015-12-01

    The self-attraction effect (SAE) in an absolute gravimeter is a kind of systematic error due to the gravitation of the instrument to the falling object. This effect depends on the mass distribution of the gravimeter, and is estimated to be a few microgals (1 μGal  =  10-8 m s-2) for the FG5 gravimeter. In this paper, the SAE of a home-made T-1 absolute gravimeter is analyzed and calculated. Most of the stationary components, including the dropping chamber, the laser interferometer, the vibration isolation device and two tripods, are finely modelled, and the related SAEs are computed. In addition, the SAE of the co-falling carriage inside the dropping chamber is carefully calculated because the distance between the falling object and the co-falling carriage varies during the measurement. In order to get the correction of the SAE, two different methods are compared. One is to linearize the SAE curve, the other one is to calculate the perturbed trajectory. The results from these two methods agree with each other within 0.01 μGal. With an uncertainty analysis, the correction of the SAE of the T-1 gravimeter is estimated to be (-1.9  ±  0.1) μGal.

  11. Implications of an absolute simultaneity theory for cosmology and universe acceleration.

    PubMed

    Kipreos, Edward T

    2014-01-01

    An alternate Lorentz transformation, Absolute Lorentz Transformation (ALT), has similar kinematics to special relativity yet maintains absolute simultaneity in the context of a preferred reference frame. In this study, it is shown that ALT is compatible with current experiments to test Lorentz invariance only if the proposed preferred reference frame is locally equivalent to the Earth-centered non-rotating inertial reference frame, with the inference that in an ALT framework, preferred reference frames are associated with centers of gravitational mass. Applying this theoretical framework to cosmological data produces a scenario of universal time contraction in the past. In this scenario, past time contraction would be associated with increased levels of blueshifted light emissions from cosmological objects when viewed from our current perspective. The observation that distant Type Ia supernovae are dimmer than predicted by linear Hubble expansion currently provides the most direct evidence for an accelerating universe. Adjusting for the effects of time contraction on a redshift-distance modulus diagram produces a linear distribution of supernovae over the full redshift spectrum that is consistent with a non-accelerating universe.

  12. Photochirogenesis: Photochemical models on the absolute asymmetric formation of amino acids in interstellar space

    NASA Astrophysics Data System (ADS)

    Meinert, Cornelia; de Marcellus, Pierre; Le Sergeant D'Hendecourt, Louis; Nahon, Laurent; Jones, Nykola C.; Hoffmann, Søren V.; Bredehöft, Jan Hendrik; Meierhenrich, Uwe J.

    2011-10-01

    Proteins of all living organisms including plants, animals, and humans are made up of amino acid monomers that show identical stereochemical L-configuration. Hypotheses for the origin of this symmetry breaking in biomolecules include the absolute asymmetric photochemistry model by which interstellar ultraviolet (UV) circularly polarized light (CPL) induces an enantiomeric excess in chiral organic molecules in the interstellar/circumstellar media. This scenario is supported by a) the detection of amino acids in the organic residues of UV-photo-processed interstellar ice analogues, b) the occurrence of L-enantiomer-enriched amino acids in carbonaceous meteorites, and c) the observation of CPL of the same helicity over large distance scales in the massive star-forming region of Orion. These topics are of high importance in topical biophysical research and will be discussed in this review. Further evidence that amino acids and other molecules of prebiotic interest are asymmetrically formed in space comes from studies on the enantioselective photolysis of amino acids by UV-CPL. Also, experiments have been performed on the absolute asymmetric photochemical synthesis of enantiomer-enriched amino acids from mixtures of astrophysically relevant achiral precursor molecules using UV-circularly polarized photons. Both approaches are based on circular dichroic transitions of amino acids that will be highlighted here as well. These results have strong implications on our current understanding of how life's precursor molecules were possibly built and how life selected the left-handed form of proteinogenic amino acids.

  13. Microteaching at a Distance University.

    ERIC Educational Resources Information Center

    Yule, Ronald M.

    1981-01-01

    Describes the use of microteaching at a distance university as an evaluation method in teacher training. Problems of working with students using this technique are discussed, and possible solutions are suggested. Included are 10 references. (Author/BK)

  14. Distance Learning for Special Populations

    ERIC Educational Resources Information Center

    Bates, Rodger A.

    2012-01-01

    Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…

  15. Graph distance for complex networks

    NASA Astrophysics Data System (ADS)

    Shimada, Yutaka; Hirata, Yoshito; Ikeguchi, Tohru; Aihara, Kazuyuki

    2016-10-01

    Networks are widely used as a tool for describing diverse real complex systems and have been successfully applied to many fields. The distance between networks is one of the most fundamental concepts for properly classifying real networks, detecting temporal changes in network structures, and effectively predicting their temporal evolution. However, this distance has rarely been discussed in the theory of complex networks. Here, we propose a graph distance between networks based on a Laplacian matrix that reflects the structural and dynamical properties of networked dynamical systems. Our results indicate that the Laplacian-based graph distance effectively quantifies the structural difference between complex networks. We further show that our approach successfully elucidates the temporal properties underlying temporal networks observed in the context of face-to-face human interactions.

  16. Equivalency Theory and Distance Education.

    ERIC Educational Resources Information Center

    Simonson, Michael

    1999-01-01

    Discusses distance education and the need for an accepted theory. Highlights include theories of independent study; theory of industrialization of teaching; theory of interaction and communication; and equivalency theory that is based on local control, personalized instruction, and telecommunications. (LRW)

  17. Graph distance for complex networks

    PubMed Central

    Shimada, Yutaka; Hirata, Yoshito; Ikeguchi, Tohru; Aihara, Kazuyuki

    2016-01-01

    Networks are widely used as a tool for describing diverse real complex systems and have been successfully applied to many fields. The distance between networks is one of the most fundamental concepts for properly classifying real networks, detecting temporal changes in network structures, and effectively predicting their temporal evolution. However, this distance has rarely been discussed in the theory of complex networks. Here, we propose a graph distance between networks based on a Laplacian matrix that reflects the structural and dynamical properties of networked dynamical systems. Our results indicate that the Laplacian-based graph distance effectively quantifies the structural difference between complex networks. We further show that our approach successfully elucidates the temporal properties underlying temporal networks observed in the context of face-to-face human interactions. PMID:27725690

  18. Keeping One’s Distance

    PubMed Central

    Williams, Lawrence E.; Bargh, John A.

    2008-01-01

    Current conceptualizations of psychological distance (e.g., construal-level theory) refer to the degree of overlap between the self and some other person, place, or point in time. We propose a complementary view in which perceptual and motor representations of physical distance influence people’s thoughts and feelings without reference to the self, extending research and theory on the effects of distance into domains where construal-level theory is silent. Across four experiments, participants were primed with either spatial closeness or spatial distance by plotting an assigned set of points on a Cartesian coordinate plane. Compared with the closeness prime, the distance prime produced greater enjoyment of media depicting embarrassment (Study 1), less emotional distress from violent media (Study 2), lower estimates of the number of calories in unhealthy food (Study 3), and weaker reports of emotional attachments to family members and hometowns (Study 4). These results support a broader conceptualization of distance-mediated effects on judgment and affect. PMID:18315805

  19. Comb-referenced laser distance interferometer for industrial nanotechnology.

    PubMed

    Jang, Yoon-Soo; Wang, Guochao; Hyun, Sangwon; Kang, Hyun Jay; Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-01-01

    A prototype laser distance interferometer is demonstrated by incorporating the frequency comb of a femtosecond laser for mass-production of optoelectronic devices such as flat panel displays and solar cell devices. This comb-referenced interferometer uses four different wavelengths simultaneously to enable absolute distance measurement with the capability of comprehensive evaluation of the measurement stability and uncertainty. The measurement result reveals that the stability reaches 3.4 nm for a 3.8 m distance at 1.0 s averaging, which further reduces to 0.57 nm at 100 s averaging with a fractional stability of 1.5 × 10(-10). The uncertainty is estimated to be in a 10(-8) level when distance is measured in air due to the inevitable ambiguity in estimating the refractive index, but it can be enhanced to a 10(-10) level in vacuum. PMID:27558016

  20. Comb-referenced laser distance interferometer for industrial nanotechnology

    PubMed Central

    Jang, Yoon-Soo; Wang, Guochao; Hyun, Sangwon; Kang, Hyun Jay; Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-01-01

    A prototype laser distance interferometer is demonstrated by incorporating the frequency comb of a femtosecond laser for mass-production of optoelectronic devices such as flat panel displays and solar cell devices. This comb-referenced interferometer uses four different wavelengths simultaneously to enable absolute distance measurement with the capability of comprehensive evaluation of the measurement stability and uncertainty. The measurement result reveals that the stability reaches 3.4 nm for a 3.8 m distance at 1.0 s averaging, which further reduces to 0.57 nm at 100 s averaging with a fractional stability of 1.5 × 10−10. The uncertainty is estimated to be in a 10−8 level when distance is measured in air due to the inevitable ambiguity in estimating the refractive index, but it can be enhanced to a 10−10 level in vacuum. PMID:27558016

  1. Long-Period Ground Motion Prediction Equations for Relative, Pseudo-Relative and Absolute Velocity Response Spectra in Japan

    NASA Astrophysics Data System (ADS)

    Dhakal, Y. P.; Kunugi, T.; Suzuki, W.; Aoi, S.

    2014-12-01

    Many of the empirical ground motion prediction equations (GMPE) also known as attenuation relations have been developed for absolute acceleration or pseudo relative velocity response spectra. For a small damping, pseudo and absolute acceleration response spectra are nearly identical and hence interchangeable. It is generally known that the relative and pseudo relative velocity response spectra differ considerably at very short or very long periods, and the two are often considered similar at intermediate periods. However, observations show that the period range at which the two spectra become comparable is different from site to site. Also, the relationship of the above two types of velocity response spectra with absolute velocity response spectra are not discussed well in literature. The absolute velocity response spectra are the peak values of time histories obtained by adding the ground velocities to relative velocity response time histories at individual natural periods. There exists many tall buildings on huge and deep sedimentary basins such as the Kanto basin, and the number of such buildings is growing. Recently, Japan Meteorological Agency (JMA) has proposed four classes of long-period ground motion intensity (http://www.data.jma.go.jp/svd/eew/data/ltpgm/) based on absolute velocity response spectra, which correlate to the difficulty of movement of people in tall buildings. As the researchers are using various types of response spectra for long-period ground motions, it is important to understand the relationships between them to take appropriate measures for disaster prevention applications. In this paper, we, therefore, obtain and discuss the empirical attenuation relationships using the same functional forms for the three types of velocity response spectra computed from observed strong motion records from moderate to large earthquakes in relation to JMA magnitude, hypocentral distance, sediment depths, and AVS30 as predictor variables at periods between

  2. Mathematical Model for Absolute Magnetic Measuring Systems in Industrial Applications

    NASA Astrophysics Data System (ADS)

    Fügenschuh, Armin; Fügenschuh, Marzena; Ludszuweit, Marina; Mojsic, Aleksandar; Sokół, Joanna

    2015-09-01

    Scales for measuring systems are either based on incremental or absolute measuring methods. Incremental scales need to initialize a measurement cycle at a reference point. From there, the position is computed by counting increments of a periodic graduation. Absolute methods do not need reference points, since the position can be read directly from the scale. The positions on the complete scales are encoded using two incremental tracks with different graduation. We present a new method for absolute measuring using only one track for position encoding up to micrometre range. Instead of the common perpendicular magnetic areas, we use a pattern of trapezoidal magnetic areas, to store more complex information. For positioning, we use the magnetic field where every position is characterized by a set of values measured by a hall sensor array. We implement a method for reconstruction of absolute positions from the set of unique measured values. We compare two patterns with respect to uniqueness, accuracy, stability and robustness of positioning. We discuss how stability and robustness are influenced by different errors during the measurement in real applications and how those errors can be compensated.

  3. Absolute Value Inequalities: High School Students' Solutions and Misconceptions

    ERIC Educational Resources Information Center

    Almog, Nava; Ilany, Bat-Sheva

    2012-01-01

    Inequalities are one of the foundational subjects in high school math curricula, but there is a lack of academic research into how students learn certain types of inequalities. This article fills part of the research gap by presenting the findings of a study that examined high school students' methods of approaching absolute value inequalities,…

  4. Individual Differences in Absolute and Relative Metacomprehension Accuracy

    ERIC Educational Resources Information Center

    Maki, Ruth H.; Shields, Micheal; Wheeler, Amanda Easton; Zacchilli, Tammy Lowery

    2005-01-01

    The authors investigated absolute and relative metacomprehension accuracy as a function of verbal ability in college students. Students read hard texts, revised texts, or a mixed set of texts. They then predicted their performance, took a multiple-choice test on the texts, and made posttest judgments about their performance. With hard texts,…

  5. Ion chambers simplify absolute intensity measurements in the vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Sampson, J. A. R.

    1966-01-01

    Single or double ion chamber technique measures absolute radiation intensities in the extreme vacuum ultraviolet region of the spectrum. The ion chambers use rare gases as the ion carrier. Photon absorbed by the gas creates one ion pair so a measure of these is a measure of the number of incident photons.

  6. Lyman alpha SMM/UVSP absolute calibration and geocoronal correction

    NASA Technical Reports Server (NTRS)

    Fontenla, Juan M.; Reichmann, Edwin J.

    1987-01-01

    Lyman alpha observations from the Ultraviolet Spectrometer Polarimeter (UVSP) instrument of the Solar Maximum Mission (SMM) spacecraft were analyzed and provide instrumental calibration details. Specific values of the instrument quantum efficiency, Lyman alpha absolute intensity, and correction for geocoronal absorption are presented.

  7. An improved generalized Newton method for absolute value equations.

    PubMed

    Feng, Jingmei; Liu, Sanyang

    2016-01-01

    In this paper, we suggest and analyze an improved generalized Newton method for solving the NP-hard absolute value equations [Formula: see text] when the singular values of A exceed 1. We show that the global and local quadratic convergence of the proposed method. Numerical experiments show the efficiency of the method and the high accuracy of calculation. PMID:27462490

  8. Absolute configurations of zingiberenols isolated from ginger (Zingiber officinale) rhizomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sesquiterpene alcohol zingiberenol, or 1,10-bisaboladien-3-ol, was isolated some time ago from ginger, Zingiber officinale, rhizomes, but its absolute configuration had not been determined. With three chiral centers present in the molecule, zingiberenol can exist in eight stereoisomeric forms. ...

  9. Series that Converge Absolutely but Don't Converge

    ERIC Educational Resources Information Center

    Kantrowitz, Robert; Schramm, Michael

    2012-01-01

    If a series of real numbers converges absolutely, then it converges. The usual proof requires completeness in the form of the Cauchy criterion. Failing completeness, the result is false. We provide examples of rational series that illustrate this point. The Cantor set appears in connection with one of the examples.

  10. Absolute calibration in the 1750 - 3350 A region

    NASA Technical Reports Server (NTRS)

    Strongylis, G. J.; Bohlin, R. C.

    1977-01-01

    The absolute flux measurements in the rocket ultraviolet made by Bohlin, Frimout, and Lillie (BFL) are revised using a more correct treatment of the air extinction that enters the air calibration of their instrument. The absorption by molecular oxygen and ozone, Rayleigh scattering, and extinction by aerosols is tabulated for general use in ultraviolet calibrations performed in air. The revised absolute flux of eta UMa and final fluxes for alpha Lyr and zeta Oph are presented in the 1750-3350 A region. The absolute flux of the star eta UMa is compared to four other independent determinations in the 1200-3400 A region and a maximum difference of 35% is found near 1500 A between the OAO-2 and Apollo 17 fluxes. The rocket measurements of BFL, the ANS and TD-1 satellite data, and the Apollo 17 data are compared to the ultraviolet fluxes from the OAO-2, demonstrating a photometric reproducibility of about + or - 3 percent. Therefore, all four sets of spectrophotometry can be reduced to a common absolute scale.

  11. Europe's Other Poverty Measures: Absolute Thresholds Underlying Social Assistance

    ERIC Educational Resources Information Center

    Bavier, Richard

    2009-01-01

    The first thing many learn about international poverty measurement is that European nations apply a "relative" poverty threshold and that they also do a better job of reducing poverty. Unlike the European model, the "absolute" U.S. poverty threshold does not increase in real value when the nation's standard of living rises, even though it is…

  12. Analysis of standard reference materials by absolute INAA

    SciTech Connect

    Heft, R.E.; Koszykowski, R.F.

    1981-07-01

    Three standard reference materials, flyash, soil, and ASI 4340 steel, were analyzed by a method of absolute instrumental neutron activation analysis (INAA). Two different light water pool-type reactors were used to produce equivalent analytical results even though the epithermal to thermal flux ratio in one reactor was higher than that in the other by a factor of two.

  13. Absolute calibration of Landsat instruments using the moon.

    USGS Publications Warehouse

    Kieffer, H.H.; Wildey, R.L.

    1985-01-01

    A lunar observation by Landsat could provide improved radiometric and geometric calibration of both the Thematic Mapper and the Multispectral Scanner in terms of absolute radiometry, determination of the modulation transfer function, and sensitivity to scattered light. A pitch of the spacecraft would be required. -Authors

  14. Urey: to measure the absolute age of Mars

    NASA Technical Reports Server (NTRS)

    Randolph, J. E.; Plescia, J.; Bar-Cohen, Y.; Bartlett, P.; Bickler, D.; Carlson, R.; Carr, G.; Fong, M.; Gronroos, H.; Guske, P. J.; Herring, M.; Javadi, H.; Johnson, D. W.; Larson, T.; Malaviarachchi, K.; Sherrit, S.; Stride, S.; Trebi-Ollennu, A.; Warwick, R.

    2003-01-01

    UREY, a proposed NASA Mars Scout mission will, for the first time, measure the absolute age of an identified igneous rock formation on Mars. By extension to relatively older and younger rock formations dated by remote sensing, these results will enable a new and better understanding of Martian geologic history.

  15. Is There a Rule of Absolute Neutralization in Nupe?

    ERIC Educational Resources Information Center

    Krohn, Robert

    1975-01-01

    A previously prosed rule of absolute neutralization (merging underlying low vowels) is eliminated in an alternative analysis including instead a rule that "breaks" the feature matrix of certain low vowels and redistributes the features of each vowel as a sequence of vowel-like transition plus (a). (Author/RM)

  16. Absolute Radiometer for Reproducing the Solar Irradiance Unit

    NASA Astrophysics Data System (ADS)

    Sapritskii, V. I.; Pavlovich, M. N.

    1989-01-01

    A high-precision absolute radiometer with a thermally stabilized cavity as receiving element has been designed for use in solar irradiance measurements. The State Special Standard of the Solar Irradiance Unit has been built on the basis of the developed absolute radiometer. The Standard also includes the sun tracking system and the system for automatic thermal stabilization and information processing, comprising a built-in microcalculator which calculates the irradiance according to the input program. During metrological certification of the Standard, main error sources have been analysed and the non-excluded systematic and accidental errors of the irradiance-unit realization have been determined. The total error of the Standard does not exceed 0.3%. Beginning in 1984 the Standard has been taking part in a comparison with the Å 212 pyrheliometer and other Soviet and foreign standards. In 1986 it took part in the international comparison of absolute radiometers and standard pyrheliometers of socialist countries. The results of the comparisons proved the high metrological quality of this Standard based on an absolute radiometer.

  17. Relative versus Absolute Stimulus Control in the Temporal Bisection Task

    ERIC Educational Resources Information Center

    de Carvalho, Marilia Pinhiero; Machado, Armando

    2012-01-01

    When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s,…

  18. Multifrequency continuous wave terahertz spectroscopy for absolute thickness determination

    SciTech Connect

    Scheller, Maik; Baaske, Kai; Koch, Martin

    2010-04-12

    We present a tunable multifrequency continuous wave terahertz spectrometer based on two laser diodes, photoconductive antennas, and a coherent detection scheme. The system is employed to determine the absolute thickness of samples utilizing a proposed synthetic difference frequency method to circumvent the 2pi uncertainty known from conventional photomixing systems while preserving a high spatial resolution.

  19. Absolute Interrogative Intonation Patterns in Buenos Aires Spanish

    ERIC Educational Resources Information Center

    Lee, Su Ar

    2010-01-01

    In Spanish, each uttered phrase, depending on its use, has one of a variety of intonation patterns. For example, a phrase such as "Maria viene manana" "Mary is coming tomorrow" can be used as a declarative or as an absolute interrogative (a yes/no question) depending on the intonation pattern that a speaker produces. Patterns of usage also…

  20. Measuring Cosmic Distances with Stellar Heart Beats

    NASA Astrophysics Data System (ADS)

    2004-10-01

    .5 days, a fairly wide interval and an important advantage to properly calibrate the Period-Luminosity relation. The distances to four of the stars (Eta Aql, W Sgr, Beta Dor and L Car) were derived using the interferometric Baade-Wesselink method, as their pulsation is detected by the VLTI. ESO PR Photo 30c/04 shows the angular diameter measurements and the fitted radius curve of L Car (P = 35.5 days); this measures its distance with a relative precision better than 5%. For the remaining three objects of the sample (X Sgr, Zeta Gem and Y Oph), a hybrid method was applied to derive their distances, based on their average angular diameter and pre-existing estimations of their linear diameters. The new calibration ESO PR Photo 30d/04 ESO PR Photo 30d/04 Title [Preview - JPEG: 400 x 365 pix - 80k] [Normal - JPEG: 800 x 730 pix - 168k] Caption: ESO PR Photo 30d/04 represents the Period-Luminosity relation in the V band, as deduced from the interferometric observations of Cepheids and the HST parallax measurement of Delta Cep. The green line is the fitted P-L relation, assuming the slope from previous authors (Gieren et al.; 1998, ApJ, 496, 17). The agreement between the model and the measurements is excellent, in particular for the high-precision measurements of Delta Cep and L Car. Combining the distances measured by this programme with the apparent magnitudes of the stars, the astronomers determined the absolute magnitude (intrinsic brightness) of these stars and arrived at a very precise calibration of the zero-point of the Period-Luminosity relation (assuming the slope from previous work). It turned out that this new and independently derived value of the zero-point is exactly the same as the one obtained during previous work based on a large number of relatively low-precision Cepheid distance measurements by the ESA Hipparcos astrometric satellite. The agreement between these two independent, geometrical calibrations is remarkable and greatly increases the confidence in

  1. Absolute Gravity Datum in the Age of Cold Atom Gravimeters

    NASA Astrophysics Data System (ADS)

    Childers, V. A.; Eckl, M. C.

    2014-12-01

    The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant

  2. GNSS Absolute Antenna Calibration at the National Geodetic Survey

    NASA Astrophysics Data System (ADS)

    Mader, G. L.; Bilich, A. L.; Geoghegan, C.

    2011-12-01

    Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna models and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these models into analysis software. To help meet the needs of the high-precision GNSS community, the National Geodetic Survey (NGS) now operates an absolute antenna calibration facility. Located in Corbin, Virginia, this facility uses field measurements and actual GNSS satellite signals to quantitatively determine the carrier phase advance/delay introduced by the antenna element. The NGS facility was built to serve traditional NGS constituents such as the surveying and geodesy communities, however calibration services are open and available to all GNSS users as the calibration schedule permits. All phase center patterns computed by this facility will be publicly available and disseminated in both the ANTEX and NGS formats. We describe the NGS calibration facility, and discuss the observation models and strategy currently used to generate NGS absolute calibrations. We demonstrate that NGS absolute phase center variation (PCV) patterns are consistent with published values determined by other absolute antenna calibration facilities, and compare absolute calibrations to the traditional NGS relative calibrations.

  3. Social interaction distance and stratification.

    PubMed

    Bottero, Wendy; Prandy, Kenneth

    2003-06-01

    There have been calls from several sources recently for a renewal of class analysis that would encompass social and cultural, as well as economic elements. This paper explores a tradition in stratification that is founded on this idea: relational or social distance approaches to mapping hierarchy and inequality which theorize stratification as a social space. The idea of 'social space' is not treated as a metaphor of hierarchy nor is the nature of the structure determined a priori. Rather, the space is identified by mapping social interactions. Exploring the nature of social space involves mapping the network of social interaction--patterns of friendship, partnership and cultural similarity--which gives rise to relations of social closeness and distance. Differential association has long been seen as the basis of hierarchy, but the usual approach is first to define a structure composed of a set of groups and then to investigate social interaction between them. Social distance approaches reverse this, using patterns of interaction to determine the nature of the structure. Differential association can be seen as a way of defining proximity within a social space, from the distances between social groups, or between social groups and social objects (such as lifestyle items). The paper demonstrates how the very different starting point of social distance approaches also leads to strikingly different theoretical conclusions about the nature of stratification and inequality.

  4. Perceived distance during golf putting.

    PubMed

    Hasegawa, Yumiko; Koyama, Satoshi; Inomata, Kimihiro

    2013-12-01

    This study examined the effect of anxiety states on the relationship between golf-putting distance and performance in an environment requiring high movement accuracy. Twenty-three amateur golfers attempted 15 putts at each of three putting distances, 1.25, 1.50, and 1.75m, under conditions characterized by both control demands and pressure. All attempts were recorded, and kinematic features were analyzed. Under conditions involving an audience and a monetary reward, the mean score on the State-Trait Anxiety Inventory Y-1 and the mean heart rate increased by 14 points and 11bpm, respectively. We grouped participants on an a posteriori basis using the median split. The backswing of high-anxiety performers shortened, the downswing speed declined, and the relative time to peak club-head velocity changed when putting under pressure from 1.25m. In contrast, no change in backswing or relative time to peak velocity was observed in low-anxiety performers, although impact velocity increased under this condition. These results indicate that the degree to which both low- and high-anxiety golfers were anxious about failure affected motor control at the 1.25-m distance, suggesting that a distortion in perceived distance may result from the interaction between putting distance and anxiety related to failure during golf putting.

  5. Measuring distances between complex networks

    NASA Astrophysics Data System (ADS)

    Andrade, Roberto F. S.; Miranda, José G. V.; Pinho, Suani T. R.; Lobão, Thierry Petit

    2008-08-01

    A previously introduced concept of higher order neighborhoods in complex networks, [R.F.S. Andrade, J.G.V. Miranda, T.P. Lobão, Phys. Rev. E 73 (2006) 046101] is used to define a distance between networks with the same number of nodes. With such measure, expressed in terms of the matrix elements of the neighborhood matrices of each network, it is possible to compare, in a quantitative way, how far apart in the space of neighborhood matrices two networks are. The distance between these matrices depends on both the network topologies and the adopted node numberings. While the numbering of one network is fixed, a Monte Carlo algorithm is used to find the best numbering of the other network, in the sense that it minimizes the distance between the matrices. The minimal value found for the distance reflects differences in the neighborhood structures of the two networks that arise only from distinct topologies. This procedure ends up by providing a projection of the first network on the pattern of the second one. Examples are worked out allowing for a quantitative comparison for distances among distinct networks, as well as among distinct realizations of random networks.

  6. Individual differences in distance perception.

    PubMed

    Jackson, Russell E

    2009-05-01

    Distance perception is among the most pervasive mental phenomena and the oldest research topics in behavioural science. However, we do not understand well the most pervasive finding of distance perception research, that of large individual differences. There are large individual differences in acrophobia (fear of heights), which we commonly assume consists of an abnormal fear of stimuli perceived normally. Evolved navigation theory (ENT) instead suggests that acrophobia consists of a more normal fear of stimuli perceived abnormally. ENT suggests that distance perception individual differences produce major components of acrophobia. Acrophobia tested over a broad range in the present study predicted large individual differences in distance estimation of surfaces that could produce falls. This fear of heights correlated positively with distance estimates of a vertical surface-even among non-acrophobic individuals at no risk of falling and without knowledge of being tested for acrophobia. Acrophobia score predicted magnitude of the descent illusion, which is thought to reflect the risk of falling. These data hold important implications in environmental navigation, clinical aetiology and the evolution of visual systems.

  7. Perceived distance during golf putting.

    PubMed

    Hasegawa, Yumiko; Koyama, Satoshi; Inomata, Kimihiro

    2013-12-01

    This study examined the effect of anxiety states on the relationship between golf-putting distance and performance in an environment requiring high movement accuracy. Twenty-three amateur golfers attempted 15 putts at each of three putting distances, 1.25, 1.50, and 1.75m, under conditions characterized by both control demands and pressure. All attempts were recorded, and kinematic features were analyzed. Under conditions involving an audience and a monetary reward, the mean score on the State-Trait Anxiety Inventory Y-1 and the mean heart rate increased by 14 points and 11bpm, respectively. We grouped participants on an a posteriori basis using the median split. The backswing of high-anxiety performers shortened, the downswing speed declined, and the relative time to peak club-head velocity changed when putting under pressure from 1.25m. In contrast, no change in backswing or relative time to peak velocity was observed in low-anxiety performers, although impact velocity increased under this condition. These results indicate that the degree to which both low- and high-anxiety golfers were anxious about failure affected motor control at the 1.25-m distance, suggesting that a distortion in perceived distance may result from the interaction between putting distance and anxiety related to failure during golf putting. PMID:24050839

  8. Virtual bioinformatics distance learning suite*.

    PubMed

    Tolvanen, Martti; Vihinen, Mauno

    2004-05-01

    Distance learning as a computer-aided concept allows students to take courses from anywhere at any time. In bioinformatics, computers are needed to collect, store, process, and analyze massive amounts of biological and biomedical data. We have applied the concept of distance learning in virtual bioinformatics to provide university course material over the Internet. Currently, we provide two fully computer-based courses, "Introduction to Bioinformatics" and "Bioinformatics in Functional Genomics." Here we will discuss the application of distance learning in bioinformatics training and our experiences gained during the 3 years that we have run the courses, with about 400 students from a number of universities. The courses are available at bioinf.uta.fi.

  9. Distance Education at Arm's Length: Outsourcing of Distance Education Marking.

    ERIC Educational Resources Information Center

    Smith, Erica; Coombe, Kennece

    Two research projects focused on use of casual markers (graders) for correcting and grading distance education (DE) students' work. A Charles Sturt University project convened focus groups of DE students, casual DE markers, and lecturers who "managed" markers to uncover concerns. University of South Australia research focused on pedagogical issues…

  10. Using Web-Based Distance Learning to Reduce Cultural Distance

    ERIC Educational Resources Information Center

    Wong, L. Fai; Trinidad, S. G.

    2004-01-01

    In recent years, Web-based distance learning (WBDL) systems have become a popular learning environment for many western learners. While it has been established as an effective learning alternative, WBDL is not flourishing in Hong Kong as expected. This paper proposes that this is because Hong Kong students are not trained to learn independently…

  11. Statistical Efficiency in Distance Sampling

    PubMed Central

    Clark, Robert Graham

    2016-01-01

    Distance sampling is a technique for estimating the abundance of animals or other objects in a region, allowing for imperfect detection. This paper evaluates the statistical efficiency of the method when its assumptions are met, both theoretically and by simulation. The theoretical component of the paper is a derivation of the asymptotic variance penalty for the distance sampling estimator arising from uncertainty about the unknown detection parameters. This asymptotic penalty factor is tabulated for several detection functions. It is typically at least 2 but can be much higher, particularly for steeply declining detection rates. The asymptotic result relies on a model which makes the strong assumption that objects are uniformly distributed across the region. The simulation study relaxes this assumption by incorporating over-dispersion when generating object locations. Distance sampling and strip transect estimators are calculated for simulated data, for a variety of overdispersion factors, detection functions, sample sizes and strip widths. The simulation results confirm the theoretical asymptotic penalty in the non-overdispersed case. For a more realistic overdispersion factor of 2, distance sampling estimation outperforms strip transect estimation when a half-normal distance function is correctly assumed, confirming previous literature. When the hazard rate model is correctly assumed, strip transect estimators have lower mean squared error than the usual distance sampling estimator when the strip width is close enough to its optimal value (± 75% when there are 100 detections; ± 50% when there are 200 detections). Whether the ecologist can set the strip width sufficiently accurately will depend on the circumstances of each particular study. PMID:26950934

  12. Statistical Efficiency in Distance Sampling.

    PubMed

    Clark, Robert Graham

    2016-01-01

    Distance sampling is a technique for estimating the abundance of animals or other objects in a region, allowing for imperfect detection. This paper evaluates the statistical efficiency of the method when its assumptions are met, both theoretically and by simulation. The theoretical component of the paper is a derivation of the asymptotic variance penalty for the distance sampling estimator arising from uncertainty about the unknown detection parameters. This asymptotic penalty factor is tabulated for several detection functions. It is typically at least 2 but can be much higher, particularly for steeply declining detection rates. The asymptotic result relies on a model which makes the strong assumption that objects are uniformly distributed across the region. The simulation study relaxes this assumption by incorporating over-dispersion when generating object locations. Distance sampling and strip transect estimators are calculated for simulated data, for a variety of overdispersion factors, detection functions, sample sizes and strip widths. The simulation results confirm the theoretical asymptotic penalty in the non-overdispersed case. For a more realistic overdispersion factor of 2, distance sampling estimation outperforms strip transect estimation when a half-normal distance function is correctly assumed, confirming previous literature. When the hazard rate model is correctly assumed, strip transect estimators have lower mean squared error than the usual distance sampling estimator when the strip width is close enough to its optimal value (± 75% when there are 100 detections; ± 50% when there are 200 detections). Whether the ecologist can set the strip width sufficiently accurately will depend on the circumstances of each particular study.

  13. Long working distance interference microscope

    DOEpatents

    Sinclair, Michael B.; DeBoer, Maarten P.; Smith, Norman F.

    2004-04-13

    Disclosed is a long working distance interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. The long working distance of 10-30 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-D height profiles of MEMS test structures to be acquired across an entire wafer. A well-matched pair of reference/sample objectives is not required, significantly reducing the cost of this microscope, as compared to a Linnik microinterferometer.

  14. Entropy distance: New quantum phenomena

    SciTech Connect

    Weis, Stephan; Knauf, Andreas

    2012-10-15

    We study a curve of Gibbsian families of complex 3 Multiplication-Sign 3-matrices and point out new features, absent in commutative finite-dimensional algebras: a discontinuous maximum-entropy inference, a discontinuous entropy distance, and non-exposed faces of the mean value set. We analyze these problems from various aspects including convex geometry, topology, and information geometry. This research is motivated by a theory of infomax principles, where we contribute by computing first order optimality conditions of the entropy distance.

  15. 49 CFR 236.741 - Distance, stopping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Distance, stopping. 236.741 Section 236.741... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such... stop....

  16. 49 CFR 236.741 - Distance, stopping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Distance, stopping. 236.741 Section 236.741... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such... stop....

  17. 49 CFR 236.741 - Distance, stopping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Distance, stopping. 236.741 Section 236.741... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such... stop....

  18. 49 CFR 236.741 - Distance, stopping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Distance, stopping. 236.741 Section 236.741... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such... stop....

  19. 49 CFR 236.741 - Distance, stopping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Distance, stopping. 236.741 Section 236.741... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such... stop....

  20. Absolute Configurations of Zingiberenols Isolated from Ginger (Zingiber officinale) Rhizomes.

    PubMed

    Khrimian, Ashot; Shirali, Shyam; Guzman, Filadelfo

    2015-12-24

    Two stereoisomeric zingiberenols in ginger were identified as (3R,6R,7S)-1,10-bisaboladien-3-ol (2) and (3S,6R,7S)-1,10-bisaboladien-3-ol (5). Absolute configurations were assigned by utilizing 1,10-bisaboladien-3-ol stereoisomers and two gas-chromatography columns: a 25 m Hydrodex-β-6TBDM and 60 m DB-5MS. The C-6 and C-7 absolute configurations in both zingiberenols match those of zingiberene present abundantly in ginger rhizomes. Interestingly, zingiberenol 2 has recently been identified as a male-produced sex pheromone of the rice stink bug, Oebalus poecilus, thus indicating that ginger plants may be a potential source of the sex pheromone of this bug.

  1. In-flight Absolute Radiometric Calibration of the Thematic Mapper

    NASA Technical Reports Server (NTRS)

    Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, D.; Savage, R. K.

    1984-01-01

    The Thematic Mapper (TM) multispectral scanner system was placed into Earth orbit on July 16, 1982, as part of NASA's LANDSAT 4 payload. To determine temporal changes of the absolute radiometric calibration of the entire system in flight, spectroradiometric measurements of the ground and the atmosphere are made simultaneously with TM image acquisitions over the White Sands, New Mexico area. By entering the measured values into an atmospheric radiative transfer program, the radiance levels at the entrance pupil of the TM in four of the TM spectral bands are determined. These levels are compared to the output digital counts from the detectors that sampled the radiometrically measured ground area, thus providing an absolute radiometric calibration of the entire TM system utilizing those detectors. By reference to an adjacent, larger uniform area, the calibration is extended to all 16 detectors in each of the three bands.

  2. In-flight absolute radiometric calibration of the thematic mapper

    NASA Technical Reports Server (NTRS)

    Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, R. D.; Savage, R. K.

    1984-01-01

    In order to determine temporal changes of the absolute radiometric calibration of the entire TM system in flight spectroradiometric measurements of the ground and the atmosphere were made simultaneously with TM image collections over the White Sands, New Mexico area. By entering the measured values in an atmospheric radiative transfer program, the radiance levels in four of the spectral bands of the TM were determined, band 1:0.45 to 0.52 micrometers, band 2:0.53 to 0.61 micrometers band 3:0.62 to 0.70 micrometers and 4:0.78 to 0.91 micrometers. These levels were compared to the output digital counts from the detectors that sampled the radiometrically measured ground area, thus providing an absolute radiometric calibration of the entire TM system utilizing those detectors.

  3. In-flight absolute radiometric calibration of the Thematic Mapper

    NASA Technical Reports Server (NTRS)

    Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, R. D.; Savage, R. K.

    1984-01-01

    In order to determine temporal changes of the absolute radiometric calibration of the entire TM system in flight spectroradiometric measurements of the ground and the atmosphere were made simultaneously with TM image collections over the White Sands, NM area. By entering the measured values in an atmospheric radiative transfer program, the radiance levels in four of the spectral bands of the TM were determined, band 1: 0.45 to 0.52 micrometers, band 2: 0.53 to 0.61 micrometers, band 3: 0.62 to 0.70 micrometers, and 4: 0.78 to 0.91 micrometers. These levels were compared to the output digital counts from the detectors that sampled the radiometrically measured ground area, thus providing an absolute radiometric calibration of the entire TM system utilizing those detectors. Previously announced in STAR as N84-15633

  4. Absolute concentration measurements inside a jet plume using video digitization

    NASA Astrophysics Data System (ADS)

    Vauquelin, O.

    An experimental system based on digitized video image analysis is used to measure the local value of the concentration inside a plume. Experiments are carried out in a wind-tunnel for a smoke-seeded turbulent jet plume illuminated with a laser beam. Each test is filmed, subsequently video images are digitized and analysed in order to determine the smoke absolute concentration corresponding to each pixel gray level. This non-intrusive measurement technique is first calibrated and different laws connecting gray level to concentration are established. As a first application, concentration measurements are made inside a turbulent jet plume and compared with measurements conducted using a classic gas analysis method. We finally present and discuss the possibilities offered for the measurements of absolute concentration fluctuations.

  5. Absolute limit on rotation of gravitationally bound stars

    NASA Astrophysics Data System (ADS)

    Glendenning, N. K.

    1994-03-01

    The authors seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein's theory of relativity, Le Chatelier's principle, causality, and a low-density equation of state, uncertainties which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass-shedding would occur, is 0.33 ms for a M = 1.442 solar mass neutron star (the mass of PSR1913+16). If the limit were found to be broken by any pulsar, it would signal that the confined hadronic phase of ordinary nucleons and nuclei is only metastable.

  6. Absolute limit on rotation of gravitationally bound stars

    SciTech Connect

    Glendenning, N.K.

    1994-03-01

    The authors seek an absolute limit on the rotational period for a neutron star as a function of its mass, based on the minimal constraints imposed by Einstein`s theory of relativity, Le Chatelier`s principle, causality and a low-density equation of state, uncertainties which can be evaluated as to their effect on the result. This establishes a limiting curve in the mass-period plane below which no pulsar that is a neutron star can lie. For example, the minimum possible Kepler period, which is an absolute limit on rotation below which mass-shedding would occur, is 0.33 ms for a M = 1.442 M{circle_dot} neutron star (the mass of PSR1913+16). If the limit were found to be broken by any pulsar, it would signal that the confined hadronic phase of ordinary nucleons and nuclei is only metastable, an extraordinary conclusion.

  7. Henry More and the development of absolute time.

    PubMed

    Thomas, Emily

    2015-12-01

    This paper explores the nature, development and influence of the first English account of absolute time, put forward in the mid-seventeenth century by the 'Cambridge Platonist' Henry More. Against claims in the literature that More does not have an account of time, this paper sets out More's evolving account and shows that it reveals the lasting influence of Plotinus. Further, this paper argues that More developed his views on time in response to his adoption of Descartes' vortex cosmology and cosmogony, providing new evidence of More's wider project to absorb Cartesian natural philosophy into his Platonic metaphysics. Finally, this paper argues that More should be added to the list of sources that later English thinkers - including Newton and Samuel Clarke - drew on in constructing their absolute accounts of time. PMID:26568082

  8. Precision goniometer equipped with a 22-bit absolute rotary encoder.

    PubMed

    Xiaowei, Z; Ando, M; Jidong, W

    1998-05-01

    The calibration of a compact precision goniometer equipped with a 22-bit absolute rotary encoder is presented. The goniometer is a modified Huber 410 goniometer: the diffraction angles can be coarsely generated by a stepping-motor-driven worm gear and precisely interpolated by a piezoactuator-driven tangent arm. The angular accuracy of the precision rotary stage was evaluated with an autocollimator. It was shown that the deviation from circularity of the rolling bearing utilized in the precision rotary stage restricts the angular positioning accuracy of the goniometer, and results in an angular accuracy ten times larger than the angular resolution of 0.01 arcsec. The 22-bit encoder was calibrated by an incremental rotary encoder. It became evident that the accuracy of the absolute encoder is approximately 18 bit due to systematic errors.

  9. Determination of absolute internal conversion coefficients using the SAGE spectrometer

    NASA Astrophysics Data System (ADS)

    Sorri, J.; Greenlees, P. T.; Papadakis, P.; Konki, J.; Cox, D. M.; Auranen, K.; Partanen, J.; Sandzelius, M.; Pakarinen, J.; Rahkila, P.; Uusitalo, J.; Herzberg, R.-D.; Smallcombe, J.; Davies, P. J.; Barton, C. J.; Jenkins, D. G.

    2016-03-01

    A non-reference based method to determine internal conversion coefficients using the SAGE spectrometer is carried out for transitions in the nuclei of 154Sm, 152Sm and 166Yb. The Normalised-Peak-to-Gamma method is in general an efficient tool to extract internal conversion coefficients. However, in many cases the required well-known reference transitions are not available. The data analysis steps required to determine absolute internal conversion coefficients with the SAGE spectrometer are presented. In addition, several background suppression methods are introduced and an example of how ancillary detectors can be used to select specific reaction products is given. The results obtained for ground-state band E2 transitions show that the absolute internal conversion coefficients can be extracted using the methods described with a reasonable accuracy. In some cases of less intense transitions only an upper limit for the internal conversion coefficient could be given.

  10. Flow rate calibration for absolute cell counting rationale and design.

    PubMed

    Walker, Clare; Barnett, David

    2006-05-01

    There is a need for absolute leukocyte enumeration in the clinical setting, and accurate, reliable (and affordable) technology to determine absolute leukocyte counts has been developed. Such technology includes single platform and dual platform approaches. Derivations of these counts commonly incorporate the addition of a known number of latex microsphere beads to a blood sample, although it has been suggested that the addition of beads to a sample may only be required to act as an internal quality control procedure for assessing the pipetting error. This unit provides the technical details for undertaking flow rate calibration that obviates the need to add reference beads to each sample. It is envisaged that this report will provide the basis for subsequent clinical evaluations of this novel approach. PMID:18770842

  11. Enumeration of absolute cell counts using immunophenotypic techniques.

    PubMed

    Mandy, F; Brando, B

    2001-05-01

    Absolute counting of cells or cell subsets has a number of significant clinical applications: monitoring the disease status of HIV-infected patients, enumerating residual white blood cells in leukoreduced blood products, and assessing immunodeficiency in a variety of situations. The single-platform method (flow cytometry alone) has emerged as the method of choice for absolute cell enumeration. This technology counts only the cells of interest in a precisely determined blood volume. Exact cell identification is accomplished by a logical electronic gating algorithm capable of identifying lineage-specific immunofluorescent markers. Exclusion of unwanted cells is automatic. This extensive and detailed unit presents protocols for both volumetric and flow-rate determination of residual white blood cells and of leukocyte subsets. PMID:18770719

  12. Proposal for an absolute, atomic definition of mass

    NASA Astrophysics Data System (ADS)

    Wignall, J. W. G.

    1991-11-01

    It is proposed that the mass of a particle be defined absolutely as its de Broglie frequency, measured as the mean de Broglie wavelength of the particle when it has a mean speed (v) and Lorentz factor (gamma); the masses of systems too large to have a measurable de Broglie wavelength mean are then to be derived by specifying the usual inertial and additive properties of mass. This definition avoids the use of an arbitrary macroscopic standard such as the prototype kilogram, and, if present theory is correct, does not even require the choice of a specific particle as a mass standard. Suggestions are made as to how this absolute mass can be realized and measured at the macroscopic level and, finally, some comments are made on the effect of the new definition on the form of the equations of physics.

  13. Simultaneously improving the sensitivity and absolute accuracy of CPT magnetometer.

    PubMed

    Liang, Shang-Qing; Yang, Guo-Qing; Xu, Yun-Fei; Lin, Qiang; Liu, Zhi-Heng; Chen, Zheng-Xiang

    2014-03-24

    A new method to improve the sensitivity and absolute accuracy simultaneously for coherent population trapping (CPT) magnetometer based on the differential detection method is presented. Two modulated optical beams with orthogonal circular polarizations are applied, in one of which two magnetic resonances are excited simultaneously by modulating a 3.4GHz microwave with Larmor frequency. When a microwave frequency shift is introduced, the difference in the power transmitted through the cell in each beam shows a low noise resonance. The sensitivity of 2pT/Hz @ 10Hz is achieved. Meanwhile, the absolute accuracy of ± 0.5nT within the magnetic field ranging from 20000nT to 100000nT is realized.

  14. Absolute phase effects on CPMG-type pulse sequences

    NASA Astrophysics Data System (ADS)

    Mandal, Soumyajit; Oh, Sangwon; Hürlimann, Martin D.

    2015-12-01

    We describe and analyze the effects of transients within radio-frequency (RF) pulses on multiple-pulse NMR measurements such as the well-known Carr-Purcell-Meiboom-Gill (CPMG) sequence. These transients are functions of the absolute RF phases at the beginning and end of the pulse, and are thus affected by the timing of the pulse sequence with respect to the period of the RF waveform. Changes in transients between refocusing pulses in CPMG-type sequences can result in signal decay, persistent oscillations, changes in echo shape, and other effects. We have explored such effects by performing experiments in two different low-frequency NMR systems. The first uses a conventional tuned-and-matched probe circuit, while the second uses an ultra-broadband un-tuned or non-resonant probe circuit. We show that there are distinct differences between the absolute phase effects in these two systems, and present simple models that explain these differences.

  15. Absolute magnitude calibration using trigonometric parallax - Incomplete, spectroscopic samples

    NASA Technical Reports Server (NTRS)

    Ratnatunga, Kavan U.; Casertano, Stefano

    1991-01-01

    A new numerical algorithm is used to calibrate the absolute magnitude of spectroscopically selected stars from their observed trigonometric parallax. This procedure, based on maximum-likelihood estimation, can retrieve unbiased estimates of the intrinsic absolute magnitude and its dispersion even from incomplete samples suffering from selection biases in apparent magnitude and color. It can also make full use of low accuracy and negative parallaxes and incorporate censorship on reported parallax values. Accurate error estimates are derived for each of the fitted parameters. The algorithm allows an a posteriori check of whether the fitted model gives a good representation of the observations. The procedure is described in general and applied to both real and simulated data.

  16. Recovery of absolute threshold with UVA-induced retinal damage

    SciTech Connect

    Henton, W.W.; Sykes, S.M.

    1984-06-01

    A within-trial psychophysical procedure tracked the initial loss and subsequent recovery of visual thresholds in albino rats exposed to ultraviolet light at 350 nanometers and 0.4 milliwatts per square centimeter. Absolute thresholds increased up to 5 log units immediately following the 15 hour ultraviolet exposure, with a daily recovery of 1-2 log to asymptotic thresholds over a 7-day post-exposure period. The corresponding retinal damage on Day 1 included extensive vesiculation of the photoreceptor outer segments, vacuolation of the inner segments, and pyknosis of cell nuclei. The total number of photoreceptor nuclei and outer segments was unchanged relative to control eyes through post-exposure Day 3. Both nuclei and outer segment counts then consistently decreased 15-20 percent between Days 3-7. The two-stage loss of photoreceptors but daily recovery of absolute thresholds again suggests a significant dissociation of retinal structure and psychophysical function in light-induced ocular pathology.

  17. Vocational Education at a Distance

    ERIC Educational Resources Information Center

    Dodds, Tony

    1973-01-01

    As a case study of the potential of teaching from a distance for technical and vocational training, the author has described the new, experimental Mauritius College of the Air, located on an island in the Indian Ocean, which promotes education through radio and television broadcasts, correspondence, and occasional face-to-face tuition. (EA)

  18. International Cooperation in Distance Education.

    ERIC Educational Resources Information Center

    John, Magnus

    This paper addresses some of the general issues of international cooperation within the context of distance education. Examples of the types of international cooperation are introduced in order to explain some of the pitfalls that can occur when coordinating organizations on an international level. Extensive discussion is undertaken concerning…

  19. A Distance Learning Case Study.

    ERIC Educational Resources Information Center

    Boord, Patricia M.

    1998-01-01

    To address diminishing resources and increased training demands, the Operational Training Unit (OTU) of the Federal Bureau of Investigation has saved almost $2 million by developing a distance education course to replace one full week of training at the FBI Academy. Discussion focuses on major issues faced by OTU in designing/delivering this…

  20. Distance Learning: Untried and Untrue

    ERIC Educational Resources Information Center

    Halfond, Jay A.

    2010-01-01

    G. K. Chesterton famously once said: "Christianity has not been tried and found wanting; it has been found difficult and not tried." This, the author believes, applies to distance learning as well. There is far too much self-congratulatory hyperbole about the growth and pervasiveness of online learning--which exaggerates reality and overlooks the…

  1. Distance Learners: Welcome to Campus!

    ERIC Educational Resources Information Center

    Schwitzer, Alan M.; Duggan, Mary H.

    2005-01-01

    Old Dominion University's distance learning program, called TELETECHNET, brings the main-campus college experience to geographically distant learners at sites across Virginia and as far away as the state of Washington, as well as to military personnel on Navy bases, carriers, and submarines. In an interesting turnabout, the Summer Institute for…

  2. Curriculum Control in Distance Education.

    ERIC Educational Resources Information Center

    Chesterton, Paul

    1985-01-01

    The nature of distance education is to shift the locus of curriculum control toward the institution and its staff and away from the students. This imposes a responsibility on the institution to examine and evaluate the values and assumptions underlying the decision-making and the implications of the patterns of control that emerge. (Author/MSE)

  3. Religious Distance Education Goes Online

    ERIC Educational Resources Information Center

    Frye, Steven B.

    2012-01-01

    Looking back on the use of distance education tools by religious groups, one word that stands out is change. The old adage "We've never done it that way before" will become less valid as religious bodies find themselves in the midst of a world inundated with online possibilities that call them to question how they interact with members and…

  4. Measuring Distances Using Digital Cameras

    ERIC Educational Resources Information Center

    Kendal, Dave

    2007-01-01

    This paper presents a generic method of calculating accurate horizontal and vertical object distances from digital images taken with any digital camera and lens combination, where the object plane is parallel to the image plane or tilted in the vertical plane. This method was developed for a project investigating the size, density and spatial…

  5. Interaction in Distance Nursing Education

    ERIC Educational Resources Information Center

    Boz Yuksekdag, Belgin

    2012-01-01

    The purpose of this study is to determine psychiatry nurses' attitudes toward the interactions in distance nursing education, and also scrunize their attitudes based on demographics and computer/Internet usage. The comparative relational scanning model is the method of this study. The research data were collected through "The Scale of Attitudes of…

  6. Long distance tracking of birds

    NASA Technical Reports Server (NTRS)

    Cochran, W. W.

    1972-01-01

    The application of radio telemetry techniques to the long distance tracking of birds is discussed. The types of equipment developed and methods for attachment to a bird are described. The operating range of the radio transmitter receiver system is examined, and methods for acquiring and analyzing the data are explained.

  7. Distance Education and Organizational Environment

    ERIC Educational Resources Information Center

    East, Jean F.; LaMendola, Walter; Alter, Catherine

    2014-01-01

    As distance education models in social work education continue to grow, this study addresses prevalence and type of models in graduate social work programs and the perceptions of deans about the future of e-learning models of curriculum delivery. The study was an exploratory sequential mixed-methods design including a national survey of 121…

  8. Lessons in Developing Distance Learning.

    ERIC Educational Resources Information Center

    Gant, Lenora Peters

    1996-01-01

    Describes the use of video teletraining (VTT) for distance learning in the Department of Defense. Topics include planning and organizing the VTT facility, staff development, site facilitators, the necessity of protocol, instructional design and development strategies, student involvement and interactivity, and evaluation and assessment. (LRW)

  9. Using Podcasts in Distance Education

    ERIC Educational Resources Information Center

    Koppelman, Herman

    2013-01-01

    This paper discusses three possible ways of applying podcasts in distance education: podcasts of recordings of virtual classes, podcasts produced for specific pedagogical aims, and podcasts produced by external organizations. Through a survey we gained insight in the (until now limited) experiences of our distant students with podcasts, and also…

  10. Distance Education Instructional Model Applications.

    ERIC Educational Resources Information Center

    Jackman, Diane H.; Swan, Michael K.

    1995-01-01

    A survey of graduate students involved in distance education on North Dakota State University's Interactive Video Network included 80 on campus and 13 off. The instructional models rated most effective were role playing, simulation, jurisprudential (Socratic method), memorization, synectics, and inquiry. Direct instruction was rated least…

  11. Distance Learning and Technology Plan.

    ERIC Educational Resources Information Center

    King, Maxwell C.

    Brevard Community College (BCC), in Florida, undertook a review of enrollment, social and workplace trends, and institutional capabilities to determine opportunities, barriers, and implications for the institution in implementing distance education (DE) and instructional technology. Trends analyzed included enrollment shifts toward older students,…

  12. Overcoming the Tyranny of Distance.

    ERIC Educational Resources Information Center

    Clayden, Judy

    1998-01-01

    Edith Cowan University (Perth, Western Australia) has introduced a Bachelor of Science degree in Library Technology, a three-year distance education program with no residency requirement and the first Australian degree for library technicians. This article describes the program and its use of the World Wide Web for flexible course delivery,…

  13. Distance Learning Technology and Applications.

    ERIC Educational Resources Information Center

    Minoli, Daniel

    This book is intended to give technology providers a better understanding of the dynamics of interactive distance learning (DL). For technology consumers it provides an understanding of the basics of available telecommunication technologies and the tradeoffs among available alternatives. Among the topics discussed in the book's 12 chapters are the…

  14. Diagnostic Application of Absolute Neutron Activation Analysis in Hematology

    SciTech Connect

    Zamboni, C.B.; Oliveira, L.C.; Dalaqua, L. Jr.

    2004-10-03

    The Absolute Neutron Activation Analysis (ANAA) technique was used to determine element concentrations of Cl and Na in blood of healthy group (male and female blood donators), select from Blood Banks at Sao Paulo city, to provide information which can help in diagnosis of patients. This study permitted to perform a discussion about the advantages and limitations of using this nuclear methodology in hematological examinations.

  15. Absolute Helicity Induction in Three-Dimensional Homochiral Frameworks

    PubMed Central

    Zhang, Jian; Bu, Xianhui

    2009-01-01

    Three Co(II) isomers assembled from d-, or l-, or dl-camphorate together with achiral isonicotinate exhibit a clear relationship between chirality and helicity even though chiral molecules are not in the backbone of the helix: the absolute sense of helix made of achiral components is controlled by chains of metal and enantiopure chiral ligands running perpendicular to helix in two enantiomeric forms. PMID:19099070

  16. Absolute configuration of hydroxycitric acid produced by microorganisms.

    PubMed

    Hida, Hiroyuki; Yamada, Takashi; Yamada, Yasuhiro

    2006-08-01

    Optical resolution for (2S,3R) and (2R,3S)-hydroxycitric acid (HCA) enantiomers was developed using chiral column chromatography. HCA from Bacillus megaterium G45C and Streptomyces sp. U121, newly isolated in our previous study, was analyzed to determine the absolute configuration. These results indicate that both strains generate optically pure (2S,3R)-hibiscus type HCA enantiomer. PMID:16926511

  17. On the Absolute Continuity of the Blackwell Measure

    NASA Astrophysics Data System (ADS)

    Bárány, Balázs; Kolossváry, István

    2015-04-01

    In 1957, Blackwell expressed the entropy of hidden Markov chains using a measure which can be characterised as an invariant measure for an iterated function system with place-dependent weights. This measure, called the Blackwell measure, plays a central role in understanding the entropy rate and other important characteristics of fundamental models in information theory. We show that for a suitable set of parameter values the Blackwell measure is absolutely continuous for almost every parameter in the case of binary symmetric channels.

  18. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    SciTech Connect

    Sannibale, F.; Stupakov, G.V.; Zolotorev, M.S.; Filippetto, D.; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  19. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    SciTech Connect

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  20. Successful treatment of pyogenic granuloma with injection of absolute ethanol.

    PubMed

    Ichimiya, Makoto; Yoshikawa, Yoshiaki; Hamamoto, Yoshiaki; Muto, Masahiko

    2004-04-01

    Pyogenic granuloma (PG) is a small, almost always solitary, sessile or pedunculated, raspberry-like vegetation of exuberant granulation tissue. Conservative treatment by techniques such as cryosurgery, laser surgery, and electrodesiccation are usually adequate, whereas excisional treatment can often result in noticeable scars. We attempted a different approach using an injection of absolute ethanol in five patients with recurrence due to inadequate cryosurgery. This therapy is less invasive than surgical excision and appears to be an alternative therapy for PG.

  1. Engine performance and the determination of absolute ceiling

    NASA Technical Reports Server (NTRS)

    Diehl, Walter S

    1924-01-01

    This report contains a brief study of the variation of engine power with temperature and pressure. The variation of propeller efficiency in standard atmosphere is obtained from the general efficiency curve which is developed in NACA report no. 168. The variation of both power available and power required are then determined and curves plotted, so that the absolute ceiling may be read directly from any known sea-level value of the ratio of power available to power required.

  2. Absolute GNSS Antenna Calibration at the National Geodetic Survey

    NASA Astrophysics Data System (ADS)

    Mader, G.; Bilich, A.; Geoghegan, C.

    2012-04-01

    Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna models and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these models into analysis software. To help meet the needs of the high-precision GNSS community, the National Geodetic Survey (NGS) now operates an absolute antenna calibration facility. Located in Corbin, Virginia, this facility uses field measurements and actual GNSS satellite signals to quantitatively determine the carrier phase advance/delay introduced by the antenna element. The NGS facility was built to serve traditional NGS constituents such as the surveying and geodesy communities, however calibration services are open and available to all GNSS users as the calibration schedule permits. All phase center patterns computed by this facility will be publicly available and disseminated in both the ANTEX and NGS formats. We describe the NGS calibration facility, and discuss the observation models and strategy currently used to generate NGS absolute calibrations. We demonstrate that NGS absolute phase center variation (PCV) patterns are consistent with published values determined by other absolute antenna calibration facilities, and outline future planned refinements to the system.

  3. Electroweak absolute, meta-, and thermal stability in neutrino mass models

    NASA Astrophysics Data System (ADS)

    Lindner, Manfred; Patel, Hiren H.; Radovčić, Branimir

    2016-04-01

    We analyze the stability of the electroweak vacuum in neutrino mass models containing right-handed neutrinos or fermionic isotriplets. In addition to considering absolute stability, we place limits on the Yukawa couplings of new fermions based on metastability and thermal stability in the early Universe. Our results reveal that the upper limits on the neutrino Yukawa couplings can change significantly when the top quark mass is allowed to vary within the experimental range of uncertainty in its determination.

  4. Absolute calibration and beam background of the Squid Polarimeter

    SciTech Connect

    Blaskiewicz, M.M.; Cameron, P.R.; Shea, T.J.

    1996-12-31

    The problem of beam background in Squid Polarimetry is not without residual benefits. The authors may deliberately generate beam background by gently kicking the beam at the spin tune frequency. This signal may be used to accomplish a simple and accurate absolute calibration of the polarimeter. The authors present details of beam background calculations and their application to polarimeter calibration, and suggest a simple proof-of-principle accelerator experiment.

  5. Absolute intensity of radiation emitted by uranium plasmas

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.; Lee, J. H.; Mcfarland, D. R.

    1975-01-01

    The absolute intensity of radiation emitted by fissioning and nonfissioning uranium plasmas in the spectral range from 350 nm to 1000 nm was measured. The plasma was produced in a plasma-focus apparatus and the plasma properties are simular to those anticipated for plasma-core nuclear reactors. The results are expected to contribute to the establishment of design criteria for the development of plasma-core reactors.

  6. On the Absolutely Continuous Spectrum of Stark Operators

    NASA Astrophysics Data System (ADS)

    Perelman, Galina

    The stability of the absolutely continuous spectrum of the one-dimensional Stark operator under perturbations of the potential is discussed. The focus is on proving this stability under minimal assumptions on smoothness of the perturbation. A general criterion is presented together with some applications. These include the case of periodic perturbations where we show that any perturbation vL1()∩H-1/2() preserves the a.c. spectrum.

  7. Auditory distance perception in humans: a review of cues, development, neuronal bases, and effects of sensory loss.

    PubMed

    Kolarik, Andrew J; Moore, Brian C J; Zahorik, Pavel; Cirstea, Silvia; Pardhan, Shahina

    2016-02-01

    Auditory distance perception plays a major role in spatial awareness, enabling location of objects and avoidance of obstacles in the environment. However, it remains under-researched relative to studies of the directional aspect of sound localization. This review focuses on the following four aspects of auditory distance perception: cue processing, development, consequences of visual and auditory loss, and neurological bases. The several auditory distance cues vary in their effective ranges in peripersonal and extrapersonal space. The primary cues are sound level, reverberation, and frequency. Nonperceptual factors, including the importance of the auditory event to the listener, also can affect perceived distance. Basic internal representations of auditory distance emerge at approximately 6 months of age in humans. Although visual information plays an important role in calibrating auditory space, sensorimotor contingencies can be used for calibration when vision is unavailable. Blind individuals often manifest supranormal abilities to judge relative distance but show a deficit in absolute distance judgments. Following hearing loss, the use of auditory level as a distance cue remains robust, while the reverberation cue becomes less effective. Previous studies have not found evidence that hearing-aid processing affects perceived auditory distance. Studies investigating the brain areas involved in processing different acoustic distance cues are described. Finally, suggestions are given for further research on auditory distance perception, including broader investigation of how background noise and multiple sound sources affect perceived auditory distance for those with sensory loss. PMID:26590050

  8. Bio-Inspired Stretchable Absolute Pressure Sensor Network.

    PubMed

    Guo, Yue; Li, Yu-Hung; Guo, Zhiqiang; Kim, Kyunglok; Chang, Fu-Kuo; Wang, Shan X

    2016-01-02

    A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4'' wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles.

  9. Bio-Inspired Stretchable Absolute Pressure Sensor Network

    PubMed Central

    Guo, Yue; Li, Yu-Hung; Guo, Zhiqiang; Kim, Kyunglok; Chang, Fu-Kuo; Wang, Shan X.

    2016-01-01

    A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4’’ wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles. PMID:26729134

  10. Overspecification of color, pattern, and size: salience, absoluteness, and consistency

    PubMed Central

    Tarenskeen, Sammie; Broersma, Mirjam; Geurts, Bart

    2015-01-01

    The rates of overspecification of color, pattern, and size are compared, to investigate how salience and absoluteness contribute to the production of overspecification. Color and pattern are absolute and salient attributes, whereas size is relative and less salient. Additionally, a tendency toward consistent responses is assessed. Using a within-participants design, we find similar rates of color and pattern overspecification, which are both higher than the rate of size overspecification. Using a between-participants design, however, we find similar rates of pattern and size overspecification, which are both lower than the rate of color overspecification. This indicates that although many speakers are more likely to include color than pattern (probably because color is more salient), they may also treat pattern like color due to a tendency toward consistency. We find no increase in size overspecification when the salience of size is increased, suggesting that speakers are more likely to include absolute than relative attributes. However, we do find an increase in size overspecification when mentioning the attributes is triggered, which again shows that speakers tend to refer in a consistent manner, and that there are circumstances in which even size overspecification is frequently produced. PMID:26594190

  11. Absolute measurements of nonlinear absorption near LIDT at 193 nm

    NASA Astrophysics Data System (ADS)

    Blaschke, Holger; Ristau, Detlev; Welsch, Eberhard; Apel, Oliver

    2001-04-01

    Previous investigations indicate that oxide coatings exhibit non-linear absorption phenomena below 200 nm. Hereby, absorption data of Al2O3 thin film coatings has been determined absolutely by laser calorimetry (LCA) at 193 nm in the low fluence regime. As an alternative, on the basis of the pulsed surface thermal lens technique (STL), photothermal measurements allow to determine the absorption relatively at fluence levels both in the subdamage fluence range far from the damage onset and close to the LIDT. By combining the two measurement techniques, the absolute determination of linear as well as multiphoton absorption can be achieved also in the vicinity of the laser damage fluences. This is of crucial interest because the initiation of damage onset can be observed immediately. Absolute absorption data of Al2O3 coatings at different laser fluences stating of some mJoule/cm2 will be presented for the wavelength 193 nm. Thus, the correlation between the increase of absorption and the onset of breakdown can be illustrated impressively. The evaluation and discussion of the experimental results are focused on the degree of non-linearity of the investigated absorption behavior of oxide single layers initiating the optical breakdown of UV oxide coatings.

  12. Bio-Inspired Stretchable Absolute Pressure Sensor Network.

    PubMed

    Guo, Yue; Li, Yu-Hung; Guo, Zhiqiang; Kim, Kyunglok; Chang, Fu-Kuo; Wang, Shan X

    2016-01-01

    A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4'' wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles. PMID:26729134

  13. Absolute surface reconstruction by slope metrology and photogrammetry

    NASA Astrophysics Data System (ADS)

    Dong, Yue

    Developing the manufacture of aspheric and freeform optical elements requires an advanced metrology method which is capable of inspecting these elements with arbitrary freeform surfaces. In this dissertation, a new surface measurement scheme is investigated for such a purpose, which is to measure the absolute surface shape of an object under test through its surface slope information obtained by photogrammetric measurement. A laser beam propagating toward the object reflects on its surface while the vectors of the incident and reflected beams are evaluated from the four spots they leave on the two parallel transparent windows in front of the object. The spots' spatial coordinates are determined by photogrammetry. With the knowledge of the incident and reflected beam vectors, the local slope information of the object surface is obtained through vector calculus and finally yields the absolute object surface profile by a reconstruction algorithm. An experimental setup is designed and the proposed measuring principle is experimentally demonstrated by measuring the absolute surface shape of a spherical mirror. The measurement uncertainty is analyzed, and efforts for improvement are made accordingly. In particular, structured windows are designed and fabricated to generate uniform scattering spots left by the transmitted laser beams. Calibration of the fringe reflection instrument, another typical surface slope measurement method, is also reported in the dissertation. Finally, a method for uncertainty analysis of a photogrammetry measurement system by optical simulation is investigated.

  14. An Absolute Measurement of Resonance-Resolved Electron Impact Excitation

    NASA Astrophysics Data System (ADS)

    Reisenfeld, Daniel Brett

    1998-11-01

    An experiment to measure electron-impact excitation (EIE) of multiply-charged ions is described. An absolute measurement has been carried out of the cross section for EIE of Si2+(3s2/ 1S/to3s3p/ 1P) from energies below threshold to 11 eV above. A beams modulation technique with inclined electron and ion beams was used. Radiation at 120.7 nm from the excited ions was detected using an absolutely calibrated optical system. The analysis of the experimental data requires a determination of the population fraction of the Si2+ (3s3p/ 3Po) metastable state in the incident ion beam, which was measured to be 0.210 ± 0.018. The data have been corrected for contributions to the signal from radiative decay following excitation from the metastable state to 3s3p1P and 3p2/ 3P, and excitation of the ground state to levels above 3s3p/ 1P. The experimental 0.56 ± 0.08 eV energy spread has allowed us to resolve complex resonance structure throughout the studied energy range. At the reported ±14% uncertainty level (90% confidence limit), the measured structure and absolute scale of the cross section are in good agreement with 12-state close-coupling R-matrix calculations.

  15. Son preference in Indian families: absolute versus relative wealth effects.

    PubMed

    Gaudin, Sylvestre

    2011-02-01

    The desire for male children is prevalent in India, where son preference has been shown to affect fertility behavior and intrahousehold allocation of resources. Economic theory predicts less gender discrimination in wealthier households, but demographers and sociologists have argued that wealth can exacerbate bias in the Indian context. I argue that these apparently conflicting theories can be reconciled and simultaneously tested if one considers that they are based on two different notions of wealth: one related to resource constraints (absolute wealth), and the other to notions of local status (relative wealth). Using cross-sectional data from the 1998-1999 and 2005-2006 National Family and Health Surveys, I construct measures of absolute and relative wealth by using principal components analysis. A series of statistical models of son preference is estimated by using multilevel methods. Results consistently show that higher absolute wealth is strongly associated with lower son preference, and the effect is 20%-40% stronger when the household's community-specific wealth score is included in the regression. Coefficients on relative wealth are positive and significant although lower in magnitude. Results are robust to using different samples, alternative groupings of households in local areas, different estimation methods, and alternative dependent variables.

  16. Absolute photoionization cross-section of the propargyl radical

    SciTech Connect

    Savee, John D.; Welz, Oliver; Taatjes, Craig A.; Osborn, David L.; Soorkia, Satchin; Selby, Talitha M.

    2012-04-07

    Using synchrotron-generated vacuum-ultraviolet radiation and multiplexed time-resolved photoionization mass spectrometry we have measured the absolute photoionization cross-section for the propargyl (C{sub 3}H{sub 3}) radical, {sigma}{sub propargyl}{sup ion}(E), relative to the known absolute cross-section of the methyl (CH{sub 3}) radical. We generated a stoichiometric 1:1 ratio of C{sub 3}H{sub 3} : CH{sub 3} from 193 nm photolysis of two different C{sub 4}H{sub 6} isomers (1-butyne and 1,3-butadiene). Photolysis of 1-butyne yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(26.1{+-}4.2) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(23.4{+-}3.2) Mb, whereas photolysis of 1,3-butadiene yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(23.6{+-}3.6) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(25.1{+-}3.5) Mb. These measurements place our relative photoionization cross-section spectrum for propargyl on an absolute scale between 8.6 and 10.5 eV. The cross-section derived from our results is approximately a factor of three larger than previous determinations.

  17. Measurement of Absolute Carbon Isotope Ratios: Mechanisms and Implications

    NASA Astrophysics Data System (ADS)

    Vogel, J. S.; Giacomo, J. A.; Dueker, S. R.

    2012-12-01

    An accelerator mass spectrometer (AMS) produced absolute isotope ratio measurements for 14C/13C as tested against >500 samples of NIST SRM-4990-C (OxII 14C standard) to an accuracy of 2.2±0.6‰ over a period of one year with measurements made to 1% counting statistics. The spectrometer is not maximized for 13C/12C, but measured ∂13C to 0.4±0.1‰ accuracy, with known methods for improvement. An AMS produces elemental anions from a sputter ion source and includes a charge-changing collision in a gas cell to isolate the rare 14C from the common isotopes and molecular isobars. Both these physical processes have been modeled to determine the parameters providing such absolute measures. Neutral resonant ionization in a cesium plasma produces mass-independent ionization, while velocity dependent charge-state distributions in gas collisions produce relative ion beam intensities that are linear in mass at specific collision energies. The mechanisms are not specific to carbon isotopes, but stand alone absolute IRMS (AIR-MS) instruments have not yet been made. Aside from the obvious applications in metrology, AIR-MS is particularly valuable in coupled separatory MS because no internal or external standards are required. Sample definition processes can be compared, even if no exact standard reference sample exists. Isotope dilution measurements do not require standards matching the dilution end-points and can be made over an extended, even extrapolated, range.

  18. Red clump stars from the LAMOST data I: identification and distance

    NASA Astrophysics Data System (ADS)

    Wan, Jun-Chen; Liu, Chao; Deng, Li-Cai; Cui, Wen-Yuan; Zhang, Yong; Hou, Yong-Hui; Yang, Ming; Wu, Yue

    2015-08-01

    We present a sample of about 120 000 red clump candidates selected from the LAMOST DR2 catalog based on the empirical distribution model in the effective temperature vs. surface gravity plane. Although, in general, red clump stars are considered as standard candles, they do not exactly stay in a narrow range of absolute magnitude, but may have a range of more than one magnitude depending on their initial mass. Consequently, conventional oversimplified distance estimations with the assumption of a fixed luminosity may lead to systematic bias related to the initial mass or age, which can potentially affect the study of the evolution of the Galaxy with red clump stars. We therefore employ an isochrone-based method to estimate the absolute magnitude of red clump stars from their observed surface gravities, effective temperatures and metallicities. We verify that the estimation removes the systematics well and provides initial mass/age estimates that are independent of distance with accuracy better than 10%.

  19. Mode-resolved frequency comb interferometry for high-accuracy long distance measurement

    NASA Astrophysics Data System (ADS)

    van den Berg, Steven. A.; van Eldik, Sjoerd; Bhattacharya, Nandini

    2015-09-01

    Optical frequency combs have developed into powerful tools for distance metrology. In this paper we demonstrate absolute long distance measurement using a single femtosecond frequency comb laser as a multi-wavelength source. By applying a high-resolution spectrometer based on a virtually imaged phased array, the frequency comb modes are resolved spectrally to the level of an individual mode. Having the frequency comb stabilized against an atomic clock, thousands of accurately known wavelengths are available for interferometry. From the spectrally resolved output of a Michelson interferometer a distance is derived. The presented measurement method combines spectral interferometry, white light interferometry and multi-wavelength interferometry in a single scheme. Comparison with a fringe counting laser interferometer shows an agreement within <10-8 for a distance of 50 m.

  20. Is power-space a continuum? Distance effect during power judgments.

    PubMed

    Jiang, Tianjiao; Zhu, Lei

    2015-12-01

    Despite the increasing evidence suggesting that power processing can activate vertical space schema, it still remains unclear whether this power-space is dichotomic or continuous. Here we tested the nature of the power-space by the distance effect, a continuous property of space cognition. In two experiments, participants were required to judge the power of one single word (Experiment 1) or compare the power of two words presented in pairs (Experiment 2). The power distance was indexed by the absolute difference of power ratings. Results demonstrated that reaction time decreased with the power distance, whereas accuracy increased with the power distance. The findings indicated that different levels of power were presented as different vertical heights, implying that there was a common mechanism underlying space and power cognition.