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  1. Developpement d'un modele analytique pour l'analyse en elasticite lineaire de champs de deformation et contrainte au sein d'un polycristal. comparaison avec la methode des elements finis =

    NASA Astrophysics Data System (ADS)

    Bretin, Remy

    L'endommagement par fatigue des materiaux est un probleme courant dans de nombreux domaines, dont celui de l'aeronautique. Afin de prevenir la rupture par fatigue des materiaux il est necessaire de determiner leur duree de vie en fatigue. Malheureusement, dues aux nombreuses heterogeneites presentes, la duree de vie en fatigue peut fortement varier entre deux pieces identiques faites dans le meme materiau ayant subi les memes traitements. Il est donc necessaire de considerer ces heterogeneites dans nos modeles afin d'avoir une meilleure estimation de la duree de vie des materiaux. Comme premiere etape vers une meilleure consideration des heterogeneites dans nos modeles, une etude en elasticite lineaire de l'influence des orientations cristallographiques sur les champs de deformations et de contraintes dans un polycristal a ete realisee a l'aide de la methode des elements finis. Des correlations ont pu etre etablies a partir des resultats obtenus, et un modele analytique en elasticite lineaire prenant en compte les distributions d'orientations cristallographiques et les effets de voisinage a pu etre developpe. Ce modele repose sur les bases des modeles d'homogeneisation classique, comme le schema auto-coherent, et reprend aussi les principes de voisinage des automates cellulaires. En prenant pour reference les resultats des analyses elements finis, le modele analytique ici developpe a montre avoir une precision deux fois plus grande que le modele auto-coherent, quel que soit le materiau etudie.

  2. Modelisation par elements finis du muscle strie

    NASA Astrophysics Data System (ADS)

    Leonard, Mathieu

    Ce present projet de recherche a permis. de creer un modele par elements finis du muscle strie humain dans le but d'etudier les mecanismes engendrant les lesions musculaires traumatiques. Ce modele constitue une plate-forme numerique capable de discerner l'influence des proprietes mecaniques des fascias et de la cellule musculaire sur le comportement dynamique du muscle lors d'une contraction excentrique, notamment le module de Young et le module de cisaillement de la couche de tissu conjonctif, l'orientation des fibres de collagene de cette membrane et le coefficient de poisson du muscle. La caracterisation experimentale in vitro de ces parametres pour des vitesses de deformation elevees a partir de muscles stries humains actifs est essentielle pour l'etude de lesions musculaires traumatiques. Le modele numerique developpe est capable de modeliser la contraction musculaire comme une transition de phase de la cellule musculaire par un changement de raideur et de volume a l'aide des lois de comportement de materiau predefinies dans le logiciel LS-DYNA (v971, Livermore Software Technology Corporation, Livermore, CA, USA). Le present projet de recherche introduit donc un phenomene physiologique qui pourrait expliquer des blessures musculaires courantes (crampes, courbatures, claquages, etc.), mais aussi des maladies ou desordres touchant le tissu conjonctif comme les collagenoses et la dystrophie musculaire. La predominance de blessures musculaires lors de contractions excentriques est egalement exposee. Le modele developpe dans ce projet de recherche met ainsi a l'avant-scene le concept de transition de phase ouvrant la porte au developpement de nouvelles technologies pour l'activation musculaire chez les personnes atteintes de paraplegie ou de muscles artificiels compacts pour l'elaboration de protheses ou d'exosquelettes. Mots-cles Muscle strie, lesion musculaire, fascia, contraction excentrique, modele par elements finis, transition de phase

  3. Methodes d'amas quantiques a temperature finie appliquees au modele de Hubbard

    NASA Astrophysics Data System (ADS)

    Plouffe, Dany

    Depuis leur decouverte dans les annees 80, les supraconducteurs a haute temperature critique ont suscite beaucoup d'interet en physique du solide. Comprendre l'origine des phases observees dans ces materiaux, telle la supraconductivite, est l'un des grands defis de la physique theorique du solide des 25 dernieres annees. L'un des mecanismes pressentis pour expliquer ces phenomenes est la forte interaction electron-electron. Le modele de Hubbard est l'un des modeles les plus simples pour tenir compte de ces interactions. Malgre la simplicite apparente de ce modele, certaines de ses caracteristiques, dont son diagramme de phase, ne sont toujours pas bien etablies, et ce malgre plusieurs avancements theoriques dans les dernieres annees. Cette etude se consacre a faire une analyse de methodes numeriques permettant de calculer diverses proprietes du modele de Hubbard en fonction de la temperature. Nous decrivons des methodes (la VCA et la CPT) qui permettent de calculer approximativement la fonction de Green a temperature finie sur un systeme infini a partir de la fonction de Green calculee sur un amas de taille finie. Pour calculer ces fonctions de Green, nous allons utiliser des methodes permettant de reduire considerablement les efforts numeriques necessaires pour les calculs des moyennes thermodynamiques, en reduisant considerablement l'espace des etats a considerer dans ces moyennes. Bien que cette etude vise d'abord a developper des methodes d'amas pour resoudre le modele de Hubbard a temperature finie de facon generale ainsi qu'a etudier les proprietes de base de ce modele, nous allons l'appliquer a des conditions qui s'approchent de supraconducteurs a haute temperature critique. Les methodes presentees dans cette etude permettent de tracer un diagramme de phase pour l'antiferromagnetisme et la supraconductivite qui presentent plusieurs similarites avec celui des supraconducteurs a haute temperature. Mots-cles : modele de Hubbard, thermodynamique

  4. Symetries et integrabilite des equations aux differences finies

    NASA Astrophysics Data System (ADS)

    Lafortune, Stephane

    2000-09-01

    La présente thèse porte sur l'étude des symétries et des propriétés d'intégrabilité des équations aux différences finies. Dans le chapitre 1, le groupe de symétrie ponctuelle d'un système couplé à deux équations différentielles aux différences est étudié. On montre que dans certains cas, la dimension du groupe peut être infinie. Les équations peuvent décrire l'interaction de deux longues chaînes moléculaires, chacune étant composée d'atomes d'un même type. Dans le chapitre 2, une classe de théories de champs avec interaction exponentielle est introduite. L'interaction dépend de deux matrices de ``couplage'' et est suffisamment générale pour inclure toutes les théories de champs de Toda existant dans la littérature. Les symétries de Lie ponctuelles sont obtenues pour les cas où l'on a un nombre fini, infini ou semi-infini de champs. Une attention spéciale est accordée à la présence de l'invariance conforme. Dans le chapitre 3, nous procédons à la classification et à l'étude d'équations linéarisables. Nous examinons tout d'abord l'équation de Gambier continue qui contient, comme réductions, toutes les équations de deuxième ordre intégrables par linéarisation. Nous introduisons par la suite la forme discrète de cette équation et obtenons les conditions d'intégrabilité à l'aide du confinement des singularités. Nous étudions aussi les différentes réductions du cas discret. De plus, nous obtenons des transformations de Schlesinger pour les équations de Gambier discrète et continue. Dans la dernière partie du chapitre, nous étudions une famille d'équations discrètes du deuxième ordre incluant des équations résolubles par linéarisation. Plusieurs cas intégrables sont obtenus. Dans le cas discret, l'étude de l'intégrabilité est faite à l'aide du confinement des singularités. Dans le chapitre 4, nous étudions un autre critère d'intégrabilité: l'entropie algébrique. Nous montrons que les r

  5. Des ballons pour demain

    NASA Astrophysics Data System (ADS)

    Régipa, R.

    A partir d'une théorie sur la détermination des formes et des contraintes globales d'un ballon de révolution, ou s'en rapprochant, une nouvelle famille de ballons a été définie. Les ballons actuels, dits de ``forme naturelle'', sont calculés en général pour une tension circonférencielle nulle. Ainsi, pour une mission donnée, la tension longitudinale et la forme de l'enveloppe sont strictement imposées. Les ballons de la nouvelle génération sont globalement cylindriques et leurs pôles sont réunis par un câble axial, chargé de transmettre une partie des efforts depuis le crochet (pôle inférieur), directement au pôle supérieur. De plus, la zone latérale cylindrique est soumise à un faible champ de tensions circonférencielles. Ainsi, deux paramètres permettent de faire évoluer la distribution des tensions et la forme de l'enveloppe: - la tension du câble de liaison entre pôles (ou la longueur de ce câble) - la tension circonférencielle moyenne désirée (ou le rayon du ballon). On peut donc calculer et réaliser: - soit des ballons de forme adaptée, comme les ballons à fond plat pour le bon fonctionnement des montgolfières infrarouge (projet MIR); - soit des ballons optimisés pour une bonne répartition des contraintes et une meilleure utilisation des matériaux d'enveloppe, pour l'ensemble des programmes stratosphériques. Il s'ensuit une économie sensible des coûts de fabrication, une fiabilité accrue du fonctionnement de ces ballons et une rendement opérationnel bien supérieur, permettant entre autres, d'envisager des vols à très haute altitude en matériaux très légers.

  6. Ostracode distribution in Late Pennsylvanian Finis Shale cyclothem

    SciTech Connect

    Boller, K.A.

    1985-02-01

    Four successive intergrading ostracode biofacies characterize the Finis Shale cyclothem (Cisco Group, Virgilian) near Jacksboro, Texas. Composition of the ostracode biofacies parallels the distinct megafaunal assemblages ascribed by Boardman et al (1983) to changing oxygen concentrations, water depths, and salinity. Black, organic-rich, noncalcareous, fissile shales occur near the base of the Finis. This lithofacies is barren of ostracodes and megafauna, and is interpreted to represent a deeper water, anoxic environment. The overlying dark-gray, phosphatic shales contain a diminutive pyritic molluscan fauna with abundant ammonoids and a low-diversity ostracode assemblage dominated by Healdia, indicating a dysaerobic environment. The overlying lithofacies is a medium-gray, clay-rich, calcareous shale. The Megafauna is dominated by a brachiopod-bryzoan assemblage, and a diverse Ampissites-Kirkbya ostracode association occurs. This fauna represents a shallow depth, aerobic environment. The Amphissites-Kirkbya biofacies is overlain by a dark-gray calcareous shale with abundant megafossils of the fusulind-bryozoan facies of Boardman et al. This interval is dominated by a Bairdia-Amphissites-Kelletina ostracode assemblage, indicating a shallower aerobic environment. The shale is interrupted by the Jacksboro Limestone Member, an algal limestone deposited at or near wave base, which is covered by a thin intertidal sandstone. The cyclothem is capped by noncalcareous, brown silty shale. It contains a low-diversity ostracode assemblage dominated by Cavellina and a megafaunal assemblage characterized by Myalina, which represents a shallow, brackish water environment.

  7. Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis.

    PubMed

    Mooney, Robert; Quinlan, Leo R; Corley, Gavin; Godfrey, Alan; Osborough, Conor; ÓLaighin, Gearóid

    2017-01-01

    The study aims were to evaluate the validity of two commercially available swimming activity monitors for quantifying temporal and kinematic swimming variables. Ten national level swimmers (5 male, 5 female; 15.3±1.3years; 164.8±12.9cm; 62.4±11.1kg; 425±66 FINA points) completed a set protocol comprising 1,500m of swimming involving all four competitive swimming strokes. Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed. Video recordings were also obtained and used as a criterion measure to evaluate performance. A significant positive correlation was found between the monitors and video for the identification of each of the four swim strokes (Garmin: X2 (3) = 31.292, p<0.05; Finis:X2 (3) = 33.004, p<0.05). No significant differences were found for swim distance measurements. Swimming laps performed in the middle of a swimming interval showed no significant difference from the criterion (Garmin: bias -0.065, 95% confidence intervals -3.828-6.920; Finis bias -0.02, 95% confidence intervals -3.095-3.142). However laps performed at the beginning and end of an interval were not as accurately timed. Additionally, a statistical difference was found for stroke count measurements in all but two occasions (p<0.05). These differences affect the accuracy of stroke rate, stroke length and average speed scores reported by the monitors, as all of these are derived from lap times and stroke counts. Both monitors were found to operate with a relatively similar performance level and appear suited for recreational use. However, issues with feature detection accuracy may be related to individual variances in stroke technique. It is reasonable to expect that this level of error would increase when the devices are used by recreational swimmers rather than elite swimmers. Further development to improve accuracy of

  8. Evaluation of the Finis Swimsense® and the Garmin Swim™ activity monitors for swimming performance and stroke kinematics analysis

    PubMed Central

    Mooney, Robert; Corley, Gavin; Godfrey, Alan; Osborough, Conor; ÓLaighin, Gearóid

    2017-01-01

    Aims The study aims were to evaluate the validity of two commercially available swimming activity monitors for quantifying temporal and kinematic swimming variables. Methods Ten national level swimmers (5 male, 5 female; 15.3±1.3years; 164.8±12.9cm; 62.4±11.1kg; 425±66 FINA points) completed a set protocol comprising 1,500m of swimming involving all four competitive swimming strokes. Swimmers wore the Finis Swimsense and the Garmin Swim activity monitors throughout. The devices automatically identified stroke type, swim distance, lap time, stroke count, stroke rate, stroke length and average speed. Video recordings were also obtained and used as a criterion measure to evaluate performance. Results A significant positive correlation was found between the monitors and video for the identification of each of the four swim strokes (Garmin: X2 (3) = 31.292, p<0.05; Finis:X2 (3) = 33.004, p<0.05). No significant differences were found for swim distance measurements. Swimming laps performed in the middle of a swimming interval showed no significant difference from the criterion (Garmin: bias -0.065, 95% confidence intervals -3.828–6.920; Finis bias -0.02, 95% confidence intervals -3.095–3.142). However laps performed at the beginning and end of an interval were not as accurately timed. Additionally, a statistical difference was found for stroke count measurements in all but two occasions (p<0.05). These differences affect the accuracy of stroke rate, stroke length and average speed scores reported by the monitors, as all of these are derived from lap times and stroke counts. Conclusions Both monitors were found to operate with a relatively similar performance level and appear suited for recreational use. However, issues with feature detection accuracy may be related to individual variances in stroke technique. It is reasonable to expect that this level of error would increase when the devices are used by recreational swimmers rather than elite swimmers. Further

  9. Effets de la taille finie du milieu non-linéaire sur le bruit quantique spatial généré par un oscillateur paramétrique optique confocal

    NASA Astrophysics Data System (ADS)

    Lopez, L.; Gatti, A.; Maitre, A.; Treps, N.; Gigan, S.; Fabre, C.

    2004-11-01

    Nous nous intéressons au comportement spatial des fluctuations quantiques à la sortie d'un oscillateur paramétrique optique dégénéré en modes transverses, sous le seuil. En vue de futures expériences, nous étudions les effets de la diffraction dans le milieu paramétrique sur le bruit quantique spatial. Nous montrons que l'on voit apparaître une aire de cohérence de taille finie pour les effets quantiques transverses.

  10. Methodologie de modelisation aerostructurelle d'une aile utilisant un logiciel de calcul aerodynamique et un logiciel de calcul par elements finis =

    NASA Astrophysics Data System (ADS)

    Communier, David

    Lors de l'etude structurelle d'une aile d'avion, il est difficile de modeliser fidelement les forces aerodynamiques subies par l'aile de l'avion. Pour faciliter l'analyse, on repartit la portance maximale theorique de l'aile sur son longeron principal ou sur ses nervures. La repartition utilisee implique que l'aile entiere sera plus resistante que necessaire et donc que la structure ne sera pas totalement optimisee. Pour pallier ce probleme, il faudrait s'assurer d'appliquer une repartition aerodynamique de la portance sur la surface complete de l'aile. On serait donc en mesure d'obtenir une repartition des charges sur l'aile beaucoup plus fiable. Pour le realiser, nous aurons besoin de coupler les resultats d'un logiciel calculant les charges aerodynamiques de l'aile avec les resultats d'un logiciel permettant sa conception et son analyse structurelle. Dans ce projet, le logiciel utilise pour calculer les coefficients de pression sur l'aile est XFLR5 et le logiciel permettant la conception et l'analyse structurelle sera CATIA V5. Le logiciel XFLR5 permet une analyse rapide d'une aile en se basant sur l'analyse de ses profils. Ce logiciel calcule les performances des profils de la meme maniere que XFOIL et permet de choisir parmi trois methodes de calcul pour obtenir les performances de l'aile : Lifting Line Theory (LLT), Vortex Lattice Method (VLM) et 3D Panels. Dans notre methodologie, nous utilisons la methode de calcul 3D Panels dont la validite a ete testee en soufflerie pour confirmer les calculs sur XFLR5. En ce qui concerne la conception et l'analyse par des elements finis de la structure, le logiciel CATIA V5 est couramment utilise dans le domaine aerospatial. CATIA V5 permet une automatisation des etapes de conception de l'aile. Ainsi, dans ce memoire, nous allons decrire la methodologie permettant l'etude aerostructurelle d'une aile d'avion.

  11. Modélisation 2D par Eléments Finis de phénomènes micro-ondes en milieu ouvert

    NASA Astrophysics Data System (ADS)

    Nicolas, L.; Connor, K. A.; Salon, S. J.; Ruth, B. G.; Libelo, L. F.

    1992-11-01

    We present in this paper the modelization of open boundaries microwave problems using Finite Element method, for the design of antennas or for the study of electromagnetic scattering: Finite Element formulation, coupling with Boundary Element Method or with Absorbing Boundary Conditions, modelization of current sources, calculation of far field. In a second part, we show the results concerning a high power microwave launcher. Nous présentons ici notre activité dans le domaine de la modélisation bidimensionnelle de problèmes de de micro-ondes en milieu ouvert, pour la conception d'antennes ou l'étude de problèmes de diffraction électromagnétique: formulation par la méthode des Eléments Finis, prise en compte de l'infini par la méthode des Equations Intégrales de Frontière ou par des conditions aux limites absorbantes, modélisation des sources de courant, calcul du champ lointain. Dans une seconde partie, nous illustrons ces différentes méthodes par la modélisation d'une antenne haute puissance.

  12. Rethinking theoretical approaches to stigma: a Framework Integrating Normative Influences on Stigma (FINIS).

    PubMed

    Pescosolido, Bernice A; Martin, Jack K; Lang, Annie; Olafsdottir, Sigrun

    2008-08-01

    A resurgence of research and policy efforts on stigma both facilitates and forces a reconsideration of the levels and types of factors that shape reactions to persons with conditions that engender prejudice and discrimination. Focusing on the case of mental illness but drawing from theories and studies of stigma across the social sciences, we propose a framework that brings together theoretical insights from micro, meso and macro level research: Framework Integrating Normative Influences on Stigma (FINIS) starts with Goffman's notion that understanding stigma requires a language of social relationships, but acknowledges that individuals do not come to social interaction devoid of affect and motivation. Further, all social interactions take place in a context in which organizations, media and larger cultures structure normative expectations which create the possibility of marking "difference". Labelling theory, social network theory, the limited capacity model of media influence, the social psychology of prejudice and discrimination, and theories of the welfare state all contribute to an understanding of the complex web of expectations shaping stigma. FINIS offers the potential to build a broad-based scientific foundation based on understanding the effects of stigma on the lives of persons with mental illness, the resources devoted to the organizations and families who care for them, and policies and programs designed to combat stigma. We end by discussing the clear implications this framework holds for stigma reduction, even in the face of conflicting results.

  13. Life-cycle assessment of an axial air compressor manufactured by the firm Fini Compressori

    NASA Astrophysics Data System (ADS)

    Neri, Paolo; Buttol, Patrizia; Cremonini, Marco; Ronchi, Alessio; Tani, Giovanni

    2001-02-01

    This study was performed jointly by ENEA (Italian National Agency for New Technologies, Energy and Environment), Bologna and Florence Universities and the firm FINI COMPRESSORI. The functional unit is an axial air compressor manufactured by FINI COMPRESSORI, lubricated, having a 25-litres air tank, provided by 1.8 kW electrical motor. The system boundaries include raw material extraction and the end of life of the compressor. All metallic materials have the recycling as waste scenario. The LCA is obtained by using the SimaPro 3.1 code and the two methods Eco-indicator 95 and Ecopoints. The results show that air tank and stator of electrical motor are the components with greater environmental damage, even if the damage is mainly due to the electrical energy consumed during use. The most important categories of damage produced by the air tank are carcinogenic substances, heavy metals and acidification due to the material and processes used for its manufacturing and the ones produced by aluminium part of stator are acidification and winter smog due to material manufacturing. To reduce the damage of air compressor we have proposed some design solutions to lower air temperature in cylinder and at collector outlet.

  14. Relationships between benthic communities and sedimentary environments in the Pennsylvanian Finis Shale near Jacksboro, Texas

    SciTech Connect

    Lobza, V.; Schieber, J. . Dept. of Geology)

    1993-02-01

    In a new complete exposure near Jacksboro, unweathered and highly fossiliferous Finis Shale overlies greenish laminated shales with mudcracks, and has a transgressive sandstone at the base. Five or more superimposed fossil assemblages can be distinguished. The basal sandstone is overlain by a thin red mudstone with calcareous concretions and abundant Myalina shells (very shallow water), followed by a thin sandy mudstone bed that contains abundant shell fragments and fusulinids. Then follows a black to dark-gray shale unit with abundant conularids, brachiopods, fossil seed pods and wood fragments (pyritic preservation). Modern analogs suggest that the latter might have been reworked from mangrove soils in the course of transgression. The next higher unit is a thin, highly fossiliferous horizon of light gray shale with phosphatic nodules and abundant evidence of erosion and reworking (disarticulated and broken brachiopod shells, epibionts on nodules). The uppermost unit is a dark gray shale with a brachiopod and bivalve dwarf fauna at the bottom, changing upwards into an assemblage where in contrast very large specimens are conspicuous in addition to rugose corals and soft bottom sponges. Faunal and sedimentological characteristics such as degree of bioturbation, population density, dwarf faunas, shell morphology (e.g. thin vs massive shells and spine development in brachiopods), and faunal assemblages reflect a complex interplay of oxygen levels, food supply, strength of bottom currents, turbidity, and substrate properties (firm vs soft). Careful examination of these characteristics allows detailed reconstruction of living conditions and depositional environments of a Pennsylvanian core shale.

  15. Étude par chromatographie gazeuse inverse, à concentration finie, des propriétés de surface d'échantillons obtenus par traitement thermique de la goethite : distribution des sites d'adsorption des alcanes

    NASA Astrophysics Data System (ADS)

    Brendlé, E.; Balard, H.; Papirer, E.

    1998-07-01

    Inverse Gas Chromatography (IGC), at finite concentration conditions, was applied for the evaluation of the surface properties of hematite samples obtained by heat treatment of goethite. From the alkane adsorption isotherms, the distribution of surface sites according to the adsorption energy is determined. It is shown that the surface of hematite undergoes significant changes when heated up to 500 circC. La chromatographie Gazeuse Inverse (CGI), à concentration finie, a été utilisée pour évaluer les propriétés de surface d'échantillons d'hématite obtenus par traitement thermique de la goethite. A partir des isothermes d'adsorption des alcanes, on détermine la courbe de distribution des sites de surface en fonction de l'énergie d'adsorption de molécules sondes. On montre que ces courbes évoluent en fonction du traitement thermique de la goethite et traduisent une importante modification de surface de l'hématite formée après un chauffage à 500 circC.

  16. VIEW POURING PLATFORM SHOWING MOLD POURING JACKETS AND WEIGHTS AND, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW POURING PLATFORM SHOWING MOLD POURING JACKETS AND WEIGHTS AND, IN THE FOREGROUND, SAND RETURN FROM THE SHAKEOUT ACTUATING A SIMPLE LEVER SYSTEM THAT ADDED FRESH WATER TO THE SAND IN PREPARATION FOR ITS REUSE. - Southern Ductile Casting Company, Centerville Foundry, 101 Airport Road, Centreville, Bibb County, AL

  17. Predicting flash and pour points

    SciTech Connect

    Riazi, M.R.; Daubert, T.E.

    1987-09-01

    Flash point is correlated with ASTM 10% temperature. Pour point is correlated with molecular weight, specific gravity and kinematic viscosity at 100/sup 0/F. The flash point method was tested over an ASTM 10% temperature range of about 400 to 900/sup 0/F. The correlation for pour points is applicable to fractions with molecular weights of 140 to 800 and viscosities of 1 to 3,500 cSt.

  18. Calcul de l'impédance d'un inducteur circulaire plat par conjonction des méthodes intégrales de frontière et éléments finis

    NASA Astrophysics Data System (ADS)

    Fouladgar, J.; Develey, G.

    1992-11-01

    The knowledge of the impedance of the whole inductor-load has a great importance for the design of the generators used in the induction heating technology. In this paper, we study the case of a plannar circular inductor fed by a voltage u of a variable frequency up to 30 kHz. To calculate the impedance, one should resolve the diffusion equation in a axisymetric configuration. Here we propose a mixed method, using the finit elements method in the volume of the inductor and load and a boundary elements method at their surfaces. La connaissance de l'impédance de l'ensemble inducteur-charge revêt une grande importance pour la conception des générateurs utilisés dans la technique du chauffage par induction. Dans cet article, nous étudions le cas d'un inducteur plat circulaire alimenté sous une tension fixe u, de fréquence variable jusqu'à 30 kHz. Le calcul de l'impédance passe par la résolution de l'équation de diffusion dans un système axisymétrique. Nous proposons ici une méthode mixte utilisant la méthode d'éléments finis dans le volume de la charge et de l'inducteur et la méthode d'intégrales de frontière à leur surface.

  19. Mode-bifurcation upon pouring water into a cup that depends on the shape of the cup

    NASA Astrophysics Data System (ADS)

    Nakata, Satoshi; Yamada, Akiko; Kitahata, Hiroyuki

    2005-05-01

    Mode-bifurcation that included hysteresis was investigated when water was poured into a cup via a water faucet. Three modes, i.e., accumulation flow (mode I), scattering flow (mode II), and open and shut oscillatory flow (mode III), could be produced by laterally changing the distance between the center of the cup and the landing point of water poured at a constant flow rate. Hysteresis in mode-bifurcation was observed when the distance was changed depending on the initial location of the water poured into the cup. Pendulum flow was also observed when water was poured into a shallow cell. The essential features of this mode-switching were reproduced by a numerical calculation as a function of the landing point of the poured water using two-variable (the size of the water hollow and the pressure on the water surface) differential equations that included the nature of reversed flow.

  20. When It Rains, It Pours

    ERIC Educational Resources Information Center

    Mills, Linda

    2012-01-01

    "It's raining, it's pouring, the old man is snoring!" "The itsy, bitsy spider crawled up the waterspout, down came the rain and washed the spider out. Out came the sun and dried up all the rain, and the itsy, bitsy spider went up the spout again." What do children's nursery rhymes have to do with the school library? The author begins by telling a…

  1. When It Rains, It Pours

    ERIC Educational Resources Information Center

    Mills, Linda

    2012-01-01

    "It's raining, it's pouring, the old man is snoring!" "The itsy, bitsy spider crawled up the waterspout, down came the rain and washed the spider out. Out came the sun and dried up all the rain, and the itsy, bitsy spider went up the spout again." What do children's nursery rhymes have to do with the school library? The author begins by telling a…

  2. 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.

  3. Distance Learning.

    ERIC Educational Resources Information Center

    Orey, Michael; Koenecke, Lynne; Snider, Richard C.; Perkins, Ross A.; Holmes, Glen A.; Lockee, Barbara B.; Moller, Leslie A.; Harvey, Douglas; Downs, Margaret; Godshalk, Veronica M.

    2003-01-01

    Contains four articles covering trends and issues on distance learning including: the experience of two learners learning via the Internet; a systematic approach to determining the scalability of a distance education program; identifying factors that affect learning community development and performance in asynchronous distance education; and…

  4. Simulation du comportement thermique en régime permanent d'un moteur asynchrone à refroidissement extérieur. Etude par éléments finis

    NASA Astrophysics Data System (ADS)

    Glises, R.; Hostache, G.; Kauffmann, J. M.

    1994-09-01

    The steady state thermal modelling of an 4kW asynchronous motor is realized. A design has been made thanks to the Flux2D finite element magnetic calculus software converted into a resolution tool of the heat equation. This last is used to simulate the heat flux in fluid and solid areas. A 3D study is effected thanks to two 2D studies. The first concerns a radial view (perpendicular to the mechanical axis) whereas the second is effected for an axial view (parallel to the mechanical axis). Thermal conductivities of the materials and thermal contact resistances of the motor are determined through two different tests creating different overheatings. The first is made with a sinewave supply and pre-determine the thermophysical parameters. The second effected with direct current supplies at the rotor and the stator is used to validate these last parameters. On réalise l'étude du comportement thermique en régime permanent d'un moteur asynchrone de 4kW. Le logiciel de calculs magnétiques par éléments finis flux2D est converti en un outil de résolution de l'équation de la chaleur. Cette dernière équation sert à simuler les transferts thermiques tant dans les domaines fluides que solides. Une pseudo-étude tridimensionnelle est réalisée par le biais de deux études bidimensionnelles : la première effectuée suivant un plan radial (plan perpendiculaire à l'axe du moteur) et la seconde suivant un plan axial (plan parallèle à l'axe). Les conductivités des matériaux et des résistances thermiques de contact composant le moteur sont déterminées à l'aide de deux types d'essais qui induisent des échauffements différents. Le premier est réalisé avec une alimentation sinusoïdale et sert à prédéterminer les paramètres thermophysiques. Le second est effectué avec des alimentations à courant continu tant au stator qu'au rotor et a pour rôle la validation de ces paramètres.

  5. Cinétique de la troponine Ic et valeurs seuils pour le diagnostic d'infarctus du myocarde après chirurgie cardiaque sous circulation extracorporelle

    PubMed Central

    Kallel, Samy; Jarraya, Anwar; Ellouze, Maged; Frikha, Imed; Karoui, Abbdelhamid

    2012-01-01

    Introduction L'objectif de ce travail était d’étudier la cinétique de la Troponine Ic (TnIc) après chirurgie cardiaque sous circulation extracorporelle (CEC) et établir des valeurs seuils de TnIc pour le diagnostic d'infarctus du myocarde (IDM) post opératoire. Il s'agissait d'une étude prospective type cohorte observationnelle. Méthodes Nous avons inclus 37 patients âgés de plus de 18 ans proposés pour chirurgie valvulaire ou pontage aorto coronarien sous CEC. Nous avons suivi la cinétique de TnIc par des dosages immunoenzymatique sur mini-vidas® avant et après la CEC, à H4 et H12 postopératoire puis tous les jours les 4 premiers jours. Le cutoff pour le diagnostic d'IDM post opératoire a été défini comme la valeur moyenne de troponine + deux déviations standards des patients indemnes de complications cardiaques. Résultats Les valeurs de TnIc en préopératoire étaient toutes inférieures au seuil de détection de la méthode de dosage (<0,01µg/l). Les valeurs de TnIc augmentent en postopératoire immédiat pour atteindre un maximum à H4 puis diminuent progressivement pour se normaliser après 4 à 5 jours. Les valeurs seuils ont été déterminées pour H0, H4,H12, H24, H48, H72, H96 et ont été respectivement 1.36, 2.58, 3.1, 3.23, 2.13, 1.53, 1.17 pour la chirurgie coronaire et 3.75, 5.39, 4.22, 3.41, 1.65, 1.3 1.19 pour la chirurgie valvulaire. Conclusion La connaissance de la cinétique de TnIc lors de chirurgie cardiaque non compliquée et la fixation de valeur seuil ou Cutoff permet aux cliniciens de distinguer entre dommage myocardique secondaire à la chirurgie et IDM. PMID:23396754

  6. [Distance Education.

    ERIC Educational Resources Information Center

    Wallace, Teri, Ed.; Weatherman, Dick, Ed.

    1995-01-01

    This newsletter theme issue on distance education serving individuals with disabilities considers historical developments, technology, staff training strategies, and staff training materials. It is noted that improving access to training for staff members can improve the quality of services for individuals with disabilities. The following articles…

  7. Calcul des paramètres électromagnétiques d'un moteur à réluctance à commutations par une méthode hybride: éléments finis. Equations intégrales de frontière

    NASA Astrophysics Data System (ADS)

    Omekanda, Avoki; Broche, Christian; Baland, René

    1992-11-01

    The switched reluctance motor (SRM) is a doubly salient electrical machine carrying simple windings in which flow unidirectional currents over appropriate rotor positions[1]. Because of its simplicity, robustness, and high efficiency[2, 3], SRM is evaluated for variable speed- and traction drives. In this paper, a quadratic two-dimensional technique founded upon Lagrange curvilinear elements and coupling finite element method (FEM)- and boundary integral equation method (BIEM) is used to calculate electromagnetic parameters in a SRM. The application of this method to two SRM prototypes provides an accurate analysis of the magnetostatic field and gives good values of the electromagnetic parameters of a SRM. Le moteur à réluctance à commutations est une machine électrique à structures saillantes au stator et au rotor et qui comporte des bobinages simples dans lesquels circulent des courants unidirectionnels pour des positions appropriées du rotor[1]. Grâce à sa simplicité, sa robustesse et son rendement élevé[2, 3], ce moteur à réluctance est apprécié dans les entraînements à vitesse variable et de traction. Dans cet article, nous présentons l'application d'une méthode quadratique bidimensionnelle qui couple des éléments finis (MEF) et la méthode des équations intégrales de frontière (MEIF) en vue du calcul des paramètres électromagnétiques d'un moteur à réluctance à commutations. L'application de cette méthode à deux prototypes fournit une analyse précise de la répartition du champ magnétique ainsi qu'une bonne prédiction des paramètres électromagnétiques de ces moteurs.

  8. Le mentorat dans le milieu de la santé: un hôpital de réadaptation lance un programme novateur pour les leaders émergents.

    PubMed

    Stuart, Michelle; Wilson, Carol

    2015-01-01

    Les médecins, la direction, le personnel et les bénévoles des entreprises veulent former de futurs leaders au sein de leur organisation. Le présent article décrit les efforts pour concevoir, mettre en œuvre et évaluer un programme de mentorat d'un an utilisé pour la première fois par le Glenrose Rehabilitation Hospital des Alberta Health Services. Des sondages d'évaluation ont été analysés pour faire ressortir les facteurs de succès décisifs, qui intégraient un vaste processus de candidatures diversifié de mentorés et de mentors, des critères bien définis de sélection ou de jumelage de mentorés et de mentors et un programme visant à soutenir l'acquisition du savoir par des projets, des séances d'apprentissage et des présentations.

  9. Estimating emissions from grout pouring operations

    SciTech Connect

    Ballinger, M.Y.; Hendrickson, D.W.

    1993-08-01

    Grouting is a method for disposal of low-level radioactive waste in which a contaminated solution is mixed into a slurry, poured into a large storage vault, then dried, fixing the contaminants within a stable solid matrix. A model (RELEASE) has been developed to estimate the quantity of aeorsol created during the pouring process. Information and equations derived from spill experiments were used in the model to determine release fractions. This paper discusses the derivation of the release fraction equation used in the code and the model used to account for gravity settling of particles in the vault. The input and results for a base case application are shown.

  10. AERIAL OF SHUTTLE LANDING FACILITY [SLF] POURING OF CONCRETE

    NASA Technical Reports Server (NTRS)

    1975-01-01

    AERIAL OF SHUTTLE LANDING FACILITY [SLF] POURING OF CONCRETE KSC-375C-10036.31 108-KSC-375C-10036.31, P-21426, ARCHIVE-04502 Aerial oblique of Shuttle runway facilities. Pouring concrete on runway. Direction north - altitude 100'.

  11. INTERIOR VIEW, LOOKING WEST, WITH CRANE OPERATOR, TED SEALS, POURING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, LOOKING WEST, WITH CRANE OPERATOR, TED SEALS, POURING MOLTEN METAL INTO A 1,300 TON ELECTRIC HOLDING FURNACE OR MIXER. AN ELECTRONIC SCALE RECORDED THAT 50.5 TONS OF METAL WERE POURED INTO THE FURNACE DURING THIS POUR. - American Cast Iron Pipe Company, Mixer Building, 1501 Thirty-first Avenue North, Birmingham, Jefferson County, AL

  12. A Statistical Treatment of Bioassay Pour Fractions

    NASA Technical Reports Server (NTRS)

    Barengoltz, Jack; Hughes, David W.

    2014-01-01

    The binomial probability distribution is used to treat the statistics of a microbiological sample that is split into two parts, with only one part evaluated for spore count. One wishes to estimate the total number of spores in the sample based on the counts obtained from the part that is evaluated (pour fraction). Formally, the binomial distribution is recharacterized as a function of the observed counts (successes), with the total number (trials) an unknown. The pour fraction is the probability of success per spore (trial). This distribution must be renormalized in terms of the total number. Finally, the new renormalized distribution is integrated and mathematically inverted to yield the maximum estimate of the total number as a function of a desired level of confidence ( P(pour fraction. The extension to recovery efficiency corrections is also presented. Now the product of recovery efficiency and pour fraction may be small enough that the likely value may be much larger than the usual calculation: the number of spores divided by that product. The use of this analysis would not be limited to microbiological data.

  13. A comparative evaluation of tray spacer thickness and repeat pour on the accuracy of monophasic polyvinyl siloxane impression material: in vitro study.

    PubMed

    Kumar, Sandeep; Yadav, Deepti; Yadav, Reena; Arora, Aman

    2014-01-01

    This study was aimed to determine the effect of various tray spacer thickness and subsequent repeated pours on the accuracy and dimensional stability of the impression made from monophasic polyvinyl siloxane material. Custom trays with different spacer thickness (2, 4 and 6 mm) were used for making an impression of a master model simulating 3 unit fixed partial denture with monophasic polyvinyl siloxane material. These impressions were poured with die stone and repoured. Distance between the reference points were measured and subjected to statistical analysis. Casts obtained from 1 st , 2 nd and 3 rd pour of the impression in 2, 4 and 6 mm spacer thickness tray have similar dimensional accuracy amongst each other and with the master model except in molar diameter and inter-abutment distances of cast obtained from 6 mm spacer thickness tray. The vertical distance of stone dies were decreased, whereas horizontal distance increased as the thickness of impression material is increased. There were statistically non-significant changes occurring among the repeated pours in 2, 4 and 6 mm spacer thickness. 2 and 4 mm spacer thickness are acceptable for making an impression for three unit fixed partial denture with monophasic polyvinyl siloxane material and it was not affected by two subsequent (1 st and 2 nd) repeated pours.

  14. First come, first served. Does pouring sequence matter for consumption?

    PubMed

    Stroebele-Benschop, Nanette; Dieze, Anastasia; Hilzendegen, Carolin

    2016-10-01

    Various environmental factors associated with eating and drinking affect people's food choice and food intake. Lately, the role of tableware has been studied in more detail. The aim of this study was to determine whether pouring sequence of food components affects portion size. Study 1 invited participants to pour a beverage containing both apple juice and sparkling water. Pouring apple juice first increased juice by almost 25% compared to pouring water first. Pouring water first increased water by almost 19% compared to pouring juice first confirming our hypothesis that pouring sequence affects the ratio poured. Study 2 asked participants to prepare themselves a snack containing cereals with milk. Within-subject comparisons revealed that pouring milk before cereals significantly increased both milk and cereal amounts resulting in larger overall portion size compared to pouring cereals before adding milk. Habitual tendencies for preparing foods causing a perception bias or a perception bias itself could be possible explanations for the divergent study findings. These findings show for the first time the influence of pouring and preparation sequence on portion size. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Lubricating oil containing VII pour depressant

    SciTech Connect

    Hart, W.P.; Mays, D.L.

    1986-08-19

    Lubricating oils for internal combustion engines typically contain a multitude of additives which function as detergents, dispersants, viscosity index improvers, pour depressants, etc. in order to improve the properties of the oil. It is found that it is particularly necessary to improve the properties exhibited by lubricating oil compositions at low temperatures. It is an object of this invention to provide a lubricating oil containing an additive which provides improved properties at low temperatures.

  16. 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…

  17. FRONT VIEW OF POURING FROM #61 HOLDING FURNACE AT #02 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FRONT VIEW OF POURING FROM #61 HOLDING FURNACE AT #02 STATION INTO THREE VERTICAL MOLDS SUBMERGED IN A WATER-FILLED TANK BELOW THE CASTING FLOOR. THE CASTING CREW'S JOBS DURING THIS PHASE OF THE OPERATION INCLUDE REGULATING THE POURING RATE AND MONITORING THE VALVE RODS THAT CONTROL THE WATER SPRAYS ON THE MOLDS. DIFFERENT ALLOYS REQUIRE SPECIFIC POURING SPEEDS AND WATER PRESSURES. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  18. Fabrication de transistors monoelectroniques pour la detection de charge

    NASA Astrophysics Data System (ADS)

    Richard, Jean-Philippe

    Le transistor monoelectro'nique (SET) est un candidat que l'on croyait avoir la capacite de remplacer le transistor des circuits integres actuel (MOSFET). Pour des raisons de faible gain en voltage, d'impedance de sortie elevee et de sensibilite aux fluctuations de charges, il est considere aujourd'hui qu'un hybride tirant profit des deux technologies est plus avantageux. En exploitant sa lacune d'etre sensible aux variations de charge, le SET est davantage utilise dans des applications ou la detection de charge s'avere indispensable, notamment dans les domaines de la bio-detection et de l'informatique quantique. Ce memoire presente une etude du transistor monoelectronique utilise en tant que detecteur de charge. La methode de fabrication est basee sur le procede nanodamascene developpe par Dubuc et al. [11] permettant au transistor monoelectronique de fonctionner a temperature ambiante. La temperature d'operation etant intimement liee a la geometrie du SET, la cle du procede nanodamascene reside dans le polissage chimico-mecanique (CMP) permettant de reduire l'epaisseur des SET jusqu'a des valeurs de quelques nanametres. Dans ce projet de maitrise, nous avons cependant opte pour que le SET soit opere a temperature cryogenique. Une faible temperature d'operation permet le relachement des contraintes de dimensions des dispositifs. En considerant les variations de procedes normales pouvant survenir lors de la fabrication, la temperature d'operation maximale calculee en conception s'etend de 27 K a 90 K, soit une energie de charge de 78 meV a 23 meV. Le gain du detecteur de charge etant dependant de la distance de couplage, les resultats de simulations demontrent que cette distance doit etre de 200 nm pour que la detection de charge soit optimale. Les designs concus sont ensuite fabriques sur substrat d'oxyde de silicium. Les resultats de fabrication de SET temoignent de la robustesse du procede nanodamascene. En effet, les dimensions atteintes experimentalement s

  19. Suitable Learning Styles for Intelligent Tutoring Technologies (Styles d’Apprentissage Appropries pour les Technologies Tuteurs Intelligents)

    DTIC Science & Technology

    2010-05-01

    des tuteurs intelligents. Pour rendre la technologie efficace dans un environnement de formation à distance, les styles d’apprentissage de chaque...psychometric test itself found that the internal consistency and factorial validity of the categories, properties and boundaries of the modeled...circumstances where reliability has not been confirmed ( internally or by independent reviewers), a discussion on its constructs and factors’ validity is

  20. Traitement des conditions aux limites intérieures et extérieures pour la simulation numérique unidimensionnelle de l'écoulement de l'eau dans les canaux à surface libre

    NASA Astrophysics Data System (ADS)

    Abdallah, M.; Vazquez, J.; Mose, R.; Zoaeter, M.

    2005-05-01

    Dans ce papier, on décrit le traitement des conditions aux limites intérieures et extérieures couplé avec la méthode explicite aux différences finies de Roe pour le développement d'une modélisation unidimensionnelle qui sert à résoudre les équations de Saint-Venant décrivant l'écoulement de l'eau à surface libre. Les deux méthodes les plus utilisées pour trouver la solution aux nœuds intérieurs et extérieurs définissant les conditions aux limites intérieures et extérieures d'un schéma numérique sont décrites et comparées dans deux exemples: Le premier traite le problème du ressaut hydraulique et le second décrit l'écoulement de l'eau au dessus des seuils. Deux types de discrétisation du terme source, pointwise et upwind, sont considérés et comparés aussi. Les résultats obtenus et comparés avec la solution analytique dans le cas du ressaut, et avec les résultats numériques déjà publiés dans le cas des seuils, montrent l'avantage de la méthode des caractéristiques sur la méthode de l'extrapolation pour les conditions aux limites, et la discrétisation upwind du terme source sur la discrétisation pointwise.

  1. A statistical treatment of bioassay pour fractions

    NASA Astrophysics Data System (ADS)

    Barengoltz, Jack; Hughes, David

    A bioassay is a method for estimating the number of bacterial spores on a spacecraft surface for the purpose of demonstrating compliance with planetary protection (PP) requirements (Ref. 1). The details of the process may be seen in the appropriate PP document (e.g., for NASA, Ref. 2). In general, the surface is mechanically sampled with a damp sterile swab or wipe. The completion of the process is colony formation in a growth medium in a plate (Petri dish); the colonies are counted. Consider a set of samples from randomly selected, known areas of one spacecraft surface, for simplicity. One may calculate the mean and standard deviation of the bioburden density, which is the ratio of counts to area sampled. The standard deviation represents an estimate of the variation from place to place of the true bioburden density commingled with the precision of the individual sample counts. The accuracy of individual sample results depends on the equipment used, the collection method, and the culturing method. One aspect that greatly influences the result is the pour fraction, which is the quantity of fluid added to the plates divided by the total fluid used in extracting spores from the sampling equipment. In an analysis of a single sample’s counts due to the pour fraction, one seeks to answer the question: What is the probability that if a certain number of spores are counted with a known pour fraction, that there are an additional number of spores in the part of the rinse not poured. This is given for specific values by the binomial distribution density, where detection (of culturable spores) is success and the probability of success is the pour fraction. A special summation over the binomial distribution, equivalent to adding for all possible values of the true total number of spores, is performed. This distribution when normalized will almost yield the desired quantity. It is the probability that the additional number of spores does not exceed a certain value. Of course

  2. Distance Education Council.

    ERIC Educational Resources Information Center

    Indira Gandhi National Open University, New Delhi (India). Distance Education Council.

    Since its inception in India in 1962, distance education has grown in popularity. The Distance Education Council (DEC) directs distance learning within India's higher education system. The DEC's promotion, coordination, and maintenance of standards for distance education are its three major roles. Its initiatives include grants, support for…

  3. 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…

  4. Distance Education in Turkey

    ERIC Educational Resources Information Center

    Ruzgar, Nursel Selver

    2004-01-01

    Many countries of the world are using distance education with various ways, by INTERNET, by post and by TV. In this work, development of distance education in Turkey has been presented from the beginning. After discussing types and applications for different levels of distance education in Turkey, the distance education was given in the cultural…

  5. 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…

  6. AERIAL OF SHUTTLE LANDING FACILITY [SLF] POURING CONCRETE ON RUNWAY

    NASA Technical Reports Server (NTRS)

    1975-01-01

    AERIAL OF SHUTTLE LANDING FACILITY [SLF] POURING CONCRETE ON RUNWAY KSC-375C-10036.32 108-KSC-375C-10036.32, P-21425, ARCHIVE-04501 Aerial oblique of Shuttle Landing Facility. Pouring concrete on runway. Direction North - Altitude 100'.

  7. 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)

  8. 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)

  9. Modelisation numerique de l'hydrologie pour l'aide a la gestion des bassins versants, par l'utilisation conjointe des systemes d'information geographique et de la methode des elements finis un nouvel outil pour le developpement durable SAGESS

    NASA Astrophysics Data System (ADS)

    Bel Hadj Kacem, Mohamed Salah

    All hydrological processes are affected by the spatial variability of the physical parameters of the watershed, and also by human intervention on the landscape. The water outflow from a watershed strictly depends on the spatial and temporal variabilities of the physical parameters of the watershed. It is now apparent that the integration of mathematical models into GIS's can benefit both GIS and three-dimension environmental models: a true modeling capability can help the modeling community bridge the gap between planners, scientists, decision-makers and end-users. The main goal of this research is to design a practical tool to simulate run-off water surface using Geographic design a practical tool to simulate run-off water surface using Geographic Information Systems and the simulation of the hydrological behavior by the Finite Element Method.

  10. APPARATUS FOR MELTING AND POURING METAL

    DOEpatents

    Harris, F.A.

    1958-02-25

    This patent relates to a crucible for melting and pouring a metal under controlled atmospheric conditions. The crucible has a frangible plug in the bottom and a retaining device to prevent the entrance of the broken portions of the plug into the mold without interfering with the flow of the melt. After the charge has been melted, a knockout rod is lowered through the charge and forced against the frangible plug sufficiently to break off the closure disk along a previously scored line. The disk drops onto a retaining grid large enough to permit the flow of metal around the disk and into the mold below. Thts arrangement elimnates the entry of broken portions of the plug into the mold, thereby elimnating a common cause of imperfect castings.

  11. Going the Distance.

    ERIC Educational Resources Information Center

    Leno, Arthur J.

    2003-01-01

    Describes the development and implementation of the distance education program at Peirce College. This Internet-mediated distance learning program focuses on practical fields of study, drawing on the college's strengths in business administration, information technology, and paralegal studies. (SLD)

  12. Expanding Ring for the DWPF Melter Pour Spout

    SciTech Connect

    Imrich, K.J.

    2002-09-23

    The Materials Technology Section was requested to develop a novel concept, namely that of an expanding ring, to restore the upper knife edge in the DWPF melter pour spout. The expanding ring is a unit that, when deployed in the DPWF pour spout, will self-expand against the inner diameter of the 3-inch section of the pour spout providing a seal against glass leakage and a new knife edge that will mate with a Type 3A insert. This report provides a summary of the final design features of the expanding ring and an overview of its development.

  13. Theme: Distance Education.

    ERIC Educational Resources Information Center

    Whittington, M. Susie, Ed.; And Others

    1994-01-01

    Includes "Next Best Thing to Being There" (Whittington); "Taking the Distance out of Distance Education" (Miller, King); "Preparing a Course for Distance Delivery" (Newcomb); "Team Teaching via Two-Way Interactive Video" (Nichols, Trout); "Using the Ag Ed Network" (Peal); "Student's Perspective" (Schoellhorn); "Need for Instruction in Agriculture…

  14. 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…

  15. 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;…

  16. The concrete technology of post pouring zone of raft foundation of Hongyun Building B tower

    NASA Astrophysics Data System (ADS)

    Yin, Suhua; Yu, Liu; Wu, Yanli; Zhao, Ying

    2017-08-01

    The foundation of Hongyun building B tower is made of raft board foundation which is 3300mm in the thickness concreted pouring amount of large and the late poured band in the pouring settlement formed. The temperature of the pouring settlement was controlled in order to prevent the crack of the construction of the late poured band. The steel of post pouring band was designed and monitorred. The quality of post pouring band quality is guaranteed in the raft concrete foundation of Hongyun Building B tower.

  17. Transfert radiatif numerique pour un code SPH

    NASA Astrophysics Data System (ADS)

    Viau, Joseph Edmour Serge

    2001-03-01

    Le besoin de reproduire la formation d'etoiles par simulations numeriques s'est fait de plus en plus present au cours des 30 dernieres annees. Depuis Larson (1968), les codes de simulations n'ont eu de cesse de s'ameliorer. D'ailleurs, en 1977, Lucy introduit une autre methode de calcul venant concurrencer la methode par grille. Cette nouvelle facon de calculer utilise en effet des points a defaut d'utiliser des grilles, ce qui est une bien meilleure adaptation aux calculs d'un effondrement gravitationnel. Il restait cependant le probleme d'ajouter le transfert radiatif a un tel code. Malgre la proposition de Brookshaw (1984), qui nous montre une formule permettant d'ajouter le transfert radiatif sous la forme SPH tout en evitant la double sommation genante qu'elle implique, aucun code SPH a ce jour ne contient un transfert radiatif satisfaisant. Cette these presente pour la premiere fois un code SPH muni d'un transfert radiatif adequat. Toutes les difficultes ont pu etre surmontees afin d'obtenir finalement le transfert radiatif "vrai" qui survient dans l'effondrement d'un nuage moleculaire. Pour verifier l'integrite de nos resultats, une comparaison avec le nonisothermal test case de Boss & Myhill (1993) nous revele un resultat fort satisfaisant. En plus de suivre fidelement la courbe de l'evolution de la temperature centrale en fonction de la densite centrale, notre code est exempt de toutes les anomalies rencontrees par les codes par grille. Le test du cas de la conduction thermique nous a lui aussi servit a verifier la fiabilite de notre code. La aussi les resultats sont fort satisfaisants. Faisant suite a ces resultats, le code fut utilise dans deux situations reelles de recherche, ce qui nous a permis de demontrer les nombreuses possibilites que nous donne notre nouveau code. Dans un premier temps, nous avons tudie le comportement de la temperature dans un disque d'accretion durant son evolution. Ensuite nous avons refait en partie une experience de Bonnell

  18. Decodeurs rapides pour codes topologiques quantiques

    NASA Astrophysics Data System (ADS)

    Duclos-Cianci, Guillaume

    L'encodage topologique de l'information quantique a attire beaucoup d'attention, car c'est un modele qui semble propice a resister aux erreurs locales. Tout d'abord, le modele du calcul topologique est base sur la statistique anyonique non-Abelienne universelle et sur son controle. Des anyons indesirables peuvent apparaitre soudainement, en raison de fluctuations thermiques ou de processus virtuels. La presence de ces anyons peut corrompre l'information encodee, il est necessaire de les eliminer: la correction consiste a fusionner les defauts tout en preservant la topologie du systeme. Ensuite, dans le cas des codes topologiques, on doit aussi proteger l'information encodee dans la topologie. En effet, dans ces systemes, on n'a acces qu'a une fraction de l'information decrivant l'erreur. Elle est recueillie par des mesures et peut etre interpretee en termes de particules. Ces defauts peuplent le code et doivent etre annihiles adequatement dans le but de preserver l'information encodee. Dans ce memoire, nous proposons un algorithme efficace, appele decodeur, pouvant etre utilise dans les deux contextes decrits ci-haut. Pour y parvenir, cet algorithme s'inspire de methodes de renormalisation et de propagation de croyance. Il est exponentiellement plus rapide que les methodes deja existantes, etant de complexite O (ℓ2 log ℓ) en serie et, si on parallelise, O (log ℓ) en temps, contre O (ℓ6) pour les autres decodeurs. Le temps etant le facteur limitant dans le probleme du decodage, cette caracteristique est primordiale. De plus, il tolere une plus grande amplitude de bruit que les methodes existantes; il possede un seuil de ˜ 16.5% sur le canal depolarisant surpassant le seuil deja etabli de ˜ 15.5%. Finalement, il est plus versatile. En effet, en etant limite au code de Kitaev, on ne savait pas decoder les codes topologiques de maniere generale (e.g. codes de couleur). Or, le decodeur propose dans ce memoire peut traiter la grande classe des codes

  19. POURING IRON FROM ELECTRIC FURNACE INTO BULL LADLE AFTER MAGNESIUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    POURING IRON FROM ELECTRIC FURNACE INTO BULL LADLE AFTER MAGNESIUM HAD BEEN ADDED TO GENERATE DUCTILE IRON WHEN IT COOLS IN THE MOLD. - Southern Ductile Casting Company, Casting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  20. 41. Casting floor, "B" furnace, pour in progress; mudgun is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Casting floor, "B" furnace, pour in progress; mudgun is to right of furnace; photo taken from furnace operator's booth. Looking south/southwest - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

  1. 6. VIEW LOOKING WEST FROM THE POURING AISLE OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW LOOKING WEST FROM THE POURING AISLE OF THE ELECTRIC FURNACE BUILDING AT ELECTRIC FURNACE X-3. - U.S. Steel Duquesne Works, Electric Furnace Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  2. Interior building details of Building A, dungeon northwest cell: poured ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon northwest cell: poured concrete floors, plastered finished walls, exposed brick wall, vaulted veiling; westerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  3. Interior building details of Building A, dungeon central hallway: poured ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon central hallway: poured concrete floors, plaster-finished brick walls, vaulted ceiling, arch entryway to cells; southerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  4. 47. Pouring deck columns, steampowered concrete mixer at center; direction ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Pouring deck columns, steam-powered concrete mixer at center; direction of view not clear, but probably to north. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  5. 45. EXPOSEDAGGREGATE CONCRETE AT NICHE, NORTH BOUNDARY, SEVERAL TEXTURES POURED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. EXPOSED-AGGREGATE CONCRETE AT NICHE, NORTH BOUNDARY, SEVERAL TEXTURES POURED AT ONE TIME, October 1987 - Meridian Hill Park, Bounded by Fifteenth, Sixteenth, Euclid & W Streets, Northwest, Washington, District of Columbia, DC

  6. POURING IRON FROM BULL LADLE INTO MOBILE LADLES USED TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    POURING IRON FROM BULL LADLE INTO MOBILE LADLES USED TO FILL MOLDS ON CONVEYOR LINES AFTER FERRO-SILICON IS ADDED TO ENHANCE DUCTILITY AND FLUIDITY. - Southern Ductile Casting Company, Casting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  7. 42. Casting floor, "B" furnace, pour in progress; mudgun is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Casting floor, "B" furnace, pour in progress; mudgun is to right of furnace; operator takes temperature of iron in trough during pout. Looking south - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

  8. 13. MASS OF POURED CONCRETE IN IRREGULAR STEPPED LAYERS AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. MASS OF POURED CONCRETE IN IRREGULAR STEPPED LAYERS AT THE BASE OF THE LEFT (EAST) BUTTRESS. CAMERA FACING SOUTHWEST. - Salinas Dam, Salinas River near Pozo Road, Santa Margarita, San Luis Obispo County, CA

  9. 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.

  10. 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…

  11. Distance Perception within Europe.

    ERIC Educational Resources Information Center

    Eysberg, Cees D.

    1985-01-01

    A distance perception survey was used to get college students enrolled in a human geography course involved and interested in the topic of perception. Students were asked to arrange 12 European capitals in sequence according to their distance from Amsterdam. Survey results are presented. (RM)

  12. A Distance Education Exemption?

    ERIC Educational Resources Information Center

    Salomon, Kenneth D.

    1999-01-01

    Discusses the U.S. Copyright Office's May 25, 1999 Report on Copyright and Digital Distance Education. Presents the Register of Copyrights' recommendations to Congress as to how to "promote distance education through networks, while maintaining an appropriate balance between the rights of copyright owners and the needs of users of copyrighted…

  13. Distance Education in Entwicklungslandern.

    ERIC Educational Resources Information Center

    German Foundation for International Development, Bonn (West Germany).

    Seminar and conference reports and working papers on distance education of adults, which reflect the experiences of many countries, are presented. Contents include the draft report of the 1979 International Seminar on Distance Education held in Addis Ababa, Ethiopia, which was jointly sponsored by the United Nations Economic Commission for Africa…

  14. Distance, Education and Inequality

    ERIC Educational Resources Information Center

    Hamnett, Chris; Butler, Tim

    2013-01-01

    In this paper we examine the role which distance, in a variety of forms, can play in the reproduction, intensification or reduction of educational inequality in different types of school systems in different countries. This is a very broad issue, and in the paper we examine the ways in which distance to school has emerged as an important factor in…

  15. 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…

  16. "Distance Education for Newbies".

    ERIC Educational Resources Information Center

    Lennex, Lesia C.

    This paper discusses the effectiveness of distance education at Morehead State University. Distance education, which operates via fiber optic telecommunications, has been delivered to as many as 18 sites. Twenty-three faculty and 622 students have participated in this program. The technologies used to present information include full motion video…

  17. Gender and Distance Learning.

    ERIC Educational Resources Information Center

    Brunner, Cornelia

    This article examines distance learning from a gender perspective. In any new area of enterprise, expectations have an important effect on planning, implementation, and evaluation. When it comes to distance learning, a variety of images of what this exciting new technology will look like and what it can empower us to achieve will determine how we…

  18. 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,"…

  19. Technology and Distance Education.

    ERIC Educational Resources Information Center

    Lumsden, Bruce; And Others

    The impact of the computer on education may be greater than the impact of any other technological innovation since the development of the printing press. Although distance education has relied more extensively on technological means for delivering education to its students than has traditional classroom-centered education, most distance programs…

  20. Distance Education in Entwicklungslandern.

    ERIC Educational Resources Information Center

    German Foundation for International Development, Bonn (West Germany).

    Seminar and conference reports and working papers on distance education of adults, which reflect the experiences of many countries, are presented. Contents include the draft report of the 1979 International Seminar on Distance Education held in Addis Ababa, Ethiopia, which was jointly sponsored by the United Nations Economic Commission for Africa…

  1. Estimating distances from parallaxes

    NASA Astrophysics Data System (ADS)

    Astraatmadja, Tri L.; Bailer-Jones, Coryn

    2017-01-01

    In astrometric surveys such as Gaia and LSST, parallaxes will be measured for about a billion stars, but zero distances will be measured. Distances must be inferred from the parallaxes, and the common inference practice is by inverting the parallax. This, however, is only appropriate when there is no noise present. As noise will always be present and most stars in future surveys will have non-negligible fractional parallax uncertainties, we must treat distance estimation as an inference problem. The usage of prior assumptions become unavoidable. In this talk I will present a method on how to infer distances using Bayesian inference. Three minimalists, isotropic priors are used, as well an anisotropic prior derived from the observability of stars in a Milky Way model. The performance of these priors are investigated using a simulated Gaia-like catalogue. Recent results of distance estimation using the parallaxes of 2 million Gaia DR1 stars will also be discussed.

  2. Developpement et validation d'un outil base sur l'acoustique geometrique pour le diagnostic du bruit de nacelle

    NASA Astrophysics Data System (ADS)

    Minard, Benoit

    plusieurs points de l'espace à partir de rayons convergents (sommation des contributions de chaque rayon) : sommation cohérente. Le code (GA3DP) permet de prendre en compte les traitements de surface des parois, la directivité de la source, l'atténuation atmosphérique et la diffraction d'ordre 1. Le code a été validé en utilisant différentes méthodes telles que la méthode des sources-images, la méthode d'analyse modale ou encore la méthode des éléments finis de frontière. Un module Matlab a été créé spécialement pour l'étude des effets d'installation et intégré au code existant chez Pratt & Whitney Canada. Mots-clés : Acoustique géométrique - Ray-Tracing - Lancer de faisceaux - Diffraction - Sommation Cohérente - Niveau de Pression.

  3. The influence of tray space and repeat pours on the accuracy of monophasic polyvinylsiloxane impression.

    PubMed

    Rajapur, Anand; Dixit, Santosh; Hoshing, Chetan; Raikar, Sonal P

    2012-11-01

    While literature demonstrates that the optimum accuracy is obtained with the custom trays, the use of stock trays for elastomeric impressions appears to be popular in general practice. The aim of the study was to evaluate the effect of thickness of impression material on the dimensional accuracy of impressions made from monophasic polyvinylsiloxane impression material. This study also studies the dimensional stability of the impressions poured at different time intervals. A metal model simulating two abutment teeth was fabricated along with reference lines inscribed on them. Custom impression trays were fabricated with spacer thickness of 2, 4 and 6 mm. impressions were made using monophasic polyvinyl siloxane impression material. The impressions were poured and stone models were obtained. The dimensional accuracy of the impressions were determined indirectly by measuring the dimensional changes of the recovered stone models. The dimensional stability was also evaluated by pouring the impressions at time intervals of 1 hour, 24 hours and 7 days. The obtained data was statistically analyzed. The results of the study indicated that the impressions made from 2 and 4 mm tray space produced more accurate stone models when compared to 6 mm tray space. There was no significant deviation in the mesiodistal and buccolingual dimensions when impressions were made using impression trays with 2, 4 and 6 mm tray spacers. There was a significant decrease in interabutment distance (p = 0.001) and height of the abutment (p = 0.024) when impressions were made using impression trays with a tray space of 6 mm. There were no significant differences found among the stone models obtained from 1 hour, 24 hours and 1 week pour times. The mesiodistal and buccolingual dimensions of the abutments were not affected by the variations in thickness of impression material. There was a decrease in the height of the abutment which was clinically not significant. As the thickness of the impression

  4. Investigation of waste glass pouring behavior over a knife edge

    SciTech Connect

    Ebadian, M.A.

    1998-01-01

    The development of vitrification technology for converting radioactive waste into a glass solid began in the early 1960s. Some problems encountered in the vitrification process are still waiting for a solution. One of them is wicking. During pouring, the glass stream flows down the wall of the pour spout until it reaches an angled cut in the wall. At this point, the stream is supposed to break cleanly away from the wall of the pour spout and fall freely into the canister. However, the glass stream is often pulled toward the wall and does not always fall into the canister, a phenomenon known as wicking. Phase 1 involves the assembly, construction, and testing of a melter capable of supplying molten glass at operational flow rates over a break-off point knife edge. Phase 2 will evaluate the effects of glass and pour spout temperatures as well as glass flow rates on the glass flow behavior over the knife edge. Phase 3 will identify the effects on wicking resulting from varying the knife edge diameter and height as well as changing the back-cut angle of the knife edge. The following tasks were completed in FY97: Design the experimental system for glass melting and pouring; Acquire and assemble the melter system; and Perform initial research work.

  5. Galactic Distance Scales

    NASA Astrophysics Data System (ADS)

    Feast, Michael W.

    This chapter begins with a discussion of the basic methods of determining astronomical distances, particularly, trigonometrical, statistical, and pulsational parallaxes. It then summarizes the current state of the calibration of various classes of pulsating variables (Classical Cepheids, type-II Cepheids, RR Lyraes, Miras, and δ Sct and SX Phe stars). Work on other distance indicators (e.g., the red giant clump and the tip of the red giant branch) is also summarized. The use of spectroscopic parallaxes and their application to supergiants and common stars as well as the methods of determining the distances to open and globular clusters are discussed. To illustrate and compare different distance indicators, their use in estimating the scale length of our Galaxy, and the distance to Galactic centre as well as the distances to the LMC, the Fornax dwarf spheroidal, and the spiral galaxy NGC4258 is discussed in some detail. An appendix summarizes some common bias problems that arise in the calibration and use of distance indicators.

  6. Ablation laser pour la microélectronique plastique

    NASA Astrophysics Data System (ADS)

    Alloncle, A.-P.; Thomas, B.; Grojo, D.; Delaporte, Ph.; Sentis, M.; Sanaur, S.; Barret, M.; Collot, Ph.

    2006-12-01

    La microélectronique plastique connaît un développement sans précédent dans le domaine de la recherche. Cette étude s'intéresse à l'utilisation des lasers impulsionnels pour la réalisation de composants organiques sur supports souples. Les deux aspects plus particulièrement étudiés sont d'une part la gravure de polymère pour réaliser un canal entre la source et le drain, et d'autre part le développement d'un procédéde dépôt appelé LIFT pour Laser Induced Forward Transfer. Ce dernier pourrait notamment permettre dedéposer des composés organiques non solubles.

  7. Transmission Sur Fibres Optiques Dans Un Systeme D'Archivage Et De Communication D'Images Pour Des Applications Medicales

    NASA Astrophysics Data System (ADS)

    Aaron, Gilles; Bonnard, Rene

    1984-03-01

    Dans l'hOpital, le besoin d'un reseau de communication electronique ne cesse de crottre au fur et a mesure de la numerisation des images. Ce reseau local a pour but de relier quelques sources d'images telles la radiologie numerique, la tomodensitometrie, la resonance magnetique nucleaire, l'echographie ultraso-nore etc..., a un systme d'archivage. Des consoles de visualisation interacti-ves peuvent etre utilisees dans les salles d'examens, les bureaux des medecins et les services de soins. Dans un tel systme, trois caracteristiques princi-pales doivent etre prises en compte le debit, la longueur du cable et le nombre de connexions. - Le debit est tr?)s important, en effet, un temps de reponse maxima de quel-ques secondes doit etre garanti pour des images de plusieurs millions d'ele-ments binaires. - La distance entre connexions peut etre de quelques km dans certains grands hopitaux. - Le nombre de connexions au reseau ne depasse jamais quelques dizaines car les sources d'images et les unites de traitement representent des materiels importants, par ailleurs les consoles de visualisation simples peuvent etre groupees en grappe. Toutes ces conditions sont remplies par les transmissions sur fibres optiques. Selon la topologie et la methode d'accNs, deux solutions peuvent etre envisa-gees : - Anneau actif - Etoile active ou passive Enfin, les developpements de Thomson-CSF en composants pour transmissions optiques pour les grands reseaux de tel4distribution nous apportent un support technologique et une production de masse qui diminuera les collts du materiel.

  8. Geodetic distance measuring apparatus

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.

    1980-12-01

    A geodetic distance measuring apparatus which compensates for the refractive index of the atmosphere is discussed. A mode locked laser system with a laser device and its peripheral components is utilized to derive two mutually phase locked optical wavelength signals and one phase locked microwave CW signal which respectively traverse the same distance measurement path. The optical signals are comprised of pulse type signals. Phase comparison of the two optical wavelength pulse signals is used to provide the dry air density while phase comparison of one of the optical wavelength pulse signals and the microwave CW signal issued to provide wet or water vapor density of the air. The distance to be measured corrected for the atmospheric dry air and water vapor densities in the measurement path is computed from these measurements. A time interval unit is included for measuring transit time of individual optical pulses for resolving the phase ambiguity needed with the phase measurements to give the true target distance.

  9. 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)

  10. Learning Pullback HMM Distances.

    PubMed

    Cuzzolin, Fabio; Sapienza, Michael

    2014-07-01

    Recent work in action recognition has exposed the limitations of methods which directly classify local features extracted from spatio-temporal video volumes. In opposition, encoding the actions' dynamics via generative dynamical models has a number of attractive features: however, using all-purpose distances for their classification does not necessarily deliver good results. We propose a general framework for learning distance functions for generative dynamical models, given a training set of labelled videos. The optimal distance function is selected among a family of pullback ones, induced by a parametrised automorphism of the space of models. We focus here on hidden Markov models and their model space, and design an appropriate automorphism there. Experimental results are presented which show how pullback learning greatly improves action recognition performances with respect to base distances.

  11. Distance to Dark Bodies

    NASA Image and Video Library

    2007-05-30

    Using the unique orbit of NASA 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.

  12. 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.

  13. Automobile Stopping Distances.

    ERIC Educational Resources Information Center

    Logue, L. J.

    1979-01-01

    Discusses the effect of vehicle mass on stopping distances. Analyzes an example of a sample vehicle and tire, and calculates the braking acceleration showing the effect of different factors on the stopping performance of the tires. (GA)

  14. Automobile Stopping Distances.

    ERIC Educational Resources Information Center

    Logue, L. J.

    1979-01-01

    Discusses the effect of vehicle mass on stopping distances. Analyzes an example of a sample vehicle and tire, and calculates the braking acceleration showing the effect of different factors on the stopping performance of the tires. (GA)

  15. Handling of high pour point West African crude oils

    SciTech Connect

    Irani, C.; Zajac, J.

    1982-02-01

    Problems related with the transportation of two high pour point west African (Zaire and Cabinda) crudes are discussed. Relevant rheological parameters of untreated and treated (chemical additives for pour point depression) crude were determined in the laboratory with a rotational viscometer and these results are presented. In both cases, low concentrations (30 to 50 ppmw) of the chemical additives improved the mobility and reduced the restarting pressure requirements for the crude. On the basis of the rheological evaluation of Cabinda crude, continuous circulation of the crude in the platform storage tank was suggested to field personnel as a means to partially alleviate the transportation problems. 17 refs.

  16. Résolution par éléments finis d'arête des équations de Maxwell dans les problèmes de jonctions et cavités micro-ondes

    NASA Astrophysics Data System (ADS)

    Wong, M. F.; Picon, O.; Fouad Hanna, V.

    1992-11-01

    The finite element method is applied on solving harmonic Maxwell's equations related to planar and waveguide junctions and cavities problems encountered in the design of passive microwave devices. Using edge-elements, elimination of spurious modes is assured and hence reliable and accurate solutions are obtained. Results for two finline discontinuities as well as for a dielectric resonator compared to numerical and experimental ones are presented. La méthode des éléments finis est appliquée à la résolution des équations harmoniques de Maxwell, dans les problèmes de jonctions et de cavités planaires ou en guide d'onde rencontrés dans la conception de dispositifs micro-ondes passifs. L'utilisation d'éléments d'arêtes assure la non-existence de modes non physiques; des solutions stables et précises sont ainsi obtenues. A titre d'exemples, des résultats relatifs à deux discontinuités en ligne à ailettes et à un résonateur diélectrique comparés à des résultats numériques ou expérimentaux sont présentés.

  17. Algorithmes et architectures pour ordinateurs quantiques supraconducteurs

    NASA Astrophysics Data System (ADS)

    Blais, A.

    2003-09-01

    'utilisation de qubits basés sur les jonctions Josephson. On présente entre autres une approche originale pour l'interaction entre qubits. Cette approche est très générale puisqu'elle peut être appliquée à différents designs de qubits. Finalement, on s'intéresse à la lecture des qubits supraconducteurs de flux. Le détecteur suggéré ici a l'avantage de pouvoir être découplé du qubit lorsqu'il n'y a pas de mesure en cours.

  18. 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.

  19. Drafting distance in swimming.

    PubMed

    Chatard, Jean-Claude; Wilson, Barry

    2003-07-01

    This study investigates the effect of the distance separating the lead and draft swimmers on the metabolic and hydrodynamic responses of the draft swimmer. A nondrafting swim of 4 min at 95% of the best 1500-m pace for 11 swimmers was compared with swimming in a drafting position at four different distances directly behind another swimmer (0, 50, 100, and 150 cm). Swimming performance was assessed by stroke rate and stroke length; the metabolic response by oxygen uptake, heart rate, and blood lactate; and the rating of perceived exertion by the Borg scale. Passive drag was assessed at these drafting distances by passive towing. Then, passive drag was measured in six swimmers towed in six lateral drafting positions, with swimmers separated by approximately 40 cm, and then measured in two positions at the rear of the lead swimmer with a reduced lateral distance between swimmers of 50 and 0 cm. Oxygen uptake, heart rate, blood lactate, rating of perceived exertion, and stroke rate were significantly reduced and stroke length was significantly increased in all drafting positions compared with the nondrafting position. For drag, the most advantageous drafting distances were 0 and 50 cm back from the toes of the lead swimmer. Drag was reduced by 21% and 20%, respectively. In lateral drafting, drag was significantly reduced by 6% and 7%, respectively, at 50 and 100 cm back from the hands of the lead swimmer. Swimming behind another swimmer at a distance between 0 and 50 cm back from the toes was the most advantageous, whereas in lateral drafting the optimal distance was 50-100 cm back from the hands of the lead swimmer.

  20. Distance Education: A Cost Analysis.

    ERIC Educational Resources Information Center

    Jones, Judy I.; And Others

    This report provides administrators, school boards, and policymakers with data to help them in the decision making process related to distance education systems. A literature review covers theories of distance education, distance education today, the economics of distance education, distance education and technology, transmission systems, and…

  1. 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.

  2. The Cepheid distance scale

    NASA Technical Reports Server (NTRS)

    Madore, Barry F.; Freedman, Wendy L.

    1991-01-01

    Developments concerning the period-luminosity (PL) relation for classical Cepheids are discussed with particular emphasis on the fact that Cepheids continue to provide the most homogeneous and reliable set of distances to many nearby galaxies. Observational programs relating to extragalactic Cepheids are also reviewed, and new distances and reddenings to individual galaxies are determined from these data using multiwavelength PL relations, based for the first time on self-consistent calibrating data sets. Three recent promising secondary extragalactic distance indicators (Tully-Fisher, planetary nebula luminosity functions, and surface-brightness fluctuations) tie their zero points to the Cepheid distance scale and give globally consistent values for the Hubble constant of about 80 km/sec/Mpc. Tying the Faber-Jackson relation and the supernova distance scales to the Leo and Virgo clusters yields similar results. Such a value for the Hubble constant is marginally inconsistent with new estimates of the ages of globular clusters, and it may prove to be a serious problem for standard cold-dark-matter models of the universe.

  3. Optimal flight initiation distance.

    PubMed

    Cooper, William E; Frederick, William G

    2007-01-07

    Decisions regarding flight initiation distance have received scant theoretical attention. A graphical model by Ydenberg and Dill (1986. The economics of fleeing from predators. Adv. Stud. Behav. 16, 229-249) that has guided research for the past 20 years specifies when escape begins. In the model, a prey detects a predator, monitors its approach until costs of escape and of remaining are equal, and then flees. The distance between predator and prey when escape is initiated (approach distance = flight initiation distance) occurs where decreasing cost of remaining and increasing cost of fleeing intersect. We argue that prey fleeing as predicted cannot maximize fitness because the best prey can do is break even during an encounter. We develop two optimality models, one applying when all expected future contribution to fitness (residual reproductive value) is lost if the prey dies, the other when any fitness gained (increase in expected RRV) during the encounter is retained after death. Both models predict optimal flight initiation distance from initial expected fitness, benefits obtainable during encounters, costs of escaping, and probability of being killed. Predictions match extensively verified predictions of Ydenberg and Dill's (1986) model. Our main conclusion is that optimality models are preferable to break-even models because they permit fitness maximization, offer many new testable predictions, and allow assessment of prey decisions in many naturally occurring situations through modification of benefit, escape cost, and risk functions.

  4. STEEL BEAMS FOR FIRST FLOOR BEING READIED FOR CONCRETE POUR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STEEL BEAMS FOR FIRST FLOOR BEING READIED FOR CONCRETE POUR UNDER WEATHER SHELTER DURING COLD WINTER. NOTE ABUNDANCE OF BEAMS; THE FLOOR WILL SUPPORT HEAVY LOADS. INL NEGATIVE NO. 1175. Unknown Photographer, 12/20/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. Workmen and Crawler Crane pouring roof slab and parapet wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Workmen and Crawler Crane pouring roof slab and parapet wall of building - looking northwest. Taken Nov. 15, 1929. 14th Naval District Photo Collection Item No. 7165 - U.S. Naval Base, Pearl Harbor, Exterior Cranes, Waterfront Crane Track System, Pearl City, Honolulu County, HI

  6. Le sumatriptan intranasal pour la migraine chez les enfants

    PubMed Central

    Goldman, Ran D.; Meckler, Garth D.

    2015-01-01

    Résumé Question Je vois de plus en plus d’enfants et d’adolescents qui souffrent de céphalées pouvant se classer dans la catégorie des migraines. J’ai fait des lectures sur le sumatriptan par voie intranasale comme thérapie abortive. Est-ce un traitement efficace? Réponse La migraine aiguë chez les enfants et les adolescents est fréquente et difficile à traiter. Le sumatriptan intranasal est une option sûre et généralement efficace pour les enfants et les adolescents. La dose actuellement recommandée est de 20 mg pour les enfants qui pèsent plus de 40 kg et de 10 mg pour ceux dont le poids se situe entre 20 et 39 kg. Il faudrait faire des études de plus grande envergure pour contrecarrer les limitations des échantillons de petite taille et mieux comprendre la faible concentration plasmique et les effets placebo observés dans les études jusqu’à présent.

  7. First Concrete Poured for NSLS-II Ring Building

    SciTech Connect

    2009-07-20

    The first bits of the National Synchrotron Light Source II (NSLS-II) ring building are now taking shape after the concrete-pouring process for the new, world-class facility began on Monday, July 20. Once complete, the 400,000 square-foot building will house the accelerator ring, the largest component of the machine.

  8. Theoretical Principles of Distance Education.

    ERIC Educational Resources Information Center

    Keegan, Desmond, Ed.

    This book contains the following papers examining the didactic, academic, analytic, philosophical, and technological underpinnings of distance education: "Introduction"; "Quality and Access in Distance Education: Theoretical Considerations" (D. Randy Garrison); "Theory of Transactional Distance" (Michael G. Moore);…

  9. Distance estimation in vista space.

    PubMed

    Daum, S Oliver; Hecht, Heiko

    2009-07-01

    Although distance estimation has been extensively studied in the laboratory, our ability to judge large distances in the field is not well researched. We challenge the notion that large distances are uniformly underestimated. We presented different targets to observers at distances ranging from 25 to 500 m to obtain egocentric distance judgments in natural environments. Three experiments showed that observers tend to underestimate distances below 75 m in a large open field, whereas they overestimate farther distances. Both the eye height of the observer and the size of the target also influenced distance estimation. We conclude that the notion of a uniform vista space has to be reconceived.

  10. 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…

  11. 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…

  12. Distance Learning Case Studies.

    ERIC Educational Resources Information Center

    Barker, Bruce O.

    The Office of Technology Assessment authorized a series of case studies in 1989 to investigate how technologies, services, and programs are implemented in distance education projects. The studies were also intended to look at the role of local, state, and federal agencies, and other public and private entities in providing educational services to…

  13. 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…

  14. 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…

  15. Learning across Distance

    ERIC Educational Resources Information Center

    Cowan, Kristina

    2009-01-01

    A 2008 report, "Keeping Pace with K-12 Online Learning," commissioned by North American Council for Online Learning (NACOL) and others, defines online learning as "teacher-led education that takes place over the Internet, with the teacher and student separated geographically." The term "distance learning" includes online education, but is…

  16. Focus on Distance Education.

    ERIC Educational Resources Information Center

    Grenzky, Janet; Maitland, Christine

    2001-01-01

    As a followup to a survey of distance education faculty, the National Education Association conducted two 3-hour focus groups with 12 higher education faculty members in June 2000. The purpose of the groups was to gain more understanding of the complexity of feelings and opinions expressed in a telephone survey conducted in March 2000. The…

  17. 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…

  18. On Defining Distance Education.

    ERIC Educational Resources Information Center

    Rumble, Greville

    1989-01-01

    Reviews past definitions of distance education and offers a new five-part definition of the concept. Topics discussed include the roles of the teachers and students; physical separation of teachers and learners; the influence of an educational organization; communication between teachers and students; and the use of technical media. (22…

  19. 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…

  20. Long-Distance Learning.

    ERIC Educational Resources Information Center

    Charron, Elisabeth; Obbink, Kim

    1993-01-01

    Discusses the following questions in choosing distance education courses: Will I be able to "talk" with the instructor? Will I be able to talk with other course participants? Does the course include laboratories or other hands-on experiences? What equipment will I need to participate? What technical assistance will be available? Who is the course…

  1. Long Distance Learning.

    ERIC Educational Resources Information Center

    Villeneuve, Phyllis, Ed.

    1997-01-01

    This report, from the Faculty Association of Community and Technical Colleges (FACTC) in Washington, focuses on various distance learning courses offered by the state's two-year colleges. The report contains 16 articles from faculty members and students, including: (1) "The Emperor's New Tutor: A Confession" (Sydney Wallace Stegall); (2)…

  2. 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…

  3. 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…

  4. Distance Learning's Growing Reach.

    ERIC Educational Resources Information Center

    Walsh, John; Reese, Bob

    1995-01-01

    Examines the use of videoconferencing and video broadcasts for distance learning and presents examples: the Georgia Statewide Academic and Medical System, California State University System, Kansas City Education Network, Impact North Carolina, the School of Visual Arts in Manhattan, National Technological University, GALAXY Classroom, and…

  5. 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…

  6. ESP and Distance Learning.

    ERIC Educational Resources Information Center

    Boyle, Ron

    1994-01-01

    Distance learning (DL) is proposed as one means of providing in-session language classes for non-native-speaking postgraduate students at English-medium universities. A DL preparatory language program at the Asian Institute of Technology in Bangkok is described. (48 references) (Author/LB)

  7. Learning across Distance

    ERIC Educational Resources Information Center

    Cowan, Kristina

    2009-01-01

    A 2008 report, "Keeping Pace with K-12 Online Learning," commissioned by North American Council for Online Learning (NACOL) and others, defines online learning as "teacher-led education that takes place over the Internet, with the teacher and student separated geographically." The term "distance learning" includes online education, but is…

  8. Peterson's Distance Learning 1997.

    ERIC Educational Resources Information Center

    Peterson's Guides, Inc., Princeton, NJ.

    This guide provides profiles of distance learning programs in postsecondary education institutions throughout the United States, alphabetically by institution. The descriptions contain information on program access, media used (e.g., videocassette, correspondence, television, radio, teleconferencing), student services offered, application process,…

  9. 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…

  10. Determining average yarding distance.

    Treesearch

    Roger H. Twito; Charles N. Mann

    1979-01-01

    Emphasis on environmental and esthetic quality in timber harvesting has brought about increased use of complex boundaries of cutting units and a consequent need for a rapid and accurate method of determining the average yarding distance and area of these units. These values, needed for evaluation of road and landing locations in planning timber harvests, are easily and...

  11. 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 study…

  12. Celebrating Distance Teaching Innovations: The Certificate in Distance Teaching.

    ERIC Educational Resources Information Center

    Boylan, Colin; Tuovinen, Juhani

    Charles Sturt University (Riverina, Australia) has initiated the Certificate in Distance Teaching course for rural teachers working in a distance education setting to extend their understandings about rural and distance education topics. Two semester-long subjects constitute the course: pedagogy of distance teaching and organization of distance…

  13. 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…

  14. A Systematic Review of the Free-Pour Assessment: Implications for Research, Assessment and Intervention.

    PubMed

    Schultz, Nicole R; Kohn, Carolynn S; Schmerbauch, Megan; Correia, Christopher J

    2017-03-13

    Excessive alcohol consumption is a major concern. Alcohol consumption data are typically collected via self-report questionnaires. However, research has suggested that individuals are unable to identify a standard drink size and that their self-report may be influenced by certain environmental conditions, calling into question the reliability and validity of self-report. The free-pour is an objective measure that may provide a clearer picture of current alcohol consumption trends, individuals' knowledge of standard drink sizes, and accuracy of self-report. This systematic review of existing free-pour assessment methods suggests that individuals are unable to identify and pour standard drink sizes, with the largest discrepancies occurring for liquor and wine pours and pours into larger and wider glasses. Additional variables that appear to influence pouring behavior are gender, pouring location (e.g., home or laboratory), pouring task (e.g., selecting a line or physically pouring), and drinking history; however, additional research is necessary to better understand the effects of these variables on pouring behavior. These findings have important implications for the accuracy of self-report measures, as well as clinical implications for alcohol use screenings, alcohol education courses, and brief interventions for alcohol use. The systematic review concludes with recommendations for practical applications and future research of the free-pour assessment. (PsycINFO Database Record

  15. Distance between images

    NASA Technical Reports Server (NTRS)

    Gualtieri, J. A.; Le Moigne, J.; Packer, C. V.

    1992-01-01

    Comparing two binary images and assigning a quantitative measure to this comparison finds its purpose in such tasks as image recognition, image compression, and image browsing. This quantitative measurement may be computed by utilizing the Hausdorff distance of the images represented as two-dimensional point sets. In this paper, we review two algorithms that have been proposed to compute this distance, and we present a parallel implementation of one of them on the MasPar parallel processor. We study their complexity and the results obtained by these algorithms for two different types of images: a set of displaced pairs of images of Gaussian densities, and a comparison of a Canny edge image with several edge images from a hierarchical region growing code.

  16. The sound of distance.

    PubMed

    Rabaglia, Cristina D; Maglio, Sam J; Krehm, Madelaine; Seok, Jin H; Trope, Yaacov

    2016-07-01

    Human languages may be more than completely arbitrary symbolic systems. A growing literature supports sound symbolism, or the existence of consistent, intuitive relationships between speech sounds and specific concepts. Prior work establishes that these sound-to-meaning mappings can shape language-related judgments and decisions, but do their effects generalize beyond merely the linguistic and truly color how we navigate our environment? We examine this possibility, relating a predominant sound symbolic distinction (vowel frontness) to a novel associate (spatial proximity) in five studies. We show that changing one vowel in a label can influence estimations of distance, impacting judgment, perception, and action. The results (1) provide the first experimental support for a relationship between vowels and spatial distance and (2) demonstrate that sound-to-meaning mappings have outcomes that extend beyond just language and can - through a single sound - influence how we perceive and behave toward objects in the world. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Influence of delayed pouring on irreversible hydrocolloid properties.

    PubMed

    Rodrigues, Stéfani Becker; Augusto, Carolina Rocha; Leitune, Vicente Castelo Branco; Samuel, Susana Maria Werner; Collares, Fabrício Mezzomo

    2012-01-01

    The aim of this study was to evaluate the physical properties of irreversible hydrocolloid materials poured immediately and after different storage periods. Four alginates were tested: Color Change (Cavex); Hydrogum (Zhermack); Hydrogum 5 (Zhermack); and Hydro Print Premium (Coltene). Their physical properties, including the recovery from deformation (n = 3), compressive strength (n = 3), and detail reproduction and gypsum compatibility (n = 3), were analyzed according to ANSI/ADA specification no. 18. Specimens were stored at 23ºC and humidity and were then poured with gypsum immediately and after 1, 2, 3, 4, and 5 days. The data were analyzed by two-way analysis of variance (ANOVA) and Tukey's test at p < 0.05. All of the alginate impression materials tested exhibited detail reproduction and gypsum compatibility at all times. Hydro Print Premium and Hydrogum 5 showed recovery from deformation, as established by ANSI/ADA specification no. 18, after 5 days of storage. As the storage time increased, the compressive strength values also increased. Considering the properties of compounds' recovery from deformation, compressive strength, and detail reproduction and gypsum compatibility, irreversible hydrocolloids should be poured immediately.

  2. 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

  3. 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

  4. 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.

  5. Distance Metric Tracking

    DTIC Science & Technology

    2016-03-02

    520, 2004. 16 [12] E.C. Hall and R.M. Willett. Online convex optimization in dynamic environ- ments. Selected Topics in Signal Processing, IEEE Journal...Conference on Machine Learning, pages 1160–1167. ACM, 2008. [25] Eric P Xing, Michael I Jordan, Stuart Russell, and Andrew Y Ng. Distance metric...whereBψ is any Bregman divergence and ηt is the learning rate parameter. From ( Hall & Willett, 2015) we have: Theorem 1. G` = max θ∈Θ,`∈L ‖∇f(θ)‖ φmax = 1

  6. Guides d'ondes infrarouges pour applications en télécommunications, capteurs chimiques et biochimiques

    NASA Astrophysics Data System (ADS)

    Smektala, F.; Bureau, B.; Adam, J. L.; Lucas, J.

    2002-06-01

    Les énergies de phonons élevés des verres à base de silice limitent leurs applications dans l'infrarouge. Il devient donc incontournable de créer des verres à plus faible énergie de phonons pour développer une optique passive guidée opérationnelle dans l'IR moyen et pour réaliser de nouveaux guide d'ondes optiques activés par des lanthanides pouvant jouer le rôle soit d'amplificateurs optiques soit de fibres lasers. Les compositions de verres stables répondant à ces critères sont exceptionnelles et appartiennent aux familles chimiques des fluorures et des chalcogénures. Les verres de fluorures, convenablement dopés par des terres rares, ont permis la réalisation d'amplificateurs optiques opérant dans la fenêtre télecom de la silice (1.3 μm avec le praséodyme, 1.45 μm avec le thulium et 1.55 μm avec l'erbium. Les verres de chalcogénures permettent la réalisation de fibres opérationnelles jusqu'à 12 μm mais seulement pour des applications courtes distances telles que le transport d'énergie moyenne, la radiométrie à l'ambiante et la spectrométrie IR déportée par fibre optique de molécules chimiques ou de tissus biologiques.

  7. 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.

  8. 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.

  9. The effect of pouring time on the dimensional accuracy of casts made from different irreversible hydrocolloid impression materials.

    PubMed

    Wadhwa, Supneet Singh; Mehta, Richa; Duggal, Nidhi; Vasudeva, Kamlesh

    2013-07-01

    To determine the time dependent accuracy of casts made from three different irreversible hydrocolloids. The effect of delayed pouring on the accuracy of three different irreversible hydrocolloid impression materials - Regular set CA 37(Cavex, The Netherlands), regular set chromatic (Jeltrate, Dentsply), and fast set (Hydrogum soft, Zhermack Clinical) was investigated. A brass master die that contained two identical posts simulating two complete crown-tapered abutment preparations with reference grooves served as a standardized master model. A total of 120 impressions were made using specially prepared stock-perforated brass tray with 40 impressions of each material. The impressions were further sub-grouped according to four different storage time intervals: 0 min (immediately), 12 min, 30 min, and 1 h. The impressions were stored at room temperature in a zip-lock plastic bag. Interabutment and intraabutment distances were measured in the recovered stone dies (Type IV, Kalrock) using a profile projector with an accuracy of 0.001 mm. The data so obtained was analyzed statistically. Results of this study showed no statistically significant differences in the accuracy of casts obtained at different time intervals. Because it is not always possible to pour the impression immediately in routine clinical practice, all irreversible hydrocolloid materials studied could be stored in a zip-lock plastic bag for upto 1 h without any significant distortion.

  10. The effect of pouring time on the dimensional accuracy of casts made from different irreversible hydrocolloid impression materials

    PubMed Central

    Wadhwa, Supneet Singh; Mehta, Richa; Duggal, Nidhi; Vasudeva, Kamlesh

    2013-01-01

    Aims and Objectives: To determine the time dependent accuracy of casts made from three different irreversible hydrocolloids. Materials and Methods: The effect of delayed pouring on the accuracy of three different irreversible hydrocolloid impression materials – Regular set CA 37(Cavex, The Netherlands), regular set chromatic (Jeltrate, Dentsply), and fast set (Hydrogum soft, Zhermack Clinical) was investigated. A brass master die that contained two identical posts simulating two complete crown-tapered abutment preparations with reference grooves served as a standardized master model. A total of 120 impressions were made using specially prepared stock-perforated brass tray with 40 impressions of each material. The impressions were further sub-grouped according to four different storage time intervals: 0 min (immediately), 12 min, 30 min, and 1 h. The impressions were stored at room temperature in a zip-lock plastic bag. Interabutment and intraabutment distances were measured in the recovered stone dies (Type IV, Kalrock) using a profile projector with an accuracy of 0.001 mm. The data so obtained was analyzed statistically. Results: Results of this study showed no statistically significant differences in the accuracy of casts obtained at different time intervals. Conclusion: Because it is not always possible to pour the impression immediately in routine clinical practice, all irreversible hydrocolloid materials studied could be stored in a zip-lock plastic bag for upto 1 h without any significant distortion. PMID:24124296

  11. Jets from a Distance

    NASA Image and Video Library

    2017-07-17

    Enceladus' intriguing south-polar jets are viewed from afar, backlit by sunlight while the moon itself glows softly in reflected Saturn-shine. Observations of the jets taken from various viewing geometries provide different insights into these remarkable features. Cassini has gathered a wealth of information in the hopes of unraveling the mysteries of the subsurface ocean that lurks beneath the moon's icy crust. This view looks toward the Saturn-facing hemisphere of Enceladus (313 miles or 504 kilometers across). North is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 13, 2017. The view was acquired at a distance of approximately 502,000 miles (808,000 kilometers) from Enceladus and at a sun-Enceladus-spacecraft, or phase, angle of 176 degrees. Image scale is 3 miles (5 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21338

  12. 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.

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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.

  18. Simulations numériques de différentes méthodes d'éléments finis pour les problèmes de contact avec frottementNumerical implementation of different finite element methods for contact problems with friction

    NASA Astrophysics Data System (ADS)

    Baillet, Laurent; Sassi, Taoufik

    2003-11-01

    In this Note, we propose an efficient numerical treatment for solving contact problems with friction between deformable bodies. The discretized normal and tangential constraints at the candidate contact interface are expressed by using either continuous piecewise linear or piecewise constant Lagrange multipliers. Several numerical studies corresponding to this choice are achieved in the PLAST2 code. To cite this article: L. Baillet, T. Sassi, C. R. Mecanique 331 (2003).

  19. Supportive learning in distance education.

    PubMed

    Lawton, S

    1997-05-01

    This paper argues that tutorial support should enhance the learning experience of students who enrol on a distance education programme. A rationale for such support is given as well as a definition of support for distance learners. The complex role of the tutor in distance learning is described which suggests the need for tutor preparation, particularly for tutors adapting to this mode of course delivery. The paper reports on two existing models used within distance education which have focused on the outcome of study. The paper introduces an alternative model of supportive learning which focuses on the development of the educational experience throughout the length of a distance-learning course.

  20. CONCRETE POURS HAVE PRODUCED A REINFORCED SUPPORT BASE FOR MTR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONCRETE POURS HAVE PRODUCED A REINFORCED SUPPORT BASE FOR MTR REACTOR. PIPE TUNNEL IS UNDER CONSTRUCTION AT CENTER OF VIEW. PIPES WILL CARRY RADIOACTIVE WATER FROM REACTOR TO WATER PROCESS BUILDING. CAMERA LOOKS SOUTH INTO TUNNEL ALONG WEST SIDE OF REACTOR BASE. TWO CAISSONS ARE AT LEFT SIDE OF VIEW. NOTE "WINDOW" IN SOUTH FACE OF REACTOR BASE AND ALSO GROUP OF PENETRATIONS TO ITS LEFT. INL NEGATIVE NO. 733. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. Avalanche Segregation of Granular Media Poured into a Hele-Shaw Cell

    NASA Astrophysics Data System (ADS)

    Kakalios, J.; Koeppe, J.; Enz, M.

    1997-03-01

    When an initially homogeneous mixture of sand and sugar is poured into a "quasi-two-dimensional" Hele Shaw cell, that is, two vertical transparent plates held a narrow distance apart, the resulting pile forms alternating segregated layers (H. A. Makse, S. Havlin, P. B. King and H. E. Stanley, to be published.). We report studies of this "avalanche segregation" of granular mixtures as the plate separation and flow rates are systematically varied. The degree of segregation and wavelength are studied using digital images taken with a CCD camera and Fourier transformed to obtain the structure function of the banding pattern. As the plate separation is increased, for a given flow rate both the degree of segregation and wavelength (determined by the amplitude and position of the peak in the structure function) decreases. For intermediate plate separations, a pairing of adjacent segregated bands is observed. These results are discussed in terms of a recent model proposed by Boutreux and de Gennes (T. Boutreux and P.-G. de Gennes, J. Phys.I France 6, 1295 (1996)).

  2. A matter of distance

    NASA Image and Video Library

    2017-04-24

    In space, being outshone is an occupational hazard. This NASA/ESA Hubble Space Telescope image captures a galaxy named NGC 7250. Despite being remarkable in its own right — it has bright bursts of star formation and recorded supernova explosions — it blends into the background somewhat thanks to the gloriously bright star hogging the limelight next to it. This bright object is a single and little-studied star named TYC 3203-450-1, located in the constellation of Lacerta (The Lizard), much closer than the much more distant galaxy. Only this way a normal star can outshine an entire galaxy, consisting of billions of stars. Astronomers studying distant objects call these stars “foreground stars” and they are often not very happy about them, as their bright light is contaminating the faint light from the more distant and interesting objects they actually want to study. In this case TYC 3203-450-1 million times closer than NGC 7250 which lies over 45 million light-years away from us. Would the star be the same distance as NGC 7250, it would hardly be visible in this image.

  3. extinction-distances: Estimating distances to dark clouds

    NASA Astrophysics Data System (ADS)

    Foster, Jonathan

    2017-08-01

    Extinction-distances uses the number of foreground stars and a Galactic model of the stellar distribution to estimate the distance to dark clouds. It exploits the relatively narrow range of intrinsic near-infrared colors of stars to separate foreground from background stars. An advantage of this method is that the distribution of stellar colors in the Galactic model need not be precisely correct, only the number density as a function of distance from the Sun.

  4. Conception d'un circuit d'etouffement pour photodiodes a avalanche en mode geiger pour integration heterogene 3d

    NASA Astrophysics Data System (ADS)

    Boisvert, Alexandre

    Le Groupe de Recherche en Appareillage Medical de Sherbrooke (GRAMS) travaille actuellement sur un programme de recherche portant sur des photodiodes a avalanche mono-photoniques (PAMP) operees en mode Geiger en vue d'une application a la tomographie d'emission par positrons (TEP). Pour operer dans ce mode; la PAMP, ou SPAD selon l'acronyme anglais (Single Photon Avalanche Diode), requiert un circuit d'etouffement (CE) pour, d'une part, arreter l'avalanche pouvant causer sa destruction et, d'autre part. la reinitialiser en mode d'attente d'un nouveau photon. Le role de ce CE comprend egalement une electronique de communication vers les etages de traitement avance de signaux. La performance temporelle optimale du CE est realisee lorsqu'il est juxtapose a la PAMP. Cependant, cela entraine une reduction de la surface photosensible ; un element crucial en imagerie. L'integration 3D, a base d'interconnexions verticales, offre une solution elegante et performante a cette problematique par l'empilement de circuits integres possedant differentes fonctions (PAMP, CE et traitement avance de signaux). Dans l'approche proposee, des circuits d'etouffement de 50 pm x 50 pm realises sur une technologie CMOS 130 mn 3D Tezzaron, contenant chacun 112 transistors, sont matrices afin de correspondre a une matrice de PAMP localisee sur une couche electronique superieure. Chaque circuit d'etouffement possede une gigue temporelle de 7,47 ps RMS selon des simulations faites avec le logiciel Cadence. Le CE a la flexibilite d'ajuster les temps d'etouffement et de recharge pour la PAMP tout en presentant une faible consommation de puissance (~ 0,33 mW a 33 Mcps). La conception du PAMP necessite de supporter des tensions superieures aux 3,3 V de la technologie. Pour repondre a ce probleme, des transistors a drain etendu (DEMOS) ont ete realises. En raison de retards de production par Ies fabricants, les circuits n'ont pu etre testes physiquement par des mesures. Les resultats de ce memoire

  5. New distances to RAVE stars

    NASA Astrophysics Data System (ADS)

    Binney, J.; Burnett, B.; Kordopatis, G.; McMillan, P. J.; Sharma, S.; Zwitter, T.; Bienaymé, O.; Bland-Hawthorn, J.; Steinmetz, M.; Gilmore, G.; Williams, M. E. K.; Navarro, J.; Grebel, E. K.; Helmi, A.; Parker, Q.; Reid, W. A.; Seabroke, G.; Watson, F.; Wyse, R. F. G.

    2014-01-01

    Probability density functions (pdfs) are determined from new stellar parameters for the distance moduli of stars for which the RAdial Velocity Experiment (RAVE) has obtained spectra with S/N ≥ 10. Single-Gaussian fits to the pdf in distance modulus suffice for roughly half the stars, with most of the other half having satisfactory two-Gaussian representations. As expected, early-type stars rarely require more than one Gaussian. The expectation value of distance is larger than the distance implied by the expectation of distance modulus; the latter is itself larger than the distance implied by the expectation value of the parallax. Our parallaxes of Hipparcos stars agree well with the values measured by Hipparcos, so the expectation of parallax is the most reliable distance indicator. The latter are improved by taking extinction into account. The effective temperature-absolute magnitude diagram of our stars is significantly improved when these pdfs are used to make the diagram. We use the method of kinematic corrections devised by Schönrich, Binney and Asplund to check for systematic errors for general stars and confirm that the most reliable distance indicator is the expectation of parallax. For cool dwarfs and low-gravity giants, <ϖ> tends to be larger than the true distance by up to 30 per cent. The most satisfactory distances are for dwarfs hotter than 5500 K. We compare our distances to stars in 13 open clusters with cluster distances from the literature and find excellent agreement for the dwarfs and indications that we are overestimating distances to giants, especially in young clusters.

  6. The efficacy of pour-on ivermectin in bison (Bison bison)

    PubMed Central

    Woodbury, Murray R.; Lewis, W. Roy

    2011-01-01

    To test the effectiveness of pour-on ivermectin in parasitized bison, changes in fecal parasite egg counts after treatment with ivermectin injectable or pour-on preparations were compared to a negative control group. There was no difference between the two ivermectin groups, and both forms of ivermectin were effective in reducing fecal parasite egg counts in parasitized bison. PMID:22043076

  7. Shape of glass and amount of alcohol poured: comparative study of effect of practice and concentration.

    PubMed

    Wansink, Brian; van Ittersum, Koert

    2005-12-24

    To determine whether people pour different amounts into short, wide glasses than into tall, slender ones. College students practised pouring alcohol into a standard glass before pouring into larger glasses; bartenders poured alcohol for four mixed drinks either with no instructions or after being told to take their time. University town and large city, United States. 198 college students and 86 bartenders. Volume of alcohol poured into short, wide and tall, slender glasses. Aiming to pour a "shot" of alcohol (1.5 ounces, 44.3 ml), both students and bartenders poured more into short, wide glasses than into tall slender glasses (46.1 ml v 44.7 ml and 54.6 ml v 46.4 ml, respectively). Practice reduced the tendency to overpour, but not for short, wide glasses. Despite an average of six years of experience, bartenders poured 20.5% more into short, wide glasses than tall, slender ones; paying careful attention reduced but did not eliminate the effect. To avoid overpouring, use tall, narrow glasses or ones on which the alcohol level is premarked. To avoid underestimating the amount of alcohol consumed, studies using self reports of standard drinks should ask about the shape of the glass.

  8. Approximating subtree distances between phylogenies.

    PubMed

    Bonet, Maria Luisa; St John, Katherine; Mahindru, Ruchi; Amenta, Nina

    2006-10-01

    We give a 5-approximation algorithm to the rooted Subtree-Prune-and-Regraft (rSPR) distance between two phylogenies, which was recently shown to be NP-complete. This paper presents the first approximation result for this important tree distance. The algorithm follows a standard format for tree distances. The novel ideas are in the analysis. In the analysis, the cost of the algorithm uses a "cascading" scheme that accounts for possible wrong moves. This accounting is missing from previous analysis of tree distance approximation algorithms. Further, we show how all algorithms of this type can be implemented in linear time and give experimental results.

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. Interactive Television and Distance Learning.

    ERIC Educational Resources Information Center

    Rees, Fred J.; Downs, Dennis A.

    1995-01-01

    Describes the origins and operations of the Iowa Communications Network, an interactive distance learning program. Presents several examples of how the network can benefit music educators in college and K-12 institutions. Maintains that the system can be a model for similar distance music education networks. (CFR)

  15. Blogging for the Distance Librarian

    ERIC Educational Resources Information Center

    Pival, Paul R.

    2005-01-01

    Based on user lookups, "Merriam-Webster Online "proclaimed "Blog" the word of the year for 2004. Distance librarianship, until mid-way through 2004, was a subject that was underrepresented in the blogosphere. The inception of a blog called "The Distant Librarian: Comments on the World of Distance Librarianship" is chronicled in this article, along…

  16. 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.

  17. Distance Education and Developing Countries.

    ERIC Educational Resources Information Center

    Daniel, John S.

    The purpose of this paper is to give those who work in distance education a better awareness of the factors at work in developing nations and to help those whose profession is national development gain a fuller understanding of distance education. It begins with a discussion of the process of national development which focuses on the factors that…

  18. Quality Content in Distance Education

    ERIC Educational Resources Information Center

    Yildiz, Ezgi Pelin; Isman, Aytekin

    2016-01-01

    In parallel with technological advances in today's world of education activities can be conducted without the constraints of time and space. One of the most important of these activities is distance education. The success of the distance education is possible with content quality. The proliferation of e-learning environment has brought a need for…

  19. 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…

  20. 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…

  1. 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…

  2. Distance Learning: The Essential Guide.

    ERIC Educational Resources Information Center

    Williams, Marcia L.; Paprock, Kenneth; Covington, Barbara

    Intended for individuals engaged in open and distance learning activities, this guide is designed with an applications focus that provides a "quick start" for immediate work needs. Built on an intuitive set of "How do I" questions, the book presents the foundation needed to teach from a distance. The format is a multimodel approach, combining…

  3. 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.

  4. 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…

  5. 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…

  6. 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…

  7. Examining Distance Education in Turkey.

    ERIC Educational Resources Information Center

    McIsaac, Marina Stock; And Others

    1988-01-01

    Describes the distance education program at Anadolu University in Turkey and compares its problems and solutions with similar distance programs in other Asian countries. A brief history is presented, enrollment figures are given, and future directions are described. (Author/LRW)

  8. 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…

  9. Is Distance Education for You?

    ERIC Educational Resources Information Center

    Walter, Laura M.

    2004-01-01

    Millions of Americans are currently enrolled in distance learning institutions. The flexible study schedules, independent learning, and self-paced courses are attracting more students than ever. Those interested in enrolling in a distance education school, probably have a lot of questions. Choosing the right school is an important decision, and…

  10. Distance Education: A Cost Analysis.

    ERIC Educational Resources Information Center

    Jones, Judy I.; Simonson, Michael

    The costs of three types of transmission technology in distance education are compared, and the costs for equipping and installing a distance education classroom are estimated. Two of the technologies--fiber optics and microwave--deliver two-way, full motion video and two-way audio. The third technology, compressed video, also delivers two-way…

  11. 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…

  12. 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)

  13. 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…

  14. 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…

  15. Distance Education for Continuing Education.

    ERIC Educational Resources Information Center

    Sharma, Motilal

    The role of distance education as a vehicle for delivering continuing education in Asia was examined from the following standpoints: facilitating development amidst poverty; making human resource development the prime strategy; overcoming the stagnation of education amidst wrenching change; and using distance education to accomplish those…

  16. 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…

  17. 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

  18. Reducing the distance in distance-caregiving by technology innovation

    PubMed Central

    Benefield, Lazelle E; Beck, Cornelia

    2007-01-01

    Family caregivers are responsible for the home care of over 34 million older adults in the United States. For many, the elder family member lives more than an hour’s distance away. Distance caregiving is a growing alternative to more familiar models where: 1) the elder and the family caregiver(s) may reside in the same household; or 2) the family caregiver may live nearby but not in the same household as the elder. The distance caregiving model involves elders and their family caregivers who live at some distance, defined as more than a 60-minute commute, from one another. Evidence suggests that distance caregiving is a distinct phenomenon, differs substantially from on-site family caregiving, and requires additional assistance to support the physical, social, and contextual dimensions of the caregiving process. Technology-based assists could virtually connect the caregiver and elder and provide strong support that addresses the elder’s physical, social, cognitive, and/or sensory impairments. Therefore, in today’s era of high technology, it is surprising that so few affordable innovations are being marketed for distance caregiving. This article addresses distance caregiving, proposes the use of technology innovation to support caregiving, and suggests a research agenda to better inform policy decisions related to the unique needs of this situation. PMID:18044143

  19. The art of descrying distance.

    PubMed

    Niall, K K

    1999-09-01

    How naive can one experiment be? Imagine asking observers to judge distance -- yes, literally asking them. And in asking them, no visual evoked potentials were measured, and changes in blood flow to the occipital cortex were ignored. But serendipity occurs even to the well-prepared: One's best thought for a new experiment can prove to be one's first unbiased, uncomplicated thought.Here's a cursory review of the events: A number of observers were asked to judge distances between marked posts in a field at night. They made their judgments with the help of night vision goggles (NVG). At first the observers underestimated the distances on average. Then an experimenter began to correct the observers after each judgment. The observers' judgments of distance became accurate. On average, the observers began to estimate those distances accurately. Is this and incredible story or a difficult one?

  20. Predicting the Effect of Pouring Temperature on the Crystallite Density, Remelting, and Crystal Growth Kinetics in the Solidification of Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Ferguson, J. B.; Tabandeh-Khorshid, Meysam; Mantas, John C.; Rohatgi, Pradeep K.; Cho, Kyu; Kim, Chang-Soo

    2014-08-01

    In the present work, we developed an analytical model to describe the effect of pouring temperature on the crystallite density, remelting, growth kinetics, and the resultant final grain size for aluminum (Al)-based alloys synthesized using gravity casting. The model predicts that there are three regimes of pouring temperature/grain size-related behavior: (i) at low superheats, grain size is small and relatively constant; (ii) at intermediate levels of superheat, there appears to be a transitional behavior where grain size increases in a rapid, non-linear fashion; and (iii) at high superheats, grain size increases linearly with increasing temperature. This general pattern is expected to be shifted upward as distance from the bottom of the casting increases, which is likely a result of the slower cooling rates and/or longer solidification times with increasing distance from the bottom of the casting. To validate the model, a set of experiments has been conducted using Al-Cu and Al-Si alloys ( i.e., Al-3.0 wt pct Cu, Al-4.5 wt pct Cu, and Al-A356.2 alloys), and the experimental measurements showed consistent results with theoretical predictions.

  1. Caracterisation thermique de modules de refroidissement pour la photovoltaique concentree

    NASA Astrophysics Data System (ADS)

    Collin, Louis-Michel

    Pour rentabiliser la technologie des cellules solaires, une reduction du cout d'exploitation et de fabrication est necessaire. L'utilisation de materiaux photovoltaiques a un impact appreciable sur le prix final par quantite d'energie produite. Une technologie en developpement consiste a concentrer la lumiere sur les cellules solaires afin de reduire cette quantite de materiaux. Or, concentrer la lumiere augmente la temperature de la cellule et diminue ainsi son efficacite. Il faut donc assurer a la cellule un refroidissement efficace. La charge thermique a evacuer de la cellule passe au travers du recepteur, soit la composante soutenant physiquement la cellule. Le recepteur transmet le flux thermique de la cellule a un systeme de refroidissement. L'ensemble recepteur-systeme de refroidissement se nomme module de refroidissement. Habituellement, la surface du recepteur est plus grande que celle de la cellule. La chaleur se propage donc lateralement dans le recepteur au fur et a mesure qu'elle traverse le recepteur. Une telle propagation de la chaleur fournit une plus grande surface effective, reduisant la resistance thermique apparente des interfaces thermiques et du systeme de refroidissement en aval vers le module de refroidissement. Actuellement, aucune installation ni methode ne semble exister afin de caracteriser les performances thermiques des recepteurs. Ce projet traite d'une nouvelle technique de caracterisation pour definir la diffusion thermique du recepteur a l'interieur d'un module de refroidissement. Des indices de performance sont issus de resistances thermiques mesurees experimentalement sur les modules. Une plateforme de caracterisation est realisee afin de mesurer experimentalement les criteres de performance. Cette plateforme injecte un flux thermique controle sur une zone localisee de la surface superieure du recepteur. L'injection de chaleur remplace le flux thermique normalement fourni par la cellule. Un systeme de refroidissement est installe

  2. Soft drink "pouring rights": marketing empty calories to children.

    PubMed

    Nestle, M

    2000-01-01

    Healthy People 2010 objectives call for meals and snacks served in schools to contribute to overall diets that meet federal dietary guidelines. Sales in schools of foods and drinks high in calories and low in nutrients undermine this health objective, as well as participation in the more nutritious, federally sponsored, school lunch programs. Competitive foods also undermine nutrition information taught in the classroom. Lucrative contracts between school districts and soft drink companies for exclusive rights to sell one brand are the latest development in the increasing commercialization of school food. These contracts, intended to elicit brand loyalty among young children who have a lifetime of purchases ahead of them, are especially questionable because they place schools in the position of "pushing" soft drink consumption. "Pouring rights" contracts deserve attention from public health professionals concerned about the nutritional quality of children's diets.

  3. Passeport pour les deux infinis: an educational project in French

    NASA Astrophysics Data System (ADS)

    Arnaud, Nicolas; Descotes-Genon, Sébastien; Kerhoas-Cavata, Sophie; Paul, Jacques; Robert-Esil, Jean-Luc; Royole-Degieux, Perrine

    2016-04-01

    Passeport pour les deux infinis (;Passport for the two infinities;, in short Pass2i) is a French educational project aiming at promoting the physics of the infinitely small (particle physics) and of the infinitely big (cosmology & astrophysics) to high-school teachers and students. It is managed since 2009 by a small team of outreach experts (physicists and engineers) from the CNRS and the CEA. The Pass2i cornerstone is a reversible book - where each side explores one of the two infinities - and which is given for free to science high school teachers who request it, thanks to the support of French funding agencies. The Pass2i non-profit association wants to be a bridge between science and education: training sessions are organized for teachers, educational resources created and made available for download on the Pass2i website (http://www.passeport2i.fr).

  4. VIEW OF THE #67 HOLDING FURNACE POURING AT #04 COPPER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE #67 HOLDING FURNACE POURING AT #04 COPPER STATION IN THE CASTING SHOP. (OTHER UNITS MELT BRASS ALLOYS.) THIS IS THE SOUTHERNMOST FURNACE OF THE FOUR PRESENTLY IN SITU. THE CURRENT CASTING SHOP WAS CONSTRUCTED DURING THE EARLY 1970'S, REPLACING THE ORIGINAL PRE-WWI FACILITY. STATIONS #02, 03, AND 04 EACH CONSIST OF A HOLDER FLANKED BY A PAIR OF 800 KW ELECTRIC MELTERS. THE HOLDER IS REHEATED AT 85,000 LBS. SHAKER BOX, LOCATED AT THE REAR OF EACH MELTER SUPPLY THE MIXTURE OF INGREDIENTS REQUIRED FOR EACH PARTICULAR ALLOY. ONE MEMBER OF THE THREE-MAN CASTING TEAMS IS RESPONSIBLE FOR SHAKING METAL INTO THE MELTERS. IN THE LOWER RIGHT ARE SHOWN THE MOLD STORAGE AREA AND THE FURNACE BUILDERS' AREA FOR CHIPPING AND REBRICKING OFF-LINE UNITS. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  5. VIEW OF THE #67 HOLDING FURNACE POURING AT #04 COPPER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE #67 HOLDING FURNACE POURING AT #04 COPPER STATION IN THE CASTING SHOP. (OTHER UNITS MELT BRASS ALLOYS.) THIS IS THE SOUTHERNMOST FURNACE OF THE FOUR PRESENTLY IN SITU. THE CURRENT CASTING SHOP WAS CONSTRUCTED DURING THE EARLY 1970'S, REPLACING THE ORIGINAL PRE-WWI FACILITY. STATIONS #02,03, AND 04 EACH CONSIST OF A HOLDER FLANKED BY A PAIR OF 800 KW ELECTRIC MELTERS. THE HOLDER IS RATED AT 85,000 LBS. SHAKER BOXES, LOCATED AT THE REAR OF EACH MELTER SUPPLY THE MIXTURE OF INGREDIENTS REQUIRED FOR EACH PARTICULAR ALLOY. ONE MEMBER OF THE THREE-MAN CASTING TEAMS IS RESPONSIBLE FOR SHAKING METAL INTO THE MELTERS. IN THE LOWER RIGHT ARE SHOWN THE MOLD STORAGE AREA AND THE FURNACE BUILDERS' AREA FOR CHIPPING AND REBRICKING OFF-LINE UNITS. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  6. Copolymeric pour-point depressant for diesel fuel

    SciTech Connect

    Ivanov, V.I.; Dadyko, V.A.; Dushechkin, A.P.; Shapkina, L.N.

    1984-03-01

    This article considers the use of a pour-point depressant consisting of a mixture of ethylene with methyl methacrylate (EMMA) and ethylene with vinyl acetate (EVA) to improve the low-temperature indexes of diesel fuels. It is determined that the greatest effect with respect to limiting filterability temperature from the addition of EMMA is achieved with an EVA content of approximately 0.04%. The use of both a copolymer promoting the formation of a large number of crystallization centers (EMMA) and a copolymer that is a good modifier of the wax crystal surface (EVA) leads to a limitation of the crystal growth and preservation of the fine-crystal structure as the fuel temperature is lowered.

  7. Genealogical trees from genetic distances

    NASA Astrophysics Data System (ADS)

    Prignano, L.; Serva, M.

    2009-06-01

    In a population with haploid reproduction any individual has a single parent in the previous generation. If all genealogical distances among pairs of individuals (generations from the closest common ancestor) are known it is possible to exactly reconstruct their genealogical tree. Unfortunately, in most cases, genealogical distances are unknown and only genetic distances are available. The genetic distance between two individuals is measurable from differences in mtDNA (mitochondrial DNA) since in the case of humans or other complex organisms mtDNA is transmitted in a haploid manner. An analogous distance can be also computed for languages where it may be measured from lexical differences, in this case, nevertheless, haploid reproduction is only a raw approximation. Assuming a constant rate of mutation, these genetic distances are random and proportional only on average to genealogical ones. The reconstruction of the genealogical tree from the available genetic distances is forceful imprecise. In this paper we try to quantify the error one may commit in the reconstruction of the tree for different degrees of randomness. The errors may concern both topology of the tree (the branching hierarchy) and, in case of correct topology, the proportions of the tree (length of various branches).

  8. 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.

  9. Synthesis copolymer use to reduce pour point temperature of diamond crude oil

    NASA Astrophysics Data System (ADS)

    Than, Dao Viet; Chuong, Thai Hong; Tuy, Dao Quoc

    2017-09-01

    Diamond oil field is located in Block 01&02 Offshore Vietnam. Crude oil from Diamond Well Head Platform (WHP) is evacuated to FPSO via 20km 10" subsea flexible pipeline. The lowest seabed temperature in the field is 22°C, while the pour point temperature (PPT) of Diamond crude oil is very high (36°C) due to high paraffin content (25%). So studying to research a suitable Pour Point Depressant (PPD) for the crude oil is very important. The PPD must have ability to reduce pour point temperature of crude oil from 36°C to 21°C.

  10. Isolation by distance, web service

    PubMed Central

    Jensen, Jeffrey L; Bohonak, Andrew J; Kelley, Scott T

    2005-01-01

    Background The population genetic pattern known as "isolation by distance" results from spatially limited gene flow and is a commonly observed phenomenon in natural populations. However, few software programs exist for estimating the degree of isolation by distance among populations, and they tend not to be user-friendly. Results We have created Isolation by Distance Web Service (IBDWS) a user-friendly web interface for determining patterns of isolation by distance. Using this site, population geneticists can perform a variety of powerful statistical tests including Mantel tests, Reduced Major Axis (RMA) regression analysis, as well as calculate FST between all pairs of populations and perform basic summary statistics (e.g., heterozygosity). All statistical results, including publication-quality scatter plots in Postscript format, are returned rapidly to the user and can be easily downloaded. Conclusion IBDWS population genetics analysis software is hosted at and documentation is available at . The source code has been made available on Source Forge at . PMID:15760479

  11. Advances on Genome Duplication Distances

    NASA Astrophysics Data System (ADS)

    Gagnon, Yves; Savard, Olivier Tremblay; Bertrand, Denis; El-Mabrouk, Nadia

    Given a phylogenetic tree involving Whole Genome Duplication events, we contribute to the problem of computing the rearrangement distance on a branch of a tree linking a duplication node d to a speciation node or a leaf s. In the case of a genome G at s containing exactly two copies of each gene, the genome halving problem is to find a perfectly duplicated genome D at d minimizing the rearrangement distance with G. We generalize the existing exact linear-time algorithm for genome halving to the case of a genome G with missing gene copies. In the case of a known ancestral duplicated genome D, we develop a greedy approach for computing the distance between G and D that is shown time-efficient and very accurate for both the rearrangement and DCJ distances.

  12. 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.

  13. 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

  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. 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…

  16. Distance education: turf and technology.

    PubMed

    Pickard, M R

    1992-07-01

    Distance learning fits with the mission and strategic plan of the University of Texas at Arlington. We believe these educational opportunities in nursing are highly desirable. The Board of Nurse Examiners for the State of Texas has approved this project and the Texas Higher Education Coordinating Board has approved it as a pilot project. The school will continue evaluation and creative problem-solving in the use of distance education.

  17. Etherington's Distance Duality with Birefringence

    NASA Astrophysics Data System (ADS)

    Schuller, Frederic; Werner, Marcus

    2017-07-01

    We consider light propagation in a spacetime whose kinematics allow weak birefringence, and whose dynamics have recently been derived by gravitational closure. Revisiting the definitions of luminosity and angular diameter distances in this setting, we present a modification of the Etherington distance duality relation in a weak gravitational field around a point mass. This provides the first concrete example of how the non-metricities implied by gravitational closure of birefringent electrodynamics affect observationally testable relations.

  18. Nominal Ocular Dazzle Distance (NODD)

    DTIC Science & Technology

    2015-02-23

    release; distribution unlimited. PA Case No: TSRL-PA-14-0076. Date cleared: Aug. 20 , 2014 13. SUPPLEMENTARY NOTES 14. Abstract A simple model...and Nominal Ocular Dazzle Distance (NODD). A validated intraocular scatter model has been combined with a contrast threshold target detection model to...target can be detected , and the NODD, the minimum distance for the visual detection of a target in the presence of laser dazzle. The model is suitable

  19. Lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse

    PubMed Central

    Kahan, Meldon; Wilson, Lynn; Mailis-Gagnon, Angela; Srivastava, Anita

    2011-01-01

    Résumé Objectif Présenter aux médecins de famille un résumé clinique pratique sur la prescription d’opioïdes à des populations particulières en se fondant sur les recommandations faites dans les lignes directrices canadiennes sur l’utilisation sécuritaire et efficace des opioïdes pour la douleur chronique non cancéreuse. Qualité des données Pour produire les lignes directrices, les chercheurs ont effectué une synthèse critique de la littérature médicale en insistant plus précisément sur les études de l’efficacité et de la sécurité des opioïdes dans des populations particulières. Message principal Les médecins de famille peuvent atténuer les risques de surdose, de sédation, d’usage abusif et de dépendance grâce à des stratégies adaptées à l’âge et à l’état de santé des patients. Dans le cas de patients à risque de dépendance, on devrait réserver les opioïdes aux douleurs nociceptives ou neuropathiques bien définies qui n’ont pas répondu aux traitements de première intention. Il faut procéder lentement au titrage des opioïdes, avec des dispensations fréquentes et une étroite surveillance pour dépister tout signe d’usage abusif. Une dépendance aux opioïdes suspectée est prise en charge au moyen d’une thérapie structurée aux opioïdes, d’un traitement à la méthadone ou à la buprénorphine ou encore d’un traitement fondé sur l’abstinence. Les patients souffrant de troubles de l’humeur ou d’anxiété ont tendance à avoir une réponse analgésique atténuée aux opioïdes, sont à risque plus élevé d’usage abusif et prennent souvent des sédatifs qui interagissent défavorablement avec les opioïdes. Il faut prendre des précautions semblables à celles utilisées avec d’autres patients à risque élevé. Il faut faire un sevrage progressif si la douleur du patient demeure sévère même avec un essai adéquat de thérapie aux opioïdes. Chez les personnes âgées, la s

  20. 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

  1. Categorical perception of tactile distance.

    PubMed

    Knight, Frances Le Cornu; Longo, Matthew R; Bremner, Andrew J

    2014-05-01

    The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased in acuity surrounding anatomical landmarks (in which stimuli near the wrist are perceptually elongated). We tested these two interpretations across two experiments, by comparing a well-documented bias to perceive mediolateral tactile distances across the forearm/hand as larger than proximodistal ones along the forearm/hand at three different sites (hand, wrist, and forearm). According to the 'categorical' interpretation, tactile distances should be elongated selectively in the proximodistal axis thus reducing the anisotropy. According to the 'localised acuity' interpretation, distances will be perceptually elongated in the vicinity of the wrist regardless of orientation, leading to increased overall size without affecting anisotropy. Consistent with the categorical account, we found a reduction in the magnitude of anisotropy at the wrist, with no evidence of a corresponding localised increase in precision. These findings demonstrate that we reference touch to a representation of the body that is categorically segmented into discrete parts, which consequently influences the perception of tactile distance.

  2. A normalized Levenshtein distance metric.

    PubMed

    Yujian, Li; Bo, Liu

    2007-06-01

    Although a number of normalized edit distances presented so far may offer good performance in some applications, none of them can be regarded as a genuine metric between strings because they do not satisfy the triangle inequality. Given two strings X and Y over a finite alphabet, this paper defines a new normalized edit distance between X and Y as a simple function of their lengths (|X| and |Y|) and the Generalized Levenshtein Distance (GLD) between them. The new distance can be easily computed through GLD with a complexity of O(|X|.|Y|) and it is a metric valued in [0, 1] under the condition that the weight function is a metric over the set of elementary edit operations with all costs of insertions/deletions having the same weight. Experiments using the AESA algorithm in handwritten digit recognition show that the new distance can generally provide similar results to some other normalized edit distances and may perform slightly better if the triangle inequality is violated in a particular data set.

  3. Quelle source pour la lithographie dans l'EUV ?

    NASA Astrophysics Data System (ADS)

    Ceccotti, T.

    2005-06-01

    L'impressionnante évolution des performances des circuits intégrés (CI) ces trente dernières années, répond à la désormais célèbre loi de Moore. Selon la prédiction faite en 1975 par le co-fondateur d'Intel Gordon Moore et qui n'a jamais été contredite, le nombre de transistors dans un CI allait doubler tous les 18mois. De simple intuition, la loi de Moore est devenue un impératif à respecter pour l'industrie des CI et des semi-conducteurs en général. La continuité dans les années à venir d'une telle progression technologique permettrait à ce secteur économique de garder, voire augmenter, toute son importance actuelle. Augmenter le nombre des transistors dans les CI signifie principalement réduire leur taille caractéristique de gravure et par conséquent la longueur d'onde utilisée. Depuis 2000, la lithographie dans l'extrême ultraviolet (EUVL) à 13.5 nm est considérée comme la plus prometteuse parmi les technologies appelées à remplacer la lithographie actuelle qui utilise du rayonnement laser à 193 nm comme source de lumière. La réalisation d'une machine lithographique industrielle utilisant du rayonnement EUV nécessite la résolution de nombreux problèmes technologiques qui font, depuis des années, l'objet de plusieurs programmes de recherche dans le monde. Une attention toute particulière est portée à la source de rayonnement EUVcar ses caractéristiques, notamment de puissance et de propreté, vont décider du succès ou pas de l'EUVL. Le cahier des charges d'une source EUV, les différents approches pour y répondre ainsi que leurs limites seront présentés ainsi qu'un état de l'art des performances des sources actuelles.

  4. Ressources pour les personnes atteintes de démence

    PubMed Central

    Frank, Christopher; Feldman, Sid; Schulz, Mary

    2011-01-01

    Résumé Objectif Résumer les services offerts par la Société Alzheimer et discuter des autres sources de soutien et d’information à la disposition des personnes atteintes de démence. Sources de l’information On a fait une recension dans Ovid MEDLINE à l’aide des expressions dementia, Alzheimer disease, community health services utilization et caregiver stress. Message principal Il a été démontré qu’il est bénéfique aux patients et aux aidants si le diagnostic de la démence est posé tôt dans la maladie. Une consultation auprès de la Société Alzheimer peut aider dans la prise en charge non pharmacologique de la démence au moment du diagnostic et en tout temps durant l’évolution de la maladie. Parmi les services offerts, on peut mentionner des renseignements au sujet de la démence, le soutien aux aidants, la coordination des services communautaires et une grande diversité de ressources écrites à l’intention des patients et des aidants. Là où il est offert, le programme Premier lien peut aider avec l’orientation vers des services en minimisant la nécessité pour les patients ou les aidants de communiquer eux-mêmes avec les filiales locales de la Société. On discute aussi d’autres ressources, y compris les soins de répit et les approches technologiques pour prendre en charge l’errance. Conclusion La Société Alzheimer joue un rôle important dans la prise en charge de la démence et les médecins de famille devraient toujours envisager d’y référer leurs patients au moment du diagnostic, quelle que soit la gravité de l’état. Premier lien, quand il est accessible, peut faciliter le contact avec les services. Des ressources comme les soins de répit et les programmes de jour devraient toujours être considérés lorsqu’ils sont disponibles.

  5. Eprinomectin 'pour-on' and the shedding of Haemonchus contortus eggs in experimentally infected goats.

    PubMed

    Molina, J M; Ruiz, A; Hernández, B; González, J F; Martín, S; Hernández, Y I

    2008-11-01

    The effect of eprinomectin on goats experimentally infected with the nematode Haemonchus contortus was investigated. Faecal analysis showed that a single dose of eprinomectin 'pour-on' delayed the onset of shedding of eggs for 10 to 17 days.

  6. Comparative efficacy of pour-on eprinomectin and ivermectin against Sarcoptes scabiei in buffaloes.

    PubMed

    Nazir, T; Katoch, R; Yadav, Anish; Godara, R

    2016-06-01

    The efficacy of eprinomectin and ivermectin pour-on was evaluated against Sarcoptes scabiei in naturally infested buffaloes. Eighteen animals were allocated into three groups (A, B and C) of six animals each. Animals in group A were treated with eprinomectin (pour-on) @ 0.5 mg/kg; group B with ivermectin (pour-on) @ 0.2 mg/kg while group C served as untreated controls. Skin scrapings were examined on days 0, 7, 14, 21, 28 and 42 post-treatment (PT). Skin scrapings were found free for mites on day 21 PT, with marked clinical improvement in the lesions after day 28 of treatment. Untreated control group continued to show severe progressive lesions throughout the study period. No clinical side-effects of the tested drugs were observed after treatment. This preliminary report on the efficacy of eprinomectin (pour-on) against S. scabiei in buffaloes is encouraging and results could be of considerable importance.

  7. Heat transfer modelling of the saltstone pouring and curing process. Task Number: 93-016-0

    SciTech Connect

    Shadday, M.A. Jr.

    1993-11-01

    A byproduct of the in tank precipitation, ITP, process will be 25 million gallons of low-level salt solution. This salt solution will be mixed with cement and a flyash/slag mixture and solidified in surface vaults in the Z-area Saltstone Facility. The curing process of saltstone involves exothermic reactions, and there is a maximum temperature limit of 90{degree}C for the curing saltstone. If this temperature limit is exceeded, the physical properties of the saltstone can be degraded. A heat transfer model of the saltstone pouring and curing process has been developed that predicts transient temperature distributions in the curing saltstone. The purpose of this model is to predict peak temperatures as functions of the several independent variables in this process: pour temperature, the pour schedule, and seasonal variations in the ambient temperature. The peak temperature of the saltstone is very sensitive to the internal heat generation that accompanies the curing process. Most of the energy is released over a short period of several hours, and the balance is released slowly over a period of time that can be in excess of a month. This long term low level internal heat generation is difficult to measure in laboratory calorimetry tests, and it can significantly influence the peak temperature in the saltstone. Due to the low thermal conductivity of the saltstone, the central region of the poured saltstone will essentially heat up adiabatically. The time dependence of the internal heat generation rate was determined from an analysis of the 1991 pilot pour test. With a pour schedule of eight hours a day and five days a week in the summer, the model predicts that the saltstone will have a peak temperature of 98 C with a pour temperature of 45 C, and a peak temperature of 88 C with a pour temperature of 30 C. With a pour schedule of three days a week, the peak temperature will be 88{degree}C with a pour temperature of 45 C, and 80 C with a pour temperature of 30 C.

  8. Dimensional accuracy of 2 irreversible hydrocolloid alternative impression materials with immediate and delayed pouring.

    PubMed

    Nassar, Usama; Hussein, Bayan; Oko, Andrea; Carey, Jason P; Flores-Mir, Carlos

    2012-01-01

    To assess dimensional accuracy and stability of 2 irreversible hydrocolloid alternative impression materials with immediate and delayed pouring. Two alternative impression materials, AlgiNot FS and Position Penta Quick, were compared with a traditional irreversible hydrocolloid, Jeltrate Plus antimicrobial alginate. Impressions were made of a metal model with 4 cylinders of known dimensions, with pouring performed immediately or after 4 hours of storage. A digital micrometer was used to measure cylinder diameter on the model and the poured casts. Dimensional changes were analyzed according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 19 (2004 version) (α=0.05). There were significant differences among the 3 materials, between the 2 pour times and as a function of storage time (multivariate analysis of variance, p<0.001). One-way analysis of variance revealed no significant differences between the 2 alternative impression materials, but changes for these materials differed significantly from those for the traditional impression material for immediate (p<0.05) and 4-hour (p<0.001) pouring. Linear dimensional changes for the 2 substitute materials were within the limits of the ANSI/ADA specification. With immediate pouring, both alternative impression materials exhibited minimal dimensional changes, which were maintained or reduced with 4-hour pouring. For both pouring times, these changes were less than 0.5%. The minimal dimensional changes observed with these irreversible hydrocolloid alternative impression materials after 4 hours of storage may save chairside time and help to produce accurate results for procedures such as partial denture framework, surgical guides, and pediatric and orthodontic devices.

  9. Refinement of primary Si grains in Al-20%Si alloy slurry through serpentine channel pouring process

    NASA Astrophysics Data System (ADS)

    Zheng, Zhi-kai; Mao, Wei-min; Liu, Zhi-yong; Wang, Dong; Yue, Rui

    2016-05-01

    In this study, a serpentine channel pouring process was used to prepare the semi-solid Al-20%Si alloy slurry and refine primary Si grains in the alloy. The effects of the pouring temperature, number of curves in the serpentine channel, and material of the serpentine channel on the size of primary Si grains in the semi-solid Al-20%Si alloy slurry were investigated. The results showed that the pouring temperature, number of the curves, and material of the channel strongly affected the size and distribution of the primary Si grains. The pouring temperature exerted the strongest effect, followed by the number of the curves and then the material of the channel. Under experimental conditions of a four-curve copper channel and a pouring temperature of 701°C, primary Si grains in the semi-solid Al-20%Si alloy slurry were refined to the greatest extent, and the lath-like grains were changed into granular grains. Moreover, the equivalent grain diameter and the average shape coefficient of primary Si grains in the satisfactory semi-solid Al-20%Si alloy slurry were 24.4 μm and 0.89, respectively. Finally, the refinement mechanism and distribution rule of primary Si grains in the slurry prepared through the serpentine channel pouring process were analyzed and discussed.

  10. Solution saline hypertonique pour la bronchiolite chez les bébés

    PubMed Central

    Grewal, Simran; Goldman, Ran D.

    2015-01-01

    Résumé Question J’ai récemment reçu le rapport du congé de l’hôpital d’un patient de 1 an admis pour une bronchiolite. On y indiquait qu’il avait été traité, entre autres, avec une solution saline hypertonique inhalée. Cette thérapie est-elle recommandée pour les enfants en milieu de soins aigus? Réponse La bronchiolite, causée principalement par le virus respiratoire syncytial, est très commune en hiver. C’est la cause la plus fréquente d’hospitalisation durant l’enfance. Plusieurs bonnes études ont été effectuées au cours de la dernière décennie sur l’utilisation d’une solution saline hypertonique nébulisée pour la prise en charge de la bronchiolite; toutefois, leurs résultats sont conflictuels. Quoiqu’il puisse y avoir un rôle pour la solution saline hypertonique nébulisée chez les enfants hospitalisés pour une bronchiolite pendant plus de 3 jours, ce traitement dans d’autres milieux ne confère pas suffisamment de bienfaits pour recommander son utilisation.

  11. Accuracy of Multiple Pour Cast from Various Elastomer Impression Methods.

    PubMed

    Haralur, Satheesh B; Saad Toman, Majed; Ali Al-Shahrani, Abdullah; Ali Al-Qarni, Abdullah

    2016-01-01

    The accurate duplicate cast obtained from a single impression reduces the profession clinical time, patient inconvenience, and extra material cost. The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two sets of six each custom aluminum trays were fabricated, with five mm spacer and two mm spacer. The impression methods evaluated during the study were additional silicone putty reline (two steps), heavy-light body (one step), monophase (one step), and polyether (one step). Type IV gypsum casts were poured at the interval of one hour, 12 hours, 24 hours, and 48 hours. The resultant cast was measured with traveling microscope for the comparative dimensional accuracy. The data obtained were subjected to Analysis of Variance test at significance level <0.05. The die obtained from two-step putty reline impression techniques had the percentage of variation for the height -0.36 to -0.97%, while diameter was increased by 0.40-0.90%. The values for one-step heavy-light body impression dies, additional silicone monophase impressions, and polyether were -0.73 to -1.21%, -1.34%, and -1.46% for the height and 0.50-0.80%, 1.20%, and -1.30% for the width, respectively.

  12. Device for controlling the pouring of molten materials

    DOEpatents

    Moore, Alan F.; Duncan, Alfred L.

    1994-01-01

    A device for controlling the pouring of a molten material from a crucible or other container. The device (10) includes an annular retainer ring (12) for mounting in the drain opening in the bottom of a conventional crucible (16), the retainer ring defining a opening (14) therethrough. The device (10) also includes a plug member (22) having an annular forward end portion (24) for force-fit reception in the opening (14) of the retainer ring (12) to selectively seal the opening (14) and for being selectively forced through the opening (14). The plug member (22) has a rear end portion (26) for being positioned within the crucible (16), the rear end portion (26) including stop means for prohibiting the rear end portion from passing through the opening (14) in the retainer ring (12) when the forward end portion (24) is selectively forced through the opening. The plug member (22) defines at least one, and preferably a plurality of flutes (32), each extending from a point rearward the annular forward end portion (24) of the plug member (22), and forward the stop means, to a point rearward of the stop means. The flutes (32) permit fluid communication between the interior and exterior of the crucible (16) when the forward end portion (24) of the plug member (22) is forced through the opening (14) in the retaining ring (12) such that the molten material is allowed to flow from the crucible (16).

  13. Device for controlling the pouring of molten materials

    DOEpatents

    Moore, A.F.; Duncan, A.L.

    1994-02-15

    A device is described for controlling the pouring of a molten material from a crucible or other container. The device includes an annular retainer ring for mounting in the drain opening in the bottom of a conventional crucible, the retainer ring defining a opening there through. The device also includes a plug member having an annular forward end portion for force-fit reception in the opening of the retainer ring to selectively seal the opening and for being selectively forced through the opening. The plug member has a rear end portion for being positioned within the crucible, the rear end portion including stop means for prohibiting the rear end portion from passing through the opening in the retainer ring when the forward end portion is selectively forced through the opening. The plug member defines at least one, and preferably a plurality of flutes, each extending from a point rearward the annular forward end portion of the plug member, and forward the stop means, to a point rearward of the stop means. The flutes permit fluid communication between the interior and exterior of the crucible when the forward end portion of the plug member is forced through the opening in the retaining ring such that the molten material is allowed to flow from the crucible. 5 figures.

  14. Accuracy of Multiple Pour Cast from Various Elastomer Impression Methods

    PubMed Central

    Saad Toman, Majed; Ali Al-Shahrani, Abdullah; Ali Al-Qarni, Abdullah

    2016-01-01

    The accurate duplicate cast obtained from a single impression reduces the profession clinical time, patient inconvenience, and extra material cost. The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two sets of six each custom aluminum trays were fabricated, with five mm spacer and two mm spacer. The impression methods evaluated during the study were additional silicone putty reline (two steps), heavy-light body (one step), monophase (one step), and polyether (one step). Type IV gypsum casts were poured at the interval of one hour, 12 hours, 24 hours, and 48 hours. The resultant cast was measured with traveling microscope for the comparative dimensional accuracy. The data obtained were subjected to Analysis of Variance test at significance level <0.05. The die obtained from two-step putty reline impression techniques had the percentage of variation for the height −0.36 to −0.97%, while diameter was increased by 0.40–0.90%. The values for one-step heavy-light body impression dies, additional silicone monophase impressions, and polyether were −0.73 to −1.21%, −1.34%, and −1.46% for the height and 0.50–0.80%, 1.20%, and −1.30% for the width, respectively. PMID:28096815

  15. 14 CFR 23.75 - Landing distance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Landing distance. 23.75 Section 23.75... distance. The horizontal distance necessary to land and come to a complete stop from a point 50 feet above... distance would be increased when a landing is made with that engine inoperative, the landing distance must...

  16. 14 CFR 23.75 - Landing distance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing distance. 23.75 Section 23.75... distance. The horizontal distance necessary to land and come to a complete stop from a point 50 feet above... distance would be increased when a landing is made with that engine inoperative, the landing distance must...

  17. 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.

  18. The unassigned distance geometry problem

    DOE PAGES

    Duxbury, P. M.; Granlund, L.; Gujarathi, S. R.; ...

    2015-11-19

    Studies of distance geometry problems (DGP) have focused on cases where the vertices at the ends of all or most of the given distances are known or assigned, which we call assigned distance geometry problems (aDGPs). In this contribution we consider the unassigned distance geometry problem (uDGP) where the vertices associated with a given distance are unknown, so the graph structure has to be discovered. uDGPs arises when attempting to find the atomic structure of molecules and nanoparticles using X-ray or neutron diffraction data from non-crystalline materials. Rigidity theory provides a useful foundation for both aDGPs and uDGPs, though itmore » is restricted to generic realizations of graphs, and key results are summarized. Conditions for unique realization are discussed for aDGP and uDGP cases, build-up algorithms for both cases are described and experimental results for uDGP are presented.« less

  19. Individual differences in distance perception

    PubMed Central

    Jackson, Russell E.

    2009-01-01

    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. PMID:19324829

  20. Individual differences in distance perception.

    PubMed

    Jackson, Russell E

    2009-05-07

    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.

  1. DEER Distance Measurements on Proteins

    NASA Astrophysics Data System (ADS)

    Jeschke, Gunnar

    2012-05-01

    Distance distributions between paramagnetic centers in the range of 1.8 to 6 nm in membrane proteins and up to 10 nm in deuterated soluble proteins can be measured by the DEER technique. The number of paramagnetic centers and their relative orientation can be characterized. DEER does not require crystallization and is not limited with respect to the size of the protein or protein complex. Diamagnetic proteins are accessible by site-directed spin labeling. To characterize structure or structural changes, experimental protocols were optimized and techniques for artifact suppression were introduced. Data analysis programs were developed, and it was realized that interpretation of the distance distributions must take into account the conformational distribution of spin labels. First methods have appeared for deriving structural models from a small number of distance constraints. The present scope and limitations of the technique are illustrated.

  2. Solving the molecular distance geometry problem with inaccurate distance data

    PubMed Central

    2013-01-01

    We present a new iterative algorithm for the molecular distance geometry problem with inaccurate and sparse data, which is based on the solution of linear systems, maximum cliques, and a minimization of nonlinear least-squares function. Computational results with real protein structures are presented in order to validate our approach. PMID:23901894

  3. Solving the molecular distance geometry problem with inaccurate distance data.

    PubMed

    Souza, Michael; Lavor, Carlile; Muritiba, Albert; Maculan, Nelson

    2013-01-01

    We present a new iterative algorithm for the molecular distance geometry problem with inaccurate and sparse data, which is based on the solution of linear systems, maximum cliques, and a minimization of nonlinear least-squares function. Computational results with real protein structures are presented in order to validate our approach.

  4. 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…

  5. 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…

  6. 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

  7. 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.

  8. Gametic disequilibrium and physical distance

    SciTech Connect

    Zapata, C.; Visedo, G.

    1995-07-01

    The relationship between gametic disequilibrium and physical distance between RFLPs at different gene regions is of great interest due to the current research in fine gene mapping. A recent review found that gametic disequilibrium nearly always correlates significantly with physical distance in genomic regions greater than 50 to 60 kb in size, but it does not do so in smaller genomic regions. This conclusion is based on an analysis which is inappropriate as the r disequilibrium coefficient is frequency dependent, which disqualifies it from comparing disequilibrium between pairs of loci with different allelic frequencies. 11 refs., 2 tabs.

  9. 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.

  10. Ethics in Distance Education: Developing Ethical Policies.

    ERIC Educational Resources Information Center

    Gearhart, Deb

    2001-01-01

    Examines the changing world of education through distance education and discusses the need for ethics in distance education. Explains how to ethically develop policy for distance education, including Internet ethics, good practices guidelines, and involving faculty. (LRW)

  11. 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…

  12. 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…

  13. 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…

  14. Long-distance free fall

    NASA Astrophysics Data System (ADS)

    Gallant, Joseph; Carlson, James

    1999-03-01

    We present an analysis of a situation described in Milton's epic poem "Paradise Lost" in which we calculate the distance required for a nine-day free-fall from rest to the Earth. The resulting method is completely general, and can be applied to free-fall toward other bodies and to near-Earth free-fall as well.

  15. 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…

  16. 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…

  17. 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,…

  18. Designing a Distance Learning Facility.

    ERIC Educational Resources Information Center

    Lambert, Michael P.

    1998-01-01

    Details the design of a distance-learning facility through analysis of its functions, paper-handling requirements, and current and future communications-technology needs. It also lists special features the facility should have, including up-to-date wiring capacities for telecommunications, uplink and downlink capabilities to satellites, and…

  19. Distance Education for Technology Teachers

    ERIC Educational Resources Information Center

    Williams, P. John

    2004-01-01

    A typical definition of distance education is the delivery of instruction in a format that separates the teacher and learner, often both in time and space. It tends to be an umbrella term that may encompass more specific forms of education such as distributed learning, independent study, correspondence education, satellite education, etc. This…

  20. Quality Connection: Going the Distance

    ERIC Educational Resources Information Center

    Jenney, Timothy R.; Roupas, Eva K.

    2003-01-01

    In 1999, Virginia Beach City Public Schools launched a completely new distance learning (DL) initiative, Quality Connection. Since that time, through perseverance and creative thinking, the program has become a model of technology as well as a highly successful method of delivering services to a wide variety of stakeholders. Not only do students…

  1. Distance Education Clearinghouse Web Site.

    ERIC Educational Resources Information Center

    Adams, Kate; Martin, Sara

    A World Wide Web site, developed by University of Nebraska-Lincoln Information Services staff and funded by a NEB*SAT (Nebraska's multiple channel satellite and optical fiber educational telecommunications network) grant, provides a clearinghouse of distance education, Internet, and Web page development information that is useful to librarians and…

  2. Video surveillance using distance maps

    NASA Astrophysics Data System (ADS)

    Schouten, Theo E.; Kuppens, Harco C.; van den Broek, Egon L.

    2006-02-01

    Human vigilance is limited; hence, automatic motion and distance detection is one of the central issues in video surveillance. Hereby, many aspects are of importance, this paper specially addresses: efficiency, achieving real-time performance, accuracy, and robustness against various noise factors. To obtain fully controlled test environments, an artificial development center for robot navigation is introduced in which several parameters can be set (e.g., number of objects, trajectories and type and amount of noise). In the videos, for each following frame, movement of stationary objects is detected and pixels of moving objects are located from which moving objects are identified in a robust way. An Exact Euclidean Distance Map (E2DM) is utilized to determine accurately the distances between moving and stationary objects. Together with the determined distances between moving objects and the detected movement of stationary objects, this provides the input for detecting unwanted situations in the scene. Further, each intelligent object (e.g., a robot), is provided with its E2DM, allowing the object to plan its course of action. Timing results are specified for each program block of the processing chain for 20 different setups. So, the current paper presents extensive, experimentally controlled research on real-time, accurate, and robust motion detection for video surveillance, using E2DMs, which makes it a unique approach.

  3. Delineating Personal Distance and Territoriality

    ERIC Educational Resources Information Center

    Becker, Franklin D.; Mayo, Clara

    1971-01-01

    Two concepts describing human special behavior are delineated. A field experiment was designed to test whether personal belongings left as markers in public areas (i.e. cafeteria setting) function to protect a territory or to maintain a comfortable social distance. It is suggested the term territory" be restricted to situations in which the space…

  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. 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…

  6. Communication Barriers in Distance Education

    ERIC Educational Resources Information Center

    Isman, Aytekin; Dabaj, Fahme; Altinay, Fahriye; Altinay, Zehra

    2003-01-01

    Communication is a key concept as being the major tool for people in order to satisfy their needs. It is an activity which refers as process and effective communication requires qualified communication with the elimination of communication barriers. As it is known, distance education is a new trend by following contemporary facilities and tools…

  7. 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)

  8. Ethical Considerations in Distance Education.

    ERIC Educational Resources Information Center

    Reed, Diane; Sork, Thomas J.

    1990-01-01

    Discusses issues in distance education for adults that can affect the welfare of others and suggests ethical sensitivity is needed. Ethical issues addressed include admission and retention of students; course development and presentation; program and course marketing; administrative issues; learner/instructor interaction; and evaluation. (29…

  9. Quality Assurance in Distance Education.

    ERIC Educational Resources Information Center

    Zuniga, Etter; Krauth, Barbara

    1996-01-01

    This publication is one of a series designed as a companion to the Western Interstate Commission for Higher Education (WICHE)'s fact book, "Policy Indicators for Higher Education: WICHE States." The title article maintains that the growth of distance learning programs has heightened existing concerns about their quality. Institutions can…

  10. Next Generation Distance Education Systems.

    ERIC Educational Resources Information Center

    Saba, Farhad, Ed.

    2000-01-01

    Discusses next generation distance education systems, which include research in cognitive science, systems science, and communication theory to provide a learning environment with student autonomy congruent to prior learning, learning objectives, and content materials to be mastered. Describes Advanced Distributed Learning (ADL), object…

  11. Student Preparedness for Distance Education.

    ERIC Educational Resources Information Center

    Mattice, Nancy J.; Dixon, Phillip Scott

    This paper presents the results of a student survey on computer-mediated distance education (DE) at the College of the Canyons. The survey queried students about whether DE fit their lifestyle, previous DE courses, access to a computer, the Internet and e-mail, and whether they would enroll in an on-line course. A total of 906 surveys were…

  12. 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)

  13. Designing a Distance Learning Facility.

    ERIC Educational Resources Information Center

    Lambert, Michael P.

    1998-01-01

    Details the design of a distance-learning facility through analysis of its functions, paper-handling requirements, and current and future communications-technology needs. It also lists special features the facility should have, including up-to-date wiring capacities for telecommunications, uplink and downlink capabilities to satellites, and…

  14. The Future of Distance Education.

    ERIC Educational Resources Information Center

    Saba, Farhad

    2000-01-01

    Examines factors that will influence how distance education is practiced in the first few decades of this new century. Discusses developments in digital technology; the exponential growth of knowledge about the brain, as well as physiology, chemistry, and psychology of learning; the system relationship between individual learners and instructors;…

  15. 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)

  16. 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.

  17. 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…

  18. Innovations en vaccinologie: enjeux et perspectives pour l’Afrique

    PubMed Central

    Diop, Doudou; Sanicas, Melvin

    2017-01-01

    La vaccination est incontestablement l’une des interventions de santé publique les plus efficaces et les plus rentables qui soient. Les vaccins continuent de révolutionner notre capacité à prévenir les maladies et à améliorer la santé. Avec toutes les avancées technologiques, nous sommes en mesure d’étendre les avantages des vaccins à plus de gens et de fournir une meilleure protection contre les maladies infectieuses mortelles. Toutefois, avec le développement incessant de nouvelles souches microbiennes à travers le monde, la recherche en vaccinologie se doit d’innover continuellement. D’énormes progrès ont été réalisés pour améliorer la couverture vaccinale et introduire de nouveaux vaccins en Afrique. De nouveaux types de vaccins associés à des outils de vectorisation, d’administration et de délivrance spécifiques mais aussi des adjuvants susceptibles de moduler finement la réponse immunitaire sont attendus dans le futur. En Afrique, il est nécessaire de développer une approche régionale afin de répondre efficacement aux nombreux défis. Une meilleure information, la formation des personnels de santé en vaccinologie et des recherches bien ciblées sont les clés des futurs accomplissements dans le domaine. PMID:28690749

  19. Matériaux pour la combustion catalytique

    NASA Astrophysics Data System (ADS)

    Lunot, C.

    2002-04-01

    La combustion catalytique est l'une des technologies les plus prometteuses pour réaliser une combustion ultra-propre des hydrocarbures et notamment du gaz naturel. Aujourd'hui, cependant, les produits commerciaux utilisant cette technologie sont peu nombreux et le plus souvent réservés à des applications basse température (500-700°C) à cause de la limitation liée à la durée de vie des catalyseurs utilisés (métaux précieux). Le développement de cette technologie est donc intimement lié à des défis “matériaux”, et notamment à l'obtention de catalyseurs actifs et durables au moins plusieurs milliers d'heures à des températures comprises entre 700 et 1 100°C. Or les catalyseurs de type métaux précieux, très actifs y compris à basse température, ont une durée de vie (maintien de leur activité catalytique dans le temps) d'autant plus limitée que la température de l'application est élevée. A l'inverse, les catalyseurs de type pérovskite ou hexaaluminate, dont la durée de vie à haute température est satisfaisante, présentent une activité plus faible qui rend notamment l'amorçage de la combustion catalytique délicate. C'est pourquoi les solutions potentielles sont à rechercher non seulement du côté matériaux de catalyseurs mais aussi du côté ingénierie et conception des matériels associés.

  20. Modification et caractérisation de la surface de fibres de verre pour son insertion postérieure dans des matériaux cimentaires

    NASA Astrophysics Data System (ADS)

    Bismarck, A.; Ajuriagojeaskoa, E. E.; Springer, J.; Habel, W. R.

    1999-07-01

    Optical fibres are widely used as physical and mechanical sensors in various matrices. Those commercial available fibres are mostly coated with different polymers (e.g. polyimide). The problem of using such coatings is the undefined adhesion and the stress transmission from the matrix material into the fibre as well as the alkaline attack from the cementitious environments onto the glass surface. Therefore the known silanisation process with alkylsilanes for surface modification was studied. To achieve a silane film onto the fibre surface as close as possible a fibre pre-treatment in oxygen plasma was applied. The wetting behaviour of the oxygen plasma treated fibres as well as the silanized fibres were studied using the Wilhelmy-method. The influence of the silane concentration and the time of the pre-treatment on the wetting properties was investigated. By scanning electron microscopy, changes of the surface morphology were detected. Additionally, the mechanical properties of the oxygen plasma treated fibres, and silanized fibres exposed to a highly alkaline pore solution were measured. For selected fibre samples (decoated and untreated as well as silanized fibres) the adhesion to a concrete matrix was studied using the indention test. Les fibres optiques sont de plus en plus utilisées comme capteurs des propriétés physiques et mécaniques de nombreuses matrices. Ces fibres commerciales sont généralement enrobées avec différents polymères (par exemple polyimide). Les problèmes dus à l'enrobage des fibres optiques sont une adhésion et une transmission de charge de la matrice du béton à la fibre non définies. Un autre problème majeur est l'alcalinité du béton et son influence sur la surface de la fibre. Nous avons utilisé le procédé de silanisation. Pour obtenir un film de silane le plus homogène possible sur la surface, les fibres sont pré-traitées par le plasma d?oxygène. Le mouillage de fibres traitées par le plasma d?oxygène, ainsi que

  1. Modèle mathématique pour l'étude des équilibres physico-chimiques de permanentes.

    PubMed

    Chiodi, F

    1989-12-01

    Résumé La plupart des permanentes du commerce sont constituées d'acide thioglycolique (éventuellement associéà l'acide thiolactique), neutralisé par l'ammoniac, elles sont additionnées de carbonate d'ammonium comme tampon. Le système peut etre traité comme la neutralisation d'un mélange d'acides thioglycolique et carbonique par l'ammoniac, et il est complètement défini par trois paramètres, trois concentrations, ou deux concentrations et le pH, ou trois paramètres analytiques indépendants. Les calculs théoriques de l'équilibre sont compliqués du fait qu'il s'agit de l'équilibre de deux diacides faibles neutralisés par une base faible. Un modèle mathématique développé exclusivement par des équations théoriques permet l'interprétation des équilibres et la réalisation des calculs fiable pour la préparation des formules remplissant certaines caractéristiques. Le modèle permet de réaliser facilement des simulations en faisant varier les concentrations, les acides (par la voie des constantes de dissociation) ou d'associer différents acids et/ou bases organiques ou minérales. Une application complémentaire du modèle est de tracer la courbe dérivée à la courbe de neutralisation et de cette façon mesurer l'effet tampon en différents points par la mesure de sa pente. Synopsis Mathematical model for the study of physico-chemical equilibria in permanent wave solutions Most waving lotions on the market are prepared with thioglycolic acid (eventually associated with thiolactic acid) neutralized with ammonium hydroxide and buffered with ammonium bicarbonate. The system can be treated as the neutralization of a mix of carbonic acid and thioglycolic acid by ammonia and it is completely defined by three parameters: three concentrations; or two concentrations and pH; or three independent analytical parameters. Theoretical calculations of the equilibrium are difficult because the equilibrium involves at least two weak acids with a weak base

  2. The Semantic Distance Model of Relevance Assessment.

    ERIC Educational Resources Information Center

    Brooks, Terrence A.

    1998-01-01

    Presents the Semantic Distance Model (SDM) of Relevance Assessment, a cognitive model of the relationship between semantic distance and relevance assessment. Discusses premises of the model such as the subjective nature of information and the metaphor of semantic distance. Empirical results illustrate the effects of semantic distance and semantic…

  3. Effective Teaching in Distance Education. ERIC Digest.

    ERIC Educational Resources Information Center

    Mielke, Dan

    Distance education is an alternative method for delivering academic course work to students unable to attend traditional campus-based classes. This Digest presents information on the many forms of distance education and keys to successful teaching with distance education. Distance education is a method of education in which the learner is…

  4. Continuing Engineering Education through Distance Learning

    ERIC Educational Resources Information Center

    Baukal, C. E.

    2010-01-01

    The demand for distance continuing engineering education (CEE) is growing. This article describes the following with regard to CEE: the purpose; its importance, trends and unique challenges. Distance education can meet some of these challenges. Benefits and challenges of distance CEE are discussed along with the different types of distance CEE…

  5. The Semantic Distance Model of Relevance Assessment.

    ERIC Educational Resources Information Center

    Brooks, Terrence A.

    1998-01-01

    Presents the Semantic Distance Model (SDM) of Relevance Assessment, a cognitive model of the relationship between semantic distance and relevance assessment. Discusses premises of the model such as the subjective nature of information and the metaphor of semantic distance. Empirical results illustrate the effects of semantic distance and semantic…

  6. Lunar Slope and Distance Estimation

    NASA Astrophysics Data System (ADS)

    Young, Laurence R.; Liu, Andrew M.; Oravetz, Christopher T.

    2008-06-01

    When astronauts return to the moon, they will undertake frequent treks across unknown terrain for geological investigations. Lunar conditions which are expected to affect human terrain perception include: the lack of an atmosphere or haze, the regolith luminance properties, the absence of familiar objects, and reduced gravity. This project examines the perceptual errors in human judgment of slopes and distance on earth using lunar-like terrain. Slope estimation errors of five subjects were measured for five featureless hills in Hanksville, Utah using visual and haptic measurement methods. This experiment was replicated in Virtual Reality (VR) with 7 subjects using stereo photographs. Significant overestimations were found in both experiments. Future work will measure slope and distance judgments on the moon using photographs from Apollo missions. The findings may influence astronaut training and design of navigation aids.

  7. Distance probes of dark energy

    SciTech Connect

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; Allen, S. W.; Baltay, C.; Cahn, R. N.; D’Andrea, C. B.; Dalal, N.; Dawson, K. S.; Denney, K. D.; Eisenstein, D. J.; Finley, D. A.; Freedman, W. L.; Ho, S.; Holz, D. E.; Kasen, D.; Kent, S. M.; Kessler, R.; Kuhlmann, S.; Linder, E. V.; Martini, P.; Nugent, P. E.; Perlmutter, S.; Peterson, B. M.; Riess, A. G.; Rubin, D.; Sako, M.; Suntzeff, N. V.; Suzuki, N.; Thomas, R. C.; Wood-Vasey, W. M.; Woosley, S. E.

    2015-03-01

    This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  8. SISAM interferometer for distance measurements.

    PubMed

    Verrier, I; Brun, G; Goure, J P

    1997-09-01

    We measure short distances with a spectromètre interférentiel à sélection par l'amplitude de la modulation (SISAM) (interferential spectrometer by selection of amplitude modulation) interferometer that correlates optical fields. We present the method and the resolution of the system. A test with a Michelson interferometer shows SISAM's ability to detect phase change in one arm of the Michelson interferometer.

  9. Cosmological parallax-distance formula

    NASA Astrophysics Data System (ADS)

    Singal, Ashok K.

    2015-09-01

    The standard cosmological parallax-distance formula, as found in the literature, including text-books and reference books on cosmology, requires a correction. This correction stems from the fact that in the standard text-book derivation it has been ignored that any chosen baseline in a gravitationally bound system does not partake in the cosmological expansion. Though the correction is available in the literature for some time, the text-books still continue to use the older, incorrect formula, and its full implications are not yet fully realized. Apart from providing an alternate correct, closed-form expression that is more suitable and convenient for computations for certain limiting cases of FRW () world models, we also demonstrate how one can compute parallax distance for the currently favored flat-space accelerating-universe (, ) cosmologies. Further, we show that the correction in parallax distance at large redshifts could amount to a factor of three or even more. Moreover, even in an infinite universe the parallax distance does not increase indefinitely with redshift and that even the farthest possible observable point may have a finite parallax angle, a factor that needs to be carefully taken into account when using distant objects as the background field against which the parallax of a foreground object is to be measured. Some other complications that could arise in parallax measurements of a distant source, like that due to the deflection of incoming light by the gravitation field of the Sun and other planetary bodies in the solar system, are pointed out.

  10. Tuning the Cepheid distance scale

    NASA Astrophysics Data System (ADS)

    Mateo, Mario

    1992-09-01

    Ongoing observational programs (both from the ground and space) will provide a significantly larger sample of galaxies with well-studied Cepheids both within the Local Group and in more distant galaxies. Recent efforts in the calibration of the Cepheid distance scale utilizing Cepheids in star clusters in the Galaxy and in the Magellanic Clouds are described. Some of the significant advantages of utilizing LMC Cepheids in particular are emphasized, and the current status of the field is summarized.

  11. Tuning the Cepheid distance scale

    NASA Technical Reports Server (NTRS)

    Mateo, Mario

    1992-01-01

    Ongoing observational programs (both from the ground and space) will provide a significantly larger sample of galaxies with well-studied Cepheids both within the Local Group and in more distant galaxies. Recent efforts in the calibration of the Cepheid distance scale utilizing Cepheids in star clusters in the Galaxy and in the Magellanic Clouds are described. Some of the significant advantages of utilizing LMC Cepheids in particular are emphasized, and the current status of the field is summarized.

  12. Distance Probes of Dark Energy

    DOE PAGES

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; ...

    2015-03-15

    We present the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). This document summarizes the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  13. The Zero Exemplar Distance Problem

    NASA Astrophysics Data System (ADS)

    Jiang, Minghui

    Given two genomes with duplicate genes, Zero Exemplar Distance is the problem of deciding whether the two genomes can be reduced to the same genome without duplicate genes by deleting all but one copy of each gene in each genome. Blin, Fertin, Sikora, and Vialette recently proved that Zero Exemplar Distance for monochromosomal genomes is NP-hard even if each gene appears at most two times in each genome, thereby settling an important open question on genome rearrangement in the exemplar model. In this paper, we give a very simple alternative proof of this result. We also study the problem Zero Exemplar Distance for multichromosomal genomes without gene order: from one direction, we show that this problem is NP-hard even if each gene appears at most two times in each genome; from the other direction, we show that this problem admits a polynomial-time algorithm if only one of the two genomes has duplicate genes, and is fixed-parameter tractable if the parameter is the maximum number of chromosomes in each genome.

  14. Teaching Chemistry via Distance Education

    NASA Astrophysics Data System (ADS)

    Boschmann, Erwin

    2003-06-01

    This paper describes a chemistry course taught at Indiana University Purdue University, Indianapolis via television, with a Web version added later. The television format is a delivery technology; the Web is an engagement technology and is preferred since it requires student participation. The distance-laboratory component presented the greatest challenge since laboratories via distance education are not a part of the U.S. academic culture. Appropriate experiments have been developed with the consultation of experts from The Open University in the United Kingdom, Athabasca University in Canada, and Monash University in Australia. The criteria used in the development of experiments are: (1) they must be credible academic experiences equal to or better than those used on campus, (2) they must be easy to perform without supervision, (3) they must be safe, and (4) they must meet all legal requirements. An evaluation of the program using three different approaches is described. The paper concludes that technology-mediated distance education students do as well as on-campus students, but drop out at a higher rate. It is very important to communicate with students frequently, and technology tools ought to be used only if good pedagogy is enhanced by their use.

  15. Ghost imaging with broad distance

    NASA Astrophysics Data System (ADS)

    Duan, De-Yang; Zhang, Lu; Du, Shao-Jiang; Xia, Yun-Jie

    2015-10-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178012, 11204156, 11304179, and 11247240), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant Nos. 20133705110001 and 20123705120002), the Scientific Research Foundation for Outstanding Young Scientists of Shandong Province, China (Grant No. BS2013DX034), and the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ024).

  16. The Magnetotail at Lunar Distance

    NASA Astrophysics Data System (ADS)

    Sibeck, D. G.

    2015-12-01

    This presentation reviews some of the single-point observations of the magnetotail at lunar distances made by ALSEP, Explorer 33, 35, ISEE-3, and Geotail that form the framework for interpreting more recent dual-spacecraft ARTEMIS observations. Earth's distant magnetotail flaps, twists, and flattens in response to variations in the solar wind flow direction and interplanetary magnetic field (IMF) orientation. It may even disappear leaving nothing more than a wake during strongly northward IMF orientations. Standing slow mode expansion fans provide for a gradual transition between magnetotail lobe and magnetosheath plasma and magnetic field parameters. The distant neutral line may at times reside at lunar distances, creating jets of sunward-streaming plasma within the cislunar plasma sheet and layers of streaming energetic particles on its boundaries. Reconnection at near-Earth neutral lines releases antisunward-moving plasmoids that transit lunar distances, briefly expanding the diameter of the plasma sheet and magnetotail. Taken as a whole, the distant magnetotail is a fascinating plasma laboratory and a region of great important to the magnetosphere.

  17. Dispositifs semi-conducteurs pour biodetection photonique et imagerie hyperspectrale

    NASA Astrophysics Data System (ADS)

    Lepage, Dominic

    La creation d'un microsysteme d'analyse biochimique, capable de livrer des diagnostics preliminaires sur la quantification d'elements pathogenes, est un defi multidisciplinaire ayant un impact potentiel important sur la majorite des activites humaines en sante et securite. En effet, un dispositif integre, peu dispendieux et livrant des resultats facilement interpretables, permettrait une vulgarisation des capacites de biodetection a travers differents domaines d'applications societaires et industriels. Le present document se concentre sur l'integration monolithique d'une methode de biocaracterisation dans le but de generer un transducteur miniaturise et efficace, element central d'un microsysteme de detection. Le projet de recherche ici presente vise l'etude de l'applicabilite d'un capteur plasmonique integre par l'entremise de nanostructures semi-conductrices aux proprietes quantiques et luminescentes. L'approche presentee est globale; c'est-a-dire qu'on vise a repondre aux questions fondamentales impliquant la comprehension des phenomenes photoniques, le developpement et la fabrication des dispositifs, les methodes de caracterisations possibles ainsi que l'application d'un transducteur SPR integre a la biodetection. En d'autres termes : dans quelles circonstances et comment un transducteur plasmonique integre doit-il etre realise pour l'application a la detection delocalisee d'elements pathogenes? Dans le but d'engendrer un instrument simple a l'echelle de l'usager, l'integration de la connaissance a l'echelle du design est donc effectuee. Ainsi, des capteurs plasmoniques monolithiques sont concus a l'aide de modeles theoriques ici presentes. Un instrument de mesure hyperspectrale conjuguee permettant de cartographier directement la relation de dispersion des plasmons diffractes a ete construit et teste. Cet instrument est employe a la cartographie d'elements de diffusion. Finalement, une demonstration du fonctionnement du dispositif, appliquee a la

  18. Analyse experimentale des performances d'une batterie au lithium pour l'aeronautique

    NASA Astrophysics Data System (ADS)

    Bonnin, Romain

    Ce memoire a pour objectif d'identifier et d'etudier les performances necessaires pour qu'une batterie au lithium puisse etre utilisee dans le secteur de l'aeronautique. C'est pourquoi dans le cadre de notre recherche, nous allons proposer une procedure de tests permettant d'analyser et de determiner si la batterie au lithium peut etre implantee dans un avion. En vue de repondre a l'analyse des performances, une etude des fonctionnalites demandees par l'avion ainsi que des normes preexistantes vont etre effectuees. Suite a cette etape, nous allons elaborer un banc d'essais. Une fois le banc d'essais acheve, nous allons tester une batterie au lithium qui est supposee disposer de toutes les caracteristiques techniques requises pour etre implantee dans un avion. Ces tests nous permettront donc d'emettre un avis sur l'utilisation des batteries au lithium dans le domaine de l'aeronautique.

  19. Miroirs multicouches C/SI a incidence normale pour la region spectrale 25-40 nanometres

    NASA Astrophysics Data System (ADS)

    Grigonis, Marius

    Nous avons propose la nouvelle combinaison de materiaux, C/Si, pour la fabrication de miroirs multicouches a incidence normale dans la region spectrale 25-40 nm. Les resultats experimentaux montrent que cette combinaison possede une reflectivite d'environ ~25% dans la region spectrale 25-33 nm et une reflectivite d'environ ~23% dans la region spectrale 33-40 nm. Ces valeurs de reflectivite sont les plus grandes obtenues jusqu'a maintenant dans la region spectrale 25-40 nm. Les miroirs multicouches ont ete par la suite caracterises par microscopie electronique a transmission, par diverses techniques de diffraction des rayons X et par spectroscopies d'electrons AES et ESCA. La resistance des miroirs aux temperatures elevees a ete egalement etudiee. Les resultats fournis par les methodes de caracterisation indiquent que cette combinaison possede des caracteristiques tres prometteuses pour son application comme miroir pour les rayons X mous.

  20. Spectroscopie pompe-sonde pour la détection de bioaérosols

    NASA Astrophysics Data System (ADS)

    Guyon, L.; Courvoisier, F.; Wood, V.; Boutou, V.; Bartelt, A.; Roth, M.; Rabitz, H.; Wolf, J. P.

    2006-10-01

    La fluorescence du Tryptophane excité par une impulsion ultra-brève à 270 nm peut être diminuée d'un facteur deux par une seconde impulsion à 800 nm, à l'aide d'un dispositif pompe-sonde. Cette décroissance est aussi observée pour les bactéries vivantes, dont le Tryptophane est l'un des fluorophores, tandis qu'aucune décroissance n'est observée pour d'autres molécules organiques comme le naphtalène ou le gazole, malgré des spectres d'absorption et de fluorescence similaires. Cette différence remarquable est très prometteuse pour la distinction d'aérosols biologiques et organiques.

  1. Large drinks are no mistake: Glass size, but not shape, affects alcoholic beverage drink pours

    PubMed Central

    Kerr, William C.; Patterson, Deidre; Koenen, Mary Albert; Greenfield, Thomas K.

    2009-01-01

    Introduction and Aims Drink alcohol content has been shown to be variable and is an important determinant of alcohol intake. This study evaluates claims regarding the effects of glass size and glass shape on the amount of alcohol in on-premise drinks. Design and Methods Wine and spirits drinks were purchased and measured in 80 on-premise establishments in 10 Northern California Counties. Drink alcohol content was measured as the liquid volume of the drink multiplied by the percentage alcohol by volume of given brands or from analysis of mixed drink and wine samples. Results Larger glass size was associated with larger on-premise pours of straight shots and mixed drinks served in the relatively large pint glass and variable “other” glass type were found to contain more alcohol than drinks served in a short wide glass. No significant differences were found for other drink types. Drinks poured in short wide glasses were not found to contain more alcohol than drinks poured in tall thin glasses. Bars with mostly black patrons were found to serve spirits drinks with more alcohol than bars with other patron types. Discussion and Conclusions Glass shape does not affect actual drink pours in the US but glass size does in some cases. Drinkers should measure wine and spirits pours at home to achieve standard drink amounts and consumer education programs should foster awareness of the relatively high drink alcohol content of on-premise wine and mixed spirits drinks. More research is needed to evaluate potential differences in drink pours by patron race and ethnicity. PMID:19594789

  2. Le partenariat en recherche: un véhicule pour atteindre les plus hauts sommets.

    PubMed

    Gélinas, Isabelle

    2016-10-01

    Les partenariats en ergothérapie entre les praticiens et les chercheurs sont importants pour produire des connaissances pertinentes pour la pratique clinique et pour favoriser la pratique fondée sur les données probantes au sein de la profession. BUT: Dans ce discours Muriel Driver, l'auteure discute des raisons pour lesquelles nous devons favoriser la participation des praticiens à la recherche et elle examine les conditions essentielles à la réussite des partenariats de recherche en collaboration. QUESTIONS CLÉS: Les partenariats de collaboration peuvent réduire les obstacles empêchant les praticiens de participer à la recherche et permettre de veiller à ce que les initiatives de recherche soient plus pertinentes pour la pratique clinique. Les facteurs clés pour établir et maintenir des partenariats significatifs sont la présence de conditions préalables et favorables au partenariat en lien avec le contexte, de même que l'utilisation de principes directeurs axés sur la vision, les valeurs, la confiance, la communication, le partage du pouvoir et les interactions. CONSÉQUENCES: Plusieurs des facteurs identifiés comme étant favorables à la réussite d'un partenariat de collaboration correspondent aux rôles fondamentaux des ergothérapeutes et témoignent de nos valeurs professionnelles. La prise en compte de ces facteurs lors de l'établissement de collaborations de recherche permettrait d'accroître les probabilités de réussite. © CAOT 2016.

  3. ANALYSIS OF DWPF SLUDGE BATCH 7A (MACROBATCH 8) POUR STREAM SAMPLES

    SciTech Connect

    Johnson, F.

    2012-05-01

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 7a (SB7a), also referred to as Macrobatch 8 (MB8), in June 2011. SB7a is a blend of the heel of Tank 40 from Sludge Batch 6 (SB6) and the SB7a material that was transferred to Tank 40 from Tank 51. SB7a was processed using Frit 418. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP), which is governed by the DWPF Waste Compliance Plan, and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. Three pour stream glass samples and two Melter Feed Tank (MFT) slurry samples were collected while processing SB7a. These additional samples were taken during SB7a to understand the impact of antifoam and the melter bubblers on glass redox chemistry. The samples were transferred to the Savannah River National Laboratory (SRNL) where they were analyzed. The following conclusions were drawn from the analytical results provided in this report: (1) The sum of oxides for the official SB7a pour stream glass is within the Product Composition Control System (PCCS) limits (95-105 wt%). (2) The average calculated Waste Dilution Factor (WDF) for SB7a is 2.3. In general, the measured radionuclide content of the official SB7a pour stream glass is in good agreement with the calculated values from the Tank 40 dried sludge results from the SB7a Waste Acceptance Program Specification (WAPS) sample. (3) As in previous pour stream samples, ruthenium and rhodium inclusions were detected by Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS) in the official SB7a pour stream sample. (4) The Product Consistency Test (PCT) results indicate that the official SB7a pour stream glass meets the waste acceptance criteria for durability with a normalized boron release of 0.64 g/L, which is an order of magnitude less than the Environmental

  4. Analysis Of The Sludge Batch 7b (Macrobatch 9) DWPF Pour Stream Glass Sample

    SciTech Connect

    Johnson, F. C.; Crawford, C. L.; Pareizs, J. M.

    2013-11-18

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 7b (SB7b), also referred to as Macrobatch 9 (MB9), in January 2012. SB7b is a blend of the heel of Tank 40 from Sludge Batch 7a (SB7a) and the SB7b material that was transferred to Tank 40 from Tank 51. SB7b was processed using Frit 418. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP), which is governed by the DWPF Waste Form Compliance Plan, and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. Two pour stream glass samples were collected while processing SB7b. The samples were transferred to the Savannah River National Laboratory (SRNL) where one was analyzed and the other was archived. The following conclusions were drawn from the analytical results provided in this report: The sum of oxides for the official SB7b pour stream glass is within the Product Composition Control System (PCCS) limits (95-105 wt%); The average calculated Waste Dilution Factor (WDF) for SB7b is 2.3. In general, the measured radionuclide content of the official SB7b pour stream glass is in good agreement with the calculated values from the Tank 40 dried sludge results from the SB7b Waste Acceptance Program Specification (WAPS) sample; As in previous pour stream samples, ruthenium and rhodium inclusions were detected by Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS) in the SB7b pour stream sample; The Product Consistency Test (PCT) results indicate that the official SB7b pour stream glass meets the waste acceptance criteria for durability with a normalized boron release of 0.8 g/L, which is an order of magnitude less than the Environmental Assessment (EA) glass; The measured density of the SB7b pour stream glass was 2.70 g/cm{sup 3}; The Fe{sup 2+}/ΣFe ratio of the SB7b pour stream samples was 0.07.

  5. Eprinomectin pour-on (EPRINEX® Pour-on, Merial): efficacy against gastrointestinal and pulmonary nematodes and pharmacokinetics in sheep.

    PubMed

    Hamel, Dietmar; Bosco, Antonio; Rinaldi, Laura; Cringoli, Giuseppe; Kaulfuß, Karl-Heinz; Kellermann, Michael; Fischer, James; Wang, Hailun; Kley, Katrin; Mayr, Sandra; Rauh, Renate; Visser, Martin; Wiefel, Thea; Fankhauser, Becky; Rehbein, Steffen

    2017-05-30

    The anthelmintic efficacy of the 0.5% w/v topical formulation of eprinomectin (EPN), EPRINEX® Pour-on (Merial) when administered at 1 mg/kg body weight was evaluated in sheep in two dose confirmation laboratory studies and one multicenter field study. In addition, the pharmacokinetics of EPN when administered at that dosage to adult sheep was determined. In the two dose confirmation studies, which included 10 sheep each, sheep treated with topical EPN had significantly (p < 0.05) fewer of the following nematodes than the untreated sheep with overall reduction of nematode counts by >99%: adult Dictyocaulus filaria, Haemonchus contortus, Teladorsagia circumcincta(pinnata/trifurcata), Trichostrongylus axei, T. colubriformis, T. vitrinus, Cooperia curticei, Nematodirus battus, Strongyloides papillosus, Chabertia ovina and Oesophagostomum venulosum, and inhibited fourth-stage Teladorsagia larvae. A total of 196 sheep harboring naturally acquired gastrointestinal nematode infections were included in the field efficacy study at two sites each in Germany (48 Merino x Ile de France lambs, 52 adult Merino females) and in Italy (adult male and female Bagnolese, Lacaune, Lacaune x Bagnolese, Bagnolese x Sarda sheep; 48 animals per site). Animals were blocked on pre-treatment body weight and within each block, one animal was randomly assigned to the control (untreated) group and three animals were randomly assigned to be treated with topical EPN. Examination of feces 14 days after treatment demonstrated that, relative to the controls, topical EPN-treated sheep had significantly (p < 0.0001) lower strongylid egg counts. Reduction was ≥97% at each site and 98.6% across all sites. Pharmacokinetics of EPN following single treatment with topical EPN were determined in eight ~4.5 year old female Merino cross sheep based on the analysis of plasma samples which were collected from two hours to 21 days following treatment. The main pharmacokinetic parameters were: Cmax 6.20

  6. Is the Glass Half Full or Half Empty? How to Reverse the Effect of Glass Elongation on the Volume Poured

    PubMed Central

    Caljouw, Simone R.; van Wijck, Ruud

    2014-01-01

    To reduce the volume of drinks and the risk of overconsumption, health professionals recommend the use of tall skinny instead of short wide glasses. Yet the results of the present study contradict this health advice. Participants who generously filled up a glass with lemonade served 9% more in tall narrow compared with short wide glasses (p<0.05). In addition, when pouring a small amount (i.e., a shot), participants poured 3% more in a short wide than in a tall narrow glass (p<0.05). Elongation may bias the perceived volume that is poured but also the perceived volume of the free space in the glass. We hypothesised that shifting attention from the bottom to the brim of the glass when filling it close to capacity might reverse the glass elongation effect on the quantity poured. This hypothesis was tested, by investigating two pouring tasks that differed in the required focus of attention. When the instruction was to match a reference volume, participants poured more liquid in the short wide compared with the tall narrow glass (p<0.05). The effect of glass elongation on poured volume was the opposite when the instruction was to leave space in the glasses for the reference volume. It seems likely that task and individual factors affect the pourer's viewing strategy and thus may determine the direction of the glass elongation effect on the volume poured. PMID:25343252

  7. Effect of storage time of extended-pour and conventional alginate impressions on dimensional accuracy of casts.

    PubMed

    Rohanian, Ahmad; Ommati Shabestari, Ghasem; Zeighami, Somayeh; Samadi, Mohammad Javad; Shamshiri, Ahmad Reza

    2014-11-01

    Some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast. In this experimental in-vitro trial, a total of 90 alginate impressions were made from a Dentoform model using Hydrogum 5, Tropicalgin and Alginoplast alginates. The impressions were stored in a sealed plastic bag without a damp paper towel for 0, 24, 48, 72 and 120 hours and then poured with type III dental stone. Cross-arch (facial of 6 to facial of 6 on the opposite side) and antero-posterior (distal of right first molar to the ipsilateral central incisor) measurements were made with a digital caliper on the casts. Data were analyzed by two-way and one-way ANOVA and Tukey's post-hoc test (P<0.05). Alginate type and the pouring time significantly affected the dimensional stability of alginate impressions (both Ps<0.001). Pouring of Hydrogum 5 impressions can be delayed for up to 120 hours without significant dimensional changes. Alginoplast impressions may be poured after 72 hours, but Tropicalgin should be poured immediately and the storage time should not be more than 24 hours. Immediate pouring of alginate impressions provides the highest accuracy in reproducing the teeth and adjacent tissues; however, this study demonstrated that pouring may be delayed for up to five days using extended-pour (Hydrogum 5) alginates.

  8. Mattig's relation and dynamical distance indicators

    NASA Astrophysics Data System (ADS)

    Teerikorpi, P.; Baryshev, Yu. V.

    2016-03-01

    We discuss how the redshift (Mattig) method in the Friedmann cosmology relates to dynamical distance indicators based on Newton's gravity (Teerikorpi 2011). It belongs to the class of indicators where the relevant length inside the system is the distance itself (in this case the proper metric distance). As the Friedmann model has a Newtonian analogy, its use to infer distances has instructive similarities to classical dynamical distance indicators. In view of the theoretical exact linear distance-velocity law, we emphasize that it is conceptually correct to derive the cosmological distance via the route: redshift (primarily observed) -> space expansion velocity (not directly observed) -> metric distance (physical length in ``cm''). Important properties of the proper metric distance are summarized.

  9. Distance Measurement Solves Astrophysical Mysteries

    NASA Astrophysics Data System (ADS)

    2003-08-01

    Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of

  10. Variable Distance Angular Symbology Reader

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F., Jr. (Inventor); Corder, Eric L. (Inventor)

    2006-01-01

    A variable distance angular symbology, reader utilizes at least one light source to direct light through a beam splitter and onto a target. A target may be angled relative to the impinging light beam up to and maybe even greater than 45deg. A reflected beam from the target passes through the beam splitter and is preferably directed 90deg relative to the light source through a telecentric lens to a scanner which records an image of the target such as a direct part marking code.

  11. Minimum distance classification in remote sensing

    NASA Technical Reports Server (NTRS)

    Wacker, A. G.; Landgrebe, D. A.

    1972-01-01

    The utilization of minimum distance classification methods in remote sensing problems, such as crop species identification, is considered. Literature concerning both minimum distance classification problems and distance measures is reviewed. Experimental results are presented for several examples. The objective of these examples is to: (a) compare the sample classification accuracy of a minimum distance classifier, with the vector classification accuracy of a maximum likelihood classifier, and (b) compare the accuracy of a parametric minimum distance classifier with that of a nonparametric one. Results show the minimum distance classifier performance is 5% to 10% better than that of the maximum likelihood classifier. The nonparametric classifier is only slightly better than the parametric version.

  12. Cosmic distance duality and cosmic transparency

    SciTech Connect

    Nair, Remya; Jhingan, Sanjay; Jain, Deepak E-mail: sanjay.jhingan@gmail.com

    2012-12-01

    We compare distance measurements obtained from two distance indicators, Supernovae observations (standard candles) and Baryon acoustic oscillation data (standard rulers). The Union2 sample of supernovae with BAO data from SDSS, 6dFGS and the latest BOSS and WiggleZ surveys is used in search for deviations from the distance duality relation. We find that the supernovae are brighter than expected from BAO measurements. The luminosity distances tend to be smaller then expected from angular diameter distance estimates as also found in earlier works on distance duality, but the trend is not statistically significant. This further constrains the cosmic transparency.

  13. Comparison of Gaia and asteroseismic distances

    NASA Astrophysics Data System (ADS)

    Yıldız, M.; ćelik Orhan, Z.; Ã-rtel, S.; Roth, M.

    2017-09-01

    Asteroseismology provides fundamental properties (mass, radius and effective temperature) of solar-like oscillating stars using so-called scaling relations. These properties allow the computation of the asteroseismic distance of stars. We compare the asteroseismic distances with the recently released Gaia distances for 74 stars studied in Yıldız et al. There is a very good agreement between these two distances; for 64 of these stars, the difference is less than 10 per cent. However, a systematic difference is seen if we use the effective temperature obtained by spectroscopic methods; the Gaia distances are about 5 per cent greater than the asteroseismic distances.

  14. Lightweight Distance Bounding Protocol against Relay Attacks

    NASA Astrophysics Data System (ADS)

    Kim, Jin Seok; Cho, Kookrae; Yum, Dae Hyun; Hong, Sung Je; Lee, Pil Joong

    Traditional authentication protocols are based on cryptographic techniques to achieve identity verification. Distance bounding protocols are an enhanced type of authentication protocol built upon both signal traversal time measurement and cryptographic techniques to accomplish distance verification as well as identity verification. A distance bounding protocol is usually designed to defend against the relay attack and the distance fraud attack. As there are applications to which the distance fraud attack is not a serious threat, we propose a streamlined distance bounding protocol that focuses on the relay attack. The proposed protocol is more efficient than previous protocols and has a low false acceptance rate under the relay attack.

  15. EVALUATION OF THE IMPACT OF THIN POURS ON SALTSTONE PROPERTIES

    SciTech Connect

    Cozzi, A.; Langton, C.; Fox, K.

    2012-10-02

    The proposed Saltstone Disposal Unit 6 (SDU6) is a larger structure than the SDU4 cells and larger than the disposal units (SDU2, SDU3, and SDU5) currently in use or under construction. The additional capacity provided by SDU6 is desired to reduce life cycle costs and support site accelerated closure goals. The larger size of the planned SDU6 could result in saltstone being placed in thinner lifts as the unit is filled. This study was performed to determine whether thinner layers of saltstone negatively impact the performance of the waste form. A larger number of cold joints could potentially result in increased drying, salt deposition, and surface oxidation. A matrix of samples was prepared to simulate thin pours ranging from 0.5 to 6 inches thick. Each sample was cured for at least 28 days prior to further characterization. Leachability results showed that there is no obvious impact of the number of grout layers on the Leachability Index values for Na and NO{sub 3}. The concentrations of Cr, NO{sub 2}, and C{sub 2}O{sub 4} were below detection limits for all of the leachates. No attempt was made to evaluate the oxidation of these samples since no measureable Cr was leached, although this would appear to indicate that Cr in the samples remained reduced for cold joints with surfaces exposed for approximately four days. The results of hydraulic conductivity measurements showed that the number of cold joints in the samples did not have a significant impact on the measured values for the vertical lift orientation (i.e., when the flow path is perpendicular to the cold joints). For the horizontal lift orientation (i.e., when the flow path is parallel to the cold joints), the number of cold joints in the samples also did not appear to have a significant impact on hydraulic conductivity. The measured hydraulic conductivity was faster when the flow path was parallel to the cold joints as compared to when the flow path was perpendicular to the cold joints. Percolation

  16. Time-Distance Helioseismology (Invited)

    NASA Astrophysics Data System (ADS)

    Duvall, T. L.

    2010-12-01

    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 charactistic 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.

  17. Instructional design for distance learning

    NASA Astrophysics Data System (ADS)

    Bourdeau, Jacqueline; Bates, Anthony

    1996-12-01

    An intrinsic link exists between instructional design (ID) and distance learning (DL). Their inextricability in the real world raises specific problems of interest in the field of ID. In no other teaching/learning situation is ID so essential as in DL. The conditions of DL make it a necessity to have long-term instructional planning, cost analysis, curriculum and course development, instructional materials development and maintenance, delivery plans, and detailed evaluation rules. Without all of these components, DL simply could not happen. It took some time for this neccessity to be acknowledged, as can be seen in the history of DL. However, ID becomes even more critical as increasingly costly and complex means are used. Conditions of learning have special features in DL, such as the role of media, since the professor, teacher or instructor is replaced by media for either transmitting information or for organizing learning activities. In this paper, the term distance learning will be used to mean media-based, remote or asynchronous learning supported by an instructional system. This paper introduces general features of DL and examines essential aspects of ID for DL, with special emphasis on ID methodologies and on media selection.

  18. Quantitative Microbial Risk Assessment Tutorial: Pour Point Analysis of Land-applied Microbial Loadings and Comparison of Simulated and Gaging Station Results

    EPA Science Inventory

    This tutorial demonstrates a pour point analysis • Initiates execution of the SDMPB.• Navigates the SDMPB.• Chooses a pour point within a watershed, delineates the sub-area that contributes to that pour point, and collects data for it.• Considers land applicat...

  19. Quantitative Microbial Risk Assessment Tutorial: Pour Point Analysis of Land-applied Microbial Loadings and Comparison of Simulated and Gaging Station Results

    EPA Science Inventory

    This tutorial demonstrates a pour point analysis • Initiates execution of the SDMPB.• Navigates the SDMPB.• Chooses a pour point within a watershed, delineates the sub-area that contributes to that pour point, and collects data for it.• Considers land applicat...

  20. Open and Distance Learning Today. Routledge Studies in Distance Education Series.

    ERIC Educational Resources Information Center

    Lockwood, Fred, Ed.

    This book contains the following papers on open and distance learning today: "Preface" (Daniel); "Big Bang Theory in Distance Education" (Hawkridge); "Practical Agenda for Theorists of Distance Education" (Perraton); "Trends, Directions and Needs: A View from Developing Countries" (Koul); "American…

  1. Open and Distance Learning Today. Routledge Studies in Distance Education Series.

    ERIC Educational Resources Information Center

    Lockwood, Fred, Ed.

    This book contains the following papers on open and distance learning today: "Preface" (Daniel); "Big Bang Theory in Distance Education" (Hawkridge); "Practical Agenda for Theorists of Distance Education" (Perraton); "Trends, Directions and Needs: A View from Developing Countries" (Koul); "American…

  2. Toward an Internally Consistent Astronomical Distance Scale

    NASA Astrophysics Data System (ADS)

    de Grijs, Richard; Courbin, Frédéric; Martínez-Vázquez, Clara E.; Monelli, Matteo; Oguri, Masamune; Suyu, Sherry H.

    2017-08-01

    Accurate astronomical distance determination is crucial for all fields in astrophysics, from Galactic to cosmological scales. Despite, or perhaps because of, significant efforts to determine accurate distances, using a wide range of methods, tracers, and techniques, an internally consistent astronomical distance framework has not yet been established. We review current efforts to homogenize the Local Group's distance framework, with particular emphasis on the potential of RR Lyrae stars as distance indicators, and attempt to extend this in an internally consistent manner to cosmological distances. Calibration based on Type Ia supernovae and distance determinations based on gravitational lensing represent particularly promising approaches. We provide a positive outlook to improvements to the status quo expected from future surveys, missions, and facilities. Astronomical distance determination has clearly reached maturity and near-consistency.

  3. Climbing the Cosmic Distance Ladder Artist Concept

    NASA Image and Video Library

    2012-10-03

    Astronomers using NASA Spitzer Space Telescope have greatly improved the cosmic distance ladder used to measure the expansion rate of the universe, its size and age. This artist concept symbolically shows a series of stars that have known distances.

  4. Numerical simulation of multi-mini-pot pouring process of a 13-ton steel ingot

    NASA Astrophysics Data System (ADS)

    Li, Jun; Ge, Honghao; Wang, Bin; Wu, Menghuai; Li, Jianguo

    2015-06-01

    Heavy ingots up to several hundred tons for power plant forgings exhibit large scale grain size and morphology differences, which are harmful to the design of forging parameters, and severe macrosegregation, which could not be eliminated during the subsequent forging and heat treatment processing. To cast these ingots with more homogeneity, a multi-mini-pot (MMP) poring technique is proposed, in which liquid metal is poured by multi-mini-pot (MMP) with intermission between each pot and solidification occurs step by step. In this paper, we are focus on the prediction of macrosegregation in MMP pouring process. A three-phase model is employed to study the MMP pouring process for a 13-ton heavy ingot. The main features of this three-phases model in such a heavy ingot can be quantitatively modelled: growth of columnar dendrite trunks; nucleation, growth and sedimentation of equiaxed crystals; thermosolutal convection of the melt; solute transport by both convection and crystal sedimentation; and the columnar-to-equiaxed transition (CET). The results shown that the MMP pouring technique tend to decrease the macrosegregation significantly by compared with the conventional method.

  5. Prediction du transfert thermique parietal pour la chambre de combustion d'une turbine a gaz

    NASA Astrophysics Data System (ADS)

    Gosselin, Pierre

    Des travaux ont demontre que la temperature de paroi pouvait etre predite avec precision (+/-6 a 10%) pour une chambre de combustion a pleine-echelle. Pour les resultats obtenus d'une autre chambre, aussi identique mais de plus petit diametre, la prediction de temperature de paroi n'offrait pas la meme precision de calcul. Cette etude est limitee aux turbines aeronautiques. L'objectif a ete de reevaluer globalement la prediction de la temperature de paroi d'une chambre de combustion de type GHOST a la lumiere des resultats obtenus des programmes experimentaux, tout en prenant en consideration l'influence des differents types de carburants. Par l'analyse du grand nombre de donnees experimentales, des modifications furent apportees a la methode de prediction utilisee pour les chambres a pleine echelle afin de reduire l'erreur de prediction pour les echelles a 1:2 (basse pression), 1:3 (basse pression) et 1:3 (haute pression). Une modelisation de la chambre de combustion a ete effectuee. L'analyse numerique nous a demontree que le code FLUENT/UNS predisait tres bien l'ecoulement a froid a l'interieur de la chambre de combustion GHOST echelle 1:1. La prediction etait acceptable au niveau des profils de temperature a l'interieur de la chambre. Cependant, une lacune a ete observee au niveau du modele d'evaporation du code.

  6. [Reconstruction of a fire homicide after pouring denatured alcohol on the victim].

    PubMed

    Bohnert, Michael; Lehmann, Rainer; Simon, Karl-Heinz; Wehner, Frank

    2009-01-01

    A 48-year-old man died from extensive burns suffered especially on the upper part of the body during a dispute with his ex-wife, who had poured spirit or a spirit-water mixture over him. For initially unknown reasons, the man's clothing caught fire. Whereas the public prosecutor assumed that the woman had intentionally poured a larger amount of spirit over her ex-husband before setting fire to him, the defendant first claimed to have poured the rest of a water-spirit mixture left over from cleaning the windows over the man and that his clothing caught fire on lighting a cigarette. To clarify the course of events, fire tests with spirit in various dilutions were conducted, which showed that even with undiluted spirit a direct contact with the flame of at least 1 second is necessary to start a fire. There is no deflagration, if spirit is used as a fire accelerant. In the trial, the defendant made a confession and admitted to have poured a mixture of 75% spirit and 25% water over her ex-husband and set fire to his right sleeve with the intention to kill him.

  7. Evaluation of a Pour-Through Water Treatment Device for Use as Microbiological Purifier

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) Office of Research and Development has evaluated the performance of a Point-of-Use (POU) pour-through device designed for use in India, developing and emerging market (D&E) countries, and under emergency situations in the Un...

  8. Salicylate de bismuth pour la diarrhée chez l’enfant

    PubMed Central

    Goldman, Ran D.

    2013-01-01

    Résumé Question J’ai reçu récemment un patient de 5 ans à qui, lors d’un voyage en Amérique du Sud, un médecin de famille local a prescrit du sous-salicylate de bismuth pour une diarrhée. Est-ce une pratique que nous devrions encourager? Réponse La recherche réalisée dans les pays en développement a fait valoir que l’utilisation du sous-salicylate de bismuth était efficace pour raccourcir la durée de la diarrhée. En dépit de ces constatations, son efficacité limitée, des préoccupations à propos du fait qu’il pourrait potentiellement causer le syndrome de Reye, les problèmes d’observance et son coût sont les principales raisons pour lesquelles on ne le recommande pas systématiquement pour les enfants.

  9. Matériaux pour la production d'hydrogène

    NASA Astrophysics Data System (ADS)

    Saint-Just, J.

    2002-04-01

    L'émergence des piles à combustible et l'apparition de l'hydrogène comme carburant dans des véhicules grand public comme les autobus, suscitent un élan fort pour la mise au point de technologies nouvelles pour la production d'hydrogène décentralisée et à petite échelle. Du fait de sa richesse en hydrogène. des réserves disponibles et de son infrastructure de distribution, le gaz naturel est considéré comme la ressource majeure pouvant fournir les quantités d'hydrogène nécessaires pour un passage progressif vers une économie de l'hydrogène dans les décennies immédiates en attendant que progressivement les énergies renouvelables prennent le relais. Des solutions innovantes, incluant de nouveaux matériaux, sont nécessaires pour la mise au point des petits générateurs d'hydrogène efficaces et bon marché alimenté au gaz naturel qui sont attendus par les fabricants (le piles à combustible, les acteurs de l'énergie et les fabricants de véhicules.

  10. Evaluation of a Pour-Through Water Treatment Device for Use as Microbiological Purifier

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) Office of Research and Development has evaluated the performance of a Point-of-Use (POU) pour-through device designed for use in India, developing and emerging market (D&E) countries, and under emergency situations in the Un...

  11. Coprological evaluation of pour-on and injectable formulation of moxidectin in beef cattle

    USDA-ARS?s Scientific Manuscript database

    Two, 28 day(d) studies were conducted with naturally infected beef calves to assess the effect of allo-grooming behavior on fecal egg count (FEG)reductions and coproculture counts following treatment with pour-on or injectable moxidectin. The first study was conducted at the USDA Southern Plains Ex...

  12. Sleeping distance in wild wolf packs

    USGS Publications Warehouse

    Knick, S.T.; Mech, L.D.

    1980-01-01

    Sleeping distances were observed among members of 13 wild wolf (Canis lupus) packs and 11 pairs in northeastern Minnesota to determine if the distances correlated with pack size and composition. The study utilized aerial radio-tracking and observation during winter. Pack size and number of adults per pack were inversely related to pack average sleeping distance and variability. No correlation between sleeping distance and microclimate was observed. Possible relationships between social bonding and our results are discussed.

  13. Distance-based classification of keystroke dynamics

    NASA Astrophysics Data System (ADS)

    Tran Nguyen, Ngoc

    2016-07-01

    This paper uses the keystroke dynamics in user authentication. The relationship between the distance metrics and the data template, for the first time, was analyzed and new distance based algorithm for keystroke dynamics classification was proposed. The results of the experiments on the CMU keystroke dynamics benchmark dataset1 were evaluated with an equal error rate of 0.0614. The classifiers using the proposed distance metric outperform existing top performing keystroke dynamics classifiers which use traditional distance metrics.

  14. Dimensions of distance: a comparison of classroom education and distance education.

    PubMed

    Kennedy, David M

    2002-07-01

    Distance is obviously a core issue in distance education. But distance is a factor in classroom-based education as well. Classroom-based teachers and distance educators have a common interest in the dynamics of distance. The focus of much discussion in distance education is on geographical distance and how it may be bridged. However, this focus obscures the more fundamental issue of educational distance. Educational distance includes cognitive distance, role distance and access distance. This form of distance is as potent in the classroom environment as it is in a virtual learning environment. The writer explores this theme by his analysis of the communication patterns between teacher and students in one module in a BSc Health Studies degree programme. The writer has taught this module in both distance education format and in traditional classroom-based format. His finding is that the communication time between the teacher and students in the distance education form of the module is 29% greater than the communication time in the classroom-based form. The most significant feature of the communication pattern is the greater quantity of individual communication between student and teacher in the distance education format. Both the quantity and type of the communication in each of these modes suggest that the more communication-rich distance education format has greater potential for overcoming the problems of educational distance within this module.

  15. Distance effects in electrochemical micromachining

    PubMed Central

    Xu, Lizhong; Pan, Yue; Zhao, Chuanjun

    2016-01-01

    Considering exponential dependence of currents on double-layer voltage and the feedback effect of the electrolyte resistance, a distance effect in electrochemical micromachining is found, namely that both time constant and double-layer voltage depend on the separation of electrodes. The double-layer voltage is the real voltage used in processing. Under DC voltage, the apparent voltages between two electrodes are constant for different separations, but the real voltages change with the separations. Small separations exert substantial effects on the real voltages. Accordingly, a DC-voltage small-separation electrochemical micromachining technique was proposed. The double-layer voltage drops sharply as the small separation increases. Thus, the electrochemical reactions are confined to electrode regions in very close proximity even under DC voltage. The machining precision can be significantly enhanced by reducing the voltage and separation between electrodes. With this technique, the machining of conducting materials with submicrometre precision was achieved. PMID:27581708

  16. Distance majorization and its applications.

    PubMed

    Chi, Eric C; Zhou, Hua; Lange, Kenneth

    2014-08-01

    The problem of minimizing a continuously differentiable convex function over an intersection of closed convex sets is ubiquitous in applied mathematics. It is particularly interesting when it is easy to project onto each separate set, but nontrivial to project onto their intersection. Algorithms based on Newton's method such as the interior point method are viable for small to medium-scale problems. However, modern applications in statistics, engineering, and machine learning are posing problems with potentially tens of thousands of parameters or more. We revisit this convex programming problem and propose an algorithm that scales well with dimensionality. Our proposal is an instance of a sequential unconstrained minimization technique and revolves around three ideas: the majorization-minimization principle, the classical penalty method for constrained optimization, and quasi-Newton acceleration of fixed-point algorithms. The performance of our distance majorization algorithms is illustrated in several applications.

  17. Time delay and distance measurement

    NASA Technical Reports Server (NTRS)

    Abshire, James B. (Inventor); Sun, Xiaoli (Inventor)

    2011-01-01

    A method for measuring time delay and distance may include providing an electromagnetic radiation carrier frequency and modulating one or more of amplitude, phase, frequency, polarization, and pointing angle of the carrier frequency with a return to zero (RZ) pseudo random noise (PN) code. The RZ PN code may have a constant bit period and a pulse duration that is less than the bit period. A receiver may detect the electromagnetic radiation and calculate the scattering profile versus time (or range) by computing a cross correlation function between the recorded received signal and a three-state RZ PN code kernel in the receiver. The method also may be used for pulse delay time (i.e., PPM) communications.

  18. 47 CFR 73.6008 - Distance computations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Distance computations. 73.6008 Section 73.6008 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6008 Distance computations. The distance between two...

  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 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such...

  20. 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 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Distance, stopping. The maximum distance on any portion of any railroad which any train operating on such...

  1. 47 CFR 73.6008 - Distance computations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Distance computations. 73.6008 Section 73.6008 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6008 Distance computations. The distance between two...

  2. Distance Learning: Silver Bullet or Educational Apartheid?

    ERIC Educational Resources Information Center

    Greer-Pitt, Sue

    This paper discusses why distance education is not the cure all that political leaders hope it will be, and outlines some of the reasons why distance education sometimes results in education that is separate and unequal. It identifies some of the major categories of distance education: correspondence courses, one-way televised courses (broadcast,…

  3. ETUDE - European Trade Union Distance Education.

    ERIC Educational Resources Information Center

    Creanor, Linda; Walker, Steve

    2000-01-01

    Describes transnational distance learning activities among European trade union educators carried out as part of the European Trade Union Distance Education (ETUDE) project, supported by the European Commission. Highlights include the context of international trade union distance education; tutor training course; tutors' experiences; and…

  4. Quality Assurance in Distance Learning Libraries

    ERIC Educational Resources Information Center

    Tripathi, Manorama; Jeevan, V. K. J.

    2009-01-01

    Purpose: The paper aims to study how the present distance learning libraries can improve upon their existing services and introduce new ones to enhance quality of services to distance learners. Design/methodology/approach: The paper includes a review of literature on quality assurance in open and distance education in general and student support…

  5. Student Orientation in the Distance Education Classroom.

    ERIC Educational Resources Information Center

    Bergmann, Marilyn; Raleigh, Donna

    Institutions offering distance education courses realize the value that well-trained and well-prepared faculty contribute to the success of their distance education programs. However, taking approximately a half-hour in the first session of any course to prepare the students for their distance education experience will add to the success of the…

  6. Calibrating Reach Distance to Visual Targets

    ERIC Educational Resources Information Center

    Mon-Williams, Mark; Bingham, Geoffrey P.

    2007-01-01

    The authors investigated the calibration of reach distance by gradually distorting the haptic feedback obtained when participants grasped visible target objects. The authors found that the modified relationship between visually specified distance and reach distance could be captured by a straight-line mapping function. Thus, the relation could be…

  7. Distance Education Practices at One Community College.

    ERIC Educational Resources Information Center

    Abram, Suzanne L.

    This paper examines distance education at one community college, providing data on the strengths and weaknesses of distance learning and the effectiveness of various delivery methods. Part 1 offers an account of one student's concerns about a distance education course focusing on logic and computers. The student was enrolled in an electronics…

  8. Perspectives of Research on Distance Education.

    ERIC Educational Resources Information Center

    Holmberg, Borje

    The history of research on distance education was studied. Major research done on distance education in such diverse areas as the United States, Venezuela, and Europe was analyzed. It was discovered that the earliest attempts to develop theories of distance education were mainly concerned with identifying its very concept. Like most educational…

  9. Analysing designed experiments in distance sampling

    Treesearch

    Stephen T. Buckland; Robin E. Russell; Brett G. Dickson; Victoria A. Saab; Donal N. Gorman; William M. Block

    2009-01-01

    Distance sampling is a survey technique for estimating the abundance or density of wild animal populations. Detection probabilities of animals inherently differ by species, age class, habitats, or sex. By incorporating the change in an observer's ability to detect a particular class of animals as a function of distance, distance sampling leads to density estimates...

  10. Rough Way for Academics: Distance Education

    ERIC Educational Resources Information Center

    Gursul, Fatih

    2010-01-01

    This study aims to compare the academics' perceptions about face to face and distance education, beside finding out the contributions of distance education to them, difficulties they experience in synchronous and asynchronous distance education environments and suggestions for possible solutions of the existing problems. The sample consists of 52…

  11. Learning at a Distance: Engaged or Not?

    ERIC Educational Resources Information Center

    Chen, Pu-Shih Daniel; Gonyea, Robert; Kuh, George

    2008-01-01

    In this study, Pu-Shih Chen, Robert Gonyea, and George Kuh compare the engagement of distance learners in educationally effective activities with that of their campus-based counterparts and compare the engagement of older distance learners relative to younger online students. Although distance learning is the fastest growing segment of…

  12. The History of Distance Education in Australia

    ERIC Educational Resources Information Center

    Stacey, Elizabeth

    2005-01-01

    Australia's large distances and widely distributed population has meant that distance education has been an important part of its history. From the earliest provision of schooling by mail through a series of correspondence schools, both state and federal governments have provided a sound infrastructure to support distance education. Innovative…

  13. Quality Assurance in Distance Learning Libraries

    ERIC Educational Resources Information Center

    Tripathi, Manorama; Jeevan, V. K. J.

    2009-01-01

    Purpose: The paper aims to study how the present distance learning libraries can improve upon their existing services and introduce new ones to enhance quality of services to distance learners. Design/methodology/approach: The paper includes a review of literature on quality assurance in open and distance education in general and student support…

  14. Distance Education at Conventional Universities in Germany.

    ERIC Educational Resources Information Center

    Kappel, Hans-Henning; Lehmann, Burkhard; Loeper, Joachim

    2002-01-01

    Reviews developments in German distance education from the Fernuniversitat in the 1970s to the hybridized (face-to-face and distance education) programs at conventional universities. Discusses the work of the German Association for Distance Education and two dual-mode programs: the master of arts degree at the University of Koblenz-Landau and the…

  15. Tidewater Community College Distance Learning Report.

    ERIC Educational Resources Information Center

    Tidewater Community Coll., Norfolk, VA.

    This study of distance learning at Tidewater Community College (TCC) was conducted to determine enrollment patterns, retention, and success in distance learning courses and student perceptions. Distance learning was defined as students enrolled in one of three modes of course delivery: telecourse, online, and compressed video. The time frame for…

  16. Distance Education in Asia and the Pacific.

    ERIC Educational Resources Information Center

    Cahill, Bruce, Ed.

    1985-01-01

    Issues related to the use of distance education are discussed in this bulletin, which also summarizes the status of distance education in 26 countries of Asia and the Pacific. Section 1 contains a rationale for distance education and points out possibilities offered by advances in communication technologies. Section 2 gives country-by-country…

  17. Distance Education in Papua New Guinea.

    ERIC Educational Resources Information Center

    Avalos, Beatrice, Ed.

    1991-01-01

    The theme of this special double serial issue is "Distance Education in Papua New Guinea." The following articles are featured: (1) "Distance Education in Papua New Guinea" (John Lynch); (2) "Distance Education in Papua New Guinea: Context, Issues and Prospects" (Michael Crossley and Richard Guy); (3) "Distance…

  18. Learning at a Distance: Engaged or Not?

    ERIC Educational Resources Information Center

    Chen, Pu-Shih Daniel; Gonyea, Robert; Kuh, George

    2008-01-01

    In this study, Pu-Shih Chen, Robert Gonyea, and George Kuh compare the engagement of distance learners in educationally effective activities with that of their campus-based counterparts and compare the engagement of older distance learners relative to younger online students. Although distance learning is the fastest growing segment of…

  19. Distance Education Support in University Libraries

    ERIC Educational Resources Information Center

    Snyder, Carolyn A.; Carter, Howard; Hostetler, Jerry C.

    2004-01-01

    This article describes the current distance education environment for university libraries and the distance education library services for faculty and students. The authors surveyed selected Association of Research Libraries (ARL) members to determine current services and the changes in distance education library services since the 1996 ARL SPEC…

  20. The Distancing Question in Online Education

    ERIC Educational Resources Information Center

    Russell, Glenn

    2005-01-01

    Intellectuals in many fields have long argued that, as the distance between people increases, the possibility for genuine empathy between them decreases. In this article, the author argues that distancing has as-yet unexplored pragmatic consequences in online education. As he has argued elsewhere (Russell 2004), distancing can be understood as…

  1. 2007-08 Distance Education Report

    ERIC Educational Resources Information Center

    Nevada System of Higher Education, 2008

    2008-01-01

    This report focuses on distance education within the Nevada System of Higher Education (NSHE) for the 2007-08 academic year and provides documentation of the substantial growth of distance education within all colleges and universities. Distance education is a field of continuous improvement and change, and NSHE institutions are constantly…

  2. Transformation a Echelle Fixe et Groupe de Renormalisation pour les Objets Fractals et Multifractals

    NASA Astrophysics Data System (ADS)

    Tremblay, Real

    Dans un premier temps, la description mathematique des fractals et des multifractais est resumee. Une description de quelques-uns des principaux systemes ou apparaissent des spectres d'exposants multifractals est presentee. L'accent est mis sur deux archetypes, le modele de percolation et le modele de rupture dielectrique. Un modele original de cascade multifractale avec interactions inspire des modeles phenomenologiques de la turbulence est presente et son spectre d'exposants calcule analytiquement. Ce travail elargit la classe de modeles pour lesquels on connait le spectre d'exposants exactement. Dans la seconde partie, on trouve une analyse critique de la transformation a echelle fixe. Sont discutees plus particulierement les proprietes que doivent posseder les diagrammes de base pour obtenir une transformation invariante d'echelle. Les differentes hypotheses arbitraires de la theorie sont mises en evidence. L'une de ces hypotheses concerne le traitement auto-coherent des conditions aux frontieres. Considerant cette hypothese comme valable, la theorie utilise la distribution de trous dans un ensemble de Cantor aleatoire. Un calcul exact de cette distribution est donne ici. Enfin, en troisieme et dernier lieu, on retrouve une analyse exhaustive du probleme du crossover dans le modele de percolation avec une resistance non-nulle pour les liens normalement isolants. A l'aide du groupe de renormalisation de Migdal-Kadanoff, on montre qu'il existe un seul exposant de crossover et une seule longueur de coherence. D'autres longueurs de correlation peuvent etre definies, mais elles demeurent dans un rapport fixe le long des axes propres du groupe de renormalisation. La multifractalite est donc, pour ce modele et ceux qui peuvent etre formules de facon analogue, compatible avec l'existence d'une seule longueur de coherence. Ces resultats sont d'application directe pour les proprietes electriques des milieux desordonnes.

  3. Bhattacharyya distance based video scene change detection

    NASA Astrophysics Data System (ADS)

    Shen, Bichuan; Chen, C. H.

    2009-10-01

    This paper studies statistics based scene change detection in the video streaming scenario, and three scene feature metrics including histogram distance, chi-square distance, and Bhattacharyya distance have been investigated. With the unique characteristics of triangular inequality and non-singularity, Bhattacharyya distance has been proposed as a viable scene change metrics. It outperforms much better than the other two in that it calculates and maximizes the feature vector distance between multi-modal clusters in a hyper-sphere space. The experiments are conducted and the precision recall statistics are compared, and the results support our analysis.

  4. From language identification to language distance

    NASA Astrophysics Data System (ADS)

    Gamallo, Pablo; Pichel, José Ramom; Alegria, Iñaki

    2017-10-01

    In this paper, we define two quantitative distances to measure how far apart two languages are. The distance measure that we have identified as more accurate is based on the perplexity of n-gram models extracted from text corpora. An experiment to compare forty-four European languages has been performed. For this purpose, we computed the distances for all the possible language pairs and built a network whose nodes are languages and edges are distances. The network we have built on the basis of linguistic distances represents the current map of similarities and divergences among the main languages of Europe.

  5. The minimum distance approach to classification

    NASA Technical Reports Server (NTRS)

    Wacker, A. G.; Landgrebe, D. A.

    1971-01-01

    The work to advance the state-of-the-art of miminum distance classification is reportd. This is accomplished through a combination of theoretical and comprehensive experimental investigations based on multispectral scanner data. A survey of the literature for suitable distance measures was conducted and the results of this survey are presented. It is shown that minimum distance classification, using density estimators and Kullback-Leibler numbers as the distance measure, is equivalent to a form of maximum likelihood sample classification. It is also shown that for the parametric case, minimum distance classification is equivalent to nearest neighbor classification in the parameter space.

  6. Laser Doppler distance sensor using phase evaluation.

    PubMed

    Günther, P; Pfister, T; Büttner, L; Czarske, J

    2009-02-16

    This paper presents a novel optical sensor which allows simultaneous measurements of axial position and tangential velocity of moving solid state objects. An extended laser Doppler velocimeter setup is used with two slightly tilted interference fringe systems. The distance to a solid state surface can be determined via a phase evaluation. The phase laser Doppler distance sensor offers a distance resolution of 150 nm and a total position uncertainty below 1 microm. Compared to conventional measurement techniques, such as triangulation, the distance resolution is independent of the lateral surface velocity. This advantage enables precise distance and shape measurements of fast rotating surfaces.

  7. KINEMATIC DISTANCES OF GALACTIC PLANETARY NEBULAE

    SciTech Connect

    Yang, A. Y.; Tian, W. W.; Zhu, H.; Wu, D.; Leahy, D. A. E-mail: ayyang@bao.ac.cn

    2016-03-15

    We construct H i absorption spectra for 18 planetary nebulae (PNs) and their background sources using data from the International Galactic Plane Survey. We estimate the kinematic distances of these PNs, among which 15 objects’ kinematic distances are obtained for the first time. The distance uncertainties of 13 PNs range from 10% to 50%, which is a significant improvement with uncertainties of a factor of two or three smaller than most previous distance measurements. We confirm that PN G030.2−00.1 is not a PN because of its large distance found here.

  8. Galaxy Cluster Smashes Distance Record

    NASA Astrophysics Data System (ADS)

    2009-10-01

    he most distant galaxy cluster yet has been discovered by combining data from NASA's Chandra X-ray Observatory and optical and infrared telescopes. The cluster is located about 10.2 billion light years away, and is observed as it was when the Universe was only about a quarter of its present age. The galaxy cluster, known as JKCS041, beats the previous record holder by about a billion light years. Galaxy clusters are the largest gravitationally bound objects in the Universe. Finding such a large structure at this very early epoch can reveal important information about how the Universe evolved at this crucial stage. JKCS041 is found at the cusp of when scientists think galaxy clusters can exist in the early Universe based on how long it should take for them to assemble. Therefore, studying its characteristics - such as composition, mass, and temperature - will reveal more about how the Universe took shape. "This object is close to the distance limit expected for a galaxy cluster," said Stefano Andreon of the National Institute for Astrophysics (INAF) in Milan, Italy. "We don't think gravity can work fast enough to make galaxy clusters much earlier." Distant galaxy clusters are often detected first with optical and infrared observations that reveal their component galaxies dominated by old, red stars. JKCS041 was originally detected in 2006 in a survey from the United Kingdom Infrared Telescope (UKIRT). The distance to the cluster was then determined from optical and infrared observations from UKIRT, the Canada-France-Hawaii telescope in Hawaii and NASA's Spitzer Space Telescope. Infrared observations are important because the optical light from the galaxies at large distances is shifted into infrared wavelengths because of the expansion of the universe. The Chandra data were the final - but crucial - piece of evidence as they showed that JKCS041 was, indeed, a genuine galaxy cluster. The extended X-ray emission seen by Chandra shows that hot gas has been detected

  9. ON PULSAR DISTANCE MEASUREMENTS AND THEIR UNCERTAINTIES

    SciTech Connect

    Verbiest, J. P. W.; Lee, K. J.; Weisberg, J. M.; Chael, A. A.; Lorimer, D. R.

    2012-08-10

    Accurate distances to pulsars can be used for a variety of studies of the Galaxy and its electron content. However, most distance measures to pulsars have been derived from the absorption (or lack thereof) of pulsar emission by Galactic H I gas, which typically implies that only upper or lower limits on the pulsar distance are available. We present a critical analysis of all measured H I distance limits to pulsars and other neutron stars, and translate these limits into actual distance estimates through a likelihood analysis that simultaneously corrects for statistical biases. We also apply this analysis to parallax measurements of pulsars in order to obtain accurate distance estimates and find that the parallax and H I distance measurements are biased in different ways, because of differences in the sampled populations. Parallax measurements typically underestimate a pulsar's distance because of the limited distance to which this technique works and the consequential strong effect of the Galactic pulsar distribution (i.e., the original Lutz-Kelker bias), in H I distance limits, however, the luminosity bias dominates the Lutz-Kelker effect, leading to overestimated distances because the bright pulsars on which this technique is applicable are more likely to be nearby given their brightness.

  10. Learner characteristics involved in distance learning

    SciTech Connect

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  11. Optical Communications from Planetary Distances

    NASA Technical Reports Server (NTRS)

    Davarian, F.; Farr, W.; Hemmati, H.; Piazzolla, S.

    2008-01-01

    Future planetary campaigns, including human missions, will require data rates difficult to realize by microwave links. Optical channels not only provide an abundance of bandwidth, they also allow for significant size, weight, and power reduction. Moreover, optical-based tracking may enhance spacecraft navigation with respect to microwave-based tracking. With all its advantages, optical communications from deep space is not without its challenges. Due to the extreme distance between the two ends of the link, specialized technologies are needed to enable communications in the deep space environment. Although some of the relevant technologies have been developed in the last decade, they remain to be validated in an appropriate domain. The required assets include efficient pulsed laser sources, modulators, transmitters, receivers, detectors, channel encoders, precise beam pointing technologies for the flight transceiver and large apertures for the ground receiver. Clearly, space qualification is required for the systems that are installed on a deep space probe. Another challenge is atmospheric effects on the optical beam. Typical candidate locations on the ground have a cloud-free line of sight only on the order of 60-70% of the time. Furthermore, atmospheric losses and background light can be problematic even during cloud-free periods. Lastly, operational methodologies are needed for efficient and cost effective management of optical links. For more than a decade, the National Aeronautics and Space Administration (NASA) has invested in relevant technologies and procedures to enable deep space optical communications capable of providing robust links with rates in the order of 1 Gb/s from Mars distance. A recent publication indicates that potential exists for 30-dB improvement in performance through technology development with respect to the state-of-the-art in the early years of this decade. The goal is to fulfill the deep space community needs from about 2020 to the

  12. Distance Education in Southern Africa Conference, 1987. Papers 1: The Theory and Practice of Distance Education.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Fifteen papers from the University of South Africa's Conference on Distance Education are presented on the theory and practice of distance education. Titles and authors include: "Evaluation at a Distance" (Margalit Ganor); "Can the Tables Be Turned? Likelihood That Distance Teaching at University Can Be More Effective Than…

  13. Media in Distance Learning: The Nigerian National Teachers Institute Distance Education Programme

    ERIC Educational Resources Information Center

    Yusuf, Mudasiru Olalere; Falade, Ayotunde Atanda

    2005-01-01

    This study investigated the use of media by distance learners enrolled in the NTI distance education programme. Two hundred and fifty five distance learners drawn from Oyo State, Nigeria, completed a questionnaire to determine the use of media, and factors militating against their effective use by distance learners. Research data were analyzed…

  14. Web-Based Communications, the Internet, and Distance Education. Readings in Distance Education, Number 7.

    ERIC Educational Resources Information Center

    Moore, Michael G., Ed.; Cozine, Geoffrey T., Ed.

    This book brings together a selection of articles published in "The American Journal of Distance Education" that are related to Web-based delivery of distance education. Articles include: "Performance and Perceptions of Distance Learners in Cyberspace" (Peter Navarro and Judy Shoemaker); "Distance Education for Dentists: Improving the Quality of…

  15. Web-Based Communications, the Internet, and Distance Education. Readings in Distance Education, Number 7.

    ERIC Educational Resources Information Center

    Moore, Michael G., Ed.; Cozine, Geoffrey T., Ed.

    This book brings together a selection of articles published in "The American Journal of Distance Education" that are related to Web-based delivery of distance education. Articles include: "Performance and Perceptions of Distance Learners in Cyberspace" (Peter Navarro and Judy Shoemaker); "Distance Education for Dentists: Improving the Quality of…

  16. Long-Distance Free Fall

    NASA Astrophysics Data System (ADS)

    Gallant, Joseph

    1999-04-01

    One of the goals of physics education is to instill a sense of wonder in our students. We hope our natural curiosity will rub off on them and that they will apply the critical thinking skills we teach them to other aspects of their lives outside the classroom. As an example of this, consider the situation described in Milton's epic poem ``Paradise Lost''. Milton wrote that when the devil was cast out of heaven, he fell for nine days before landing in hell. In Milton's universe, hell is a separate place from Earth, but many people place hell at the center of the Earth. Based on these ideas, we can apply Newton's laws of motion to calculate the distance from heaven to Earth. This exercise is an example of the kind of intellectual exercise a physicist (or a physics student) might carry out when confronted with such information. We apply the basic principles of physics to a situation described in work of literature while making no attempt to validate or refute any philosophy, theology or ideology.

  17. Distance-weighted city growth.

    PubMed

    Rybski, Diego; García Cantú Ros, Anselmo; Kropp, Jürgen P

    2013-04-01

    Urban agglomerations exhibit complex emergent features of which Zipf's law, i.e., a power-law size distribution, and fractality may be regarded as the most prominent ones. We propose a simplistic model for the generation of citylike structures which is solely based on the assumption that growth is more likely to take place close to inhabited space. The model involves one parameter which is an exponent determining how strongly the attraction decays with the distance. In addition, the model is run iteratively so that existing clusters can grow (together) and new ones can emerge. The model is capable of reproducing the size distribution and the fractality of the boundary of the largest cluster. Although the power-law distribution depends on both, the imposed exponent and the iteration, the fractality seems to be independent of the former and only depends on the latter. Analyzing land-cover data, we estimate the parameter-value γ≈2.5 for Paris and its surroundings.

  18. Telehealth distance mentoring of students.

    PubMed

    Loera, José A; Kuo, Yong-Fang; Rahr, Richard R

    2007-02-01

    The challenge to the healthcare system lies in maintaining an adequately trained home care workforce of healthcare professionals in a time when government funding for educational geriatrics programs is limited, and academic centers are emphasizing faculty productivity that may limit their time dedicated to teaching and training healthcare students. Telemedicine presents an opportunity to study its educational potential using limited faculty resources. Is telemedicine technology appropriate for teaching skills needed to obtain a history and perform a physical examination on the elderly who choose to remain living in the community? We used telemedicine instruments to enable faculty to study the potential for teaching students the skills needed to perform a history and physical examination in an elderly person. The distance mentoring study was designed as a pilot-based on limited faculty time available to determine the effectiveness of teaching students using telemedicine. Students were also surveyed regarding the experience of visiting an independent living facility and about the reliability and their level of comfort using telemedicine. Most students found telemedicine to be reliable, most gained confidence and an acceptable level of comfort using telemedicine instruments to interact with elderly volunteer residents of an independent living facility. Students improved their physical examination skills and gained confidence administering special questionnaires (geriatric depression scale, Mini Mental State Examination [MMSE], clock drawing test, Tinetti Assessment) to elderly volunteers and recommended that all Physician Assistant (PA) program students should visit an independent living facility (ILF).

  19. Social learning across psychological distance.

    PubMed

    Kalkstein, David A; Kleiman, Tali; Wakslak, Cheryl J; Liberman, Nira; Trope, Yaacov

    2016-01-01

    While those we learn from are often close to us, more and more our learning environments are shifting to include more distant and dissimilar others. The question we examine in 5 studies is how whom we learn from influences what we learn and how what we learn influences from whom we choose to learn it. In Study 1, we show that social learning, in and of itself, promotes higher level (more abstract) learning than does learning based on one's own direct experience. In Studies 2 and 3, we show that when people learn from and emulate others, they tend to do so at a higher level when learning from a distant model than from a near model. Studies 4 and 5 show that thinking about learning at a higher (compared to a lower) level leads individuals to expand the range of others that they will consider learning from. Study 6 shows that when given an actual choice, people prefer to learn low-level information from near sources and high-level information from distant sources. These results demonstrate a basic link between level of learning and psychological distance in social learning processes.

  20. Superposition tridimensionnelle (3-D) sur la base du crâne pour l’évaluation longitudinale des effets de la croissance et du traitement

    PubMed Central

    Cevidanes, Lucia H.S.; Styner, Martin; Proffit, William R.; Ngom, Traduit par Papa Ibrahima

    2010-01-01

    RÉSUMÉ – Pour évaluer les modifications liées à la croissance ou au traitement, il est nécessaire de superposer les céphalogrammes successifs sur une structure stable. En céphalométrie bidimensionnelle (2-D), la base du crâne est souvent utilisée pour les superpositions parce que les changements qu’elle subit après le développement cérébral sont mineurs. Toutefois, sur les céphalogrammes de profil et de face, les points de repère basicraniens sont peu fiables. Dans cet article, nous présentons une nouvelle méthode de superposition tridimensionnelle (3-D) basée sur un enregistrement entièrement automatisé des intensités de voxels, au niveau de la surface de la base du crâne. Le progiciel utilisé permet l’évaluation quantitative des modifications qui apparaissent dans le temps, grâce au calcul de la distance euclidienne entre les surfaces du modèle tridimensionnel. Il permet également l’appréciation visuelle de l’emplacement et de l’importance des modifications au niveau des maxillaires, grâce à une surimpression graphique. Les modifications sont visualisées par comparaison à des tables de correspondance de couleur. On peut ainsi réaliser une étude détaillée des modes d’adaptation chez les patients dont la croissance et/ou le traitement ont provoqué des modifications squelettiques cliniquement significatives. PMID:19954732

  1. ANALYSIS OF DWPF SLUDGE BATCH 6 (MACROBATCH 7) POUR STREAM GLASS SAMPLES

    SciTech Connect

    Johnson, F.

    2012-01-20

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 6 (SB6), also referred to as Macrobatch 7 (MB7), in June 2010. SB6 is a blend of the heel of Tank 40 from Sludge Batch 5 (SB5), H-Canyon Np transfers and SB6 that was transferred to Tank 40 from Tank 51.1 SB6 was processed using Frit 418. Sludge is received into the DWPF Chemical Processing Cell (CPC) and is processed through the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator Tank (SME). The treated sludge slurry is then transferred to the Melter Feed Tank (MFT) and fed to the melter. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP) and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. The DWPF requested various analyses of radioactive glass samples obtained from the melter pour stream during processing of SB6 as well as reduction/oxidation (REDOX) analysis of MFT samples to determine the impact of Argon bubbling. Sample analysis followed the Task Technical and Quality Assurance Plan (TTQAP) and an Analytical Study Plan (ASP). Four Pour Stream (PS) glass samples and two MFT slurry samples were delivered to the Savannah River National Laboratory (SRNL) from the DWPF. Table 1-1 lists the sample information for each pour stream glass sample. SB6 PS3 (S03472) was selected as the official pour stream sample for SB6 and full analysis was requested. This report details the visual observations of the as-received SB6 PS No.3 glass sample as well as results for the chemical composition, Product Consistency Test (PCT), radionuclide content, noble metals, and glass density. REDOX results will be provided for all four pour stream samples and vitrified samples of MFT-558 and MFT-568A. Where appropriate, data from other pour stream samples will be provided.

  2. Distance probes of dark energy

    NASA Astrophysics Data System (ADS)

    Kim, A. G.; Padmanabhan, N.; Aldering, G.; Allen, S. W.; Baltay, C.; Cahn, R. N.; D'Andrea, C. B.; Dalal, N.; Dawson, K. S.; Denney, K. D.; Eisenstein, D. J.; Finley, D. A.; Freedman, W. L.; Ho, S.; Holz, D. E.; Kasen, D.; Kent, S. M.; Kessler, R.; Kuhlmann, S.; Linder, E. V.; Martini, P.; Nugent, P. E.; Perlmutter, S.; Peterson, B. M.; Riess, A. G.; Rubin, D.; Sako, M.; Suntzeff, N. V.; Suzuki, N.; Thomas, R. C.; Wood-Vasey, W. M.; Woosley, S. E.

    2015-03-01

    This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type Ia supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays. We note that these three elements together make a comprehensive DOE SN program, with a well- sequenced combination of R&D, construction, operations and analysis projects. The DOE SN researchers will be involved in several of these at any given time, since the precision SN cosmology measurement requires an in-depth understanding and use of SN data from all the redshift ranges simultaneously. A future Stage IV space-based SNe project would be the simplest way to match, at high redshift, these precision measurements of Type Ia supernovae at low redshift -measurements needed to provide the same systematics control over the entire redshift range from z ∼ 0.01 to z ∼ 2 . With modest investments in spectroscopic capabilities and a small fraction of mission time, WFIRST-AFTA could be upgraded [Editor's note: and has been upgraded in the current baseline; see Footnote2] to become this project, and would be complementary to the lensing programs of LSST/EUCLID. However, given the timescales and many difficulties of a space mission, there is now a need to explore vigorously a ground-based alternative to fill this important missing element in the DOE program. In particular, an R&D effort to explore the potential of novel ground-based techniques, combining near-IR technology with OH sky-line suppression, could make it possible to accomplish the precision measurements for SNe from SCP, DES, and LSST, complementing and strengthening these currently approved DOE projects.

  3. Robotic laboratory for distance education

    NASA Astrophysics Data System (ADS)

    Luciano, Sarah C.; Kost, Alan R.

    2016-09-01

    This project involves the construction of a remote-controlled laboratory experiment that can be accessed by online students. The project addresses a need to provide a laboratory experience for students who are taking online courses to be able to provide an in-class experience. The chosen task for the remote user is an optical engineering experiment, specifically aligning a spatial filter. We instrument the physical laboratory set up in Tucson, AZ at the University of Arizona. The hardware in the spatial filter experiment is augmented by motors and cameras to allow the user to remotely control the hardware. The user interacts with a software on their computer, which communicates with a server via Internet connection to the host computer in the Optics Laboratory at the University of Arizona. Our final overall system is comprised of several subsystems. These are the optical experiment set-up, which is a spatial filter experiment; the mechanical subsystem, which interfaces the motors with the micrometers to move the optical hardware; the electrical subsystem, which allows for the electrical communications from the remote computer to the host computer to the hardware; and finally the software subsystem, which is the means by which messages are communicated throughout the system. The goal of the project is to convey as much of an in-lab experience as possible by allowing the user to directly manipulate hardware and receive visual feedback in real-time. Thus, the remote user is able to learn important concepts from this particular experiment and is able to connect theory to the physical world by actually seeing the outcome of a procedure. The latter is a learning experience that is often lost with distance learning and is one that this project hopes to provide.

  4. Quantum Electrodynamics at Small Distances

    NASA Astrophysics Data System (ADS)

    Gell-Mann, M.; Low, F. E.

    The renormalized propagation functions DFC and SFC for photons and electrons, respectively, are investigated for momenta much greater than the mass of the electron. It is found that in this region the individual terms of the perturbation series to all orders in the coupling constant take on very simple asymptotic forms. An attempt to sum the entire series is only partially successful. It is found that the series satisfy certain functional equations by virtue of the renormalizability of the theory. If photon self-energy parts are omitted from the series, so that DFC=DF, then SFC has the asymptotic form A[p2/m2]n[iγ·p]-1, where A = A(e12) and n = n(e12). When all diagrams are included, less specific results are found. One conclusion is that the shape of the charge distribution surrounding a test charge in the vacuum does not, at small distances, depend on the coupling constant except through a scale factor. The behavior of the propagation functions for large momenta is related to the magnitude of the renormalization constants in the theory. Thus it is shown that the unrenormalized coupling constant e02/4πħc, which appears in perturbation theory as a power series in the renormalized coupling constant e12/4πħc with divergent coefficients, may behave in either of two ways: (a) It may really be infinite as perturbation theory indicates; (b) It may be a finite number independent of e12/4πħc.

  5. Giant Sparks at Cosmological Distances?

    NASA Astrophysics Data System (ADS)

    Kulkarni, S. R.; Ofek, E. O.; Neill, J. D.; Zheng, Z.; Juric, M.

    2014-12-01

    Millisecond-duration bright radio pulses at 1.4 GHz with high dispersion measures (DMs) were reported by Lorimer et al., Keane et al., and Thornton et al. Their all-sky rate is ≈104 day-1 above ~1 Jy. Related events are "Perytons"—similar pulsed, dispersed sources, but most certainly local. Suggested models of fast radio bursts (FRBs) can originate in Earth's atmosphere, in stellar coronae, in other galaxies, and even at cosmological distances. Using physically motivated assumptions combined with observed properties, we explore these models. In our analysis, we focus on the Lorimer event: a 30 Jy, 5 ms duration burst with DM = 375 cm-3 pc, exhibiting a steep frequency-dependent pulse width (the Sparker). To be complete, we drop the assumption that high DMs are produced by plasma propagation and assume that the source produces pulses with frequency-dependent arrival time ("chirped signals"). Within this framework, we explore a scenario in which Perytons, the Sparker, and the FRBs are all atmospheric phenomena occurring at different heights. This model is ad hoc in that we cannot explain why Perytons at higher altitudes show greater DMs or exhibit narrower pulses. Nonetheless, we argue that the Sparker may be a Peryton. We end with two remarks. First, the detection of a single FRB by an interferometer with a kilometer (or longer) baseline will prove that FRBs are of extraterrestrial origin. Second, we urge astronomers to pursue observations and understanding of Perytons since they form (at least) a formidable foreground for the FRBs.

  6. Giant sparks at cosmological distances?

    SciTech Connect

    Kulkarni, S. R.; Ofek, E. O.; Neill, J. D.; Zheng, Z.; Juric, M.

    2014-12-10

    Millisecond-duration bright radio pulses at 1.4 GHz with high dispersion measures (DMs) were reported by Lorimer et al., Keane et al., and Thornton et al. Their all-sky rate is ≈10{sup 4} day{sup –1} above ∼1 Jy. Related events are 'Perytons'–similar pulsed, dispersed sources, but most certainly local. Suggested models of fast radio bursts (FRBs) can originate in Earth's atmosphere, in stellar coronae, in other galaxies, and even at cosmological distances. Using physically motivated assumptions combined with observed properties, we explore these models. In our analysis, we focus on the Lorimer event: a 30 Jy, 5 ms duration burst with DM = 375 cm{sup –3} pc, exhibiting a steep frequency-dependent pulse width (the Sparker). To be complete, we drop the assumption that high DMs are produced by plasma propagation and assume that the source produces pulses with frequency-dependent arrival time ('chirped signals'). Within this framework, we explore a scenario in which Perytons, the Sparker, and the FRBs are all atmospheric phenomena occurring at different heights. This model is ad hoc in that we cannot explain why Perytons at higher altitudes show greater DMs or exhibit narrower pulses. Nonetheless, we argue that the Sparker may be a Peryton. We end with two remarks. First, the detection of a single FRB by an interferometer with a kilometer (or longer) baseline will prove that FRBs are of extraterrestrial origin. Second, we urge astronomers to pursue observations and understanding of Perytons since they form (at least) a formidable foreground for the FRBs.

  7. Laser triangulation: fundamental uncertainty in distance measurement.

    PubMed

    Dorsch, R G; Häusler, G; Herrmann, J M

    1994-03-01

    We discuss the uncertainty limit in distance sensing by laser triangulation. The uncertainty in distance measurement of laser triangulation sensors and other coherent sensors is limited by speckle noise. Speckle arises because of the coherent illumination in combination with rough surfaces. A minimum limit on the distance uncertainty is derived through speckle statistics. This uncertainty is a function of wavelength, observation aperture, and speckle contrast in the spot image. Surprisingly, it is the same distance uncertainty that we obtained from a single-photon experiment and from Heisenberg's uncertainty principle. Experiments confirm the theory. An uncertainty principle connecting lateral resolution and distance uncertainty is introduced. Design criteria for a sensor with minimum distanc uncertainty are determined: small temporal coherence, small spatial coherence, a large observation aperture.

  8. Distance and Cable Length Measurement System

    PubMed Central

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  9. Spectroscopic thermometry for long-distance surveying.

    PubMed

    Tomberg, Teemu; Fordell, Thomas; Jokela, Jorma; Merimaa, Mikko; Hieta, Tuomas

    2017-01-10

    Electronic distance meters are routinely used to accurately determine the distance between two points. To reach relative measurement uncertainties of 10-7, the average temperature along the beam has to be known within 100 mK since it is a key component in determining the refractive index of air. Temperature measurements at this level are extremely challenging over long distances and especially in an outdoor environment. This paper presents a thermometer for accurate temperature measurements over distances up to a few km. The thermometer is based on direct laser absorption spectroscopy of oxygen near 770 nm. The thermometer yields a spatially continuous measurement of air temperature, and it can provide spatially and temporally well-matching data with an actual distance-measuring laser beam. A field measurement campaign at the 864-m Nummela standard baseline demonstrates applicability of the developed thermometer for improving the refractive index compensation of current high-performance electronic distance meters.

  10. Effects of pouring temperature and slurry viscosity on heat transfer and surface roughness in lost foam casting

    NASA Astrophysics Data System (ADS)

    Shayganpour, A.; Idris, M. H.; Izman, S.; Farahany, S.

    2012-06-01

    The effects of pouring temperature and slurry viscosity in terms of heat transfer on surface roughness during lost foam casting (LFC) of LM6 alloy were investigated experimentally. Heat transfer of molten materials is an important factors to changes the microstructure which is considered in the present study. It is primarily dependent on the pouring temperature, casting thickness, mould material, mould temperature and surrounding medium. The pouring temperature changed from 700 to740°C and slurry viscosity altered from 20 to 36 sec. A full 2-level factorial design experimental technique was used to identify the significant factors that effect on surface roughness of castings. The results show that surface roughness improved by lower pouring temperature, whereas slurry viscosity has less influence on the quality of surface.

  11. Que peut-on voir avec des neutrons? Une introduction pour des non spécialistes

    NASA Astrophysics Data System (ADS)

    Schweizer, J.

    2005-11-01

    Le neutron est une particule élémentaire qui a été découverte en 1932 par James Chadwick. Ses caractéristiques principales sont résumées dans le tableau I. Il a été utilisé pour la première fois par Clifford Shull en 1946 comme outil pour des expériences de diffusion. Cette technique s'est depuis constamment développée pour concerner tous les aspects de la matière condensée: physique, chimie, matériaux, biologie. Il s'agit d'un outil tout à fait exceptionnel car le neutron possède des propriétés uniques et particulièrement adaptées pour ces études.

  12. Prospects of Biometrics at-a-Distance

    DTIC Science & Technology

    2015-09-01

    facial recognition binocular system reviewed in this thesis is designed to enable users to conduct facial recognition at-a-distance to provide a covert... system reviewed in this thesis is designed to enable users to conduct facial recognition at-a-distance to provide a covert, biometric collection method...does not have the capability to collect biometric data at-a-distance. The system is designed for contact and contactless biometric collection, which

  13. Cardiovascular Risks in Long Distance Runners.

    PubMed

    Witham, Bethany Rolfe; Babbitt, Keven

    Distance running has become increasingly popular since the 1970s. Despite the health benefits, long-distance running has been associated with an increased risk for cardiac events. Healthcare professionals should be familiar with distance running cardiac risk factors and preparticipation screening recommendations from the American Heart Association, and should screen and educate patients during healthcare encounters. Nurses are particularly well suited to educate runners on risks and symptoms of cardiac dysfunction.

  14. An independent Cepheid distance scale: Current status

    NASA Technical Reports Server (NTRS)

    Barnes, T. G., III

    1980-01-01

    An independent distance scale for Cepheid variables is discussed. The apparent magnitude and the visual surface brightness, inferred from an appropriate color index, are used to determine the angular diameter variation of the Cepheid. When combined with the linear displacement curve obtained from the integrated radial velocity curve, the distance and linear radius are determined. The attractiveness of the method is its complete independence of all other stellar distance scales, even though a number of practical difficulties currently exist in implementing the technique.

  15. Optical distance measurement device and method thereof

    DOEpatents

    Bowers, Mark W.

    2003-05-27

    A system and method of efficiently obtaining distance measurements of a target. A modulated optical beam may be used to determine the distance to the target. A first beam splitter may be used to split the optical beam and a second beam splitter may be used to recombine a reference beam with a return ranging beam. An optical mixing detector may be used in a receiver to efficiently detect distance measurement information.

  16. Numerical Study of Impingement Location of Liquid Jet Poured from a Tilting Ladle with Lip Spout

    NASA Astrophysics Data System (ADS)

    Castilla, R.; Gamez-Montero, P. J.; Raush, G.; Khamashta, M.; Codina, E.

    2017-04-01

    A new approach for simulating liquid poured from a tilting lip spout is presented, using neither a dynamic mesh nor the moving solid solution method. In this case only the tilting ladle is moving, so we propose to rotate the gravitational acceleration at an angular velocity prescribed by a geometrical and dynamical calculation to keep the poured flow rate constant. This angular velocity is applied to modify the orientation of the gravity vector in computational fluid dynamics (CFD) simulations using the OpenFOAM® toolbox. Also, fictitious forces are considered. The modified solver is used to calculate the impingement location for six spout geometries and compare the jet dispersion there. This method could offer an inexpensive tool to calculate optimal spout geometries to reduce sprue size in the metal casting industry.

  17. Efficacy of eprinomectin pour-on against Rhipicephalus (Boophilus) microplus on buffaloes.

    PubMed

    Nazir, T; Katoch, R; Godara, R; Yadav, Anish

    2013-10-01

    A trial was conducted on 12 buffaloes naturally infested with Rhipicephalus (Boophilus) microplus to evaluate the efficacy of eprinomectin pour-on at a dose of 0.5 mg/kg body weight. A reduction in live tick count by 45.94, 63.96, 81.53, 90.54, 98.19 and 100 % was observed on days 3, 5, 7, 10, 14 and 21 post-treatment, respectively. The reinfestation of ticks was not observed up to 42 days of trial period. On the basis of the present trial of eprinomectin pour-on, it can be recommended for use in dairy buffaloes against Rhipicephalus (Boophilus) microplus infestation.

  18. A Cognitively Grounded Measure of Pronunciation Distance

    PubMed Central

    Wieling, Martijn; Nerbonne, John; Bloem, Jelke; Gooskens, Charlotte; Heeringa, Wilbert; Baayen, R. Harald

    2014-01-01

    In this study we develop pronunciation distances based on naive discriminative learning (NDL). Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is grounded in cognitive theory of competitive reinforcement learning and is able to generate asymmetrical pronunciation distances. In a first study, we validated the NDL-based pronunciation distances by comparing them to a large set of native-likeness ratings given by native American English speakers when presented with accented English speech. In a second study, the NDL-based pronunciation distances were validated on the basis of perceptual dialect distances of Norwegian speakers. Results indicated that the NDL-based pronunciation distances matched perceptual distances reasonably well with correlations ranging between 0.7 and 0.8. While the correlations were comparable to those obtained using the Levenshtein distance, the NDL-based approach is more flexible as it is also able to incorporate acoustic information other than sound segments. PMID:24416119

  19. A cognitively grounded measure of pronunciation distance.

    PubMed

    Wieling, Martijn; Nerbonne, John; Bloem, Jelke; Gooskens, Charlotte; Heeringa, Wilbert; Baayen, R Harald

    2014-01-01

    In this study we develop pronunciation distances based on naive discriminative learning (NDL). Measures of pronunciation distance are used in several subfields of linguistics, including psycholinguistics, dialectology and typology. In contrast to the commonly used Levenshtein algorithm, NDL is grounded in cognitive theory of competitive reinforcement learning and is able to generate asymmetrical pronunciation distances. In a first study, we validated the NDL-based pronunciation distances by comparing them to a large set of native-likeness ratings given by native American English speakers when presented with accented English speech. In a second study, the NDL-based pronunciation distances were validated on the basis of perceptual dialect distances of Norwegian speakers. Results indicated that the NDL-based pronunciation distances matched perceptual distances reasonably well with correlations ranging between 0.7 and 0.8. While the correlations were comparable to those obtained using the Levenshtein distance, the NDL-based approach is more flexible as it is also able to incorporate acoustic information other than sound segments.

  20. Maximum likelihood estimates of pairwise rearrangement distances.

    PubMed

    Serdoz, Stuart; Egri-Nagy, Attila; Sumner, Jeremy; Holland, Barbara R; Jarvis, Peter D; Tanaka, Mark M; Francis, Andrew R

    2017-06-21

    Accurate estimation of evolutionary distances between taxa is important for many phylogenetic reconstruction methods. Distances can be estimated using a range of different evolutionary models, from single nucleotide polymorphisms to large-scale genome rearrangements. Corresponding corrections for genome rearrangement distances fall into 3 categories: Empirical computational studies, Bayesian/MCMC approaches, and combinatorial approaches. Here, we introduce a maximum likelihood estimator for the inversion distance between a pair of genomes, using a group-theoretic approach to modelling inversions introduced recently. This MLE functions as a corrected distance: in particular, we show that because of the way sequences of inversions interact with each other, it is quite possible for minimal distance and MLE distance to differently order the distances of two genomes from a third. The second aspect tackles the problem of accounting for the symmetries of circular arrangements. While, generally, a frame of reference is locked, and all computation made accordingly, this work incorporates the action of the dihedral group so that distance estimates are free from any a priori frame of reference. The philosophy of accounting for symmetries can be applied to any existing correction method, for which examples are offered. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Absolute Distance Measurement with the MSTAR Sensor

    NASA Technical Reports Server (NTRS)

    Lay, Oliver P.; Dubovitsky, Serge; Peters, Robert; Burger, Johan; Ahn, Seh-Won; Steier, William H.; Fetterman, Harrold R.; Chang, Yian

    2003-01-01

    The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) 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 sub-nanometer accuracy. The sensor uses a single laser in conjunction with fast phase modulators and low frequency detectors. We describe the design of the system - the principle of operation, the metrology source, beamlaunching optics, and signal processing - and show results for target distances up to 1 meter. We then demonstrate how the system can be scaled to kilometer-scale distances.

  2. Predation risk increases dispersal distance in prey

    NASA Astrophysics Data System (ADS)

    Otsuki, Hatsune; Yano, Shuichi

    2014-06-01

    Understanding the ecological factors that affect dispersal distances allows us to predict the consequences of dispersal. Although predator avoidance is an important cause of prey dispersal, its effects on dispersal distance have not been investigated. We used simple experimental setups to test dispersal distances of the ambulatory dispersing spider mite ( Tetranychus kanzawai) in the presence or absence of a predator ( Neoseiulus womersleyi). In the absence of predators, most spider mites settled in adjacent patches, whereas the majority of those dispersing in the presence of predators passed through adjacent patches and settled in distant ones. This is the first study to experimentally demonstrate that predators induce greater dispersal distance in prey.

  3. TESTING DISTANCE ESTIMATORS WITH THE FUNDAMENTAL MANIFOLD

    SciTech Connect

    Zaritsky, Dennis; Zabludoff, Ann I.; Gonzalez, Anthony H.

    2012-03-20

    We demonstrate how the Fundamental Manifold (FM) can be used to cross-calibrate distance estimators even when those 'standard candles' are not found in the same galaxy. Such an approach greatly increases the number of distance measurements that can be utilized to check for systematic distance errors and the types of estimators that can be compared. Here we compare distances obtained using Type Ia supernova (SN Ia), Cepheids, surface brightness fluctuations, the luminosity of the tip of the red giant branch, circumnuclear masers, eclipsing binaries, RR Lyrae stars, and the planetary nebulae luminosity functions. We find no significant discrepancies (differences are <2{sigma}) between distance methods, although differences at the {approx}10% level cannot yet be ruled out. The potential exists for significant refinement because the data used here are heterogeneous B-band magnitudes that will soon be supplanted by homogeneous, near-infrared magnitudes. We illustrate the use of FM distances to (1) revisit the question of the metallicity sensitivity of various estimators, confirming the dependence of SN Ia distances on host galaxy metallicity, and (2) provide an alternative calibration of H{sub 0} that replaces the classical ladder approach in the use of extragalactic distance estimators with one that utilizes data over a wide range of distances simultaneously.

  4. Effect of Storage Time of Extended-Pour and Conventional Alginate Impressions on Dimensional Accuracy of Casts

    PubMed Central

    Rohanian, Ahmad; Ommati Shabestari, Ghasem; Zeighami, Somayeh; Samadi, Mohammad Javad; Shamshiri, Ahmad Reza

    2014-01-01

    Objectives: Some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast. Materials and Methods: In this experimental in-vitro trial, a total of 90 alginate impressions were made from a Dentoform model using Hydrogum 5, Tropicalgin and Alginoplast alginates. The impressions were stored in a sealed plastic bag without a damp paper towel for 0, 24, 48, 72 and 120 hours and then poured with type III dental stone. Cross-arch (facial of 6 to facial of 6 on the opposite side) and antero-posterior (distal of right first molar to the ipsilateral central incisor) measurements were made with a digital caliper on the casts. Data were analyzed by two-way and one-way ANOVA and Tukey’s post-hoc test (P<0.05). Results: Alginate type and the pouring time significantly affected the dimensional stability of alginate impressions (both Ps<0.001). Pouring of Hydrogum 5 impressions can be delayed for up to 120 hours without significant dimensional changes. Alginoplast impressions may be poured after 72 hours, but Tropicalgin should be poured immediately and the storage time should not be more than 24 hours. Conclusion: Immediate pouring of alginate impressions provides the highest accuracy in reproducing the teeth and adjacent tissues; however, this study demonstrated that pouring may be delayed for up to five days using extended-pour (Hydrogum 5) alginates. PMID:25628695

  5. Galaxies Gather at Great Distances

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Distant Galaxy Cluster Infrared Survey Poster [figure removed for brevity, see original site] [figure removed for brevity, see original site] Bird's Eye View Mosaic Bird's Eye View Mosaic with Clusters [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] 9.1 Billion Light-Years 8.7 Billion Light-Years 8.6 Billion Light-Years

    Astronomers have discovered nearly 300 galaxy clusters and groups, including almost 100 located 8 to 10 billion light-years away, using the space-based Spitzer Space Telescope and the ground-based Mayall 4-meter telescope at Kitt Peak National Observatory in Tucson, Ariz. The new sample represents a six-fold increase in the number of known galaxy clusters and groups at such extreme distances, and will allow astronomers to systematically study massive galaxies two-thirds of the way back to the Big Bang.

    A mosaic portraying a bird's eye view of the field in which the distant clusters were found is shown at upper left. It spans a region of sky 40 times larger than that covered by the full moon as seen from Earth. Thousands of individual images from Spitzer's infrared array camera instrument were stitched together to create this mosaic. The distant clusters are marked with orange dots.

    Close-up images of three of the distant galaxy clusters are shown in the adjoining panels. The clusters appear as a concentration of red dots near the center of each image. These images reveal the galaxies as they were over 8 billion years ago, since that's how long their light took to reach Earth and Spitzer's infrared eyes.

    These pictures are false-color composites, combining ground-based optical images captured by the Mosaic-I camera on the Mayall 4-meter telescope at Kitt Peak, with infrared pictures taken by Spitzer's infrared array camera. Blue and green represent visible light at wavelengths of 0

  6. Accuracy of Gypsum Casts after Different Impression Techniques and Double Pouring

    PubMed Central

    Silva, Stephania Caroline Rodolfo; Messias, Aion Mangino; Abi-Rached, Filipe de Oliveira; de Souza, Raphael Freitas; Reis, José Maurício dos Santos Nunes

    2016-01-01

    This study evaluated the accuracy of gypsum casts after different impression techniques and double pouring. Ten patients were selected and for each one it was obtained 5 partial putty/wash impressions with vinyl polysiloxane (VPS) material from teeth #13 to #16 with partial metal stock trays. The following techniques were performed: (1) one-step; two-step relief with: (2) PVC film; (3) slow-speed tungsten carbide bur and scalpel blade, (4) small movements of the tray and (5) without relief—negative control. The impressions were disinfected with 0.5% sodium hypochlorite for 10 minutes and stored during 110 and 230 minutes for the first and second pouring, respectively, with type IV gypsum. Three intra-oral lateral photographs of each patient were taken using a tripod and a customized radiographic positioner. The images were imported into ImageJ software and the total area of the buccal surface from teeth #13 to #16 was measured. A 4.0% coefficient of variance was criterion for using these measurements as Baseline values. The casts were photographed and analyzed using the same standardization for the clinical images. The area (mm2) obtained from the difference between the measurements of each gypsum cast and the Baseline value of the respective patient were calculated and analyzed by repeated-measures two way-ANOVA and Mauchly’s Sphericity test (α = 0.05). No significant effect was observed for Impression technique (P = 0.23), Second pouring (P = 0.99) and their interaction (P = 0.25). The impression techniques and double pouring did not influence the accuracy of the gypsum casts. PMID:27736967

  7. Un accumulateur echangeur de chaleur hybride pour la gestion simultanee des energies solaire et electrique

    NASA Astrophysics Data System (ADS)

    Ait Hammou, Zouhair

    Cette etude porte sur la conception d'un accumulateur echangeur de chaleur hybride (AECH) pour la gestion simultanee des energies solaire et electrique. Un modele mathematique reposant sur les equations de conservation de la quantite d'energie est expose. Il est developpe pour tester differents materiaux de stockage, entre autres, les materiaux a changement de phase (solide/liquide) et les materiaux de stockage sensible. Un code de calcul est mis en eeuvre sur ordinateur, puis valide a l'aide des resultats analytiques et numeriques de la litterature. En parallele, un prototype experimental a echelle reduite est concu au laboratoire afin de valider le code de calcul. Des simulations sont effectuees pour etudier les effets des parametres de conception et des materiaux de stockage sur le comportement thermique de l'AECH et sur la consommation d'energie electrique. Les resultats des simulations sur quatre mois d'hiver montrent que la paraffine n-octadecane et l'acide caprique sont deux candidats souhaitables pour le stockage d'energie destine au chauffage des habitats. L'utilisation de ces deux materiaux dans l'AECH permet de reduire la consommation d'energie electrique de 32% et d'aplanir le probleme de pointe electrique puisque 90% de l'energie electrique est consommee durant les heures creuses. En plus, en adoptant un tarif preferentiel, le calcul des couts lies a la consommation d'energie electrique montre que le consommateur adoptant ce systeme beneficie d'une reduction de 50% de la facture d'electricite.

  8. SPERTI Reactor Pit Building (PER605) under construction. Poured concrete foundation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    SPERT-I Reactor Pit Building (PER-605) under construction. Poured concrete foundation will enclosure a "Pit" into which the reactor vessel will be placed. Steel framework has been erected. To left of view is instrument cell (PER-606), constructed of concrete block. Photographer: R.G. Larsen. Date: April 22, 1955. INEEL negative no. 55-1000 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  9. A new portable vibrator for plaster pouring: effect on the marginal fit at cylinder-abutment

    PubMed Central

    de ANDRADE, Pâmela Cândida Aires Ribas; LUTHI, Leonardo Flores; STANLEY, Kyle; CARDOSO, Antônio Carlos

    2012-01-01

    Objective The aim of this study was to test a new portable vibrator for plaster pouring (developed for this purpose), comparing the effect of its use on the accuracy of working cast of implant-supported restorations to the conventional vibrator. Material and methods From a master cast with 2 implants, 30 transfer moldings were made randomly and divided into three groups: Group I (GI): pouring performed in an outsourced dental laboratory with conventional plaster vibrator (10 casts), Group II (GII): pouring performed in the laboratory of the Federal University of Santa Catarina (UFSC) with conventional plaster vibrator (10 casts) and Group III (GIII): pouring performed with the portable vibrator fabricated for this study (10 casts). The position of the analogue and marginal adaptation of the infrastructure were verified by testing the single screw on the master model and on the working model. The measurement of misfit was blindly performed with a precision microscope and analyzing unit, Quadra-Check 200. The data were statistically analyzed by analysis of variance (ANOVA) and the Holm-Sidak test (α=0.05). Results Means±standard deviations were as follows: GI: 19.19±4.73 µm; GII: 21.72±5.41 µm; GIII: 13.5±2.39 µm (P<0.05), with GIII significantly lower as compared to the other groups. Conclusion Within the limitations of this study, it was concluded that a greater accuracy of working cast was achieved when a portable vibrator was used for casting molds. PMID:23138736

  10. Methodologies nouvelles pour la realisation d'essais dans la soufflerie Price-Paidoussis

    NASA Astrophysics Data System (ADS)

    Flores Salinas, Manuel

    Le present memoire en genie de la production automatisee vise a decrire le travail effectue dans la soufflerie Price-Paidoussis du laboratoire LARCASE pour trouver les methodologies experimentales et les procedures de tests, qui seront utilisees avec les modeles d'ailes actuellement au laboratoire. Les methodologies et procedures presentees ici vont permettre de preparer les tests en soufflerie du projet MDO-505 Architectures et technologies deformables pour l'amelioration des performances des ailes, qui se derouleront durant l'annee 2015. D'abord, un bref historique des souffleries subsoniques sera fait. Les differentes sections de la soufflerie Price-Paidoussis seront decrites en mettant l'emphase sur leur influence dans la qualite de l'ecoulement qui se retrouve dans la chambre d'essai. Ensuite, une introduction a la pression, a sa mesure lors de tests en soufflerie et les instruments utilises pour les tests en soufflerie au laboratoire LARCASE sera presente, en particulier le capteur piezoelectrique XCQ-062. Une attention particuliere sera portee au mode de fonctionnement, a son installation, a la mesure et a la detection des frequences et aux sources d'erreurs lorsqu'on utilise des capteurs de haute precision comme la serie XCQ-062 du fournisseur Kulite. Finalement, les procedures et les methodologies elaborees pour les tests dans la soufflerie Price-Paidoussis seront utilisees sur quatre types d'ailes differentes. L'article New methodology for wind tunnel calibration using neural networks - EGD approch portant sur une nouvelle facon de predire les caracteristiques de l'ecoulement a l'interieur de la soufflerie Price-Paidoussis se trouve dans l'annexe 2 de ce document. Cet article porte sur la creation d'un reseau de neurones multicouche et sur l'entrainement des neurones, Ensuite, une comparaison des resultats du reseau de neurones a ete fait avec des valeurs simules avec le logiciel Fluent.

  11. Accuracy of Gypsum Casts after Different Impression Techniques and Double Pouring.

    PubMed

    Silva, Stephania Caroline Rodolfo; Messias, Aion Mangino; Abi-Rached, Filipe de Oliveira; de Souza, Raphael Freitas; Reis, José Maurício Dos Santos Nunes

    2016-01-01

    This study evaluated the accuracy of gypsum casts after different impression techniques and double pouring. Ten patients were selected and for each one it was obtained 5 partial putty/wash impressions with vinyl polysiloxane (VPS) material from teeth #13 to #16 with partial metal stock trays. The following techniques were performed: (1) one-step; two-step relief with: (2) PVC film; (3) slow-speed tungsten carbide bur and scalpel blade, (4) small movements of the tray and (5) without relief-negative control. The impressions were disinfected with 0.5% sodium hypochlorite for 10 minutes and stored during 110 and 230 minutes for the first and second pouring, respectively, with type IV gypsum. Three intra-oral lateral photographs of each patient were taken using a tripod and a customized radiographic positioner. The images were imported into ImageJ software and the total area of the buccal surface from teeth #13 to #16 was measured. A 4.0% coefficient of variance was criterion for using these measurements as Baseline values. The casts were photographed and analyzed using the same standardization for the clinical images. The area (mm2) obtained from the difference between the measurements of each gypsum cast and the Baseline value of the respective patient were calculated and analyzed by repeated-measures two way-ANOVA and Mauchly's Sphericity test (α = 0.05). No significant effect was observed for Impression technique (P = 0.23), Second pouring (P = 0.99) and their interaction (P = 0.25). The impression techniques and double pouring did not influence the accuracy of the gypsum casts.

  12. Investigation of the Pour Point Depression Ability of Polyalkyl Acrylate Additives After Sonication

    NASA Astrophysics Data System (ADS)

    Volkova, G. I.; Anufriev, R. V.; Yudina, N. V.; Tchaikovskaya, O. N.

    2016-12-01

    Effect of ultrasonic treatment on the molecular parameters of polymeric additives based on polyalkyl acrylate is investigated. The viscosity, temperature, and energy characteristics of high-wax crude oil and solutions of petroleum wax in decane and aviation fuel TS-1 in the presence of initial and ultrasonified additives are determined. Results obtained indicate that the pour point depression ability of the additives is not reduced after treatment in an ultrasonic field.

  13. Contribution à la modélisation des convertisseurs statiques pour la simulation à topologie variable

    NASA Astrophysics Data System (ADS)

    Sahraoui, Omar; Gerbaud, Laurent; Normand, Olivier; Roudet, James

    1993-06-01

    This paper presents a simple and structured method of static converter modelling with variable topology, for the simulation of controlled converter-machine drives. The methodology is based on the notion of switching cells which enables a modular decomposition of converters in structures easy to be studied and henceforth called independent converter legs. These independent legs will be stored in libraries (algorithms or programs, and models) in order to be re-used for the study of other converters. Cet article propose une méthode simple et structurée pour la modélisation des convertisseurs statiques par des modèles à topologie variable, en vue de la simulation d'associations machine-convertisseur-commande complètes. Cette démarche s'appuie sur la notion de cellule de commutation pour permettre de dégager une décomposition modulaire du convertisseur en structures élémentaires, faciles à étudier, qui seront appelées bras indépendants. Ces derniers sont stockés en bibliothèque (sous forme d'algorithme ou programme, et sous forme de modèle), pour être réutilisés dans l'étude d'autres convertisseurs.

  14. Trends in distance learning: a new wave.

    PubMed

    Oliveira, J

    1988-01-01

    Distance learning has boomed in the last decade in developed as well as developing countries. Large open universities enrolling over 2 million students have been created in Asia. In the Middle East, distance learning institutions also have expanded. Small institutions and distance learning programs have taken hold in Africa, and Latin America offers an exciting array of distance learning institutions. Great Britain's Open University is fully consolidated and mature. Traditional distance learning programs, such as the University of California's Berkeley Extension Program in the US, continue to expand. A combination of reasons underlie the new interest in and growth of distance education, including, economic, pedagogical, timing and urgency, technological advances, managerial, sociopsychological. Distance education offers a good solution to a pressing problem, i.e., scarcity of resources. At current levels of investment in education, few countries in the developing world would be able to maintain their present levels of enrollments, much less improve access and quality. Distance education can offer flexible responses to different clients, different needs, and different types of students. Thus, in this regard, distance education is a perfect example of technology fit. If countries are to compete in international markets, updated education, training, and information must flow to countries' educational institutions and technological elites. In terms of technological advances, significant progress has been made in the areas of instructional design and student support systems through software design. Systems that manage complex operations now are widely available. As with other social innovation, the burden of proof continues to rest with the proponents of distance education. To improve the credibility of distance education, researchers need to address 4 major areas: student access; instructional design; student support systems; and evaluation and accreditation procedures.

  15. National Wind Distance Learning Collaborative

    SciTech Connect

    Dr. James B. Beddow

    2013-03-29

    Executive Summary The energy development assumptions identified in the Department of Energy's position paper, 20% Wind Energy by 2030, projected an exploding demand for wind energy-related workforce development. These primary assumptions drove a secondary set of assumptions that early stage wind industry workforce development and training paradigms would need to undergo significant change if the workforce needs were to be met. The current training practice and culture within the wind industry is driven by a relatively small number of experts with deep field experience and knowledge. The current training methodology is dominated by face-to-face, classroom based, instructor present training. Given these assumptions and learning paradigms, the purpose of the National Wind Distance Learning Collaborative was to determine the feasibility of developing online learning strategies and products focused on training wind technicians. The initial project scope centered on (1) identifying resources that would be needed for development of subject matter and course design/delivery strategies for industry-based (non-academic) training, and (2) development of an appropriate Learning Management System (LMS). As the project unfolded, the initial scope was expanded to include development of learning products and the addition of an academic-based training partner. The core partners included two training entities, industry-based Airstreams Renewables and academic-based Lake Area Technical Institute. A third partner, Vision Video Interactive, Inc. provided technology-based learning platforms (hardware and software). The revised scope yielded an expanded set of results beyond the initial expectation. Eight learning modules were developed for the industry-based Electrical Safety course. These modules were subsequently redesigned and repurposed for test application in an academic setting. Software and hardware developments during the project's timeframe enabled redesign providing for

  16. Distance Education in India Present and Future.

    ERIC Educational Resources Information Center

    Datt, Ruddar

    Distance education is offered by 4 universities and 34 institutes/directorates in India. All open universities have been brought under the direction of the Indira Gandhi National Open University with regard to networking and determination of grants. The networking has avoided unnecessary duplication of course preparation costs. Distance education…

  17. Audiences and Providers of Distance Education

    ERIC Educational Resources Information Center

    Nazarinia Roy, R. Roudi; Schumm, Walter R.

    2011-01-01

    As noted by Moore (2007, xxiii), the fifth section of the second edition of the "Handbook of Distance Education" focused on "some of the main consumers and suppliers of distance education programs," including elementary and secondary education, community colleges, universities, the corporate sector, continuing professional…

  18. Who Graduates from Irish Distance University Education?

    ERIC Educational Resources Information Center

    Delaney, Lorraine

    2015-01-01

    This paper outlines results from an online survey of recent distance graduates. The study, based in Dublin City University (DCU) addresses a gap in the research on this cohort of graduates. Findings indicate that distance graduates are primarily from lower socio economic backgrounds, a group largely under-represented in full-time university…

  19. Distance Learners: Connected, Mobile and Resourceful Individuals

    ERIC Educational Resources Information Center

    Andrews, Trish; Tynan, Belinda

    2012-01-01

    In recent years the student experience of higher education in general and distance education in particular has been strongly influenced by the wide scale uptake of Internet based learning approaches and an expanding distance education market, amongst many other trends. As competition within the sector increases because of access to the WWW and…

  20. Convenient Distance Education Training in Technology.

    ERIC Educational Resources Information Center

    Adamson, Gary; Blalock, Greg

    The National Association of State Directors of Special Education, through its Research Institute of Assistive and Training Technologies (RIATT@NASDSE), has developed a planned approach to professional development in the area of assistive technology using distance education. This award-winning distance education program offers convenient,…

  1. More than Fiber: Distance Education in Iowa.

    ERIC Educational Resources Information Center

    Simonson, Michael; Schlosser, Charles

    1995-01-01

    Describes distance education programs in Iowa, including the Iowa Distance Education Alliance developed through the Department of Education's Star Schools Program; the use of fiber optic technology; and the Iowa Communications Network that links colleges, universities, and secondary schools with public television. (LRW)

  2. Adding Interactivity to Web Based Distance Learning.

    ERIC Educational Resources Information Center

    Cafolla, Ralph; Knee, Richard

    Web Based Distance Learning (WBDL) is a form of distance learning based on providing instruction mainly on the World Wide Web. This paradigm has limitations, especially the lack of interactivity inherent in the Web. The purpose of this paper is to discuss some of the technologies the authors have used in their courses at Florida Atlantic…

  3. Classroom Communication Apprehension and Distance Education.

    ERIC Educational Resources Information Center

    Marshall, Rodney

    The rise of distance education classrooms in colleges and universities call for attention to the difference in communicative strategies need from a regular classroom. This study examined the concept of classroom communication apprehension (CCA) and the distance classroom. Ninety-two students from three different classes participated in this study.…

  4. Distance Synchronous Information Systems Course Delivery

    ERIC Educational Resources Information Center

    Peslak, Alan R.; Lewis, Griffith R.; Aebli, Fred

    2014-01-01

    Teaching computer information systems via distance education is a challenge for both student and faculty. Much research work has been performed on methods of teaching via distance education. Today we are faced with a variety of options for course delivery. Asynchronous delivery via online or lesson instruction still remains most common. But…

  5. Effects of Distance Learning on Learning Effectiveness

    ERIC Educational Resources Information Center

    Liu, Hong-Cheng; Yen, Jih-Rong

    2014-01-01

    The development of computers in the past two decades has resulted in the changes of education in enterprises and schools. The advance of computer hardware and platforms allow colleges generally applying distance courses to instruction that both Ministry of Education and colleges have paid attention to the development of Distance Learning. To…

  6. 47 CFR 73.808 - Distance computations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Distance computations. 73.808 Section 73.808 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.808 Distance computations. For the purposes of...

  7. 47 CFR 73.808 - Distance computations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Distance computations. 73.808 Section 73.808 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.808 Distance computations. For the purposes of...

  8. Investigating Distance Education Students' Study Skills

    ERIC Educational Resources Information Center

    Poyraz, Cengiz

    2013-01-01

    Distance education, which is a planned way of teaching in which students and instructors are brought face to face in a classroom environment in several different ways by means of technology, has started to become widespread in many fields today. In distance education, students and instructors reside in different locations. Students can learn at…

  9. Perspectives on Distance Education and Social Media

    ERIC Educational Resources Information Center

    Powers, Lisa; Alhussain, Ruqaya; Averbeck, Clemens; Warner, Andre

    2012-01-01

    There is a dramatic shift in the tools that are used in today's technology-based distance education. While distance education is not new, there are new types of socially rich, mobile technologies that empower learners to be more in control of what they learn, when they learn it, and how they learn it. Students are taking more responsibility for…

  10. Distance Education at Memorial University of Newfoundland.

    ERIC Educational Resources Information Center

    Keough, Erin

    This presentation describes the distance education program at Memorial University (Newfoundland), which operates the Telemedicine Centre, including an audiographic, teleconference network that uses a combination of hardware and software to turn an MS DOS computer into an interactive long distance blackboard. Topics covered by the presentation…

  11. Visual-illusion distance paradoxes: a resolution.

    PubMed

    Parks, Theodore E

    2012-11-01

    Several illusory phenomena are susceptible to explanations that invoke size scaling, but only if the distance estimates used to compute size are allowed to contradict the estimates of distance that are consciously experienced at the same time. However, such "paradoxes" make sense within Milner and Goodale's (2006) two-stream theory of vision.

  12. Audiences and Providers of Distance Education

    ERIC Educational Resources Information Center

    Nazarinia Roy, R. Roudi; Schumm, Walter R.

    2011-01-01

    As noted by Moore (2007, xxiii), the fifth section of the second edition of the "Handbook of Distance Education" focused on "some of the main consumers and suppliers of distance education programs," including elementary and secondary education, community colleges, universities, the corporate sector, continuing professional…

  13. Globalization, Distance Education and Hegemonic Futures

    ERIC Educational Resources Information Center

    Russell, Glenn

    2007-01-01

    Consideration of the place of theory in distance education suggests that existing definitions do not adequately account for economic, cultural and historical factors. The application of the notion of "hegemonic valency" to distance education highlights the ways in which tools, technological systems and online environments operate in…

  14. NASA Langley/CNU Distance Learning Programs.

    ERIC Educational Resources Information Center

    Caton, Randall; Pinelli, Thomas E.

    NASA Langley Research Center and Christopher Newport University (CNU) provide, free to the public, distance learning programs that focus on math, science, and/or technology over a spectrum of education levels from K-adult. The effort started in 1997, and currently there are a suite of five distance-learning programs. This paper presents the major…

  15. Segmenting Michigan tourists based on distance traveled

    Treesearch

    Xiamei Xu; Tsao-Fang Yuan; Edwin Gomez; Joseph D. Fridgen

    1998-01-01

    The purpose of this study was to segment Michigan travelers into short, medium and long distance traveler groups by distance that they traveled from home to a primary destination in Michigan, and to compare travel behavior, trip characteristics and sociodemographics among these segments. Significant differences were identified in past trip experiences in Michigan,...

  16. Construal-Level Theory of Psychological Distance

    ERIC Educational Resources Information Center

    Trope, Yaacov; Liberman, Nira

    2010-01-01

    People are capable of thinking about the future, the past, remote locations, another person's perspective, and counterfactual alternatives. Without denying the uniqueness of each process, it is proposed that they constitute different forms of traversing psychological distance. Psychological distance is egocentric: Its reference point is the self…

  17. Challenges Encountered by a Distance Learning Organisation

    ERIC Educational Resources Information Center

    Malik, Sangeeta

    2012-01-01

    Distance learning as the name indicates is a learning, learner gets from distant places. In this learning system, learner and educators are separated by space & time. Lots of distance learning organizations are spreading to meet the increased demand of current & future needs of adult education. The rapid spread of these organizations doesn't mean…

  18. Assuring the Future for Distance Learning.

    ERIC Educational Resources Information Center

    Kaufman, Roger; Watkins, Ryan

    2000-01-01

    Discusses the rapid growth and expansion of distance education programs and provides a framework for defining, planning for, and achieving useful results from distance education programs today and in the future. Describes the Organizational Elements Model (OEM) that includes planning, design, development, implementation, and evaluation. (Contains…

  19. Student and Faculty Issues in Distance Education.

    ERIC Educational Resources Information Center

    Fender, David L.

    Occupational safety and health faculty and occupational safety and health professionals (i.e., the potential audience for graduate level distance education programs) were surveyed to determine the considerations for a distance education-based graduate occupational safety and health program. Findings are reported related to the demand for distance…

  20. Determinants of Malaysian Adult Learners' Distance Learning

    ERIC Educational Resources Information Center

    Ghani, Erlane K.; Said, Jamaliah; Nasir, Noraini Mohd

    2008-01-01

    This study attempts to identify the factors perceived to be important in choosing an Institution of Higher Learning (IHL) for distance learning. One thousand five hundred questionnaires were distributed to the first year students in the social sciences distance learning programs and 980 valid responses were received of Malaysian public university.…

  1. Modes of Production: Fordism and Distance Education.

    ERIC Educational Resources Information Center

    Farnes, Nick

    1993-01-01

    Analyzes the historical development of economic and educational systems and considers the relationship between industrialization and distance education. Modes of production and stages of conventional and distance education development are described, and future possibilities of mass higher and continuing education through the use of computer-based…

  2. Applying Leadership Theories to Distance Education Leadership

    ERIC Educational Resources Information Center

    Nworie, John

    2012-01-01

    The instructional delivery mode in distance education has been transitioning from the context of a physical classroom environment to a virtual learning environment or maintaining a hybrid of the two. However, most distance education programs in dual mode institutions are situated in traditional face-to-face instructional settings. Distance…

  3. The Viability of Distance Education Science Laboratories.

    ERIC Educational Resources Information Center

    Forinash, Kyle; Wisman, Raymond

    2001-01-01

    Discusses the effectiveness of offering science laboratories via distance education. Explains current delivery technologies, including computer simulations, videos, and laboratory kits sent to students; pros and cons of distance labs; the use of spreadsheets; and possibilities for new science education models. (LRW)

  4. Distance Learning: New Technology and New Potential.

    ERIC Educational Resources Information Center

    Bell, Julie Davis

    1991-01-01

    Some common questions that state legislators have about how distance learning can work in their states are explored. Distance learning, once considered strictly a rural education strategy, is now recognized to have the potential to provide solutions to some of the problems states face in delivering quality education to all students. A distance…

  5. Three Generations of Distance Education Pedagogy

    ERIC Educational Resources Information Center

    Anderson, Terry; Dron, Jon

    2011-01-01

    This paper defines and examines three generations of distance education pedagogy. Unlike earlier classifications of distance education based on the technology used, this analysis focuses on the pedagogy that defines the learning experiences encapsulated in the learning design. The three generations of cognitive-behaviourist, social constructivist,…

  6. Who's on First in Distance Education?

    ERIC Educational Resources Information Center

    Ansah, Angela O.; Neill, Pattie; Newton, Jodi

    2011-01-01

    The study sought to assist higher education administrators in investment decisions on distance education programs among its schools. The focus of the study was to determine differences in schools within public 4-year universities in the use of technology-based distance education (TBDE). Specifically, the study examined the differences with respect…

  7. Perspectives on Group Work in Distance Learning

    ERIC Educational Resources Information Center

    Hausstatter, Rune Sarromaa; Nordkvelle, Yngve Troye

    2007-01-01

    Current distance education benefits greatly from educational software that makes group work possible for students who are separated in time and space. However, some students prefer distance education because they can work on their own. This paper explores how students react to expectations on behalf of the course provider to do their assignments…

  8. A History of Distance Education in Mexico

    ERIC Educational Resources Information Center

    Castaneda, Manuel Moreno

    2005-01-01

    Research on distance education in Mexico is still in the embryonic stage, in spite of its long history. One indication is that among the lines of research defined by the Mexican Council on Educational Research, the leading organization in the field in Mexico, distance education does not even appear. Only recently, in the last few years, has an…

  9. Distance Education Report, 2011-2012

    ERIC Educational Resources Information Center

    California Community Colleges, Chancellor's Office, 2013

    2013-01-01

    This is a report on distance education in the California Community College. This is the seventh report to the California Community Colleges Board of Governors (BOG) per BOG Standing Order 409 (b) "that evaluates the effectiveness of distance education and education technology system wide and provides analysis of data demographically (by age,…

  10. A History of Distance Education in Mexico

    ERIC Educational Resources Information Center

    Castaneda, Manuel Moreno

    2005-01-01

    Research on distance education in Mexico is still in the embryonic stage, in spite of its long history. One indication is that among the lines of research defined by the Mexican Council on Educational Research, the leading organization in the field in Mexico, distance education does not even appear. Only recently, in the last few years, has an…

  11. Research on Distance Education Development in China

    ERIC Educational Resources Information Center

    Xin, Ding; Jian, Niu; Yanhui, Han

    2010-01-01

    Distance education is among the significant fields for the application of educational technology. Distance education in China has gone through three phases, namely: correspondence-based education, radio and TV-based education and online education. This paper was based on educational technology application, and the historical, dialectic and…

  12. Distance Education for People with Visual Impairments

    ERIC Educational Resources Information Center

    Liakou, Maria; Manousou, Evaggelia

    2015-01-01

    This paper studies the standards of higher Distance Education, focusing on the Hellenic Open University, for people who have visual impairments, so that it becomes fully accessible and thus helps reduce social exclusion. Specifically, it aims to study the operational context of Distance Education, the possibilities that modern technology provides…

  13. Facilities Planning for Interactive Distance Education.

    ERIC Educational Resources Information Center

    Carter, Alex

    1997-01-01

    Provides basic information relating to the different aspects of facilities planning for interactive distance education, including site selection, acoustics, lighting, environmental considerations, and electrical power. The importance of facilities planning during the developmental stages of an interactive distance education project is emphasized.…

  14. Support Groups in Distance Education. Knowledge Series.

    ERIC Educational Resources Information Center

    Robertshaw, Michael

    For most distance education (DE) systems, distance, time, and/or opportunity isolate learners from their teacher and their fellow students. To facilitate interaction, most DE systems include different types of support groups. Modern technology allows groups to interact effectively even though individuals are far apart. Technology may appear to be…

  15. Theme: Agricultural Education and Distance Education.

    ERIC Educational Resources Information Center

    Murphy, Tim H.; And Others

    1996-01-01

    Includes "The Time Is Now" (Murphy); "Technological Solution in Search of an Instructional Problem" (Willis, Touchstone); "'Principles' of Distance Education" (Peasley); "A Star Is Born!" (Swan); "Enrichment in the Classroom" (Blume, Talbert); "Practical Applications for Distance Education Technologies in Remote and Rural Areas" (Davis, Frick);…

  16. Exploring Cloud Computing for Distance Learning

    ERIC Educational Resources Information Center

    He, Wu; Cernusca, Dan; Abdous, M'hammed

    2011-01-01

    The use of distance courses in learning is growing exponentially. To better support faculty and students for teaching and learning, distance learning programs need to constantly innovate and optimize their IT infrastructures. The new IT paradigm called "cloud computing" has the potential to transform the way that IT resources are utilized and…

  17. Facilities Planning for Interactive Distance Education.

    ERIC Educational Resources Information Center

    Carter, Alex

    1997-01-01

    Provides basic information relating to the different aspects of facilities planning for interactive distance education, including site selection, acoustics, lighting, environmental considerations, and electrical power. The importance of facilities planning during the developmental stages of an interactive distance education project is emphasized.…

  18. Isolation by language and distance in Belgium.

    PubMed

    Barrai, I; Rodriguez-Larralde, A; Manni, F; Ruggiero, V; Tartari, D; Scapoli, C

    2004-01-01

    The isonymy structure of trilingual Belgium was studied using the surname distributions for 1,118,004 private telephone users. The users were distributed in 77 Flemish, 76 French, and 3 German speaking towns, selected on a geographic basis to form an approximately regular grid over Belgium. Lasker's distance was found to be considerably higher between languages than within languages. For the whole of Belgium, irrespective of language, it was highly correlated with linear geographic distance, with r = 0.721+/-0.014, which is the highest correlation observed in European countries to date. Within Belgium and within languages, the correlation was highest among the Flemish (r = 0.878 +/- 0.007), and lowest among the French (r = 0.631+/-0.020). Isolation by distance in Belgium is the highest we have found in Europe, and as high as in Switzerland where the different languages are separated by geographical barriers. This is not the case in Belgium, so that the considerable isolating power of languages emerges clearly from the present analysis. From the comparison of Lasker's distance between (9.48) and within (8.16) languages, and from its regression over geographic distance (b = 0.01206), it was possible to establish a quantitative relationship between the isolating power of languages and that of geographic distance as (9.48-8.16)/0.01206 = 109 kilometres. This transformation of language distance into an equivalent geographic distance, given here for Belgium, can be applied to any similar geo-linguistic situation.

  19. Managing Intellectual Property for Distance Learning

    ERIC Educational Resources Information Center

    Johnson, Liz

    2006-01-01

    Managing permissions for hundreds of pieces of intellectual property (IP) can be a daunting task for any course, but it is vital in distance learning courses because of legal implications specific to the online environment. In 1998, the Digital Millennium Copyright Act (DMCA)severely limited the use of copyrighted materials in distance learning.…

  20. The interutricular distance determined from external landmarks.

    PubMed

    Nowé, Vicky; Wuyts, Floris L; Hoppenbrouwers, Mieke; Van de Heyning, Paul H; De Schepper, Arthur M; Parizel, Paul M

    2003-01-01

    Knowledge of the exact distance between the utricles is important in new vestibular tests, such as the unilateral centrifugation (UC) test for the unilateral examination of the utricles. During this test, subjects are rotated at constant velocity and simultaneously laterally displaced along an interaural axis so that one labyrinth becomes aligned with the axis of rotation. When the axis of rotation crosses precisely through one labyrinth, only the opposite labyrinth is stimulated. To achieve this setup, precise knowledge of the interutricular distance is needed. The purpose of this study is to investigate the correlation between the interutricular distance (IUD), measured on T2-weighted magnetic resonance images, and specific external measures of head dimensions such as distance nasion-inion, intermastoid distance (IMD), distances between the temporomandibular joints and between the lateral margins of the orbits. Data have been collected in a series of 50 subjects (25 men and 25 women). On MR images we found a mean IUD of 7.22 cm (SD = 0.42 cm). There was a strong correlation between the IUD measured on MR images and the intermastoid distance. A linear combination of the IMD, nasion-inion distance and height of the subjects could predict the IUD very satisfactory (R = 0.85, adjusted R2=0.723). We also determined a measure of eccentricity of the vestibular labyrinths. The 95% prediction interval for the asymmetry appeared to be less than 4.3%.

  1. THE EXTRAGALACTIC DISTANCE SCALE WITHOUT CEPHEIDS. IV

    SciTech Connect

    Hislop, Lachlan; Mould, Jeremy; Schmidt, Brian; Bessell, Michael S.; Da Costa, Gary; Francis, Paul; Keller, Stefan; Tisserand, Patrick; Rapoport, Sharon; Casey, Andy E-mail: brian@mso.anu.edu.au

    2011-06-01

    The Cepheid period-luminosity relation is the primary distance indicator used in most determinations of the Hubble constant. The tip of the red giant branch (TRGB) is an alternative basis. Using the new Australian National University (ANU) SkyMapper Telescope, we calibrate the Tully-Fisher relation in the I band. We find that the TRGB and Cepheid distance scales are consistent.

  2. Diffusion of Distance Education in North Cyprus

    ERIC Educational Resources Information Center

    Isman, Aytekin; Dabaj, Fahme

    2005-01-01

    The purpose of the present paper is to explore how distance education has diffused in north Cyprus. In this paper, Rogers' diffusion theory (1995) was used to analyze the acceptance and implementation of distance education in institutions of higher learning in north Cyprus. The four main elements of the diffusion paradigm--the innovation,…

  3. Managing Intellectual Property for Distance Learning

    ERIC Educational Resources Information Center

    Johnson, Liz

    2006-01-01

    Managing permissions for hundreds of pieces of intellectual property (IP) can be a daunting task for any course, but it is vital in distance learning courses because of legal implications specific to the online environment. In 1998, the Digital Millennium Copyright Act (DMCA)severely limited the use of copyrighted materials in distance learning.…

  4. Distance Education for People with Visual Impairments

    ERIC Educational Resources Information Center

    Liakou, Maria; Manousou, Evaggelia

    2015-01-01

    This paper studies the standards of higher Distance Education, focusing on the Hellenic Open University, for people who have visual impairments, so that it becomes fully accessible and thus helps reduce social exclusion. Specifically, it aims to study the operational context of Distance Education, the possibilities that modern technology provides…

  5. New Strategy of the Distance Education

    ERIC Educational Resources Information Center

    Bunyatova, Fatma Khanim; Salamov, Gulbala

    2014-01-01

    This article is dedicated to new strategy of distance education. The article deals with the possibilities of ICT (Information and Communication Technologies) in teaching specially distance education. In the article, ICT technological tools and their methods of application in educational process are looked over; discrepancy of intellectual…

  6. Measuring Distances to Remote Galaxies and Quasars.

    ERIC Educational Resources Information Center

    McCarthy, Patrick J.

    1988-01-01

    Describes the use of spectroscopy and the redshift to measure how far an object is by measuring how fast it is receding from earth. Lists the most distant quasars yet found. Tables include "Redshift vs. Distance" and "Distances to Celestial Objects for Various Cosmologies." (CW)

  7. Research Projects Scheme in Distance Education.

    ERIC Educational Resources Information Center

    Rausaria, R. R., Ed.; Bhushan, Bharat, Ed.; Lele, N. A., Ed.

    This guidebook is intended to help researchers apply for funds for research projects in distance education through the Distance Education Council of Indira Gandhi National Open University (India). The stated intent of this guidebook is to encourage system-based research; to promote in-depth studies to evaluation programs, their impact, and their…

  8. Binding Principle for Long-Distance Anaphors.

    ERIC Educational Resources Information Center

    Choi, Dong-Ik

    1997-01-01

    An analysis of long-distance anaphora, a binding phenomenon in which reflexives find their antecedents outside their local domain, is presented, using data from English, Chinese, Japanese, Korean, Russian, Icelandic, and Italian. It is found that no approach deals with long-distance anaphors exclusively and elegantly. The binding domain…

  9. Distance Education: Pros, Cons, and the Future.

    ERIC Educational Resources Information Center

    Li, Hongmei

    This paper reviews recent publications on distance education and explores its promise and potential from the student's perspective, the faculty's perspective and the administrator's perspective. Findings indicate that only the self-motivated and self-disciplined students are most likely to succeed in distance education. Although the majority of…

  10. Engineering Undergraduate Distance Learning Programs: An Assessment.

    ERIC Educational Resources Information Center

    Kunnath, Maria Lorna; Eaglin, Ronald

    Distance education reverses the traditional way of providing education to the learning community. Instead of students coming to the university to get that needed education, the university comes to the student. This research/survey of undergraduate engineering distance learning universities was conducted utilizing traditional and virtual sources of…

  11. Effects of Distance Learning on Learning Effectiveness

    ERIC Educational Resources Information Center

    Liu, Hong-Cheng; Yen, Jih-Rong

    2014-01-01

    The development of computers in the past two decades has resulted in the changes of education in enterprises and schools. The advance of computer hardware and platforms allow colleges generally applying distance courses to instruction that both Ministry of Education and colleges have paid attention to the development of Distance Learning. To…

  12. Spell Sequences, State Proximities, and Distance Metrics

    ERIC Educational Resources Information Center

    Elzinga, Cees H.; Studer, Matthias

    2015-01-01

    Because optimal matching (OM) distance is not very sensitive to differences in the order of states, we introduce a subsequence-based distance measure that can be adapted to subsequence length, to subsequence duration, and to soft-matching of states. Using a simulation technique developed by Studer, we investigate the sensitivity, relative to OM,…

  13. More than Fiber: Distance Education in Iowa.

    ERIC Educational Resources Information Center

    Simonson, Michael; Schlosser, Charles

    1995-01-01

    Describes distance education programs in Iowa, including the Iowa Distance Education Alliance developed through the Department of Education's Star Schools Program; the use of fiber optic technology; and the Iowa Communications Network that links colleges, universities, and secondary schools with public television. (LRW)

  14. Language Distance Learning for the Digital Generation

    ERIC Educational Resources Information Center

    Duran-Cerda, Dolores

    2010-01-01

    The purpose of this article was to shed light on the potential of distance learning to overcome challenges in distance, space, time, and human and economic resources that limit access to language learning opportunities in cultural, literary, historical, geographical, and cross-cultural frames. Language and literature educators collectively have…

  15. Measuring Distances to Remote Galaxies and Quasars.

    ERIC Educational Resources Information Center

    McCarthy, Patrick J.

    1988-01-01

    Describes the use of spectroscopy and the redshift to measure how far an object is by measuring how fast it is receding from earth. Lists the most distant quasars yet found. Tables include "Redshift vs. Distance" and "Distances to Celestial Objects for Various Cosmologies." (CW)

  16. Research on Distance Education Development in China

    ERIC Educational Resources Information Center

    Xin, Ding; Jian, Niu; Yanhui, Han

    2010-01-01

    Distance education is among the significant fields for the application of educational technology. Distance education in China has gone through three phases, namely: correspondence-based education, radio and TV-based education and online education. This paper was based on educational technology application, and the historical, dialectic and…

  17. Build Optional Digital Textbooks for Distance Learners

    ERIC Educational Resources Information Center

    Ruo, Du; Xiaotang, Yang

    2013-01-01

    E-books seem to be a trend and an excellent solution for mobile learning lately, but what kinds of e-books are good fit for distance learners' needs? For the purpose of offering open, more appropriate, better in quality, more convenient and flexible learning materials for distance learners. From 2011, through an experimental study on the basis of…

  18. 47 CFR 73.808 - Distance computations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Distance computations. 73.808 Section 73.808 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.808 Distance computations. For the purposes of...

  19. 47 CFR 73.808 - Distance computations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Distance computations. 73.808 Section 73.808 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.808 Distance computations. For the purposes of...

  20. 47 CFR 73.808 - Distance computations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Distance computations. 73.808 Section 73.808 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.808 Distance computations. For the purposes of...

  1. Iowa Distance Education Alliance. Final Evaluation Report.

    ERIC Educational Resources Information Center

    Sorensen, Chris; Sweeney, Jan

    This document describes the accomplishments of the Iowa Distance Education Alliance (IDEA). The Iowa Distance Education Alliance (IDEA) is a partnership involving educational institutions across Iowa that received funding from the federal Star Schools Program to demonstrate the use of the Iowa Communication Network's (ICN) fiber optic technology…

  2. Theme: Agricultural Education and Distance Education.

    ERIC Educational Resources Information Center

    Murphy, Tim H.; And Others

    1996-01-01

    Includes "The Time Is Now" (Murphy); "Technological Solution in Search of an Instructional Problem" (Willis, Touchstone); "'Principles' of Distance Education" (Peasley); "A Star Is Born!" (Swan); "Enrichment in the Classroom" (Blume, Talbert); "Practical Applications for Distance Education Technologies in Remote and Rural Areas" (Davis, Frick);…

  3. Distance Learning and Intellectual Property Protection.

    ERIC Educational Resources Information Center

    Pisacreta, Edward A.

    1993-01-01

    Examines laws governing intellectual property that affect distance education. Topics addressed include copyright law, particularly the concept of fair use; traditional applications of copyright law in education, including photocopying and the Classroom Guidelines; and distance learning and copyright law, including works transmitted via…

  4. Building Learning Communities with Distance Learning Instruction

    ERIC Educational Resources Information Center

    Wilson, Janell D.; Cordry, Sheila A.; King, Nina

    2004-01-01

    With the expansion and continued development of computer technology, a new world of educational opportunities is opening up via on-line distance learning. While distance learning is far from new, recent years have seen an explosion in the mechanisms and tools available for its implementation and support (Spodnick, 1996). It is also reported that…

  5. Collaboration in Distance Education. International Case Studies.

    ERIC Educational Resources Information Center

    Moran, Louise, Ed.; Mugridge, Ian, Ed.

    This book contains nine case studies of collaboration in distance education. The case studies focus on such aspects of collaboration in distance education as the following: roles of individual institutional partners; importance of personal relationships; benefits of collaboration to individual partners; conflicts between collaboration and…

  6. Distance Learning for Mobile Internet Users

    ERIC Educational Resources Information Center

    Necat, Beran

    2007-01-01

    This paper provides an overview on the current state of art in the field of Distance learning for mobile users. It mentions a large range of technologies, services and approaches that may be used to bring distance learning to mobile internet users. These technologies are supposed to considerably increase innovative e-learning solutions for the…

  7. Getting Started as Distance Learning Librarian

    ERIC Educational Resources Information Center

    Wyss, Paul Alan

    2008-01-01

    Many colleges and universities are developing distance education options for their current and future students. Library support is vital to the success of this clientele. Academic libraries that do not have Distance Learning Librarians will have to create these types of positions. This article illustrates the experience of one librarian in…

  8. Who Graduates from Irish Distance University Education?

    ERIC Educational Resources Information Center

    Delaney, Lorraine

    2015-01-01

    This paper outlines results from an online survey of recent distance graduates. The study, based in Dublin City University (DCU) addresses a gap in the research on this cohort of graduates. Findings indicate that distance graduates are primarily from lower socio economic backgrounds, a group largely under-represented in full-time university…

  9. Exploring Cloud Computing for Distance Learning

    ERIC Educational Resources Information Center

    He, Wu; Cernusca, Dan; Abdous, M'hammed

    2011-01-01

    The use of distance courses in learning is growing exponentially. To better support faculty and students for teaching and learning, distance learning programs need to constantly innovate and optimize their IT infrastructures. The new IT paradigm called "cloud computing" has the potential to transform the way that IT resources are utilized and…

  10. Research into Distance Education = Fernlehre und Fernlehrforschung.

    ERIC Educational Resources Information Center

    Holmberg, Borje, Ed.; Ortner, Gerhard E., Ed.

    The papers (from a symposium held at the Fern Universitat) included in this collection focus on distance education in theory and practice. Contributions are written in English or in German, with summaries available for each in the language not used for the paper concerned. Contributions are: (1) "Distance Education as Communication: The…

  11. Construal-Level Theory of Psychological Distance

    ERIC Educational Resources Information Center

    Trope, Yaacov; Liberman, Nira

    2010-01-01

    People are capable of thinking about the future, the past, remote locations, another person's perspective, and counterfactual alternatives. Without denying the uniqueness of each process, it is proposed that they constitute different forms of traversing psychological distance. Psychological distance is egocentric: Its reference point is the self…

  12. NSHE 2009-2010 Distance Education Report

    ERIC Educational Resources Information Center

    Nevada System of Higher Education, 2010

    2010-01-01

    This report focuses on distance education within the Nevada System of Higher Education (NSHE) for the 2009-10 academic year and provides documentation of the substantial growth of distance education within all colleges and universities. From this report, one gains an understanding of significant developments throughout the state and at each…

  13. Modelisation frequentielle de la permittivite du beton pour le controle non destructif par georadar

    NASA Astrophysics Data System (ADS)

    Bourdi, Taoufik

    Le georadar (Ground Penetrating Radar (GPR)) constitue une technique de controle non destructif (CND) interessante pour la mesure des epaisseurs des dalles de beton et la caracterisation des fractures, en raison de ses caracteristiques de resolution et de profondeur de penetration. Les equipements georadar sont de plus en plus faciles a utiliser et les logiciels d'interpretation sont en train de devenir plus aisement accessibles. Cependant, il est ressorti dans plusieurs conferences et ateliers sur l'application du georadar en genie civil qu'il fallait poursuivre les recherches, en particulier sur la modelisation et les techniques de mesure des proprietes electriques du beton. En obtenant de meilleures informations sur les proprietes electriques du beton aux frequences du georadar, l'instrumentation et les techniques d'interpretation pourraient etre perfectionnees plus efficacement. Le modele de Jonscher est un modele qui a montre son efficacite dans le domaine geophysique. Pour la premiere fois, son utilisation dans le domaine genie civil est presentee. Dans un premier temps, nous avons valide l'application du modele de Jonscher pour la caracterisation de la permittivite dielectrique du beton. Les resultats ont montre clairement que ce modele est capable de reproduire fidelement la variation de la permittivite de differents types de beton sur la bande de frequence georadar (100 MHz-2 GHz). Dans un deuxieme temps, nous avons montre l'interet du modele de Jonscher en le comparant a d'autres modeles (Debye et Debye-etendu) deja utilises dans le domaine genie civil. Nous avons montre aussi comment le modele de Jonscher peut presenter une aide a la prediction de l'efficacite de blindage et a l'interpretation des ondes de la technique GPR. Il a ete determine que le modele de Jonscher permet de donner une bonne presentation de la variation de la permittivite du beton dans la gamme de frequence georadar consideree. De plus, cette modelisation est valable pour differents

  14. Instrumentation pour la spectroscopie laser sur faisceau d'ions rapides

    NASA Astrophysics Data System (ADS)

    Bazin, Marc

    Devant l'emergence des technologies exploitant l'infiniment petit, la spectroscopie atomique et moleculaire devient de plus en plus incontournable pour comprendre precisement les mecanismes quantiques impliques dans l'interaction des molecules. C'est le cas notamment de la nanotechnologie, de la dynamique reactionnelle des gaz a effet de serre ou simplement de l'identification des molecules constituant certains objets de l'astrophysique. Bien qu'un travail considerable soit deja accompli pour comprendre la dissociation ou la formation des molecules simples, il reste a vaincre la complexite des mecanismes impliques lorsque les molecules possedent plus de trois noyaux. Parmi les rares techniques de spectroscopie a tres haute resolution (jusqu'a la structure hyperfine), la spectroscopie laser sur faisceaux d'ions rapides est une methode experimentale eprouvee depuis trois decennies environ. Cette methode spectroscopique fournit des resultats comptant parmi les meilleurs pour obtenir des constantes moleculaires precises et permettre la reduction du spectre moleculaire. Une particularite remarquable de notre instrument est la possibilite d'enregistrer le signal de fragmentation moleculaire par laser via les etats de predissociation de la molecule etudiee. Notre contribution a ete d'ameliorer et de moderniser l'equipement existant. Nous avons augmente la resolution spectrale de notre instrument. Nous avons atteint notre principal objectif, a savoir, la possibilite d'acquerir des spectres selon deux modes : par detection du signal synchronisee sur le faisceau laser module en frequence ou par detection du signal directement par comptage. Cette derniere methode est une premiere sur ce type d'instrument et son principal interet a ete d'obtenir une meilleure mesure de l'elargissement de raie. Nous sommes parvenus a mettre clairement en evidence l'elargissement de raie avec la puissance laser en utilisant la methode de detection par comptage direct. La fluorescence induite par

  15. Elaboration de nouvelles approches micromecaniques pour l'optimisation des performances mecaniques des materiaux heterogenes

    NASA Astrophysics Data System (ADS)

    Aboutajeddine, Ahmed

    Les modeles micromecaniques de transition d'echelles qui permettent de determiner les proprietes effectives des materiaux heterogenes a partir de la microstructure sont consideres dans ce travail. L'objectif est la prise en compte de la presence d'une interphase entre la matrice et le renforcement dans les modeles micromecaniques classiques, de meme que la reconsideration des approximations de base de ces modeles, afin de traiter les materiaux multiphasiques. Un nouveau modele micromecanique est alors propose pour tenir compte de la presence d'une interphase elastique mince lors de la determination des proprietes effectives. Ce modele a ete construit grace a l'apport de l'equation integrale, des operateurs interfaciaux de Hill et de la methode de Mori-Tanaka. Les expressions obtenues pour les modules globaux et les champs dans l'enrobage sont de nature analytique. L'approximation de base de ce modele est amelioree par la suite dans un nouveau modele qui s'interesse aux inclusions enrobees avec un enrobage mince ou epais. La resolution utilisee s'appuie sur une double homogeneisation realisee au niveau de l'inclusion enrobee et du materiau. Cette nouvelle demarche, permettra d'apprehender completement les implications des approximations de la modelisation. Les resultats obtenus sont exploites par la suite dans la solution de l'assemblage de Hashin. Ainsi, plusieurs modeles micromecaniques classiques d'origines differentes se voient unifier et rattacher, dans ce travail, a la representation geometrique de Hashin. En plus de pouvoir apprecier completement la pertinence de l'approximation de chaque modele dans cette vision unique, l'extension correcte de ces modeles aux materiaux multiphasiques est rendue possible. Plusieurs modeles analytiques et explicites sont alors proposee suivant des solutions de differents ordres de l'assemblage de Hashin. L'un des modeles explicite apparait comme une correction directe du modele de Mori-Tanaka, dans les cas ou celui ci echoue a

  16. Distance education and self-study

    NASA Astrophysics Data System (ADS)

    Jones, Barrie W.

    It is not my purpose to specify how distance education and self-study should be used to teach astronomy in developing countries - my teaching experience in such countries, though not negligible, is rather too limited for that. I do, however, have extensive experience of distance education in the U.K., and therefore my purpose in this article is to display the characteristics of distance education, and of self-study, in order to promote debate about how they can best be used in astronomy educatin in the developing world. Distance education has the potential to overcome - a shortage of astronomy teachers - a shortage of non-human resources - difficulties that students face in attending a campus. Additionally, distance education materials can be used to increase self-study on campus, and hence overcome the first two of these problems.

  17. Minimum-distance Problems in Protocol Design

    NASA Technical Reports Server (NTRS)

    Posner, E. C.; Reichstein, Z.

    1984-01-01

    Codes for use in personal computer file transfer as control characters, when only upper-case ASCII can be used to avoid dependence on unique machine features and promote portability. If ten control functions are needed, a number used in at least one protocol, a subset of ten upper-case ASCII characters with good distance properties is sought. The control functions form themselves naturally into three groups, one of two functions (ACK and NAK) and two of four. The aim is to make ACK and NAK as antipodal as possible (distance 6), make the distances within each of the other groups as large as possible (4), and otherwise have as few 2's in the distance table as possible, recognizing that only even distances can occur. The minimum and an assignment that attains the minimum are found. The code is essentially unique. The analogous problem for two groups of three control functions and one group of four is also solved.

  18. Construal-Level Theory of Psychological Distance

    PubMed Central

    Trope, Yaacov; Liberman, Nira

    2011-01-01

    People are capable of thinking about the future, the past, remote locations, another person’s perspective, and counterfactual alternatives. Without denying the uniqueness of each process, it is proposed that they constitute different forms of traversing psychological distance. Psychological distance is egocentric: Its reference point is the self in the here and now, and the different ways in which an object might be removed from that point—in time, in space, in social distance, and in hypotheticality—constitute different distance dimensions. Transcending the self in the here and now entails mental construal, and the farther removed an object is from direct experience, the higher (more abstract) the level of construal of that object. Supporting this analysis, research shows (a) that the various distances are cognitively related to each other, (b) that they similarly influence and are influenced by level of mental construal, and (c) that they similarly affect prediction, preference, and action. PMID:20438233

  19. The ideal subject distance for passport pictures.

    PubMed

    Verhoff, Marcel A; Witzel, Carsten; Kreutz, Kerstin; Ramsthaler, Frank

    2008-07-04

    In an age of global combat against terrorism, the recognition and identification of people on document images is of increasing significance. Experiments and calculations have shown that the camera-to-subject distance - not the focal length of the lens - can have a significant effect on facial proportions. Modern passport pictures should be able to function as a reference image for automatic and manual picture comparisons. This requires a defined subject distance. It is completely unclear which subject distance, in the taking of passport photographs, is ideal for the recognition of the actual person. We show here that the camera-to-subject distance that is perceived as ideal is dependent on the face being photographed, even if the distance of 2m was most frequently preferred. So far the problem of the ideal camera-to-subject distance for faces has only been approached through technical calculations. We have, for the first time, answered this question experimentally with a double-blind experiment. Even if there is apparently no ideal camera-to-subject distance valid for every face, 2m can be proposed as ideal for the taking of passport pictures. The first step would actually be the determination of a camera-to-subject distance for the taking of passport pictures within the standards. From an anthropological point of view it would be interesting to find out which facial features allow the preference of a shorter camera-to-subject distance and which allow the preference of a longer camera-to-subject distance.

  20. On Properties of the Generalized Wasserstein Distance

    NASA Astrophysics Data System (ADS)

    Piccoli, Benedetto; Rossi, Francesco

    2016-12-01

    The Wasserstein distances W p ( p {≥q} 1), defined in terms of a solution to the Monge-Kantorovich problem, are known to be a useful tool to investigate transport equations. In particular, the Benamou-Brenier formula characterizes the square of the Wasserstein distance W 2 as the infimum of the kinetic energy, or action functional, of all vector fields transporting one measure to the other. Another important property of the Wasserstein distances is the Kantorovich-Rubinstein duality, stating the equality between the distance W 1( μ, ν) of two probability measures μ, ν and the supremum of the integrals in d( μ - ν) of Lipschitz continuous functions with Lipschitz constant bounded by one. An intrinsic limitation of Wasserstein distances is the fact that they are defined only between measures having the same mass. To overcome such a limitation, we recently introduced the generalized Wasserstein distances {W_p^{a,b}}, defined in terms of both the classical Wasserstein distance W p and the total variation (or L 1) distance, see (Piccoli and Rossi in Archive for Rational Mechanics and Analysis 211(1):335-358, 2014). Here p plays the same role as for the classic Wasserstein distance, while a and b are weights for the transport and the total variation term. In this paper we prove two important properties of the generalized Wasserstein distances: (1) a generalized Benamou-Brenier formula providing the equality between {W_2^{a,b}} and the supremum of an action functional, which includes a transport term (kinetic energy) and a source term; (2) a duality à la Kantorovich-Rubinstein establishing the equality between {W_1^{1,1}} and the flat metric.