WorldWideScience

Sample records for motivated curve smoothers

  1. A Bioequivalence Test by the Direct Comparison of Concentration-versus-Time Curves Using Local Polynomial Smoothers

    Directory of Open Access Journals (Sweden)

    Suyan Tian

    2016-01-01

    Full Text Available In order to test if two chemically or pharmaceutically equivalent products have the same efficacy and/or toxicity, a bioequivalence (BE study is conducted. The 80%/125% rule is the most commonly used criteria for BE and states that BE cannot be claimed unless the 90% CIs for the ratio of selected pharmacokinetics (PK parameters of the tested to the reference drug are within 0.8 to 1.25. Considering that estimates of these PK parameters are derived from the concentration-versus-time curves, a direct comparison between these curves motivates an alternative and more flexible approach to test BE. Here, we propose to frame the BE test in terms of an equivalence of concentration-versus-time curves which are constructed using local polynomial smoother (LPS. A metric is presented to quantify the distance between the curves and its 90% CIs are calculated via bootstrapping. Then, we applied the proposed procedures to data from an animal study and found that BE between a generic drug and its brand name cannot be concluded, which was consistent with the results by applying the 80%/125% rule. However, the proposed procedure has the advantage of testing only on a single metric, instead of all PK parameters.

  2. A Bioequivalence Test by the Direct Comparison of Concentration-versus-Time Curves Using Local Polynomial Smoothers

    Science.gov (United States)

    Chang, Howard H.; Orange, Dana

    2016-01-01

    In order to test if two chemically or pharmaceutically equivalent products have the same efficacy and/or toxicity, a bioequivalence (BE) study is conducted. The 80%/125% rule is the most commonly used criteria for BE and states that BE cannot be claimed unless the 90% CIs for the ratio of selected pharmacokinetics (PK) parameters of the tested to the reference drug are within 0.8 to 1.25. Considering that estimates of these PK parameters are derived from the concentration-versus-time curves, a direct comparison between these curves motivates an alternative and more flexible approach to test BE. Here, we propose to frame the BE test in terms of an equivalence of concentration-versus-time curves which are constructed using local polynomial smoother (LPS). A metric is presented to quantify the distance between the curves and its 90% CIs are calculated via bootstrapping. Then, we applied the proposed procedures to data from an animal study and found that BE between a generic drug and its brand name cannot be concluded, which was consistent with the results by applying the 80%/125% rule. However, the proposed procedure has the advantage of testing only on a single metric, instead of all PK parameters. PMID:28050196

  3. Adaptive Algebraic Smoothers

    Energy Technology Data Exchange (ETDEWEB)

    Philip, Bobby [ORNL; Chartier, Dr Timothy [Davidson College

    2012-01-01

    methods based on Local Sensitivity Analysis (LSA). The method can be used in the context of geometric and algebraic multigrid methods for constructing smoothers, and in the context of Krylov methods for constructing block preconditioners. It is suitable for both constant and variable coecient problems. Furthermore, the method can be applied to systems arising from both scalar and coupled system partial differential equations (PDEs), as well as linear systems that do not arise from PDEs. The simplicity of the method will allow it to be easily incorporated into existing multigrid and Krylov solvers while providing a powerful tool for adaptively constructing methods tuned to a problem.

  4. A smoother pebble mathematical explorations

    CERN Document Server

    Benson, Donald C

    2003-01-01

    Introduction. I. BRIDGING THE GAP. 1. The Ancient Fractions. 2. Greek Gifts. 3. The Music of the Ratios. II. THE SHAPE OF THINGS. 4. Tubeland. 5. The Calculating Eye. III. THE GREAT ART. 6. Algebra Rules. 7. The Root of the Problem. 8. Symmetry Without Fear. 9. The Magic Mirror. IV. A SMOOTHER PEBBLE. 10. On the Shoulders of Giants. 11. Six-Minute Calculus. 12. Roller-Coaster Science. Glossary. References. Index

  5. The Motive of the Moduli Stack of -Bundles over the Universal Curve

    Indian Academy of Sciences (India)

    Donu Arapura; Ajneet Dhillon

    2008-08-01

    We define relative motives in the sense of André. After associating a complex in the derived category of motives to an algebraic stack we study this complex in the case of the moduli of -bundles varying over the moduli of curves.

  6. A Localized Ensemble Kalman Smoother

    Science.gov (United States)

    Butala, Mark D.

    2012-01-01

    Numerous geophysical inverse problems prove difficult because the available measurements are indirectly related to the underlying unknown dynamic state and the physics governing the system may involve imperfect models or unobserved parameters. Data assimilation addresses these difficulties by combining the measurements and physical knowledge. The main challenge in such problems usually involves their high dimensionality and the standard statistical methods prove computationally intractable. This paper develops and addresses the theoretical convergence of a new high-dimensional Monte-Carlo approach called the localized ensemble Kalman smoother.

  7. Effect of intrinsic motivation on affective responses during and after exercise: latent curve model analysis.

    Science.gov (United States)

    Shin, Myoungjin; Kim, Inwoo; Kwon, Sungho

    2014-12-01

    Understanding the relationship between affect and exercise is helpful in predicting human behavior with respect to exercise participation. The goals of the present study were to investigate individual differences in affective response during and after exercise and to identify the role of intrinsic motivation in affective changes. 30 active male college students (M age = 21.4 yr.) who regularly participated in sports activities volunteered to answer a questionnaire measuring intrinsic motivation toward running activities and performed a 20-min. straight running protocol at heavy intensity (about 70% of VO2max). Participants' affective responses were measured every 5 min. from the beginning of the run to 10 min. after completing the run. Latent curve model analysis indicated that individuals experienced different changes in affective state during exercise, moderated by intrinsic motivation. Higher intrinsic motivation was associated with more positive affect during exercise. There were no significant individual differences in the positive tendency of the participants' affective responses after exercise over time. Intrinsic motivation seems to facilitate positive feelings during exercise and encourages participation in exercise.

  8. Recursive bias estimation for high dimensional smoothers

    Energy Technology Data Exchange (ETDEWEB)

    Hengartner, Nicolas W [Los Alamos National Laboratory; Matzner-lober, Eric [UHB, FRANCE; Cornillon, Pierre - Andre [INRA

    2008-01-01

    In multivariate nonparametric analysis, sparseness of the covariates also called curse of dimensionality, forces one to use large smoothing parameters. This leads to biased smoothers. Instead of focusing on optimally selecting the smoothing parameter, we fix it to some reasonably large value to ensure an over-smoothing of the data. The resulting smoother has a small variance but a substantial bias. In this paper, we propose to iteratively correct the bias initial estimator by an estimate of the latter obtained by smoothing the residuals. We examine in detail the convergence of the iterated procedure for classical smoothers and relate our procedure to L{sub 2}-Boosting. We apply our method to simulated and real data and show that our method compares favorably with existing procedures.

  9. 4DVAR by ensemble Kalman smoother

    CERN Document Server

    Mandel, Jan; Gratton, Serge

    2013-01-01

    We propose to use the ensemble Kalman smoother (EnKS) as linear least squares solver in the Gauss-Newton method for the large nonlinear least squares in incremental 4DVAR. The ensemble approach is naturally parallel over the ensemble members and no tangent or adjoint operators are needed. Further, adding a regularization term results in replacing the Gauss-Newton method, which may diverge, by^M the Levenberg-Marquardt method, which is known to be convergent. The regularization is implemented efficiently as an additional observation in the EnKS.

  10. A Latent Curve Model of Parental Motivational Practices and Developmental Decline in Math and Science Academic Intrinsic Motivation

    Science.gov (United States)

    Gottfried, Adele Eskeles; Marcoulides, George A.; Gottfried, Allen W.; Oliver, Pamella H.

    2009-01-01

    A longitudinal approach was used to examine the effects of parental task-intrinsic and task-extrinsic motivational practices on academic intrinsic motivation in the subject areas of math and science. Parental task-intrinsic practices comprise encouragement of children's pleasure and engagement in the learning process, whereas task-extrinsic…

  11. A Latent Curve Model of Parental Motivational Practices and Developmental Decline in Math and Science Academic Intrinsic Motivation

    Science.gov (United States)

    Gottfried, Adele Eskeles; Marcoulides, George A.; Gottfried, Allen W.; Oliver, Pamella H.

    2009-01-01

    A longitudinal approach was used to examine the effects of parental task-intrinsic and task-extrinsic motivational practices on academic intrinsic motivation in the subject areas of math and science. Parental task-intrinsic practices comprise encouragement of children's pleasure and engagement in the learning process, whereas task-extrinsic…

  12. An Investigation of Early Parental Motivational Strategies on Mathematics Achievement by Ethnicity: A Latent Curve Model Approach

    Science.gov (United States)

    McDonald, Stefanie R.; Ing, Marsha; Marcoulides, George A.

    2010-01-01

    This study examined the developmental effects of early parental intrinsic and extrinsic motivational strategies on mathematics achievement scores obtained from White students compared to underrepresented minority students. A latent growth curve model was fit to data from the Longitudinal Study of American Youth (LSAY) with mathematics achievement…

  13. Robust and Trend-following Kalman Smoothers using Student's t

    CERN Document Server

    Aravkin, Aleksandr Y; Pillonetto, Gianluigi

    2011-01-01

    We propose two nonlinear Kalman smoothers that rely on Student's t distributions. The T-Robust smoother finds the maximum a posteriori likelihood (MAP) solution for Gaussian process noise and Student's t observation noise, and is extremely robust against outliers, outperforming the recently proposed l1-Laplace smoother in extreme situations (e.g. 50% or more outliers). The second estimator, which we call the T-Trend smoother, is able to follow sudden changes in the process model, and is derived as a MAP solver for a model with Student's t-process noise and Gaussian observation noise. We design specialized methods to solve both problems which exploit the special structure of the Student's t-distribution, and provide a convergence theory. Both smoothers can be implemented with only minor modifications to an existing L2 smoother implementation. Numerical results for linear and nonlinear models illustrating both robust and fast tracking applications are presented.

  14. Teacher-Student Interpersonal Relationships Do Change and Affect Academic Motivation: A Multilevel Growth Curve Modelling

    Science.gov (United States)

    Maulana, Ridwan; Opdenakker, Marie-Christine; Bosker, Roel

    2014-01-01

    Background: Research has shown that the teacher-student interpersonal relationship (TSIR) is important for student motivation. Although TSIR has received a growing interest, there are only few studies that focus on changes and links between TSIR and student academic motivation in a longitudinal fashion in non-Western contexts. Aims: This study…

  15. Efficient relaxed-Jacobi smoothers for multigrid on parallel computers

    Science.gov (United States)

    Yang, Xiang; Mittal, Rajat

    2017-03-01

    In this Technical Note, we present a family of Jacobi-based multigrid smoothers suitable for the solution of discretized elliptic equations. These smoothers are based on the idea of scheduled-relaxation Jacobi proposed recently by Yang & Mittal (2014) [18] and employ two or three successive relaxed Jacobi iterations with relaxation factors derived so as to maximize the smoothing property of these iterations. The performance of these new smoothers measured in terms of convergence acceleration and computational workload, is assessed for multi-domain implementations typical of parallelized solvers, and compared to the lexicographic point Gauss-Seidel smoother. The tests include the geometric multigrid method on structured grids as well as the algebraic grid method on unstructured grids. The tests demonstrate that unlike Gauss-Seidel, the convergence of these Jacobi-based smoothers is unaffected by domain decomposition, and furthermore, they outperform the lexicographic Gauss-Seidel by factors that increase with domain partition count.

  16. An improved Kalman Smoother for atmospheric inversions

    Directory of Open Access Journals (Sweden)

    L. M. P. Bruhwiler

    2005-01-01

    Full Text Available We explore the use of a fixed-lag Kalman smoother for sequential estimation of atmospheric carbon dioxide fluxes. This technique takes advantage of the fact that most of the information about the spatial distribution of sources and sinks is observable within a few months to half of a year of emission. After this period, the spatial structure of sources is diluted by transport and cannot significantly constrain flux estimates. We therefore describe an estimation technique that steps through the observations sequentially, using only the subset of observations and modeled transport fields that most strongly constrain the fluxes at a particular time step. Estimates of each set of fluxes are sequentially updated multiple times, using measurements taken at different times, and the estimates and their uncertainties are shown to quickly converge. Final flux estimates are incorporated into the background state of CO2 and transported forward in time, and the final flux uncertainties and covariances are taken into account when estimating the covariances of the fluxes still being estimated. The computational demands of this technique are greatly reduced in comparison to the standard Bayesian synthesis technique where all observations are used at once with transport fields spanning the entire period of the observations. It therefore becomes possible to solve larger inverse problems with more observations and for fluxes discretized at finer spatial scales. We also discuss the differences between running the inversion simultaneously with the transport model and running it entirely off-line with pre-calculated transport fields. We find that the latter can be done with minimal error if time series of transport fields of adequate length are pre-calculated.

  17. An improved Kalman Smoother for atmospheric inversions

    Directory of Open Access Journals (Sweden)

    L. M. P. Bruhwiler

    2005-03-01

    Full Text Available We explore the use of a fixed-lag Kalman smoother for sequential estimation of atmospheric carbon dioxide fluxes. This technique takes advantage of the fact that most of the information about the spatial distribution of sources and sinks is observable within a 5 few months to half of a year of emission. After this period, the spatial structure of sources is diluted by transport and cannot significantly constrain flux estimates. We therefore describe an estimation technique that steps through the observations sequentially, using only the subset of observations and modeled transport fields that most strongly constrain the fluxes at a particular time step. Estimates of each set of fluxes 10 are sequentially updated multiple times, using measurements taken at different times, and the estimates and their uncertainties are shown to quickly converge. Final flux estimates are incorporated into the background state of CO2 and transported forward in time, and the final flux uncertainties and covariances are taken into account when estimating the covariances of the fluxes still being estimated. The computational demands 15 of this technique are greatly reduced in comparison to the standard Bayesian synthesis technique where all observations are used at once with transport fields spanning the entire period of the observations. It therefore becomes possible to solve larger inverse problems with more observations and for fluxes discretized at finer spatial scales. We also discuss the differences between running the inversion simultaneously with the 20 transport model and running it entirely off-line with pre-calculated transport fields. We find that the latter can be done with minimal error if time series of transport fields of adequate length are pre-calculated.

  18. MOTIVATION

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Introduction What is the difference between instrumental and integrative motivation? What kind of motivations do students have? How can our knowledge of motivation help the language learning process? Motivation can be very important in language teaching. Students can do very well when they are motivated. Teachers, with their knowledge of motivation, can make their classes more efficient and successful. Middle school teachers, in addition to learning about the English language itself, and about teaching methods, should also learn more about motivation and how this affects our students. "When we consider language teaching, motivation can be classified as either integrative or instrumental motivation" (Luxon)

  19. Gender and Facebook motives as predictors of specific types of Facebook use: A latent growth curve analysis in adolescence.

    Science.gov (United States)

    Frison, Eline; Eggermont, Steven

    2016-10-01

    Despite increasing evidence that specific types of Facebook use (i.e., active private, active public, and passive Facebook use) are differently related to adolescents' well-being, little is known how these types function over the course of adolescence and whether gender and Facebook motives may predict the initial level and changes in these types over time. To address these gaps, Flemish adolescents (ages 12-19) were questioned at three different time points, with six months in between (NTime1 = 1866). Latent growth curve models revealed that active private Facebook use increased over the course of adolescence, whereas public Facebook use decreased. Passive Facebook use, however, remained stable. In addition, gender and Facebook motives were related to initial levels of specific types of Facebook use, and predictive of dynamic change in specific types of Facebook use over time. The discussion focuses on the understanding and implications of these findings.

  20. Aggressive, accelerated subdomain smoothers for Stokes flow with highly heterogeneous viscosity structure

    Science.gov (United States)

    Sanan, Patrick; May, Dave; Schenk, Olaf; Rupp, Karl

    2016-04-01

    Scalable solvers for mantle convection and lithospheric dynamics with highly heterogeneous viscosity structure typically require the use of a multigrid method. To leverage new hybrid CPU-accelerator architectures on leadership compute clusters, multigrid hierarchies which can reduce communication and use high available arithmetic intensity are at a premium, motivating more aggressive coarsening schemes and smoothers. We present results of a comparative study of two competitive GPU-enabled subdomain smoothers within an additive Schwarz method. Chebyshev-Jacobi smoothing has been shown to be an effective smoother, and its nature as a low-communication method built from basic linear algebra routines allows its use on a wide range of devices with current libraries. ILU smoothing is also of interest and is known to provide robust smoothing in some cases, but has traditionally been difficult to use in a fine-grained parallel environment. However, a recently-introduced variant by Chow and Patel allows for incomplete factorizations to be computed and applied in these environments, hence allowing us to study them as well. We use and extend the pTatin3D, PETSc, and ViennaCL libraries to integrate promising methods into a realistic application framework.

  1. Motivation.

    Science.gov (United States)

    Chambers, David W

    2007-01-01

    Motivation is short-term focused energy. The oldest theories of motivation explain motivated activity as effort to overcome primary deficiencies, such as hunger or boredom. Such theories are difficult to apply because individuals learn idiosyncratic secondary motives as alternative ways of responding to these needs. Three prominent needs theories are discussed: Herzberg's theory of hygiene and motivational factors; McClelland's needs for achievement, power, and affiliation; and Maslow's hierarchy and theory of self-actualization. A second approach to motivation holds that individuals may be thought of as engaging in rational processes to maximize their self-interests. The presented examples of this approach include Vroom's expectancy theory, Adam's theory of inequality, and the Porter-Lawler model that addresses the question of whether satisfaction leads to high performance or vice versa. Finally, several theories of motivation as life orientation are developed.

  2. Finite volume adaptive solutions using SIMPLE as smoother

    CERN Document Server

    Syrakos, Alexandros

    2015-01-01

    This paper describes a new multilevel procedure that can solve the discrete Navier-Stokes system arising from finite volume discretizations on composite grids, which may consist of more than one level. SIMPLE is used and tested as the smoother, but the multilevel procedure is such that it does not exclude the use of other smoothers. Local refinement is guided by a criterion based on an estimate of the truncation error. The numerical experiments presented test not only the behaviour of the multilevel algebraic solver, but also the efficiency of local refinement based on this particular criterion.

  3. On the robustness of ILU smoothers on triangular grids

    NARCIS (Netherlands)

    Pinto, M.A.V.; Rodrigo, C.; Gaspar Lorenz, F.J.; Oosterlee, C.W.

    2016-01-01

    In this work, incomplete factorization techniques are used as smoothers within a geometric multigrid algorithm on triangular grids. A local Fourier analysis is proposed to study the smoothing properties of these methods, as well as the asymptotic convergence of the whole multigrid procedure. With th

  4. Recursive bias estimation for high dimensional regression smoothers

    Energy Technology Data Exchange (ETDEWEB)

    Hengartner, Nicolas W [Los Alamos National Laboratory; Cornillon, Pierre - Andre [AGROSUP, FRANCE; Matzner - Lober, Eric [UNIV OF RENNES, FRANCE

    2009-01-01

    In multivariate nonparametric analysis, sparseness of the covariates also called curse of dimensionality, forces one to use large smoothing parameters. This leads to biased smoother. Instead of focusing on optimally selecting the smoothing parameter, we fix it to some reasonably large value to ensure an over-smoothing of the data. The resulting smoother has a small variance but a substantial bias. In this paper, we propose to iteratively correct of the bias initial estimator by an estimate of the latter obtained by smoothing the residuals. We examine in details the convergence of the iterated procedure for classical smoothers and relate our procedure to L{sub 2}-Boosting, For multivariate thin plate spline smoother, we proved that our procedure adapts to the correct and unknown order of smoothness for estimating an unknown function m belonging to H({nu}) (Sobolev space where m should be bigger than d/2). We apply our method to simulated and real data and show that our method compares favorably with existing procedures.

  5. A new class of nonlinear Rauch-Tung-Striebel cubature Kalman smoothers.

    Science.gov (United States)

    Jia, Bin; Xin, Ming

    2015-03-01

    In this paper, a new Rauch-Tung-Striebel type of nonlinear smoothing method is proposed based on a class of high-degree cubature integration rules. This new class of cubature Kalman smoothers generalizes the conventional third-degree cubature Kalman smoother using the combination of Genz׳s or Mysovskikh׳s high-degree spherical rule with the moment matching based arbitrary-degree radial rule, which considerably improves the estimation accuracy. A target tracking problem is utilized to demonstrate the performance of this new smoother and to compare it with other Gaussian approximation smoothers. It will be shown that this new cubature Kalman smoother enhances the filtering accuracy and outperforms the extended Kalman smoother, the unscented Kalman smoother, and the conventional third-degree cubature Kalman smoother. It also maintains close performance to the Gauss-Hermite quadrature smoother with much less computational cost.

  6. Changes in teachers' involvement versus rejection and links with academic motivation during the first year of secondary education: a multilevel growth curve analysis.

    Science.gov (United States)

    Maulana, Ridwan; Opdenakker, Marie-Christine; Stroet, Kim; Bosker, Roel

    2013-09-01

    Research consistently shows that the learning environment plays an important role for early adolescents' learning and outcomes and suggests that good teacher-student relationships can serve as a protective factor for maintaining young adolescents' interest and active engagement in learning. However, less is known about the dynamic nature of teacher-student relationships and how they link with academic motivation development. Furthermore, little is known about the nature and the effects of teacher-student relationships in a cross-national context. The present study investigated changes in two components of teacher-student relationships (teachers' involvement vs. rejection) and examined links with students' academic motivation during the first grade of secondary school. Ten Dutch and ten Indonesian teachers (65 % female) from 24 classes were videoed 12 times across the school year, and four videos for each class were selected randomly and coded on teachers' involvement versus rejection. A total of 713 students (52 % girls) completed four-wave measures of their academic motivation after each video observation. Multilevel growth curve modeling revealed that the teacher's involvement changed in a curvilinear way and decreased across the first year of secondary education, while changes in the teacher's rejection did not follow a linear time function. Academic motivation changed in an undesirable way: controlled motivation increased, while autonomous motivation decreased over time. Teachers' involvement had a unique contribution in preventing high levels of controlled motivation in both countries. Findings suggest that teacher-student relationships (teachers' involvement) play an essential role in early adolescents' motivation regardless of the nations and should be a priority for schools.

  7. Tweed Relaxation: a new multigrid smoother for stretched structured grids

    Science.gov (United States)

    Bewley, Thomas; Mashayekhi, Alireza

    2012-11-01

    In DNS/LES of the NSE using a fractional step method, one must accurately solve a Poisson equation for the pressure update at each timestep. This step often represents a significant fraction of the overall computational burden and, when Fourier methods are unavailable, geometric multigrid methods are a preferred choice. When working on an unstretched Cartesian grid, the red-black Gauss-Seidel method is the most efficient multigrid smoother available. When working on a Cartesian grid that is stretched in 1 coordinate direction to provide grid clustering near a wall, zebra relaxation, on sets of lines perpendicular to the wall, is most efficient. When working on a structured grid that is stretched in 2 or 3 coordinate directions, however, one is forced to alternate the directions that the zebra relaxation is applied in order to pass information quickly across all regions of grid clustering. A new relaxation method is introduced which is shown to significantly outperform such alternating direction line smoothers. This new method is implicit along sets of lines that branch and form 90° corners, like the stripes at the shoulder of a tweed shirt, to stay everywhere perpendicular to the nearest wall, thus passing information quickly across all regions of grid clustering.

  8. Four-dimensional Localization and the Iterative Ensemble Kalman Smoother

    Science.gov (United States)

    Bocquet, M.

    2015-12-01

    The iterative ensemble Kalman smoother (IEnKS) is a data assimilation method meant for efficiently tracking the state ofnonlinear geophysical models. It combines an ensemble of model states to estimate the errors similarly to the ensemblesquare root Kalman filter, with a 4D-variational analysis performed within the ensemble space. As such it belongs tothe class of ensemble variational methods. Recently introduced 4DEnVar or the 4D-LETKF can be seen as particular casesof the scheme. The IEnKS was shown to outperform 4D-Var, the ensemble Kalman filter (EnKF) and smoother, with low-ordermodels in all investigated dynamical regimes. Like any ensemble method, it could require the use of localization of theanalysis when the state space dimension is high. However, localization for the IEnKS is not as straightforward as forthe EnKF. Indeed, localization needs to be defined across time, and it needs to be as much as possible consistent withthe dynamical flow within the data assimilation variational window. We show that a Liouville equation governs the timeevolution of the localization operator, which is linked to the evolution of the error correlations. It is argued thatits time integration strongly depends on the forecast dynamics. Using either covariance localization or domainlocalization, we propose and test several localization strategies meant to address the issue: (i) a constant and uniformlocalization, (ii) the propagation through the window of a restricted set of dominant modes of the error covariancematrix, (iii) the approximate propagation of the localization operator using model covariant local domains. Theseschemes are illustrated on the one-dimensional Lorenz 40-variable model.

  9. The Behavior of Filters and Smoothers for Strongly Nonlinear Dynamics

    Science.gov (United States)

    Zhu, Yanqiu; Cohn, Stephen E.; Todling, Ricardo

    1999-01-01

    The Kalman filter is the optimal filter in the presence of known Gaussian error statistics and linear dynamics. Filter extension to nonlinear dynamics is non trivial in the sense of appropriately representing high order moments of the statistics. Monte Carlo, ensemble-based, methods have been advocated as the methodology for representing high order moments without any questionable closure assumptions (e.g., Miller 1994). Investigation along these lines has been conducted for highly idealized dynamics such as the strongly nonlinear Lorenz (1963) model as well as more realistic models of the oceans (Evensen and van Leeuwen 1996) and atmosphere (Houtekamer and Mitchell 1998). A few relevant issues in this context are related to the necessary number of ensemble members to properly represent the error statistics and, the necessary modifications in the usual filter equations to allow for correct update of the ensemble members (Burgers 1998). The ensemble technique has also been applied to the problem of smoothing for which similar questions apply. Ensemble smoother examples, however, seem to quite puzzling in that results of state estimate are worse than for their filter analogue (Evensen 1997). In this study, we use concepts in probability theory to revisit the ensemble methodology for filtering and smoothing in data assimilation. We use Lorenz (1963) model to test and compare the behavior of a variety implementations of ensemble filters. We also implement ensemble smoothers that are able to perform better than their filter counterparts. A discussion of feasibility of these techniques to large data assimilation problems will be given at the time of the conference.

  10. Automated smoother for the numerical decoupling of dynamics models

    Directory of Open Access Journals (Sweden)

    Santos Helena

    2007-08-01

    Full Text Available Abstract Background Structure identification of dynamic models for complex biological systems is the cornerstone of their reverse engineering. Biochemical Systems Theory (BST offers a particularly convenient solution because its parameters are kinetic-order coefficients which directly identify the topology of the underlying network of processes. We have previously proposed a numerical decoupling procedure that allows the identification of multivariate dynamic models of complex biological processes. While described here within the context of BST, this procedure has a general applicability to signal extraction. Our original implementation relied on artificial neural networks (ANN, which caused slight, undesirable bias during the smoothing of the time courses. As an alternative, we propose here an adaptation of the Whittaker's smoother and demonstrate its role within a robust, fully automated structure identification procedure. Results In this report we propose a robust, fully automated solution for signal extraction from time series, which is the prerequisite for the efficient reverse engineering of biological systems models. The Whittaker's smoother is reformulated within the context of information theory and extended by the development of adaptive signal segmentation to account for heterogeneous noise structures. The resulting procedure can be used on arbitrary time series with a nonstationary noise process; it is illustrated here with metabolic profiles obtained from in-vivo NMR experiments. The smoothed solution that is free of parametric bias permits differentiation, which is crucial for the numerical decoupling of systems of differential equations. Conclusion The method is applicable in signal extraction from time series with nonstationary noise structure and can be applied in the numerical decoupling of system of differential equations into algebraic equations, and thus constitutes a rather general tool for the reverse engineering of

  11. Design of RLS Wiener Fixed-Lag Smoother in Linear Discrete-Time Stochastic Systems

    OpenAIRE

    2015-01-01

    This paper newly presents the recursive least-squares (RLS) fixed-lag smoother using the covariance information and then the RLS Wiener fixed-lag smoother in linear discrete-time wide-sense stationary stochastic systems. Here, the additional disturbance in the measurement of the signal is white noise. The signal is uncorrelated with observed noise. It is assumed that the signal process is fitted to the autoregressive (AR) model of order NN. For this AR model of order NN, in the proposed fixed...

  12. Study of the Effectiveness of Different Kalman Filtering Methods and Smoothers in Object Tracking Based on Simulation Tests

    Directory of Open Access Journals (Sweden)

    Malinowski Marcin

    2015-02-01

    Full Text Available In navigation practice, there are various navigational architecture and integration strategies of measuring instruments that affect the choice of the Kalman filtering algorithm. The analysis of different methods of Kalman filtration and associated smoothers applied in object tracing was made on the grounds of simulation tests of algorithms designed and presented in this paper. EKF (Extended Kalman Filter filter based on approximation with (jacobians partial derivations and derivative-free filters like UKF (Unscented Kalman Filter and CDKF (Central Difference Kalman Filter were implemented in comparison. For each method of filtration, appropriate smoothers EKS (Extended Kalman Smoother, UKS (Unscented Kalman Smoother and CDKS (Central Difference Kalman Smoother were presented as well. Algorithms performance is discussed on the theoretical base and simulation results of two cases are presented.

  13. Comparison of Kalman filter and optimal smoother estimates of spacecraft attitude

    Science.gov (United States)

    Sedlak, J.

    1994-01-01

    Given a valid system model and adequate observability, a Kalman filter will converge toward the true system state with error statistics given by the estimated error covariance matrix. The errors generally do not continue to decrease. Rather, a balance is reached between the gain of information from new measurements and the loss of information during propagation. The errors can be further reduced, however, by a second pass through the data with an optimal smoother. This algorithm obtains the optimally weighted average of forward and backward propagating Kalman filters. It roughly halves the error covariance by including future as well as past measurements in each estimate. This paper investigates whether such benefits actually accrue in the application of an optimal smoother to spacecraft attitude determination. Tests are performed both with actual spacecraft data from the Extreme Ultraviolet Explorer (EUVE) and with simulated data for which the true state vector and noise statistics are exactly known.

  14. Smoother and Bayesian filter based semi-codeless tracking of dual-frequency GPS signals

    Institute of Scientific and Technical Information of China (English)

    LIAO Bingyu; YUAN Hong; LIN Baojun

    2006-01-01

    To precisely determine the integrated orbit of the Chinese manned spacecraft mission,a smoother and Bayesian filter based technique for optimum semi-codeless tracking of the P(Y) code on dual-frequency GPS signals has been advanced. This signal processing technique has been proven effective and robust for affording access to dual-frequency GPS signals. This paper introduces the signal dynamics and measurement models, describes the W·D bit estimation method, and corrects the mistakes of direct estimation of W bit in current semi-codeless tracking. Median filter is chosen as a smoother to find the best measurements at the current time among the history and current information. The Bayesian filter is used to track the L2 P(Y) code phase and L2 carrier phase recursively.

  15. Semicoarsening and Implicit Smoothers for the Simulation of a Flat Plate at Yaw

    Science.gov (United States)

    2001-05-01

    Semicoarsening and Implicit Smoothers for the Simulation of a Flat Plate at Yaw Ruben S. Montero and Ignacio M. Llorente Universidad Complutense , Madrid...yDepartamento de Arquitectura de Computadores y Automatica, Universidad Complutense , 28040 Madrid, Spain zDepartamento de Arquitectura de Computadores...y Automatica, Universidad Complutense , 28040 Madrid, Spain xICASE, Mail Stop 132C, NASA Langley Research Center, Hampton, VA 23681-2199 1

  16. Hybrid Levenberg-Marquardt and weak-constraint ensemble Kalman smoother method

    Science.gov (United States)

    Mandel, J.; Bergou, E.; Gürol, S.; Gratton, S.; Kasanický, I.

    2016-03-01

    The ensemble Kalman smoother (EnKS) is used as a linear least-squares solver in the Gauss-Newton method for the large nonlinear least-squares system in incremental 4DVAR. The ensemble approach is naturally parallel over the ensemble members and no tangent or adjoint operators are needed. Furthermore, adding a regularization term results in replacing the Gauss-Newton method, which may diverge, by the Levenberg-Marquardt method, which is known to be convergent. The regularization is implemented efficiently as an additional observation in the EnKS. The method is illustrated on the Lorenz 63 model and a two-level quasi-geostrophic model.

  17. An Ensemble-Based Smoother with Retrospectively Updated Weights for Highly Nonlinear Systems

    Science.gov (United States)

    Chin, T. M.; Turmon, M. J.; Jewell, J. B.; Ghil, M.

    2006-01-01

    Monte Carlo computational methods have been introduced into data assimilation for nonlinear systems in order to alleviate the computational burden of updating and propagating the full probability distribution. By propagating an ensemble of representative states, algorithms like the ensemble Kalman filter (EnKF) and the resampled particle filter (RPF) rely on the existing modeling infrastructure to approximate the distribution based on the evolution of this ensemble. This work presents an ensemble-based smoother that is applicable to the Monte Carlo filtering schemes like EnKF and RPF. At the minor cost of retrospectively updating a set of weights for ensemble members, this smoother has demonstrated superior capabilities in state tracking for two highly nonlinear problems: the double-well potential and trivariate Lorenz systems. The algorithm does not require retrospective adaptation of the ensemble members themselves, and it is thus suited to a streaming operational mode. The accuracy of the proposed backward-update scheme in estimating non-Gaussian distributions is evaluated by comparison to the more accurate estimates provided by a Markov chain Monte Carlo algorithm.

  18. Joint state and parameter estimation of the hemodynamic model by particle smoother expectation maximization method

    Science.gov (United States)

    Aslan, Serdar; Taylan Cemgil, Ali; Akın, Ata

    2016-08-01

    Objective. In this paper, we aimed for the robust estimation of the parameters and states of the hemodynamic model by using blood oxygen level dependent signal. Approach. In the fMRI literature, there are only a few successful methods that are able to make a joint estimation of the states and parameters of the hemodynamic model. In this paper, we implemented a maximum likelihood based method called the particle smoother expectation maximization (PSEM) algorithm for the joint state and parameter estimation. Main results. Former sequential Monte Carlo methods were only reliable in the hemodynamic state estimates. They were claimed to outperform the local linearization (LL) filter and the extended Kalman filter (EKF). The PSEM algorithm is compared with the most successful method called square-root cubature Kalman smoother (SCKS) for both state and parameter estimation. SCKS was found to be better than the dynamic expectation maximization (DEM) algorithm, which was shown to be a better estimator than EKF, LL and particle filters. Significance. PSEM was more accurate than SCKS for both the state and the parameter estimation. Hence, PSEM seems to be the most accurate method for the system identification and state estimation for the hemodynamic model inversion literature. This paper do not compare its results with Tikhonov-regularized Newton—CKF (TNF-CKF), a recent robust method which works in filtering sense.

  19. Achieving comparable uncertainty estimates with Kalman filters or linear smoothers for bathymetry data

    Science.gov (United States)

    Bourgeois, Brian S.; Elmore, Paul A.; Avera, William E.; Zambo, Samantha J.

    2016-07-01

    This paper examines and contrasts two estimation methods, Kalman filtering and linear smoothing, for creating interpolated data products from bathymetry measurements. Using targeted examples, we demonstrate previously obscured behavior showing the dependence of linear smoothers on the spatial arrangement of the measurements, yielding markedly different estimation results than the Kalman filter. For bathymetry data, we have modified the variance estimates from both the Kalman filter and linear smoothers to obtain comparable estimators for dense data. These comparable estimators produce uncertainty estimates that have statistically insignificant differences via hypothesis testing. Achieving comparable estimation is accomplished by applying the "propagated uncertainty" concept and a numerical realization of Tobler's principle to the measurement data prior to the computation of the estimate. We show new mathematical derivations for these modifications. In addition, we show test results with (a) synthetic data and (b) gridded bathymetry in the area of the Scripps and La Jolla Canyons. Our tenfold cross-validation for case (b) shows that the modified equations create comparable uncertainty for both gridding algorithms with null hypothesis acceptance rates of greater than 99.95% of the data points. In contrast, bilinear interpolation has 10 times the amount of rejection. We then discuss how the uncertainty estimators are, in principle, applicable to interpolate geophysical data other than bathymetry.

  20. Hybrid Levenberg–Marquardt and weak constraint ensemble Kalman smoother method

    Directory of Open Access Journals (Sweden)

    J. Mandel

    2015-05-01

    Full Text Available We propose to use the ensemble Kalman smoother (EnKS as the linear least squares solver in the Gauss–Newton method for the large nonlinear least squares in incremental 4DVAR. The ensemble approach is naturally parallel over the ensemble members and no tangent or adjoint operators are needed. Further, adding a regularization term results in replacing the Gauss–Newton method, which may diverge, by the Levenberg–Marquardt method, which is known to be convergent. The regularization is implemented efficiently as an additional observation in the EnKS. The method is illustrated on the Lorenz 63 and the two-level quasi-geostrophic model problems.

  1. Using an ensemble smoother to evaluate parameter uncertainty of an integrated hydrological model of Yanqi basin

    Science.gov (United States)

    Li, Ning; McLaughlin, Dennis; Kinzelbach, Wolfgang; Li, WenPeng; Dong, XinGuang

    2015-10-01

    Model uncertainty needs to be quantified to provide objective assessments of the reliability of model predictions and of the risk associated with management decisions that rely on these predictions. This is particularly true in water resource studies that depend on model-based assessments of alternative management strategies. In recent decades, Bayesian data assimilation methods have been widely used in hydrology to assess uncertain model parameters and predictions. In this case study, a particular data assimilation algorithm, the Ensemble Smoother with Multiple Data Assimilation (ESMDA) (Emerick and Reynolds, 2012), is used to derive posterior samples of uncertain model parameters and forecasts for a distributed hydrological model of Yanqi basin, China. This model is constructed using MIKESHE/MIKE11software, which provides for coupling between surface and subsurface processes (DHI, 2011a-d). The random samples in the posterior parameter ensemble are obtained by using measurements to update 50 prior parameter samples generated with a Latin Hypercube Sampling (LHS) procedure. The posterior forecast samples are obtained from model runs that use the corresponding posterior parameter samples. Two iterative sample update methods are considered: one based on an a perturbed observation Kalman filter update and one based on a square root Kalman filter update. These alternatives give nearly the same results and converge in only two iterations. The uncertain parameters considered include hydraulic conductivities, drainage and river leakage factors, van Genuchten soil property parameters, and dispersion coefficients. The results show that the uncertainty in many of the parameters is reduced during the smoother updating process, reflecting information obtained from the observations. Some of the parameters are insensitive and do not benefit from measurement information. The correlation coefficients among certain parameters increase in each iteration, although they generally

  2. Estimation of Launch and Impact Points of a Flight Trajectory using U-D Kalman Filter/Smoother

    Directory of Open Access Journals (Sweden)

    V.P.S. Naidu

    2006-10-01

    Full Text Available The launch and impact points of a flight trajectory are estimated using U-D Kalman filterand Rauch-Tung-Striebel (R-T-S smoother. Algorithms are implemented in PC MATLAB andvalidated using simulated data. The filter performance is evaluated in terms of state error,innovation sequence, and autocorrelation of residuals along with their theoretical bounds. TheR-T-S smoother was found to generate accurate state estimates, which led to better launch pointestimation. Launch and impact point prediction from real data of a guided target in ballistic modeis also evaluated.

  3. State-Space Modeling of Dynamic Psychological Processes via the Kalman Smoother Algorithm: Rationale, Finite Sample Properties, and Applications

    Science.gov (United States)

    Song, Hairong; Ferrer, Emilio

    2009-01-01

    This article presents a state-space modeling (SSM) technique for fitting process factor analysis models directly to raw data. The Kalman smoother via the expectation-maximization algorithm to obtain maximum likelihood parameter estimates is used. To examine the finite sample properties of the estimates in SSM when common factors are involved, a…

  4. A simple smoother based on continuous wavelet transform: Comparative evaluation based on the fidelity, smoothness and efficiency in phenological estimation

    Science.gov (United States)

    Qiu, Bingwen; Feng, Min; Tang, Zhenghong

    2016-05-01

    This study proposed a simple Smoother without any local adjustments based on Continuous Wavelet Transform (SCWT). And then it evaluated its performance together with other commonly applied techniques in phenological estimation. These noise reduction methods included Savitzky-Golay filter (SG), Double Logistic function (DL), Asymmetric Gaussian function (AG), Whittaker Smoother (WS) and Harmonic Analysis of Time-Series (HANTS). They were evaluated based on fidelity and smoothness, and their efficiencies in deriving phenological parameters through the inflexion point-based method with the 8-day composite Moderate Resolution Imaging Spectroradiometer (MODIS) 2-band Enhanced Vegetation Index (EVI2) in 2013 in China. The following conclusions were drawn: (1) The SG method exhibited strong fidelity, but weak smoothness and spatial continuity. (2) The HANTS method had very robust smoothness but weak fidelity. (3) The AG and DL methods performed weakly for vegetation with more than one growth cycle (i.e., multiple crops). (4) The WS and SCWT smoothers outperformed others with combined considerations of fidelity and smoothness, and consistent phenological patterns (correlation coefficients greater than 0.8 except evergreen broadleaf forests (0.68)). (5) Compared with WS methods, the SCWT smoother was capable in preservation of real local minima and maxima with fewer inflexions. (6) Large discrepancy was examined from the estimated phenological dates with SG and HANTS methods, particularly in evergreen forests and multiple cropping regions (the absolute mean deviation rates were 6.2-17.5 days and correlation coefficients less than 0.34 for estimated start dates).

  5. A Fusion Approach of RSSI and LQI for Indoor Localization System Using Adaptive Smoothers

    Directory of Open Access Journals (Sweden)

    Sharly Joana Halder

    2012-01-01

    Full Text Available Due to the ease of development and inexpensiveness, indoor localization systems are getting a significant attention but, with recent advancement in context and location aware technologies, the solutions for indoor tracking and localization had become more critical. Ranging methods play a basic role in the localization system, in which received signal strength indicator- (RSSI- based ranging technique gets the most attraction. To predict the position of an unknown node, RSSI measurement is an easy and reliable method for distance estimation. In indoor environments, the accuracy of the RSSI-based localization method is affected by strong variation, specially often containing substantial amounts of metal and other such reflective materials that affect the propagation of radio-frequency signals in nontrivial ways, causing multipath effects, dead spots, noise, and interference. This paper proposes an adaptive smoother based location and tracking algorithm for indoor positioning by making fusion of RSSI and link quality indicator (LQI, which is particularly well suited to support context aware computing. The experimental results showed that the proposed mathematical method can reduce the average error around 25%, and it is always better than the other existing interference avoidance algorithms.

  6. Ensemble Kalman filter versus ensemble smoother for assessing hydraulic conductivity via tracer test data assimilation

    Directory of Open Access Journals (Sweden)

    E. Crestani

    2013-04-01

    Full Text Available Estimating the spatial variability of hydraulic conductivity K in natural aquifers is important for predicting the transport of dissolved compounds. Especially in the nonreactive case, the plume evolution is mainly controlled by the heterogeneity of K. At the local scale, the spatial distribution of K can be inferred by combining the Lagrangian formulation of the transport with a Kalman-filter-based technique and assimilating a sequence of time-lapse concentration C measurements, which, for example, can be evaluated on site through the application of a geophysical method. The objective of this work is to compare the ensemble Kalman filter (EnKF and the ensemble smoother (ES capabilities to retrieve the hydraulic conductivity spatial distribution in a groundwater flow and transport modeling framework. The application refers to a two-dimensional synthetic aquifer in which a tracer test is simulated. Moreover, since Kalman-filter-based methods are optimal only if each of the involved variables fit to a Gaussian probability density function (pdf and since this condition may not be met by some of the flow and transport state variables, issues related to the non-Gaussianity of the variables are analyzed and different transformation of the pdfs are considered in order to evaluate their influence on the performance of the methods. The results show that the EnKF reproduces with good accuracy the hydraulic conductivity field, outperforming the ES regardless of the pdf of the concentrations.

  7. Surrogate model based iterative ensemble smoother for subsurface flow data assimilation

    Science.gov (United States)

    Chang, Haibin; Liao, Qinzhuo; Zhang, Dongxiao

    2017-02-01

    Subsurface geological formation properties often involve some degree of uncertainty. Thus, for most conditions, uncertainty quantification and data assimilation are necessary for predicting subsurface flow. The surrogate model based method is one common type of uncertainty quantification method, in which a surrogate model is constructed for approximating the relationship between model output and model input. Based on the prediction ability, the constructed surrogate model can be utilized for performing data assimilation. In this work, we develop an algorithm for implementing an iterative ensemble smoother (ES) using the surrogate model. We first derive an iterative ES scheme using a regular routine. In order to utilize surrogate models, we then borrow the idea of Chen and Oliver (2013) to modify the Hessian, and further develop an independent parameter based iterative ES formula. Finally, we establish the algorithm for the implementation of iterative ES using surrogate models. Two surrogate models, the PCE surrogate and the interpolation surrogate, are introduced for illustration. The performances of the proposed algorithm are tested by synthetic cases. The results show that satisfactory data assimilation results can be obtained by using surrogate models that have sufficient accuracy.

  8. Agglomeration multigrid methods with implicit Runge-Kutta smoothers applied to aerodynamic simulations on unstructured grids

    Science.gov (United States)

    Langer, Stefan

    2014-11-01

    For unstructured finite volume methods an agglomeration multigrid with an implicit multistage Runge-Kutta method as a smoother is developed for solving the compressible Reynolds averaged Navier-Stokes (RANS) equations. The implicit Runge-Kutta method is interpreted as a preconditioned explicit Runge-Kutta method. The construction of the preconditioner is based on an approximate derivative. The linear systems are solved approximately with a symmetric Gauss-Seidel method. To significantly improve this solution method grid anisotropy is treated within the Gauss-Seidel iteration in such a way that the strong couplings in the linear system are resolved by tridiagonal systems constructed along these directions of strong coupling. The agglomeration strategy is adapted to this procedure by taking into account exactly these anisotropies in such a way that a directional coarsening is applied along these directions of strong coupling. Turbulence effects are included by a Spalart-Allmaras model, and the additional transport-type equation is approximately solved in a loosely coupled manner with the same method. For two-dimensional and three-dimensional numerical examples and a variety of differently generated meshes we show the wide range of applicability of the solution method. Finally, we exploit the GMRES method to determine approximate spectral information of the linearized RANS equations. This approximate spectral information is used to discuss and compare characteristics of multistage Runge-Kutta methods.

  9. Extended Kalman smoother with differential evolution technique for denoising of ECG signal.

    Science.gov (United States)

    Panigrahy, D; Sahu, P K

    2016-09-01

    Electrocardiogram (ECG) signal gives a lot of information on the physiology of heart. In reality, noise from various sources interfere with the ECG signal. To get the correct information on physiology of the heart, noise cancellation of the ECG signal is required. In this paper, the effectiveness of extended Kalman smoother (EKS) with the differential evolution (DE) technique for noise cancellation of the ECG signal is investigated. DE is used as an automatic parameter selection method for the selection of ten optimized components of the ECG signal, and those are used to create the ECG signal according to the real ECG signal. These parameters are used by the EKS for the development of the state equation and also for initialization of the parameters of EKS. EKS framework is used for denoising the ECG signal from the single channel. The effectiveness of proposed noise cancellation technique has been evaluated by adding white, colored Gaussian noise and real muscle artifact noise at different SNR to some visually clean ECG signals from the MIT-BIH arrhythmia database. The proposed noise cancellation technique of ECG signal shows better signal to noise ratio (SNR) improvement, lesser mean square error (MSE) and percent of distortion (PRD) compared to other well-known methods.

  10. Obstacles and benefits of the implementation of a reduced-rank smoother with a high resolution model of the tropical Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    N. Freychet

    2012-09-01

    Full Text Available Most of oceanographic operational centers use three-dimensional data assimilation schemes to produce reanalyses. We investigate here the benefits of a smoother, i.e. a four-dimensional formulation of statistical assimilation. A square-root sequential smoother is implemented with a tropical Atlantic Ocean circulation model. A simple twin experiment is performed to investigate its benefits, compared to its corresponding filter. Despite model's non-linearities and the various approximations used for its implementation, the smoother leads to a better estimation of the ocean state, both on statistical (i.e. mean error level and dynamical points of view, as expected from linear theory. Smoothed states are more in phase with the dynamics of the reference state, an aspect that is nicely illustrated with the chaotic dynamics of the North Brazil Current rings. We also show that the smoother efficiency is strongly related to the filter configuration. One of the main obstacles to implement the smoother is then to accurately estimate the error covariances of the filter. Considering this, benefits of the smoother are also investigated with a configuration close to situations that can be managed by operational center systems, where covariances matrices are fixed (optimal interpolation. We define here a simplified smoother scheme, called half-fixed basis smoother, that could be implemented with current reanalysis schemes. Its main assumption is to neglect the propagation of the error covariances matrix, what leads to strongly reduce the cost of assimilation. Results illustrate the ability of this smoother to provide a solution more consistent with the dynamics, compared to the filter. The smoother is also able to produce analyses independently of the observation frequency, so the smoothed solution appears more continuous in time, especially in case of a low frenquency observation network.

  11. Ensemble Kalman filter versus ensemble smoother for assessing hydraulic conductivity via tracer test data assimilation

    Directory of Open Access Journals (Sweden)

    E. Crestani

    2012-11-01

    Full Text Available The significance of estimating the spatial variability of the hydraulic conductivity K in natural aquifers is relevant to the possibility of defining the space and time evolution of a non-reactive plume, since the transport of a solute is mainly controlled by the heterogeneity of K. At the local scale, the spatial distribution of K can be inferred by combining the Lagrangian formulation of the transport with a Kalman filter-based technique and assimilating a sequence of time-lapse concentration C measurements, which, for example, can be evaluated on-site through the application of a geophysical method. The objective of this work is to compare the ensemble Kalman filter (EnKF and the ensemble smoother (ES capabilities to retrieve the hydraulic conductivity spatial distribution in a groundwater flow and transport modeling framework. The application refers to a two-dimensional synthetic aquifer in which a tracer test is simulated. Moreover, since Kalman filter-based methods are optimal only if each of the involved variables fit to a Gaussian probability density function (pdf and since this condition may not be met by some of the flow and transport state variables, issues related to the non-Gaussianity of the variables are analyzed and different transformation of the pdfs are considered in order to evaluate their influence on the performance of the methods. The results show that the EnKF reproduces with good accuracy the hydraulic conductivity field, outperforming the ES regardless of the pdf of the concentrations.

  12. A Parameter Estimation Scheme for Multiscale Kalman Smoother (MKS) Algorithm Used in Precipitation Data Fusion

    Science.gov (United States)

    Wang, Shugong; Liang, Xu

    2013-01-01

    A new approach is presented in this paper to effectively obtain parameter estimations for the Multiscale Kalman Smoother (MKS) algorithm. This new approach has demonstrated promising potentials in deriving better data products based on data of different spatial scales and precisions. Our new approach employs a multi-objective (MO) parameter estimation scheme (called MO scheme hereafter), rather than using the conventional maximum likelihood scheme (called ML scheme) to estimate the MKS parameters. Unlike the ML scheme, the MO scheme is not simply built on strict statistical assumptions related to prediction errors and observation errors, rather, it directly associates the fused data of multiple scales with multiple objective functions in searching best parameter estimations for MKS through optimization. In the MO scheme, objective functions are defined to facilitate consistency among the fused data at multiscales and the input data at their original scales in terms of spatial patterns and magnitudes. The new approach is evaluated through a Monte Carlo experiment and a series of comparison analyses using synthetic precipitation data. Our results show that the MKS fused precipitation performs better using the MO scheme than that using the ML scheme. Particularly, improvements are significant compared to that using the ML scheme for the fused precipitation associated with fine spatial resolutions. This is mainly due to having more criteria and constraints involved in the MO scheme than those included in the ML scheme. The weakness of the original ML scheme that blindly puts more weights onto the data associated with finer resolutions is overcome in our new approach.

  13. Aircraft flight data processing and parameter identification with iterative extended Kalman filter/smoother and two-step estimator

    Science.gov (United States)

    Yu, Qiuli

    2001-12-01

    Aircraft flight test data are processed by optimal estimation programs to estimate the aircraft state trajectory (3 DOF) and to identify the unknown parameters, including constant biases and scale factor of the measurement instrumentation system. The methods applied in processing aircraft flight test data are the iterative extended Kalman filter/smoother and fixed-point smoother (IEKFSFPS) method and the two-step estimator (TSE) method. The models of an aircraft flight dynamic system and measurement instrumentation system are established. The principles of IEKFSFPS and TSE methods are derived and summarized, and their algorithms are programmed with MATLAB codes. Several numerical experiments of flight data processing and parameter identification are carried out by using IEKFSFPS and TSE algorithm programs. Comparison and discussion of the simulation results with the two methods are made. The TSE+IEKFSFPS combination method is presented and proven to be effective and practical. Figures and tables of the results are presented.

  14. Twisted Vector Bundles on Pointed Nodal Curves

    Indian Academy of Sciences (India)

    Ivan Kausz

    2005-05-01

    Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich’s and Vistoli’s twisted bundles and Gieseker vector bundles.

  15. Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    Fei-Bin Hsiao

    2011-03-01

    Full Text Available This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV. The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA and angle of sideslip (AoS measurement, and an Attitude and Heading Reference System (AHRS that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS smoother, which consists of a forward pass Extended Kalman Filter (EKF and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS. It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly.

  16. FT-NIR spectroscopy and Whittaker smoother applied to joint analysis of duel-components for corn

    Science.gov (United States)

    Chen, Huazhou; Ai, Wu; Feng, Quanxi; Jia, Zhen; Song, Qiqing

    2014-01-01

    Protein and total fat are two ingredients to measure the quality of corn. The aim of this study is to evaluate the quality of corn by the dual-component join determination through Fourier transform near infrared (FT-NIR) spectroscopic analysis. The calibration models were established by the systematic study performed respectively in the four regions of the whole range, the second overtone, the first overtone, and the combination. Whittaker smoother was introduced as an attractive alternative data preprocessing method. With the optimized parameters, Whittaker smoother indicates its priority for improving modeling results in any of the four regions. The predictive abilities were compared between the joint analysis of protein and total fat and the separate analysis of each single component by partial least squares (PLS) modeling. The uncertainty in parameter was further estimated for the linear models. It is suggested that the joint analysis of dual-component always leads to better predictive results, and also provided good evaluation results for the independent validation samples. For the joint analysis, the optimal region for protein was the combination (5400-4000 cm-1), and the optimal region for total fat was the first overtone (7200-5400 cm-1). The optimal PLS models also provided appreciate predictive performance for both protein and total fat. And the parameter uncertainty determination provided an acceptable estimate of the measured uncertainty for the FT-NIR analysis of corn. In general, the joint analysis of dual-component is a better strategy for FT-NIR analysis of corn, and it is hoped to be tested for other objects.

  17. Motivated explanation

    Science.gov (United States)

    Patterson, Richard; Operskalski, Joachim T.; Barbey, Aron K.

    2015-01-01

    Although motivation is a well-established field of study in its own right, and has been fruitfully studied in connection with attribution theory and belief formation under the heading of “motivated thinking,” its powerful and pervasive influence on specifically explanatory processes is less well explored. Where one has a strong motivation to understand some event correctly, one is thereby motivated to adhere as best one can to normative or “epistemic” criteria for correct or accurate explanation, even if one does not consciously formulate or apply such criteria. By contrast, many of our motivations to explain introduce bias into the processes involved in generating, evaluating, or giving explanations. Non-epistemic explanatory motivations, or following Kunda's usage, “directional” motivations, include self-justification, resolution of cognitive dissonance, deliberate deception, teaching, and many more. Some of these motivations lead to the relaxation or violation of epistemic norms; others enhance epistemic motivation, so that one engages in more careful and thorough generational and evaluative processes. We propose that “real life” explanatory processes are often constrained by multiple goals, epistemic and directional, where these goals may mutually reinforce one another or may conflict, and where our explanations emerge as a matter of weighing and satisfying those goals. We review emerging evidence from psychology and neuroscience to support this framework and to elucidate the central role of motivation in human thought and explanation. PMID:26528166

  18. Curves and surfaces in the context of optometry. Part 1: Curves*

    OpenAIRE

    2005-01-01

    This paper introduces the differential geom-etry of curves in Euclidean 3-space, the motiva-tion being the writer’s belief that, despite their fundamental importance, curves are inadequate-ly treated in optometric educational programs. Curvature and torsion are defined along a curve. Two  numerical  examples  are  presented.  The fundamental theorem of curves is stated. The relationship of the geometry of varifocal lenses and curves known as involutes are discussed. A brief treatment of the t...

  19. A Complementary Note to 'A Lag-1 Smoother Approach to System-Error Estimation': The Intrinsic Limitations of Residual Diagnostics

    Science.gov (United States)

    Todling, Ricardo

    2015-01-01

    Recently, this author studied an approach to the estimation of system error based on combining observation residuals derived from a sequential filter and fixed lag-1 smoother. While extending the methodology to a variational formulation, experimenting with simple models and making sure consistency was found between the sequential and variational formulations, the limitations of the residual-based approach came clearly to the surface. This note uses the sequential assimilation application to simple nonlinear dynamics to highlight the issue. Only when some of the underlying error statistics are assumed known is it possible to estimate the unknown component. In general, when considerable uncertainties exist in the underlying statistics as a whole, attempts to obtain separate estimates of the various error covariances are bound to lead to misrepresentation of errors. The conclusions are particularly relevant to present-day attempts to estimate observation-error correlations from observation residual statistics. A brief illustration of the issue is also provided by comparing estimates of error correlations derived from a quasi-operational assimilation system and a corresponding Observing System Simulation Experiments framework.

  20. Estimating surface turbulent heat fluxes from land surface temperature and soil moisture observations using the particle batch smoother

    Science.gov (United States)

    Lu, Yang; Dong, Jianzhi; Steele-Dunne, Susan C.; van de Giesen, Nick

    2016-11-01

    Surface heat fluxes interact with the overlying atmosphere and play a crucial role in meteorology, hydrology, and climate change studies, but in situ observations are costly and difficult. It has been demonstrated that surface heat fluxes can be estimated from assimilation of land surface temperature (LST). One approach is to estimate a neutral bulk heat transfer coefficient (CHN) to scale the sum of turbulent heat fluxes, and an evaporative fraction (EF) that represents the partitioning between fluxes. Here the newly developed particle batch smoother (PBS) is implemented. The PBS makes no assumptions about the prior distributions and is therefore well-suited for non-Gaussian processes. It is also particularly advantageous for parameter estimation by tracking the entire prior distribution of parameters using Monte Carlo sampling. To improve the flux estimation on wet or densely vegetated surfaces, a simple soil moisture scheme is introduced to further constrain EF, and soil moisture observations are assimilated simultaneously. This methodology is implemented with the FIFE 1987 and 1988 data sets. Validation against observed fluxes indicates that assimilating LST using the PBS significantly improves the flux estimates at both daily and half-hourly timescales. When soil moisture is assimilated, the estimated EFs become more accurate, particularly when the surface heat flux partitioning is energy-limited. The feasibility of extending the methodology to use remote sensing observations is tested by limiting the number of LST observations. Results show that flux estimates are greatly improved after assimilating soil moisture, particularly when LST observations are sparse.

  1. Estimating soil moisture and soil thermal and hydraulic properties by assimilating soil temperatures using a particle batch smoother

    Science.gov (United States)

    Dong, Jianzhi; Steele-Dunne, Susan C.; Ochsner, Tyson E.; Giesen, Nick van de

    2016-05-01

    This study investigates the potential of estimating the soil moisture profile and the soil thermal and hydraulic properties by assimilating soil temperature at shallow depths using a particle batch smoother (PBS) using synthetic tests. Soil hydraulic properties influence the redistribution of soil moisture within the soil profile. Soil moisture, in turn, influences the soil thermal properties and surface energy balance through evaporation, and hence the soil heat transfer. Synthetic experiments were used to test the hypothesis that assimilating soil temperature observations could lead to improved estimates of soil hydraulic properties. We also compared different data assimilation strategies to investigate the added value of jointly estimating soil thermal and hydraulic properties in soil moisture profile estimation. Results show that both soil thermal and hydraulic properties can be estimated using shallow soil temperatures. Jointly updating soil hydraulic properties and soil states yields robust and accurate soil moisture estimates. Further improvement is observed when soil thermal properties were also estimated together with the soil hydraulic properties and soil states. Finally, we show that the inclusion of a tuning factor to prevent rapid fluctuations of parameter estimation, yields improved soil moisture, temperature, and thermal and hydraulic properties.

  2. GNSS/Low-Cost MEMS-INS Integration Using Variational Bayesian Adaptive Cubature Kalman Smoother and Ensemble Regularized ELM

    Directory of Open Access Journals (Sweden)

    Hassana Maigary Georges

    2015-01-01

    Full Text Available Among the inertial navigation system (INS devices used in land vehicle navigation (LVN, low-cost microelectromechanical systems (MEMS inertial sensors have received more interest for bridging global navigation satellites systems (GNSS signal failures because of their price and portability. Kalman filter (KF based GNSS/INS integration has been widely used to provide a robust solution to the navigation. However, its prediction model cannot give satisfactory results in the presence of colored and variational noise. In order to achieve reliable and accurate positional solution for LVN in urban areas surrounded by skyscrapers or under dense foliage and tunnels, a novel model combining variational Bayesian adaptive Kalman smoother (VB-ACKS as an alternative of KF and ensemble regularized extreme learning machine (ERELM for bridging global positioning systems outages is proposed. The ERELM is applied to reduce the fluctuating performance of GNSS during an outage. We show that a well-organized collection of predictors using ensemble learning yields a more accurate positional result when compared with conventional artificial neural network (ANN predictors. Experimental results show that the performance of VB-ACKS is more robust compared with KF solution, and the prediction of ERELM contains the smallest error compared with other ANN solutions.

  3. Motivated Explanation

    Directory of Open Access Journals (Sweden)

    Richard ePatterson

    2015-10-01

    Full Text Available Although motivation is a well-established field of study in its own right, and has been fruitfully studied in connection with attribution theory and belief formation under the heading of motivated thinking, its powerful and pervasive influence on explanatory processes is less well explored. Where one has a strong motivation to understand some event correctly, one is thereby motivated to adhere as best one can to normative or epistemic criteria for correct or accurate explanation, even if one does not consciously formulate or apply such criteria. By contrast, many of our motivations to explain introduce bias into the processes involved in generating, evaluating, or giving of explanations. Non-epistemic explanatory motivations, or (following Kunda’s usage, directional motivations, include self-justification, resolution of cognitive dissonance, deliberate deception, teaching, and many more. Some of these motivations lead to the relaxation or violation of epistemic norms, combined with an effort to preserve the appearance of accuracy; others enhance epistemic motivation, so that one engages in more careful and thorough generational and evaluative processes. In short, real life explanatory processes are often constrained by multiple goals, epistemic and directional, where these goals may mutually reinforce one another or may conflict, and where our explanations emerge as a matter of weighing and satisfying those goals. Our proposals are largely programmatic, although we do review a good deal of relevant behavioral and neurological evidence. Specifically, we recognize five generative processes, some of which cover further sub-processes, and six evaluative processes. All of these are potential points of entry for the influence of motivation. We then suggest in some detail how specific sorts of explanatory motivation interact with specific explanatory processes.

  4. Situating Motivation

    Science.gov (United States)

    Nolen, Susan Bobbitt; Horn, Ilana Seidel; Ward, Christopher J.

    2015-01-01

    This article describes a situative approach to studying motivation to learn in social contexts. We begin by contrasting this perspective to more prevalent psychological approaches to the study of motivation, describing epistemological and methodological differences that have constrained conversation between theoretical groups. We elaborate on…

  5. Motivational interviewing

    DEFF Research Database (Denmark)

    Karlsen, Kamilla; Humaidan, Peter; Sørensen, Lise H;

    2013-01-01

    This is a retrospective study to investigate whether motivational interviewing increases weight loss among obese or overweight women prior to fertility treatment. Women with body mass index (BMI) > 30 kg/m(2) approaching the Fertility Clinic, Regional Hospital Skive, were given advice about diet...... and physical activity with the purpose of weight loss. In addition, they were asked if they wanted to receive motivational interviewing. Among other data, age, height and weight were obtained. Main outcomes were weight loss measured in kg and decrease in BMI. We studied 187 women: 110 received sessions...... of motivational interviewing (intervention group, n = 110), 64 received motivational support by phone or e-mail only and 13 women did not wish any motivational support (control group, n = 77). The mean weight loss and decrease in BMI was greater in the intervention group compared with the control group (9.3 kg...

  6. Extraction of fetal ECG signal by an improved method using extended Kalman smoother framework from single channel abdominal ECG signal.

    Science.gov (United States)

    Panigrahy, D; Sahu, P K

    2017-02-16

    This paper proposes a five-stage based methodology to extract the fetal electrocardiogram (FECG) from the single channel abdominal ECG using differential evolution (DE) algorithm, extended Kalman smoother (EKS) and adaptive neuro fuzzy inference system (ANFIS) framework. The heart rate of the fetus can easily be detected after estimation of the fetal ECG signal. The abdominal ECG signal contains fetal ECG signal, maternal ECG component, and noise. To estimate the fetal ECG signal from the abdominal ECG signal, removal of the noise and the maternal ECG component presented in it is necessary. The pre-processing stage is used to remove the noise from the abdominal ECG signal. The EKS framework is used to estimate the maternal ECG signal from the abdominal ECG signal. The optimized parameters of the maternal ECG components are required to develop the state and measurement equation of the EKS framework. These optimized maternal ECG parameters are selected by the differential evolution algorithm. The relationship between the maternal ECG signal and the available maternal ECG component in the abdominal ECG signal is nonlinear. To estimate the actual maternal ECG component present in the abdominal ECG signal and also to recognize this nonlinear relationship the ANFIS is used. Inputs to the ANFIS framework are the output of EKS and the pre-processed abdominal ECG signal. The fetal ECG signal is computed by subtracting the output of ANFIS from the pre-processed abdominal ECG signal. Non-invasive fetal ECG database and set A of 2013 physionet/computing in cardiology challenge database (PCDB) are used for validation of the proposed methodology. The proposed methodology shows a sensitivity of 94.21%, accuracy of 90.66%, and positive predictive value of 96.05% from the non-invasive fetal ECG database. The proposed methodology also shows a sensitivity of 91.47%, accuracy of 84.89%, and positive predictive value of 92.18% from the set A of PCDB.

  7. Designing motivation

    DEFF Research Database (Denmark)

    are grappling with how to create motivating products, and as a primer for students who want a brief introduction to some of the relevant theories, findings and design interventions in these fields. The editor's introduction raises a number of issues encountered when we try to apply behavioural research......How can products be designed to change our habits for the better? What is some of the leading research that designers can draw on to create new systems that motivate people towards healthier behaviour? Designing Motivation is an edited collection of ‘industrialist cheat sheets’: 22 single......-page summaries of research articles relating to technology design, motivation, and behaviour change. Ranging across the fields of economics, sociology, design research and behavioural science, each summary draws out the design implications of the research. It is intended as a resource for designers who...

  8. Motivating pharmacists.

    Science.gov (United States)

    Donehew, G R

    1979-01-01

    Although pharmacists are developing interest in many types of pharmacy practice, they are still spending the bulk of their time in the prescription dispensing process. Any effort to provide motivation must consider the prescription dispensing process. The pharmacy literature includes only a few studies that dealt with pharmacists as people. The studies usually showed that pharmacists basically were unhappy with their jobs. In developing a motivational climate for pharmacists, pharmacy supervisors have several concepts to consider: the hierarchy of needs by Maslow; the expectancy theory by Hampton; the gygiene-motivator theory by Herzberg; and the Theory Y management approach by McGregor. Because pharmacists must be induced to enter and remain in an organization, supervisors should be aware of the need to use any technique available in developing a motivational climate.

  9. Designing motivation

    DEFF Research Database (Denmark)

    are grappling with how to create motivating products, and as a primer for students who want a brief introduction to some of the relevant theories, findings and design interventions in these fields. The editor's introduction raises a number of issues encountered when we try to apply behavioural research......How can products be designed to change our habits for the better? What is some of the leading research that designers can draw on to create new systems that motivate people towards healthier behaviour? Designing Motivation is an edited collection of ‘industrialist cheat sheets’: 22 single......-page summaries of research articles relating to technology design, motivation, and behaviour change. Ranging across the fields of economics, sociology, design research and behavioural science, each summary draws out the design implications of the research. It is intended as a resource for designers who...

  10. Drinking Motives

    DEFF Research Database (Denmark)

    Grunert, Klaus G; Rosendahl, Jacob; Andronikidis, Andreas I.

    2013-01-01

    , and quenching one’s thirst. The non-alcoholic products scoring low on functionality are coffee, tea, soft drinks, and energy drinks. Analysis of socio-demographic differences resulted in only a few effects. Men, lower education groups, and lower income groups are more likely to drink alcohol for reasons other......This chapter presents an analysis of what consumer in Europe drink and why they drink what they drink. The concept of drinking motives is developed and defined, and analysis of data on drinking motives shows that these can be grouped into two major classes: self-expressive and functional....... This distinction is universal and henceapplies across Europe. However, the importance of self-expressive as compared to functional motives, as well as the way in which these relate to different beverages, does differ across Europe. Both dimensions are relevant for the motives for drinking non-alcoholic drinks...

  11. Multiphasic growth curve analysis.

    NARCIS (Netherlands)

    Koops, W.J.

    1986-01-01

    Application of a multiphasic growth curve is demonstrated with 4 data sets, adopted from literature. The growth curve used is a summation of n logistic growth functions. Human height growth curves of this type are known as "double logistic" (n = 2) and "triple logistic" (n = 3) growth curves (Bock

  12. Employee Motivation

    Science.gov (United States)

    Goodman, Charles H.

    1971-01-01

    Motivation is an area which has received some systematic psychological study only in the past seventy years. It is the purpose of this article to explore and examine some of the knowledge that has been acquired and to see how this knowledge may be applied. (24 references) (Author/NH)

  13. Spinal curves (image)

    Science.gov (United States)

    There are four natural curves in the spinal column. The cervical, thoracic, lumbar, and sacral curvature. The curves, along with the intervertebral disks, help to absorb and distribute stresses that occur from everyday activities such as walking or from ...

  14. Contractibility of curves

    Directory of Open Access Journals (Sweden)

    Janusz Charatonik

    1991-11-01

    Full Text Available Results concerning contractibility of curves (equivalently: of dendroids are collected and discussed in the paper. Interrelations tetween various conditions which are either sufficient or necessary for a curve to be contractible are studied.

  15. Parametrizing Algebraic Curves

    OpenAIRE

    Lemmermeyer, Franz

    2011-01-01

    We present the technique of parametrization of plane algebraic curves from a number theorist's point of view and present Kapferer's simple and beautiful (but little known) proof that nonsingular curves of degree > 2 cannot be parametrized by rational functions.

  16. Accelerated dynamic cardiac MRI exploiting sparse-Kalman-smoother self-calibration and reconstruction (k  -  t SPARKS).

    Science.gov (United States)

    Park, Suhyung; Park, Jaeseok

    2015-05-07

    Accelerated dynamic MRI, which exploits spatiotemporal redundancies in k  -  t space and coil dimension, has been widely used to reduce the number of signal encoding and thus increase imaging efficiency with minimal loss of image quality. Nonetheless, particularly in cardiac MRI it still suffers from artifacts and amplified noise in the presence of time-drifting coil sensitivity due to relative motion between coil and subject (e.g. free breathing). Furthermore, a substantial number of additional calibrating signals is to be acquired to warrant accurate calibration of coil sensitivity. In this work, we propose a novel, accelerated dynamic cardiac MRI with sparse-Kalman-smoother self-calibration and reconstruction (k  -  t SPARKS), which is robust to time-varying coil sensitivity even with a small number of calibrating signals. The proposed k  -  t SPARKS incorporates Kalman-smoother self-calibration in k  -  t space and sparse signal recovery in x  -   f space into a single optimization problem, leading to iterative, joint estimation of time-varying convolution kernels and missing signals in k  -  t space. In the Kalman-smoother calibration, motion-induced uncertainties over the entire time frames were included in modeling state transition while a coil-dependent noise statistic in describing measurement process. The sparse signal recovery iteratively alternates with the self-calibration to tackle the ill-conditioning problem potentially resulting from insufficient calibrating signals. Simulations and experiments were performed using both the proposed and conventional methods for comparison, revealing that the proposed k  -  t SPARKS yields higher signal-to-error ratio and superior temporal fidelity in both breath-hold and free-breathing cardiac applications over all reduction factors.

  17. LEARNER MOTIVATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Zheng Min(Maggie):Initiation of the discus-sion topicDear Mr.Ma,I’m very sorry for this late initia-tion of discussion topics.Just come from one countyof Inner Mongolia near the city of Chi Feng.There isreally a lack of competent teachers of English in ruralareas,and in astonishment I saw many who barelyspeak English teaches English in middle schools.Asfor the topic of discussion,I’d like to focus on learn-er’s motivation,which is a vital factor in successfullearning.It is well known that motivation is classi-fied by Gardner & Lambert(1972)into"integrative"and"instrumental"ones.Other categorization in-

  18. ECM using Edwards curves

    DEFF Research Database (Denmark)

    Bernstein, Daniel J.; Birkner, Peter; Lange, Tanja;

    2013-01-01

    This paper introduces EECM-MPFQ, a fast implementation of the elliptic-curve method of factoring integers. EECM-MPFQ uses fewer modular multiplications than the well-known GMP-ECM software, takes less time than GMP-ECM, and finds more primes than GMP-ECM. The main improvements above the modular......-arithmetic level are as follows: (1) use Edwards curves instead of Montgomery curves; (2) use extended Edwards coordinates; (3) use signed-sliding-window addition-subtraction chains; (4) batch primes to increase the window size; (5) choose curves with small parameters and base points; (6) choose curves with large...

  19. Phonon dispersion curves of CsCN

    Indian Academy of Sciences (India)

    N K Gaur; Preeti Singh; E G Rini; Jyotsna Galgale; R K Singh

    2004-08-01

    The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique.

  20. Motivation in Beyond Budgeting: A Motivational Paradox?

    DEFF Research Database (Denmark)

    Sandalgaard, Niels; Bukh, Per Nikolaj

    In this paper we discuss the role of motivation in relation to budgeting and we analyse how the Beyond Budgeting model functions compared with traditional budgeting. In the paper we focus on budget related motivation (and motivation in general) and conclude that the Beyond Budgeting model...... is a motivational paradox....

  1. Pencils on real curves

    CERN Document Server

    Coppens, Marc

    2011-01-01

    We consider coverings of real algebraic curves to real rational algebraic curves. We show the existence of such coverings having prescribed topological degree on the real locus. From those existence results we prove some results on Brill-Noether Theory for pencils on real curves. For coverings having topological degree 0 we introduce the covering number k and we prove the existence of coverings of degree 4 with prescribed covering number.

  2. JUMPING THE CURVE

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-01-01

    Full Text Available This paper explores the notion ofjump ing the curve,following from Handy 's S-curve onto a new curve with new rules policies and procedures. . It claims that the curve does not generally lie in wait but has to be invented by leadership. The focus of this paper is the identification (mathematically and inferentially ofthat point in time, known as the cusp in catastrophe theory, when it is time to change - pro-actively, pre-actively or reactively. These three scenarios are addressed separately and discussed in terms ofthe relevance ofeach.

  3. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  4. Tempo curves considered harmful

    NARCIS (Netherlands)

    Desain, P.; Honing, H.

    1993-01-01

    In the literature of musicology, computer music research and the psychology of music, timing or tempo measurements are mostly presented in the form of continuous curves. The notion of these tempo curves is dangerous, despite its widespread use, because it lulls its users into the false impression th

  5. Pairings on hyperelliptic curves

    CERN Document Server

    Balakrishnan, Jennifer; Chisholm, Sarah; Eisentraeger, Kirsten; Stange, Katherine; Teske, Edlyn

    2009-01-01

    We assemble and reorganize the recent work in the area of hyperelliptic pairings: We survey the research on constructing hyperelliptic curves suitable for pairing-based cryptography. We also showcase the hyperelliptic pairings proposed to date, and develop a unifying framework. We discuss the techniques used to optimize the pairing computation on hyperelliptic curves, and present many directions for further research.

  6. Retrospectives: Engel Curves

    National Research Council Canada - National Science Library

    Andreas Chai; Alessio Moneta

    2010-01-01

    ..., Professor of Economics, University of Illinois, Chicago, at jpersky@uic.edu jpersky@uic.edu.. Introduction Introduction Engel curves describe how household expenditure on particular goods or Engel curves describe how household expenditure on particular goods or services depends on household income. The name comes from the German st...

  7. Tornado-Shaped Curves

    Science.gov (United States)

    Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio

    2017-01-01

    In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.

  8. The curve shortening problem

    CERN Document Server

    Chou, Kai-Seng

    2001-01-01

    Although research in curve shortening flow has been very active for nearly 20 years, the results of those efforts have remained scattered throughout the literature. For the first time, The Curve Shortening Problem collects and illuminates those results in a comprehensive, rigorous, and self-contained account of the fundamental results.The authors present a complete treatment of the Gage-Hamilton theorem, a clear, detailed exposition of Grayson''s convexity theorem, a systematic discussion of invariant solutions, applications to the existence of simple closed geodesics on a surface, and a new, almost convexity theorem for the generalized curve shortening problem.Many questions regarding curve shortening remain outstanding. With its careful exposition and complete guide to the literature, The Curve Shortening Problem provides not only an outstanding starting point for graduate students and new investigations, but a superb reference that presents intriguing new results for those already active in the field.

  9. A curve shortening flow rule for closed embedded plane curves with a prescribed rate of change in enclosed area.

    Science.gov (United States)

    Dallaston, Michael C; McCue, Scott W

    2016-01-01

    Motivated by a problem from fluid mechanics, we consider a generalization of the standard curve shortening flow problem for a closed embedded plane curve such that the area enclosed by the curve is forced to decrease at a prescribed rate. Using formal asymptotic and numerical techniques, we derive possible extinction shapes as the curve contracts to a point, dependent on the rate of decreasing area; we find there is a wider class of extinction shapes than for standard curve shortening, for which initially simple closed curves are always asymptotically circular. We also provide numerical evidence that self-intersection is possible for non-convex initial conditions, distinguishing between pinch-off and coalescence of the curve interior.

  10. Learning Curve? Which One?

    Directory of Open Access Journals (Sweden)

    Paulo Prochno

    2004-07-01

    Full Text Available Learning curves have been studied for a long time. These studies provided strong support to the hypothesis that, as organizations produce more of a product, unit costs of production decrease at a decreasing rate (see Argote, 1999 for a comprehensive review of learning curve studies. But the organizational mechanisms that lead to these results are still underexplored. We know some drivers of learning curves (ADLER; CLARK, 1991; LAPRE et al., 2000, but we still lack a more detailed view of the organizational processes behind those curves. Through an ethnographic study, I bring a comprehensive account of the first year of operations of a new automotive plant, describing what was taking place on in the assembly area during the most relevant shifts of the learning curve. The emphasis is then on how learning occurs in that setting. My analysis suggests that the overall learning curve is in fact the result of an integration process that puts together several individual ongoing learning curves in different areas throughout the organization. In the end, I propose a model to understand the evolution of these learning processes and their supporting organizational mechanisms.

  11. Motivating the Knowledge Worker

    Science.gov (United States)

    2010-01-01

    Herzberg . The Two - factor Theory asserts that motivators and de-motivators are mutually exclusive sets of factors . This research supports...various theories of motivation and the data collected from this effort, the author developed a two -dimensional model of the factors that motivate... Theory X/ Theory Y Two - factor Theory Cognitive Evaluation Theory Operant Conditioning Protection Motivation Theory

  12. SRHA calibration curve

    Data.gov (United States)

    U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation. This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...

  13. ROBUST DECLINE CURVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sutawanir Darwis

    2012-05-01

    Full Text Available Empirical decline curve analysis of oil production data gives reasonable answer in hyperbolic type curves situations; however the methodology has limitations in fitting real historical production data in present of unusual observations due to the effect of the treatment to the well in order to increase production capacity. The development ofrobust least squares offers new possibilities in better fitting production data using declinecurve analysis by down weighting the unusual observations. This paper proposes a robustleast squares fitting lmRobMM approach to estimate the decline rate of daily production data and compares the results with reservoir simulation results. For case study, we usethe oil production data at TBA Field West Java. The results demonstrated that theapproach is suitable for decline curve fitting and offers a new insight in decline curve analysis in the present of unusual observations.

  14. Large Curved Surface Measurement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The measurement principle of large curved surface through theodolite industry survey system is introduced. Two methods are suggested with respect to the distribution range of curved surface error. The experiments show that the measurement precision can be up to 0.15mm with relative precision of 3×10-5. Finally, something needed paying attention to and the application aspects on theodolite industry survey system are given.

  15. Counting curves on surfaces

    OpenAIRE

    2015-01-01

    In this paper we consider an elementary, and largely unexplored, combinatorial problem in low-dimensional topology. Consider a real 2-dimensional compact surface $S$, and fix a number of points $F$ on its boundary. We ask: how many configurations of disjoint arcs are there on $S$ whose boundary is $F$? We find that this enumerative problem, counting curves on surfaces, has a rich structure. For instance, we show that the curve counts obey an effective recursion, in the general framework of to...

  16. Arithmetic of Shimura curves

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This is the note for a series of lectures that the author gave at the Centre de Recerca Matemtica (CRM), Bellaterra, Barcelona, Spain on October 19–24, 2009. The aim is to give a comprehensive description of some recent work of the author and his students on generalisations of the Gross-Zagier formula, Euler systems on Shimura curves, and rational points on elliptic curves.

  17. Highly curved microchannel plates

    Science.gov (United States)

    Siegmund, O. H. W.; Cully, S.; Warren, J.; Gaines, G. A.; Priedhorsky, W.; Bloch, J.

    1990-01-01

    Several spherically curved microchannel plate (MCP) stack configurations were studied as part of an ongoing astrophysical detector development program, and as part of the development of the ALEXIS satellite payload. MCP pairs with surface radii of curvature as small as 7 cm, and diameters up to 46 mm have been evaluated. The experiments show that the gain (greater than 1.5 x 10 exp 7) and background characteristics (about 0.5 events/sq cm per sec) of highly curved MCP stacks are in general equivalent to the performance achieved with flat MCP stacks of similar configuration. However, gain variations across the curved MCP's due to variations in the channel length to diameter ratio are observed. The overall pulse height distribution of a highly curved surface MCP stack (greater than 50 percent FWHM) is thus broader than its flat counterpart (less than 30 percent). Preconditioning of curved MCP stacks gives comparable results to flat MCP stacks, but it also decreases the overall gain variations. Flat fields of curved MCP stacks have the same general characteristics as flat MCP stacks.

  18. Approximation by planar elastic curves

    DEFF Research Database (Denmark)

    Brander, David; Gravesen, Jens; Nørbjerg, Toke Bjerge

    2016-01-01

    We give an algorithm for approximating a given plane curve segment by a planar elastic curve. The method depends on an analytic representation of the space of elastic curve segments, together with a geometric method for obtaining a good initial guess for the approximating curve. A gradient......-driven optimization is then used to find the approximating elastic curve....

  19. Moduli of Trigonal Curves

    CERN Document Server

    Stankova-Frenkel, Z E

    1997-01-01

    We study the moduli of trigonal curves. We establish the exact upper bound of ${36(g+1)}/(5g+1)$ for the slope of trigonal fibrations. Here, the slope of any fibration $X\\to B$ of stable curves with smooth general member is the ratio Hodge class $\\lambda$ on the moduli space $\\bar{\\mathfrak{M}}_g$ to the base $B$. We associate to a trigonal family $X$ a canonical rank two vector bundle $V$, and show that for Bogomolov-semistable $V$ the slope satisfies the stronger inequality ${\\delta_B}/{\\lambda_B}\\leq 7+{6}/{g}$. We further describe the rational Picard group of the {trigonal} locus $\\bar{\\mathfrak T}_g$ in the moduli space $\\bar{\\mathfrak{M}}_g$ of genus $g$ curves. In the even genus case, we interpret the above Bogomolov semistability condition in terms of the so-called Maroni divisor in $\\bar{\\mathfrak T}_g$.

  20. Power Curve Measurements REWS

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here, the refere......This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here......, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...

  1. The sales learning curve.

    Science.gov (United States)

    Leslie, Mark; Holloway, Charles A

    2006-01-01

    When a company launches a new product into a new market, the temptation is to immediately ramp up sales force capacity to gain customers as quickly as possible. But hiring a full sales force too early just causes the firm to burn through cash and fail to meet revenue expectations. Before it can sell an innovative product efficiently, the entire organization needs to learn how customers will acquire and use it, a process the authors call the sales learning curve. The concept of a learning curve is well understood in manufacturing. Employees transfer knowledge and experience back and forth between the production line and purchasing, manufacturing, engineering, planning, and operations. The sales learning curve unfolds similarly through the give-and-take between the company--marketing, sales, product support, and product development--and its customers. As customers adopt the product, the firm modifies both the offering and the processes associated with making and selling it. Progress along the manufacturing curve is measured by tracking cost per unit: The more a firm learns about the manufacturing process, the more efficient it becomes, and the lower the unit cost goes. Progress along the sales learning curve is measured in an analogous way: The more a company learns about the sales process, the more efficient it becomes at selling, and the higher the sales yield. As the sales yield increases, the sales learning process unfolds in three distinct phases--initiation, transition, and execution. Each phase requires a different size--and kind--of sales force and represents a different stage in a company's production, marketing, and sales strategies. Adjusting those strategies as the firm progresses along the sales learning curve allows managers to plan resource allocation more accurately, set appropriate expectations, avoid disastrous cash shortfalls, and reduce both the time and money required to turn a profit.

  2. Algebraic curves and cryptography

    CERN Document Server

    Murty, V Kumar

    2010-01-01

    It is by now a well-known paradigm that public-key cryptosystems can be built using finite Abelian groups and that algebraic geometry provides a supply of such groups through Abelian varieties over finite fields. Of special interest are the Abelian varieties that are Jacobians of algebraic curves. All of the articles in this volume are centered on the theme of point counting and explicit arithmetic on the Jacobians of curves over finite fields. The topics covered include Schoof's \\ell-adic point counting algorithm, the p-adic algorithms of Kedlaya and Denef-Vercauteren, explicit arithmetic on

  3. Power Curve Measurements REWS

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Villanueva, Héctor

    This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here......, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...

  4. Power curve investigation

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Vesth, Allan

    are not performed according to IEC 61400-12-1 [1]. Therefore, the results presented in this report cannot be considered a power curve according to the reference standard, and are referred to as “power curve investigation” instead. The measurements have been performed by a customer and the data analysis has been......This report describes the analysis carried out with data from a given turbine in a wind farm and a chosen period. The purpose of the analysis is to correlate the power output of the wind turbine to the wind speed measured by a nacelle-mounted anemometer. The measurements and analysis...

  5. Paths of algebraic hyperbolic curves

    Institute of Scientific and Technical Information of China (English)

    Ya-juan LI; Li-zheng LU; Guo-zhao WANG

    2008-01-01

    Cubic algebraic hyperbolic (AH) Bezier curves and AH spline curves are defined with a positive parameter α in the space spanned by {1, t, sinht, cosht}. Modifying the value of α yields a family of AH Bezier or spline curves with the family parameter α. For a fixed point on the original curve, it will move on a defined curve called "path of AH curve" (AH Bezier and AH spline curves) when α changes. We describe the geometric effects of the paths and give a method to specify a curve passing through a given point.

  6. Motivation programmes of organizations

    OpenAIRE

    Pízová, Tereza

    2008-01-01

    The Bachelor Thesis "'Motivation Programmes of Organizations" focuses on an extremely important area within personnel management. Employee motivation is crucial to the effective operation of businesses. Motivation programmes assist in increasing and maintaining employee motivation and demonstrate an organization's interest in its employees. This piece is on one hand concerned with theoretical foundations of motivation, describing theories and concepts important to the area of human behaviour ...

  7. Nacelle lidar power curve

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  8. Graphs, Curves and Dynamics

    NARCIS (Netherlands)

    Kool, J.

    2013-01-01

    This thesis has three main subjects. The first subject is Measure-theoretic rigidity of Mumford Curves. One can describe isomorphism of two compact hyperbolic Riemann surfaces of the same genus by a measure-theoretic property: a chosen isomorphism of their fundamental groups corresponds to a homeomo

  9. Power Curve Measurements

    DEFF Research Database (Denmark)

    Vesth, Allan; Kock, Carsten Weber

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present anal...

  10. Power Curve Measurements

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  11. Power Curve Measurements FGW

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Villanueva, Héctor

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  12. Fitting a Gompertz curve

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans)

    1994-01-01

    textabstractIn this paper, a simple Gompertz curve-fitting procedure is proposed. Its advantages include the facts that the stability of the saturation level over the sample period can be checked, and that no knowledge of its value is necessary for forecasting. An application to forecasting the stoc

  13. Gompertz curves with seasonality

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans)

    1994-01-01

    textabstractThis paper considers an extension of the usual Gompertz curve by allowing the parameters to vary over the seasons. This means that, for example, saturation levels can be different over the year. An estimation and testing method is proposed and illustrated with an example.

  14. Power Curve Measurements

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  15. Power Curve Measurements, FGW

    DEFF Research Database (Denmark)

    Vesth, Allan; Yordanova, Ginka

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...

  16. Graphing Polar Curves

    Science.gov (United States)

    Lawes, Jonathan F.

    2013-01-01

    Graphing polar curves typically involves a combination of three traditional techniques, all of which can be time-consuming and tedious. However, an alternative method--graphing the polar function on a rectangular plane--simplifies graphing, increases student understanding of the polar coordinate system, and reinforces graphing techniques learned…

  17. Power Curve Measurements, REWS

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here, the refere...

  18. Power Curve Measurements

    DEFF Research Database (Denmark)

    Federici, Paolo; Kock, Carsten Weber

    This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...

  19. Straightening Out Learning Curves

    Science.gov (United States)

    Corlett, E. N.; Morecombe, V. J.

    1970-01-01

    The basic mathematical theory behind learning curves is explained, together with implications for clerical and industrial training, evaluation of skill development, and prediction of future performance. Brief studies of textile worker and typist training are presented to illustrate such concepts as the reduction fraction (a consistent decrease in…

  20. Carbon Lorenz Curves

    NARCIS (Netherlands)

    Groot, L.F.M.

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across

  1. Power Curve Measurements

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Federici, Paolo

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....

  2. Power Curve Measurements, FGW

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....

  3. Recombination Effects on Supernovae Light-Curves

    CERN Document Server

    Goldfriend, Tomer; Sari, Re'em

    2014-01-01

    Supernovae of type IIP are marked by the long plateau seen in their optical light curves. The plateau is believed to be the result of a recombination wave that propagates through the outflowing massive hydrogen envelope. Here, we analytically investigate the transition from a fully ionized envelope to a partially recombined one and its effects on the SN light curve. The motivation is to establish the underlying processes which dominate the evolution at late times when recombination takes place in the envelope, yet early enough so that $^{56}$Ni decay is a negligible source of energy. We assume a simple, yet adequate, hydrodynamic profile of the envelope and study the mechanisms which dominate the energy emission and the observed temperature. We consider the diffusion of photons through the envelope while analyzing the ionization fraction and the coupling between radiation and gas. We find that once recombination starts, the observed temperature decreases slowly in time. However, in a typical red supergiant (R...

  4. Pure motives with representable Chow groups

    CERN Document Server

    Vial, Charles

    2011-01-01

    Let $k$ be an algebraically closed field. We show using Kahn's and Sujatha's theory of birational motives that a Chow motive over $k$ whose Chow groups are all representable belongs to the full and thick subcategory of motives generated by the twisted motives of curves. -- Motifs purs dont les groupes de Chow sont repr\\'esentables. Soit $k$ un corps alg\\'ebriquement clos. Nous prouvons, en nous servant de la th\\'eorie des motifs birationnels d\\'evelopp\\'ee par Kahn et Sujatha, qu'un motif de Chow d\\'efini sur $k$ dont les groupes de Chow sont tous repr\\'esentables appartient \\`a la sous-cat\\'egorie pleine et \\'epaisse des motifs engendr\\'ee par les motifs de courbes tordus.

  5. Command and motivation

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher; Hvidtved, Johan; Andersen, Lotte Bøgh

    2014-01-01

    Motivated employees are crucial to organizations, but external interventions such as command systems and financial incentives may decrease motivation. If these external interventions are perceived to be controlling, they are expected to crowd out intrinsic motivation, and this may also apply...... to other types of autonomous motivation such as public service motivation. The perception of external interventions is thus expected to be vital. This article investigates how the perception of a specific command system (obligatory student plans) is associated with intrinsic motivation and public service...... motivation. Using a dataset with 3,230 school teachers in Denmark, a structural equation model shows that the perception of obligatory student plans as controlling is negatively associated with all of the investigated types of employee motivation, supporting that motivation crowding can occur....

  6. Carbon Lorenz Curves

    Energy Technology Data Exchange (ETDEWEB)

    Groot, L. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)

    2008-11-15

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across countries. These tools allow policy-makers and the general public to grasp at a single glance the impact of conventional distribution rules such as equal caps or grandfathering, or more sophisticated ones, on the distribution of greenhouse gas emissions. Second, using the Samuelson rule for the optimal provision of a public good, the Pareto-optimal distribution of carbon emissions is compared with the distribution that follows if countries follow Nash-Cournot abatement strategies. It is shown that the Pareto-optimal distribution under the Samuelson rule can be approximated by the equal cap division, represented by the diagonal in the Lorenz curve diagram.

  7. Managing curved canals

    Directory of Open Access Journals (Sweden)

    Iram Ansari

    2012-01-01

    Full Text Available Dilaceration is the result of a developmental anomaly in which there has been an abrupt change in the axial inclination between the crown and the root of a tooth. Dilaceration can be seen in both the permanent and deciduous dentitions, and is more commonly found in posterior teeth and in maxilla. Periapical radiographs are the most appropriate way to diagnose the presence of root dilacerations. The controlled regularly tapered preparation of the curved canals is the ultimate challenge in endodontics. Careful and meticulous technique will yield a safe and sufficient enlargement of the curved canals. This article gives a review of the literature and three interesting case reports of root dilacerations.

  8. LCC: Light Curves Classifier

    Science.gov (United States)

    Vo, Martin

    2017-08-01

    Light Curves Classifier uses data mining and machine learning to obtain and classify desired objects. This task can be accomplished by attributes of light curves or any time series, including shapes, histograms, or variograms, or by other available information about the inspected objects, such as color indices, temperatures, and abundances. After specifying features which describe the objects to be searched, the software trains on a given training sample, and can then be used for unsupervised clustering for visualizing the natural separation of the sample. The package can be also used for automatic tuning parameters of used methods (for example, number of hidden neurons or binning ratio). Trained classifiers can be used for filtering outputs from astronomical databases or data stored locally. The Light Curve Classifier can also be used for simple downloading of light curves and all available information of queried stars. It natively can connect to OgleII, OgleIII, ASAS, CoRoT, Kepler, Catalina and MACHO, and new connectors or descriptors can be implemented. In addition to direct usage of the package and command line UI, the program can be used through a web interface. Users can create jobs for ”training” methods on given objects, querying databases and filtering outputs by trained filters. Preimplemented descriptors, classifier and connectors can be picked by simple clicks and their parameters can be tuned by giving ranges of these values. All combinations are then calculated and the best one is used for creating the filter. Natural separation of the data can be visualized by unsupervised clustering.

  9. Dynamics of curved fronts

    CERN Document Server

    Pelce, Pierre

    1989-01-01

    In recent years, much progress has been made in the understanding of interface dynamics of various systems: hydrodynamics, crystal growth, chemical reactions, and combustion. Dynamics of Curved Fronts is an important contribution to this field and will be an indispensable reference work for researchers and graduate students in physics, applied mathematics, and chemical engineering. The book consist of a 100 page introduction by the editor and 33 seminal articles from various disciplines.

  10. Estimating Corporate Yield Curves

    OpenAIRE

    Antionio Diaz; Frank Skinner

    2001-01-01

    This paper represents the first study of retail deposit spreads of UK financial institutions using stochastic interest rate modelling and the market comparable approach. By replicating quoted fixed deposit rates using the Black Derman and Toy (1990) stochastic interest rate model, we find that the spread between fixed and variable rates of interest can be modeled (and priced) using an interest rate swap analogy. We also find that we can estimate an individual bank deposit yield curve as a spr...

  11. Atypical Light Curves

    CERN Document Server

    Steenwyk, Steven D; Molnar, Lawrence A

    2013-01-01

    We have identified some two-hundred new variable stars in a systematic study of a data archive obtained with the Calvin-Rehoboth observatory. Of these, we present five close binaries showing behaviors presumably due to star spots or other magnetic activity. For context, we first present two new RS CVn systems whose behavior can be readily attribute to star spots. Then we present three new close binary systems that are rather atypical, with light curves that are changing over time in ways not easily understood in terms of star spot activity generally associated with magnetically active binary systems called RS CVn systems. Two of these three are contact binaries that exhibit gradual changes in average brightness without noticeable changes in light curve shape. A third system has shown such large changes in light curve morphology that we speculate this may be a rare instance of a system that transitions back and forth between contact and noncontact configurations, perhaps driven by magnetic cycles in at least o...

  12. Motivating pharmacy employees.

    Science.gov (United States)

    White, S J; Generali, J A

    1984-07-01

    Concepts from theories of motivation are used to suggest methods for improving the motivational environment of hospital pharmacy departments. Motivation--the state of being stimulated to take action to achieve a goal or to satisfy a need--comes from within individuals, but hospital pharmacy managers can facilitate motivation by structuring the work environment so that it satisfies employees' needs. Concepts from several theories of motivation are discussed, including McGregor's theory X and theory Y assumptions, Maslow's hierarchy of needs theory, Herzberg's motivation hygiene theory, and Massey's value system theory. Concepts from the Japanese style of management that can be used to facilitate motivation, such as quality circles, also are described. The autocratic, participative, and laissez faire styles of leadership are discussed in the context of the motivation theories, and suggested applications of theoretical concepts to practice are presented.

  13. Understanding Employee Motivation.

    Science.gov (United States)

    Lindner, James R.

    1998-01-01

    Extension employees (n=23) ranked the following as the most important motivational factors: interesting work, good wages, appreciation, job security, and good working conditions. The findings were related to theories of motivation formulated by Herzberg, Adams, and Vroom. (SK)

  14. Understanding Employee Motivation.

    Science.gov (United States)

    Lindner, James R.

    1998-01-01

    Extension employees (n=23) ranked the following as the most important motivational factors: interesting work, good wages, appreciation, job security, and good working conditions. The findings were related to theories of motivation formulated by Herzberg, Adams, and Vroom. (SK)

  15. What Motivates Trainees?

    Science.gov (United States)

    Cohen, Debra J.

    1990-01-01

    A study of five organizations examined employee motivation regarding the pretraining environment. Findings support the assumption that employees will be more motivated of supervisors are supportive and if they view attendance as voluntary. (JOW)

  16. Unges motivation i udskolingen

    DEFF Research Database (Denmark)

    Pless, Mette; Katznelson, Noemi; Hjort-Madsen, Peder

    Om hvordan de unge i udskolingen skaber lyst og motivation for læring. Med afsnit om hvad motivation er, hvordan den fremmes hos unge og kombineres med et liv udenfor skolen......Om hvordan de unge i udskolingen skaber lyst og motivation for læring. Med afsnit om hvad motivation er, hvordan den fremmes hos unge og kombineres med et liv udenfor skolen...

  17. [Motivational interview: supporting change].

    Science.gov (United States)

    Fond, Guillaume; Ducasse, Déborah

    2015-01-01

    The motivational interview aims to help patients to resolve their ambivalence regarding problematic behaviors and to guide them into change. It differs from other therapeutic approaches mainly through the attitude of the therapist. In motivational interviewing, the therapist defends the statu quo. By reactance, the patient defends the change and enhance her/his motivation. This article provides a summary of the other concepts of motivational interviewing and its applications in the psychiatric daily practice.

  18. Learner motivation and interest

    OpenAIRE

    Daskalovska, Nina; Koleva Gudeva, Liljana; Ivanovska, Biljana

    2012-01-01

    There are a lot of factors which influence success in learning. However, one of the most important factors is the learner’s motivation to reach the desired goals. Research and experience show that learners with strong motivation can achieve a lot regardless of circumstances. Studies of motivation in second language learning have led to several distinctions, one of which is the distinction between integrative and instrumental motivation. According to this distinction, some learners are motivat...

  19. Learner motivation and interest

    OpenAIRE

    Daskalovska, Nina; Koleva Gudeva, Liljana; Ivanovska, Biljana

    2012-01-01

    There are a lot of factors which influence success in learning. However, one of the most important factors is the learner’s motivation to reach the desired goals. Research and experience show that learners with strong motivation can achieve a lot regardless of circumstances. Studies of motivation in second language learning have led to several distinctions, one of which is the distinction between integrative and instrumental motivation. According to this distinction, some learners are motivat...

  20. Curves and surfaces in the context of optometry. Part 1: Curves*

    Directory of Open Access Journals (Sweden)

    W.F. Harris

    2005-01-01

    Full Text Available This paper introduces the differential geom-etry of curves in Euclidean 3-space, the motiva-tion being the writer’s belief that, despite their fundamental importance, curves are inadequate-ly treated in optometric educational programs. Curvature and torsion are defined along a curve. Two  numerical  examples  are  presented.  The fundamental theorem of curves is stated. The relationship of the geometry of varifocal lenses and curves known as involutes are discussed. A brief treatment of the theory of contact is given with  suggestions  of  applications  in  contact between  spectacle  lenses  and  frames,  contact lenses and corneas (including orthokeratology, intra-ocular lenses and structures in the eye, and spectacle frames and the face.

  1. Curved PVDF airborne transducer.

    Science.gov (United States)

    Wang, H; Toda, M

    1999-01-01

    In the application of airborne ultrasonic ranging measurement, a partially cylindrical (curved) PVDF transducer can effectively couple ultrasound into the air and generate strong sound pressure. Because of its geometrical features, the ultrasound beam angles of a curved PVDF transducer can be unsymmetrical (i.e., broad horizontally and narrow vertically). This feature is desired in some applications. In this work, a curved PVDF air transducer is investigated both theoretically and experimentally. Two resonances were observed in this transducer. They are length extensional mode and flexural bending mode. Surface vibration profiles of these two modes were measured by a laser vibrometer. It was found from the experiment that the surface vibration was not uniform along the curvature direction for both vibration modes. Theoretical calculations based on a model developed in this work confirmed the experimental results. Two displacement peaks were found in the piezoelectric active direction of PVDF film for the length extensional mode; three peaks were found for the flexural bending mode. The observed peak positions were in good agreement with the calculation results. Transient surface displacement measurements revealed that vibration peaks were in phase for the length extensional mode and out of phase for the flexural bending mode. Therefore, the length extensional mode can generate a stronger ultrasound wave than the flexural bending mode. The resonance frequencies and vibration amplitudes of the two modes strongly depend on the structure parameters as well as the material properties. For the transducer design, the theoretical model developed in this work can be used to optimize the ultrasound performance.

  2. Magnetism in curved geometries

    Science.gov (United States)

    Streubel, Robert; Fischer, Peter; Kronast, Florian; Kravchuk, Volodymyr P.; Sheka, Denis D.; Gaididei, Yuri; Schmidt, Oliver G.; Makarov, Denys

    2016-09-01

    Extending planar two-dimensional structures into the three-dimensional space has become a general trend in multiple disciplines, including electronics, photonics, plasmonics and magnetics. This approach provides means to modify conventional or to launch novel functionalities by tailoring the geometry of an object, e.g. its local curvature. In a generic electronic system, curvature results in the appearance of scalar and vector geometric potentials inducing anisotropic and chiral effects. In the specific case of magnetism, even in the simplest case of a curved anisotropic Heisenberg magnet, the curvilinear geometry manifests two exchange-driven interactions, namely effective anisotropy and antisymmetric exchange, i.e. Dzyaloshinskii-Moriya-like interaction. As a consequence, a family of novel curvature-driven effects emerges, which includes magnetochiral effects and topologically induced magnetization patterning, resulting in theoretically predicted unlimited domain wall velocities, chirality symmetry breaking and Cherenkov-like effects for magnons. The broad range of altered physical properties makes these curved architectures appealing in view of fundamental research on e.g. skyrmionic systems, magnonic crystals or exotic spin configurations. In addition to these rich physics, the application potential of three-dimensionally shaped objects is currently being explored as magnetic field sensorics for magnetofluidic applications, spin-wave filters, advanced magneto-encephalography devices for diagnosis of epilepsy or for energy-efficient racetrack memory devices. These recent developments ranging from theoretical predictions over fabrication of three-dimensionally curved magnetic thin films, hollow cylinders or wires, to their characterization using integral means as well as the development of advanced tomography approaches are in the focus of this review.

  3. Personlighed og motivation

    DEFF Research Database (Denmark)

    Olsen, Jan Brødslev

    2017-01-01

    ses som forskelle i deres personlighed og i deres motivation. Kapitlet er opbygget således, at ganske kort præciseres først de to begreber, personlighed og motivation, hvorefter udvalgte teoretiske perspektiver på personlighed og motivation tages op. Til sammen vil disse bidrage til at besvare...

  4. Motivation, Management, and Performance.

    Science.gov (United States)

    Olmstead, Joseph A.

    There is an increasing interest today in the ways in which human motivation contributes to the productivity and performance of personnel. This early study of motivation management emphasizes that the organizational environment is a principal determinant of the quality of employee motivation. Concrete considerations in the management of motivation…

  5. Understanding Student Motivation

    Science.gov (United States)

    Seifert, Timothy

    2004-01-01

    Contemporary theories of academic motivation seek to explain students' behaviours in academic settings. While each theory seems to possess its own constructs and unique explanations, these theories are actually closely tied together. In this theoretical study of motivation, several theories of motivation were described and an underlying theme of…

  6. Motivator-manager.

    Science.gov (United States)

    McDonald, Angelic P

    2009-01-01

    The radiologic career field has undergone radical changes in technology, regulatory compliance, and customer expectation.These changes often require dramatic alterations to processes,which can break down communication, create stress, and have a negative effect on department productivity. Motivation itself is a frequently analyzed and reported topic in professional publications. For this purpose, this literature review specifically researches motivation as identified by radiology administrators through Radiology Management. Three key elements surfaced as those with the most impact: (1) motivation is an intrinsic factor which can be influenced but not created, (2) clear attainable goals are an essential component of motivation,and (3) motivation begins with identification of employee needs.

  7. Maintaining Learners’Motivation

    Institute of Scientific and Technical Information of China (English)

    SI Zi-han

    2015-01-01

    Foreign language learning is a complex process and its success is determined by a variety of factors. The prime one of them is motivation ,which, as everyone knows, could be controlled by external forces so as to be taken advantage of. Motivation could prompt the learner to have his own learning goals and let him finish his learning task autonomously. All of that shows the im⁃portance of maintaining learners’motivation. This paper will demonstrate not only the definition and the types of motivation, but al⁃so the methods that could be used to stimulate and maintain the motivation.

  8. Narcissism as motive.

    Science.gov (United States)

    Meissner, W W

    2008-07-01

    This essay proposes replacing the traditional concept of narcissism as derived from the theory of drives with a concept of narcissism that is concerned with motives and their correlative meanings-specifically, motives connected to self-organization, self-preservation, self-cohesion, self-valuation, and self-esteem. The reasons for and the metapsychological underpinnings of a motivationally based theory are discussed. This revised motivational view proposes that narcissistic dynamics can be preserved and articulated in exclusively motivational terms. Developmental aspects are explored, including formation and functioning of the ego ideal and self-esteem regulation. Implications for psychoanalytic technique are suggested in discussions of case material.

  9. Occupational safety motivation

    DEFF Research Database (Denmark)

    Pedersen, Louise; Kines, Pete

    2010-01-01

    . At the same time many motivation questionnaire items are seldom founded on theory and/or do not account for the theories’ ontological and epistemological differences, e.g. of how knowledge, attitude and action are related. Present questionnaire items tap into occupational safety motivation in asking whether...... or not respondents ‘are’ motivated and whether they feel that safety is important or worthwhile. Another important aspect is ‘what’ motivates workers to comply to and participate in safety. The aim of this article is to introduce a new theory-based occupational safety motivation scale which is validated......Background: Motivation is one of the most important factors for safety behaviour and for implementing change in general. However, theoretical and psychometric studies of safety performance have traditionally treated safety motivation, safety compliance and safety participation unidimensionally...

  10. Occupational safety motivation

    DEFF Research Database (Denmark)

    Pedersen, Louise; Kines, Pete

    2010-01-01

    . At the same time many motivation questionnaire items are seldom founded on theory and/or do not account for the theories’ ontological and epistemological differences, e.g. of how knowledge, attitude and action are related. Present questionnaire items tap into occupational safety motivation in asking whether...... or not respondents ‘are’ motivated and whether they feel that safety is important or worthwhile. Another important aspect is ‘what’ motivates workers to comply to and participate in safety. The aim of this article is to introduce a new theory-based occupational safety motivation scale which is validated......Background: Motivation is one of the most important factors for safety behaviour and for implementing change in general. However, theoretical and psychometric studies of safety performance have traditionally treated safety motivation, safety compliance and safety participation unidimensionally...

  11. Public Service Motivation

    Directory of Open Access Journals (Sweden)

    Raluca-Marilena Mihalcioiu

    2011-05-01

    Full Text Available Public Service Motivation concept was developed in North America and focuses on specific motivations of public servants, such as employee satisfaction, organizational commitment, reward preferences, organizational and individual performance. Other types of motivation, as financial consideration, are relevant but have less important influences with regard to this kind of work outcomes. This strengthen the assertion for a diversified motivational strategy, which affect various types of motivation, while not losing sight of the public value that one organization shows and therefore valuing public service motivation as a specific contribution to work outcomes. The concept has been increasingly applied in European public administration. This paper presents Status Quo of international Public Service Motivation research and locates in them empirical evidences from contries that are already working with this concept, like Austria. It also analyses implications for central questions of public management. The main focus of this article is general appropriateness and possible applications for Romanian public management research.

  12. Motivating Workers in Construction

    Directory of Open Access Journals (Sweden)

    Jason E. Barg

    2014-01-01

    Full Text Available The study of the motivation of construction workers is limited to a relatively small body of knowledge. Although there is considerable research available regarding motivation and productivity, few researchers have provided a comprehensive analysis on the motivation of construction workers. The research stated that productivity in construction has not improved compared to other industry sectors such as manufacturing. This trend has been echoed in publications throughout the past five decades, and suggested that motivation is one of the key factors impacting productivity. This paper offers a comprehensive review of the published work that directly links the key words—construction and motivation. The findings have been presented in five themes, that is, motivation models, environment and culture, incentives and empowerment, and worker management. This paper concludes with two methods suggested by previous researchers to improve motivation of construction workers: (1 relevant worker incentives (intrinsic or extrinsic and (2 improved management practices, specifically regarding communication with workers.

  13. Automating Recession Curve Displacement Recharge Estimation.

    Science.gov (United States)

    Smith, Brennan; Schwartz, Stuart

    2017-01-01

    Recharge estimation is an important and challenging element of groundwater management and resource sustainability. Many recharge estimation methods have been developed with varying data requirements, applicable to different spatial and temporal scales. The variability and inherent uncertainty in recharge estimation motivates the recommended use of multiple methods to estimate and bound regional recharge estimates. Despite the inherent limitations of using daily gauged streamflow, recession curve displacement methods provide a convenient first-order estimate as part of a multimethod hierarchical approach to estimate watershed-scale annual recharge. The implementation of recession curve displacement recharge estimation in the United States Geologic Survey (USGS) RORA program relies on the subjective, operator-specific selection of baseflow recession events to estimate a gauge-specific recession index. This paper presents a parametric algorithm that objectively automates this tedious, subjective process, parameterizing and automating the implementation of recession curve displacement. Results using the algorithm reproduce regional estimates of groundwater recharge from the USGS Appalachian Valley and Piedmont Regional Aquifer-System Analysis, with an average absolute error of less than 2%. The algorithm facilitates consistent, completely automated estimation of annual recharge that complements more rigorous data-intensive techniques for recharge estimation. © 2016, National Ground Water Association.

  14. Superfluids in Curved Spacetime

    CERN Document Server

    Villegas, Kristian Hauser A

    2015-01-01

    Superfluids under an intense gravitational field are typically found in neutron star and quark star cores. Most treatments of these superfluids, however, are done in a flat spacetime background. In this paper, the effect of spacetime curvature on superfluidity is investigated. An effective four-fermion interaction is derived by integrating out the mediating scalar field. The fermions interacting via the mediating gauge vector bosons is also discussed. Two possible cases are considered in the mean-field treatment: antifermion-fermion and fermion-fermion pairings. An effective action, quadratic in fermion field, and a self-consistent equation are derived for both cases. The effective Euclidean action and the matrix elements of the heat kernel operator, which are very useful in curved-spacetime QFT calculations, are derived for the fermion-fermion pairing. Finally, explicit numerical calculation of the gravitational correction to the pairing order parameter is performed for the scalar superfluid case. It is foun...

  15. Polymers in Curved Boxes

    CERN Document Server

    Yaman, K; Solis, F J; Witten, T A

    1996-01-01

    We apply results derived in other contexts for the spectrum of the Laplace operator in curved geometries to the study of an ideal polymer chain confined to a spherical annulus in arbitrary space dimension D and conclude that the free energy compared to its value for an uncurved box of the same thickness and volume, is lower when $D < 3$, stays the same when $D = 3$, and is higher when lowers the effective bending elasticity of the walls, and might induce spontaneous symmetry breaking, i.e. bending. (Actually, the above mentioned results show that {\\em {any}} shell in $D = 3$ induces this effect, except for a spherical shell). We compute the contribution of this effect to the bending rigidities in the Helfrich free energy expression.

  16. Evolutes of Hyperbolic Plane Curves

    Institute of Scientific and Technical Information of China (English)

    Shyuichi IZUMIYA; Dong He PEI; Takashi SANO; Erika TORII

    2004-01-01

    We define the notion of evolutes of curves in a hyperbolic plane and establish the relationships between singularities of these subjects and geometric invariants of curves under the action of the Lorentz group. We also describe how we can draw the picture of an evolute of a hyperbolic plane curve in the Poincar(e) disk.

  17. The Arithmetic of Elliptic Curves

    CERN Document Server

    Silverman, Joseph H

    2009-01-01

    Treats the arithmetic theory of elliptic curves in its modern formulation, through the use of basic algebraic number theory and algebraic geometry. This book discusses the necessary algebro-geometric results, and offers an exposition of the geometry of elliptic curves, and the formal group of an elliptic curve.

  18. Curved-Duct

    Directory of Open Access Journals (Sweden)

    Je Hyun Baekt

    2000-01-01

    Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.

  19. An introduction to motivic Hall algebras

    CERN Document Server

    Bridgeland, Tom

    2010-01-01

    We give an introduction to Joyce's construction of the motivic Hall algebra of coherent sheaves on a variety M. When M is a Calabi-Yau threefold we define a semi-classical integration map from a Poisson subalgebra of this Hall algebra to the ring of functions on a symplectic torus. This material will be used in arxiv:1002.4374 to prove some basic properties of Donaldson-Thomas curve-counting invariants on Calabi-Yau threefolds.

  20. Fabrication of a curved microlens array using double gray-scale digital maskless lithography

    Science.gov (United States)

    Luo, Ningning; Zhang, Zhimin

    2017-03-01

    Digital maskless lithography is considered to be a high-efficiency and low-cost approach for the fabrication of microstructures, but is limited by the gray scale capability of spatial light modulators. In this work, a novel method of double gray-scale digital maskless lithography is presented for forming a curved microlens array. The target exposure dose profile of the curved microlens array is first split into two individual 3D energy profiles, and then each 3D energy profile can be respectively realized by a single gray-scale digital lithography. Two gray-scale digital masks obtained by projection calculation are superposed on the substrate so as to realize the exposure dose profile of the curved microlens array. Thus, the effective steps that are achieved through the photoresist response to the modulated UV exposure are doubled, so a smoother profile with a steep gradient can be formed by the precise modulation of double gray-scale masks. As a result of the double gray-scale method, a curved microlens array with 183 micro lenslets on a 1024 µm  ×  768 µm spherical surface has been successfully fabricated.

  1. Foliations on the moduli space of curves, vanishing in cohomology, and Calogero-Moser curves

    CERN Document Server

    Grushevsky, Samuel

    2011-01-01

    Using meromorphic differentials with real periods, we show that a certain tautological homology class on the moduli space of smooth algebraic curves of genus g vanishes. The vanishing of the entire tautological ring for degree g-1 and higher, part of Faber's conjecture, is known in both homology and Chow --- it was proven by Looijenga, Ionel, and Graber-Vakil, and the class that we show vanishes is just one such tautological class. However, our approach, motivated by the Whitham perturbation theory of soliton equations, is completely new, elementary in the sense that no techniques beyond elementary complex analysis are used, and also leads to a natural non-speciality conjecture, which would imply many more vanishing results and relations among tautological classes. In the course of the proof we define and study foliations of the moduli space of curves constructed using periods of meromorphic differentials, in a way providing for meromorphic differentials a theory similar to that developed for abelian differen...

  2. How to Motivate Employees?

    Directory of Open Access Journals (Sweden)

    Andreja Kušar

    2014-02-01

    Full Text Available Research Question (RQ: How to motivate employees and keep them motivated? Purpose: The purpose of this study is to find out what motivates employees and what motivates employees for work. Method: The results of the questionnaire are graphically presented and described. Random sampling was utilized that included participants from various professional areas and demographic characteristics. The results showed a relationship between individual motivational factors related to education, age and type of employment. All of the questions were closed - type questions except for the last question, which was an open question, in which the respondents answered in their own words. Questions were analyzed using frequency analysis of individual responses. Pearson's Chi - squared test, Spearman's rank correlation and Fisher’s Exact test was made using R Commander. Results: The research findings showed which motivational factors motivate employees the most. These are especially non - material motivational factors, such as good relationships, jobs with challenges, advancement opportunities, clear instructions, good work conditions, company reputation, etc. Organization: The study will help managers understand their role in motivating employees as well as the types of motivational factors. Society: The research shows how individuals are motivated. Originality: Certain motivators in the study are ranked differently than was found in previous literature. Most probably the reason is that the respondents in this study favored intangible motivators (good relations with leadership and their colleagues, good working conditions, etc.. Limitations/Future Research: The limitation of this study was that the sample included employees of different ages, gender and years of service in various organizations. To enhance the study and to find similar results as in previous literature, more questions should have been asked as well as increasing the sample size.

  3. Hospital nurses' work motivation.

    Science.gov (United States)

    Toode, Kristi; Routasalo, Pirkko; Helminen, Mika; Suominen, Tarja

    2015-06-01

    The knowledge surrounding nurses' work motivation is currently insufficient, and previous studies have rarely taken into account the role of many influential background factors. This study investigates the motivation of Estonian nurses in hospitals, and how individual and organisational background factors influence their motivation to work. The study is quantitative and cross-sectional. An electronically self-reported questionnaire was used for data collection. The sample comprised of 201 Registered Nurses working in various hospital settings in Estonia. Data were analysed using descriptive statistics, two-sample Wilcoxon rank-sum (Mann-Whitney) test, Kruskal-Wallis equality-of-populations rank test and Spearman's correlation. Both extrinsic and intrinsic motivations were noted among hospital nurses. Nurses were moderately externally motivated (M = 3.63, SD = 0.89) and intrinsically strongly motivated (M = 4.98, SD = 1.03). A nurses' age and the duration of service were positively correlated with one particular area of extrinsic work motivation, namely introjected regulation (p extrinsic motivation (p = 0.016) and intrinsic work motivation (p = 0.004). The findings expand current knowledge of nurses' work motivation by describing the amount and orientation of work motivation among hospital nurses and highlighting background factors which should be taken into account in order to sustain and increase their intrinsic work motivation. The instrument used in the study can be an effective tool for nurse managers to determine a nurse's reasons to work and to choose a proper motivational strategy. Further research and testing of the instrument in different countries and in different contexts of nursing is however required. © 2014 Nordic College of Caring Science.

  4. Soil Water Retention Curve

    Science.gov (United States)

    Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

    2016-12-01

    Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

  5. [Psychological theories of motivation].

    Science.gov (United States)

    Quoniam, Nolwenn; Bungener, Catherine

    2004-03-01

    The comprehension of the principles guiding the human actions has always been an important aspect of philosophy. The development of experimental psychology first completely rejected all mental explanations such as will, intentions or motives. Behavior should then only be understood as determined by conditioning and learning. However, different theories denied that human behavior could be considered as purely reactive to the environment and stressed the active role of the organism on the environment. Theories from the humanist psychology and the social psychology described two kinds of motivation. The extrinsic motivation results from external stimuli and the intrinsic motivation from the organism himself. Our behavior is therefore determined by an interaction between our beliefs, expectations, needs and the environment. Actually, the concept of motivation is not well specified. It refers either to a global dynamic structure responsible for action either to a specific tendency toward some specific actions. Anyway, motivation is a concept infered from behavior. Therefore, its evaluation could only be secondary.

  6. Managing Joint Production Motivation

    DEFF Research Database (Denmark)

    Lindenberg, Siegwart; Foss, Nicolai Juul

    2011-01-01

    We contribute to the microfoundations of organizational performance by proffering the construct of joint production motivation. Under such motivational conditions individuals see themselves as part of a joint endeavor, each with his or her own roles and responsibilities; generate shared represent...... representations of actions and tasks; cognitively coordinate cooperation; and choose their own behaviors in terms of joint goals. Using goal-framing theory, we explain how motivation for joint production can be managed by cognitive/symbolic management and organizational design....

  7. Employee motivation and performance

    OpenAIRE

    Obiekwe, Nduka

    2010-01-01

    The subject matter of this research; employee motivation and performance seeks to look at how best employees can be motivated in order to achieve high performance within a company or organization. Managers and entrepreneurs must ensure that companies or organizations have a competent personnel that is capable to handle this task. This takes us to the problem question of this research “why is not a sufficient motivation for high performance?” This therefore establishes the fact that money is f...

  8. Employee Motivation and Performance

    OpenAIRE

    Obiekwe, Nduka

    2010-01-01

    The subject matter of this research; employee motivation and performance seeks to look at how best employees can be motivated in order to achieve high performance within a company or organization. Managers and entrepreneurs must ensure that companies or organizations have a competent personnel that is capable to handle this task. This takes us to the problem question of this research “why is not a sufficient motivation for high performance?” This therefore establishes the fact that money is f...

  9. Cubic B-spline curve approximation by curve unclamping

    OpenAIRE

    Chen, Xiao-Diao; Ma, Weiyin; Paul, Jean-Claude

    2010-01-01

    International audience; A new approach for cubic B-spline curve approximation is presented. The method produces an approximation cubic B-spline curve tangent to a given curve at a set of selected positions, called tangent points, in a piecewise manner starting from a seed segment. A heuristic method is provided to select the tangent points. The first segment of the approximation cubic B-spline curve can be obtained using an inner point interpolation method, least-squares method or geometric H...

  10. Motivating crowding theory - opening the black box of intrinsic motivation

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2010-01-01

    employees. Motivation crowding theory claims that this may be at the expense of intrinsic motivation, if the extrinsic motivation factor is perceived to be controlling. On the other hand, intrinsic motivation will be enhanced (crowded in), if the extrinsic motivation factor is perceived to be supportive......Public employees work for many other reasons than because they are paid for it. In other words, intrinsic motivation is an important determinant for their performance. Nonetheless, public sector organizations increasingly rely on extrinsic motivation factors such as monetary incentives to motivate....... Studies have found support for the motivation crowding claim, but have neglected intrinsic motivation. This study opens the black box of intrinsic motivation and finds a meaningful distinction between task motivation and public service motivation. Among 2,772 physiotherapists in the Danish public sector...

  11. Motivating crowding theory - opening the black box of intrinsic motivation

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2010-01-01

    Public employees work for many other reasons than because they are paid for it. In other words, intrinsic motivation is an important determinant for their performance. Nonetheless, public sector organizations increasingly rely on extrinsic motivation factors such as monetary incentives to motivate...... employees. Motivation crowding theory claims that this may be at the expense of intrinsic motivation, if the extrinsic motivation factor is perceived to be controlling. On the other hand, intrinsic motivation will be enhanced (crowded in), if the extrinsic motivation factor is perceived to be supportive....... Studies have found support for the motivation crowding claim, but have neglected intrinsic motivation. This study opens the black box of intrinsic motivation and finds a meaningful distinction between task motivation and public service motivation. Among 2,772 physiotherapists in the Danish public sector...

  12. Motivating salespeople: what really works.

    Science.gov (United States)

    Steenburgh, Thomas; Ahearne, Michael

    2012-01-01

    No sales force consists entirely of stars; sales staffs are usually made up mainly of solid perfomers, with smaller groups of laggards and rainmakers. Though most compensation plans approach these three groups as if they were the same, research shows that each is motivated by something different. By accounting for those differences in their incentive programs, companies can coax better performance from all their salespeople. As the largest cadre, core performers typically represent the greatest opportunity, but they're often ignored by incentive plans. Contests with prizes that vary in nature and value (and don't all go to stars) will inspire them to ramp up their efforts, and tiered targets will guide them up the performance curve. Laggards need quarterly bonuses to stay on track; when they have only annual bonuses, their revenues will drop 10%, studies show. This group is also motivated by social pressure-especially from new talent on the sales bench. Stars tend to get the most attention in comp plans, but companies often go astray by capping their commissions to control costs. If firms instead remove commission ceilings and pay extra for overachievement, they'll see the sales needle really jump. The key is to treat sales compensation not as an expense to rein in but as a portfolio of investments to manage. Companies that do this will be rewarded with much higher returns.

  13. Public Service Motivation and Monetary Incentives: Substitutes or Motivation Crowding?

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher

    2011-01-01

    motivation is the most important type of motivation in the delivery of public service, because it substitutes for egoistic motivation. Organizations whose members have high levels of PSM are therefore expected to be less dependent on utilitarian motivators such as monetary incentives. Motivation crowding...

  14. Reflection of curved shock waves

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.

  15. Reflection of curved shock waves

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.

  16. Heegner modules and elliptic curves

    CERN Document Server

    Brown, Martin L

    2004-01-01

    Heegner points on both modular curves and elliptic curves over global fields of any characteristic form the topic of this research monograph. The Heegner module of an elliptic curve is an original concept introduced in this text. The computation of the cohomology of the Heegner module is the main technical result and is applied to prove the Tate conjecture for a class of elliptic surfaces over finite fields; this conjecture is equivalent to the Birch and Swinnerton-Dyer conjecture for the corresponding elliptic curves over global fields.

  17. Closed planar curves without inflections

    CERN Document Server

    Ohno, Shuntaro; Umehara, Masaaki

    2011-01-01

    We define a computable topological invariant $\\mu(\\gamma)$ for generic closed planar regular curves $\\gamma$, which gives an effective lower bound for the number of inflection points on a given generic closed planar curve. Using it, we classify the topological types of locally convex curves (i.e. closed planar regular curves without inflections) whose numbers of crossings are less than or equal to five. Moreover, we discuss the relationship between the number of double tangents and the invariant $\\mu(\\gamma)$ on a given $\\gamma$.

  18. Motivated Reinforcement Learning

    CERN Document Server

    Maher, Mary Lou

    2009-01-01

    Motivated learning is a research field in artificial intelligence and cognitive modelling. This book describes how motivated reinforcement learning agents can be used in computer games for the design of non-player characters that can adapt their behaviour in response to unexpected changes in their environment

  19. Motivation in medical students

    NARCIS (Netherlands)

    Kusurkar, R.A.

    2012-01-01

    Introduction The importance of motivation in learning behaviour and education is well-researched and proven in general education, but much less in medical education. There is sometimes focus on increasing the quantity of motivation, but the how and why need more evidence. The aims of this thesis wer

  20. From motivation to acceptability

    DEFF Research Database (Denmark)

    Nordfalk, Francisca; Olejaz, Maria; Jensen, Anja M. B.

    2016-01-01

    Background: Over the past three decades, public attitudes to organ donation have been a subject of numerous studies focusing on donor motivation. Here, we present a fresh approach. We suggest focusing on public acceptability instead of motivation. The point is to understand public attitudes well...

  1. Mange unge mangler motivation

    DEFF Research Database (Denmark)

    Hutters, Camilla; Katznelson, Noemi

    2012-01-01

    Motivation er altafgørende for unges uddannelseschancer. Nyt forskningsprojekt skal gøre os klogere på, hvad der fremmer unges lyst til læring.......Motivation er altafgørende for unges uddannelseschancer. Nyt forskningsprojekt skal gøre os klogere på, hvad der fremmer unges lyst til læring....

  2. Motivation techniques for supervision

    Science.gov (United States)

    Gray, N. D.

    1974-01-01

    Guide has been published which deals with various aspects of employee motivation. Training methods are designed to improve communication between supervisors and subordinates, to create feeling of achievement and recognition for every employee, and to retain personnel confidence in spite of some negative motivators. End result of training is reduction or prevention of errors.

  3. What is this Motivation?

    Science.gov (United States)

    Waters, T. R.

    1971-01-01

    Maslow's Hierarchial Theory, Mcgregor's X & Y Theory, and Hertsberg's Hygiene Theory all based on motivation, are examined as to their effectiveness to increase worker production. The author feels management should not concentrate on motivation and offers his own theory, Spiral Web Theory, to help increase employee productiveness. (RB)

  4. Motivation in language learning

    Institute of Scientific and Technical Information of China (English)

    王骊

    2008-01-01

    Motivation is one of the key affective factors in language learning, which has been highly regarded and widely researched by both linguists and language teachers. It is very necessary for language teachers and learners to be aware of the influence of the motivation.

  5. Student Motivational Dynamics

    Science.gov (United States)

    McCaslin, Mary; Burross, Heidi Legg

    2008-01-01

    Background/Context: Student motivation typically has been studied as it relates to extrinsic (e.g., reinforcement) or intrinsic (e.g., personal choice) sources of influence, with scant attention to sociocultural context. This article builds on a previous article in this special issue that (1) addresses the role of opportunity in the motivation of…

  6. Children's Theories of Motivation

    Science.gov (United States)

    Gurland, Suzanne T.; Glowacky, Victoria C.

    2011-01-01

    To investigate children's theories of motivation, we asked 166 children (8-12 years of age) to rate the effect of various motivational strategies on task interest, over the short and long terms, in activities described as appealing or unappealing. Children viewed the rewards strategy as resulting in greatest interest except when implemented over…

  7. Motivation in medical students

    NARCIS (Netherlands)

    Kusurkar, R.A.

    2012-01-01

    Introduction The importance of motivation in learning behaviour and education is well-researched and proven in general education, but much less in medical education. There is sometimes focus on increasing the quantity of motivation, but the how and why need more evidence. The aims of this thesis

  8. Driver Behavior and Motivation.

    Science.gov (United States)

    Thomas, Patricia

    School bus driver behavior and motivation are continuing concerns for leaders/administrators in the field of transportation. Motivation begins with selection of a potential new driver. Drivers must like children and be patient, loyal, and punctual. The applicant's background must be verified, in view of the national concern for child safety.…

  9. Children's Theories of Motivation

    Science.gov (United States)

    Gurland, Suzanne T.; Glowacky, Victoria C.

    2011-01-01

    To investigate children's theories of motivation, we asked 166 children (8-12 years of age) to rate the effect of various motivational strategies on task interest, over the short and long terms, in activities described as appealing or unappealing. Children viewed the rewards strategy as resulting in greatest interest except when implemented over…

  10. Mange unge mangler motivation

    DEFF Research Database (Denmark)

    Hutters, Camilla; Katznelson, Noemi

    2012-01-01

    Motivation er altafgørende for unges uddannelseschancer. Nyt forskningsprojekt skal gøre os klogere på, hvad der fremmer unges lyst til læring.......Motivation er altafgørende for unges uddannelseschancer. Nyt forskningsprojekt skal gøre os klogere på, hvad der fremmer unges lyst til læring....

  11. Motives for SMS Use

    NARCIS (Netherlands)

    Peters, O.; Almekinders, Johan; van Buren, Ruud; Snippers, Roy; Wessels, Jacqueline

    This study was designed to identify, from a uses-and-gratifications point of view, the motives that young people in the age of 12 to 25 have for using SMS. The study also aimed to assess whether these SMS motives are related to age, gender, current education, mobile phone experience, SMS experience

  12. Measuring Adolescent Science Motivation

    Science.gov (United States)

    Schumm, Maximiliane F.; Bogner, Franz X.

    2016-01-01

    To monitor science motivation, 232 tenth graders of the college preparatory level ("Gymnasium") completed the Science Motivation Questionnaire II (SMQ-II). Additionally, personality data were collected using a 10-item version of the Big Five Inventory. A subsequent exploratory factor analysis based on the eigenvalue-greater-than-one…

  13. Motivation and Language Teaching.

    Science.gov (United States)

    Spithill, Alma C.

    1980-01-01

    Discusses the importance of student motivation in the foreign language classroom. Suggests that although most foreign language teachers are well trained in methods and materials, the psychological principles related to motivation and reinforcement are more elusive than those related to learning activities. (NCR)

  14. Enkele perspektiewe op Motivering

    Directory of Open Access Journals (Sweden)

    A. J. Van Wyk

    1984-11-01

    Full Text Available Different motivational theories in the literature seem to claim unique explanations of motivational behaviour. When these theories are evaluated against basic concepts and the process of motivation, it becomes clear that theory building in motivational terms really focuses on the same basic phenomenon. The implications and practical applications of the more job related contemporary theories of motivation are discussed. OpsommingDie indruk wat verskillende motiveringsteorieë in die literatuur skep, is dat elke teorie 'n unieke verklaring gee van gemotiveerde gedrag. Indien die basisbegrippe en die motiveringsproses egter as ankers gebruik word om teorieë te ontleed is dit moontlik om aan te toon dat teoriebou in die motiveringsliteratuur, niks anders is as beligtingsaspekte van dieselfde fenomeen nie. Die beligtingskant van kontemporêre teorieë is weliswaar meer werksverwant en die implikasies en toepassing daarvan word aangetoon.

  15. Motivational Goal Bracketing

    DEFF Research Database (Denmark)

    Nafziger, Julia; Koch, Alexander

    It is a puzzle why people often evaluate consequences of choices separately (narrow bracketing) rather than jointly (broad bracketing). We study the hypothesis that a present-biased individual, who faces two tasks, may bracket his goals narrowly for motivational reasons. Goals motivate because th...... of the tasks. Narrow goals have a stronger motivational force and thus can be optimal. In particular, if one task outcome becomes known before working on the second task, narrow bracketing is always optimal.......It is a puzzle why people often evaluate consequences of choices separately (narrow bracketing) rather than jointly (broad bracketing). We study the hypothesis that a present-biased individual, who faces two tasks, may bracket his goals narrowly for motivational reasons. Goals motivate because...

  16. Periods and Nori motives

    CERN Document Server

    Huber, Annette

    2017-01-01

    This book casts the theory of periods of algebraic varieties in the natural setting of Madhav Nori’s abelian category of mixed motives. It develops Nori’s approach to mixed motives from scratch, thereby filling an important gap in the literature, and then explains the connection of mixed motives to periods, including a detailed account of the theory of period numbers in the sense of Kontsevich-Zagier and their structural properties. Period numbers are central to number theory and algebraic geometry, and also play an important role in other fields such as mathematical physics. There are long-standing conjectures about their transcendence properties, best understood in the language of cohomology of algebraic varieties or, more generally, motives. Readers of this book will discover that Nori’s unconditional construction of an abelian category of motives (over fields embeddable into the complex numbers) is particularly well suited for this purpose. Notably, Kontsevich's formal period algebra represents a to...

  17. Surgeon compensation and motivation.

    Science.gov (United States)

    Leitch, K K; Walker, P M

    2000-06-01

    Financial incentives are the only form of compensation that will motivate surgeons at an academic health sciences center to perform the tasks outlined in the hospital's mission statement. A questionnaire divided into 5 sections: demographics, compensation, time allocation, benefits and incentives, and motivational factors. The Department of Surgery, The Toronto Hospital, Toronto, Ontario. All academic surgeons (N=64) practicing at The Toronto Hospital in July 1997. Of the 64 eligible mailed surveys, there were responses for 59. Of these 59 surgeons, 48 (81%) receive compensation through a fee-for-service method. However, only 32 (54%) of the surgeons prefer the fee-for-service method, while 18 (31%) prefer salary and 9 (15%) prefer an alternative system. On average, these academic surgeons spend 44% of their time teaching or performing research, for which they receive 14% of their total income. Of the motivational factors assessed, financial bonuses are a positive motivational factor for all "surgeon tasks." In addition, task-specific motivational factors were established for research, teaching, and operating, including research facilities, mentorship and prestige, and interesting case types, respectively. Surgeons are not appropriately renumerated for time spent on academic activities, and many would prefer an alternative form of compensation to the fee-for-service method. Knowledge that surgeons are receptive to tasks supporting the hospital's mission statement leads us to conclude that appropriate motivation can shape the activity of academic surgeons. Financial rewards ranked the highest as a motivational factor for all surgeon tasks; however, task-specific motivational factors were identified. Overall, multiple factors, specifically targeted to the individual, will serve to motivate. Thus, compensation packages based on individual preferences and personal motivational factors will be the most successful.

  18. Migration and the Wage Curve:

    DEFF Research Database (Denmark)

    Brücker, Herbert; Jahn, Elke J.

      Based on a wage curve approach we examine the labor market effects of migration in Germany. The wage curve relies on the assumption that wages respond to a change in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously...

  19. NURBS curve blending using extension

    Institute of Scientific and Technical Information of China (English)

    Yong-jin LIU; Rong-qi QIU; Xiao-hui LIANG

    2009-01-01

    Curve and surface blending is an important operation in CAD systems, in which a non-uniform rational B-spline (NURBS) has been used as the de facto standard. In local comer blending, two curves intersecting at that comer are first made disjoint, and then the third blending curve is added-in to smoothly join the two curves with G1-or G2-continuity. In this paper we present a study to solve the joint problem based on curve extension. The following nice properties of this extension algorithm are exploited in depth: (1) The parameterization of the original shapes does not change; (2) No additional fragments are created.Various examples are presented to demonstrate that our solution is simple and efficient.

  20. Simulating motivated cognition

    Science.gov (United States)

    Gevarter, William B.

    1991-01-01

    A research effort to develop a sophisticated computer model of human behavior is described. A computer framework of motivated cognition was developed. Motivated cognition focuses on the motivations or affects that provide the context and drive in human cognition and decision making. A conceptual architecture of the human decision-making approach from the perspective of information processing in the human brain is developed in diagrammatic form. A preliminary version of such a diagram is presented. This architecture is then used as a vehicle for successfully constructing a computer program simulation Dweck and Leggett's findings that relate how an individual's implicit theories orient them toward particular goals, with resultant cognitions, affects, and behavior.

  1. Lessons in Student Motivation

    Directory of Open Access Journals (Sweden)

    Errol Craig Sull

    2007-01-01

    Full Text Available The tools students have at their ready to do well are really amazing: engaging, thorough, and colorful textbooks; the Internet, of course; faculty who know how to teach and offer a plethora of information; and seemingly endless possibilities for optimal learning environments. Yet with all these improved “mousetraps” there is one factor that, if missing, will keep each of these silent – and the student will learn little or naught: motivation. Indeed, if the student is not motivated to learn, and his or her motivation is not kept up throughout a course, there is little the student will take away from the course.

  2. Delegation and Motivation

    DEFF Research Database (Denmark)

    Borowiecki, Karol Jan; Angst, Lukas

    2014-01-01

    In this article we study the determinants of decision rights transfer and its effects on the motivation of an agent. The study is based on a laboratory experiment conducted on 130 subjects playing an innovative principal-agent game. Interestingly, the results show that agents do not favour...... a delegation and a decision is considered rather burdensome. Although the experiment could not give support for the behavioural hypothesis of higher effort provided by participants who receive choice subsequently, the survey illuminates the interaction between delegation motives, effort motivators, goals...

  3. Motivation, cognition and pseudoscience.

    Science.gov (United States)

    Lindeman, M

    1998-12-01

    The article proposes a framework that views pseudoscientific beliefs as a joint function of the basic social motives and the default way of processing everyday information. The interplay between the basic motives and experiential thinking is illustrated with three examples. The first concerns comprehension of self via astrology and graphology, and the second involves the comprehension of unexpected events (one domain of the motive to comprehend the world). The last example describes health control by alternative medicine, as a modern way of controlling future outcomes.

  4. Object-Image Correspondence for Algebraic Curves under Projections

    Directory of Open Access Journals (Sweden)

    Joseph M. Burdis

    2013-03-01

    Full Text Available We present a novel algorithm for deciding whether a given planar curve is an image of a given spatial curve, obtained by a central or a parallel projection with unknown parameters. The motivation comes from the problem of establishing a correspondence between an object and an image, taken by a camera with unknown position and parameters. A straightforward approach to this problem consists of setting up a system of conditions on the projection parameters and then checking whether or not this system has a solution. The computational advantage of the algorithm presented here, in comparison to algorithms based on the straightforward approach, lies in a significant reduction of a number of real parameters that need to be eliminated in order to establish existence or non-existence of a projection that maps a given spatial curve to a given planar curve. Our algorithm is based on projection criteria that reduce the projection problem to a certain modification of the equivalence problem of planar curves under affine and projective transformations. To solve the latter problem we make an algebraic adaptation of signature construction that has been used to solve the equivalence problems for smooth curves. We introduce a notion of a classifying set of rational differential invariants and produce explicit formulas for such invariants for the actions of the projective and the affine groups on the plane.

  5. Irregular conformal block, spectral curve and flow equations

    CERN Document Server

    Choi, Sang Kwan; Zhang, Hong

    2015-01-01

    Irregular conformal block is motivated by the Argyres-Douglas type of N=2 super conformal gauge theory. We investigate the classical/NS limit of the irregular conformal block using spectral curve on a Riemann surface with irregular punctures, which is equivalent to the loop equation of irregular matrix model. The spectral curve is reduced to the second order (Virasoro symmetry, $SU(2)$ for the gauge theory) and third order ($W_3$ symmetry, $SU(3)$) differential equations of a polynomial with finite degree. The Virasoro and W symmetry generate flow equations in the spectral curve and determine the irregular conformal block, hence the partition function of the Argyres-Douglas theory ala AGT conjecture.

  6. Management styles and motivation.

    Science.gov (United States)

    Shearer, Dana Ann

    2012-01-01

    According to a review of the current literature, common managerial styles are transformational, transactional, and laissez-faire. When managers expand their leadership skills to improve the staff's morale, they must use a combination of transformational leadership behaviors and transactional contingent rewards to maximize their effectiveness on employees. A motivation theory such as Herzberg and Maslow enhances employees' motivation, morale, and satisfaction. Being able to motivate, empower, and influence staff improves satisfaction and retention levels among the team. A manager's leadership style influences motivation, morale, and retention in staff. Leaders are influenced by their educational development and the organizational culture. Organizational culture has an impact on a manager's style, which is forwarded to their followers.

  7. Children's theories of motivation.

    Science.gov (United States)

    Gurland, Suzanne T; Glowacky, Victoria C

    2011-09-01

    To investigate children's theories of motivation, we asked 166 children (8-12 years of age) to rate the effect of various motivational strategies on task interest, over the short and long terms, in activities described as appealing or unappealing. Children viewed the rewards strategy as resulting in greatest interest except when implemented over the long term for appealing activities. Individual difference analyses revealed that some children held operant theories of motivation, in which rewards were central, and others held hybrid theories, in which rewards were key, but some allowance was made for interest to be self-sustaining in the absence of inducements. Children's theories predicted their academic self-regulation. Their theories are discussed relative to an expert theory of motivation. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Handling motivation the Kindergarten

    DEFF Research Database (Denmark)

    Lund, Ole

    2016-01-01

    In this paper I will investigate the construction of motivation in interactions between educators and pre-school children. Hitherto research on this subject has typically been preoccupied with the minds and motives of children at the expense of their sensuous and bodily presence. On the basis...... of field work observations in a Danish Kindergarten, and interpretations drawing on theorizations of embodiment I intend to show how children’s motivation to engage can be developed from the ways the educators apply themselves bodily in the educational environment, and act upon and manipulate the bodily...... presence of the children, rather than explaining the intellectual or instrumental reasons behind the activities. Furthermore I will argue that the prerequisites for motivation is developed when educators hold on to activities; that is making the children repeat activities and over time making them capable...

  9. Measuring adolescent science motivation

    Science.gov (United States)

    Schumm, Maximiliane F.; Bogner, Franz X.

    2016-02-01

    To monitor science motivation, 232 tenth graders of the college preparatory level ('Gymnasium') completed the Science Motivation Questionnaire II (SMQ-II). Additionally, personality data were collected using a 10-item version of the Big Five Inventory. A subsequent exploratory factor analysis based on the eigenvalue-greater-than-one criterion, extracted a loading pattern, which in principle, followed the SMQ-II frame. Two items were dropped due to inappropriate loadings. The remaining SMQ-II seems to provide a consistent scale matching the findings in literature. Nevertheless, also possible shortcomings of the scale are discussed. Data showed a higher perceived self-determination in girls which seems compensated by their lower self-efficacy beliefs leading to equality of females and males in overall science motivation scores. Additionally, the Big Five personality traits and science motivation components show little relationship.

  10. Motivation and library management

    Directory of Open Access Journals (Sweden)

    Tatjana Likar

    2000-01-01

    Full Text Available The present article deals with motivation, its relation to management and its role and use in librarianship in our country and abroad. The countries where librarianship is well developed started to deal with library management and questions of motivation of library workers decades ago, whereas elsewhere the subject is at its start. The prerequisite for modern policy making is attention to the elements of modern library management. Librarians, library managers and directors of libraries should create a work environment providing long term satisfaction with work by means of certain knowledge and tools. The level of motivation of the staff is influenced by the so called higher factors deriving from the work process itself and related to work contents: achieve¬ment, recognition, trust and work itself. Extrinsic factors (income, interpersonal relations, technology of administration, company policy, working conditions, work con¬trol, personal security, job security and position... should exercise lesser impact on the level of motivation.

  11. Motivation and Adult Education.

    Science.gov (United States)

    Taylor, J. Rodney

    1982-01-01

    The author reviews theories of human motivation: Lewin's force field analysis, Skinner's operant reinforcement theory, and Maslow's hierarchy of needs. He then extracts the implications of these theories for adult learning. SK)

  12. From appraisal to motivation

    Directory of Open Access Journals (Sweden)

    Rudkovsky V. N.

    2009-06-01

    Full Text Available Some aspects related to identifying the level of the necessary personnel competence and motivation on introdusing the quality managament system in research and production enterprises are quoted.

  13. Motivation and Adult Education.

    Science.gov (United States)

    Taylor, J. Rodney

    1982-01-01

    The author reviews theories of human motivation: Lewin's force field analysis, Skinner's operant reinforcement theory, and Maslow's hierarchy of needs. He then extracts the implications of these theories for adult learning. SK)

  14. Lessons in Student Motivation

    OpenAIRE

    2007-01-01

    The tools students have at their ready to do well are really amazing: engaging, thorough, and colorful textbooks; the Internet, of course; faculty who know how to teach and offer a plethora of information; and seemingly endless possibilities for optimal learning environments. Yet with all these improved “mousetraps” there is one factor that, if missing, will keep each of these silent – and the student will learn little or naught: motivation. Indeed, if the student is not motivated to learn, a...

  15. Adaptive Motivation Theory

    Science.gov (United States)

    1985-06-01

    in behavior left to explain. Kleinginna and Kleinginna (1981) have gathered no fewer than 140 definitions of motivation that have appeared in the...34 ( Kleinginna 4 - . .o. . Z. and Kleinginna , 1981). As a result, if you are inclined to accept Maslow’s notions, you are less interested in the choice aspect of...Snyderman, B. (1959). The motivation to work. New York: Wiley. Jaques, E. (1961). Equitable payment. New York: Wiley, 1961. 45 Kleinginna , P. R. and

  16. Equations of hyperelliptic Shimura curves

    CERN Document Server

    Molina, Santiago

    2010-01-01

    We describe an algorithm that computes explicit models of hyperelliptic Shimura curves attached to an indefnite quaternion algebra over Q and Atkin-Lehner quotients of them. It exploits Cerednik-Drinfeld's non-archimedean uniformisation of Shimura curves, a formula of Gross and Zagier for the endomorphism ring of Heegner points over Artinian rings and the connection between Ribet's bimodules and the specialization of Heegner points. As an application, we provide a list of equations of Shimura curves and quotients of them obtained by our algorithm that had been conjectured by Kurihara.

  17. Poiseuille flow in curved spaces

    CERN Document Server

    Debus, J -D; Succi, S; Herrmann, H J

    2015-01-01

    We investigate Poiseuille channel flow through intrinsically curved (campylotic) media, equipped with localized metric perturbations (campylons). To this end, we study the flux of a fluid driven through the curved channel in dependence of the spatial deformation, characterized by the campylon parameters (amplitude, range and density). We find that the flux depends only on a specific combination of campylon parameters, which we identify as the average campylon strength, and derive a universal flux law for the Poiseuille flow. For the purpose of this study, we have improved and validated our recently developed lattice Boltzmann model in curved space by considerably reducing discrete lattice effects.

  18. Description of dose response curve

    OpenAIRE

    Al-Samarai, Firas

    2011-01-01

    The book included several methods to estimate LD50, in addition to explain how to use several programs to estimate LD50. Moreover the book illustrate the description of the dose response curves. Firas Al-Samarai

  19. Normal origamis of Mumford curves

    CERN Document Server

    Kremer, Karsten

    2010-01-01

    An origami (also known as square-tiled surface) is a Riemann surface covering a torus with at most one branch point. Lifting two generators of the fundamental group of the punctured torus decomposes the surface into finitely many unit squares. By varying the complex structure of the torus one obtains easily accessible examples of Teichm\\"uller curves in the moduli space of Riemann surfaces. The p-adic analogues of Riemann surfaces are Mumford curves. A p-adic origami is defined as a covering of Mumford curves with at most one branch point, where the bottom curve has genus one. A classification of all normal non-trivial p-adic origamis is presented and used to calculate some invariants. These can be used to describe p-adic origamis in terms of glueing squares.

  20. String networks as tropical curves

    CERN Document Server

    Ray, Koushik

    2008-01-01

    A prescription for obtaining supergravity solutions for planar (p,q)-string networks is presented, based on earlier results. It shows that networks may be looked upon as tropical curves emerging as the spine of the amoeba of a holomorphic curve in M-theory. The Kaehler potential of supergravity is identified with the corresponding Ronkin function. Implications of this identification in counting dyons is discussed.

  1. Growth curves for Laron syndrome.

    OpenAIRE

    Laron, Z; Lilos, P; Klinger, B.

    1993-01-01

    Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls co...

  2. Flow over riblet curved surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, J B R; Freire, A P Silva, E-mail: atila@mecanica.ufrj.br [Mechanical Engineering Program, Federal University of Rio de Janeiro (COPPE/UFRJ), C.P. 68503, 21.941-972, Rio de Janeiro, RJ (Brazil)

    2011-12-22

    The present work studies the mechanics of turbulent drag reduction over curved surfaces by riblets. The effects of surface modification on flow separation over steep and smooth curved surfaces are investigated. Four types of two-dimensional surfaces are studied based on the morphometric parameters that describe the body of a blue whale. Local measurements of mean velocity and turbulence profiles are obtained through laser Doppler anemometry (LDA) and particle image velocimetry (PIV).

  3. Linear Systems on Tropical Curves

    CERN Document Server

    Haase, Christian; Yu, Josephine

    2009-01-01

    A tropical curve \\Gamma is a metric graph with possibly unbounded edges, and tropical rational functions are continuous piecewise linear functions with integer slopes. We define the complete linear system |D| of a divisor D on a tropical curve \\Gamma analogously to the classical counterpart. We investigate the structure of |D| as a cell complex and show that linear systems are quotients of tropical modules, finitely generated by vertices of the cell complex. Using a finite set of generators, |D| defines a map from \\Gamma to a tropical projective space, and the image can be extended to a tropical curve of degree equal to \\deg(D). The tropical convex hull of the image realizes the linear system |D| as a polyhedral complex. We show that curves for which the canonical divisor is not very ample are hyperelliptic. We also show that the Picard group of a \\Q-tropical curve is a direct limit of critical groups of finite graphs converging to the curve.

  4. Interactional Motivation in Artificial Systems: Between Extrinsic and Intrinsic Motivation

    OpenAIRE

    Georgeon, Olivier; Marshall, James; Gay, Simon

    2012-01-01

    International audience; This paper introduces Interactional Motivation (IM) as a way to implement self-motivation in artificial systems. An interactionally motivated agent selects behaviors for the sake of enacting the behavior itself rather than for the value of the behavior’s outcome. IM contrasts with extrinsic motivation by the fact that it defines the agent’s motivation independently from the environment’s state. Because IM does not refer to the environment’s states, we argue that IM is ...

  5. Measuring motivation in schizophrenia: is a general state of motivation necessary for task-specific motivation?

    Science.gov (United States)

    Choi, Jimmy; Choi, Kee-Hong; Felice Reddy, L; Fiszdon, Joanna M

    2014-03-01

    Despite the important role of motivation in rehabilitation and functional outcomes in schizophrenia, to date, there has been little emphasis on how motivation is assessed. This is important, since different measures may tap potentially discrete motivational constructs, which in turn may have very different associations to important outcomes. In the current study, we used baseline data from 71 schizophrenia spectrum outpatients enrolled in a rehabilitation program to examine the relationship between task-specific motivation, as measured by the Intrinsic Motivation Inventory (IMI), and a more general state of volition/initiation, as measured by the three item Quality of Life (QLS) motivation index. We also examined the relationship of these motivation measures to demographic, clinical and functional variables relevant to rehabilitation outcomes. The two motivation measures were not correlated, and participants with low general state motivation exhibited a full range of task-specific motivation. Only the QLS motivation index correlated with variables relevant to rehabilitation outcomes. The lack of associations between QLS motivation index and IMI subscales suggests that constructs tapped by these measures may be divergent in schizophrenia, and specifically that task-specific intrinsic motivation is not contingent on a general state of motivation. That is, even in individuals with a general low motivational state (i.e. amotivation), interventions aimed at increasing task-specific motivation may still be effective. Moreover, the pattern of interrelationships between the QLS motivation index and variables relevant to psychosocial rehabilitation supports its use in treatment outcome studies.

  6. Measuring motivation in schizophrenia: Is a general state of motivation necessary for task-specific motivation?

    Science.gov (United States)

    Choi, Jimmy; Choi, Kee-Hong; Reddy, Felice; Fiszdon, Joanna M.

    2014-01-01

    Despite the important role of motivation in rehabilitation and functional outcomes in schizophrenia, to date, there has been little emphasis on how motivation is assessed. This is important, since different measures may tap potentially discrete motivational constructs, which in turn may have very different associations to important outcomes. In the current study, we used baseline data from 71 schizophrenia spectrum outpatients enrolled in a rehabilitation program to examine the relationship between task-specific motivation, as measured by the Intrinsic Motivation Inventory (IMI), and a more general state of volition/initiation, as measured by the three item Quality of Life (QLS) motivation index. We also examined the relationship of these motivation measures to demographic, clinical and functional variables relevant to rehabilitation outcomes. The two motivation measures were not correlated, and participants with low general state motivation exhibited a full range of task-specific motivation. Only the QLS motivation index correlated with variables relevant to rehabilitation outcomes. The lack of associations between QLS motivation index and IMI subscales suggests that constructs tapped by these measures may be divergent in schizophrenia, and specifically that task-specific intrinsic motivation is not contingent on a general state of motivation. That is, even in individuals with a general low motivational state (i.e. amotivation), interventions aimed at increasing task-specific motivation may still be effective. Moreover, the pattern of interrelationships between the QLS motivation index and variables relevant to psychosocial rehabilitation supports its use in treatment outcome studies. PMID:24529609

  7. FUTURE ENGINEER TRAINING: MOTIVATING TECHNIQUES

    OpenAIRE

    2016-01-01

    The motivating techniques for training future engineer are proposed. Intrinsic and extrinsic motivations in professional training have been analyzed. The peculiarities of the formation process of students’ motivation in learning language at non-language universities have been systematized. Heuristic training technology based on students’ motivation to cognitive research has been implemented.

  8. (Mis)managing employee motivation?

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher; Hvidtved, Johan; Andersen, Lotte Bøgh

    Motivated employees are crucial to all organizations, but some management initiatives may actually decrease motivation. Motivation crowding theory thus expects that command and incentives – if they are perceived as controlling - crowd out intrinsic motivation. The perception is thus expected...... to be vital, and this paper investigates how the perception of a specific command system – obligatory student plans – is associated with two types of employee motivation (public service motivation and intrinsic task motivation). Using a dataset with 3439 school teachers in Denmark, the analysis shows...... that the perception of obligatory student plans as controlling is negatively associated with different types of employee motivation, indicating that motivation crowding happens. Although the strength of the associations varies between the investigated types of motivation, the findings imply that practitioners should...

  9. (Mis)managing employee motivation?

    DEFF Research Database (Denmark)

    Jacobsen, Christian Bøtcher; Hvidtved, Johan; Andersen, Lotte Bøgh

    Motivated employees are crucial to all organizations, but some management initiatives may actually decrease motivation. Motivation crowding theory thus expects that command and incentives – if they are perceived as controlling - crowd out intrinsic motivation. The perception is thus expected...... to be vital, and this paper investigates how the perception of a specific command system – obligatory student plans – is associated with two types of employee motivation (public service motivation and intrinsic task motivation). Using a dataset with 3439 school teachers in Denmark, the analysis shows...... that the perception of obligatory student plans as controlling is negatively associated with different types of employee motivation, indicating that motivation crowding happens. Although the strength of the associations varies between the investigated types of motivation, the findings imply that practitioners should...

  10. Motivation and episodic memory performance

    OpenAIRE

    Ngaosuvan, Leonard

    2004-01-01

    In everyday life, motivation and learning are connected like music and dancing. Many educators realize this and work hard to improve their students' motivation. A motivated student may repeat and self-rehearse the content of a chapter more often, which leads to better learning. However, from a cognitive psychology point of view, it is still uncertain if motivation without differences in repetition or attention, affects episodic memory performance. That is, would a motivated student perform be...

  11. Employees' motivation and emloyees' benefits

    OpenAIRE

    Nedzelská, Eva

    2014-01-01

    The subject of this bachelor thesis is analysing methods how to stimulate and motivate employees. The theoretical part of the thesis deals with the concept of motivation, concepts close to motivation and selected existing theories of motivation. It also deals with employee benefits, function, division and benefits which are frequently offered to employees. The practical part of the thesis, mainly based on written and online questionnaires, concentrates on motivation of employees at Nedcon Boh...

  12. Curve Digitizer – A software for multiple curves digitizing

    Directory of Open Access Journals (Sweden)

    Florentin ŞPERLEA

    2010-06-01

    Full Text Available The Curve Digitizer is software that extracts data from an image file representing a graphicand returns them as pairs of numbers which can then be used for further analysis and applications.Numbers can be read on a computer screen stored in files or copied on paper. The final result is adata set that can be used with other tools such as MSEXCEL. Curve Digitizer provides a useful toolfor any researcher or engineer interested in quantifying the data displayed graphically. The image filecan be obtained by scanning a document

  13. Hunters' motivations and values:

    DEFF Research Database (Denmark)

    Radder, Laetitia; Bech-Larsen, Tino

    2008-01-01

    This article examines the values and motivations of South African biltong hunters. A hierarchical value map of associations between attributes, consequences and values resulted from laddering interviews with 34 hunters. The Means-End Chain approach proved useful in identifying: (a) personal values......, (b) wildlife value orientations, and (c) motivations associated with desired benefits and satisfactions. Values reflected socialization, achievement, stimulation, hedonism, universalism, and conformity. Materialism, attraction/interest, respect, environmentalism, and rational/scientific were...... the predominant wildlife value orientations. Motivations included male identity, escape, appreciation of nature, and bonding with family and friends. The study refuted perceptions that biltong hunters primarily hunt for the meat or for the sake of killing an animal....

  14. MOTIVATION IN ADAPTED SPORT

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Torralba

    2014-05-01

    Full Text Available This study examines the motivation for practice of sport of people with disabilities that form part to a federated sport.The sample was composed of 134 athletes of both genders and different disabilities.The “Participation Motivation Inventory Questionnaire” by Gill, Gross and Huddleston was used. The instrument was adapted to Paralympic sport and describes the main reasons that encourage the sports activity practice. The results haven´t found significant difference between men´s and women´s or between blind - visually impaired physical and motor disabilities. About the motivation of the practice of sport, worth highlighting the importance given to factors of fitness and health, like sport practice, improve the level, to compete, feel good and have fun, well above being popular, influenced by coaches or satisfy to parents.

  15. Automated Motivic Analysis

    DEFF Research Database (Denmark)

    Lartillot, Olivier

    2016-01-01

    of the successive notes and intervals, various sets of musical parameters may be invoked. In this chapter, a method is presented that allows for these heterogeneous patterns to be discovered. Motivic repetition with local ornamentation is detected by reconstructing, on top of “surface-level” monodic voices, longer...... for lossless compression. The structural complexity resulting from successive repetitions of patterns can be controlled through a simple modelling of cycles. Generally, motivic patterns cannot always be defined solely as sequences of descriptions in a fixed set of dimensions: throughout the descriptions......-term relations between non-adjacent notes related to deeper structures, and by tracking motives on the resulting syntagmatic network. These principles are integrated into a computational framework, the MiningSuite, developed in Matlab....

  16. Hunters' motivations and values:

    DEFF Research Database (Denmark)

    Radder, Laetitia; Bech-Larsen, Tino

    2008-01-01

    This article examines the values and motivations of South African biltong hunters. A hierarchical value map of associations between attributes, consequences and values resulted from laddering interviews with 34 hunters. The Means-End Chain approach proved useful in identifying: (a) personal values......, (b) wildlife value orientations, and (c) motivations associated with desired benefits and satisfactions. Values reflected socialization, achievement, stimulation, hedonism, universalism, and conformity. Materialism, attraction/interest, respect, environmentalism, and rational/scientific were...... the predominant wildlife value orientations. Motivations included male identity, escape, appreciation of nature, and bonding with family and friends. The study refuted perceptions that biltong hunters primarily hunt for the meat or for the sake of killing an animal....

  17. Physical Disability and Motivation

    Science.gov (United States)

    Prosen, Harry

    1965-01-01

    Motivating the physically handicapped individual to assist in his own rehabilitation is a complex problem. Difficulties in motivation are often based on disturbances in body image, which in turn are related both to the premorbid personality and the handicap. Treatment must be directed at the body image as well as the physical disability. Emotional disturbance following body injury should be expected and its absence is abnormal. Adequate rehabilitation entails a consideration of the effect of the rehabilitation process on the disabled person. The patient's basic abilities must be used to improve motivation. Rehabilitation procedures must focus on practical ways of coping with everyday life. Physical disability can mobilize underlying inferiority feelings and increase the need for dependency. Judicious use must be made of success and frustration in the rehabilitation program. PMID:14296008

  18. Psychometric curve and behavioral strategies for whisker-based texture discrimination in rats.

    Directory of Open Access Journals (Sweden)

    Takeshi Morita

    Full Text Available The rodent whisker system is a major model for understanding neural mechanisms for tactile sensation of surface texture (roughness. Rats discriminate surface texture using the whiskers, and several theories exist for how texture information is physically sensed by the long, moveable macrovibrissae and encoded in spiking of neurons in somatosensory cortex. However, evaluating these theories requires a psychometric curve for texture discrimination, which is lacking. Here we trained rats to discriminate rough vs. fine sandpapers and grooved vs. smooth surfaces. Rats intermixed trials at macrovibrissa contact distance (nose >2 mm from surface with trials at shorter distance (nose <2 mm from surface. Macrovibrissae were required for distant contact trials, while microvibrissae and non-whisker tactile cues were used for short distance trials. A psychometric curve was measured for macrovibrissa-based sandpaper texture discrimination. Rats discriminated rough P150 from smoother P180, P280, and P400 sandpaper (100, 82, 52, and 35 µm mean grit size, respectively. Use of olfactory, visual, and auditory cues was ruled out. This is the highest reported resolution for rodent texture discrimination, and constrains models of neural coding of texture information.

  19. Topological recursion and mirror curves

    CERN Document Server

    Bouchard, Vincent

    2012-01-01

    We study the constant contributions to the free energies obtained through the topological recursion applied to the complex curves mirror to toric Calabi-Yau threefolds. We show that the recursion reproduces precisely the corresponding Gromov-Witten invariants, which can be encoded in powers of the MacMahon function. As a result, we extend the scope of the "remodeling conjecture" to the full free energies, including the constant contributions. In the process we study how the pair of pants decomposition of the mirror curves plays an important role in the topological recursion. We also show that the free energies are not, strictly speaking, symplectic invariants, and that the recursive construction of the free energies does not commute with certain limits of mirror curves.

  20. Laffer Curves and Home Production

    Directory of Open Access Journals (Sweden)

    Kotamäki Mauri

    2017-06-01

    Full Text Available In the earlier related literature, consumption tax rate Laffer curve is found to be strictly increasing (see Trabandt and Uhlig (2011. In this paper, a general equilibrium macro model is augmented by introducing a substitute for private consumption in the form of home production. The introduction of home production brings about an additional margin of adjustment – an increase in consumption tax rate not only decreases labor supply and reduces the consumption tax base but also allows a substitution of market goods with home-produced goods. The main objective of this paper is to show that, after the introduction of home production, the consumption tax Laffer curve exhibits an inverse U-shape. Also the income tax Laffer curves are significantly altered. The result shown in this paper casts doubt on some of the earlier results in the literature.

  1. Rational points on elliptic curves

    CERN Document Server

    Silverman, Joseph H

    2015-01-01

    The theory of elliptic curves involves a pleasing blend of algebra, geometry, analysis, and number theory. This book stresses this interplay as it develops the basic theory, thereby providing an opportunity for advanced undergraduates to appreciate the unity of modern mathematics. At the same time, every effort has been made to use only methods and results commonly included in the undergraduate curriculum. This accessibility, the informal writing style, and a wealth of exercises make Rational Points on Elliptic Curves an ideal introduction for students at all levels who are interested in learning about Diophantine equations and arithmetic geometry. Most concretely, an elliptic curve is the set of zeroes of a cubic polynomial in two variables. If the polynomial has rational coefficients, then one can ask for a description of those zeroes whose coordinates are either integers or rational numbers. It is this number theoretic question that is the main subject of this book. Topics covered include the geometry and ...

  2. Canonical curves with low apolarity

    CERN Document Server

    Ballico, Edoardo; Notari, Roberto

    2010-01-01

    Let $k$ be an algebraically closed field and let $C$ be a non--hyperelliptic smooth projective curve of genus $g$ defined over $k$. Since the canonical model of $C$ is arithmetically Gorenstein, Macaulay's theory of inverse systems allows to associate to $C$ a cubic form $f$ in the divided power $k$--algebra $R$ in $g-2$ variables. The apolarity of $C$ is the minimal number $t$ of linear form in $R$ needed to write $f$ as sum of their divided power cubes. It is easy to see that the apolarity of $C$ is at least $g-2$ and P. De Poi and F. Zucconi classified curves with apolarity $g-2$ when $k$ is the complex field. In this paper, we give a complete, characteristic free, classification of curves $C$ with apolarity $g-1$ (and $g-2$).

  3. Curved spacetimes in the lab

    CERN Document Server

    Szpak, Nikodem

    2014-01-01

    We present some new ideas on how to design analogue models of quantum fields living in curved spacetimes using ultra-cold atoms in optical lattices. We discuss various types of static and dynamical curved spacetimes achievable by simple manipulations of the optical setup. Examples presented here contain two-dimensional spaces of positive and negative curvature as well as homogeneous cosmological models and metric waves. Most of them are extendable to three spatial dimensions. We mention some interesting phenomena of quantum field theory in curved spacetimes which might be simulated in such optical lattices loaded with bosonic or fermionic ultra-cold atoms. We also argue that methods of differential geometry can be used, as an alternative mathematical approach, for dealing with realistic inhomogeneous optical lattices.

  4. The New Keynesian Phillips Curve

    DEFF Research Database (Denmark)

    Ólafsson, Tjörvi

    This paper provides a survey on the recent literature on the new Keynesian Phillips curve: the controversies surrounding its microfoundation and estimation, the approaches that have been tried to improve its empirical fit and the challenges it faces adapting to the open-economy framework. The new...... Keynesian Phillips curve has been severely criticized for poor empirical dynamics. Suggested improvements involve making some adjustments to the standard sticky price framework, e.g. introducing backwardness and real rigidities, or abandoning the sticky price model and relying on models of inattentiveness......, learning or state-dependant pricing. The introduction of openeconomy factors into the new Keynesian Phillips curve complicate matters further as it must capture the nexus between price setting, inflation and the exchange rate. This is nevertheless a crucial feature for any model to be used for inflation...

  5. Algebraic curves of maximal cyclicity

    Science.gov (United States)

    Caubergh, Magdalena; Dumortier, Freddy

    2006-01-01

    The paper deals with analytic families of planar vector fields, studying methods to detect the cyclicity of a non-isolated closed orbit, i.e. the maximum number of limit cycles that can locally bifurcate from it. It is known that this multi-parameter problem can be reduced to a single-parameter one, in the sense that there exist analytic curves in parameter space along which the maximal cyclicity can be attained. In that case one speaks about a maximal cyclicity curve (mcc) in case only the number is considered and of a maximal multiplicity curve (mmc) in case the multiplicity is also taken into account. In view of obtaining efficient algorithms for detecting the cyclicity, we investigate whether such mcc or mmc can be algebraic or even linear depending on certain general properties of the families or of their associated Bautin ideal. In any case by well chosen examples we show that prudence is appropriate.

  6. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  7. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  8. Caloric Curves and Nuclear Expansion

    CERN Document Server

    Natowitz, J B; Ma, Y; Murray, M; Qin, L; Shlomo, S; Wada, R; Wang, J

    2002-01-01

    Nuclear caloric curves have been analyzed using an expanding Fermi gas hypothesis to extract average nuclear densities. In this approach the observed flattening of the caloric curves reflects progressively increasing expansion with increasing excitation energy. This expansion results in a corresponding decrease in the density and Fermi energy of the excited system. For nuclei of medium to heavy mass apparent densities $~0.3\\rho_0$ are reached at the higher excitation energies. The average densities derived in this manner are in good agreement with those derived using other, more complicated, techniques.

  9. Curved branes with regular support

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios [Sorbonne Universites, LPTHE, UMR CNRS 7589, Paris (France); University of Bern, Albert Einstein Center for Fundamental Physics, ITP, Bern (Switzerland); Cotsakis, Spiros; Klaoudatou, Ifigeneia [American University of the Middle East, Department of Mathematics, P. O. Box 220, Dasman (Kuwait)

    2016-09-15

    We study spacetime singularities in a general five-dimensional braneworld with curved branes satisfying four-dimensional maximal symmetry. The bulk is supported by an analog of perfect fluid with the time replaced by the extra coordinate. We show that contrary to the existence of finite-distance singularities from the brane location in any solution with flat (Minkowski) branes, in the case of curved branes there are singularity-free solutions for a range of equations of state compatible with the null energy condition. (orig.)

  10. Motivation and reward systems

    NARCIS (Netherlands)

    van Eerde, W.; Vodosek, M.; den Hartog, D.N.; McNett, J.M.

    2014-01-01

    Reward systems are identified as one of the human resource management (HRM) practices that may impact motivation. Reward systems may consist of several components, including financial and nonfinancial rewards, in fixed and variable amounts. Reinforcement, expectancy, and equity principles are discus

  11. Motivation og handlingskapacitet

    DEFF Research Database (Denmark)

    Andersen, Lotte Bøgh; Kristensen, Nicolai; Pedersen, Lene Holm

    2012-01-01

    Der har i flere år være en interesse for at undersøge motivationen hos producenterne af offentlige ydelser, mens der i mindre grad findes empiriske analyser af brugernes handlingskapacitet. Artiklen råder bod på dette ved at analysere forskelle i motivation og handlingskapacitet på fire serviceom......Der har i flere år være en interesse for at undersøge motivationen hos producenterne af offentlige ydelser, mens der i mindre grad findes empiriske analyser af brugernes handlingskapacitet. Artiklen råder bod på dette ved at analysere forskelle i motivation og handlingskapacitet på fire...... serviceområder (skoler, dagpasning, hospitaler og videregående uddannelser). Der anvendes henholdsvis et veletableret mål for public service motivation (n=377 producenter) og et nyudviklet mål for handlingskapacitet (n=1056 brugere). Resultaterne viser, at der er relativt højest handlingskapacitet og public...... service motivation på daginstitutionsområdet efterfulgt af skoleområdet, mens de videregående uddannelser placerer sig relativt lavest på begge variable. Hospitalsbrugerne har næsten lige så lav handlingskapacitet som brugerne af de videregående uddannelser, mens de hospitalsansattes public service...

  12. Motivation through Routine Documentation

    Science.gov (United States)

    Koth, Laurie J.

    2016-01-01

    This informed commentary article offers a simple, effective classroom management strategy in which the teacher uses routine documentation to motivate students both to perform academically and to behave in a manner consistent with established classroom rules and procedures. The pragmatic strategy is grounded in literature, free to implement,…

  13. Assessment of Teacher Motivation

    Science.gov (United States)

    Gokce, Feyyat

    2010-01-01

    The aim of this study is to contribute to the achievement of educational goals by determining teachers' levels of motivation. With this aim in mind, the opinions of 386 teachers employed in primary schools in Tokat province were sought. According to the findings of the study, the teachers stated that their needs were not fulfilled according to…

  14. Assessing Environmental Stewardship Motivation

    Science.gov (United States)

    Bramston, Paul; Pretty, Grace; Zammit, Charlie

    2011-01-01

    Environmental stewardship networks flourish across Australia. Although the environment benefits, this article looks to identify what volunteers draw from their stewardship. The authors adapted 16 questions that purportedly tap environmental stewardship motivation and administered them to a convenience sample of 318 university students and then to…

  15. Gamification and Student Motivation

    Science.gov (United States)

    Buckley, Patrick; Doyle, Elaine

    2016-01-01

    The literature suggests that gamified learning interventions may increase student engagement and enhance learning. We empirically investigate this by exploring the impact of intrinsic and extrinsic motivation on the participation and performance of over 100 undergraduate students in an online gamified learning intervention. The paper makes a…

  16. Motivational Orientations in Work

    Science.gov (United States)

    Murtonen, Mari; Olkinuora, Erkki; Palonen, Tuire; Hakkarainen, Kai; Lehtinen, Erno

    2008-01-01

    The rapid development in working life during recent decades has changed the structures of work organisations and expectations of employees' work. Differing forms of professional employment and different types of organisational environments likely promote different types of motivational patterns in workers. The aim of this study was to apply a…

  17. Developing a Motivational Strategy.

    Science.gov (United States)

    Janson, Robert

    1979-01-01

    Describes the use of job enrichment techniques as tools for increased productivity and organizational change. The author's motivational work design model changes not only the job design but also structural elements such as physical layout, workflow, and organizational relationships. Behavior change is more important than job enrichment. (MF)

  18. Gamification and Student Motivation

    Science.gov (United States)

    Buckley, Patrick; Doyle, Elaine

    2016-01-01

    The literature suggests that gamified learning interventions may increase student engagement and enhance learning. We empirically investigate this by exploring the impact of intrinsic and extrinsic motivation on the participation and performance of over 100 undergraduate students in an online gamified learning intervention. The paper makes a…

  19. Predicting Intrinsic Motivation

    Science.gov (United States)

    Martens, Rob; Kirschner, Paul A.

    2004-01-01

    Intrinsic motivation can be predicted from participants' perceptions of the social environment and the task environment (Ryan & Deci, 2000)in terms of control, relatedness and competence. To determine the degree of independence of these factors 251 students in higher vocational education (physiotherapy and hotel management) indicated the extent to…

  20. Motivation for Change

    Science.gov (United States)

    ... No. (SMA) 13-4782ENG Printed 2013 Cha nge Motivation fo r John Taylor Lucy Mr. Williams Matthew John’s Mom John’s Dad Social Worker This publication contains graphic depictions of a traumatic event that may be unsuitable for children. 1 John was at a party drinking with ...

  1. Impulsive action and motivation

    NARCIS (Netherlands)

    Frijda, N.H.

    2010-01-01

    This paper explores the way in which emotions are causal determinants of action. It argues that emotional events, as appraised by the individual, elicit changes in motive states (called states of action readiness), which in turn may (or may not) cause action. Actions can be elicited automatically,

  2. Delegation and Motivation

    DEFF Research Database (Denmark)

    Borowiecki, Karol Jan; Angst, Lukas

    2014-01-01

    In this article we study the determinants of decision rights transfer and its effects on the motivation of an agent. The study is based on a laboratory experiment conducted on 130 subjects playing an innovative principal-agent game. Interestingly, the results show that agents do not favour a dele...

  3. Motivational Orientations in Work

    Science.gov (United States)

    Murtonen, Mari; Olkinuora, Erkki; Palonen, Tuire; Hakkarainen, Kai; Lehtinen, Erno

    2008-01-01

    The rapid development in working life during recent decades has changed the structures of work organisations and expectations of employees' work. Differing forms of professional employment and different types of organisational environments likely promote different types of motivational patterns in workers. The aim of this study was to apply a…

  4. Interpolation and Polynomial Curve Fitting

    Science.gov (United States)

    Yang, Yajun; Gordon, Sheldon P.

    2014-01-01

    Two points determine a line. Three noncollinear points determine a quadratic function. Four points that do not lie on a lower-degree polynomial curve determine a cubic function. In general, n + 1 points uniquely determine a polynomial of degree n, presuming that they do not fall onto a polynomial of lower degree. The process of finding such a…

  5. Principal Curves on Riemannian Manifolds.

    Science.gov (United States)

    Hauberg, Soren

    2016-09-01

    Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.

  6. Variability among polysulphone calibration curves

    Energy Technology Data Exchange (ETDEWEB)

    Casale, G R [University of Rome ' La Sapienza' , Physics Department, P.le A. Moro 2, I-00185, Rome (Italy); Borra, M [ISPESL - Istituto Superiore per la Prevenzione E la Sicurezza del Lavoro, Occupational Hygiene Department, Via Fontana Candida 1, I-0040 Monteporzio Catone (RM) (Italy); Colosimo, A [University of Rome ' La Sapienza' , Department of Human Physiology and Pharmacology, P.le A. Moro 2, I-00185, Rome (Italy); Colucci, M [ISPESL - Istituto Superiore per la Prevenzione E la Sicurezza del Lavoro, Occupational Hygiene Department, Via Fontana Candida 1, I-0040 Monteporzio Catone (RM) (Italy); Militello, A [ISPESL - Istituto Superiore per la Prevenzione E la Sicurezza del Lavoro, Occupational Hygiene Department, Via Fontana Candida 1, I-0040 Monteporzio Catone (RM) (Italy); Siani, A M [University of Rome ' La Sapienza' , Physics Department, P.le A. Moro 2, I-00185, Rome (Italy); Sisto, R [ISPESL - Istituto Superiore per la Prevenzione E la Sicurezza del Lavoro, Occupational Hygiene Department, Via Fontana Candida 1, I-0040 Monteporzio Catone (RM) (Italy)

    2006-09-07

    Within an epidemiological study regarding the correlation between skin pathologies and personal ultraviolet (UV) exposure due to solar radiation, 14 field campaigns using polysulphone (PS) dosemeters were carried out at three different Italian sites (urban, semi-rural and rural) in every season of the year. A polysulphone calibration curve for each field experiment was obtained by measuring the ambient UV dose under almost clear sky conditions and the corresponding change in the PS film absorbance, prior and post exposure. Ambient UV doses were measured by well-calibrated broad-band radiometers and by electronic dosemeters. The dose-response relation was represented by the typical best fit to a third-degree polynomial and it was parameterized by a coefficient multiplying a cubic polynomial function. It was observed that the fit curves differed from each other in the coefficient only. It was assessed that the multiplying coefficient was affected by the solar UV spectrum at the Earth's surface whilst the polynomial factor depended on the photoinduced reaction of the polysulphone film. The mismatch between the polysulphone spectral curve and the CIE erythemal action spectrum was responsible for the variability among polysulphone calibration curves. The variability of the coefficient was related to the total ozone amount and the solar zenith angle. A mathematical explanation of such a parameterization was also discussed.

  7. Space curves, anholonomy and nonlinearity

    Indian Academy of Sciences (India)

    Radha Balakrishnan

    2005-04-01

    Using classical differential geometry, we discuss the phenomenon of anholonomy that gets associated with a static and a moving curve. We obtain the expressions for the respective geometric phases in the two cases and interpret them. We show that there is a close connection between anholonomy and nonlinearity in a wide class of nonlinear systems.

  8. The New Keynesian Phillips Curve

    DEFF Research Database (Denmark)

    Ólafsson, Tjörvi

    , learning or state-dependant pricing. The introduction of openeconomy factors into the new Keynesian Phillips curve complicate matters further as it must capture the nexus between price setting, inflation and the exchange rate. This is nevertheless a crucial feature for any model to be used for inflation...... forecasting in a small open economy like Iceland....

  9. S-shaped learning curves

    NARCIS (Netherlands)

    Murre, J.M.J.

    2014-01-01

    In this article, learning curves for foreign vocabulary words are investigated, distinguishing between a subject-specific learning rate and a material-specific parameter that is related to the complexity of the items, such as the number of syllables. Two experiments are described, one with Turkish w

  10. The soil reference shrinkage curve

    CERN Document Server

    Chertkov, V Y

    2014-01-01

    A recently proposed model showed how a clay shrinkage curve is transformed to the soil shrinkage curve at the soil clay content higher than a critical one. The objective of the present work was to generalize this model to the soil clay content lower a critical one. I investigated (i) the reference shrinkage curve, that is, one without cracks; (ii) the superficial layer of aggregates, with changed pore structure compared with the intraaggregate matrix; and (iii) soils with sufficiently low clay content where there are large pores inside the intraaggregate clay (so-called lacunar pores). The methodology is based on detail accounting for different contributions to the soil volume and water content during shrinkage. The key point is the calculation of the lacunar pore volume variance at shrinkage. The reference shrinkage curve is determined by eight physical soil parameters: (1) oven-dried specific volume; (2) maximum swelling water content; (3) mean solid density; (4) soil clay content; (5) oven-dried structural...

  11. Language Learning Motivation: The Palestinian Context. Attitudes, Motivation, and Orientations

    OpenAIRE

    Musleh, Rana Yaser

    2011-01-01

    Given that motivation is held to be a major affective variable influencing SLA, the present study examines L2 motivation among Palestinian students from the age of 12 to 18 years old. Considering the present situation in Palestine, the motives that drive learners to study a foreign language will certainly be affected by the context (culture and values) in which the learning takes place. The present study involves the investigation of motivation towards learning English as a foreign language...

  12. Motivation and Ways to Motivate Students of Middle School

    Institute of Scientific and Technical Information of China (English)

    朱洪琼

    2012-01-01

    Motivation is critical in English learning of middle school,thus,how to effectively motivate students in English learning is an important problem.This study intends to find ways to motivate students of middle school.Self-report data were collected from 45 students in The Experiment Middle School Attached to Yunnan Normal University by using a close-ended questionnaire.

  13. Reading Motivation: 10 Elements for Success. Motivational Strategies That Work!

    Science.gov (United States)

    Gerbig, Kori M.

    2009-01-01

    Motivational processes are the foundation for coordinating cognitive goals and strategies in reading. Becoming an excellent, active reader involves attunement of motivational processes with cognitive and language processes in reading. This article presents K-12 strategies for motivating reading success. It describes 10 instructional elements that…

  14. Families of bitangent planes of space curves and minimal non-fibration families

    KAUST Repository

    Lubbes, Niels

    2014-01-01

    A cone curve is a reduced sextic space curve which lies on a quadric cone and does not pass through the vertex. We classify families of bitangent planes of cone curves. The methods we apply can be used for any space curve with ADE singularities, though in this paper we concentrate on cone curves. An embedded complex projective surface which is adjoint to a degree one weak Del Pezzo surface contains families of minimal degree rational curves, which cannot be defined by the fibers of a map. Such families are called minimal non-fibration families. Families of bitangent planes of cone curves correspond to minimal non-fibration families. The main motivation of this paper is to classify minimal non-fibration families. We present algorithms which compute all bitangent families of a given cone curve and their geometric genus. We consider cone curves to be equivalent if they have the same singularity configuration. For each equivalence class of cone curves we determine the possible number of bitangent families and the number of rational bitangent families. Finally we compute an example of a minimal non-fibration family on an embedded weak degree one Del Pezzo surface.

  15. Testing modified gravity at large distances with THINGS' rotation curves

    CERN Document Server

    Mastache, Jorge; de la Macorra, Axel

    2012-01-01

    Recently a new -quantum motivated- theory of gravity has been proposed that modifies the standard Newtonian potential at large distances when spherical symmetry is considered. Accordingly, Newtonian gravity is altered by adding an extra Rindler acceleration term that has to be -phenomenologically- determined. Here we consider a standard and a power-law generalization of the Rindler modified Newtonian potential. The new terms in the gravitational potential are hypothesized to play the role of dark matter in galaxies. Our galactic model includes the mass of the integrated gas, and stars for which we consider three stellar mass functions (Kroupa, diet-Salpeter, and free mass model). We test this idea by fitting rotation curves of seventeen Low Surface Brightness (LSB) galaxies from The HI Nearby Galaxy Survey (THINGS). We find that the Rindler parameters do not perform a suitable fit to the rotation curves in comparison to standard dark matter profiles (NFW and Burkert) and, in addition, the computed parameters ...

  16. Replicating the benefits of closed timelike curves without breaking causality

    CERN Document Server

    Yuan, Xiao; Thompson, Jayne; Haw, Jing Yan; Vedral, Vlatko; Ralph, Timothy C; Lam, Ping Koy; Weedbrook, Christian; Gu, Mile

    2014-01-01

    In general relativity, closed timelike curves can break causality with remarkable and unsettling consequences. At the classical level, they induce causal paradoxes disturbing enough to motivate conjectures that explicitly prevent their existence. At the quantum level, resolving such paradoxes induce radical benefits - from cloning unknown quantum states to solving problems intractable to quantum computers. Instinctively, one expects these benefits to vanish if causality is respected. Here we show that in harnessing entanglement, we can efficiently solve NP-complete problems and clone arbitrary quantum states - even when all time-travelling systems are completely isolated from the past. Thus, the many defining benefits of closed timelike curves can still be harnessed, even when causality is preserved. Our results unveil the subtle interplay between entanglement and general relativity, and significantly improve the potential of probing the radical effects that may exist at the interface between relativity and q...

  17. Motivational Interviewing and Adolescent Psychopharmacology

    Science.gov (United States)

    Dilallo, John J.; Weiss, Gony

    2009-01-01

    The use of motivational interviewing strategies in the practice of adolescent psychopharmacology is described. Motivational interviewing is an efficient and collaborative style of clinical interaction and this helps adolescent patients to integrate their psychiatric difficulties into a more resilient identity.

  18. Broken bracelets, Molien series, paraffin wax and an elliptic curve of conductor 48

    CERN Document Server

    Amdeberhan, Tewodros; Moll, Victor H

    2011-01-01

    This paper introduces the concept of necklace binomial coefficients motivated by the enumeration of a special type of sequences. Several properties of these coefficients are described, including a connection between their roots and an elliptic curve. Further links are given to a physical model from quantum mechanical supersymmetry as well as properties of alkane molecules in chemistry.

  19. Motivational aspects of sport volunteers

    OpenAIRE

    Mičinec, Adam

    2017-01-01

    Title: The motivational aspects of sport volunteerism. Objectives: The main aim of this bachelor work is to find out motivational aspects of sport volunteers, who have taken part in sport event. Methods: In this thesis was used quality method to get informations - specifically it was a structure interview with associated questions. Results: It was find out that it is appropriate to get those volunteers with inner motivation. These volunteers do not need to be so much motivated by external mot...

  20. Motivation and evaluation of empolyees

    OpenAIRE

    Sinkulová, Anna

    2015-01-01

    My bachelor thesis is focused on motivation and assessment of employees in the company. The aim of this thesis is to investigate the influence of team building and benefits on employees' motivation. Literature based theoretical part of my thesis describes and investigates the real meaning and purpose of motivation and basic motivational concepts. Furthermore, I outlined the basics behind employee benefits, team building and also stated the current given trends in these areas. The practical pa...

  1. Motivating Staff, Parents, and Children.

    Science.gov (United States)

    Jones, Cynthia Cavenaugh

    Two motivational theories considered particularly useful in administering early childhood programs are discussed, and guidelines for motivating staff, parents, and children are provided. First, the two-factor theory of motivation within organizations, as outlined by Herzberg (1959), is described. Offered in this section are a list of motivators…

  2. Influence of Motivation on Wayfinding

    Science.gov (United States)

    Srinivas, Samvith

    2010-01-01

    This research explores the role of affect in the domain of human wayfinding by asking if increased motivation will alter the performance across various routes of increasing complexity. Participants were asked to perform certain navigation tasks within an indoor Virtual Reality (VR) environment under either motivated and not-motivated instructions.…

  3. Clustering Teachers' Motivations for Teaching

    Science.gov (United States)

    Visser-Wijnveen, Gerda J.; Stes, Ann; Van Petegem, Peter

    2014-01-01

    The motivation to teach is a powerful, yet neglected, force in teaching at institutes of higher education. A better understanding of academics' motivations for teaching is necessary. The aim of this mixed-method study was to identify groups with distinctively different motivations for teaching. Six clusters were identified: expertise, duty,…

  4. Work Motivation: Theory and Practice.

    Science.gov (United States)

    Katzell, Raymond A.; Thompson, Donna E.

    1990-01-01

    Presents theories of motivation classified as those dealing either with exogenous causes or with endogenous processes. The following strategies for improving work motivation are discussed: (1) personal motives; (2) incentives and rewards; (3) reinforcement; (4) goal-setting techniques; (5) personal and material resources; (6) social and group…

  5. Motivating Staff, Parents, and Children.

    Science.gov (United States)

    Jones, Cynthia Cavenaugh

    Two motivational theories considered particularly useful in administering early childhood programs are discussed, and guidelines for motivating staff, parents, and children are provided. First, the two-factor theory of motivation within organizations, as outlined by Herzberg (1959), is described. Offered in this section are a list of motivators…

  6. Epistemic Motivation and Conceptual Change.

    Science.gov (United States)

    Boyle, Robert A.; And Others

    While the conceptual change model of learning has contributed much to our understanding of how children learn science, recent criticisms of the model point out its lack of attention to motivational issues. This paper examines one such motivational construct of importance to the model: epistemic motivation. After a description of the construct, we…

  7. Motivational Engineering for Pilot Training.

    Science.gov (United States)

    Herzberg, Frederick I.; And Others

    The study was an investigation of student pilot motivation for, and toward, the Air Training Command's undergraduate pilot training (UPT) program. The motivation hygiene approach was used to identify the motivational factors operating in the UPT program systematically. This approach has been used extensively in industry and with success in a…

  8. A catalog of special plane curves

    CERN Document Server

    Lawrence, J Dennis

    2014-01-01

    Among the largest, finest collections available-illustrated not only once for each curve, but also for various values of any parameters present. Covers general properties of curves and types of derived curves. Curves illustrated by a CalComp digital incremental plotter. 12 illustrations.

  9. Music and Combat Motivation

    Science.gov (United States)

    2015-04-01

    1   AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY MUSIC AND COMBAT MOTIVATION by Sally C. Maddocks, Major, USAF Master of...accordance with Air Force Instruction 51-303, it is not copyrighted, but is the property of the United States government.  3   Music has the power...are many historical examples from which to draw evidence of the impact of music on fielded forces. One must study not only the historical events, but

  10. Motivation for cyberterrorism

    CSIR Research Space (South Africa)

    Veerasamy, N

    2010-08-01

    Full Text Available for communication, recruitment and planning terrorist missions, but malicious targeting of this critical infrastructure could cause widespread damage. Already in 1998, Pollitt explained that cyberterrorism is the premeditated, politically motivated attack... to protest a certain issue or promote a cause. Furthermore, one of the most cited definitions of cyberterrorism as presented by Denning before the Special Oversight Panel on Terrorism [2], refers to cyberterrorism as unlawful attacks and threats...

  11. Moral Concepts and Motivation

    OpenAIRE

    Greenberg, Mark

    2009-01-01

    I first argue that standard versions of moral internalism are untenable in light of a type of example that has not previously been considered in metaethical discussions. As a consequence of having unusual views, a good-willed thinker could make moral judgments and recognize moral facts without having a disposition to be motivated to act accordingly (and without believing himself to have reasons for action). Moreover, on a familiar conception of irrationality as incoherence, the thinker in q...

  12. Principal Curves on Riemannian Manifolds

    DEFF Research Database (Denmark)

    Hauberg, Søren

    2015-01-01

    Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only...... in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimize a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend...... from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls...

  13. Invariance for Single Curved Manifold

    KAUST Repository

    Castro, Pedro Machado Manhaes de

    2012-08-01

    Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.

  14. Optical conductivity of curved graphene.

    Science.gov (United States)

    Chaves, A J; Frederico, T; Oliveira, O; de Paula, W; Santos, M C

    2014-05-07

    We compute the optical conductivity for an out-of-plane deformation in graphene using an approach based on solutions of the Dirac equation in curved space. Different examples of periodic deformations along one direction translates into an enhancement of the optical conductivity peaks in the region of the far- and mid-infrared frequencies for periodicities ∼100 nm. The width and position of the peaks can be changed by dialling the parameters of the deformation profiles. The enhancement of the optical conductivity is due to intraband transitions and the translational invariance breaking in the geometrically deformed background. Furthermore, we derive an analytical solution of the Dirac equation in a curved space for a general deformation along one spatial direction. For this class of geometries, it is shown that curvature induces an extra phase in the electron wave function, which can also be explored to produce interference devices of the Aharonov-Bohm type.

  15. Supersymmetric Spacetimes from Curved Superspace

    CERN Document Server

    Kuzenko, Sergei M

    2015-01-01

    We review the superspace technique to determine supersymmetric spacetimes in the framework of off-shell formulations for supergravity in diverse dimensions using the case of 3D N=2 supergravity theories as an illustrative example. This geometric formalism has several advantages over other approaches advocated in the last four years. Firstly, the infinitesimal isometry transformations of a given curved superspace form, by construction, a finite-dimensional Lie superalgebra, with its odd part corresponding to the rigid supersymmetry transformations. Secondly, the generalised Killing spinor equation, which must be obeyed by the supersymmetry parameters, is a consequence of the more fundamental superfield Killing equation. Thirdly, general rigid supersymmetric theories on a curved spacetime are readily constructed in superspace by making use of the known off-shell supergravity-matter couplings and restricting them to the background chosen. It is the superspace techniques which make it possible to generate arbitra...

  16. Curved canals: Ancestral files revisited

    Directory of Open Access Journals (Sweden)

    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

  17. A Study of Hyperelliptic Curves in Cryptography

    Directory of Open Access Journals (Sweden)

    Reza Alimoradi

    2016-08-01

    Full Text Available Elliptic curves are some specific type of curves known as hyper elliptic curves. Compared to the integer factorization problem(IFP based systems, using elliptic curve based cryptography will significantly decrease key size of the encryption. Therefore, application of this type of cryptography in systems that need high security and smaller key size has found great attention. Hyperelliptic curves help to make key length shorter. Many investigations are done with regard to improving computations, hardware and software implementation of these curves, their security and resistance against attacks. This paper studies and analyzes researches done about security and efficiency of hyperelliptic curves.

  18. Elastic Curves on the Sphere

    Science.gov (United States)

    1992-12-16

    12 = (K,, + )- (29) K 2 (see [3]). The parameter KM represents the amplitude of the periodic curva - ture function and sm denotes the value at which K...Additamentum De curvis elasticis. Methodus Inveniendi Lineas Curvas Maximi Minimive Proprietate Gaudentes, Ser. 1., Vol. 24, Lausanne 1744. 17 [10...Mathematical Theory of Elasticity. 4th. ed., Cambridge University Press, 1927. [12] G. Nielson. Bernstein/ Bezier Curves and Splines on Spheres based upon

  19. Accelerating Around an Unbanked Curve

    Science.gov (United States)

    Mungan, Carl E.

    2006-02-01

    The December 2004 issue of TPT presented a problem concerning how a car should accelerate around an unbanked curve of constant radius r starting from rest if it is to avoid skidding. Interestingly enough, two solutions were proffered by readers.2 The purpose of this note is to compare and contrast the two approaches. Further experimental investigation of various turning strategies using a remote-controlled car and overhead video analysis could make for an interesting student project.

  20. Macdonald formula for curves with planar singularities

    CERN Document Server

    Maulik, Davesh

    2011-01-01

    We generalize Macdonald's formula for the cohomology of Hilbert schemes of points on a curve from smooth curves to curves with planar singularities: we relate the cohomology of the Hilbert schemes to the cohomology of the compactified Jacobian of the curve. The new formula is a consequence of a stronger identity between certain perverse sheaves defined by a family of curves satisfying mild conditions, whose proof makes an essential use of Ng\\^o's support theorem for compactified Jacobians.

  1. Motivational interviewing and specialty pharmacy.

    Science.gov (United States)

    Berger, Bruce A; Bertram, Carl T

    2015-01-01

    It is well documented in substance abuse and health care literature that motivational interviewing is an evidenced-based and effective intervention for influencing patient behaviors and associated positive health outcomes. The introduction of motivational interviewing training in specialty pharmacy has great potential to increase patient and pharmacist satisfaction, maximize adherence rates, and improve health outcomes. This commentary examines the need for effective approaches for improving patient adherence and outcomes and briefly describes the history and efficacy of motivational interviewing. Case studies using traditional approaches to patient care and motivational interviewing are analysed, and real-world experience using motivational interviewing is presented in the form of a specialty pharmacy case study.

  2. Multiple motives and persuasive communication : Creative elaboration as a result of impression motivation and accuracy motivation

    NARCIS (Netherlands)

    Nienhuis, AE; Manstead, ASR; Spears, R

    2001-01-01

    The authors examined the influence of impression motivation (Experiments 1 and 2) and the combined effects of accuracy motivation and impression motivation (Experiment 3) on the elaboration of persuasive messages as reflected in attitude change and cognitive responses. Intermediate levels of impress

  3. A Preliminary Study of Classroom Motivators and De-Motivators from a Motivation-Hygiene Perspective

    Science.gov (United States)

    Katt, James A.; Condly, Steven J.

    2009-01-01

    This study seeks to begin answering two simple questions: "What motivates our students?" and its corollary, "What prevents our students from being motivated?" The motivation-hygiene theory (F. Herzberg, "Work and the nature of man," World Publishing, Cleveland, OH, 1966), a well-tested theory from organizational…

  4. A Preliminary Study of Classroom Motivators and De-Motivators from a Motivation-Hygiene Perspective

    Science.gov (United States)

    Katt, James A.; Condly, Steven J.

    2009-01-01

    This study seeks to begin answering two simple questions: "What motivates our students?" and its corollary, "What prevents our students from being motivated?" The motivation-hygiene theory (F. Herzberg, "Work and the nature of man," World Publishing, Cleveland, OH, 1966), a well-tested theory from organizational psychology, holds that people's…

  5. Multiple motives and persuasive communication : Creative elaboration as a result of impression motivation and accuracy motivation

    NARCIS (Netherlands)

    Nienhuis, AE; Manstead, ASR; Spears, R

    The authors examined the influence of impression motivation (Experiments 1 and 2) and the combined effects of accuracy motivation and impression motivation (Experiment 3) on the elaboration of persuasive messages as reflected in attitude change and cognitive responses. Intermediate levels of

  6. Motivational Interviewing and Rehabilitation Counseling Practice

    Science.gov (United States)

    Wagner, C. C.; McMahon, B. T.

    2004-01-01

    This article explores commonalities between rehabilitation counseling and the counseling approach known as motivational interviewing. Motivational interviewing is an empirically supported, clientcentered, directive counseling approach designed to promote client motivation and reduce motivational conflicts and barriers to change. The underpinnings…

  7. LINS Curve in Romanian Economy

    Directory of Open Access Journals (Sweden)

    Emilian Dobrescu

    2016-02-01

    Full Text Available The paper presents theoretical considerations and empirical evidence to test the validity of the Laffer in Narrower Sense (LINS curve as a parabola with a maximum. Attention is focused on the so-called legal-effective tax gap (letg. The econometric application is based on statistical data (1990-2013 for Romania as an emerging European economy. Three cointegrating regressions (fully modified least squares, canonical cointegrating regression and dynamic least squares and three algorithms, which are based on instrumental variables (two-stage least squares, generalized method of moments, and limited information maximum likelihood, are involved.

  8. Principal -bundles on Nodal Curves

    Indian Academy of Sciences (India)

    Usha N Bhosle

    2001-08-01

    Let be a connected semisimple affine algebraic group defined over . We study the relation between stable, semistable -bundles on a nodal curve and representations of the fundamental group of . This study is done by extending the notion of (generalized) parabolic vector bundles to principal -bundles on the desingularization of and using the correspondence between them and principal -bundles on . We give an isomorphism of the stack of generalized parabolic bundles on with a quotient stack associated to loop groups. We show that if is simple and simply connected then the Picard group of the stack of principal -bundles on is isomorphic to ⊕ , being the number of components of .

  9. Sound propagation over curved barriers

    Science.gov (United States)

    Pierce, Allan D.; Main, Geoffrey L.; Kearns, James A.; Hsieh, H.-A.

    1986-01-01

    Wide barriers with curved tops are studied with emphasis placed on circumstances whereby the local radius of curvature R of the barrier is continuous along the surface and is large compared to a wavelength. Results analogous to those given by Hayek et al. (1978) are reviewed and extended to cases where the radius of curvature and the surface impedance may vary with position. Circumstances not easily interpreted within the framework of the model proposed by Keller (1956) and Hayek et al. are also considered.

  10. Reconfigurable Double-Curved Mould

    DEFF Research Database (Denmark)

    Raun, Christian; Kirkegaard, Poul Henning

    2012-01-01

    . This happens fast, automatic and without production of waste, and the manipulated surface is fair and robust, eliminating the need for additional, manual treatment. Limitations to the possibilities of the flexible form are limited curvature and limited level of detail, making it especially suited for larger......, double curved surfaces like facades or walls, where the curvature of each element is relatively small in comparison to the overall shape. In the proposed dynamic mould system, where only a set of points is defined, a stiff membrane interpolates the surface between points. To function as a surface...

  11. Membranes Wrapped on Holomorphic Curves

    CERN Document Server

    Gauntlett, J P; Pakis, S; Waldram, D; Gauntlett, Jerome P.; Kim, Nakwoo; Pakis, Stathis; Waldram, Daniel

    2002-01-01

    We construct supergravity solutions dual to the twisted field theories arising when M-theory membranes wrap holomorphic curves in Calabi-Yau n-folds. The solutions are constructed in an Abelian truncation of maximal D=4 gauged supergravity and then uplifted to D=11. For four-folds and five-folds we find new smooth AdS/CFT examples and for all cases we analyse the nature of the singularities that arise. Our results provide an interpretation of certain charged topological AdS black holes. We also present the generalised calibration two-forms for the solutions.

  12. Motives for Barter

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    Barter is used not only in developing countries and not only by small companies. Even some of the largest U.S. companies are involved in barter. The most frequently bartered goods and services are media and travel. Researchers, who investigate barter, sometimes cite motives for barter but there has...... not been published (to the author’s knowledge) any framework that would allow classification of barter drivers. The paper examines whether the theory of consumption values framework could be used to classify barter drivers identified by a literature review. Various types of barter are considered (direct...

  13. Motives for Barter

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    Barter is used not only in developing countries and not only by small companies. Even some of the largest U.S. companies are involved in barter. The most frequently bartered goods and services are media and travel. Researchers, who investigate barter, sometimes cite motives for barter but there has...... not been published (to the author’s knowledge) any framework that would allow classification of barter drivers. The paper examines whether the theory of consumption values framework could be used to classify barter drivers identified by a literature review. Various types of barter are considered (direct...

  14. Motives for barter

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    2011-01-01

    Barter is not something that was present only before invention of money. Even Fortune 500 companies are involved in barter. The most common bartered goods and services are media and travel. As the amount of barter increases even in the U.S., it is worth investigating the reasons why organizations...... use barter. The paper provides a literature review of barter motives digested from academic journal articles covered in the Web of Science and EBSCO databases. The review includes also drivers that are specific for developing countries....

  15. Successful innovation by motivation

    Directory of Open Access Journals (Sweden)

    Petra Koudelková

    2015-10-01

    Full Text Available Innovation is one of the most important factors for business growth. Human capital plays a significant role in the successful process of innovation. This article deals with employee motivation in the innovation process and the main scientific aim of this study is to present results of research that was undertaken in the Czech Republic at the beginning of 2013. Questionnaires were used for the survey and statistical analyses such as Chi square test or Hierarchical cluster analysis were used for data processing. This study also provides a theoretical and practical overview of business innovation in the Czech Republic.

  16. Motives for barter

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    2011-01-01

    Barter is not something that was present only before invention of money. Even Fortune 500 companies are involved in barter. The most common bartered goods and services are media and travel. As the amount of barter increases even in the U.S., it is worth investigating the reasons why organizations...... use barter. The paper provides a literature review of barter motives digested from academic journal articles covered in the Web of Science and EBSCO databases. The review includes also drivers that are specific for developing countries....

  17. The motivation to express prejudice.

    Science.gov (United States)

    Forscher, Patrick S; Cox, William T L; Graetz, Nicholas; Devine, Patricia G

    2015-11-01

    Contemporary prejudice research focuses primarily on people who are motivated to respond without prejudice and the ways in which unintentional bias can cause these people to act in a manner inconsistent with this motivation. However, some real-world phenomena (e.g., hate speech, hate crimes) and experimental findings (e.g., Plant & Devine, 2001, 2009) suggest that some prejudice is intentional. These phenomena and findings are difficult to explain solely from the motivations to respond without prejudice. We argue that some people are motivated to express prejudice, and we develop the Motivation to Express Prejudice Scale (MP) to measure this motivation. In 7 studies involving more than 6,000 participants, we demonstrate that, across scale versions targeted at Black people and gay men, the MP has good reliability and convergent, discriminant, and predictive validity. In normative climates that prohibit prejudice, the internal and external motivations to express prejudice are functionally nonindependent, but they become more independent when normative climates permit more prejudice toward a target group. People high in the motivation to express prejudice are relatively likely to resist pressure to support programs promoting intergroup contact and to vote for political candidates who support oppressive policies. The motivation to express prejudice predicted these outcomes even when controlling for attitudes and the motivations to respond without prejudice. This work encourages contemporary prejudice researchers to give greater consideration to the intentional aspects of negative intergroup behavior and to broaden the range of phenomena, target groups, and samples that they study.

  18. The motivation to express prejudice

    Science.gov (United States)

    Forscher, Patrick S.; Cox, William T. L.; Graetz, Nicholas; Devine, Patricia G.

    2015-01-01

    Contemporary prejudice research focuses primarily on people who are motivated to respond without prejudice and the ways in which unintentional bias can cause these people to act inconsistent with this motivation. However, some real-world phenomena (e.g., hate speech, hate crimes) and experimental findings (e.g., Plant & Devine, 2001; 2009) suggest that some expressions of prejudice are intentional. These phenomena and findings are difficult to explain solely from the motivations to respond without prejudice. We argue that some people are motivated to express prejudice, and we develop the motivation to express prejudice (MP) scale to measure this motivation. In seven studies involving more than 6,000 participants, we demonstrate that, across scale versions targeted at Black people and gay men, the MP scale has good reliability and convergent, discriminant, and predictive validity. In normative climates that prohibit prejudice, the internal and external motivations to express prejudice are functionally non-independent, but they become more independent when normative climates permit more prejudice toward a target group. People high in the motivation to express prejudice are relatively likely to resist pressure to support programs promoting intergroup contact and vote for political candidates who support oppressive policies. The motivation to express prejudice predicted these outcomes even when controlling for attitudes and the motivations to respond without prejudice. This work encourages contemporary prejudice researchers to broaden the range of samples, target groups, and phenomena that they study, and more generally to consider the intentional aspects of negative intergroup behavior. PMID:26479365

  19. Differential geometry and topology of curves

    CERN Document Server

    Animov, Yu

    2001-01-01

    Differential geometry is an actively developing area of modern mathematics. This volume presents a classical approach to the general topics of the geometry of curves, including the theory of curves in n-dimensional Euclidean space. The author investigates problems for special classes of curves and gives the working method used to obtain the conditions for closed polygonal curves. The proof of the Bakel-Werner theorem in conditions of boundedness for curves with periodic curvature and torsion is also presented. This volume also highlights the contributions made by great geometers. past and present, to differential geometry and the topology of curves.

  20. Smarandache Curves in Minkowski Space-time

    OpenAIRE

    Turgut, Melih; Yilmaz, Suha

    2008-01-01

    A regular curve in Minkowski space-time, whose position vector is composed by Frenet frame vectors on another regular curve, is called a Smarandache Curve. In this paper, we define a special case of such curves and call it Smarandache TB2 Curves in the space E41. Moreover, we compute formulas of its Frenet apparatus according to base curve via the method expressed in [3]. By this way, we obtain an another orthonormal frame of E41.

  1. Motivations and marketing manager age

    Directory of Open Access Journals (Sweden)

    Gutić Dragutin

    2008-01-01

    Full Text Available Motivation research up to now perceive managers as a homogeneous group and do not include numerous individual differences. Age differences between people are an important factor which influences their motivation altogether. Motifs are not static but dynamic categories and structures which, among other things, also depend on a person's experience during person's development. This work's objective is first of all to define whether a real marketing manager's motivation profile in Croatia today corresponds to their expected or supposed profile? In this work secondary and primary data resources are used. Field examination of marketing manager's motives and motivation was conducted by a structured questionnaire on an intended occasional sample of 60 examinees (N=60 from the whole Croatia, the very same being marketing managers (marketing service managers, sales managers (sales service managers and tourist community directors. We divided the group of 60 examinees into three homogeneous age groups: :'A' (n = 20, aged to 35; 'B' (n = 20, aged between 35 and 50; 'C' (n = 20, aged over 50. Examinees' registered motives were classified into four groups: direct material motives (Ms; job safety and job (work promotion motives (Mt; professional improving and profession promotion motives: gaining new knowledge, abilities and skills (Mc; work climate and atmosphere, and other similar motives (Mp. Authors entered this research with belief that younger managers will be mostly motivated for professional improving and gaining new knowledge and skills; we expect middle aged managers to be mostly motivated for safety and job promotion, and managers in an advanced age should probably be mostly motivated for direct income and earnings.

  2. Motivation in action: A process model of L2 motivation

    OpenAIRE

    1998-01-01

    As part of a long-term project aimed at designing classroom interventions to motivate language learners, we have searched for a motivation model that could serve as a theoretical basis for the methodological applications. We have found that none of the existing models we considered were entirely adequate for our purpose for three reasons: (1) they did not provide a sufficiently comprehensive and detailed summary of all the relevant motivational influences on classroom behaviour; (2) they tend...

  3. Measuring Motivations of Crowdworkers: The Multidimensional Crowdworker Motivation Scale

    OpenAIRE

    Posch, Lisa; Bleier, Arnim; Strohmaier, Markus

    2017-01-01

    Crowd employment is a new form of short term and flexible employment which has emerged during the past decade. For understanding this new form of employment, it is crucial to understand the underlying motivations of the workforce involved in it. This paper presents the Multidimensional Crowdworker Motivation Scale (MCMS), a scale for measuring the motivation of crowdworkers on micro-task platforms. The scale is theoretically grounded in Self-Determination Theory and tailored specifically to t...

  4. Distinguishing subtypes of extrinsic motivation among people with mild to borderline intellectual disability : Distinguishing subtypes of extrinsic motivation

    NARCIS (Netherlands)

    Frielink, N.; Schuengel, C.; Embregts, P.J.C.M.

    Background According to self-determination theory, motivation is ordered in types, including amotivation, extrinsic motivation and intrinsic motivation. Self-determination theory defines four subtypes of extrinsic motivation: external motivation, introjected motivation, identified motivation and

  5. Applications of Space-Filling-Curves to Cartesian Methods for CFD

    Science.gov (United States)

    Aftosmis, M. J.; Murman, S. M.; Berger, M. J.

    2003-01-01

    This paper presents a variety of novel uses of space-filling-curves (SFCs) for Cartesian mesh methods in CFD. While these techniques will be demonstrated using non-body-fitted Cartesian meshes, many are applicable on general body-fitted meshes-both structured and unstructured. We demonstrate the use of single theta(N log N) SFC-based reordering to produce single-pass (theta(N)) algorithms for mesh partitioning, multigrid coarsening, and inter-mesh interpolation. The intermesh interpolation operator has many practical applications including warm starts on modified geometry, or as an inter-grid transfer operator on remeshed regions in moving-body simulations Exploiting the compact construction of these operators, we further show that these algorithms are highly amenable to parallelization. Examples using the SFC-based mesh partitioner show nearly linear speedup to 640 CPUs even when using multigrid as a smoother. Partition statistics are presented showing that the SFC partitions are, on-average, within 15% of ideal even with only around 50,000 cells in each sub-domain. The inter-mesh interpolation operator also has linear asymptotic complexity and can be used to map a solution with N unknowns to another mesh with M unknowns with theta(M + N) operations. This capability is demonstrated both on moving-body simulations and in mapping solutions to perturbed meshes for control surface deflection or finite-difference-based gradient design methods.

  6. Directed Motivational Currents: Using vision to create effective motivational pathways

    Directory of Open Access Journals (Sweden)

    Christine Muir

    2013-10-01

    Full Text Available Vision, that is, the mental representation of the sensory experience of a future goal state (involving imagination and imagery, is currently at the forefront of motivational innovation, and in recent years it has been seen increasingly more often in the motivational tool kit of practicing language teachers. Theories such as Dörnyei’s L2 motivational self system have explored the power that creating effective visions can harness (see, e.g., Dörnyei & Kubanyiova, 2014 and when viewed in conjunction with other current research avenues, such as future time perspective and dynamic systems theory, vision offers exciting potential. A Directed Motivational Current is a new motivational construct that we suggest is capable of integrating many current theoretical strands with vision: It can be described as a motivational drive which energises long-term, sustained behaviour (such as language learning, and through placing vision and goals as critical central components within this construct, it offers real and practical motivational potential. In this conceptual paper, we first discuss current understandings of vision and of Directed Motivational Currents, and then analyse how they may be optimally integrated and employed to create effective motivational pathways in language learning environments.

  7. Evaluating arguments during instigations of defence motivation and accuracy motivation.

    Science.gov (United States)

    Liu, Cheng-Hong

    2017-05-01

    When people evaluate the strength of an argument, their motivations are likely to influence the evaluation. However, few studies have specifically investigated the influences of motivational factors on argument evaluation. This study examined the effects of defence and accuracy motivations on argument evaluation. According to the compatibility between the advocated positions of arguments and participants' prior beliefs and the objective strength of arguments, participants evaluated four types of arguments: compatible-strong, compatible-weak, incompatible-strong, and incompatible-weak arguments. Experiment 1 revealed that participants possessing a high defence motivation rated compatible-weak arguments as stronger and incompatible-strong ones as weaker than participants possessing a low defence motivation. However, the strength ratings between the high and low defence groups regarding both compatible-strong and incompatible-weak arguments were similar. Experiment 2 revealed that when participants possessed a high accuracy motivation, they rated compatible-weak arguments as weaker and incompatible-strong ones as stronger than when they possessed a low accuracy motivation. However, participants' ratings on both compatible-strong and incompatible-weak arguments were similar when comparing high and low accuracy conditions. The results suggest that defence and accuracy motivations are two major motives influencing argument evaluation. However, they primarily influence the evaluation results for compatible-weak and incompatible-strong arguments, but not for compatible-strong and incompatible-weak arguments. © 2016 The British Psychological Society.

  8. Flow characteristics of curved ducts

    Directory of Open Access Journals (Sweden)

    Rudolf P.

    2007-10-01

    Full Text Available Curved channels are very often present in real hydraulic systems, e.g. curved diffusers of hydraulic turbines, S-shaped bulb turbines, fittings, etc. Curvature brings change of velocity profile, generation of vortices and production of hydraulic losses. Flow simulation using CFD techniques were performed to understand these phenomena. Cases ranging from single elbow to coupled elbows in shapes of U, S and spatial right angle position with circular cross-section were modeled for Re = 60000. Spatial development of the flow was studied and consequently it was deduced that minor losses are connected with the transformation of pressure energy into kinetic energy and vice versa. This transformation is a dissipative process and is reflected in the amount of the energy irreversibly lost. Least loss coefficient is connected with flow in U-shape elbows, biggest one with flow in Sshape elbows. Finally, the extent of the flow domain influenced by presence of curvature was examined. This isimportant for proper placement of mano- and flowmeters during experimental tests. Simulations were verified with experimental results presented in literature.

  9. Capacity theory on algebraic curves

    CERN Document Server

    Rumely, Robert S

    1989-01-01

    Capacity is a measure of size for sets, with diverse applications in potential theory, probability and number theory. This book lays foundations for a theory of capacity for adelic sets on algebraic curves. Its main result is an arithmetic one, a generalization of a theorem of Fekete and Szegö which gives a sharp existence/finiteness criterion for algebraic points whose conjugates lie near a specified set on a curve. The book brings out a deep connection between the classical Green's functions of analysis and Néron's local height pairings; it also points to an interpretation of capacity as a kind of intersection index in the framework of Arakelov Theory. It is a research monograph and will primarily be of interest to number theorists and algebraic geometers; because of applications of the theory, it may also be of interest to logicians. The theory presented generalizes one due to David Cantor for the projective line. As with most adelic theories, it has a local and a global part. Let /K be a smooth, complet...

  10. Miniature curved artificial compound eyes.

    Science.gov (United States)

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

    2013-06-04

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories.

  11. Curve Length Estimation using Vertix Chain Code Curve Length Estimation

    Directory of Open Access Journals (Sweden)

    Habibollah Haron

    2010-09-01

    Full Text Available Most of the applications in image analysis are based on Freeman chain code. In this paper, for the first time, vertex chain code (VCC proposed by Bribiesca is applied to improve length estimation of the 2D digitized curve. The chain code has some preferences such as stable in shifting, turning, mirroring movement of image and has normalized starting point. Due to the variety of length estimator methods, we focused on the three specific techniques. First, the way Bribiesca proposed which is based on counting links between vertices; second, based on maximum length digital straight segments (DSSs and lastly local metrics. The results of these length estimators with the real perimeter are compared. Results thus obtained exhibits thatlength estimation using VCC is nearest to the actual length.

  12. YOUNG ATHLETES' MOTIVATIONAL PROFILES

    Directory of Open Access Journals (Sweden)

    Juan Antonio Moreno Murcia

    2007-06-01

    Full Text Available The aim of this study was to examine the relationship between motivational characteristics and dispositional flow. In order to accomplish this goal, motivational profiles emerging from key constructs within Achievement Goal Theory and Self-Determination Theory were related to the dispositional flow measures. A sample of 413 young athletes (Age range 12 to 16 years completed the PMCSQ-2, POSQ, SMS and DFS measures. Cluster analysis results revealed three profiles: a "self-determined profile" characterised by higher scores on the task-involving climate perception and on the task orientation; a "non-self-determined profile", characterised by higher scores on ego-involving climate perception and ego orientation; and a "low self-determined and low non-self-determined profile" which had the lowest dispositional flow. No meaningful differences were found between the "self-determined profile" and the "non-self-determined profile" in dispositional flow. The "self-determined profile" was more commonly associated with females, athletes practising individual sports and those training more than three days a week. The "non-self-determined profile" was more customary of males and athletes practising team sports as well as those training just two or three days a week

  13. Motivational beliefs, values, and goals.

    Science.gov (United States)

    Eccles, Jacquelynne S; Wigfield, Allan

    2002-01-01

    This chapter reviews the recent research on motivation, beliefs, values, and goals, focusing on developmental and educational psychology. The authors divide the chapter into four major sections: theories focused on expectancies for success (self-efficacy theory and control theory), theories focused on task value (theories focused on intrinsic motivation, self-determination, flow, interest, and goals), theories that integrate expectancies and values (attribution theory, the expectancy-value models of Eccles et al., Feather, and Heckhausen, and self-worth theory), and theories integrating motivation and cognition (social cognitive theories of self-regulation and motivation, the work by Winne & Marx, Borkowski et al., Pintrich et al., and theories of motivation and volition). The authors end the chapter with a discussion of how to integrate theories of self-regulation and expectancy-value models of motivation and suggest new directions for future research.

  14. Transition curves for highway geometric design

    CERN Document Server

    Kobryń, Andrzej

    2017-01-01

    This book provides concise descriptions of the various solutions of transition curves, which can be used in geometric design of roads and highways. It presents mathematical methods and curvature functions for defining transition curves. .

  15. Atlas of stress-strain curves

    CERN Document Server

    2002-01-01

    The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...

  16. Curved Gabor Filters for Fingerprint Image Enhancement

    CERN Document Server

    Gottschlich, Carsten

    2011-01-01

    Gabor filters play an important role in many application areas for the enhancement of various types of images and the extraction of Gabor features. For the purpose of enhancing curved structures in noisy images, we introduce curved Gabor filters which locally adapt their shape to the direction of flow. These curved Gabor filters enable the choice of filter parameters which increase the smoothing power without creating artifacts in the enhanced image. In this paper, curved Gabor filters are applied to the curved ridge and valley structure of low-quality fingerprint images. First, we combine two orientation field estimation methods in order to obtain a more robust estimation for very noisy images. Next, curved regions are constructed by following the respective local orientation and they are used for estimating the local ridge frequency. Lastly, curved Gabor filters are defined based on curved regions and they are applied for the enhancement of low-quality fingerprint images. Experimental results on the FVC2004...

  17. Motivation of Professional Creative Thinking

    OpenAIRE

    Mergalуаs M. Kashapov; Anna V. Leybina

    2009-01-01

    The aim of this study was to reveal correlation between motivation and creative professional thinking. Four hundred and seventy-one Russians of diff erent trades participated in the study. It was supposed that motivational structure and level of creative professional thinking were interrelated. The connection between motivational components and professional thinking was revealed. Tendencies of transition form situational level of thinking to oversituational one were determined. It was found o...

  18. Environmental Participation and Environmental Motivation

    OpenAIRE

    Torgler, Benno; María A. García Valiñas; Macintyre, Alison

    2009-01-01

    We explore whether environmental motivation affects environmental behavior by focusing on volunteering. The paper first introduces a theoretical model of volunteering in environmental organizations. In a next step, it tests the hypothesis working with a large micro data set covering 32 countries from both Western and Eastern Europe using several different proxies to measure environmental motivation. Our results indicate that environmental motivation has a strong impact on individuals? volunta...

  19. Simple techniques can increase motivation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E.A.

    1982-12-01

    Productivity depends upon strong motivation. This article describes how the symptoms of weak motivation can be detected among engineers and other employees and what to do about it. Fortunately, most people want to be productive and respond to simple motivation building techniques. These techniques include establishing twoway communication between supervisor and subordinate, delegating authority on the basis of responsibility, effective organization of time, and the use of positive reinforcement (or rewards) and, when conditions merit it, negative reinforcement (or sanctions).

  20. Biopsychosocial correlates of work motivation

    OpenAIRE

    Liesienė, Justina; Endriulaitienė, Auksė

    2008-01-01

    Background, purpose. Work motivation is a potential predictor of employee turnover, job satisfaction, commitment, job performance and psychological wellbeing. Researchers argue that motivated employees work more effectively. The purpose of the current study was to identify biological (gender, age and health), psychological (personality traits) and social (marital status, children, work sector and position) factors related to employees’ work motivation. It was also predicted that subjectively ...

  1. Interval timing, dopamine, and motivation

    OpenAIRE

    Balcı, Fuat

    2014-01-01

    The dopamine clock hypothesis suggests that the dopamine level determines the speed of the hypothetical internal clock. However, dopaminergic function has also been implicated for motivation and thus the effect of dopaminergic manipulations on timing behavior might also be independently mediated by altered motivational state. Studies that investigated the effect of motivational manipulations on peak responding are reviewed in this paper. The majority of these studies show that a higher reward...

  2. Unsupervised clustering of Type II supernova light curves

    CERN Document Server

    Rubin, Adam

    2016-01-01

    As new facilities come online, the astronomical community will be provided with extremely large datasets of well-sampled light curves (LCs) of transient objects. This motivates systematic studies of the light curves of supernovae (SNe) of all types, including the early rising phase. We performed unsupervised k-means clustering on a sample of 59 R-band Type II SN light curves and find that our sample can be divided into three classes: slowly-rising (II-S), fast-rise/slow-decline (II-FS), and fast-rise/fast-decline (II-FF). We also identify three outliers based on the algorithm. We find that performing clustering on the first two components of a principle component analysis gives equivalent results to the analysis using the full LC morphologies. This may indicate that Type II LCs could possibly be reduced to two parameters. We present several important caveats to the technique, and find that the division into these classes is not fully robust and is sensitive to the uncertainty on the time of first light. Moreo...

  3. Whitney's formulas for curves on surfaces

    CERN Document Server

    Burman, Yurii

    2009-01-01

    The classical Whitney formula relates the number of times an oriented plane curve cuts itself to its rotation number and the index of a base point. In this paper we generalize Whitney's formula to curves on an oriented punctured surface. To define analogs of the rotation number and the index of a base point of a curve, we fix an arbitrary vector field on the surface. Similar formulas are obtained for non-based curves.

  4. RECOGNIZING MOTIVES: THE DISSENSUAL SELF

    DEFF Research Database (Denmark)

    Nissen, Morten; Christensen, Tine Friis

    2017-01-01

    , these technologies confirm a common-sense, managerial self; others read them as a ‘poetics of practice’ that performs and produces new motives and selves in a liminal space of discursive creativity. These two readings are superseded as we – with art theory from Vygotsky through Brecht to Groys, Bourriaud...... that reconfigures sense and meaning, can play a part. This chapter aims at suggesting these potentials by rearticulating activities in which people display (represent, avow, reflect, expose, externalize, etc.) their motives. Most contemporary ‘motivational technologies’ stage a pragmatic self-calculation. For some...... emerging selves, senses, and motives....

  5. Gelfond–Bézier curves

    KAUST Repository

    Ait-Haddou, Rachid

    2013-02-01

    We show that the generalized Bernstein bases in Müntz spaces defined by Hirschman and Widder (1949) and extended by Gelfond (1950) can be obtained as pointwise limits of the Chebyshev–Bernstein bases in Müntz spaces with respect to an interval [a,1][a,1] as the positive real number a converges to zero. Such a realization allows for concepts of curve design such as de Casteljau algorithm, blossom, dimension elevation to be transferred from the general theory of Chebyshev blossoms in Müntz spaces to these generalized Bernstein bases that we termed here as Gelfond–Bernstein bases. The advantage of working with Gelfond–Bernstein bases lies in the simplicity of the obtained concepts and algorithms as compared to their Chebyshev–Bernstein bases counterparts.

  6. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  7. Counting rational points on cubic curves

    Institute of Scientific and Technical Information of China (English)

    HEATH-BROWN; Roger; TESTA; Damiano

    2010-01-01

    We prove upper bounds for the number of rational points on non-singular cubic curves defined over the rationals.The bounds are uniform in the curve and involve the rank of the corresponding Jacobian.The method used in the proof is a combination of the "determinant method" with an m-descent on the curve.

  8. Optimal investment in learning-curve technologies

    NARCIS (Netherlands)

    Della Seta, M.; Gryglewicz, S.; Kort, P.M.

    2012-01-01

    We study optimal investment in technologies characterized by the learning curve. There are two investment patterns depending on the shape of the learning curve. If the learning process is slow, firms invest relatively late and on a larger scale. If the curve is steep, firms invest earlier and on a s

  9. A STUDY ON JIG DISTRIBUTION CURVE TRANSFORMATION

    Institute of Scientific and Technical Information of China (English)

    路迈西; 常大山; 郭珍旭

    1991-01-01

    An investigation of the errors resulted from distribution curve transformations using six different methods was made on the basis of 61 sets of jig performance test data from the coal preparation plants in China. The results indicate that minimum error occurred when distribution curves were transformed by keeping imperfection I constant. Generalized distribution curves are developed for jigs and their applications are discussed.

  10. The Bezout Number of Piecewise Algebraic Curves

    Institute of Scientific and Technical Information of China (English)

    Dian Xuan GONG; Ren Hong WANG

    2012-01-01

    Based on the discussion of the number of roots of univariate spline and the common zero points of two piecewise algebraic curves,a lower upbound of Bezout number of two piecewise algebraic curves on any given non-obtuse-angled triangulation is found.Bezout number of two piecewise algebraic curves on two different partitions is also discussed in this paper.

  11. Automated Blazar Light Curves Using Machine Learning

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Spencer James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-27

    This presentation describes a problem and methodology pertaining to automated blazar light curves. Namely, optical variability patterns for blazars require the construction of light curves and in order to generate the light curves, data must be filtered before processing to ensure quality.

  12. AKLSQF - LEAST SQUARES CURVE FITTING

    Science.gov (United States)

    Kantak, A. V.

    1994-01-01

    The Least Squares Curve Fitting program, AKLSQF, computes the polynomial which will least square fit uniformly spaced data easily and efficiently. The program allows the user to specify the tolerable least squares error in the fitting or allows the user to specify the polynomial degree. In both cases AKLSQF returns the polynomial and the actual least squares fit error incurred in the operation. The data may be supplied to the routine either by direct keyboard entry or via a file. AKLSQF produces the least squares polynomial in two steps. First, the data points are least squares fitted using the orthogonal factorial polynomials. The result is then reduced to a regular polynomial using Sterling numbers of the first kind. If an error tolerance is specified, the program starts with a polynomial of degree 1 and computes the least squares fit error. The degree of the polynomial used for fitting is then increased successively until the error criterion specified by the user is met. At every step the polynomial as well as the least squares fitting error is printed to the screen. In general, the program can produce a curve fitting up to a 100 degree polynomial. All computations in the program are carried out under Double Precision format for real numbers and under long integer format for integers to provide the maximum accuracy possible. AKLSQF was written for an IBM PC X/AT or compatible using Microsoft's Quick Basic compiler. It has been implemented under DOS 3.2.1 using 23K of RAM. AKLSQF was developed in 1989.

  13. Caloric curve of star clusters.

    Science.gov (United States)

    Casetti, Lapo; Nardini, Cesare

    2012-06-01

    Self-gravitating systems, such as globular clusters or elliptical galaxies, are the prototypes of many-body systems with long-range interactions, and should be the natural arena in which to test theoretical predictions on the statistical behavior of long-range-interacting systems. Systems of classical self-gravitating particles can be studied with the standard tools of equilibrium statistical mechanics, provided the potential is regularized at small length scales and the system is confined in a box. The confinement condition looks rather unphysical in general, so that it is natural to ask whether what we learn with these studies is relevant to real self-gravitating systems. In order to provide an answer to this question, we consider a basic, simple, yet effective model of globular clusters: the King model. This model describes a self-consistently confined system, without the need of any external box, but the stationary state is a nonthermal one. In particular, we consider the King model with a short-distance cutoff on the interactions, and we discuss how such a cutoff affects the caloric curve, i.e., the relation between temperature and energy. We find that the cutoff stabilizes a low-energy phase, which is absent in the King model without cutoff; the caloric curve of the model with cutoff turns out to be very similar to that of previously studied confined and regularized models, but for the absence of a high-energy gaslike phase. We briefly discuss the possible phenomenological as well as theoretical implications of these results.

  14. What Motivates the Motivators? An Examination of Sports Coaches

    Science.gov (United States)

    McLean, Kristy N.; Mallett, Clifford J.

    2012-01-01

    Background: Motivation is central to successful performance. In the case of sports coaches, drive is a prerequisite to sustained successful engagement in a complex, dynamic, and turbulent work environment. What fuels these coaches' drive to pursue this vocational activity? Coach motivation has been underrepresented in previous research which has…

  15. Directed Motivational Currents: Using Vision to Create Effective Motivational Pathways

    Science.gov (United States)

    Muir, Christine; Dörnyei, Zoltán

    2013-01-01

    Vision, that is, the mental representation of the sensory experience of a future goal state (involving imagination and imagery), is currently at the forefront of motivational innovation, and in recent years it has been seen increasingly more often in the motivational tool kit of practicing language teachers. Theories such as Dörnyei's L2…

  16. Motivation and Creativity: Effects of Motivational Orientation on Creative Writers.

    Science.gov (United States)

    Amabile, Teresa M.

    This study directly tested the hypothesis that intrinsic motivation is conducive to creativity and extrinsic motivation is detrimental. Chosen because they identified themselves as actively involved in creative writing, 72 young adults participated in individual laboratory sessions where they were asked to write two brief poems. Before writing the…

  17. [Team motivation and motivational strategies adopted by nurses].

    Science.gov (United States)

    Bezerra, Felipa Daiana; Andrade, Marta Francisca da Conceição; Andrade, Joseilze Santos de; Vieira, Maria Jésia; Pimentel, Deborah

    2010-01-01

    Qualitative study held in an emergency hospital in Aracaju-SE, which aimed to know the perception of nurses about what is a motivated nursing team, to identify possible motivational policies used by them and if they are consistent with the policies proposed by Frederick Herzberg in his theory. Of the 20 nurses participants, the most understood the motivation as a set of techniques possible to shape the behavior of the individual at work, linking it to extrinsic factors and 60% did not consider his team motivated. The types of motivational policies that usually apply realized that these correspond to intrinsic factors aimed at self recovery and self realization of individuals in the tasks running.

  18. Modeling motive activation in the Operant Motives Test

    DEFF Research Database (Denmark)

    Runge, J. Malte; Lang, Jonas W. B.; Engeser, Stefan

    2016-01-01

    The Operant Motive Test (OMT) is a picture-based procedure that asks respondents to generate imaginative verbal behavior that is later coded for the presence of affiliation, power, and achievement-related motive content by trained coders. The OMT uses a larger number of pictures and asks...... respondents to provide more brief answers than earlier and more traditional picture-based implicit motive measures and has therefore become a frequently used measurement instrument in both research and practice. This article focuses on the psychometric response mechanism in the OMT and builds on recent...... measures (Lang, 2014) and reports the first analysis of which we are aware that applies this model to OMT data (N = 633) and studies dynamic motive activation in the OMT. Results of this analysis yielded evidence for dynamic motive activation in the OMT and showed that simulated IRT reliabilities based...

  19. Relative acceleration approach for conduction failure of cardiac excitation propagation on anisotropic curved surfaces

    CERN Document Server

    Chun, Sehun

    2012-01-01

    In cardiac electrophysiology, it is important to predict the necessary conditions for conduction failure, the failure of the cardiac excitation propagation even in the presence of normal excitable tissue, in high-dimensional anisotropic space because these conditions may provide feasible mechanisms for abnormal excitation propagations such as atrial re-entry and, subsequently, atrial fibrillation even without taking into account the time-dependent refractory region. Some conditions of conduction failure have been studied for anisotropy or simple curved surfaces, but the general conditions on anisotropic curved surfaces (anisotropic and curved surface) remain unknown. To predict and analyze conduction failure on anisotropic curved surfaces, a new analytic approach is proposed, called the relative acceleration approach borrowed from spacetime physics. Motivated by a discrete model of cardiac excitation propagation, this approach is based on the hypothesis that a large relative acceleration can translate to a dr...

  20. Method of construction spatial transition curve

    Directory of Open Access Journals (Sweden)

    S.V. Didanov

    2013-04-01

    Full Text Available Purpose. The movement of rail transport (speed rolling stock, traffic safety, etc. is largely dependent on the quality of the track. In this case, a special role is the transition curve, which ensures smooth insertion of the transition from linear to circular section of road. The article deals with modeling of spatial transition curve based on the parabolic distribution of the curvature and torsion. This is a continuation of research conducted by the authors regarding the spatial modeling of curved contours. Methodology. Construction of the spatial transition curve is numerical methods for solving nonlinear integral equations, where the initial data are taken coordinate the starting and ending points of the curve of the future, and the inclination of the tangent and the deviation of the curve from the tangent plane at these points. System solutions for the numerical method are the partial derivatives of the equations of the unknown parameters of the law of change of torsion and length of the transition curve. Findings. The parametric equations of the spatial transition curve are calculated by finding the unknown coefficients of the parabolic distribution of the curvature and torsion, as well as the spatial length of the transition curve. Originality. A method for constructing the spatial transition curve is devised, and based on this software geometric modeling spatial transition curves of railway track with specified deviations of the curve from the tangent plane. Practical value. The resulting curve can be applied in any sector of the economy, where it is necessary to ensure a smooth transition from linear to circular section of the curved space bypass. An example is the transition curve in the construction of the railway line, road, pipe, profile, flat section of the working blades of the turbine and compressor, the ship, plane, car, etc.

  1. Cubic Curves, Finite Geometry and Cryptography

    CERN Document Server

    Bruen, A A; Wehlau, D L

    2011-01-01

    Some geometry on non-singular cubic curves, mainly over finite fields, is surveyed. Such a curve has 9,3,1 or 0 points of inflexion, and cubic curves are classified accordingly. The group structure and the possible numbers of rational points are also surveyed. A possible strengthening of the security of elliptic curve cryptography is proposed using a `shared secret' related to the group law. Cubic curves are also used in a new way to construct sets of points having various combinatorial and geometric properties that are of particular interest in finite Desarguesian planes.

  2. On Self-growing Modeling for Curves

    Institute of Scientific and Technical Information of China (English)

    HUANG Dong-zhao; ZHU Zhi-hong; ZHOU Hui-cheng; SHI Han-min

    2008-01-01

    This paperpresents a novel curoe modeling method based on controlling rules of the shaping technique.The method describes the curve based on steplength and turning angle,and the characteristics of the curve near a point.Then it introduces the process to extract" growing-rules"for 2D and 3D curves described by familiar analytical expressions and curvature-torsion expressions.Examples of selfgrowing modeling for familiar analytical curves are presented.New curves are obtained by designing the grow-rules;corresponding examples are also presented.

  3. Koch Curves: Rewriting System, Geometry and Application

    Directory of Open Access Journals (Sweden)

    Mamta Rani

    2011-01-01

    Full Text Available Problem statement: Recently, new Koch curves have been generated by dividing the initiator into three unequal parts. There is no formal rewriting system to generate such kind of curves. Approach: It is required to measure the new changed geometrical properties. Generalized rewriting systems for the new Koch curves have been developed. Results: New formulas have been given to measure their geometrical properties. Conclusion/Recommendations: The geometrical properties of new Koch curves make them more suitable as antennas in wireless communication than the conventional Koch curve.

  4. Logistical Factors in Teachers' Motivation

    Science.gov (United States)

    Daniels, Erika

    2016-01-01

    Research in education and psychology contributes to an understanding of how educators create contexts for learning that encourage intrinsic motivation and increase academic achievement. In this article, the researcher investigated how teachers themselves define effectiveness and identified what factors influence their motivation, both positively…

  5. Intrinsic Motivation in Physical Education

    Science.gov (United States)

    Davies, Benjamin; Nambiar, Nathan; Hemphill, Caroline; Devietti, Elizabeth; Massengale, Alexandra; McCredie, Patrick

    2015-01-01

    This article describes ways in which educators can use Harter's perceived competence motivation theory, the achievement goal theory, and self-determination theory to develop students' intrinsic motivation to maintain physical fitness, as demonstrated by the Sound Body Sound Mind curriculum and proven effective by the 2013 University of…

  6. Motivational Issues in Knowledge Work

    Directory of Open Access Journals (Sweden)

    Anca BOGDAN

    2008-01-01

    Full Text Available The paper discusses the place of emotions in modern theories of motivation, and the influence of the knowledge-oriented paradigm on redefining motivation and rethinking ways of rendering work, knowledge work, in particular, more efficient, in a society in which human participation and deployment of intellectual capital become key factors of success, replacing traditional, tangible-focused, factors of production.

  7. Home education: The social motivation

    Directory of Open Access Journals (Sweden)

    Christian W. BECK

    2010-10-01

    Full Text Available Data from a Norwegian survey show correlation between a student’s socially related problems at school and the parent’s social motivation for home education. I argue that more time spent at school by a student could result in more socially related problems at school, which can explain an increase in social motivation for home education.

  8. Gender Differences in Moral Motivation

    Science.gov (United States)

    Nunner-Winkler, Gertrud; Meyer-Nikele, Marion; Wohlrab, Doris

    2007-01-01

    Moral gender differences have been discussed in terms of Kohlbergian stages and content of orientations and taken to correspond to universal stable male and female features. The present study instead focuses on moral motivation and explains differences in terms of role expectations. We assessed moral motivation in 203 adolescents by a newly…

  9. Motivating young people for education

    DEFF Research Database (Denmark)

    Cort, Pia

    2013-01-01

    The article explores the issue of motivation in policy and practice. The argument is that the folk high schools and the tradition of liberal education offer a learning environment where a number of psychological needs are satisfied among the young people leading to a motivation for learning whereas...

  10. Client Motivation and Multicultural Counseling

    Science.gov (United States)

    Kim, Bryan S. K.

    2011-01-01

    This reaction article comments on the major contribution titled "Motivation and Autonomy in Counseling, Psychotherapy, and Behavior Change: A Look at Theory and Practice." It first points out the article's strengths, the primary of which was to move the construct of motivation to the center of focus in the discussion of counseling. In addition,…

  11. Home education: The social motivation

    OpenAIRE

    Christian W. Beck

    2010-01-01

    Data from a Norwegian survey show correlation between a student’s socially related problems at school and the parent’s social motivation for home education. I argue that more time spent at school by a student could result in more socially related problems at school, which can explain an increase in social motivation for home education.

  12. Motivation and Second Language Learning

    Institute of Scientific and Technical Information of China (English)

    郭建业

    2007-01-01

    Motivation, which is one of the individual differences, contributes a lot to the success and failure in second language learning. This essay focus on the discussion of the definition, types, effect and implications of motivation in second language learning with the aim of promoting learners' learning proficiency.

  13. Management problems of staff motivation

    OpenAIRE

    PUZYNYA T.A.

    2015-01-01

    Staff motivation is a major link in improving the competitiveness of any organization. One of the main problems of management of motivation of staff is the individuality of each employee, so the knowledge of psychology and individual needs will help organizations effectively manage staff.

  14. Motivational Profiles of Adult Learners

    Science.gov (United States)

    Rothes, Ana; Lemos, Marina S.; Gonçalves, Teresa

    2017-01-01

    This study investigated profiles of autonomous and controlled motivation and their effects in a sample of 188 adult learners from two Portuguese urban areas. Using a person-centered approach, results of cluster analysis and multivariate analysis of covariance revealed four motivational groups with different effects in self-efficacy, engagement,…

  15. Management problems of staff motivation

    OpenAIRE

    PUZYNYA T.A.

    2015-01-01

    Staff motivation is a major link in improving the competitiveness of any organization. One of the main problems of management of motivation of staff is the individuality of each employee, so the knowledge of psychology and individual needs will help organizations effectively manage staff.

  16. Midwives' Motivation for Continuing Education.

    Science.gov (United States)

    Laszlo, Halldora; Strettle, Robert J.

    1996-01-01

    Responses from 83 of 120 British midwives showed that motivation for continuing education was strongest in regard to professional competence and innate desire for knowledge, less in regard to legal requirements for practice. Strongest motivators were internal and learning related. Social integration was the least important aspect of continuing…

  17. Logistical Factors in Teachers' Motivation

    Science.gov (United States)

    Daniels, Erika

    2016-01-01

    Research in education and psychology contributes to an understanding of how educators create contexts for learning that encourage intrinsic motivation and increase academic achievement. In this article, the researcher investigated how teachers themselves define effectiveness and identified what factors influence their motivation, both positively…

  18. Home Education: The Social Motivation

    Science.gov (United States)

    Beck, Christian W.

    2010-01-01

    Data from a Norwegian survey show correlation between a student's socially related problems at school and the parent's social motivation for home education. I argue that more time spent at school by a student could result in more socially related problems at school, which can explain an increase in social motivation for home education.

  19. Power is the Great Motivator

    Science.gov (United States)

    McClelland, David C.; Burnham, David H.

    1976-01-01

    Empirical research shows good managers are motivated by a need for power, tempered by maturity and self-control. Workshops can help a manager discover whether he has the correct motivation profile and can help him become a better manager. (JG)

  20. Power is the Great Motivator

    Science.gov (United States)

    McClelland, David C.; Burnham, David H.

    1976-01-01

    Empirical research shows good managers are motivated by a need for power, tempered by maturity and self-control. Workshops can help a manager discover whether he has the correct motivation profile and can help him become a better manager. (JG)

  1. POSITIVE MOTIVATION DETERMINANTS IN PSYCHOLOGY

    Directory of Open Access Journals (Sweden)

    Svyatoslav Vasilyevich KOTOV

    2014-01-01

    Full Text Available The paper considered the study of determinants of moti-vation and operation achievement. The paper revealed (with description in details the following factors: want for competence and self-determination, orientation in purpose of live, values, self-efficacy, resilience, and in-trinsic motivation. The study rationalized psychology regularities in the above determinants and the part they played in shaping resilience, personal mental wellbeing and further reinforcement of achievement motivation where the levels at the value scale of an individual served for the basis, those described in details in this paper. All the above determinants of positive motivation enable the individual to get over inner personal tensions, to become an autotelic free person. This paper reviewed the deter-minants of positive motivation in both Russian and for-eign studies of psychologists.

  2. Sustaining motivation for continuous improvement

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Kofoed, Lise Busk

    2007-01-01

    activities is an important issue for managers. The paper begins with a short description of CI, with an emphasis on barriers to successful implementation cited in the literature. Thereafter, a number of widely-acknowledged-albeit perhaps somewhat dated-theories of motivation are explored in relation...... to the elements of CI in practice. Based on their own experiences with CI implementation in numerous action-research based studies, the authors propose a scenario for motivating CI participation through emphasis on factors common to the presented motivational theories. The paper ends with insights into future...... for managers to motivate participation in CI. Further the paper contributes to development of CI theory by suggesting how elements of motivation theory may address the most common types of barriers to successful CI....

  3. Sustaining motivation for continuous improvement

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Kofoed, Lise Busk

    2007-01-01

    activities is an important issue for managers. The paper begins with a short description of CI, with an emphasis on barriers to successful implementation cited in the literature. Thereafter, a number of widely-acknowledged-albeit perhaps somewhat dated-theories of motivation are explored in relation...... to the elements of CI in practice. Based on their own experiences with CI implementation in numerous action-research based studies, the authors propose a scenario for motivating CI participation through emphasis on factors common to the presented motivational theories. The paper ends with insights into future...... for managers to motivate participation in CI. Further the paper contributes to development of CI theory by suggesting how elements of motivation theory may address the most common types of barriers to successful CI....

  4. Motivational Interviewing by School Nurses

    DEFF Research Database (Denmark)

    Bonde, Ane; Bentsen, Peter; Hindhede, Anette Lykke

    Interviewing. Second Edition. London. SAGE.Miller, W.R. & Rollnick, S. (1995). What is Motivational interviewing? Behavioural and Cognitive Psychotherapy, 23(4), 325-34.Miller, W.R. & Rose, G.S. (2009). Toward a Theory of Motivational interviewing. American Psychologist, 64(6), 527-537. Morrison-Sandberg, L......Title: Motivational Interviewing by School Nurses: Spirit, Techniques, and Dilemmas in the Prevention of Child Obesity Introduction : School nurses play a central role in school-based, preventive health services in Denmark (National Board of Health, 2011), and they may play an important role...... a prevention strategy targeting children with a high risk of obesity with an intervention conducted by school nurses using motivational interviewing.Motivational interviewing is a counselling method to bring about behavioural change (Miller and Rollnick 1995). Effect has been documented for a range of problem...

  5. Evaluation and motivation of human resources

    Directory of Open Access Journals (Sweden)

    Guga, L.

    2012-01-01

    Full Text Available Why do we need motivated employees? The answer is survival. Motivated employees are needed in our rapidly changing workplaces. Motivated employees help organizations survive. Motivated employees are more productive. To be effective, managers need to understand what motivates employees within the context of the roles they perform.

  6. Philanthropic behaviour and motives

    Directory of Open Access Journals (Sweden)

    Vladimír Hyánek

    2013-01-01

    Full Text Available Even though philanthropy tends to be considered a sociological theme rather than an economic one, it poses a number of questions that challenge economists as well. We chose to address the following: How can economists contribute to the theories related to philanthropy? We examine some terms that are used in public economics theory and use them to explore the issues of philanthropy like Samaritan’s Dilemma, the Prisoner’s Dilemma, and the Free-Rider Problem, which we consider to be interesting and inspiring (Stone, 2008. We have to find and identify the social values of donors and volunteers rather than their economic values, because economists are not fully able to explain empathy, altruism, and helpful behaviour using traditional economic principles (Rutherford, 2008. The theoretical frame is supported by relevant empirical data. Before starting a large-scale survey, we decided to conduct smaller pre-research probes into people’s attitudes towards altruism, philanthropy, and giving. Even though our sample was not fully representative, the responses that we collected generated interesting findings about people’s views and attitudes. The first wave of data was collected between February and April 2009; the second wave between February and April 2010.Because of this pilot research mission and because of the budget restriction too, the non-representative sample of 823 respondents has been used; students of our Public Economics study programme were used as interviewers. They have also obtained a proper training of the professional sociologist. Students utilized the face to face interviewing method; non-standardized questions were immediately recorded into the reply form. Questions were divided into three groups with typical characteristics. The first one focuses on personal (individual motives for financial donating (only financial gifts for non-profit organizations. Second part examines the attitudes of individual towards the non

  7. Is the tautochrone curve unique?

    CERN Document Server

    Terra, Pedro; Farina, C

    2016-01-01

    The answer to this question is no. In fact, in addition to the solution first obtained by Christiaan Huygens in 1658, given by the cycloid, we show that there is an infinite number of tautochrone curves. With this goal, we start by briefly reviewing an the problem of finding out the possible potential energies that lead to periodic motions of a particle whose period is a given function of its mechanical energy. There are infinitely many solutions, called sheared potentials. As an interesting example, we show that a P\\"oschl-Teller and the one-dimensional Morse potentials are sheared relative to one another for negative energies, clarifying why they share the same periods of oscillations for their bounded solutions. We then consider periodic motions of a particle sliding without friction over a track around its minimum under the influence of an uniform gravitational field. After a brief historical survey of the tautochrone problem we show that, given the period of oscillations, there is an infinity of tracks w...

  8. Is the tautochrone curve unique?

    Science.gov (United States)

    Terra, Pedro; de Melo e Souza, Reinaldo; Farina, C.

    2016-12-01

    We show that there are an infinite number of tautochrone curves in addition to the cycloid solution first obtained by Christiaan Huygens in 1658. We begin by reviewing the inverse problem of finding the possible potential energy functions that lead to periodic motions of a particle whose period is a given function of its mechanical energy. There are infinitely many such solutions, called "sheared" potentials. As an interesting example, we show that a Pöschl-Teller potential and the one-dimensional Morse potentials are sheared relative to one another for negative energies, clarifying why they share the same oscillation periods for their bounded solutions. We then consider periodic motions of a particle sliding without friction over a track around its minimum under the influence of a constant gravitational field. After a brief historical survey of the tautochrone problem we show that, given the oscillation period, there is an infinity of tracks that lead to the same period. As a bonus, we show that there are infinitely many tautochrones.

  9. Algebraic points on meromorphic curves

    CERN Document Server

    Herblot, Mathilde

    2012-01-01

    The classic Schneider-Lang theorem in transcendence theory asserts that there are only finitely many points at which algebraically independent complex meromorphic functions of finite order of growth can simultaneously take values in a number field, when satisfying a polynomial differential equation with coefficients in this given number field. In this article, we are interested in generalizing this theorem in two directions. First, instead of considering meromorphic functions on C we consider holomorphic maps on an affine curve over the field C or C_p. This extends a statement of D. Bertrand, which applies to meromorphic functions on P^1(C) or P^1(C_p) minus a finite subset of points. Secondly, we deal with algebraic values taken by the functions, instead of rational values as in the classic setting, inspired by a work of D. Bertrand. We prove a geometric statement extending those two results, using the slopes method, written in the language of Arakelov geometry. In the complex case, we recover a special case...

  10. Quantum fields in curved spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Hollands, Stefan, E-mail: stefan.hollands@uni-leipzig.de [Universität Leipzig, Institut für Theoretische Physik, Brüderstrasse 16, D-04103 Leipzig (Germany); Wald, Robert M., E-mail: rmwa@uchicago.edu [Enrico Fermi Institute and Department of Physics, University of Chicago, Chicago, IL 60637 (United States)

    2015-04-16

    We review the theory of quantum fields propagating in an arbitrary, classical, globally hyperbolic spacetime. Our review emphasizes the conceptual issues arising in the formulation of the theory and presents known results in a mathematically precise way. Particular attention is paid to the distributional nature of quantum fields, to their local and covariant character, and to microlocal spectrum conditions satisfied by physically reasonable states. We review the Unruh and Hawking effects for free fields, as well as the behavior of free fields in deSitter spacetime and FLRW spacetimes with an exponential phase of expansion. We review how nonlinear observables of a free field, such as the stress–energy tensor, are defined, as well as time-ordered-products. The “renormalization ambiguities” involved in the definition of time-ordered products are fully characterized. Interacting fields are then perturbatively constructed. Our main focus is on the theory of a scalar field, but a brief discussion of gauge fields is included. We conclude with a brief discussion of a possible approach towards a nonperturbative formulation of quantum field theory in curved spacetime and some remarks on the formulation of quantum gravity.

  11. Simulations of Closed Timelike Curves

    Science.gov (United States)

    Brun, Todd A.; Wilde, Mark M.

    2017-03-01

    Proposed models of closed timelike curves (CTCs) have been shown to enable powerful information-processing protocols. We examine the simulation of models of CTCs both by other models of CTCs and by physical systems without access to CTCs. We prove that the recently proposed transition probability CTCs (T-CTCs) are physically equivalent to postselection CTCs (P-CTCs), in the sense that one model can simulate the other with reasonable overhead. As a consequence, their information-processing capabilities are equivalent. We also describe a method for quantum computers to simulate Deutschian CTCs (but with a reasonable overhead only in some cases). In cases for which the overhead is reasonable, it might be possible to perform the simulation in a table-top experiment. This approach has the benefit of resolving some ambiguities associated with the equivalent circuit model of Ralph et al. Furthermore, we provide an explicit form for the state of the CTC system such that it is a maximum-entropy state, as prescribed by Deutsch.

  12. Drinking motives and links to alcohol use in 13 European countries

    DEFF Research Database (Denmark)

    Kuntsche, Emmanuel; Gabhainn, Saoirse Nic; Roberts, Chris

    2014-01-01

    , based on a sample of 33,813 alcohol-using students from Belgium, Denmark, Estonia, Finland, Hungary, Ireland, Italy, Poland, Portugal, Scotland, Slovakia, Switzerland, and Wales who completed the Drinking Motives Questionnaire Revised Short Form (DMQ-R SF). Results: The findings confirmed......ABSTRACT. Objective: The purpose of this study was to test the structure and endorsement of drinking motives and their links to alcohol use among 11- to 19-year-olds from 13 European countries. Method: Confirmatory factor analysis, latent growth curves, and multiple regression models were conducted...... European countries. The results confirmed that, across countries, social motives were strongly positively related to drinking frequency, enhancement motives were strongly positively related to frequency of drunkenness, and conformity motives were negatively related to both alcohol outcomes. Against our...

  13. NormaCurve: a SuperCurve-based method that simultaneously quantifies and normalizes reverse phase protein array data.

    Directory of Open Access Journals (Sweden)

    Sylvie Troncale

    Full Text Available MOTIVATION: Reverse phase protein array (RPPA is a powerful dot-blot technology that allows studying protein expression levels as well as post-translational modifications in a large number of samples simultaneously. Yet, correct interpretation of RPPA data has remained a major challenge for its broad-scale application and its translation into clinical research. Satisfying quantification tools are available to assess a relative protein expression level from a serial dilution curve. However, appropriate tools allowing the normalization of the data for external sources of variation are currently missing. RESULTS: Here we propose a new method, called NormaCurve, that allows simultaneous quantification and normalization of RPPA data. For this, we modified the quantification method SuperCurve in order to include normalization for (i background fluorescence, (ii variation in the total amount of spotted protein and (iii spatial bias on the arrays. Using a spike-in design with a purified protein, we test the capacity of different models to properly estimate normalized relative expression levels. The best performing model, NormaCurve, takes into account a negative control array without primary antibody, an array stained with a total protein stain and spatial covariates. We show that this normalization is reproducible and we discuss the number of serial dilutions and the number of replicates that are required to obtain robust data. We thus provide a ready-to-use method for reliable and reproducible normalization of RPPA data, which should facilitate the interpretation and the development of this promising technology. AVAILABILITY: The raw data, the scripts and the normacurve package are available at the following web site: http://microarrays.curie.fr.

  14. Certified Approximation of Parametric Space Curves with Cubic B-spline Curves

    CERN Document Server

    Shen, Liyong; Gao, Xiao-Shan

    2012-01-01

    Approximating complex curves with simple parametric curves is widely used in CAGD, CG, and CNC. This paper presents an algorithm to compute a certified approximation to a given parametric space curve with cubic B-spline curves. By certified, we mean that the approximation can approximate the given curve to any given precision and preserve the geometric features of the given curve such as the topology, singular points, etc. The approximated curve is divided into segments called quasi-cubic B\\'{e}zier curve segments which have properties similar to a cubic rational B\\'{e}zier curve. And the approximate curve is naturally constructed as the associated cubic rational B\\'{e}zier curve of the control tetrahedron of a quasi-cubic curve. A novel optimization method is proposed to select proper weights in the cubic rational B\\'{e}zier curve to approximate the given curve. The error of the approximation is controlled by the size of its tetrahedron, which converges to zero by subdividing the curve segments. As an applic...

  15. Harnessing motivation to alleviate neglect

    Directory of Open Access Journals (Sweden)

    Charlotte eRussell

    2013-06-01

    Full Text Available The syndrome of spatial neglect results from the combination of a number of deficits in attention, with patients demonstrating both spatially lateralised and non-lateralised impairments. Previous reports have hinted that there may be a motivational component to neglect and that modulating this might alleviate some of the debilitating symptoms. Additionally, recent work on the effects of reward on attention in healthy participants has revealed improvements across a number of paradigms. As the primary deficit in neglect has been associated with attention, this evidence for reward’s effects is potentially important. However, until very recently there have been few empirical studies addressing this potential therapeutic avenue. Here we review the growing body of evidence that attentional impairments in neglect can be reduced by motivation, for example in the form of preferred music or anticipated monetary reward, and discuss the implications of this for treatments for these patients. Crucially these effects of positive motivation are not observed in all patients with neglect, suggesting that the consequences of motivation may relate to individual lesion anatomy. Given the key role of dopaminergic systems in motivational processes, we suggest that motivational stimulation might act as a surrogate for dopaminergic stimulation. In addition, we consider the relationship between clinical post stroke apathy and lack of response to motivation.

  16. Harnessing motivation to alleviate neglect.

    Science.gov (United States)

    Russell, Charlotte; Li, Korina; Malhotra, Paresh A

    2013-01-01

    The syndrome of spatial neglect results from the combination of a number of deficits in attention, with patients demonstrating both spatially lateralized and non-lateralized impairments. Previous reports have hinted that there may be a motivational component to neglect and that modulating this might alleviate some of the debilitating symptoms. Additionally, recent work on the effects of reward on attention in healthy participants has revealed improvements across a number of paradigms. As the primary deficit in neglect has been associated with attention, this evidence for reward's effects is potentially important. However, until very recently there have been few empirical studies addressing this potential therapeutic avenue. Here we review the growing body of evidence that attentional impairments in neglect can be reduced by motivation, for example in the form of preferred music or anticipated monetary reward, and discuss the implications of this for treatments for these patients. Crucially these effects of positive motivation are not observed in all patients with neglect, suggesting that the consequences of motivation may relate to individual lesion anatomy. Given the key role of dopaminergic systems in motivational processes, we suggest that motivational stimulation might act as a surrogate for dopaminergic stimulation. In addition, we consider the relationship between clinical post stroke apathy and lack of response to motivation.

  17. How Do We Motivate Reading Comprehension?

    Science.gov (United States)

    Shanahan, Timothy

    1982-01-01

    Considers the nature of motivation and its place in the development of reading comprehension. Uses A. Maslow's hierarchy of motivation as a heuristic for examining the motivational quality of several teaching methods commonly proposed for comprehension instruction. (FL)

  18. Conceptual grounds to form motivational constituent of the international ecological policy

    Directory of Open Access Journals (Sweden)

    O.V. Prokopenko

    2015-12-01

    Full Text Available The aim of the article. The aim of the article is to develop scientific and methodic grounds to form motivational constituent of the international ecological policy. The results of the analysis. Directions to improve activity and efficiency of the international ecological policy consist in improvement or change of the existing elements in natural management mechanism, forms and tools of ecopolicy. Therefore motivating mechanism of environmental protection and rational natural management has prior value. One of the main points to form motivating tools system has to be increasing of the economic activity total efficiency in the country. Its achievement depends on ratio between change in efficiency of the ecodestructive and ecologically oriented innovative activity. Authors present graphically and ground possible variants of innovative activity efficiency while using economic motivating tools of its ecologization. Authors also suggest to use curve, which describes inequality of ecodestructive impact distinguish, to determine perspectives for innovative activity ecologization motivating creation in the country. The proposed methodic approach is used only to analyze enterprises ecological compatibility, which has destructive impact on environment. Inequality coefficient is suggested to measure degree of ecodestructive impact distinguish inequality degree. Authors investigated principle scheme to define potential of innovative activity ecologization motivating depending on the received inequality coefficient of the ecodestructive impact distinguish and type of the distinguish curve. In order to avoid subjectivity of ecodestructive impact distinguish curve one suggests to use formalized procedure, which foresees determination of distinguish curve type by results of shifting coefficient calculation. In order to form efficient system of the innovative activity ecologization motivating one proposes to use developed map of the relative socio

  19. Students’ Motivation in Speaking English

    Directory of Open Access Journals (Sweden)

    Mas Darul Ihsan

    2016-05-01

    Full Text Available As the English teacher in the classroom, there will be some problems or conditions need to be accomplished. Teacher will see some of the students are very motivated, motivated or even feeling ignored in studying English. The learners who have contacted with English will find that some features are quite easy and extremely difficult. One of the more complicated problems of second or foreign languages learning and  teaching has been to define and apply the construct of motivation in the classroom. Motivation is a concept without physical reality, we cannot see motivation; we see effort, interest, attitude and desire. For speaking, it is important first to give competence and then performance. Competence is more likely to the extent a communicator is motivated to be so. Motivation is the extent to which a communicator is drawn towards or pushed away from communicating competently in a given context then performed. This is a descriptive  quantitative research. The data obtained from the questionnaire distributed and analyzed to get the result.  The date taken from the students of Muhammadiyah 1 Senior High School Gresik in Easy-Speaking course. The researcher wanted to know the students’ motivation in practicing speaking English in Easy-Speaking course. The results show that 1 the learners effort in practicing speaking English is 56.1 %. 2 The learners’ interest in practicing speaking English is 49.7 %. 3 The learners’ attitude towards practicing speaking English is 59.9 %. 4 The learners’ desire in practicing speaking English is 71.43 %. Then, some suggestions are made: 1 Using media is very important both to increase the learners’ motivation and to give a big opportunity to learners to explore their idea. 2 Giving more variations techniques in teaching and learning process in order do not monotonous. 3 Giving prizes, encouraging and giving extra points for learners who can express their idea by speaking English well. 4 Creating

  20. Uniform trigonometric polynomial B-spline curves

    Institute of Scientific and Technical Information of China (English)

    吕勇刚; 汪国昭; 杨勋年

    2002-01-01

    This paper presents a new kind of uniform spline curve, named trigonometric polynomialB-splines, over space Ω = span{sint, cost, tk-3,tk-4,…,t,1} of which k is an arbitrary integerlarger than or equal to 3. We show that trigonometric polynomial B-spline curves have many similarV properties to traditional B-splines. Based on the explicit representation of the curve we have also presented the subdivision formulae for this new kind of curve. Since the new spline can include both polynomial curves and trigonometric curves as special cases without rational form, it can be used as an efficient new model for geometric design in the fields of CAD/CAM.

  1. Research on physical shape preserving curve reconstruction

    Institute of Scientific and Technical Information of China (English)

    TANG Kelun; ZHANG Xiangwei; CHENG Siyuan; XIONG Hanwei; ZHANG Hong

    2007-01-01

    Fusion of various data is an effective way to improve the precision and efficiency of acquiring information in reverse engineering.A method of physical shape preserving curve reconstruction is proposed to better realize the data fusion of coordinate measuring machine (CMM) and visual information.From the principle of materials mechanics,the strain energy of the curve corresponding to the distortion is advanced as the internal energy,and the elastic potential energy of the curve is established,using a few precise measured data points as the equilibrium position,to be the external energy.On the basis of the principle of variation calculus,the basic spline finite element method (B-spline FEM) is used to determine the equilibrium position of curve deformation.Numerical simulation indicates that there is an extremely good agreement between the new fitted curve and the actual curve.

  2. Forces in the complex octonion curved space

    CERN Document Server

    Weng, Zi-Hua

    2016-01-01

    The paper aims to extend major equations in the electromagnetic and gravitational theories from the flat space into the complex octonion curved space. Maxwell applied simultaneously the quaternion analysis and vector terminology to describe the electromagnetic theory. It inspires subsequent scholars to study the electromagnetic and gravitational theories with the complex quaternions/octonions. Furthermore Einstein was the first to depict the gravitational theory by means of tensor analysis and curved four-space-time. Nowadays some scholars investigate the electromagnetic and gravitational properties making use of the complex quaternion/octonion curved space. From the orthogonality of two complex quaternions, it is possible to define the covariant derivative of the complex quaternion curved space, describing the gravitational properties in the complex quaternion curved space. Further it is possible to define the covariant derivative of the complex octonion curved space by means of the orthogonality of two comp...

  3. Motivations for Individualization of Punishments

    Directory of Open Access Journals (Sweden)

    Ghobad Naderi

    2013-02-01

    Full Text Available In this research, Motivated by Individualization -defense to penalties, seeks to answers to this question whether principle Individualization penalty, can be recognized as a legal principle? Individualization penalty means: Differentiate between the delinquents and determine the penalty imposed or alternately follows the character of the offender and the punishment that is imposed on him. In this research Western of Jurists the views (of Individualization motivations to penalties have been investigated. Now, to the motivations study of the Individualization we explain penalties.

  4. Beyond Cognition: Reading Motivation and Reading Comprehension

    OpenAIRE

    Wigfield, Allan; Gladstone, Jessica; Turci, Lara

    2016-01-01

    The authors review research on children’s reading motivation and its relation to their reading comprehension. They begin by discussing work on the development of school motivation in general and reading motivation in particular, reviewing work showing that many children’s reading motivation declines over the school years. Girls tend to have more positive motivation for reading than do boys, and there are ethnic differences in children’s reading motivation. Over the last 15 years researchers h...

  5. Motivation factors enabling positive deviance at workplace

    OpenAIRE

    Olasmaa, Tomi

    2010-01-01

    Motivation concerns a person’s willingness to do something. Managers of organizations wish to keep their employees’ motivation level high and improve the performance of the organization. To keep the motivation level high, managers have to acknowledge what are the factors that influence the motivation level of employees. This Bachelor’s Thesis explores factors that influence personnel motivation at workplace. It also studies if these motivational factors enable positive deviance of organizatio...

  6. Motivating employees : Case: Company XXXX Oy

    OpenAIRE

    Heikkilä, Elina

    2012-01-01

    XXXX Oy commissioned this study. The company’s business is watch and jewellery retail trade, import and export. The purpose of the study was to identify current employee motivation level at XXXX Oy. The study provided theoretical information of motivation, research of current employee motivation level and motivation techniques for the commissioning company. The current motivation level was examined according to Frederick Herzberg’s Motivation-Hygiene theory and Victor Vroom’s Expectancy t...

  7. Motivating employees : Case: Company XXXX Oy

    OpenAIRE

    Heikkilä, Elina

    2012-01-01

    XXXX Oy commissioned this study. The company’s business is watch and jewellery retail trade, import and export. The purpose of the study was to identify current employee motivation level at XXXX Oy. The study provided theoretical information of motivation, research of current employee motivation level and motivation techniques for the commissioning company. The current motivation level was examined according to Frederick Herzberg’s Motivation-Hygiene theory and Victor Vroom’s Expectancy t...

  8. Conditionally bounding analytic ranks of elliptic curves

    CERN Document Server

    Bober, Jonathan W

    2011-01-01

    We describe a method for bounding the rank of an elliptic curve under the assumptions of the Birch and Swinnerton-Dyer conjecture and the generalized Riemann hypothesis. As an example, we compute, under these conjectures, exact upper bounds for curves which are known to have rank at least as large as 20, 21, 22, 23, and 24. For the known curve of rank at least 28, we get a bound of 30.

  9. Riemann Boundary Value Problems for Koch Curve

    Directory of Open Access Journals (Sweden)

    Zhengshun Ruanand

    2012-11-01

    Full Text Available In this study, when L is substituted for Koch curve, Riemann boundary value problems was defined, but generally speaking, Cauchy-type integral is meaningless on Koch curve. When some analytic conditions are attached to functions G (z and g (z, through the limit function of a sequence of Cauchytype integrals, the homogeneous and non-homogeneous Riemann boundary problems on Koch curve are introduced, some similar results was attained like the classical boundary value problems for analytic functions.

  10. Skill Acquisition Curves and Military Training

    Science.gov (United States)

    1986-01-01

    group acquisition curves had one of two general shapes, either logarithmic (power function) or semi- logarithmic (exponential), including variants...is, so far as we aware, no inherent advantage to the use of equations in linear or logarithmic form other than that the display of fitted curves in...implications for the expected form of the acquisition curve . As Mazur and Hastie (1978) note, accumulation models yield the hyperbola (a power law

  11. A Local Torelli's Theorem for SUSY curves

    CERN Document Server

    Codogni, Giulio

    2014-01-01

    SUSY curves, or super Riemann surfaces, are the generalization of Riemann surfaces in the context of super geometry. The main goal of this paper is to construct some explicit families of SUSY curves with odd moduli and compute their periods. By comparing our result with its classical analogue, we make an educated guess about the tangent space to the period domain and the differential of the Jacobian morphism for SUSY curves.

  12. Motivation for pilgrimage: using theory to explore motivations

    Directory of Open Access Journals (Sweden)

    Ruth Blackwell

    2010-01-01

    Full Text Available This article is a discussion of the motivations for pilgrimage and it will draw upon theories of motivation to explore the continuing attraction of pilgrimage in contemporary times. This discussion is located within the field of Event Management. Event Management is a fast growing discipline which focuses on the design, production and management of planned events, such as festivals, celebrations, conferences, fund-raisers and so on. Clearly pilgrimages, as planned events, fit into this definition. In this context, it is essential to recognise the importance of understanding the motives and needs of event customers so that we can plan to help our customers satisfy their motives. Whilst it might seem abhorrent and commercial to talk of pilgrims as customers, pilgrimages and religious sites have become more and more commodified and increasingly are deemed to need professional management. Key theories of motivation will be compared in order to identify the prime motivating factors underpinning people’s decisions to make pilgrimages.

  13. Algebraic curves and one-dimensional fields

    CERN Document Server

    Bogomolov, Fedor

    2002-01-01

    Algebraic curves have many special properties that make their study particularly rewarding. As a result, curves provide a natural introduction to algebraic geometry. In this book, the authors also bring out aspects of curves that are unique to them and emphasize connections with algebra. This text covers the essential topics in the geometry of algebraic curves, such as line and vector bundles, the Riemann-Roch Theorem, divisors, coherent sheaves, and zeroth and first cohomology groups. The authors make a point of using concrete examples and explicit methods to ensure that the style is clear an

  14. Orthogonal Polynomials and $S$-curves

    CERN Document Server

    Rakhmanov, E A

    2011-01-01

    This paper is devoted to a study of $S$-curves, that is systems of curves in the complex plane whose equilibrium potential in a harmonic external field satisfies a special symmetry property ($S$-property). Such curves have many applications. In particular, they play a fundamental role in the theory of complex (non-hermitian) orthogonal polynomials. One of the main theorems on zero distribution of such polynomials asserts that the limit zero distribution is presented by an equilibrium measure of an $S$-curve associated with the problem if such a curve exists. These curves are also the starting point of the matrix Riemann-Hilbert approach to srtong asymptotics. Other approaches to the problem of strong asymptotics (differential equations, Riemann surfaces) are also related to $S$-curves or may be interpreted this way. Existence problem $S$-curve in a given class of curves in presence of a nontrivial external field presents certain challenge. We formulate and prove a version of existence theorem for the case whe...

  15. Motivation of Online Buyer Behavior

    National Research Council Canada - National Science Library

    Veronika Svatosová

    2013-01-01

    .... The subject matter of this article is an analysis of the features of online buyer behavior compared to the general regularities of buyer behavior, definition of the main motives of online shopping...

  16. In reality, I motivate myself!

    DEFF Research Database (Denmark)

    Mariager-Anderson, Kristina; Cort, Pia; Thomsen, Rie

    2016-01-01

    ‘Education, education, education’ has been a mantra in transnational and national policies since the mid-1990s: everybody has to take part in learning activities throughout their lives in order to stay employable. Hereby lifelong learning establishes a dividing practice between active and inactiv...... life span. On the basis of the Self-Determination Theory, we argue that low-skilled workers are active and motivated; however, their motivational orientation may not be towards what is considered productive activities....... lifelong learners constituting the latter as a ‘problem’. The EU call is to make people active, with an underlying assumption of people not being motivated. This article explores how one such ‘inactive’ group, low-skilled workers, narrates motivation for learning, work and other activities through a work...

  17. Motivation of Markedness in Antonyms

    Institute of Scientific and Technical Information of China (English)

    曹琪雯

    2014-01-01

    This paper mainly explores the motivation of markedness is explored in three different types of antonyms:graduable antonyms, complementary antonyms and converse antonyms. It holds that markedness is mainly caused by cognitive factors, culture factors and politeness principle.

  18. Individualized approach to staff motivation

    National Research Council Canada - National Science Library

    Elena Shirokova; Anastasiya Kalinichenko

    2016-01-01

    The article reveals the formation of a system of incentives for workers, allowing to identify the impact of the individual needs of the employee and the possibility of rational use of specific tools for labor motivation...

  19. Managing Motivation In Personalized Instruction

    Science.gov (United States)

    Wagner, G. R.; And Others

    1974-01-01

    addresses the topic of managing motivation in Keller's Personalized System of Instruction (PSI). Outlines the reinforcing features that are at the foundation of PSI theory, and examines methods used to ensure that these reinforcing properties are fu lly utilized. (JR)

  20. In reality, I motivate myself!

    DEFF Research Database (Denmark)

    Mariager-Anderson, Kristina; Cort, Pia; Thomsen, Rie

    2016-01-01

    ‘Education, education, education’ has been a mantra in transnational and national policies since the mid-1990s: everybody has to take part in learning activities throughout their lives in order to stay employable. Hereby lifelong learning establishes a dividing practice between active and inactiv...... life span. On the basis of the Self-Determination Theory, we argue that low-skilled workers are active and motivated; however, their motivational orientation may not be towards what is considered productive activities....... lifelong learners constituting the latter as a ‘problem’. The EU call is to make people active, with an underlying assumption of people not being motivated. This article explores how one such ‘inactive’ group, low-skilled workers, narrates motivation for learning, work and other activities through a work...

  1. MLE's bias pathology motivates MCMLE

    OpenAIRE

    Yatracos, Yannis G.

    2013-01-01

    Maximum likelihood estimates are often biased. It is shown that this pathology is inherent to the traditional ML estimation method for two or more parameters, thus motivating from a different angle the use of MCMLE.

  2. [Satisfaction and motivation in nursing].

    Science.gov (United States)

    Antunes, A V; Sant Anna, L R

    1996-01-01

    Something which affects the internal balance of a hospital system is its workers satisfaction/motivation rate. According to observed and discussed facts regarding our professional environment and also according to some authors assessments (Alcântara and Ribas Gomes), it seems that there is an insatisfaction among those people in relation to their chores. Therefore, based on Herzberg et all. two factors theory and more specifically on Maximiano interpretation of that theory, we made a research aiming at verifying the satisfaction and motivation in nurse work; on how satisfied/insatisfied nurses feel in their work, and if there is a relationship between job conditions (hygienic factors) with satisfaction, and between job features (motivation factors) with motivation.

  3. Motivation and Second Language Acquisition

    Directory of Open Access Journals (Sweden)

    Steve Buckledee

    2008-06-01

    Full Text Available A feature of Italian universities is the high student drop-out rate in nearly all degree courses. It is likely that among the causes of this phenomenon a significant factor is loss of motivation. This study represents the first stage of a longitudinal research project aimed at monitoring students’ motivation levels over a three-year period. At the beginning of the academic year 2008-2009 a questionnaire was administered to 150 newly enrolled students of English at the University of Cagliari in Italy. The closed-response items were designed to measure the respondents’ instrumental and intrinsic motivation. The responses were then considered in the light of the following variables: age, gender, level of competence in English and choice of degree course. The major finding was that a clear majority of respondents reported a considerably higher level of intrinsic than instrumental motivation, while the most significant variables were shown to be competence level and choice of degree.

  4. Intrinsic motivation and learning dynamics

    CERN Document Server

    Zgonnikov, Arkady

    2013-01-01

    We investigate the effects of intrinsic motivation on the dynamics of learning processes. We construct a simple model of a single agent adapting to unknown environment. Performing a repeated choice between a number of initially unexplored alternatives, the agent gains rewards for each selected alternative and in doing so gradually comprehends the environment. In our model the agent choice is governed by two stimuli. The traditional extrinsic motive inclines the agent to maximize the cumulative payoff throughout the process, while the second, intrinsic one, biases the agent towards the novel options that she inherently likes. We show that the intrinsic motivation can induce an instability and periodic dynamics of the learning process which is always stationary in the case of selfish, rational agent. Interestingly, the opposite effect can arise as well: when the impact of intrinsic motivation on the agent choice is strong, the equiprobable choice equilibrium strategy becomes stable. Based on the presented resul...

  5. Motivational Rehabilitation using Serious Games

    OpenAIRE

    Antoni Jaume i Capó; Javier Varona Gómez; Gabriel Moyà; Francisco Perales

    2013-01-01

    Research studies show that serious games help to motivate users in rehabilitation processes, and rehabilitation results are better when users are motivated. In long term rehabilitation for maintaining capacities, the demotivation of chronic patients is common. In this work, we have implemented balance rehabilitation video game for cerebral palsy patients. The video game was developed using the prototype development paradigm and following desirable features for rehabilitation serious games pre...

  6. Weight structure on noncommutative motives

    CERN Document Server

    Tabuada, Goncalo

    2011-01-01

    In this note we endow Kontsevich's category KMM of noncommutative mixed motives with a non-degenerate weight structure in the sense of Bondarko. As an application we obtain a convergent weight spectral sequence for every additive invariant (e.g. algebraic K-theory, cyclic homology, topological Hochschild homology, etc.), and a ring isomorphism between the Grothendieck ring of KMM and the Grothendieck ring of the category of noncommutative Chow motives.

  7. Drinking Motives and Links to Alcohol Use in 13 European Countries

    NARCIS (Netherlands)

    Kuntsche, E.N.; Gabhainn, S.N.; Roberts, C.; Windlin, B.; Vieno, A.; Bendtsen, P.; Hublet, A.; Tynjala, J.; Valimaa, R.; Dankulincova, Z.; Aasvee, K.; Demetrovics, Z.; Farkas, J.; Sluijs, W. van der; Gaspar de Matos, M.; Mazur, J.; Wicki, M.

    2014-01-01

    Objective: The purpose of this study was to test the structure and endorsement of drinking motives and their links to alcohol use among 11- to 19-year-olds from 13 European countries. Method: Confirmatory factor analysis, latent growth curves, and multiple regression models were conducted, based on

  8. The Impact of the Combination of Circular Curve and Transition Curve on Highway Operation Security

    Directory of Open Access Journals (Sweden)

    Cao Youlu

    2015-07-01

    Full Text Available By investigating the accident in 2009 and 2011 of Taijiu Expressway, the study analyzed the relationship between the horizontal curve radiuses, the length of horizontal curve, the length of transition curve and the number of accidents, established the corresponding regression model. The trend of accidents was determined with different length of transition curve and different combination of circular curve according to this model. The results show that the circular curve radius and length of transition curve increase with the decreases of accidents number, the number of accidents decreases with the increase of the ratio of the length of the transition curve and the length of the round curve. When the ratio of the parameters of the transition curve and the radius of the circle is between 0.3-0.6, the accidents are more focused. The bigger change rate of curves is, there are more accidents of flat curve. To evaluate road traffic safety from the perspective of horizontal curve alignment design, these regularities have very important reference.

  9. Learning curves in energy planning models

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, L.; Kypreos, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    This study describes the endogenous representation of investment cost learning curves into the MARKAL energy planning model. A piece-wise representation of the learning curves is implemented using Mixed Integer Programming. The approach is briefly described and some results are presented. (author) 3 figs., 5 refs.

  10. Curve Matching with Applications in Medical Imaging

    DEFF Research Database (Denmark)

    Bauer, Martin; Bruveris, Martins; Harms, Philipp

    2015-01-01

    In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several...

  11. Rotation curve of the Milky Way

    Directory of Open Access Journals (Sweden)

    Lee Y.S.

    2012-02-01

    Full Text Available We use SEGUE and Hipparcos data to restrict the behaviour of the rotation curve of the Milky Way in the solar neighbourhood. Then we construct a density model of the Milky Way which best reproduces the available observations of the rotation curve and is consistent with the density constraints in the solar neighbourhood.

  12. Spectral Curves of Operators with Elliptic Coefficients

    Directory of Open Access Journals (Sweden)

    J. Chris Eilbeck

    2007-03-01

    Full Text Available A computer-algebra aided method is carried out, for determining geometric objects associated to differential operators that satisfy the elliptic ansatz. This results in examples of Lamé curves with double reduction and in the explicit reduction of the theta function of a Halphen curve.

  13. Tautological Integrals on Symmetric Products of Curves

    Institute of Scientific and Technical Information of China (English)

    Zhi Lan WANG

    2016-01-01

    We propose a conjecture on the generating series of Chern numbers of tautological bundles on symmetric products of curves and establish the rank 1 and rank −1 case of this conjecture. Thus we compute explicitly the generating series of integrals of Segre classes of tautological bundles of line bundles on curves, which has a similar structure as Lehn’s conjecture for surfaces.

  14. Green's Conjecture for the generic canonical curve

    OpenAIRE

    Teixidor-I-Bigas, Montserrat

    1998-01-01

    Green's Conjecture states the following : syzygies of the canonical model of a curve are simple up to the p^th stage if and only if the Clifford index of C is greater than p. We prove that the generic curve of genus g satisfies Green's conjecture.

  15. Blending Canal Surfaces Based on PH Curves

    Institute of Scientific and Technical Information of China (English)

    Chen-Dong Xu; Fa-Lai Chen

    2005-01-01

    In this paper, a new method for blending two canal surfaces is proposed. The blending surface is itself a generalized canal surface, the spine curve of which is a PH (Pythagorean-Hodograph) curve. The blending surface possesses an attractive property - its representation is rational. The method is extensible to blend general surfaces as long as the blending boundaries are well-defined.

  16. The density curve of F distribution

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaopeng; LIU Kunhui

    2004-01-01

    Employing the properties of special function,we discuss the positional relation between two density curves with different parameters for F distribution in this paper.Some varying regularities about the position of density curve of F distribution have been obtained.

  17. Electrical-Discharge Machining Of Curved Passages

    Science.gov (United States)

    Guirguis, Kamal S.

    1993-01-01

    Electrical-discharge machining (EDM) used to cut deep hole with bends. EDM process done with articulating segmented electrode. Originally straight, electrode curved as it penetrates part, forming long, smoothly curving hole. After hole cut, honed with slurry to remove thin layer of recast metal created by EDM. Breakage of tools, hand deburring, and drilling debris eliminated.

  18. Integrability and the motion of curves

    Science.gov (United States)

    Nakayama, Kazuaki; Segur, Harvey; Wadati, Miki

    1992-11-01

    Recently discovered connections between integrable evolution equations and the motion of curves are based on the following fact: The Serret-Frenet equations are equivalent to the Ablowitz-Kaup-Newell-Segur (AKNS) scattering problem at zero eigenvalue. This equivalence identifies those evolution equations, integrable or not, that can describe the motion of curves.

  19. Constructing forward price curves in electricity markets

    DEFF Research Database (Denmark)

    Fleten, S.-E.; Lemming, Jørgen Kjærgaard

    2003-01-01

    We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available...

  20. 47 CFR 80.767 - Propagation curve.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Propagation curve. 80.767 Section 80.767... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.767 Propagation curve. The propagation graph, § 80.767 Graph 1, must be used in computing the service area contour. The graph...

  1. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  2. Modeling Start Curves of Bainite Formation

    NARCIS (Netherlands)

    Van Bohemen, S.M.C.

    2009-01-01

    It is demonstrated that calculations with a physically based model give an accurate description of the start curve of bainite formation in a wide range of steels. The temperature dependence of the overall kinetics, which determines the characteristic C shape of the start curve, is controlled by both

  3. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  4. Predicting long-term growth in students' mathematics achievement: the unique contributions of motivation and cognitive strategies.

    Science.gov (United States)

    Murayama, Kou; Pekrun, Reinhard; Lichtenfeld, Stephanie; Vom Hofe, Rudolf

    2013-01-01

    This research examined how motivation (perceived control, intrinsic motivation, and extrinsic motivation), cognitive learning strategies (deep and surface strategies), and intelligence jointly predict long-term growth in students' mathematics achievement over 5 years. Using longitudinal data from six annual waves (Grades 5 through 10; Mage  = 11.7 years at baseline; N = 3,530), latent growth curve modeling was employed to analyze growth in achievement. Results showed that the initial level of achievement was strongly related to intelligence, with motivation and cognitive strategies explaining additional variance. In contrast, intelligence had no relation with the growth of achievement over years, whereas motivation and learning strategies were predictors of growth. These findings highlight the importance of motivation and learning strategies in facilitating adolescents' development of mathematical competencies.

  5. Estimates for J-curves as submanifolds

    CERN Document Server

    Fish, Joel W

    2009-01-01

    Here we develop some basic analytic tools to study compactness properties of $J$-curves (i.e. pseudo-holomorphic curves) when regarded as submanifolds. Incorporating techniques from the theory of minimal surfaces, we derive an inhomogeneous mean curvature equation for such curves, we establish an extrinsic monotonicity principle for non-negative functions $f$ satisfying $\\Delta f\\geq -c^2 f$, we show that curves locally parameterized as a graph over a coordinate tangent plane have all derivatives a priori bounded in terms of curvature and ambient geometry, and we establish $\\epsilon$-regularity for the square length of their second fundamental forms. These results are all provided for $J$-curves either with or without Lagrangian boundary and hold in almost Hermitian manifolds of arbitrary even dimension (i.e. Riemannian manifolds for which the almost complex structure is an isometry).

  6. STATIONARY CONNECTED CURVES IN HILBERT SPACES

    Directory of Open Access Journals (Sweden)

    Raed Hatamleh

    2014-01-01

    Full Text Available In this article the structure of non-stationary curves which are stationary connected in Hilbert space is studied using triangular models of non-self-adjoint operator. The concept of evolutionary representability plays here an important role. It is proved that if one of two curves in Hilbert space is evolutionary representable and the curves are stationary connected, then another curve is evolutionary representable too. These curves are studied firstly. The structure of a cross-correlation function in the case when operator, defining the evolutionary representation, has one-dimensional non-Hermitian subspace (the spectrum is discreet and situated in the upper complex half-plane or has infinite multiplicity at zero (Volterra operator is studied.

  7. Generating artificial light curves: Revisited and updated

    CERN Document Server

    Emmanoulopoulos, D; Papadakis, I E

    2013-01-01

    The production of artificial light curves with known statistical and variability properties is of great importance in astrophysics. Consolidating the confidence levels during cross-correlation studies, understanding the artefacts induced by sampling irregularities, establishing detection limits for future observatories are just some of the applications of simulated data sets. Currently, the widely used methodology of amplitude and phase randomisation is able to produce artificial light curves which have a given underlying power spectral density (PSD) but which are strictly Gaussian distributed. This restriction is a significant limitation, since the majority of the light curves e.g. active galactic nuclei, X-ray binaries, gamma-ray bursts show strong deviations from Gaussianity exhibiting `burst-like' events in their light curves yielding long-tailed probability distribution functions (PDFs). In this study we propose a simple method which is able to precisely reproduce light curves which match both the PSD an...

  8. Remote sensing used for power curves

    Science.gov (United States)

    Wagner, R.; Jørgensen, H. E.; Paulsen, U. S.; Larsen, T. J.; Antoniou, I.; Thesbjerg, L.

    2008-05-01

    : Power curve measurement for large wind turbines requires taking into account more parameters than only the wind speed at hub height. Based on results from aerodynamic simulations, an equivalent wind speed taking the wind shear into account was defined and found to reduce the power standard deviation in the power curve significantly. Two LiDARs and a SoDAR are used to measure the wind profile in front of a wind turbine. These profiles are used to calculate the equivalent wind speed. The comparison of the power curves obtained with the three instruments to the traditional power curve, obtained using a cup anemometer measurement, confirms the results obtained from the simulations. Using LiDAR profiles reduces the error in power curve measurement, when these are used as relative instrument together with a cup anemometer. Results from the SoDAR do not show such promising results, probably because of noisy measurements resulting in distorted profiles.

  9. Curved and conformal high-pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, Paul F.; Kuczek, Andrzej E.; Zhao, Wenping

    2016-10-25

    A high-pressure vessel is provided. The high-pressure vessel may comprise a first chamber defined at least partially by a first wall, and a second chamber defined at least partially by the first wall. The first chamber and the second chamber may form a curved contour of the high-pressure vessel. A modular tank assembly is also provided, and may comprise a first mid tube having a convex geometry. The first mid tube may be defined by a first inner wall, a curved wall extending from the first inner wall, and a second inner wall extending from the curved wall. The first inner wall may be disposed at an angle relative to the second inner wall. The first mid tube may further be defined by a short curved wall opposite the curved wall and extending from the second inner wall to the first inner wall.

  10. AHT Bézier Curves and NUAHT B-Spline Curves

    Institute of Scientific and Technical Information of China (English)

    Gang Xu; Guo-Zhao Wang

    2007-01-01

    In this paper, we present two new unified mathematics models of conics and polynomial curves, called algebraic hyperbolic trigonometric ( AHT) Bézier curves and non-uniform algebraic hyperbolic trigonometric ( NUAHT) B-sptine curves of order n, which are generated over the space span{sin t, cos t, sinh t, cosh t, 1, t,..., tn-5}, n ≥ 5. The two kinds of curves share most of the properties as those of the Bézier curves and B-spline curves in polynomial space. In particular, they can represent exactly some remarkable transcendental curves such as the helix, the cycloid and the catenary. The subdivision formulae of these new kinds of curves are also given. The generations of the tensor product surfaces are straightforward. Using the new mathematics models, we present the control mesh representations of two classes of minimal surfaces.

  11. Motivational Spiral Models (MSM): common and distinct motivations in context.

    Science.gov (United States)

    Fisher, Laurel J

    2013-01-01

    Motivational Spiral Models (MSM) show links over time among self concepts, feelings, strategies, skills and participation in everyday activities. In theory, MSM have many common features, with distinct features in particular contexts. This project examined children's motivation to participate in literacy (MSM-L), social (MSM-S) and physical activities (MSM-P). The participants in Study 1 (N = 32) were 9 to 11 years old, and in Study 2 (N = 73) were 4 to 12 year old children. Locations were close to the Australian national average in socio-economic indicators, and initial screening showed these were representative samples. Analyses used variable-oriented correlational models as well as person-oriented clusters that suggest the standard and alternative motivational pathways. The results of Study 1 suggested bi-directional links between children's self concepts and participation in activities. Study 2 identified the common features as: openness and stability over time; and self concepts that motivate and justify participation in activities. Distinct features of MSM-L show the few negative feelings that may limit reading. In MSM-S, self concepts support the positive feelings, and in MSM-P, positive feelings support the task strategies. In conclusion, findings support MSM theory with common features based on self concepts and distinct features of developing motivations in particular contexts. MSM provide a sound base for future research in the contexts of everyday activities for children. In addition, there are practical applications of the findings to prevention, monitoring and intervention programmes.

  12. Unifying representation of Bézier curve and two kinds of generalized ball curves

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiaolin; WANG Zhihua

    2012-01-01

    This paper presents a new basis, the WSB basis, which unifies the Bemstein basis, Wang-Ball basis and Said-Ball basis, and therefore the Bézier curve, Wang-Ball curve and Said-Ball curve are the special cases of the WSB curve based on the WSB basis In addition, the relative degree elevation formula, recursive algorithm and conversion formula between the WSB basis and the Bern- stein basis are given.

  13. Spitzer IRAC Sparsely Sampled Phase Curve of the Exoplanet WASP-14b

    CERN Document Server

    Krick, J E; Carey, S; von Braun, K; Kane, S R; Ciardi, D; Plavchan, P; Wong, I; Lowrance, P

    2016-01-01

    Motivated by a high Spitzer IRAC oversubscription rate, we present a new technique of randomly and sparsely sampling phase curves of hot Jupiters. Snapshot phase curves are enabled by technical advances in precision pointing as well as careful characterization of a portion of the central pixel on the array. This method allows for observations which are a factor of roughly two more efficient than full phase curve observations, and are furthermore easier to insert into the Spitzer observing schedule. We present our pilot study from this program using the exoplanet WASP-14b. Data of this system were taken both as a sparsely sampled phase curve as well as a staring mode phase curve. Both datasets as well as snapshot style observations of a calibration star are used to validate this technique. By fitting our WASP-14b phase snapshot dataset, we successfully recover physical parameters for the transit and eclipse depths as well as amplitude and maximum and minimum of the phase curve shape of this slightly eccentric ...

  14. Shape selection of surface-bound helical filaments: biopolymers on curved membranes

    CERN Document Server

    Quint, D A; Grason, G M

    2016-01-01

    Motivated to understand the behavior of biological filaments interacting with membranes of various types, we study a theoretical model for the shape and thermodynamics of intrinsically-helical filaments bound to curved membranes. We show filament-surface interactions lead to a host of non-uniform shape equilibria, in which filaments progressively unwind from their native twist with increasing surface interaction and surface curvature, ultimately adopting uniform-contact curved shapes. The latter effect is due to non-linear coupling between elastic twist and bending of filaments on anisotropically-curved surfaces, such as the cylindrical surfaces considered here. Via a combination of numerical solutions and asymptotic analysis of shape equilibria we show that filament conformations are critically sensitive to the surface curvature in both the strong- and weak-binding limits. These results suggest that local structure of membrane-bound chiral filaments is generically sensitive to the curvature-radius of the sur...

  15. Circadian Insights into Motivated Behavior.

    Science.gov (United States)

    Antle, Michael C; Silver, Rae

    2016-01-01

    For an organism to be successful in an evolutionary sense, it and its offspring must survive. Such survival depends on satisfying a number of needs that are driven by motivated behaviors, such as eating, sleeping, and mating. An individual can usually only pursue one motivated behavior at a time. The circadian system provides temporal structure to the organism's 24 hour day, partitioning specific behaviors to particular times of the day. The circadian system also allows anticipation of opportunities to engage in motivated behaviors that occur at predictable times of the day. Such anticipation enhances fitness by ensuring that the organism is physiologically ready to make use of a time-limited resource as soon as it becomes available. This could include activation of the sympathetic nervous system to transition from sleep to wake, or to engage in mating, or to activate of the parasympathetic nervous system to facilitate transitions to sleep, or to prepare the body to digest a meal. In addition to enabling temporal partitioning of motivated behaviors, the circadian system may also regulate the amplitude of the drive state motivating the behavior. For example, the circadian clock modulates not only when it is time to eat, but also how hungry we are. In this chapter we explore the physiology of our circadian clock and its involvement in a number of motivated behaviors such as sleeping, eating, exercise, sexual behavior, and maternal behavior. We also examine ways in which dysfunction of circadian timing can contribute to disease states, particularly in psychiatric conditions that include adherent motivational states.

  16. Motivational Strategies in Medical English Classroom

    Institute of Scientific and Technical Information of China (English)

    TIAN Jun-ying

    2014-01-01

    Objective:To explore strategies to motivate students in the classroom of Medical English. Methods:The motivational strategies applied in medical English classroom including defining course goals early in the semester, appropriate teacher behavior, creating real context and giving helpful and frequent Feedback were recommended. Results & Conclusion: The motivational strategies make a positive impact on students’motivation in medical English classroom.

  17. Academic Motivation: Concepts, Strategies, and Counseling Approaches

    Science.gov (United States)

    Rowell, Lonnie; Hong, Eunsook

    2013-01-01

    Motivation is an important foundation of academic development in students. This article discusses academic motivation; its various component concepts in areas such as beliefs, goals, and values; and intrinsic and extrinsic motivation. It also presents major, widely studied theoretical perspectives of academic motivation and briefly illustrates…

  18. Study on Motivation of Chinese College Students

    Institute of Scientific and Technical Information of China (English)

    许楚娟

    2014-01-01

    This paper aims to investigate the motivation of Chinese college students. Questionnaires and other means of statistics are adopted to analyze college students’motivation and their motivating degree. The author also lists out some advices for the college English teachers to improve their teaching method and protect the students ’learning motivation.

  19. Researching Motivation in Context: Rethinking Methodologies.

    Science.gov (United States)

    Beltman, Susan

    Recent theory and research on motivation has shifted in its focus from a study of more general characteristics of individuals such as personal motivational goals, to an examination of the motivation of individuals within specific domains or contexts. This change in focus has led to a broadening of the methodologies used to examine motivation. Many…

  20. A General Overview of Motivation in Linguistics

    Institute of Scientific and Technical Information of China (English)

    王航

    2014-01-01

    In recent years, the term of motivation in linguistics study has aroused the interests of scholars. Different studies of mo -tivation have been produced by different scholars. In this paper, the writer organizes the recent studies on motivation in linguistics. the paper is divided into three parts, the introduction of the term motivation, different types of motivation, and theories of moti -vation.

  1. The Measurement of Motivation with Science Students

    Science.gov (United States)

    Mubeen, Sarwat; Reid, Norman

    2014-01-01

    Motivation is an inner force that activates and provides direction to our thought, feelings and actions. Two main characteristics of motivation are goal directed behavior and persistence. Motivated people persistently work for the goal until it is achieved. This paper explores the nature of motivation in the context of learning and seeks to relate…

  2. Enhancing Motivation for Learning and Work.

    Science.gov (United States)

    Kirkhorn, Judith

    1988-01-01

    Discusses motivation based on adult learning conditions, and suggests appropriate motivation plans for leaders and trainers that will enhance performance. The steps to develop motivation plans include assessing current thinking on motivation and reinforcement options; objectively describing expected behaviors; and developing motivational…

  3. Academic Motivation: Concepts, Strategies, and Counseling Approaches

    Science.gov (United States)

    Rowell, Lonnie; Hong, Eunsook

    2013-01-01

    Motivation is an important foundation of academic development in students. This article discusses academic motivation; its various component concepts in areas such as beliefs, goals, and values; and intrinsic and extrinsic motivation. It also presents major, widely studied theoretical perspectives of academic motivation and briefly illustrates…

  4. Three-body choreographies in given curves

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Hiroshi [General Education Program Center, Tokai University, 317 Nishino, Numazu, Shizuoka 410-0395 (Japan); Fukuda, Hiroshi; Fujiwara, Toshiaki [College of Liberal Arts and Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555 (Japan)], E-mail: ozaki@keyaki.cc.u-tokai.ac.jp, E-mail: fukuda@kitasato-u.ac.jp, E-mail: fujiwara@kitasato-u.ac.jp

    2009-10-02

    As shown by Johannes Kepler in 1609, in the two-body problem, the shape of the orbit, a given ellipse, and a given non-vanishing constant angular momentum determine the motion of the planet completely. Even in the three-body problem, in some cases, the shape of the orbit, conservation of the center of mass and a constant of motion (the angular momentum or the total energy) determine the motion of the three bodies. We show, by a geometrical method, that choreographic motions, in which equal mass three bodies chase each other around the same curve, will be uniquely determined for the following two cases. (i) Convex curves that have point symmetry and non-vanishing angular momentum are given. (ii) Eight-shaped curves which are similar to the curve for the figure-eight solution and the energy constant are given. The reality of the motion should be tested whether the motion satisfies an equation of motion or not. Extensions of the method for generic curves are shown. The extended methods are applicable to generic curves which do not have point symmetry. Each body may have its own curve and its own non-vanishing masses.

  5. Investigation of learning and experience curves

    Energy Technology Data Exchange (ETDEWEB)

    Krawiec, F.; Thornton, J.; Edesess, M.

    1980-04-01

    The applicability of learning and experience curves for predicting future costs of solar technologies is assessed, and the major test case is the production economics of heliostats. Alternative methods for estimating cost reductions in systems manufacture are discussed, and procedures for using learning and experience curves to predict costs are outlined. Because adequate production data often do not exist, production histories of analogous products/processes are analyzed and learning and aggregated cost curves for these surrogates estimated. If the surrogate learning curves apply, they can be used to estimate solar technology costs. The steps involved in generating these cost estimates are given. Second-generation glass-steel and inflated-bubble heliostat design concepts, developed by MDAC and GE, respectively, are described; a costing scenario for 25,000 units/yr is detailed; surrogates for cost analysis are chosen; learning and aggregate cost curves are estimated; and aggregate cost curves for the GE and MDAC designs are estimated. However, an approach that combines a neoclassical production function with a learning-by-doing hypothesis is needed to yield a cost relation compatible with the historical learning curve and the traditional cost function of economic theory.

  6. Motivational profile quality players handball

    Directory of Open Access Journals (Sweden)

    Alfonso Martínez Moreno

    2017-06-01

    Full Text Available In the sport context, elite category, it is necessary to know all the factors, which in one way or another, affect the athletes throughout the different competitions. The object of study is to know the motivational profile of elite handball players. The sample consisted of 495 players, of whom 47.8% were boys and 52.2% girls, their ages ranged from 12 to 16 years, with an average of 13.8 years (dt = 1.0. Descriptive statistical analyzes of the sample, absolute and relative frequencies were performed for the qualitative variables and for the quantitative values minimum, maximum, mean, standard deviation, Cronbach's alpha. Correlation between variables, with the Pearson correlation coefficient. The MANCOVA test was performed to determine if there were differences between the dimensions of the questionnaire, according to age and years of practice. The results reveal that handball players elite category of the sample object of study have mainly intrinsic motivation, achieving high scores on general motivation, motivation achievement and motivation stimulation. In addition to moderately high values in introjected regulation and very low values in demotivation.

  7. Motivational condition in educational evaluation

    Directory of Open Access Journals (Sweden)

    Julio Fernando Acosta Muñoz

    2012-01-01

    Full Text Available This is a reflection article, methodologically based on research into and theoretical and conceptual review of the motivational condition in educational evaluation. At the same time, some inquiries about the motivational problems in this education process are made. The objective is to examine what the motivational condition within the process ofeducational evaluation is. On the one hand, educational evaluation is a tool that attests to the knowledge, on the other hand, however, it prevents students from strengthening their interest both in the participation in the specific testing activity and in their learning, since it lays emphasis on extrinsic factors, such as grade, which make students lose and distort their intrinsic motivation to learn. Therefore, the evaluation proposal arisen from the construct of motivation is thought to generate in students positive sensations standing even after goals are obtained. Likewise, it must promote liveliness, integration and psychological health, in order to get students to fulfill their needs and obtain psychological welfare in the classroom.

  8. Job assignments, intrinsic motivation and explicit incentives

    OpenAIRE

    Nafziger, Julia

    2008-01-01

    This paper considers the interplay of job assignments with the intrinsic and extrinsic motivation of an agent. Job assignments influence the self confidence of the agent, and thereby his intrinsic motivation. Monetary reward allow the principal to complement intrinsic motivation with extrinsic incentives. The main result is that the principal chooses an inefficient job assignment rule to enhance the agent's intrinsic motivation even though she can motivate him with monetary rewards. This show...

  9. Motivational Leadership: Tips From the Business World.

    Science.gov (United States)

    Rajiah, Prabhakar; Bhargava, Puneet

    2016-05-01

    It is an important task for leadership to identify the motivating factors for employees and motivate them to fulfill their individual and organizational goals. Although there are several motivational factors (extrinsic and intrinsic), intrinsic motivational factors such as autonomy, mastery, and purpose are more important for deeper lasting job satisfaction and higher performance. In this article, the authors discuss how an understanding of these factors that influence motivation has the potential to transform an organization.

  10. Supersonic Flutter of Laminated Curved Panels

    Directory of Open Access Journals (Sweden)

    M. Ganapathi

    1995-04-01

    Full Text Available Supersonic flutter analysis of laminated composite curved panels is investigated using doubly-curved, quadrilateral, shear flexible, shell element based on field-consistency approach. The formulation includes transverse shear deformation, in-plane and rotary inertias. The aerodynamic force is evaluated using two-dimensional static aerodynamic approximation for high supersonic flow. Initially, the model developed here is verified for the flutter analysis of flat plates. Numerical results are presented for isotropic, orthotropic and laminated anisotropic curved panels. A detailed parametric study is carried out to observe the effects of aspect and thickness ratios, number of layers, lamination scheme, and boundary conditions on flutter boundary.

  11. Mapping curved spacetimes into Dirac spinors

    CERN Document Server

    Sabín, Carlos

    2016-01-01

    We show how to transform a Dirac equation in curved spacetime into a Dirac equation in flat spacetime. In particular, we show that any solution of the free massless Dirac equation in a 1+1 dimensional flat spacetime can be transformed via a local phase transformation into a solution of the corresponding Dirac equation in a curved background, where the spacetime metric is encoded into the phase. In this way, the existing quantum simulators of the Dirac equation can naturally incorporate curved spacetimes. As a first example we use our technique to obtain solutions of the Dirac equation in a particular family of interesting spacetimes in 1+1 dimensions.

  12. Magnetization curve modelling of soft magnetic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Meszaros, I, E-mail: meszaros@eik.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, Bertalan L. street 7., Budapest, H-1111 (Hungary)

    2011-01-01

    In this paper we present an application of the so called hyperbolic model of magnetization. The model was modified and it was applied for nine different soft magnetic alloys. The tested samples were electro-technical steels (FeSi alloys) and a permalloy (FeNi alloy) with strongly different magnetic properties. Among them there are top, medium and definitely poor quality soft magnetic materials as well. Their minor hysteresis loops and normal magnetization curves were measured by alternating current measurement. The hyperbolic model of magnetization was applied for the experimental normal magnetization curves. It was proved that the applied model is excellent for describing mathematically the experimental magnetization curves.

  13. CRC standard curves and surfaces with Mathematica

    CERN Document Server

    von Seggern, David H

    2006-01-01

    Since the publication of the first edition, Mathematica® has matured considerably and the computing power of desktop computers has increased greatly. This enables the presentation of more complex curves and surfaces as well as the efficient computation of formerly prohibitive graphical plots. Incorporating both of these aspects, CRC Standard Curves and Surfaces with Mathematica®, Second Edition is a virtual encyclopedia of curves and functions that depicts nearly all of the standard mathematical functions rendered using Mathematica. While the easy-to-use format remains unchanged from the previ

  14. Inspiring Student Self-Motivation

    Directory of Open Access Journals (Sweden)

    Virginia Brackett

    2007-01-01

    Full Text Available While normally appreciative of the invitation to join colleagues in a discussion of pedagogy and what “works” in the classroom, I have in most instances reluctantly participated in discussion of student motivation. I dip my toe into this philosophical quagmire only if permitted license to substitute the phrase student inspiration in place of student motivation. I also find it helpful to turn the rhetorical tables, as it were, and consider self-motivation on the part of students. The concept of individuals who hold some sense of self that a classroom mentor may nurture through student inspiration is one in which I place a modicum of trust. To “inspire” is literally to “breathe in,” to actively pull sustenance from a proffered external source. Active student determination based on some sense of self may couple with instructor inspiration to promote academic success.

  15. Motivational Rehabilitation using Serious Games

    Directory of Open Access Journals (Sweden)

    Antoni Jaume i Capó

    2013-11-01

    Full Text Available Research studies show that serious games help to motivate users in rehabilitation processes, and rehabilitation results are better when users are motivated. In long term rehabilitation for maintaining capacities, the demotivation of chronic patients is common. In this work, we have implemented balance rehabilitation video game for cerebral palsy patients. The video game was developed using the prototype development paradigm and following desirable features for rehabilitation serious games presented in the literature. We have tested the video game with a set of users who abandoned therapy due to demotivation in the previous year. Results show that the set of users improved their balance and motivation.

  16. Motivational Interviewing by School Nurses

    DEFF Research Database (Denmark)

    Bonde, Ane; Bentsen, Peter; Hindhede, Anette Lykke

    , and practitioners of school health services. Implications :Motivational interviewing spirit and techniques seem to be adaptable and useful for school nurses in counselling children and parents. However, further research and development should address the issues of adjusting the method to counselling families......Title: Motivational Interviewing by School Nurses: Spirit, Techniques, and Dilemmas in the Prevention of Child Obesity Introduction : School nurses play a central role in school-based, preventive health services in Denmark (National Board of Health, 2011), and they may play an important role...... behaviours related to lifestyle diseases in adults (Rubak et al. 2005; Söderlund et al. 2011). The use of motivational interviewing by school nurses for the prevention of child obesity in a family intervention is still new, and evidence on the potentials and problems is scarce (Resnicow, Davis and Rollnick...

  17. Public Service Motivation and Paternalism

    DEFF Research Database (Denmark)

    Holm Pedersen, Lene; Qvistgaard, Lars

    holds a potential to improve public service provision (Belle, 2013, Andersen et al., 2014), it also has dark sides (Van Loon et al., 2015, forthcoming). The aim of this paper is to analyze and discuss how one type of public service motivated individuals (paternalistic knights) and constitute a problem...... of democratic accountability. The setting of this discussion is unusual for the PSM literature, and takes PSM into the analysis and discussion of motivation and paternalism in trade unions. This setting is relevant and interesting as the election of representatives is based on elections, and hence trade unions...... are democratic organizations, but they are also organizations which frequently are critiqued for paternalism. More specifically the research question is how the motivation of the elected representatives is associated to their paternalistic orientation in negotiations on performance pay? The central independent...

  18. Longitudinal analysis of intrinsic motivation and competence beliefs: is there a relation over time?

    Science.gov (United States)

    Spinath, Birgit; Steinmayr, Ricarda

    2008-01-01

    The present study explored whether competence beliefs and intrinsic motivation for different school domains show reciprocal effects over time. A sample of 670 German elementary school pupils (M= 8.8 years, SD= 0.51) was followed over 1 year. At 4 measurement occasions, children completed self-reports on their intrinsic motivation and competence beliefs for math, German, and school in general. Latent growth models revealed that intrinsic motivation and competence beliefs decreased over time. Comparing correlational and cross-lagged structural equation models yielded only weak evidence for cross-lagged influences between the 2 constructs. Results suggest that the developmental curves of competence beliefs and intrinsic motivation might be less inextricably interwoven than frequently assumed.

  19. Drinking motives and links to alcohol use in 13 European countries

    DEFF Research Database (Denmark)

    Kuntsche, Emmanuel; Gabhainn, Saoirse Nic; Roberts, Chris

    2014-01-01

    ABSTRACT. Objective: The purpose of this study was to test the structure and endorsement of drinking motives and their links to alcohol use among 11- to 19-year-olds from 13 European countries. Method: Confirmatory factor analysis, latent growth curves, and multiple regression models were conducted......, based on a sample of 33,813 alcohol-using students from Belgium, Denmark, Estonia, Finland, Hungary, Ireland, Italy, Poland, Portugal, Scotland, Slovakia, Switzerland, and Wales who completed the Drinking Motives Questionnaire Revised Short Form (DMQ-R SF). Results: The findings confirmed...... the hypothesized fourdimensional factor structure. Social motives for drinking were most frequently indicated, followed by enhancement, coping, and conformity motives, in that order, in all age groups in all countries except Finland. This rank order was clearest among older adolescents and those from northern...

  20. Commodity Team Motivation and Performance

    DEFF Research Database (Denmark)

    Englyst, Linda; Jørgensen, Frances; Johansen, John

    2008-01-01

    In this article, an in-depth single case study is presented in order to explore and discuss the functioning of commodity teams in a global sourcing context. Specifically, the study aimed at identifying factors that may influence team members' motivation to participate in activities that create...... opportunities for synergy and coordination of purchasing. In the teams studied, motivation appeared to be influenced to some degree by a number of factors, including rewards, leadership behaviours, goal setting, and the career goals of the commodity team members. In some cases, inconsistencies between...

  1. The neurobiology of opiate motivation.

    Science.gov (United States)

    Ting-A-Kee, Ryan; van der Kooy, Derek

    2012-10-01

    Opiates are a highly addictive class of drugs that have been reported to possess both dopamine-dependent and dopamine-independent rewarding properties. The search for how, if at all, these distinct mechanisms of motivation are related is of great interest in drug addiction research. Recent electrophysiological, molecular, and behavioral work has greatly improved our understanding of this process. In particular, the signaling properties of GABA(A) receptors located on GABA neurons in the ventral tegmental area (VTA) appear to be crucial to understanding the interplay between dopamine-dependent and dopamine-independent mechanisms of opiate motivation.

  2. Conditions and Motivations to Undertake

    Directory of Open Access Journals (Sweden)

    Flor Ángela Marulanda Valencia

    2017-02-01

    Full Text Available This study aims at deepening in the analysis of motivations shown by a group of entrepreneurs in Medellin, Antioquia. It also describes the different perceptions about the enablers and obstacles for the development of entrepreneurship in appropriate environments to promote it. It was found that independence was the principal motivation for entrepreneurship and that the city offered the most favourable environment to foster it. Additionally, it was found that the most important obstacle to develop it was the difficulties to access a bank credit.

  3. Motivation and second language acquisition

    OpenAIRE

    Steve Buckledee

    2007-01-01

    A feature of Italian universities is the high student drop-out rate in nearly all degree courses. It is likely that among the causes of this phenomenon a significant factor is loss of motivation. This study represents the first stage of a longitudinal research project aimed at monitoring students’ motivation levels over a three-year period. At the beginning of the academic year 2008-2009 a questionnaire was administered to 150 newly enrolled students of English at the University of Cagliari i...

  4. Data visualisations as motivational technologies

    DEFF Research Database (Denmark)

    Staunæs, Dorthe; Wied, Kia

    2016-01-01

    This paper aims to contribute with an (affirmative) critique of current tendencies to govern and educate students’ motivation through visualisations. The paper explores how educational policy with a focus on motivating improved learning for ‘all’ children is brought into the lived life of schooling...... through the invention and increased use of (small data) visualisations. Different forms of visualisation techniques such as for instance visible learning (Hattie, 2009; Nottingham, 2013) and more locally designed concepts (as True North, Rubrics e.g.) are enacted to enhance learning and performance among...

  5. Motivation in Second Language Acquisition

    Institute of Scientific and Technical Information of China (English)

    GAO Ya

    2015-01-01

    Second language acquisition is a complex process which involves various factors. The factors can be put into two cate⁃gories:social factors and learner factors. Each category includes a number of factors. The factors such as motivation, age, learning strategies and others such as personality, aptitude are also mutually related. Among all of those factors, motivation plays a very im⁃portant role in the second language acquisition. In this essay, the author will discuss the key factors that affect the outcome of the process.

  6. The relationship in motivational interviewing.

    Science.gov (United States)

    Moyers, Theresa B

    2014-09-01

    The therapeutic relationship in motivational interviewing is hypothesized to have both a direct impact on client outcomes as well as facilitating the emergence of client language in favor of change. The nature of this relationship is characterized by empathy, partnership, and support of the client's autonomy commonly called the spirit of the method. This article explores the implications of this spirit on the practice and understanding of motivational interviewing, including common misconceptions attributable to a misunderstanding of the role of the relationship. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  7. Regulation of Motivation: Students' Motivation Management in Online Collaborative Groupwork

    Science.gov (United States)

    Xu, Jianzhong; Du, Jianxia

    2013-01-01

    Background: Online learning is becoming a global phenomenon and has a steadily growing influence on how learning is delivered at universities worldwide. Motivation of students, however, has become one of the most serious problems in one important aspect of online learning--online collaborative groupwork or online group homework. It is surprising…

  8. Beyond Integrative Motivation: The Development and Influence of Assimilative Motivation.

    Science.gov (United States)

    Graham, C. Ray

    Research suggests that assimilative motivation is largely responsible for the development of native-like speech in both first and second languages. Analysis of anecdotal evidence of early bilingual development, studies of dialect acquisition, bilingual immersion programs, and studies of language pidginization illustrating the development of…

  9. Quantum Curves and $D$-Modules

    CERN Document Server

    Dijkgraaf, Robbert; Sulkowski, Piotr

    2009-01-01

    In this article we continue our study of chiral fermions on a quantum curve. This system is embedded in string theory as an I-brane configuration, which consists of D4 and D6-branes intersecting along a holomorphic curve in a complex surface, together with a B-field. Mathematically, it is described by a holonomic D-module. Here we focus on spectral curves, which play a prominant role in the theory of (quantum) integrable hierarchies. We show how to associate a quantum state to the I-brane system, and subsequently how to compute quantum invariants. As a first example, this yields an insightful formulation of (double scaled as well as general Hermitian) matrix models. Secondly, our formalism elegantly reconstructs the complete dual Nekrasov-Okounkov partition function from a quantum Seiberg-Witten curve.

  10. Quantum curves and Script D-modules

    Science.gov (United States)

    Dijkgraaf, Robbert; Hollands, Lotte; Sułkowski, Piotr

    2009-11-01

    In this article we continue our study of chiral fermions on a quantum curve. This system is embedded in string theory as an I-brane configuration, which consists of D4 and D6-branes intersecting along a holomorphic curve in a complex surface, together with a B-field. Mathematically, it is described by a holonomic Script D-module. Here we focus on spectral curves, which play a prominent role in the theory of (quantum) integrable hierarchies. We show how to associate a quantum state to the I-brane system, and subsequently how to compute quantum invariants. As a first example, this yields an insightful formulation of (double scaled as well as general Hermitian) matrix models. Secondly, we formulate c = 1 string theory in this language. Finally, our formalism elegantly reconstructs the complete dual Nekrasov-Okounkov partition function from a quantum Seiberg-Witten curve.

  11. Relation among C-curve characterization diagrams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As three control points are fixed and the fourth control point varies, the planar cubic C-curve may take on a loop, a cusp, or zero to two inflection points, depending on the position of the moving point. The plane can, therefore, be partitioned into regions labelled according to the characterization of the curve when the fourth point is in each region. This partitioned plane is called a "characterization diagram". By moving one of the control points but fixing the rest, one can induce different characterization diagrams. In this paper, we investigate the relation among all different characterization diagrams of cubic C-curves based on the singularity conditions proposed by Yang and Wang (2004). We conclude that, no matter what the C-curve type is or which control point varies, the characterization diagrams can be obtained by cutting a common 3D characterization space with a corresponding plane.

  12. Holomorphic Cartan geometries and rational curves

    CERN Document Server

    Biswas, Indranil

    2010-01-01

    We prove that any compact K\\"ahler manifold bearing a holomorphic Cartan geometry contains a rational curve just when the Cartan geometry is inherited from a holomorphic Cartan geometry on a lower dimensional compact K\\"ahler manifold.

  13. Transmission of wave energy in curved ducts

    Science.gov (United States)

    Rostafinski, W.

    1973-01-01

    A formation of wave energy flow was developed for motion in curved ducts. A parametric study over a range of frequencies determined the ability of circular bends to transmit energy for the case of perfectly rigid walls.

  14. Halpha rotation curves the soft core question

    CERN Document Server

    Marchesini, D; Chincarini, G L; Firmani, C; Conconi, P; Molinari, E; Zacchei, A

    2002-01-01

    We present good resolution Halpha rotation curves of 6 galaxies: late-type dwarf and low surface brightness galaxies (LSB) for which accurate HI rotation curves are available from the literature. Observations are carried out at Telescopio Nazionale Galileo (TNG). For LSB F583-1 an innovative dispersing element was used, the Volume Phase Holographic (VPH) with a dispersion of about 0.35 A pxl^{-1}. From our analysis we find good agreement between the Halpha data and the HI observations concluding that the HI data for these galaxies suffer very little from beam smearing. We show that the optical rotation curves of these dark matter dominated galaxies are best fitted by the Burkert profile. In the center of galaxies, where the N-body simulations predict cusp cores and fast rising rotation curves, our data seem to be in better agreement with the presence of soft cores.

  15. Automorphisms of double coverings of curves

    CERN Document Server

    Torres, F

    1994-01-01

    We study automorphisms of curves that commute with each other. We prove that the order and the number of fixed points of one of them satisfy certain relations involving those of the other. Then, we specialize our results to the case of double coverings of curves. For instance, if the genus of the curve is at least 4\\gamma+2 and \\gamma \\geqq 1 (\\gamma = the genus of the covered curve) we prove that the order of an automorphism is bounded above by 2\\gamma+1 (resp. 4\\gamma+2) provided it is prime (resp. it has at least five fixed points). We also improve Farkas' bound on the number of fixed points namely 4\\gamma+4 by showing that it involves the order of the automorphism except in the case of even order when such an improvement is obtained provided the automorphism and the \\gamma-involution has at least one common fixed point.

  16. ARC Code TI: ROC Curve Code Augmentation

    Data.gov (United States)

    National Aeronautics and Space Administration — ROC (Receiver Operating Characteristic) curve Code Augmentation was written by Rodney Martin and John Stutz at NASA Ames Research Center and is a modification of ROC...

  17. KAIT Fermi AGN Light-Curve Reservoir

    Data.gov (United States)

    National Aeronautics and Space Administration — This web page shows the light curves of a total of 163 AGNs that are monitored by KAIT with average cadence of 3 days. These are unfiltered observations; in...

  18. Bounded Population Growth: A Curve Fitting Lesson.

    Science.gov (United States)

    Mathews, John H.

    1992-01-01

    Presents two mathematical methods for fitting the logistic curve to population data supplied by the U.S. Census Bureau utilizing computer algebra software to carry out the computations and plot graphs. (JKK)

  19. Rational Curves on Calabi-Yau Threefolds

    CERN Document Server

    Katz, S

    1992-01-01

    The point is to compare the mathematical meaning of the ``number of rational curves on a Calabi-Yau threefold'' to the meaning ascribed to the same notion by string theorists. By considering mirror symmetry applied to conformal field theories corresponding to strings propagating in quintic hypersurfaces in projective 4-space, Candelas, de la Ossa, Green and Parkes calculated the ``number of rational curves on the hypersurface'' by comparing three point functions. Actually, the number of curves may be infinite for special examples; what is really being calculated is a path integral. The point of this talk is to give mathematical techniques and examples for computing the finite number that ``should'' correspond to an infinite family of curves (which coincides with that given by the path integral in every known instance), and to suggest that these techniques should provide the answer to the not yet solved problem of how to calculate instanton corrections to the three point function in general.

  20. Contracts, Phillips Curve and Monetary Policy

    Directory of Open Access Journals (Sweden)

    Félix Jiménez

    2016-02-01

    Full Text Available This paper shows how to obtain a short run aggregate supply curve when there are explicit orimplicit contracts. In the same way it is possible to obtain an expectation augmented Phillips curve. Then, a monetary policy is incorporated to the short run aggregate supply curve or to the Phillips curve in order to model the Central Bank reaction when the actual inflation deviates from the target inflation. Then a model with a Central Bank welfare lost function is developed in order to obtain an optimal monetary policy rule which modifies the synthetic version of the Taylor Rule. This model allows making short run comparative static analyses.