Science.gov

Sample records for posteriori parameter choice

  1. Marginal Maximum A Posteriori Item Parameter Estimation for the Generalized Graded Unfolding Model

    ERIC Educational Resources Information Center

    Roberts, James S.; Thompson, Vanessa M.

    2011-01-01

    A marginal maximum a posteriori (MMAP) procedure was implemented to estimate item parameters in the generalized graded unfolding model (GGUM). Estimates from the MMAP method were compared with those derived from marginal maximum likelihood (MML) and Markov chain Monte Carlo (MCMC) procedures in a recovery simulation that varied sample size,…

  2. Parameter Choices for Approximation by Harmonic Splines

    NASA Astrophysics Data System (ADS)

    Gutting, Martin

    2016-04-01

    The approximation by harmonic trial functions allows the construction of the solution of boundary value problems in geoscience, e.g., in terms of harmonic splines. Due to their localizing properties regional modeling or the improvement of a global model in a part of the Earth's surface is possible with splines. Fast multipole methods have been developed for some cases of the occurring kernels to obtain a fast matrix-vector multiplication. The main idea of the fast multipole algorithm consists of a hierarchical decomposition of the computational domain into cubes and a kernel approximation for the more distant points. This reduces the numerical effort of the matrix-vector multiplication from quadratic to linear in reference to the number of points for a prescribed accuracy of the kernel approximation. The application of the fast multipole method to spline approximation which also allows the treatment of noisy data requires the choice of a smoothing parameter. We investigate different methods to (ideally automatically) choose this parameter with and without prior knowledge of the noise level. Thereby, the performance of these methods is considered for different types of noise in a large simulation study. Applications to gravitational field modeling are presented as well as the extension to boundary value problems where the boundary is the known surface of the Earth itself.

  3. An adaptive regularization parameter choice strategy for multispectral bioluminescence tomography

    SciTech Connect

    Feng Jinchao; Qin Chenghu; Jia Kebin; Han Dong; Liu Kai; Zhu Shouping; Yang Xin; Tian Jie

    2011-11-15

    Purpose: Bioluminescence tomography (BLT) provides an effective tool for monitoring physiological and pathological activities in vivo. However, the measured data in bioluminescence imaging are corrupted by noise. Therefore, regularization methods are commonly used to find a regularized solution. Nevertheless, for the quality of the reconstructed bioluminescent source obtained by regularization methods, the choice of the regularization parameters is crucial. To date, the selection of regularization parameters remains challenging. With regards to the above problems, the authors proposed a BLT reconstruction algorithm with an adaptive parameter choice rule. Methods: The proposed reconstruction algorithm uses a diffusion equation for modeling the bioluminescent photon transport. The diffusion equation is solved with a finite element method. Computed tomography (CT) images provide anatomical information regarding the geometry of the small animal and its internal organs. To reduce the ill-posedness of BLT, spectral information and the optimal permissible source region are employed. Then, the relationship between the unknown source distribution and multiview and multispectral boundary measurements is established based on the finite element method and the optimal permissible source region. Since the measured data are noisy, the BLT reconstruction is formulated as l{sub 2} data fidelity and a general regularization term. When choosing the regularization parameters for BLT, an efficient model function approach is proposed, which does not require knowledge of the noise level. This approach only requests the computation of the residual and regularized solution norm. With this knowledge, we construct the model function to approximate the objective function, and the regularization parameter is updated iteratively. Results: First, the micro-CT based mouse phantom was used for simulation verification. Simulation experiments were used to illustrate why multispectral data were used

  4. A Posteriori Transit Probabilities

    NASA Astrophysics Data System (ADS)

    Stevens, Daniel J.; Gaudi, B. Scott

    2013-08-01

    masses in these regimes. We therefore suggest that companions with minimum masses in these regimes might be better-than-expected targets for transit follow-up, and we identify promising targets from RV-detected planets in the literature. Finally, we consider the uncertainty in the transit probability arising from uncertainties in the input parameters, and the effect of ignoring the dependence of the transit probability on the true semimajor axis on i.

  5. A-posteriori error estimation for second order mechanical systems

    NASA Astrophysics Data System (ADS)

    Ruiner, Thomas; Fehr, Jörg; Haasdonk, Bernard; Eberhard, Peter

    2012-06-01

    One important issue for the simulation of flexible multibody systems is the reduction of the flexible bodies degrees of freedom. As far as safety questions are concerned knowledge about the error introduced by the reduction of the flexible degrees of freedom is helpful and very important. In this work, an a-posteriori error estimator for linear first order systems is extended for error estimation of mechanical second order systems. Due to the special second order structure of mechanical systems, an improvement of the a-posteriori error estimator is achieved. A major advantage of the a-posteriori error estimator is that the estimator is independent of the used reduction technique. Therefore, it can be used for moment-matching based, Gramian matrices based or modal based model reduction techniques. The capability of the proposed technique is demonstrated by the a-posteriori error estimation of a mechanical system, and a sensitivity analysis of the parameters involved in the error estimation process is conducted.

  6. CHOICE OF PROTON DRIVER PARAMETERS FOR A NEUTRINO FACTORY.

    SciTech Connect

    KIRK, H.G.; BERG, J.S.; FERNOW, R.C.; GALLARDO, J.C.; SIMOS, N.; WENG, W.

    2006-06-23

    We discuss criteria for designing an optimal ''green field'' proton driver for a neutrino factory. The driver parameters are determined by considerations of space charge, power capabilities of the target, beam loading and available RF peak power.

  7. Choice.

    PubMed

    Greenberg, Jay

    2008-09-01

    Understanding how and why analysands make the choices they do is central to both the clinical and the theoretical projects of psychoanalysis. And yet we know very little about the process of choice or about the relationship between choices and motives. A striking parallel is to be found between the ways choice is narrated in ancient Greek texts and the experience of analysts as they observe patients making choices in everyday clinical work. Pursuing this convergence of classical and contemporary sensibilities will illuminate crucial elements of the various meanings of choice, and of the way that these meanings change over the course of psychoanalytic treatment. PMID:18802123

  8. Specifics of Mode Parameters Choice Under Twin Arc Welding of Fillet Welds

    NASA Astrophysics Data System (ADS)

    Melnikov, A. U.; Fiveyskiy, A. M.; Sholokhov, M. A.

    2016-04-01

    The present article covers the specifics of mode parameters choice under twin arc welding of fillet welds. The necessity of mode parameters adjustment at the second arc due to heated metal of the first arc was proven. The obtained correction indexes allow us to determine with satisfactory accuracy the mode parameters under given dimensions of weld joint.

  9. Choice of Proton Driver Parameters for a Neutrino Factory

    SciTech Connect

    Kirk,H.G.; Berg, J. S.; Fernow, R. C.; Gallardo, J. C.; Simos, N.; Weng, W.-T.; Brooks, S.

    2006-06-26

    We discuss criteria for designing an optimal 'green field' proton driver for a neutrino factory. The driver parameters are determined by considerations of space charge, power capabilities of the target, beam loading and available RF peak power. A neutrino factory may be the best experimental tool to unravel the physics involved in neutrino oscillation and CP violation phenomena [1]. To have sufficient neutrino flux for acceptable physics results within 5 years requires about 10{sup 22} protons on target per year, which corresponds to 1-4 MW of proton beam power from the proton driver depending on the beam energy. In the past, there were individual proposals from different laboratories of a particular design of proton driver capable of delivering beam power from 2 to 4 MW, without consistent attention paid to the needs or requirements from the downstream systems. In this study, we try to identify the requirements from those down stream systems first, then see whether it is possible to design a proton driver to meet those needs. Such a study will also assist site specific proposals to further improve on their designs to better serve the need of a proton driver for neutrino factory applications.

  10. Method study of parameter choice for a circular proton-proton collider

    NASA Astrophysics Data System (ADS)

    Su, Feng; Gao, Jie; Xiao, Ming; Wang, Dou; Wang, Yi-Wei; Bai, Sha; Bian, Tian-Jian

    2016-01-01

    In this paper we show a systematic method of appropriate parameter choice for a circular proton-proton collider by using an analytical expression for the beam-beam tune shift limit, starting from a given design goal and technical limitations. A suitable parameter space has been explored. Based on the parameter scan, sets of appropriate parameters designed for a 50 km and 100 km circular proton-proton collider are proposed. Supported by National Natural Science Foundation of China (11175192)

  11. Empirical estimation of consistency parameter in intertemporal choice based on Tsallis’ statistics

    NASA Astrophysics Data System (ADS)

    Takahashi, Taiki; Oono, Hidemi; Radford, Mark H. B.

    2007-07-01

    Impulsivity and inconsistency in intertemporal choice have been attracting attention in econophysics and neuroeconomics. Although loss of self-control by substance abusers is strongly related to their inconsistency in intertemporal choice, researchers in neuroeconomics and psychopharmacology have usually studied impulsivity in intertemporal choice using a discount rate (e.g. hyperbolic k), with little effort being expended on parameterizing subject's inconsistency in intertemporal choice. Recent studies using Tsallis’ statistics-based econophysics have found a discount function (i.e. q-exponential discount function), which may continuously parameterize a subject's consistency in intertemporal choice. In order to examine the usefulness of the consistency parameter (0⩽q⩽1) in the q-exponential discounting function in behavioral studies, we experimentally estimated the consistency parameter q in Tsallis’ statistics-based discounting function by assessing the points of subjective equality (indifference points) at seven delays (1 week-25 years) in humans (N=24). We observed that most (N=19) subjects’ intertemporal choice was completely inconsistent ( q=0, i.e. hyperbolic discounting), the mean consistency (0⩽q⩽1) was smaller than 0.5, and only one subject had a completely consistent intertemporal choice ( q=1, i.e. exponential discounting). There was no significant correlation between impulsivity and inconsistency parameters. Our results indicate that individual differences in consistency in intertemporal choice can be parameterized by introducing a q-exponential discount function and most people discount delayed rewards hyperbolically, rather than exponentially (i.e. mean q is smaller than 0.5). Further, impulsivity and inconsistency in intertemporal choice can be considered as separate behavioral tendencies. The usefulness of the consistency parameter q in psychopharmacological studies of addictive behavior was demonstrated in the present study.

  12. [ETHICAL PRINCIPALS AND A POSTERIORI JUSTIFICATIONS].

    PubMed

    Heintz, Monica

    2015-12-01

    It is difficult to conceive that the human being, while being the same everywhere, could be cared for in such different ways in other societies. Anthropologists acknowledge that the diversity of cultures implies a diversity of moral values, thus that in a multicultural society the individual could draw upon different moral frames to justify the peculiarities of her/his demand of care. But how could we determine what is the moral frame that catalyzes behaviour while all we can record are a posteriori justifications of actions? In most multicultural societies where several moralframes coexist, there is an implicit hierarchy between ethical systems derived from a hierarchy of power which falsifies these a posteriori justifications. Moreover anthropologists often fail to acknowledge that individual behaviour does not always reflect individual values, but is more often the result of negotiations between the moralframes available in society and her/his own desires and personal experience. This is certainly due to the difficulty to account for a dynamic and complex interplay of moral values that cannot be analysed as a system. The impact of individual experience on the way individuals give or receive care could also be only weakly linked to a moral system even when this reference comes up explicitly in the a posteriori justifications. PMID:27120823

  13. Parameter choice matters: validating probe parameters for use in mixed-solvent simulations.

    PubMed

    Lexa, Katrina W; Goh, Garrett B; Carlson, Heather A

    2014-08-25

    Probe mapping is a common approach for identifying potential binding sites in structure-based drug design; however, it typically relies on energy minimizations of probes in the gas phase and a static protein structure. The mixed-solvent molecular dynamics (MixMD) approach was recently developed to account for full protein flexibility and solvation effects in hot-spot mapping. Our first study used only acetonitrile as a probe, and here, we have augmented the set of functional group probes through careful testing and parameter validation. A diverse range of probes are needed in order to map complex binding interactions. A small variation in probe parameters can adversely effect mixed-solvent behavior, which we highlight with isopropanol. We tested 11 solvents to identify six with appropriate behavior in TIP3P water to use as organic probes in the MixMD method. In addition to acetonitrile and isopropanol, we have identified acetone, N-methylacetamide, imidazole, and pyrimidine. These probe solvents will enable MixMD studies to recover hydrogen-bonding sites, hydrophobic pockets, protein-protein interactions, and aromatic hotspots. Also, we show that ternary-solvent systems can be incorporated within a single simulation. Importantly, these binary and ternary solvents do not require artificial repulsion terms like other methods. Within merely 5 ns, layered solvent boxes become evenly mixed for soluble probes. We used radial distribution functions to evaluate solvent behavior, determine adequate mixing, and confirm the absence of phase separation. We recommend that radial distribution functions should be used to assess adequate sampling in all mixed-solvent techniques rather than the current practice of examining the solvent ratios at the edges of the solvent box. PMID:25058662

  14. Robust maximum a posteriori image super-resolution

    NASA Astrophysics Data System (ADS)

    Vrigkas, Michalis; Nikou, Christophoros; Kondi, Lisimachos P.

    2014-07-01

    A global robust M-estimation scheme for maximum a posteriori (MAP) image super-resolution which efficiently addresses the presence of outliers in the low-resolution images is proposed. In iterative MAP image super-resolution, the objective function to be minimized involves the highly resolved image, a parameter controlling the step size of the iterative algorithm, and a parameter weighing the data fidelity term with respect to the smoothness term. Apart from the robust estimation of the high-resolution image, the contribution of the proposed method is twofold: (1) the robust computation of the regularization parameters controlling the relative strength of the prior with respect to the data fidelity term and (2) the robust estimation of the optimal step size in the update of the high-resolution image. Experimental results demonstrate that integrating these estimations into a robust framework leads to significant improvement in the accuracy of the high-resolution image.

  15. A Small-Sample Choice of the Tuning Parameter in Ridge Regression

    PubMed Central

    Boonstra, Philip S.; Mukherjee, Bhramar; Taylor, Jeremy M. G.

    2015-01-01

    We propose new approaches for choosing the shrinkage parameter in ridge regression, a penalized likelihood method for regularizing linear regression coefficients, when the number of observations is small relative to the number of parameters. Existing methods may lead to extreme choices of this parameter, which will either not shrink the coefficients enough or shrink them by too much. Within this “small-n, large-p” context, we suggest a correction to the common generalized cross-validation (GCV) method that preserves the asymptotic optimality of the original GCV. We also introduce the notion of a “hyperpenalty”, which shrinks the shrinkage parameter itself, and make a specific recommendation regarding the choice of hyperpenalty that empirically works well in a broad range of scenarios. A simple algorithm jointly estimates the shrinkage parameter and regression coefficients in the hyperpenalized likelihood. In a comprehensive simulation study of small-sample scenarios, our proposed approaches offer superior prediction over nine other existing methods. PMID:26985140

  16. On the choice of GARCH parameters for efficient modelling of real stock price dynamics

    NASA Astrophysics Data System (ADS)

    Pokhilchuk, K. A.; Savel'ev, S. E.

    2016-04-01

    We propose two different methods for optimal choice of GARCH(1,1) parameters for the efficient modelling of stock prices by using a particular return series. Using (as an example) stock return data for Intel Corporation, we vary parameters to fit the average volatility as well as fourth (linked to kurtosis of data) and eighth statistical moments and observe pure convergence of our simulated eighth moment to the stock data. Results indicate that fitting higher-order moments of a return series might not be an optimal approach for choosing GARCH parameters. In contrast, the simulated exponent of the Fourier spectrum decay is much less noisy and can easily fit the corresponding decay of the empirical Fourier spectrum of the used return series of Intel stock, allowing us to efficiently define all GARCH parameters. We compare the estimates of GARCH parameters obtained by fitting price data Fourier spectra with the ones obtained from standard software packages and conclude that the obtained estimates here are deeper in the stability region of parameters. Thus, the proposed method of using Fourier spectra of stock data to estimate GARCH parameters results in a more robust and stable stochastic process but with a shorter characteristic autocovariance time.

  17. Maximum a posteriori decoder for digital communications

    NASA Technical Reports Server (NTRS)

    Altes, Richard A. (Inventor)

    1997-01-01

    A system and method for decoding by identification of the most likely phase coded signal corresponding to received data. The present invention has particular application to communication with signals that experience spurious random phase perturbations. The generalized estimator-correlator uses a maximum a posteriori (MAP) estimator to generate phase estimates for correlation with incoming data samples and for correlation with mean phases indicative of unique hypothesized signals. The result is a MAP likelihood statistic for each hypothesized transmission, wherein the highest value statistic identifies the transmitted signal.

  18. Ridge Regression in Prediction Problems: Automatic Choice of the Ridge Parameter

    PubMed Central

    Cule, Erika; De Iorio, Maria

    2013-01-01

    To date, numerous genetic variants have been identified as associated with diverse phenotypic traits. However, identified associations generally explain only a small proportion of trait heritability and the predictive power of models incorporating only known-associated variants has been small. Multiple regression is a popular framework in which to consider the joint effect of many genetic variants simultaneously. Ordinary multiple regression is seldom appropriate in the context of genetic data, due to the high dimensionality of the data and the correlation structure among the predictors. There has been a resurgence of interest in the use of penalised regression techniques to circumvent these difficulties. In this paper, we focus on ridge regression, a penalised regression approach that has been shown to offer good performance in multivariate prediction problems. One challenge in the application of ridge regression is the choice of the ridge parameter that controls the amount of shrinkage of the regression coefficients. We present a method to determine the ridge parameter based on the data, with the aim of good performance in high-dimensional prediction problems. We establish a theoretical justification for our approach, and demonstrate its performance on simulated genetic data and on a real data example. Fitting a ridge regression model to hundreds of thousands to millions of genetic variants simultaneously presents computational challenges. We have developed an R package, ridge, which addresses these issues. Ridge implements the automatic choice of ridge parameter presented in this paper, and is freely available from CRAN. PMID:23893343

  19. Robust contrast source inversion method with automatic choice rule of regularization parameters for ultrasound waveform tomography

    NASA Astrophysics Data System (ADS)

    Lin, Hongxiang; Azuma, Takashi; Qu, Xiaolei; Takagi, Shu

    2016-07-01

    We consider ultrasound waveform tomography using an ultrasound prototype equipped with the ring-array transducers. For this purpose, we use robust contrast source inversion (robust CSI), viz extended contrast source inversion, to reconstruct the sound-speed image from the wave-field data. The robust CSI method is implemented by the alternating minimization method. An automatic choice rule is employed into the alternating minimization method in order to heuristically determine a suitable regularization parameter while iterating. We prove the convergence of this algorithm. The numerical examples show that the robust CSI method with the automatic choice rule improves the spatial resolution of medical images and enhances the robustness, even when the wave-field data of a wavelength of 6.16 mm contaminated by 5% noise are used. The numerical results also show that the images reconstructed by the proposed method yield a spatial resolution of approximately half the wavelength that may be adequate for imaging a breast tumor at Stage I.

  20. Parameters of rewards on choice behavior in Siamese fighting fish (Betta splendens).

    PubMed

    Shapiro, Martin S; Jensen, Ashley L

    2009-09-01

    Five experiments were conducted with Siamese fighting fish (Betta splendens) to investigate how choices in a T-maze were affected by parameters of a social reward (aggression display to another male): presence or absence, amount, delay and distance traveled. Bettas showed a preference for the side associated with the presence of another male rather than the side associated with nothing (Exp 1), a greater length of time of the reward (Exp 2) and shorter delay (Exp 3). The animals were indifferent when one side offered a longer delay to a longer reward time compared with a shorter delay to a shorter reward time (Exp 4). What was most surprising, however, was that fish preferred to choose the side that was associated with swimming a greater distance to reach an opponent male (Exp 5). These experiments demonstrate that, while some parameters of a visual reward affect behavior in predictable ways (greater amount, shorter delay), the complex motivations underlying inter-male aggression can produce what appear to be paradoxical results. PMID:19615613

  1. Optimal choice of the parameters for ventilation and methane drainage in a longwall face with caving

    SciTech Connect

    Dziurzynski, W.; Nawrat, S.

    1995-12-31

    An increasing concentration of coal production, especially in the circumstances of intensive methane inflow makes the coal mine managing staff apply new techniques of safe mining. It paves also the way for scientists to develop new directions of investigations and implementation of state-of-the-art technical solutions. Simultaneously, it could be noticed that the funds assigned for expansive {open_quote}in situ{close_quotes} investigation are continuously decreasing. Better and better results are reached when applying computer technique in calculations of the parameters of ventilation process. Recent theoretical and experimental investigations of air and gas (methane) flow in longwall areas with caving, combined with the implementation of methane drainage system allowed to create, a mathematical model and consequently to elaborate a computer supported numerical simulation of discussed phenomena. The mathematical model has been modified and the simulation program was prepared in such a way that the software is convenient for a user looking for an optimal solution. The paper presented the methodology of optimal choice of following parameters: (1) ventilation system; and (2) rate of flow through the wall. The procedure takes into consideration keeping a safe level of concentration methane in air flowing through the longwall as well as the criterion of maximum methane concentration within the methane drainage pipe line. Results of variant computer simulation regarding the longwall with caving are shown in graphs and tables.

  2. Minimization of multi-penalty functionals by alternating iterative thresholding and optimal parameter choices

    NASA Astrophysics Data System (ADS)

    Naumova, Valeriya; Peter, Steffen

    2014-12-01

    Inspired by several recent developments in regularization theory, optimization, and signal processing, we present and analyze a numerical approach to multi-penalty regularization in spaces of sparsely represented functions. The sparsity prior is motivated by the largely expected geometrical/structured features of high-dimensional data, which may not be well-represented in the framework of typically more isotropic Hilbert spaces. In this paper, we are particularly interested in regularizers which are able to correctly model and separate the multiple components of additively mixed signals. This situation is rather common as pure signals may be corrupted by additive noise. To this end, we consider a regularization functional composed by a data-fidelity term, where signal and noise are additively mixed, a non-smooth and non-convex sparsity promoting term, and a penalty term to model the noise. We propose and analyze the convergence of an iterative alternating algorithm based on simple iterative thresholding steps to perform the minimization of the functional. By means of this algorithm, we explore the effect of choosing different regularization parameters and penalization norms in terms of the quality of recovering the pure signal and separating it from additive noise. For a given fixed noise level numerical experiments confirm a significant improvement in performance compared to standard one-parameter regularization methods. By using high-dimensional data analysis methods such as principal component analysis, we are able to show the correct geometrical clustering of regularized solutions around the expected solution. Eventually, for the compressive sensing problems considered in our experiments we provide a guideline for a choice of regularization norms and parameters.

  3. Electron transport in magnetrons by a posteriori Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Costin, C.; Minea, T. M.; Popa, G.

    2014-02-01

    Electron transport across magnetic barriers is crucial in all magnetized plasmas. It governs not only the plasma parameters in the volume, but also the fluxes of charged particles towards the electrodes and walls. It is particularly important in high-power impulse magnetron sputtering (HiPIMS) reactors, influencing the quality of the deposited thin films, since this type of discharge is characterized by an increased ionization fraction of the sputtered material. Transport coefficients of electron clouds released both from the cathode and from several locations in the discharge volume are calculated for a HiPIMS discharge with pre-ionization operated in argon at 0.67 Pa and for very short pulses (few µs) using the a posteriori Monte Carlo simulation technique. For this type of discharge electron transport is characterized by strong temporal and spatial dependence. Both drift velocity and diffusion coefficient depend on the releasing position of the electron cloud. They exhibit minimum values at the centre of the race-track for the secondary electrons released from the cathode. The diffusion coefficient of the same electrons increases from 2 to 4 times when the cathode voltage is doubled, in the first 1.5 µs of the pulse. These parameters are discussed with respect to empirical Bohm diffusion.

  4. A model selection algorithm for a posteriori probability estimation with neural networks.

    PubMed

    Arribas, Juan Ignacio; Cid-Sueiro, Jesús

    2005-07-01

    This paper proposes a novel algorithm to jointly determine the structure and the parameters of a posteriori probability model based on neural networks (NNs). It makes use of well-known ideas of pruning, splitting, and merging neural components and takes advantage of the probabilistic interpretation of these components. The algorithm, so called a posteriori probability model selection (PPMS), is applied to an NN architecture called the generalized softmax perceptron (GSP) whose outputs can be understood as probabilities although results shown can be extended to more general network architectures. Learning rules are derived from the application of the expectation-maximization algorithm to the GSP-PPMS structure. Simulation results show the advantages of the proposed algorithm with respect to other schemes. PMID:16121722

  5. Superconvergence and recovery type a posteriori error estimation for hybrid stress finite element method

    NASA Astrophysics Data System (ADS)

    Bai, YanHong; Wu, YongKe; Xie, XiaoPing

    2016-09-01

    Superconvergence and a posteriori error estimators of recovery type are analyzed for the 4-node hybrid stress quadrilateral finite element method proposed by Pian and Sumihara (Int. J. Numer. Meth. Engrg., 1984, 20: 1685-1695) for linear elasticity problems. Uniform superconvergence of order $O(h^{1+\\min\\{\\alpha,1\\}})$ with respect to the Lam\\'{e} constant $\\lambda$ is established for both the recovered gradients of the displacement vector and the stress tensor under a mesh assumption, where $\\alpha>0$ is a parameter characterizing the distortion of meshes from parallelograms to quadrilaterals. A posteriori error estimators based on the recovered quantities are shown to be asymptotically exact. Numerical experiments confirm the theoretical results.

  6. A Two-Stage Algorithm for Origin-Destination Matrices Estimation Considering Dynamic Dispersion Parameter for Route Choice.

    PubMed

    Wang, Yong; Ma, Xiaolei; Liu, Yong; Gong, Ke; Henrickson, Kristian C; Henricakson, Kristian C; Xu, Maozeng; Wang, Yinhai

    2016-01-01

    This paper proposes a two-stage algorithm to simultaneously estimate origin-destination (OD) matrix, link choice proportion, and dispersion parameter using partial traffic counts in a congested network. A non-linear optimization model is developed which incorporates a dynamic dispersion parameter, followed by a two-stage algorithm in which Generalized Least Squares (GLS) estimation and a Stochastic User Equilibrium (SUE) assignment model are iteratively applied until the convergence is reached. To evaluate the performance of the algorithm, the proposed approach is implemented in a hypothetical network using input data with high error, and tested under a range of variation coefficients. The root mean squared error (RMSE) of the estimated OD demand and link flows are used to evaluate the model estimation results. The results indicate that the estimated dispersion parameter theta is insensitive to the choice of variation coefficients. The proposed approach is shown to outperform two established OD estimation methods and produce parameter estimates that are close to the ground truth. In addition, the proposed approach is applied to an empirical network in Seattle, WA to validate the robustness and practicality of this methodology. In summary, this study proposes and evaluates an innovative computational approach to accurately estimate OD matrices using link-level traffic flow data, and provides useful insight for optimal parameter selection in modeling travelers' route choice behavior. PMID:26761209

  7. A Two-Stage Algorithm for Origin-Destination Matrices Estimation Considering Dynamic Dispersion Parameter for Route Choice

    PubMed Central

    Wang, Yong; Ma, Xiaolei; Liu, Yong; Gong, Ke; Henricakson, Kristian C.; Xu, Maozeng; Wang, Yinhai

    2016-01-01

    This paper proposes a two-stage algorithm to simultaneously estimate origin-destination (OD) matrix, link choice proportion, and dispersion parameter using partial traffic counts in a congested network. A non-linear optimization model is developed which incorporates a dynamic dispersion parameter, followed by a two-stage algorithm in which Generalized Least Squares (GLS) estimation and a Stochastic User Equilibrium (SUE) assignment model are iteratively applied until the convergence is reached. To evaluate the performance of the algorithm, the proposed approach is implemented in a hypothetical network using input data with high error, and tested under a range of variation coefficients. The root mean squared error (RMSE) of the estimated OD demand and link flows are used to evaluate the model estimation results. The results indicate that the estimated dispersion parameter theta is insensitive to the choice of variation coefficients. The proposed approach is shown to outperform two established OD estimation methods and produce parameter estimates that are close to the ground truth. In addition, the proposed approach is applied to an empirical network in Seattle, WA to validate the robustness and practicality of this methodology. In summary, this study proposes and evaluates an innovative computational approach to accurately estimate OD matrices using link-level traffic flow data, and provides useful insight for optimal parameter selection in modeling travelers’ route choice behavior. PMID:26761209

  8. Analysis of the geophysical data using a posteriori algorithms

    NASA Astrophysics Data System (ADS)

    Voskoboynikova, Gyulnara; Khairetdinov, Marat

    2016-04-01

    The problems of monitoring, prediction and prevention of extraordinary natural and technogenic events are priority of modern problems. These events include earthquakes, volcanic eruptions, the lunar-solar tides, landslides, falling celestial bodies, explosions utilized stockpiles of ammunition, numerous quarry explosion in open coal mines, provoking technogenic earthquakes. Monitoring is based on a number of successive stages, which include remote registration of the events responses, measurement of the main parameters as arrival times of seismic waves or the original waveforms. At the final stage the inverse problems associated with determining the geographic location and time of the registration event are solving. Therefore, improving the accuracy of the parameters estimation of the original records in the high noise is an important problem. As is known, the main measurement errors arise due to the influence of external noise, the difference between the real and model structures of the medium, imprecision of the time definition in the events epicenter, the instrumental errors. Therefore, posteriori algorithms more accurate in comparison with known algorithms are proposed and investigated. They are based on a combination of discrete optimization method and fractal approach for joint detection and estimation of the arrival times in the quasi-periodic waveforms sequence in problems of geophysical monitoring with improved accuracy. Existing today, alternative approaches to solving these problems does not provide the given accuracy. The proposed algorithms are considered for the tasks of vibration sounding of the Earth in times of lunar and solar tides, and for the problem of monitoring of the borehole seismic source location in trade drilling.

  9. A Posteriori Analysis for Hydrodynamic Simulations Using Adjoint Methodologies

    SciTech Connect

    Woodward, C S; Estep, D; Sandelin, J; Wang, H

    2009-02-26

    This report contains results of analysis done during an FY08 feasibility study investigating the use of adjoint methodologies for a posteriori error estimation for hydrodynamics simulations. We developed an approach to adjoint analysis for these systems through use of modified equations and viscosity solutions. Targeting first the 1D Burgers equation, we include a verification of the adjoint operator for the modified equation for the Lax-Friedrichs scheme, then derivations of an a posteriori error analysis for a finite difference scheme and a discontinuous Galerkin scheme applied to this problem. We include some numerical results showing the use of the error estimate. Lastly, we develop a computable a posteriori error estimate for the MAC scheme applied to stationary Navier-Stokes.

  10. Cognitive Models of Risky Choice: Parameter Stability and Predictive Accuracy of Prospect Theory

    ERIC Educational Resources Information Center

    Glockner, Andreas; Pachur, Thorsten

    2012-01-01

    In the behavioral sciences, a popular approach to describe and predict behavior is cognitive modeling with adjustable parameters (i.e., which can be fitted to data). Modeling with adjustable parameters allows, among other things, measuring differences between people. At the same time, parameter estimation also bears the risk of overfitting. Are…

  11. A Posteriori Restoration of Block Transform-Compressed Data

    NASA Technical Reports Server (NTRS)

    Brown, R.; Boden, A. F.

    1995-01-01

    The Galileo spacecraft will use lossy data compression for the transmission of its science imagery over the low-bandwidth communication system. The technique chosen for image compression is a block transform technique based on the Integer Cosine Transform, a derivative of the JPEG image compression standard. Considered here are two known a posteriori enhancement techniques, which are adapted.

  12. Suitable parameter choice on quantitative morphology of A549 cell in epithelial–mesenchymal transition

    PubMed Central

    Ren, Zhou-Xin; Yu, Hai-Bin; Li, Jian-Sheng; Shen, Jun-Ling; Du, Wen-Sen

    2015-01-01

    Evaluation of morphological changes in cells is an integral part of study on epithelial to mesenchymal transition (EMT), however, only a few papers reported the changes in quantitative parameters and no article compared different parameters for demanding better parameters. In the study, the purpose was to investigate suitable parameters for quantitative evaluation of EMT morphological changes. A549 human lung adenocarcinoma cell line was selected for the study. Some cells were stimulated by transforming growth factor-β1 (TGF-β1) for EMT, and other cells were as control without TGF-β1 stimulation. Subsequently, cells were placed in phase contrast microscope and three arbitrary fields were captured and saved with a personal computer. Using the tools of Photoshop software, some cells in an image were selected, segmented out and exchanged into unique hue, and other part in the image was shifted into another unique hue. The cells were calculated with 29 morphological parameters by Image Pro Plus software. A parameter between cells with or without TGF-β1 stimulation was compared statistically and nine parameters were significantly different between them. Receiver operating characteristic curve (ROC curve) of a parameter was described with SPSS software and F-test was used to compare two areas under the curves (AUCs) in Excel. Among them, roundness and radius ratio were the most AUCs and were significant higher than the other parameters. The results provided a new method with quantitative assessment of cell morphology during EMT, and found out two parameters, roundness and radius ratio, as suitable for quantification. PMID:26182364

  13. Sensitivity of Human Choice to Manipulations of Parameters of Positive and Negative Sound Reinforcement

    ERIC Educational Resources Information Center

    Lambert, Joseph M.

    2013-01-01

    The purpose of this study was to determine whether altering parameters of positive and negative reinforcement in identical ways could influence behavior maintained by each in different ways. Three undergraduate students participated in a series of assessments designed to identify preferred and aversive sounds with similar reinforcing values.…

  14. The Impact of Escape Alternative Position Change in Multiple-Choice Test on the Psychometric Properties of a Test and Its Items Parameters

    ERIC Educational Resources Information Center

    Hamadneh, Iyad Mohammed

    2015-01-01

    This study aimed at investigating the impact changing of escape alternative position in multiple-choice test on the psychometric properties of a test and it's items parameters (difficulty, discrimination & guessing), and estimation of examinee ability. To achieve the study objectives, a 4-alternative multiple choice type achievement test…

  15. Comparing species decisions in a dichotomous choice task: adjusting task parameters improves performance in monkeys.

    PubMed

    Prétôt, Laurent; Bshary, Redouan; Brosnan, Sarah F

    2016-07-01

    In comparative psychology, both similarities and differences among species are studied to better understand the evolution of their behavior. To do so, we first test species in tasks using similar procedures, but if differences are found, it is important to determine their underlying cause(s) (e.g., are they due to ecology, cognitive ability, an artifact of the study, and/or some other factor?). In our previous work, primates performed unexpectedly poorly on an apparently simple two-choice discrimination task based on the natural behavior of cleaner fish, while the fish did quite well. In this task, if the subjects first chose one of the options (ephemeral) they received both food items, but if they chose the other (permanent) option first, the ephemeral option disappeared. Here, we test several proposed explanations for primates' relatively poorer performance. In Study 1, we used a computerized paradigm that differed from the previous test by removing interaction with human experimenters, which may be distracting, and providing a more standardized testing environment. In Study 2, we adapted the computerized paradigm from Study 1 to be more relevant to primate ecology. Monkeys' overall performance in these adapted tasks matched the performance of the fish in the original study, showing that with the appropriate modifications they can solve the task. We discuss these results in light of comparative research, which requires balancing procedural similarity with considerations of how the details of the task or the context may influence how different species perceive and solve tasks differently. PMID:27086302

  16. Parameter Choice and Constraint in Hydrologic Models for Evaluating Land Use Change

    NASA Astrophysics Data System (ADS)

    Jackson, C. R.

    2011-12-01

    Hydrologic models are used to answer questions, from simple, "what is the expected 100-year peak flow for a basin?", to complex, "how will land use change alter flow pathways, flow time series, and water chemistry?" Appropriate model structure and complexity depend on the questions being addressed. Numerous studies of simple transfer models for converting climate signals into streamflows suggest that only three or four parameters are needed. The conceptual corollary to such models is a single hillslope bucket with storage, evapotranspiration, fast flow, and slow flow. While having the benefit of low uncertainty, such models are ill-suited to addressing land use questions. Land use questions require models that can simulate effects of changes in vegetation, alterations of soil characteristics, and resulting changes in flow pathways. For example, minimum goals for a hydrologic model evaluating bioenergy feedstock production might include: 1) calculate Horton overland flow based on surface conductivities and saturated surface flow based on relative moisture content in the topsoils, 2) allow reinfiltration of Horton overland flow created by bare soils, compacted soils, and pavement (roads, logging roads, skid trails, landings), 3) account for root zone depth and LAI in transpiration calculations, 4) allow mixing of hillslope flows in the riparian aquifer, 5) allow separate simulation of the riparian soils and vegetation and upslope soils and vegetation, 6) incorporate important aspects of topography and stratigraphy, and 7) estimate residence times in different flow paths. How many parameters are needed for such a model, and what information beside streamflow can be collected to constrain the parameters? Additional information that can be used for evaluating and testing watershed models are in-situ conductivity measurements, soil porosity, soil moisture dynamics, shallow perched groundwater behavior, interflow occurrence, groundwater behavior, regional ET estimates

  17. Guidelines in the Choice of Parameters for Hybrid Laser Arc Welding with Fiber Lasers

    NASA Astrophysics Data System (ADS)

    Eriksson, I.; Powell, J.; Kaplan, A.

    Laser arc hybrid welding has been a promising technology for three decades and laser welding in combination with gas metal arc welding (GMAW) has shown that it is an extremely promising technique. On the other hand the process is often considered complicated and difficult to set up correctly. An important factor in setting up the hybrid welding process is an understanding of the GMAW process. It is especially important to understand how the wire feed rate and the arc voltage (the two main parameters) affect the process. In this paper the authors show that laser hybrid welding with a 1 μm laser is similar to ordinary GMAW, and several guidelines are therefore inherited by the laser hybrid process.

  18. Dynamics, analytical solutions and choice of parameters for towed space debris with flexible appendages

    NASA Astrophysics Data System (ADS)

    Aslanov, Vladimir S.; Yudintsev, Vadim V.

    2015-01-01

    Active debris removal is one of the promising techniques that will decrease the population of large, non-functional spacecraft (space debris) on orbit. Properties of space debris should be taken into account during planning an active debris removal mission. In this paper the thrusting phase of tethered deorbit of large space debris with flexible appendages is considered. The goal of the work is to investigate the mutual influence of the tether vibrations and the vibrations of flexible appendages during thrusting phase. A mathematical model of the space tug and the towed space debris with flexible appendages is developed. Parameters of the system are determined with assumptions that the system is moving in straight line, avoiding high amplitude vibrations of flexible appendages. The expression of the discriminant indicates that the vibrations of the tether and flexible appendages influence each other. A critical tether stiffness exists for the given space tug mass that should be avoided.

  19. Parameter choices for a muon recirculating linear accelerator from 5 to 63 GeV

    SciTech Connect

    Berg, J. S.

    2014-06-19

    A recirculating linear accelerator (RLA) has been proposed to accelerate muons from 5 to 63 GeV for a muon collider. It should be usable both for a Higgs factory and as a stage for a higher energy collider. First, the constraints due to the beam loading are computed. Next, an expression for the longitudinal emittance growth to lowest order in the longitudinal emittance is worked out. After finding the longitudinal expression, a simplified model that describes the arcs and their approximate expression for the time of flight dependence on energy in those arcs is found. Finally, these results are used to estimate the parameters required for the RLA arcs and the linac phase.

  20. Implications of the subjectivity in hydrologic model choice and parameter identification on the portrayal of climate change impact

    NASA Astrophysics Data System (ADS)

    Mendoza, Pablo; Clark, Martyn; Rajagopalan, Balaji; MIzukami, Naoki; Gutmann, Ethan; Newman, Andy; Barlage, Michael; Brekke, Levi; Arnold, Jeffrey

    2014-05-01

    Climate change studies involve several methodological choices that affect the hydrological sensitivities obtained, including emission scenarios, climate models, downscaling techniques and hydrologic modeling approaches. Among these, hydrologic model structure selection (i.e. the set of equations that describe catchment processes) and parameter identification are particularly relevant and usually have a strong subjective component. This subjectivity is not only limited to engineering applications, but also extends to many of our research studies, resulting in problems such as missing processes in our models, inappropriate parameterizations and compensatory effects of model parameters (i.e. getting the right answers for the wrong reasons). The goal of this research is to assess the impact of our modeling decisions on projected changes in water balance and catchment behavior for future climate scenarios. Additionally, we aim to better understand the relative importance of hydrologic model structures and parameters on the portrayal of climate change impact. Therefore, we compare hydrologic sensitivities coming from four different models structures (PRMS, VIC, Noah and Noah-MP) with those coming from parameter sets identified using different decisions related to model calibration (objective function, multiple local optima and calibration forcing dataset). We found that both model structure selection and parameter estimation strategy (objective function and forcing dataset) affect the direction and magnitude of climate change signal. Furthermore, the relative effect of subjective decisions on projected variations of catchment behavior depends on the hydrologic signature measure analyzed. Finally, parameter sets with similar values of the objective function may not affect current and future changes in water balance, but may lead to very different sensitivities in hydrologic behavior.

  1. A unified approach for a posteriori high-order curved mesh generation using solid mechanics

    NASA Astrophysics Data System (ADS)

    Poya, Roman; Sevilla, Ruben; Gil, Antonio J.

    2016-06-01

    The paper presents a unified approach for the a posteriori generation of arbitrary high-order curvilinear meshes via a solid mechanics analogy. The approach encompasses a variety of methodologies, ranging from the popular incremental linear elastic approach to very sophisticated non-linear elasticity. In addition, an intermediate consistent incrementally linearised approach is also presented and applied for the first time in this context. Utilising a consistent derivation from energy principles, a theoretical comparison of the various approaches is presented which enables a detailed discussion regarding the material characterisation (calibration) employed for the different solid mechanics formulations. Five independent quality measures are proposed and their relations with existing quality indicators, used in the context of a posteriori mesh generation, are discussed. Finally, a comprehensive range of numerical examples, both in two and three dimensions, including challenging geometries of interest to the solids, fluids and electromagnetics communities, are shown in order to illustrate and thoroughly compare the performance of the different methodologies. This comparison considers the influence of material parameters and number of load increments on the quality of the generated high-order mesh, overall computational cost and, crucially, the approximation properties of the resulting mesh when considering an isoparametric finite element formulation.

  2. A unified approach for a posteriori high-order curved mesh generation using solid mechanics

    NASA Astrophysics Data System (ADS)

    Poya, Roman; Sevilla, Ruben; Gil, Antonio J.

    2016-09-01

    The paper presents a unified approach for the a posteriori generation of arbitrary high-order curvilinear meshes via a solid mechanics analogy. The approach encompasses a variety of methodologies, ranging from the popular incremental linear elastic approach to very sophisticated non-linear elasticity. In addition, an intermediate consistent incrementally linearised approach is also presented and applied for the first time in this context. Utilising a consistent derivation from energy principles, a theoretical comparison of the various approaches is presented which enables a detailed discussion regarding the material characterisation (calibration) employed for the different solid mechanics formulations. Five independent quality measures are proposed and their relations with existing quality indicators, used in the context of a posteriori mesh generation, are discussed. Finally, a comprehensive range of numerical examples, both in two and three dimensions, including challenging geometries of interest to the solids, fluids and electromagnetics communities, are shown in order to illustrate and thoroughly compare the performance of the different methodologies. This comparison considers the influence of material parameters and number of load increments on the quality of the generated high-order mesh, overall computational cost and, crucially, the approximation properties of the resulting mesh when considering an isoparametric finite element formulation.

  3. Effects of using a posteriori methods for the conservation of integral invariants. [for weather forecasting

    NASA Technical Reports Server (NTRS)

    Takacs, Lawrence L.

    1988-01-01

    The nature and effect of using a posteriori adjustments to nonconservative finite-difference schemes to enforce integral invariants of the corresponding analytic system are examined. The method of a posteriori integral constraint restoration is analyzed for the case of linear advection, and the harmonic response associated with the a posteriori adjustments is examined in detail. The conservative properties of the shallow water system are reviewed, and the constraint restoration algorithm applied to the shallow water equations are described. A comparison is made between forecasts obtained using implicit and a posteriori methods for the conservation of mass, energy, and potential enstrophy in the complete nonlinear shallow-water system.

  4. Application of a posteriori granddaughter and modified granddaughter designs to determine Holstein haplotype effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A posteriori and modified granddaughter designs were applied to determine haplotype effects for Holstein bulls and cows with BovineSNP50 genotypes. The a posteriori granddaughter design was applied to 52 sire families, each with >100 genotyped sons with genetic evaluations based on progeny tests. Fo...

  5. Application of a posteriori granddaughter and modified granddaughter designs to determine Holstein haplotype effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A posteriori and modified granddaughter designs were applied to determine haplotype effects for Holstein bulls and cows with BovineSNP50 genotypes. The a posteriori granddaughter design was applied to 52 sire families, each with '100 genotyped sons with genetic evaluations based on progeny tests. Fo...

  6. A posteriori operation detection in evolving software models

    PubMed Central

    Langer, Philip; Wimmer, Manuel; Brosch, Petra; Herrmannsdörfer, Markus; Seidl, Martina; Wieland, Konrad; Kappel, Gerti

    2013-01-01

    As every software artifact, also software models are subject to continuous evolution. The operations applied between two successive versions of a model are crucial for understanding its evolution. Generic approaches for detecting operations a posteriori identify atomic operations, but neglect composite operations, such as refactorings, which leads to cluttered difference reports. To tackle this limitation, we present an orthogonal extension of existing atomic operation detection approaches for detecting also composite operations. Our approach searches for occurrences of composite operations within a set of detected atomic operations in a post-processing manner. One major benefit is the reuse of specifications available for executing composite operations also for detecting applications of them. We evaluate the accuracy of the approach in a real-world case study and investigate the scalability of our implementation in an experiment. PMID:23471366

  7. A posteriori pointwise error estimates for the boundary element method

    SciTech Connect

    Paulino, G.H.; Gray, L.J.; Zarikian, V.

    1995-01-01

    This report presents a new approach for a posteriori pointwise error estimation in the boundary element method. The estimator relies upon the evaluation of hypersingular integral equations, and is therefore intrinsic to the boundary integral equation approach. This property allows some theoretical justification by mathematically correlating the exact and estimated errors. A methodology is developed for approximating the error on the boundary as well as in the interior of the domain. In the interior, error estimates for both the function and its derivatives (e.g. potential and interior gradients for potential problems, displacements and stresses for elasticity problems) are presented. Extensive computational experiments have been performed for the two dimensional Laplace equation on interior domains, employing Dirichlet and mixed boundary conditions. The results indicate that the error estimates successfully track the form of the exact error curve. Moreover, a reasonable estimate of the magnitude of the actual error is also obtained.

  8. Enabling Predictive Simulation and UQ of Complex Multiphysics PDE Systems by the Development of Goal-Oriented Variational Sensitivity Analysis and A Posteriori Error Estimation Methods

    SciTech Connect

    Ginting, Victor

    2014-03-15

    it was demonstrated that a posteriori analyses in general and in particular one that uses adjoint methods can accurately and efficiently compute numerical error estimates and sensitivity for critical Quantities of Interest (QoIs) that depend on a large number of parameters. Activities include: analysis and implementation of several time integration techniques for solving system of ODEs as typically obtained from spatial discretization of PDE systems; multirate integration methods for ordinary differential equations; formulation and analysis of an iterative multi-discretization Galerkin finite element method for multi-scale reaction-diffusion equations; investigation of an inexpensive postprocessing technique to estimate the error of finite element solution of the second-order quasi-linear elliptic problems measured in some global metrics; investigation of an application of the residual-based a posteriori error estimates to symmetric interior penalty discontinuous Galerkin method for solving a class of second order quasi-linear elliptic problems; a posteriori analysis of explicit time integrations for system of linear ordinary differential equations; derivation of accurate a posteriori goal oriented error estimates for a user-defined quantity of interest for two classes of first and second order IMEX schemes for advection-diffusion-reaction problems; Postprocessing finite element solution; and A Bayesian Framework for Uncertain Quantification of Porous Media Flows.

  9. A posteriori model validation for the temporal order of directed functional connectivity maps

    PubMed Central

    Beltz, Adriene M.; Molenaar, Peter C. M.

    2015-01-01

    A posteriori model validation for the temporal order of neural directed functional connectivity maps is rare. This is striking because models that require sequential independence among residuals are regularly implemented. The aim of the current study was (a) to apply to directed functional connectivity maps of functional magnetic resonance imaging data an a posteriori model validation procedure (i.e., white noise tests of one-step-ahead prediction errors combined with decision criteria for revising the maps based upon Lagrange Multiplier tests), and (b) to demonstrate how the procedure applies to single-subject simulated, single-subject task-related, and multi-subject resting state data. Directed functional connectivity was determined by the unified structural equation model family of approaches in order to map contemporaneous and first order lagged connections among brain regions at the group- and individual-levels while incorporating external input, then white noise tests were run. Findings revealed that the validation procedure successfully detected unmodeled sequential dependencies among residuals and recovered higher order (greater than one) simulated connections, and that the procedure can accommodate task-related input. Findings also revealed that lags greater than one were present in resting state data: With a group-level network that contained only contemporaneous and first order connections, 44% of subjects required second order, individual-level connections in order to obtain maps with white noise residuals. Results have broad methodological relevance (e.g., temporal validation is necessary after directed functional connectivity analyses because the presence of unmodeled higher order sequential dependencies may bias parameter estimates) and substantive implications (e.g., higher order lags may be common in resting state data). PMID:26379489

  10. A posteriori model validation for the temporal order of directed functional connectivity maps.

    PubMed

    Beltz, Adriene M; Molenaar, Peter C M

    2015-01-01

    A posteriori model validation for the temporal order of neural directed functional connectivity maps is rare. This is striking because models that require sequential independence among residuals are regularly implemented. The aim of the current study was (a) to apply to directed functional connectivity maps of functional magnetic resonance imaging data an a posteriori model validation procedure (i.e., white noise tests of one-step-ahead prediction errors combined with decision criteria for revising the maps based upon Lagrange Multiplier tests), and (b) to demonstrate how the procedure applies to single-subject simulated, single-subject task-related, and multi-subject resting state data. Directed functional connectivity was determined by the unified structural equation model family of approaches in order to map contemporaneous and first order lagged connections among brain regions at the group- and individual-levels while incorporating external input, then white noise tests were run. Findings revealed that the validation procedure successfully detected unmodeled sequential dependencies among residuals and recovered higher order (greater than one) simulated connections, and that the procedure can accommodate task-related input. Findings also revealed that lags greater than one were present in resting state data: With a group-level network that contained only contemporaneous and first order connections, 44% of subjects required second order, individual-level connections in order to obtain maps with white noise residuals. Results have broad methodological relevance (e.g., temporal validation is necessary after directed functional connectivity analyses because the presence of unmodeled higher order sequential dependencies may bias parameter estimates) and substantive implications (e.g., higher order lags may be common in resting state data). PMID:26379489

  11. A posteriori registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment

    PubMed Central

    Chibinski, Ana Cláudia; Coelho, Ulisses; Wambier, Letícia Stadler; Zedebski, Rosário de Arruda Moura; de Moraes, Mari Eli Leonelli; de Moraes, Luiz Cesar

    2016-01-01

    Purpose This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. Materials and Methods A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. Results The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. Conclusion A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment. PMID:27051635

  12. On the Least-Squares Fitting of Correlated Data: a Priorivs a PosterioriWeighting

    NASA Astrophysics Data System (ADS)

    Tellinghuisen, Joel

    1996-10-01

    One of the methods in common use for analyzing large data sets is a two-step procedure, in which subsets of the full data are first least-squares fitted to a preliminary set of parameters, and the latter are subsequently merged to yield the final parameters. The second step of this procedure is properly a correlated least-squares fit and requires the variance-covariance matrices from the first step to construct the weight matrix for the merge. There is, however, an ambiguity concerning the manner in which the first-step variance-covariance matrices are assessed, which leads to different statistical properties for the quantities determined in the merge. The issue is one ofa priorivsa posterioriassessment of weights, which is an application of what was originally calledinternalvsexternal consistencyby Birge [Phys. Rev.40,207-227 (1932)] and Deming ("Statistical Adjustment of Data." Dover, New York, 1964). In the present work the simplest case of a merge fit-that of an average as obtained from a global fit vs a two-step fit of partitioned data-is used to illustrate that only in the case of a priori weighting do the results have the usually expected and desired statistical properties: normal distributions for residuals,tdistributions for parameters assessed a posteriori, and χ2distributions for variances.

  13. A posteriori subcell limiting of the discontinuous Galerkin finite element method for hyperbolic conservation laws

    NASA Astrophysics Data System (ADS)

    Dumbser, Michael; Zanotti, Olindo; Loubère, Raphaël; Diot, Steven

    2014-12-01

    The purpose of this work is to propose a novel a posteriori finite volume subcell limiter technique for the Discontinuous Galerkin finite element method for nonlinear systems of hyperbolic conservation laws in multiple space dimensions that works well for arbitrary high order of accuracy in space and time and that does not destroy the natural subcell resolution properties of the DG method. High order time discretization is achieved via a one-step ADER approach that uses a local space-time discontinuous Galerkin predictor method to evolve the data locally in time within each cell. Our new limiting strategy is based on the so-called MOOD paradigm, which a posteriori verifies the validity of a discrete candidate solution against physical and numerical detection criteria after each time step. Here, we employ a relaxed discrete maximum principle in the sense of piecewise polynomials and the positivity of the numerical solution as detection criteria. Within the DG scheme on the main grid, the discrete solution is represented by piecewise polynomials of degree N. For those troubled cells that need limiting, our new limiter approach recomputes the discrete solution by scattering the DG polynomials at the previous time step onto a set of Ns=2N+1 finite volume subcells per space dimension. A robust but accurate ADER-WENO finite volume scheme then updates the subcell averages of the conservative variables within the detected troubled cells. The recomputed subcell averages are subsequently gathered back into high order cell-centered DG polynomials on the main grid via a subgrid reconstruction operator. The choice of Ns=2N+1 subcells is optimal since it allows to match the maximum admissible time step of the finite volume scheme on the subgrid with the maximum admissible time step of the DG scheme on the main grid, minimizing at the same time also the local truncation error of the subcell finite volume scheme. It furthermore provides an excellent subcell resolution of

  14. Rigorous A-Posteriori Assessment of Accuracy in EMG Decomposition

    PubMed Central

    McGill, Kevin C.; Marateb, Hamid R.

    2010-01-01

    If EMG decomposition is to be a useful tool for scientific investigation, it is essential to know that the results are accurate. Because of background noise, waveform variability, motor-unit action potential (MUAP) indistinguishability, and perplexing superpositions, accuracy assessment is not straightforward. This paper presents a rigorous statistical method for assessing decomposition accuracy based only on evidence from the signal itself. The method uses statistical decision theory in a Bayesian framework to integrate all the shape- and firing-time-related information in the signal to compute an objective a-posteriori measure of confidence in the accuracy of each discharge in the decomposition. The assessment is based on the estimated statistical properties of the MUAPs and noise and takes into account the relative likelihood of every other possible decomposition. The method was tested on 3 pairs of real EMG signals containing 4–7 active MUAP trains per signal that had been decomposed by a human expert. It rated 97% of the identified MUAP discharges as accurate to within ±0.5 ms with a confidence level of 99%, and detected 6 decomposition errors. Cross-checking between signal pairs verified all but 2 of these assertions. These results demonstrate that the approach is reliable and practical for real EMG signals. PMID:20639182

  15. A posteriori uncertainty quantification of PIV-based pressure data

    NASA Astrophysics Data System (ADS)

    Azijli, Iliass; Sciacchitano, Andrea; Ragni, Daniele; Palha, Artur; Dwight, Richard P.

    2016-05-01

    A methodology for a posteriori uncertainty quantification of pressure data retrieved from particle image velocimetry (PIV) is proposed. It relies upon the Bayesian framework, where the posterior distribution (probability distribution of the true velocity, given the PIV measurements) is obtained from the prior distribution (prior knowledge of properties of the velocity field, e.g., divergence-free) and the statistical model of PIV measurement uncertainty. Once the posterior covariance matrix of the velocity is known, it is propagated through the discretized Poisson equation for pressure. Numerical assessment of the proposed method on a steady Lamb-Oseen vortex shows excellent agreement with Monte Carlo simulations, while linear uncertainty propagation underestimates the uncertainty in the pressure by up to 30 %. The method is finally applied to an experimental test case of a turbulent boundary layer in air, obtained using time-resolved tomographic PIV. Simultaneously with the PIV measurements, microphone measurements were carried out at the wall. The pressure reconstructed from the tomographic PIV data is compared to the microphone measurements. Realizing that the uncertainty of the latter is significantly smaller than the PIV-based pressure, this allows us to obtain an estimate for the true error of the former. The comparison between true error and estimated uncertainty demonstrates the accuracy of the uncertainty estimates on the pressure. In addition, enforcing the divergence-free constraint is found to result in a significantly more accurate reconstructed pressure field. The estimated uncertainty confirms this result.

  16. A posteriori error estimates for finite volume approximations of elliptic equations on general surfaces

    SciTech Connect

    Ju, Lili; Tian, Li; Wang, Desheng

    2009-01-01

    In this paper, we present a residual-based a posteriori error estimate for the finite volume discretization of steady convection– diffusion–reaction equations defined on surfaces in R3, which are often implicitly represented as level sets of smooth functions. Reliability and efficiency of the proposed a posteriori error estimator are rigorously proved. Numerical experiments are also conducted to verify the theoretical results and demonstrate the robustness of the error estimator.

  17. A Posteriori Finite Element Bounds for Sensitivity Derivatives of Partial-Differential-Equation Outputs. Revised

    NASA Technical Reports Server (NTRS)

    Lewis, Robert Michael; Patera, Anthony T.; Peraire, Jaume

    1998-01-01

    We present a Neumann-subproblem a posteriori finite element procedure for the efficient and accurate calculation of rigorous, 'constant-free' upper and lower bounds for sensitivity derivatives of functionals of the solutions of partial differential equations. The design motivation for sensitivity derivative error control is discussed; the a posteriori finite element procedure is described; the asymptotic bounding properties and computational complexity of the method are summarized; and illustrative numerical results are presented.

  18. Preconditioned Alternating Projection Algorithms for Maximum a Posteriori ECT Reconstruction.

    PubMed

    Krol, Andrzej; Li, Si; Shen, Lixin; Xu, Yuesheng

    2012-11-01

    We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constrain involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the preconditioned alternating projection algorithm. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality. PMID:23271835

  19. Preconditioned Alternating Projection Algorithms for Maximum a Posteriori ECT Reconstruction

    PubMed Central

    Krol, Andrzej; Li, Si; Shen, Lixin; Xu, Yuesheng

    2012-01-01

    We propose a preconditioned alternating projection algorithm (PAPA) for solving the maximum a posteriori (MAP) emission computed tomography (ECT) reconstruction problem. Specifically, we formulate the reconstruction problem as a constrained convex optimization problem with the total variation (TV) regularization. We then characterize the solution of the constrained convex optimization problem and show that it satisfies a system of fixed-point equations defined in terms of two proximity operators raised from the convex functions that define the TV-norm and the constrain involved in the problem. The characterization (of the solution) via the proximity operators that define two projection operators naturally leads to an alternating projection algorithm for finding the solution. For efficient numerical computation, we introduce to the alternating projection algorithm a preconditioning matrix (the EM-preconditioner) for the dense system matrix involved in the optimization problem. We prove theoretically convergence of the preconditioned alternating projection algorithm. In numerical experiments, performance of our algorithms, with an appropriately selected preconditioning matrix, is compared with performance of the conventional MAP expectation-maximization (MAP-EM) algorithm with TV regularizer (EM-TV) and that of the recently developed nested EM-TV algorithm for ECT reconstruction. Based on the numerical experiments performed in this work, we observe that the alternating projection algorithm with the EM-preconditioner outperforms significantly the EM-TV in all aspects including the convergence speed, the noise in the reconstructed images and the image quality. It also outperforms the nested EM-TV in the convergence speed while providing comparable image quality. PMID:23271835

  20. Combined Uncertainty and A-Posteriori Error Bound Estimates for General CFD Calculations: Theory and Software Implementation

    NASA Technical Reports Server (NTRS)

    Barth, Timothy J.

    2014-01-01

    This workshop presentation discusses the design and implementation of numerical methods for the quantification of statistical uncertainty, including a-posteriori error bounds, for output quantities computed using CFD methods. Hydrodynamic realizations often contain numerical error arising from finite-dimensional approximation (e.g. numerical methods using grids, basis functions, particles) and statistical uncertainty arising from incomplete information and/or statistical characterization of model parameters and random fields. The first task at hand is to derive formal error bounds for statistics given realizations containing finite-dimensional numerical error [1]. The error in computed output statistics contains contributions from both realization error and the error resulting from the calculation of statistics integrals using a numerical method. A second task is to devise computable a-posteriori error bounds by numerically approximating all terms arising in the error bound estimates. For the same reason that CFD calculations including error bounds but omitting uncertainty modeling are only of limited value, CFD calculations including uncertainty modeling but omitting error bounds are only of limited value. To gain maximum value from CFD calculations, a general software package for uncertainty quantification with quantified error bounds has been developed at NASA. The package provides implementations for a suite of numerical methods used in uncertainty quantification: Dense tensorization basis methods [3] and a subscale recovery variant [1] for non-smooth data, Sparse tensorization methods[2] utilizing node-nested hierarchies, Sampling methods[4] for high-dimensional random variable spaces.

  1. A new approach to a maximum à posteriori-based kernel classification method.

    PubMed

    Nopriadi; Yamashita, Yukihiko

    2012-09-01

    This paper presents a new approach to a maximum a posteriori (MAP)-based classification, specifically, MAP-based kernel classification trained by linear programming (MAPLP). Unlike traditional MAP-based classifiers, MAPLP does not directly estimate a posterior probability for classification. Instead, it introduces a kernelized function to an objective function that behaves similarly to a MAP-based classifier. To evaluate the performance of MAPLP, a binary classification experiment was performed with 13 datasets. The results of this experiment are compared with those coming from conventional MAP-based kernel classifiers and also from other state-of-the-art classification methods. It shows that MAPLP performs promisingly against the other classification methods. It is argued that the proposed approach makes a significant contribution to MAP-based classification research; the approach widens the freedom to choose an objective function, it is not constrained to the strict sense Bayesian, and can be solved by linear programming. A substantial advantage of our proposed approach is that the objective function is undemanding, having only a single parameter. This simplicity, thus, allows for further research development in the future. PMID:22721808

  2. Maximum a posteriori classification of multifrequency, multilook, synthetic aperture radar intensity data

    NASA Technical Reports Server (NTRS)

    Rignot, E.; Chellappa, R.

    1993-01-01

    We present a maximum a posteriori (MAP) classifier for classifying multifrequency, multilook, single polarization SAR intensity data into regions or ensembles of pixels of homogeneous and similar radar backscatter characteristics. A model for the prior joint distribution of the multifrequency SAR intensity data is combined with a Markov random field for representing the interactions between region labels to obtain an expression for the posterior distribution of the region labels given the multifrequency SAR observations. The maximization of the posterior distribution yields Bayes's optimum region labeling or classification of the SAR data or its MAP estimate. The performance of the MAP classifier is evaluated by using computer-simulated multilook SAR intensity data as a function of the parameters in the classification process. Multilook SAR intensity data are shown to yield higher classification accuracies than one-look SAR complex amplitude data. The MAP classifier is extended to the case in which the radar backscatter from the remotely sensed surface varies within the SAR image because of incidence angle effects. The results obtained illustrate the practicality of the method for combining SAR intensity observations acquired at two different frequencies and for improving classification accuracy of SAR data.

  3. Estimation of parameters in linear structural relationships: Sensitivity to the choice of the ratio of error variances

    NASA Technical Reports Server (NTRS)

    Lakshminarayanan, M. Y.; Gunst, R. F.

    1984-01-01

    Maximum likelihood estimation of parameters in linear structural relationships under normality assumptions requires knowledge of one or more of the model parameters if no replication is available. The most common assumption added to the model definition is that the ratio of the error variances of the response and predictor variates is known. The use of asymptotic formulae for variances and mean squared errors as a function of sample size and the assumed value for the error variance ratio is investigated.

  4. Estimation of parameters in linear structural relationships Sensitivity to the choice of the ratio of error variances

    NASA Technical Reports Server (NTRS)

    Lakshminarayanan, M. Y.; Gunst, R. F.

    1984-01-01

    Maximum likelihood estimation of parameters in linear structural relationships under normality assumptions requires knowledge of one or more of the model parameters if no replication is available. The most common assumption added to the model definition is that the ratio of the error variances of the response and predictor variates is known. This paper investigates the use of asymptotic formulae for variances and mean squared errors as a function of sample size and the assumed value for the error variance ratio.

  5. Ontology based log content extraction engine for a posteriori security control.

    PubMed

    Azkia, Hanieh; Cuppens-Boulahia, Nora; Cuppens, Frédéric; Coatrieux, Gouenou

    2012-01-01

    In a posteriori access control, users are accountable for actions they performed and must provide evidence, when required by some legal authorities for instance, to prove that these actions were legitimate. Generally, log files contain the needed data to achieve this goal. This logged data can be recorded in several formats; we consider here IHE-ATNA (Integrating the healthcare enterprise-Audit Trail and Node Authentication) as log format. The difficulty lies in extracting useful information regardless of the log format. A posteriori access control frameworks often include a log filtering engine that provides this extraction function. In this paper we define and enforce this function by building an IHE-ATNA based ontology model, which we query using SPARQL, and show how the a posteriori security controls are made effective and easier based on this function. PMID:22874291

  6. A-Posteriori Error Estimation for Hyperbolic Conservation Laws with Constraint

    NASA Technical Reports Server (NTRS)

    Barth, Timothy

    2004-01-01

    This lecture considers a-posteriori error estimates for the numerical solution of conservation laws with time invariant constraints such as those arising in magnetohydrodynamics (MHD) and gravitational physics. Using standard duality arguments, a-posteriori error estimates for the discontinuous Galerkin finite element method are then presented for MHD with solenoidal constraint. From these estimates, a procedure for adaptive discretization is outlined. A taxonomy of Green's functions for the linearized MHD operator is given which characterizes the domain of dependence for pointwise errors. The extension to other constrained systems such as the Einstein equations of gravitational physics are then considered. Finally, future directions and open problems are discussed.

  7. A posteriori information effects on culpability judgments from a cross-cultural perspective.

    PubMed

    Wan, Wendy W N; Chiu, Chi-Yue; Luk, Chung-Leung

    2005-10-01

    A posteriori information about the moral attributes of the victim of a crime can affect an observer's judgment on the culpability of the actor of the crime so that negative moral attributes of the victim will lead to a lower judgment of culpability. The authors found this effect of a posteriori information among 118 American and 123 Chinese participants, but the underlying mechanisms were different between the two cultural groups. The Americans considered the psychological state of the actor during the crime, whereas the Chinese considered the morality of the actor during the crime. The authors discussed these results in light of the respondents' implicit theories of morality. PMID:16201675

  8. Application of the a posteriori granddaughter design to the Holstein genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An a posteriori granddaughter design was applied to determine haplotype effects for the Holstein genome. A total of 52 grandsire families, each with >=100 genotyped sons with genetic evaluations based on progeny tests, were analyzed for 33 traits (milk, fat, and protein yields; fat and protein perce...

  9. Weighted Maximum-a-Posteriori Estimation in Tests Composed of Dichotomous and Polytomous Items

    ERIC Educational Resources Information Center

    Sun, Shan-Shan; Tao, Jian; Chang, Hua-Hua; Shi, Ning-Zhong

    2012-01-01

    For mixed-type tests composed of dichotomous and polytomous items, polytomous items often yield more information than dichotomous items. To reflect the difference between the two types of items and to improve the precision of ability estimation, an adaptive weighted maximum-a-posteriori (WMAP) estimation is proposed. To evaluate the performance of…

  10. FORTRAN IV Program for Analysis of Covariance with A Priori or A Posteriori Mean Comparisons

    ERIC Educational Resources Information Center

    Fordyce, Michael W.

    1977-01-01

    A flexible Fortran program for computing a complete analysis of covariance is described. Requiring minimal core space, the program provides all group and overall summary statistics for the analysis, a test of homogeneity of regression, and all posttest mean comparisons for a priori or a posteriori testing. (Author/JKS)

  11. An Iterative Maximum a Posteriori Estimation of Proficiency Level to Detect Multiple Local Likelihood Maxima

    ERIC Educational Resources Information Center

    Magis, David; Raiche, Gilles

    2010-01-01

    In this article the authors focus on the issue of the nonuniqueness of the maximum likelihood (ML) estimator of proficiency level in item response theory (with special attention to logistic models). The usual maximum a posteriori (MAP) method offers a good alternative within that framework; however, this article highlights some drawbacks of its…

  12. Application of a posteriori error estimates for the steady Stokes-Brinkman equation in 2D

    NASA Astrophysics Data System (ADS)

    Hasal, Martin; Burda, Pavel

    2016-06-01

    The paper deals with the Stokes-Brinkman equation. We investigate a posteriori error estimates for the Stokes-Brinkman equation on two-dimensional polygonal domains. Special attention is paid to the value of the hydraulic conductivity coefficients. We present numerical results for an incompressible flow problem in a domain with corners.

  13. Nonmarket valuation of water quality in a rural transition economy in Turkey applying an a posteriori bid design

    NASA Astrophysics Data System (ADS)

    Bederli Tümay, Aylin; Brouwer, Roy

    2007-05-01

    In this paper, we investigate the economic benefits associated with public investments in wastewater treatment in one of the special protected areas along Turkey's touristic Mediterranean coast, the Köyceǧiz-Dalyan watershed. The benefits, measured in terms of boatable, fishable, swimmable and drinkable water quality, are estimated using a public survey format following the contingent valuation (CV) method. The study presented here is the first of its kind in Turkey. The study's main objective is to assess public perception, understanding, and valuation of improved wastewater treatment facilities in the two largest population centers in the watershed, facing the same water pollution problems as a result of lack of appropriate wastewater treatment. We test the validity and reliability of the application of the CV methodology to this specific environmental problem in a rural transition economy and evaluate the transferability of the results within the watershed. In order to facilitate willingness to pay (WTP) value elicitation we apply a novel dichotomous choice procedure where bid design takes place a posteriori instead of a priori. The statistical efficiency of different bid vectors is evaluated in terms of the estimated welfare measures' mean square errors using Monte Carlo simulation. The robustness of bid function specification is analyzed through average WTP and standard deviation estimated using parametric and nonparametric methods.

  14. Adaptive vibrational configuration interaction (A-VCI): A posteriori error estimation to efficiently compute anharmonic IR spectra.

    PubMed

    Garnier, Romain; Odunlami, Marc; Le Bris, Vincent; Bégué, Didier; Baraille, Isabelle; Coulaud, Olivier

    2016-05-28

    A new variational algorithm called adaptive vibrational configuration interaction (A-VCI) intended for the resolution of the vibrational Schrödinger equation was developed. The main advantage of this approach is to efficiently reduce the dimension of the active space generated into the configuration interaction (CI) process. Here, we assume that the Hamiltonian writes as a sum of products of operators. This adaptive algorithm was developed with the use of three correlated conditions, i.e., a suitable starting space, a criterion for convergence, and a procedure to expand the approximate space. The velocity of the algorithm was increased with the use of a posteriori error estimator (residue) to select the most relevant direction to increase the space. Two examples have been selected for benchmark. In the case of H2CO, we mainly study the performance of A-VCI algorithm: comparison with the variation-perturbation method, choice of the initial space, and residual contributions. For CH3CN, we compare the A-VCI results with a computed reference spectrum using the same potential energy surface and for an active space reduced by about 90%. PMID:27250295

  15. The Impact of Microphysical Schemes and Parameter Choices on MM5 Simulations of Warm-Season High Latitude Cloud and Precipitation Systems

    NASA Astrophysics Data System (ADS)

    Tilley, J. S.; Kramm, G.

    2002-12-01

    Recently, an increasing variety of schemes to represent cloud microphysical processes have been incorporated into mesoscale models. These schemes, which are usually "bulk" approaches to the microphysics in order to reduce computational cost, range from the rather simple to relatively complex in terms of the processes represented and their formulation. The schemes are based upon various theoretical, laboratory, field measurement, and cloud modeling studies that have appeared in the literature over the past forty years, studies that have focused almost exclusively on mid-latitude and tropical areas. While significant effort has been exercised to validate such microphysical schemes in mid-latitude and tropical environments, relatively little systematic work has been done to consider how such schemes would behave in high latitudes. This is particularly the case for sophisticated regional models such as the Penn State/NCAR MM5, where the microphysical scheme used must interact with other physical schemes in complex and nonlinear ways. This issue is an important one to consider from the perspectives of aviation weather, quantitative precipitation forecasts and radiative transfer, the latter having importance to regional and global climate modeling applications. In this paper we examine the impacts of different cloud microphysical treatments on MM5 simulations of warm season high latitude cloud and precipitation systems. We examine the sensitivity of simulated mesoscale cloud, precipitation and dynamic fields to (1) the choice of the various microphysical schemes routinely available with the MM5 system, and (2) modifications to key parameters (baseline ice nuclei concentrations, temperature thresholds and supersaturation thresholds) within individual parameterization schemes. Our experiments focus on a period during mid-June 1998 during the Surface Heat Budget of the Arctic (SHEBA) Experiment. Through the period there is considerable cloud property data available over the

  16. Maximum a posteriori estimation of crystallographic phases in X-ray diffraction tomography

    PubMed Central

    Gürsoy, Doĝa; Biçer, Tekin; Almer, Jonathan D.; Kettimuthu, Raj; Stock, Stuart R.; De Carlo, Francesco

    2015-01-01

    A maximum a posteriori approach is proposed for X-ray diffraction tomography for reconstructing three-dimensional spatial distribution of crystallographic phases and orientations of polycrystalline materials. The approach maximizes the a posteriori density which includes a Poisson log-likelihood and an a priori term that reinforces expected solution properties such as smoothness or local continuity. The reconstruction method is validated with experimental data acquired from a section of the spinous process of a porcine vertebra collected at the 1-ID-C beamline of the Advanced Photon Source, at Argonne National Laboratory. The reconstruction results show significant improvement in the reduction of aliasing and streaking artefacts, and improved robustness to noise and undersampling compared to conventional analytical inversion approaches. The approach has the potential to reduce data acquisition times, and significantly improve beamtime efficiency. PMID:25939627

  17. A Posteriori Error Estimation for Discontinuous Galerkin Approximations of Hyperbolic Systems

    NASA Technical Reports Server (NTRS)

    Larson, Mats G.; Barth, Timothy J.

    1999-01-01

    This article considers a posteriori error estimation of specified functionals for first-order systems of conservation laws discretized using the discontinuous Galerkin (DG) finite element method. Using duality techniques, we derive exact error representation formulas for both linear and nonlinear functionals given an associated bilinear or nonlinear variational form. Weighted residual approximations of the exact error representation formula are then proposed and numerically evaluated for Ringleb flow, an exact solution of the 2-D Euler equations.

  18. [Methods of a posteriori identification of food patterns in Brazilian children: a systematic review].

    PubMed

    Carvalho, Carolina Abreu de; Fonsêca, Poliana Cristina de Almeida; Nobre, Luciana Neri; Priore, Silvia Eloiza; Franceschini, Sylvia do Carmo Castro

    2016-01-01

    The objective of this study is to provide guidance for identifying dietary patterns using the a posteriori approach, and analyze the methodological aspects of the studies conducted in Brazil that identified the dietary patterns of children. Articles were selected from the Latin American and Caribbean Literature on Health Sciences, Scientific Electronic Library Online and Pubmed databases. The key words were: Dietary pattern; Food pattern; Principal Components Analysis; Factor analysis; Cluster analysis; Reduced rank regression. We included studies that identified dietary patterns of children using the a posteriori approach. Seven studies published between 2007 and 2014 were selected, six of which were cross-sectional and one cohort, Five studies used the food frequency questionnaire for dietary assessment; one used a 24-hour dietary recall and the other a food list. The method of exploratory approach used in most publications was principal components factor analysis, followed by cluster analysis. The sample size of the studies ranged from 232 to 4231, the values of the Kaiser-Meyer-Olkin test from 0.524 to 0.873, and Cronbach's alpha from 0.51 to 0.69. Few Brazilian studies identified dietary patterns of children using the a posteriori approach and principal components factor analysis was the technique most used. PMID:26816172

  19. Quantitative evaluation of efficiency of the methods for a posteriori filtration of the slip-rate time histories

    NASA Astrophysics Data System (ADS)

    Kristekova, M.; Galis, M.; Moczo, P.; Kristek, J.

    2012-04-01

    Simulated slip-rate time histories often are not free from spurious high-frequency oscillations. This is because the used spatial grid is not fine enough to properly discretize possibly broad-spectrum slip-rate and stress variations and the spatial breakdown zone of the propagating rupture. In order to reduce the oscillations some numerical modelers apply the artificial damping. An alternative way is the application of the adaptive smoothing algorithm (ASA, Galis et al. 2010). The other modelers, however, rely on the a posteriori filtration. If the oscillations do not affect (change) development and propagation of the rupture during simulations, it is possible to apply a posteriori filtration to reduce the oscillations. Often, however, the a posteriori filtration is a problematic trade-off between suppression of oscillations and distortion of a true slip rate. We present quantitative comparison of efficiency of several methods. We have analyzed slip-rate time histories simulated by the FEM-TSN method. Signals containing spurious high-frequency oscillations and signals after application of a posteriori filtering have been compared to the reference signal. The reference signal was created by application of a careful iterative and adjusted denoising of the slip rate simulated using the finest (technically possible) spatial grid. We performed extensive numerical simulations in order to test efficiency of a posteriori filtration for slip rates with different level and nature of spurious oscillations. We show that the time-frequency analysis and time-frequency misfit criteria (Kristekova et al. 2006, 2009) are suitable tools for evaluation of efficiency of a posteriori filtration methods and also clear indicators of possible distortions introduced by a posteriori filtration.

  20. Object detection and amplitude estimation based on maximum a posteriori reconstructions

    SciTech Connect

    Hanson, K.M.

    1990-01-01

    We report on the behavior of the linear maximum a posteriori (MAP) tomographic reconstruction technique as a function of the assumed rms noise {sigma}{sub n} in the measurements, which specifies the degree of confidence in the measurement data. The unconstrained MAP reconstructions are evaluated on the basis of the performance of two related tasks; object detection and amplitude estimation. It is found that the detectability of medium-sized discs remains constant up to relatively large {sigma}{sub n} before slowly diminishing. However, the amplitudes of the discs estimated from the MAP reconstructions increasingly deviate from their actual values as {sigma}{sub n} increases.

  1. A Posteriori Error Estimation for a Nodal Method in Neutron Transport Calculations

    SciTech Connect

    Azmy, Y.Y.; Buscaglia, G.C.; Zamonsky, O.M.

    1999-11-03

    An a posteriori error analysis of the spatial approximation is developed for the one-dimensional Arbitrarily High Order Transport-Nodal method. The error estimator preserves the order of convergence of the method when the mesh size tends to zero with respect to the L{sup 2} norm. It is based on the difference between two discrete solutions that are available from the analysis. The proposed estimator is decomposed into error indicators to allow the quantification of local errors. Some test problems with isotropic scattering are solved to compare the behavior of the true error to that of the estimated error.

  2. An a posteriori error estimator for shape optimization: application to EIT

    NASA Astrophysics Data System (ADS)

    Giacomini, M.; Pantz, O.; Trabelsi, K.

    2015-11-01

    In this paper we account for the numerical error introduced by the Finite Element approximation of the shape gradient to construct a guaranteed shape optimization method. We present a goal-oriented strategy inspired by the complementary energy principle to construct a constant-free, fully-computable a posteriori error estimator and to derive a certified upper bound of the error in the shape gradient. The resulting Adaptive Boundary Variation Algorithm (ABVA) is able to identify a genuine descent direction at each iteration and features a reliable stopping criterion for the optimization loop. Some preliminary numerical results for the inverse identification problem of Electrical Impedance Tomography are presented.

  3. Application of a posteriori granddaughter and modified granddaughter designs to determine Holstein haplotype effects.

    PubMed

    Weller, J I; VanRaden, P M; Wiggans, G R

    2013-08-01

    A posteriori and modified granddaughter designs were applied to determine haplotype effects for Holstein bulls and cows with BovineSNP50 [~50,000 single nucleotide polymorphisms (SNP); Illumina Inc., San Diego, CA] genotypes. The a posteriori granddaughter design was applied to 52 sire families, each with ≥100 genotyped sons with genetic evaluations based on progeny tests. For 33 traits (milk, fat, and protein yields; fat and protein percentages; somatic cell score; productive life; daughter pregnancy rate; heifer and cow conception rates; service-sire and daughter calving ease; service-sire and daughter stillbirth; 18 conformation traits; and net merit), the analysis was applied to the autosomal segment with the SNP with the greatest effect in the genomic evaluation of each trait. All traits except 2 had a within-family haplotype effect. The same design was applied with the genetic evaluations of sons corrected for SNP effects associated with chromosomes besides the one under analysis. The number of within-family contrasts was 166 without adjustment and 211 with adjustment. Of the 52 bulls analyzed, 36 had BovineHD (high density; Illumina Inc.) genotypes that were used to test for concordance between sire quantitative trait loci and SNP genotypes; complete concordance was not obtained for any effects. Of the 31 traits with effects from the a posteriori granddaughter design, 21 were analyzed with the modified granddaughter design. Only sires with a contrast for the a posteriori granddaughter design and ≥200 granddaughters with a record usable for genetic evaluation were included. Calving traits could not be analyzed because individual cow evaluations were not computed. Eight traits had within-family haplotype effects. With respect to milk and fat yields and fat percentage, the results on Bos taurus autosome (BTA) 14 corresponded to the hypothesis that a missense mutation in the diacylglycerol O-acyltransferase 1 (DGAT1) gene is the main causative mutation

  4. School Choice.

    ERIC Educational Resources Information Center

    The Progress of Education Reform 1999-2001, 1999

    1999-01-01

    This publication is the first in a series of reports that examine policy issues in education. It looks at the four major forms of school choice--charter schools, open enrollment, home schooling, and vouchers--and how they are changing the landscape of public education. School choice is one of the fastest-growing innovations in public education,…

  5. Quantitative optical coherence tomography by maximum a-posteriori estimation of signal intensity

    NASA Astrophysics Data System (ADS)

    Chan, Aaron C.; Kurokawa, Kazuhiro; Makita, Shuichi; Hong, Young-Joo; Miyazawa, Arata; Miura, Masahiro; Yasuno, Yoshiaki

    2016-03-01

    A maximum a-posteriori (MAP) estimator for signal amplitude of optical coherence tomography (OCT) is presented. This estimator provides an accurate and low bias estimation of the correct OCT signal amplitude even at very low signal-tonoise ratios. As a result, contrast improvement of retinal OCT images is demonstrated. In addition, this estimation method allows for an estimation reliability to be calculated. By combining the MAP estimator with a previously demonstrated attenuation imaging algorithm, we present attenuation coefficient images of the retina. From the reliability derived from the MAP image one can also determine which regions of the attenuation images are unreliable. From Jones matrix OCT data of the optic nerve head (ONH), we also demonstrate that combining MAP with polarization diversity (PD) OCT images can generate intensity images with fewer birefringence artifacts, resulting in better attenuation images. Analysis of the MAP intensity images shows higher image SNR than averaging.

  6. A posteriori correction of camera characteristics from large image data sets.

    PubMed

    Afanasyev, Pavel; Ravelli, Raimond B G; Matadeen, Rishi; De Carlo, Sacha; van Duinen, Gijs; Alewijnse, Bart; Peters, Peter J; Abrahams, Jan-Pieter; Portugal, Rodrigo V; Schatz, Michael; van Heel, Marin

    2015-01-01

    Large datasets are emerging in many fields of image processing including: electron microscopy, light microscopy, medical X-ray imaging, astronomy, etc. Novel computer-controlled instrumentation facilitates the collection of very large datasets containing thousands of individual digital images. In single-particle cryogenic electron microscopy ("cryo-EM"), for example, large datasets are required for achieving quasi-atomic resolution structures of biological complexes. Based on the collected data alone, large datasets allow us to precisely determine the statistical properties of the imaging sensor on a pixel-by-pixel basis, independent of any "a priori" normalization routinely applied to the raw image data during collection ("flat field correction"). Our straightforward "a posteriori" correction yields clean linear images as can be verified by Fourier Ring Correlation (FRC), illustrating the statistical independence of the corrected images over all spatial frequencies. The image sensor characteristics can also be measured continuously and used for correcting upcoming images. PMID:26068909

  7. Maximum a posteriori video super-resolution using a new multichannel image prior.

    PubMed

    Belekos, Stefanos P; Galatsanos, Nikolaos P; Katsaggelos, Aggelos K

    2010-06-01

    Super-resolution (SR) is the term used to define the process of estimating a high-resolution (HR) image or a set of HR images from a set of low-resolution (LR) observations. In this paper we propose a class of SR algorithms based on the maximum a posteriori (MAP) framework. These algorithms utilize a new multichannel image prior model, along with the state-of-the-art single channel image prior and observation models. A hierarchical (two-level) Gaussian nonstationary version of the multichannel prior is also defined and utilized within the same framework. Numerical experiments comparing the proposed algorithms among themselves and with other algorithms in the literature, demonstrate the advantages of the adopted multichannel approach. PMID:20129860

  8. Conjugate quasilinear Dirichlet and Neumann problems and a posteriori error bounds

    NASA Technical Reports Server (NTRS)

    Lavery, J. E.

    1976-01-01

    Quasilinear Dirichlet and Neumann problems on a rectangle D with boundary D prime are considered. Using these concepts, conjugate problems, that is, a pair of one Dirichlet and one Neumann problem, the minima of the energies of which add to zero, are introduced. From the concept of conjugate problems, two-sided bounds for the energy of the exact solution of any given Dirichlet or Neumann problem are constructed. These two-sided bounds for the energy at the exact solution are in turn used to obtain a posteriori error bounds for the norm of the difference of the approximate and exact solutions of the problem. These bounds do not involve the unknown exact solution and are easily constructed numerically.

  9. Real-time maximum a-posteriori image reconstruction for fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Jabbar, Anwar A.; Dilipkumar, Shilpa; C K, Rasmi; Rajan, K.; Mondal, Partha P.

    2015-08-01

    Rapid reconstruction of multidimensional image is crucial for enabling real-time 3D fluorescence imaging. This becomes a key factor for imaging rapidly occurring events in the cellular environment. To facilitate real-time imaging, we have developed a graphics processing unit (GPU) based real-time maximum a-posteriori (MAP) image reconstruction system. The parallel processing capability of GPU device that consists of a large number of tiny processing cores and the adaptability of image reconstruction algorithm to parallel processing (that employ multiple independent computing modules called threads) results in high temporal resolution. Moreover, the proposed quadratic potential based MAP algorithm effectively deconvolves the images as well as suppresses the noise. The multi-node multi-threaded GPU and the Compute Unified Device Architecture (CUDA) efficiently execute the iterative image reconstruction algorithm that is ≈200-fold faster (for large dataset) when compared to existing CPU based systems.

  10. Machine learning source separation using maximum a posteriori nonnegative matrix factorization.

    PubMed

    Gao, Bin; Woo, Wai Lok; Ling, Bingo W-K

    2014-07-01

    A novel unsupervised machine learning algorithm for single channel source separation is presented. The proposed method is based on nonnegative matrix factorization, which is optimized under the framework of maximum a posteriori probability and Itakura-Saito divergence. The method enables a generalized criterion for variable sparseness to be imposed onto the solution and prior information to be explicitly incorporated through the basis vectors. In addition, the method is scale invariant where both low and high energy components of a signal are treated with equal importance. The proposed algorithm is a more complete and efficient approach for matrix factorization of signals that exhibit temporal dependency of the frequency patterns. Experimental tests have been conducted and compared with other algorithms to verify the efficiency of the proposed method. PMID:24217003

  11. Edge-based a posteriori error estimators for generation of d-dimensional quasi-optimal meshes

    SciTech Connect

    Lipnikov, Konstantin; Agouzal, Abdellatif; Vassilevski, Yuri

    2009-01-01

    We present a new method of metric recovery for minimization of L{sub p}-norms of the interpolation error or its gradient. The method uses edge-based a posteriori error estimates. The method is analyzed for conformal simplicial meshes in spaces of arbitrary dimension d.

  12. FORTRAN IV Program for One-Way Analysis of Variance with A Priori or A Posteriori Mean Comparisons

    ERIC Educational Resources Information Center

    Fordyce, Michael W.

    1977-01-01

    A flexible Fortran program for computing one way analysis of variance is described. Requiring minimal core space, the program provides a variety of useful group statistics, all summary statistics for the analysis, and all mean comparisons for a priori or a posteriori testing. (Author/JKS)

  13. Volcanic eruption source parameters from active and passive microwave sensors

    NASA Astrophysics Data System (ADS)

    Montopoli, Mario; Marzano, Frank S.; Cimini, Domenico; Mereu, Luigi

    2016-04-01

    It is well known, in the volcanology community, that precise information of the source parameters characterising an eruption are of predominant interest for the initialization of the Volcanic Transport and Dispersion Models (VTDM). Source parameters of main interest would be the top altitude of the volcanic plume, the flux of the mass ejected at the emission source, which is strictly related to the cloud top altitude, the distribution of volcanic mass concentration along the vertical column as well as the duration of the eruption and the erupted volume. Usually, the combination of a-posteriori field and numerical studies allow constraining the eruption source parameters for a given volcanic event thus making possible the forecast of ash dispersion and deposition from future volcanic eruptions. So far, remote sensors working at visible and infrared channels (cameras and radiometers) have been mainly used to detect, track and provide estimates of the concentration content and the prevailing size of the particles propagating within the ash clouds up to several thousand of kilometres far from the source as well as track back, a-posteriori, the accuracy of the VATDM outputs thus testing the initial choice made for the source parameters. Acoustic wave (infrasound) and microwave fixed scan radar (voldorad) were also used to infer source parameters. In this work we want to put our attention on the role of sensors operating at microwave wavelengths as complementary tools for the real time estimations of source parameters. Microwaves can benefit of the operability during night and day and a relatively negligible sensitivity to the presence of clouds (non precipitating weather clouds) at the cost of a limited coverage and larger spatial resolution when compared with infrared sensors. Thanks to the aforementioned advantages, the products from microwaves sensors are expected to be sensible mostly to the whole path traversed along the tephra cloud making microwaves particularly

  14. A Maximum A Posteriori Probability and Time-Varying Approach for Inferring Gene Regulatory Networks from Time Course Gene Microarray Data.

    PubMed

    Chan, Shing-Chow; Zhang, Li; Wu, Ho-Chun; Tsui, Kai-Man

    2015-01-01

    Unlike most conventional techniques with static model assumption, this paper aims to estimate the time-varying model parameters and identify significant genes involved at different timepoints from time course gene microarray data. We first formulate the parameter identification problem as a new maximum a posteriori probability estimation problem so that prior information can be incorporated as regularization terms to reduce the large estimation variance of the high dimensional estimation problem. Under this framework, sparsity and temporal consistency of the model parameters are imposed using L1-regularization and novel continuity constraints, respectively. The resulting problem is solved using the L-BFGS method with the initial guess obtained from the partial least squares method. A novel forward validation measure is also proposed for the selection of regularization parameters, based on both forward and current prediction errors. The proposed method is evaluated using a synthetic benchmark testing data and a publicly available yeast Saccharomyces cerevisiae cell cycle microarray data. For the latter particularly, a number of significant genes identified at different timepoints are found to be biological significant according to previous findings in biological experiments. These suggest that the proposed approach may serve as a valuable tool for inferring time-varying gene regulatory networks in biological studies. PMID:26357083

  15. Choice Matters.

    ERIC Educational Resources Information Center

    Hicks, Darcy

    2001-01-01

    Describes how the author allows the children to make choices about their art and writing, enabling them to make connections between their own lives and work. Suggests that educators need to provide doorways to the things that give students ideas: books, music, objects, pictures, smells, sounds, and textures. (SG)

  16. An a-posteriori finite element error estimator for adaptive grid computation of viscous incompressible flows

    NASA Astrophysics Data System (ADS)

    Wu, Heng

    2000-10-01

    In this thesis, an a-posteriori error estimator is presented and employed for solving viscous incompressible flow problems. In an effort to detect local flow features, such as vortices and separation, and to resolve flow details precisely, a velocity angle error estimator e theta which is based on the spatial derivative of velocity direction fields is designed and constructed. The a-posteriori error estimator corresponds to the antisymmetric part of the deformation-rate-tensor, and it is sensitive to the second derivative of the velocity angle field. Rationality discussions reveal that the velocity angle error estimator is a curvature error estimator, and its value reflects the accuracy of streamline curves. It is also found that the velocity angle error estimator contains the nonlinear convective term of the Navier-Stokes equations, and it identifies and computes the direction difference when the convective acceleration direction and the flow velocity direction have a disparity. Through benchmarking computed variables with the analytic solution of Kovasznay flow or the finest grid of cavity flow, it is demonstrated that the velocity angle error estimator has a better performance than the strain error estimator. The benchmarking work also shows that the computed profile obtained by using etheta can achieve the best matching outcome with the true theta field, and that it is asymptotic to the true theta variation field, with a promise of fewer unknowns. Unstructured grids are adapted by employing local cell division as well as unrefinement of transition cells. Using element class and node class can efficiently construct a hierarchical data structure which provides cell and node inter-reference at each adaptive level. Employing element pointers and node pointers can dynamically maintain the connection of adjacent elements and adjacent nodes, and thus avoids time-consuming search processes. The adaptive scheme is applied to viscous incompressible flow at different

  17. Finite Element A Posteriori Error Estimation for Heat Conduction. Degree awarded by George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Lang, Christapher G.; Bey, Kim S. (Technical Monitor)

    2002-01-01

    This research investigates residual-based a posteriori error estimates for finite element approximations of heat conduction in single-layer and multi-layered materials. The finite element approximation, based upon hierarchical modelling combined with p-version finite elements, is described with specific application to a two-dimensional, steady state, heat-conduction problem. Element error indicators are determined by solving an element equation for the error with the element residual as a source, and a global error estimate in the energy norm is computed by collecting the element contributions. Numerical results of the performance of the error estimate are presented by comparisons to the actual error. Two methods are discussed and compared for approximating the element boundary flux. The equilibrated flux method provides more accurate results for estimating the error than the average flux method. The error estimation is applied to multi-layered materials with a modification to the equilibrated flux method to approximate the discontinuous flux along a boundary at the material interfaces. A directional error indicator is developed which distinguishes between the hierarchical modeling error and the finite element error. Numerical results are presented for single-layered materials which show that the directional indicators accurately determine which contribution to the total error dominates.

  18. On Evaluation of Recharge Model Uncertainty: a Priori and a Posteriori

    SciTech Connect

    Ming Ye; Karl Pohlmann; Jenny Chapman; David Shafer

    2006-01-30

    Hydrologic environments are open and complex, rendering them prone to multiple interpretations and mathematical descriptions. Hydrologic analyses typically rely on a single conceptual-mathematical model, which ignores conceptual model uncertainty and may result in bias in predictions and under-estimation of predictive uncertainty. This study is to assess conceptual model uncertainty residing in five recharge models developed to date by different researchers based on different theories for Nevada and Death Valley area, CA. A recently developed statistical method, Maximum Likelihood Bayesian Model Averaging (MLBMA), is utilized for this analysis. In a Bayesian framework, the recharge model uncertainty is assessed, a priori, using expert judgments collected through an expert elicitation in the form of prior probabilities of the models. The uncertainty is then evaluated, a posteriori, by updating the prior probabilities to estimate posterior model probability. The updating is conducted through maximum likelihood inverse modeling by calibrating the Death Valley Regional Flow System (DVRFS) model corresponding to each recharge model against observations of head and flow. Calibration results of DVRFS for the five recharge models are used to estimate three information criteria (AIC, BIC, and KIC) used to rank and discriminate these models. Posterior probabilities of the five recharge models, evaluated using KIC, are used as weights to average head predictions, which gives posterior mean and variance. The posterior quantities incorporate both parametric and conceptual model uncertainties.

  19. Resolution enhancement of hyperspectral imagery using maximum a posteriori estimation with a stochastic mixing model

    NASA Astrophysics Data System (ADS)

    Eismann, Michael Theodore

    A maximum a posteriori estimation method is developed and tested for enhancing the spatial resolution of hyperspectral imagery using higher resolution, coincident, panchromatic or multispectral imagery. The approach incorporates a stochastic mixing model of the underlying spectral scene content to develop a cost function that simultaneously optimizes the estimated hyperspectral scene relative to the observed hyperspectral and auxiliary imagery, as well as the local statistics of the spectral mixing model. The incorporation of the stochastic mixing model is found to be the key ingredient to reconstructing sub-pixel spectral information. It provides the necessary constraints for establishing a well-conditioned linear system of equations that can be solved for the high resolution image estimate. The research presented includes a mathematical formulation of the estimation approach and stochastic mixing model, as well as enhancement results for a variety of both synthetic and actual imagery. Both direct and iterative solution methodologies are developed, the latter being necessary to effectively treat imagery with arbitrarily specified spectral and spatial response functions. The performance of the method is qualitatively and quantitatively compared to that of previously developed resolution enhancement approaches. It is found that this novel approach is generally able to reconstruct sub-pixel information in several principal components of the high resolution hyperspectral image estimate. In contrast, the enhancement for conventional methods such as principal component substitution and least-squares estimation is mostly limited to the first principal component.

  20. Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

    DOE PAGESBeta

    Jakeman, J. D.; Wildey, T.

    2015-01-01

    In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity. We show that utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this papermore » we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.« less

  1. Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

    SciTech Connect

    Jakeman, J. D.; Wildey, T.

    2015-01-01

    In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity. We show that utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this paper we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.

  2. The choice of the mathematical method for prediction of electrochemical accumulator parameters value in power installations of space-rocket objects

    NASA Astrophysics Data System (ADS)

    Bezruchko, K. V.; Davidov, A. O.; Katorgina, J. G.; Logvin, V. M.; Kharchenko, A. A.

    2013-11-01

    The review and analysis of several mathematical methods for prediction of electrochemical accumulator parameters are provided in the article: according to the mathematical expectation, the latest entry, a statistical prediction, Box-Jenkins model, decomposition Volta, ARMA, ARIMA and Kalman filter. The results of these methods for prediction of the electrochemical battery 22НКГ-4CK characteristics which is a part of spacecraft power plant of the “Mikrosputnik” type are given. Possible usage of these methods for long prediction of electrochemical accumulator characteristics on space-rocket objects power plants is showed.

  3. Hard choices.

    PubMed

    Furedi, A

    1999-01-01

    The cultural discourse that frames the abortion debate has changed and become more complex over the years. To date, concerns about the need to defend the choice have shifted to moral and ethical issues surrounding abortion. The right of women to abortion can be situated in the context of ethical principles, which are basic to what we hold valuable in the modern society. The ethical principle of "procreative autonomy", the right of humans to control their own role in procreation has an unusually significant place in modern political culture in which human dignity was an important feature. Central to human dignity was the principle that "people possess the moral right and responsibility to answer the basic questions about the value and meaning of their own lives." Another crucial issue is the need to defend the "bodily autonomy" of women. Forcing women to support the fetus against her will flies against such principles as the need for voluntary consent to medical treatment. These arguments do not suggest for a moral indifference towards abortion choices, but as Ronald Dworkin argues, "tolerance is a cost we must pay for our adventure in liberty." PMID:12178906

  4. A Posteriori Study of a DNS Database Describing Super critical Binary-Species Mixing

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Taskinoglu, Ezgi

    2012-01-01

    Currently, the modeling of supercritical-pressure flows through Large Eddy Simulation (LES) uses models derived for atmospheric-pressure flows. Those atmospheric-pressure flows do not exhibit the particularities of high densitygradient magnitude features observed both in experiments and simulations of supercritical-pressure flows in the case of two species mixing. To assess whether the current LES modeling is appropriate and if found not appropriate to propose higher-fidelity models, a LES a posteriori study has been conducted for a mixing layer that initially contains different species in the lower and upper streams, and where the initial pressure is larger than the critical pressure of either species. An initially-imposed vorticity perturbation promotes roll-up and a double pairing of four initial span-wise vortices into an ultimate vortex that reaches a transitional state. The LES equations consist of the differential conservation equations coupled with a real-gas equation of state, and the equation set uses transport properties depending on the thermodynamic variables. Unlike all LES models to date, the differential equations contain, additional to the subgrid scale (SGS) fluxes, a new SGS term that is a pressure correction in the momentum equation. This additional term results from filtering of Direct Numerical Simulation (DNS) equations, and represents the gradient of the difference between the filtered pressure and the pressure computed from the filtered flow field. A previous a priori analysis, using a DNS database for the same configuration, found this term to be of leading order in the momentum equation, a fact traced to the existence of high-densitygradient magnitude regions that populated the entire flow; in the study, models were proposed for the SGS fluxes as well as this new term. In the present study, the previously proposed constantcoefficient SGS-flux models of the a priori investigation are tested a posteriori in LES, devoid of or including, the

  5. Relevance of the choice of spark plasma sintering parameters in obtaining a suitable microstructure for iodine-bearing apatite designed for the conditioning of I-129

    NASA Astrophysics Data System (ADS)

    Campayo, L.; Le Gallet, S.; Perret, D.; Courtois, E.; Cau Dit Coumes, C.; Grin, Yu.; Bernard, F.

    2015-02-01

    The high chemical durability of iodine-bearing apatite phases makes them potentially attractive for immobilizing radioactive iodine. Reactive spark plasma sintering provides a dense ceramic as a wasteform. A design-of-experiments (DOE) approach was adopted to identify the main process/material parameters and their first order interactions in order to specify experimental conditions guaranteeing complete reaction, relative density of the wasteform exceeding 92% and the largest possible grain size. For a disposal of the wasteform in a deep geological repository, these characteristics allow minimization of the iodine release by contact with groundwater. It was found that sintering at a temperature of 450 °C with an initial specific surface area of 3.3 m2 g-1 for the powder reactants is sufficient in itself to achieve the targeted characteristics of the wasteform. However, this relies on a liquid sintering regime the efficiency of which can be limited by the lead iodide initial content in the mix as well as by its particle size.

  6. Choice-Based Conjoint Analysis: Classification vs. Discrete Choice Models

    NASA Astrophysics Data System (ADS)

    Giesen, Joachim; Mueller, Klaus; Taneva, Bilyana; Zolliker, Peter

    Conjoint analysis is a family of techniques that originated in psychology and later became popular in market research. The main objective of conjoint analysis is to measure an individual's or a population's preferences on a class of options that can be described by parameters and their levels. We consider preference data obtained in choice-based conjoint analysis studies, where one observes test persons' choices on small subsets of the options. There are many ways to analyze choice-based conjoint analysis data. Here we discuss the intuition behind a classification based approach, and compare this approach to one based on statistical assumptions (discrete choice models) and to a regression approach. Our comparison on real and synthetic data indicates that the classification approach outperforms the discrete choice models.

  7. Effect of parameter choice in root water uptake models - the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake

    NASA Astrophysics Data System (ADS)

    Bechmann, M.; Schneider, C.; Carminati, A.; Vetterlein, D.; Attinger, S.; Hildebrandt, A.

    2014-10-01

    Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However, they suffer from a lack of information on important parameters, particularly on the spatial distribution of root axial and radial conductivities, which vary greatly along a root system. In this paper we explore how the arrangement of those root hydraulic properties and branching within the root system affects modelled uptake dynamics, xylem water potential and the efficiency of root water uptake. We first apply a simple model to illustrate the mechanisms at the scale of single roots. By using two efficiency indices based on (i) the collar xylem potential ("effort") and (ii) the integral amount of unstressed root water uptake ("water yield"), we show that an optimal root length emerges, depending on the ratio between roots axial and radial conductivity. Young roots with high capacity for radial uptake are only efficient when they are short. Branching, in combination with mature transport roots, enables soil exploration and substantially increases active young root length at low collar potentials. Second, we investigate how this shapes uptake dynamics at the plant scale using a comprehensive three-dimensional root water uptake model. Plant-scale dynamics, such as the average uptake depth of entire root systems, were only minimally influenced by the hydraulic parameterization. However, other factors such as hydraulic redistribution, collar potential, internal redistribution patterns and instantaneous uptake depth depended strongly on the arrangement on the arrangement of root hydraulic properties. Root systems were most efficient when assembled of different root types, allowing for separation of root function in uptake (numerous short apical young roots) and transport (longer mature roots). Modelling results became similar when this heterogeneity was accounted for to some degree (i.e. if the root systems contained between

  8. Application of the a posteriori granddaughter design to the Holstein genome.

    PubMed

    Weller, J I; Cole, J B; Vanraden, P M; Wiggans, G R

    2014-04-01

    An a posteriori granddaughter design was applied to estimate quantitative trait loci genotypes of sires with many sons in the US Holstein population. The results of this analysis can be used to determine concordance between specific polymorphisms and segregating quantitative trait loci. Determination of the actual polymorphisms responsible for observed genetic variation should increase the accuracy of genomic evaluations and rates of genetic gain. A total of 52 grandsire families, each with ⩾100 genotyped sons with genetic evaluations based on progeny tests, were analyzed for 33 traits (milk, fat and protein yields; fat and protein percentages; somatic cell score (SCS); productive life; daughter pregnancy rate; heifer and cow conception rates; service-sire and daughter calving ease; service-sire and daughter stillbirth rates; 18 conformation traits; and net merit). Of 617 haplotype segments spanning the entire bovine genome and each including ~5×106 bp, 5 cM and 50 genes, 608 autosomal segments were analyzed. A total of 19 335 unique haplotypes were found among the 52 grandsires. There were a total of 133 chromosomal segment-by-trait combinations, for which the nominal probability of significance for the haplotype effect was <10-8, which corresponds to genome-wide significance of <10-4. The number of chromosomal regions that met this criterion by trait ranged from one for rear legs (rear view) to seven for net merit. For each of the putative quantitative trait loci, at least one grandsire family had a within-family contrast with a t-value of >3. Confidence intervals (CIs) were estimated by the nonparametric bootstrap for the largest effect for each of nine traits. The bootstrap distribution generated by 100 samples was bimodal only for net merit, which had the widest 90% CI (eight haplotype segments). This may be due to the fact that net merit is a composite trait. For all other chromosomes, the CI spanned less than a third of the chromosome. The narrowest CI (a

  9. Blind deconvolution of images with model discrepancies using maximum a posteriori estimation with heavy-tailed priors

    NASA Astrophysics Data System (ADS)

    Kotera, Jan; Å roubek, Filip

    2015-02-01

    Single image blind deconvolution aims to estimate the unknown blur from a single observed blurred image and recover the original sharp image. Such task is severely ill-posed and typical approaches involve some heuristic or other steps without clear mathematical explanation to arrive at an acceptable solution. We show that a straight- forward maximum a posteriori estimation incorporating sparse priors and mechanism to deal with boundary artifacts, combined with an efficient numerical method can produce results which compete with or outperform much more complicated state-of-the-art methods. Our method is naturally extended to deal with overexposure in low-light photography, where linear blurring model is violated.

  10. Combined Uncertainty and A-Posteriori Error Bound Estimates for CFD Calculations: Theory and Implementation

    NASA Technical Reports Server (NTRS)

    Barth, Timothy J.

    2014-01-01

    Simulation codes often utilize finite-dimensional approximation resulting in numerical error. Some examples include, numerical methods utilizing grids and finite-dimensional basis functions, particle methods using a finite number of particles. These same simulation codes also often contain sources of uncertainty, for example, uncertain parameters and fields associated with the imposition of initial and boundary data,uncertain physical model parameters such as chemical reaction rates, mixture model parameters, material property parameters, etc.

  11. School Choice vs. School Choice. Policy Backgrounder.

    ERIC Educational Resources Information Center

    Goodman, John C.; Moore, Matt

    This paper recommends replacing the existing U.S. school choice system, which relies on the housing market to ration educational opportunity, with one that creates a level playing field upon which schools compete for students, and students and their parents exercise choice. Section 1 describes the current school choice system, which works well for…

  12. A Novel Gibbs Maximum A Posteriori (GMAP) Approach on Bayesian Nonlinear Mixed-Effects Population Pharmacokinetics (PK) Models

    PubMed Central

    Kim, Seongho; Hall, Stephen D.; Li, Lang

    2009-01-01

    In this paper, various Bayesian Monte Carlo Markov Chain (MCMC) methods and the proposed algorithm, Gibbs maximum a posteriori (GMAP) algorithm, are compared for implementing the nonlinear mixed-effects model in pharmacokinetics (PK) studies. An intravenous two-compartmental PK model is adopted to fit the PK data from the midazolam (MDZ) studies, which recruited 24 individuals with 9 different time points per subject. The three-stage hierarchical nonlinear mixed model is constructed. Data analysis and model performance comparisons show that GMAP converges the fastest, and provides reliable results. At the mean time, data augmentation (DA) methods are used for the Random-walk Metropolis method. Data analysis shows that the speed of the convergence of Random-walk Metropolis can be improved by DA, but all of them are not as fast as GMAP. The performance of GMAP and various MCMC algorithms are compared through Midazolam data analysis and simulation. PMID:20183435

  13. A posteriori error estimates for continuous/discontinuous Galerkin approximations of the Kirchhoff-Love buckling problem

    NASA Astrophysics Data System (ADS)

    Hansbo, Peter; Larson, Mats G.

    2015-11-01

    Second order buckling theory involves a one-way coupled coupled problem where the stress tensor from a plane stress problem appears in an eigenvalue problem for the fourth order Kirchhoff plate. In this paper we present an a posteriori error estimate for the critical buckling load and mode corresponding to the smallest eigenvalue and associated eigenvector. A particular feature of the analysis is that we take the effect of approximate computation of the stress tensor and also provide an error indicator for the plane stress problem. The Kirchhoff plate is discretized using a continuous/discontinuous finite element method based on standard continuous piecewise polynomial finite element spaces. The same finite element spaces can be used to solve the plane stress problem.

  14. Reliable and efficient a posteriori error estimation for adaptive IGA boundary element methods for weakly-singular integral equations

    PubMed Central

    Feischl, Michael; Gantner, Gregor; Praetorius, Dirk

    2015-01-01

    We consider the Galerkin boundary element method (BEM) for weakly-singular integral equations of the first-kind in 2D. We analyze some residual-type a posteriori error estimator which provides a lower as well as an upper bound for the unknown Galerkin BEM error. The required assumptions are weak and allow for piecewise smooth parametrizations of the boundary, local mesh-refinement, and related standard piecewise polynomials as well as NURBS. In particular, our analysis gives a first contribution to adaptive BEM in the frame of isogeometric analysis (IGABEM), for which we formulate an adaptive algorithm which steers the local mesh-refinement and the multiplicity of the knots. Numerical experiments underline the theoretical findings and show that the proposed adaptive strategy leads to optimal convergence. PMID:26085698

  15. Choice in Public Education.

    ERIC Educational Resources Information Center

    Young, Timothy W.; Clinchy, Evans

    There has been much recent debate in both educational and political circles about the utility of choice as a means of improving the educational system. This book argues that any discussion of choice must address choice in public schools. The book is organized into seven chapters. Chapter 1 provides an overview of choice in public education,…

  16. Making Smart Food Choices

    MedlinePlus

    ... turn JavaScript on. Feature: Healthy Aging Making Smart Food Choices Past Issues / Winter 2015 Table of Contents ... NIH www.nia.nih.gov/Go4Life Making Smart Food Choices To maintain a healthy weight, balance the ...

  17. Making Smart Food Choices

    MedlinePlus

    ... Go4Life Get Free Stuff Be a Partner Making Smart Food Choices Regular physical activity and a healthy ... through physical activity. Download the Tip Sheet Making Smart Food Choices (PDF, 488.99 KB) You Might ...

  18. Savage Misunderstandings about Choice.

    ERIC Educational Resources Information Center

    Gura, Mark

    1993-01-01

    Although Jonathan Kozol is well-informed about choice program imperfections, schools of choice are superior to traditional schools. In places like East Harlem, school choice is helping transform youngsters from captive, disenfranchised malcontents to true students involved in their education. The challenge is to make every district school worthy…

  19. Doing School Choice Right

    ERIC Educational Resources Information Center

    Hill, Paul T.

    2005-01-01

    School choice is growing, due to growth of charter schools, private voucher programs, and No Child Left Behind requirements that school districts offer options to children in low-performing schools. Growth can bring dangers if choice is implemented carelessly. Recent research on choice shows that program design and implementation matter: the…

  20. The impact of the choice of radiative transfer model and inversion method on the OSIRIS ozone and nitrogen dioxide retrievals

    NASA Astrophysics Data System (ADS)

    Haley, Craig; McLinden, Chris; Sioris, Christopher; Brohede, Samuel

    Key to the retrieval of stratospheric minor species information from limb-scatter measurements are the selections of a radiative transfer model (RTM) and inversion method (solver). Here we assess the impact of choice of RTM and solver on the retrievals of stratospheric ozone and nitrogen dioxide from the OSIRIS instrument using the ‘Ozone Triplet' and Differential Optical Absorption Spectroscopy (DOAS) techniques that are used in the operational Level 2 processing algorithms. The RTMs assessed are LIMBTRAN, VECTOR, SCIARAYS, and SASKTRAN. The solvers studied include the Maximum A Posteriori (MAP), Maximum Likelihood (ML), Iterative Least Squares (ILS), and Chahine methods.

  1. The Psychology of Choice.

    ERIC Educational Resources Information Center

    Lickona, Thomas

    A basic quality of the open classroom is that children are encouraged to make choices. Psychological rationales for allowing children to make choices are taken from psychological theory: (1) the objective of education, stated by Piaget and others, is to develop creative and independent thinkers; (2) children are intrinsically motivated to learn:…

  2. The Choice Controversy.

    ERIC Educational Resources Information Center

    Cookson, Peter W., Jr., Ed.

    Issues in school choice--constitutionality, feasibility, equity, and educational productivity--are examined in this book. The controversy requires an ongoing analysis of the origins of the school-choice movement, the kinds of plans proposed and implemented, their educational and social consequences, and the philosophical assumptions underlying the…

  3. Children's Choices for 2008

    ERIC Educational Resources Information Center

    Reading Teacher, 2008

    2008-01-01

    Each year 12,500 school children from different regions of the United States read and vote on the newly published children's and young adults' trade books that they like best. The Children's Choices for 2008 list is the 34th in a series that first appeared as "Classroom Choices" in the November 1975 issue of "The Reading Teacher" (RT), a…

  4. Children's Choices for 2002.

    ERIC Educational Resources Information Center

    Reading Teacher, 2002

    2002-01-01

    Presents annotations of children's choices of the top 100 children's and young adults' trade books for 2002. Lists books selected for the Children's Choice by reading levels: beginning readers; young readers; intermediate readers; and advanced readers. Provides tips and activities for parents, primary caregivers, and educators. (SG)

  5. Making School Choice Work

    ERIC Educational Resources Information Center

    DeArmond, Michael; Jochim, Ashley; Lake, Robin

    2014-01-01

    School choice is increasingly the new normal in urban education. But in cities with multiple public school options, how can civic leaders create a choice system that works for all families, whether they choose a charter or district public school? To answer this question, the Center on Reinventing Public Education (CRPE) researchers surveyed 4,000…

  6. Your Genes, Your Choices

    MedlinePlus

    Table of Contents Your Genes, Your Choices describes the Human Genome Project, the science behind it, and the ethical, legal, and social issues that are ... Nothing could be further from the truth. Your Genes, Your Choices points out how the progress of ...

  7. More Choice, Less Crime

    ERIC Educational Resources Information Center

    Dills, Angela K.; Hernandez-Julian, Rey

    2011-01-01

    Previous research debates whether public school choice improves students' academic outcomes, but there is little examination of its effects on their nonacademic outcomes. We use data from a nationally representative sample of high school students, a previously developed Tiebout choice measure, and metropolitan-level data on teenage arrest rates to…

  8. Latinos and School Choice

    ERIC Educational Resources Information Center

    Gastic, Billie; Coronado, Diana Salas

    2011-01-01

    The authors describe how Latino students are underrepresented in public schools of choice. They provide evidence to refute the claim that Latino students who choose to leave assigned public schools enroll in religious schools instead. Charter schools stand out as the type of public schools of choice where Latino students are well represented.…

  9. Career Choice Conflict.

    ERIC Educational Resources Information Center

    Behymer, Jo; Cockriel, Irvin W.

    1988-01-01

    The study attempted to determine the effect of availability of scholarships and loans on the career choice of high school juniors and seniors. A survey of 911 college-bound students revealed that 89 percent considered availability of scholarships important to career choice, and 84 percent considered loan availability important. (CH)

  10. School Choice Marches forward

    ERIC Educational Resources Information Center

    Butcher, Jonathan

    2013-01-01

    One year ago, the "Wall Street Journal" dubbed 2011 "the year of school choice," opining that "this year is shaping up as the best for reformers in a very long time." School-choice laws took great strides in 2011, both in the number of programs that succeeded across states and also in the size and scope of the adopted programs. Yet education…

  11. Choice: The Historical Perspective.

    ERIC Educational Resources Information Center

    Wagoner, Jennings L., Jr.

    The issue of choice in U.S. education is traced historically. Consideration is given to the purposes of publicly supported education and reasons underlying the historic distinction between public and private education. It is suggested that the issue of choice concerns the rights and obligations of the individual and the state. The relationship…

  12. Measuring saliency in images: which experimental parameters for the assessment of image quality?

    NASA Astrophysics Data System (ADS)

    Fredembach, Clement; Woolfe, Geoff; Wang, Jue

    2012-01-01

    Predicting which areas of an image are perceptually salient or attended to has become an essential pre-requisite of many computer vision applications. Because observers are notoriously unreliable in remembering where they look a posteriori, and because asking where they look while observing the image necessarily in uences the results, ground truth about saliency and visual attention has to be obtained by gaze tracking methods. From the early work of Buswell and Yarbus to the most recent forays in computer vision there has been, perhaps unfortunately, little agreement on standardisation of eye tracking protocols for measuring visual attention. As the number of parameters involved in experimental methodology can be large, their individual in uence on the nal results is not well understood. Consequently, the performance of saliency algorithms, when assessed by correlation techniques, varies greatly across the literature. In this paper, we concern ourselves with the problem of image quality. Specically: where people look when judging images. We show that in this case, the performance gap between existing saliency prediction algorithms and experimental results is signicantly larger than otherwise reported. To understand this discrepancy, we rst devise an experimental protocol that is adapted to the task of measuring image quality. In a second step, we compare our experimental parameters with the ones of existing methods and show that a lot of the variability can directly be ascribed to these dierences in experimental methodology and choice of variables. In particular, the choice of a task, e.g., judging image quality vs. free viewing, has a great impact on measured saliency maps, suggesting that even for a mildly cognitive task, ground truth obtained by free viewing does not adapt well. Careful analysis of the prior art also reveals that systematic bias can occur depending on instrumental calibration and the choice of test images. We conclude this work by proposing a

  13. Colorado's clean energy choices

    SciTech Connect

    Strawn, N.; Jones, J.

    2000-04-15

    The daily choices made as consumers affect the environment and the economy. Based on the state of today's technology and economics, Colorado consumers can include energy efficiency and renewable energy into many aspects of their lives. These choices include where they obtain electricity, how they use energy at home, and how they transport themselves from one place to another. In addition to outlining how they can use clean energy, Colorado's Clean Energy Choices gives consumers contacts and links to Web sites for where to get more information.

  14. Model choice for decision making under uncertainty

    NASA Astrophysics Data System (ADS)

    Bàrdossy, Andràs

    2015-04-01

    Present and future water management decisions are often supported by modelling. The choice of the appropriate model and model parameters depend on the decision related question, the quality of the model and the available information. While spatially detailed physics based models might seem very transferable, the uncertainty of the parametrization and of the input may lead to highly diverging results, which are of no use for decision making. The optimal model choice requires a quantification of the input/natural parameter uncertainty. As a next step the influence of this uncertainty on predictions using models with different complexity has to be quantified. Finally the influence of this prediction uncertainty on the decisions to be taken has to be assessed. Different data/information availability and modelling questions thus might require different modelling approaches. A framework for this model choice and parametrization problem will be presented together with examples from regions with very different data availability and data quality.

  15. Sequential sampling and paradoxes of risky choice.

    PubMed

    Bhatia, Sudeep

    2014-10-01

    The common-ratio, common-consequence, reflection, and event-splitting effects are some of the best-known findings in decision-making research. They represent robust violations of expected utility theory, and together form a benchmark against which descriptive theories of risky choice are tested. These effects are not currently predicted by sequential sampling models of risky choice, such as decision field theory (Busemeyer & Townsend 1993). This paper, however, shows that a minor extension to decision field theory, which allows for stochastic error in event sampling, can provide a parsimonious, cognitively plausible explanation for these effects. Moreover, these effects are guaranteed to emerge for a large range of parameter values, including best-fit parameters obtained from preexisting choice data. PMID:24898202

  16. Choice, changeover, and travel

    PubMed Central

    Baum, William M.

    1982-01-01

    Since foraging in nature can be viewed as instrumental behavior, choice between sources of food, known as “patches,” can be viewed as choice between instrumental response alternatives. Whereas the travel required to change alternatives deters changeover in nature, the changeover delay (COD) usually deters changeover in the laboratory. In this experiment, pigeons were exposed to laboratory choice situations, concurrent variable-interval schedules, that were standard except for the introduction of a travel requirement for changeover. As the travel requirement increased, rate of changeover decreased and preference for a favored alternative strengthened. When the travel requirement was small, the relations between choice and relative reinforcement revealed the usual tendencies toward matching and undermatching. When the travel requirement was large, strong overmatching occurred. These results, together with those from experiments in which changeover was deterred by punishment or a fixed-ratio requirement, deviate from the matching law, even when a correction is made for cost of changeover. If one accepted an argument that the COD is analogous to travel, the results suggest that the norm in choice relations would be overmatching. This overmatching, however, might only be the sign of an underlying strategy approximating optimization. PMID:16812283

  17. Measuring improved patient choice.

    PubMed

    Holmes-Rovner, M; Rovner, D R

    2000-08-01

    Patient decision support (PDS) tools or decision aids have been developed as adjuncts to the clinical encounter. Their aim is to support evidence-based patient choice. Clinical trials of PDS tools have used an array of outcome measures to determine efficacy, including knowledge, satisfaction, health status and consistency between patient choice and values. This paper proposes that the correlation between 'subjective expected utility' (SEU) and decision may be the best primary endpoint for trials. SEU is a measure usually used in behavioural decision theory. The paper first describes how decision support tools may use decision analysis to structure the presentation of evidence and guide patient decision-making. Uses of expected utility (EU) are suggested for evaluating PDS tools when improving population health status is the objective. SEU is the theoretically better measure when internal consistency of patient choices is the objective. PMID:11083037

  18. Choosing health, constrained choices.

    PubMed

    Chee Khoon Chan

    2009-12-01

    In parallel with the neo-liberal retrenchment of the welfarist state, an increasing emphasis on the responsibility of individuals in managing their own affairs and their well-being has been evident. In the health arena for instance, this was a major theme permeating the UK government's White Paper Choosing Health: Making Healthy Choices Easier (2004), which appealed to an ethos of autonomy and self-actualization through activity and consumption which merited esteem. As a counterpoint to this growing trend of informed responsibilization, constrained choices (constrained agency) provides a useful framework for a judicious balance and sense of proportion between an individual behavioural focus and a focus on societal, systemic, and structural determinants of health and well-being. Constrained choices is also a conceptual bridge between responsibilization and population health which could be further developed within an integrative biosocial perspective one might refer to as the social ecology of health and disease. PMID:20028669

  19. The problem of choice

    PubMed Central

    Naqvi, Hassan R; Mathur, Shawn; Covarrubias, David; Curcio, Josephine A; Schmidt, Christian

    2008-01-01

    Convictions are a driving force for actions. Considering that every individual has a different set of convictions and larger groups act once a consensus decision is reached, one can see that debate is an inherent exercise in decision-making. This requires a sustainably generated surplus to allow time for intellectual exchange, gathering of information and dissemination of findings. It is essential that the full spectrum of options remain treated equally. At the end of this process, a choice has to be made. Looking back at a later time point, a retrospective analysis sometimes reveals that the choice was neither completely free nor a truly conscious one. Leaving the issue of consequences of a once made decision aside, we wish to contribute to the debate of the problem of choice. PMID:19025607

  20. Special Issue Topic: School Choice.

    ERIC Educational Resources Information Center

    Brogan, Bernard R.; And Others

    1991-01-01

    Includes "The Choice Movement" (Brogan); "Choice in American Education" (Witte); "Role of Parents in Education" (Mawdsley); "As Arrows in the Hand" (Coons); "Vouchers in Wisconsin" (Underwood); "Milwaukee Parental Choice Program (MPCP)" (Grover); "Civil Liberties and the MPCP" (Bolick); "Comments on School Choice" (Jauch); "Two Classes of…

  1. Deterministic Walks with Choice

    SciTech Connect

    Beeler, Katy E.; Berenhaut, Kenneth S.; Cooper, Joshua N.; Hunter, Meagan N.; Barr, Peter S.

    2014-01-10

    This paper studies deterministic movement over toroidal grids, integrating local information, bounded memory and choice at individual nodes. The research is motivated by recent work on deterministic random walks, and applications in multi-agent systems. Several results regarding passing tokens through toroidal grids are discussed, as well as some open questions.

  2. Children's Choices for 2003.

    ERIC Educational Resources Information Center

    Reading Teacher, 2003

    2003-01-01

    Presents 103 titles for the 2003 Children's Choice grouped by reading levels: beginning, young, intermediate, and advanced readers. Provides the title, author, illustrator, publisher, ISBN, and price for each title as well as a brief annotation prepared by a review team. (SG)

  3. Children's Choice for 2001.

    ERIC Educational Resources Information Center

    Reading Teacher, 2001

    2001-01-01

    Presents a 25-item annotated bibliography for beginning readers, 30 items for young readers, 19 items for intermediate readers, and 24 items for advanced readers--all selected by children. Gives tips for parents, primary caregivers, and educators. Describes the Children's Choice project and book selection. (SG)

  4. Geography in Parental Choice

    ERIC Educational Resources Information Center

    Bell, Courtney

    2009-01-01

    If we are to fully understand the demand side of school choice, we have to understand geography. But geography is not simply distance and commute time. It is also neighborhood and community. Using two conceptions of geography--space and place--I investigate how and when geography factored into parents' thinking. Drawing on spatial analyses of…

  5. Supporting Family Choice

    ERIC Educational Resources Information Center

    Murray, Mary M.; Christensen, Kimberly A.; Umbarger, Gardner T.; Rade, Karin C.; Aldridge, Kathryn; Niemeyer, Judith A.

    2007-01-01

    Supporting family choice in the decision-making process is recommended practice in the field of early childhood and early childhood special education. These decisions may relate to the medical, educational, social, recreational, therapeutic/rehabilitative, and community aspects of the child's disability. Although this practice conveys the message…

  6. Variation, Repetition, and Choice

    ERIC Educational Resources Information Center

    Abreu-Rodrigues, Josele; Lattal, Kennon A.; dos Santos, Cristiano V.; Matos, Ricardo A.

    2005-01-01

    Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a…

  7. The Choice for Learning

    ERIC Educational Resources Information Center

    Bennett, Scott

    2006-01-01

    We are building conventional library space without making the paradigm shift our digital environment requires. The chief obstacles to change lie in our conception of readers as information consumers, in our allegiance to library operations as the drivers of library design, and in the choice made between foundational and non-foundational views of…

  8. Choices, Frameworks and Refinement

    NASA Technical Reports Server (NTRS)

    Campbell, Roy H.; Islam, Nayeem; Johnson, Ralph; Kougiouris, Panos; Madany, Peter

    1991-01-01

    In this paper we present a method for designing operating systems using object-oriented frameworks. A framework can be refined into subframeworks. Constraints specify the interactions between the subframeworks. We describe how we used object-oriented frameworks to design Choices, an object-oriented operating system.

  9. Learning from School Choice.

    ERIC Educational Resources Information Center

    Peterson, Paul E., Ed.; Hassel, Bryan C., Ed.

    This volume contains revised versions of 16 essays presented at a conference, "Rethinking School Governance," hosted by Harvard's Program on Education Policy and Governance in June 1997. Part 1, "Introduction," contains two chapters: (1) "School Choice: A Report Card" (Paul E. Peterson); and (2) "The Case for Charter Schools" (Bryan C. Hassel).…

  10. Fixing the c Parameter in the Three-Parameter Logistic Model

    ERIC Educational Resources Information Center

    Han, Kyung T.

    2012-01-01

    For several decades, the "three-parameter logistic model" (3PLM) has been the dominant choice for practitioners in the field of educational measurement for modeling examinees' response data from multiple-choice (MC) items. Past studies, however, have pointed out that the c-parameter of 3PLM should not be interpreted as a guessing parameter. This…

  11. Influencing choice without awareness.

    PubMed

    Olson, Jay A; Amlani, Alym A; Raz, Amir; Rensink, Ronald A

    2015-12-01

    Forcing occurs when a magician influences the audience's decisions without their awareness. To investigate the mechanisms behind this effect, we examined several stimulus and personality predictors. In Study 1, a magician flipped through a deck of playing cards while participants were asked to choose one. Although the magician could influence the choice almost every time (98%), relatively few (9%) noticed this influence. In Study 2, participants observed rapid series of cards on a computer, with one target card shown longer than the rest. We expected people would tend to choose this card without noticing that it was shown longest. Both stimulus and personality factors predicted the choice of card, depending on whether the influence was noticed. These results show that combining real-world and laboratory research can be a powerful way to study magic and can provide new methods to study the feeling of free will. PMID:25666736

  12. Recursive rational choice

    SciTech Connect

    Lewis, A.A.

    1981-11-01

    It is the purpose of the present study to indicate the means by which Kramer's results may be generalized to considerations of stronger computing devices than the finite state automata considered in Kramer's approach, and to domains of alternatives having the cardinality of the continuum. The means we employ in the approach makes use of the theory of recursive functions in the context of Church's Thesis. The result, which we consider as a preliminary result to a more general research program, shows that a choice function that is rational in the sense of Richter (not necessarily regular) when defined on a restricted family of subsets of a continuum of alternatives, when recursively represented by a partial predicate on equivalence classes of approximations by rational numbers, is recursively unsolvable. By way of Church's Thesis, therefore, such a function cannot be realized by means of a very general class of effectively computable procedures. An additional consequence that can be derived from the result of recursive unsolvability of rational choice in this setting is the placement of a minimal bound on the amount of computational complexity entailed by effective realizations of rational choice.

  13. Alternative fuels and vehicles choice model

    SciTech Connect

    Greene, D.L.

    1994-10-01

    This report describes the theory and implementation of a model of alternative fuel and vehicle choice (AFVC), designed for use with the US Department of Energy`s Alternative Fuels Trade Model (AFTM). The AFTM is a static equilibrium model of the world supply and demand for liquid fuels, encompassing resource production, conversion processes, transportation, and consumption. The AFTM also includes fuel-switching behavior by incorporating multinomial logit-type equations for choice of alternative fuel vehicles and alternative fuels. This allows the model to solve for market shares of vehicles and fuels, as well as for fuel prices and quantities. The AFVC model includes fuel-flexible, bi-fuel, and dedicated fuel vehicles. For multi-fuel vehicles, the choice of fuel is subsumed within the vehicle choice framework, resulting in a nested multinomial logit design. The nesting is shown to be required by the different price elasticities of fuel and vehicle choice. A unique feature of the AFVC is that its parameters are derived directly from the characteristics of alternative fuels and vehicle technologies, together with a few key assumptions about consumer behavior. This not only establishes a direct link between assumptions and model predictions, but facilitates sensitivity testing, as well. The implementation of the AFVC model as a spreadsheet is also described.

  14. Optimal filtration of the atmospheric parameters profiles

    NASA Technical Reports Server (NTRS)

    Zuev, V. E.; Glazov, G. N.; Igonin, G. M.

    1986-01-01

    The idea of optimal Marcovian filtration of fluctuating profiles from lidar signals is developed but as applied to a double-frequency sounding which allows the use of large cross sections of elastic scattering and correct separation of the contributions due to aerosol and Rayleigh scatterings from the total lidar return. The filtration efficiency is shown under different conditions of sounding using a computer model. The accuracy of restituted profiles (temperature, pressure, density) is determined by the elements of a posteriori matrix K. The results obtained allow the determination of the lidar power required for providing the necessary accuracy of restitution of the atmospheric parameter profiles at chosen wavelengths of sounding in the ultraviolet and visible range.

  15. The Malleability of Intertemporal Choice.

    PubMed

    Lempert, Karolina M; Phelps, Elizabeth A

    2016-01-01

    Intertemporal choices are ubiquitous: people often have to choose between outcomes realized at different times. Although it is generally believed that people have stable tendencies toward being impulsive or patient, an emerging body of evidence indicates that intertemporal choice is malleable and can be profoundly influenced by context. How the choice is framed, or the state of the decision-maker at the time of choice, can induce a shift in preference. Framing effects are underpinned by allocation of attention to choice attributes, reference dependence, and time construal. Incidental affective states and prospection also influence intertemporal choice. We advocate that intertemporal choice models account for these context effects, and encourage the use of this knowledge to nudge people toward making more advantageous choices. PMID:26483153

  16. Dynamics of Choice: A Tutorial

    ERIC Educational Resources Information Center

    Baum, William M.

    2010-01-01

    Choice may be defined as the allocation of behavior among activities. Since all activities take up time, choice is conveniently thought of as the allocation of time among activities, even if activities like pecking are most easily measured by counting. Since dynamics refers to change through time, the dynamics of choice refers to change of…

  17. Understanding Career Choices in Context.

    ERIC Educational Resources Information Center

    Minor, Carole W.; Vermeulen, Mary E.; Coy, Doris Rhea

    Over several years, challenges have been made to traditional theories of career choice. One of these challenges has been to consider the contexts in which individuals live and how this can influence career choices. The purpose of this model is to create a framework to explain the influences on career choices over the lifespan. The term "career…

  18. Overconfidence and Career Choice.

    PubMed

    Schulz, Jonathan F; Thöni, Christian

    2016-01-01

    People self-assess their relative ability when making career choices. Thus, confidence in their own abilities is likely an important factor for selection into various career paths. In a sample of 711 first-year students we examine whether there are systematic differences in confidence levels across fields of study. We find that our experimental confidence measures significantly vary between fields of study: While students in business related academic disciplines (Political Science, Law, Economics, and Business Administration) exhibit the highest confidence levels, students of Humanities range at the other end of the scale. This may have important implications for subsequent earnings and professions students select themselves in. PMID:26808273

  19. Overconfidence and Career Choice

    PubMed Central

    Schulz, Jonathan F.; Thöni, Christian

    2016-01-01

    People self-assess their relative ability when making career choices. Thus, confidence in their own abilities is likely an important factor for selection into various career paths. In a sample of 711 first-year students we examine whether there are systematic differences in confidence levels across fields of study. We find that our experimental confidence measures significantly vary between fields of study: While students in business related academic disciplines (Political Science, Law, Economics, and Business Administration) exhibit the highest confidence levels, students of Humanities range at the other end of the scale. This may have important implications for subsequent earnings and professions students select themselves in. PMID:26808273

  20. A Bayesian approach to tracking patients having changing pharmacokinetic parameters

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Jelliffe, Roger W.

    2004-01-01

    This paper considers the updating of Bayesian posterior densities for pharmacokinetic models associated with patients having changing parameter values. For estimation purposes it is proposed to use the Interacting Multiple Model (IMM) estimation algorithm, which is currently a popular algorithm in the aerospace community for tracking maneuvering targets. The IMM algorithm is described, and compared to the multiple model (MM) and Maximum A-Posteriori (MAP) Bayesian estimation methods, which are presently used for posterior updating when pharmacokinetic parameters do not change. Both the MM and MAP Bayesian estimation methods are used in their sequential forms, to facilitate tracking of changing parameters. Results indicate that the IMM algorithm is well suited for tracking time-varying pharmacokinetic parameters in acutely ill and unstable patients, incurring only about half of the integrated error compared to the sequential MM and MAP methods on the same example.

  1. Variation, Repetition, And Choice

    PubMed Central

    Abreu-Rodrigues, Josele; Lattal, Kennon A; dos Santos, Cristiano V; Matos, Ricardo A

    2005-01-01

    Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a response sequence in the terminal link was reinforced only if it differed from the n previous sequences (lag criterion). The REPEAT contingency generated low, constant levels of sequence variation whereas the VARY contingency produced levels of sequence variation that increased with the lag criterion. Preference for the REPEAT alternative tended to increase directly with the degree of variation required for reinforcement. Experiment 2 examined the potential confounding effects in Experiment 1 of immediacy of reinforcement by yoking the interreinforcer intervals in the REPEAT alternative to those in the VARY alternative. Again, preference for REPEAT was a function of the lag criterion. Choice between varying and repeating behavior is discussed with respect to obtained behavioral variability, probability of reinforcement, delay of reinforcement, and switching within a sequence. PMID:15828592

  2. Motherhood as a choice.

    PubMed

    Mcfadden, P

    1994-06-01

    The choice of motherhood for women and women's rights have been forbidden in law by men, in religious doctrines by men, and within the medical system by men. Women in poverty have little say in determining whether to have children or not. When choice is exercised for abortion, poor women have unsafe and illegal abortions, which can be life-threatening. Rich women have safer options. Women historically have allowed their rights to be eroded by gender inequality and patriarchal manipulation. The religious right and the Roman Catholic church have been allowed to speak and decide for women. Abortion rights are not about western influences, but about maternal mortality. The right to make choices about one's life is the fundamental premise of the universal rights of all human beings. African governments have signed the UN Convention on elimination of all forms of discrimination against women, but the practice of human rights has not been implemented at the local and family level. Motherhood needs to be demystified. Motherhood is linked with the absence of personhood and bodily integrity. The rhetoric of moral obligations and the rights of the unborn child take precedence over the rights of women. The right of an African woman not to have children is not recognized in most Africa societies. The issue of AIDS creates an even more difficult milieu for women. The interests of the family and the interests of men overwhelm the interests of women to protect themselves. Motherhood is essential to validating one's heterosexuality and gaining stature, and females without a child are marginalized and unrecognized. Women whose babies do not survive are marginalized further than barren women. Men derive power from women's birthing. The terminology of male power is replete with expressions such as "pregnant with promise" and "miscarriage of justice's", no one says "uterus envy." Male psychologists only recognize "penis envy." Men need children for purposes of property, lineage, and

  3. A simple robust and accurate a posteriori sub-cell finite volume limiter for the discontinuous Galerkin method on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Dumbser, Michael; Loubère, Raphaël

    2016-08-01

    In this paper we propose a simple, robust and accurate nonlinear a posteriori stabilization of the Discontinuous Galerkin (DG) finite element method for the solution of nonlinear hyperbolic PDE systems on unstructured triangular and tetrahedral meshes in two and three space dimensions. This novel a posteriori limiter, which has been recently proposed for the simple Cartesian grid case in [62], is able to resolve discontinuities at a sub-grid scale and is substantially extended here to general unstructured simplex meshes in 2D and 3D. It can be summarized as follows: At the beginning of each time step, an approximation of the local minimum and maximum of the discrete solution is computed for each cell, taking into account also the vertex neighbors of an element. Then, an unlimited discontinuous Galerkin scheme of approximation degree N is run for one time step to produce a so-called candidate solution. Subsequently, an a posteriori detection step checks the unlimited candidate solution at time t n + 1 for positivity, absence of floating point errors and whether the discrete solution has remained within or at least very close to the bounds given by the local minimum and maximum computed in the first step. Elements that do not satisfy all the previously mentioned detection criteria are flagged as troubled cells. For these troubled cells, the candidate solution is discarded as inappropriate and consequently needs to be recomputed. Within these troubled cells the old discrete solution at the previous time tn is scattered onto small sub-cells (Ns = 2 N + 1 sub-cells per element edge), in order to obtain a set of sub-cell averages at time tn. Then, a more robust second order TVD finite volume scheme is applied to update the sub-cell averages within the troubled DG cells from time tn to time t n + 1. The new sub-grid data at time t n + 1 are finally gathered back into a valid cell-centered DG polynomial of degree N by using a classical conservative and higher order

  4. Parental Voucher Enrollment Decisions: Choice within Choice in New Orleans

    ERIC Educational Resources Information Center

    Beabout, Brian R.; Cambre, Belinda M.

    2013-01-01

    Set in the context of a choice-saturated public school system, this study examines the school choice process of low-income parents who participated in Louisiana's 2008 voucher program. Based on semistructured interviews with 16 parents at 1 Catholic school, we report that spirituality, small class and school size, character/values,…

  5. Addiction: Choice or Compulsion?

    PubMed Central

    Henden, Edmund; Melberg, Hans Olav; Røgeberg, Ole Jørgen

    2013-01-01

    Normative thinking about addiction has traditionally been divided between, on the one hand, a medical model which sees addiction as a disease characterized by compulsive and relapsing drug use over which the addict has little or no control and, on the other, a moral model which sees addiction as a choice characterized by voluntary behavior under the control of the addict. Proponents of the former appeal to evidence showing that regular consumption of drugs causes persistent changes in the brain structures and functions known to be involved in the motivation of behavior. On this evidence, it is often concluded that becoming addicted involves a transition from voluntary, chosen drug use to non-voluntary compulsive drug use. Against this view, proponents of the moral model provide ample evidence that addictive drug use involves voluntary chosen behavior. In this article we argue that although they are right about something, both views are mistaken. We present a third model that neither rules out the view of addictive drug use as compulsive, nor that it involves voluntary chosen behavior. PMID:23966955

  6. Hybrid discrete choice models: Gained insights versus increasing effort.

    PubMed

    Mariel, Petr; Meyerhoff, Jürgen

    2016-10-15

    Hybrid choice models expand the standard models in discrete choice modelling by incorporating psychological factors as latent variables. They could therefore provide further insights into choice processes and underlying taste heterogeneity but the costs of estimating these models often significantly increase. This paper aims at comparing the results from a hybrid choice model and a classical random parameter logit. Point of departure for this analysis is whether researchers and practitioners should add hybrid choice models to their suite of models routinely estimated. Our comparison reveals, in line with the few prior studies, that hybrid models gain in efficiency by the inclusion of additional information. The use of one of the two proposed approaches, however, depends on the objective of the analysis. If disentangling preference heterogeneity is most important, hybrid model seems to be preferable. If the focus is on predictive power, a standard random parameter logit model might be the better choice. Finally, we give recommendations for an adequate use of hybrid choice models based on known principles of elementary scientific inference. PMID:27310534

  7. School Choice: Examining the Evidence.

    ERIC Educational Resources Information Center

    Rasell, Edith, Ed.; Rothstein, Richard, Ed.

    This book presents a summary of school-choice issues, and is organized around a 1992 seminar entitled "Choice: What Role in American Education?" Each part presents a set of conference papers, followed by discussants' remarks and excerpts from audience discussion. The introduction summarizes the papers' positions and conclusions. Participants…

  8. PATERNAL INFLUENCE ON CAREER CHOICE.

    ERIC Educational Resources Information Center

    WERTS, CHARLES E.

    FATHER'S OCCUPATION WAS COMPARED WITH SON'S CAREER CHOICE FOR A SAMPLE OF 76,015 MALE, COLLEGE FRESHMEN. RESULTS INDICATED THAT CERTAIN TYPES OF FATHERS' OCCUPATIONS WERE ASSOCIATED WITH SIMILAR TYPES OF CAREER CHOICES BY SONS. BOYS WHOSE FATHERS WERE IN SCIENTIFIC OCCUPATIONS (ENGINEERS, MILITARY OFFICERS, ARCHITECTS, BIOLOGISTS, CHEMISTS, AND…

  9. Preference Reversal in Multiattribute Choice

    ERIC Educational Resources Information Center

    Tsetsos, Konstantinos; Usher, Marius; Chater, Nick

    2010-01-01

    A central puzzle for theories of choice is that people's preferences between options can be reversed by the presence of decoy options (that are not chosen) or by the presence of other irrelevant options added to the choice set. Three types of reversal effect reported in the decision-making literature, the attraction, compromise, and similarity…

  10. The Supply Side of Choice

    ERIC Educational Resources Information Center

    Hill, Paul T.

    2005-01-01

    New school creation is key to success of choice. For the last two decades, the struggle over school choice has focused on freeing up parents to choose. It continues to this day, with growing success in the forms of public and private voucher programs, charter school laws in 40 states and the District of Columbia, and state and federal laws that…

  11. Contextual Explanations of School Choice

    ERIC Educational Resources Information Center

    Lauen, Douglas Lee

    2007-01-01

    Participation in school-choice programs has been increasing across the country since the early 1990s. While some have examined the role that families play in the school-choice process, research has largely ignored the role of social contexts in determining where a student attends school. This article improves on previous research by modeling the…

  12. School Choice with Chinese Characteristics

    ERIC Educational Resources Information Center

    Wu, Xiaoxin

    2012-01-01

    This paper explores the major characteristics of school choice in the Chinese context. It highlights the involvement of cultural and economic capital, such as choice fees, donations, prize-winning certificates and awards in gaining school admission, as well as the use of social capital in the form of "guanxi". The requirement for these resources…

  13. Putting School Choice in Place.

    ERIC Educational Resources Information Center

    Glenn, Charles L.

    1989-01-01

    School choice should be promoted only under conditions guaranteeing that costs will be outweighed by benefits. Implementing choice means developing an effective assignment policy, conducting parent surveys, providing for adequate staff involvement, committing to parent outreach, managing effects on individual schools, and setting up a…

  14. School Choice: To What End?

    ERIC Educational Resources Information Center

    Wagner, Tony

    1996-01-01

    Debunks two fantasies: the feasibility of a free-market educational system and the idea that greater choice automatically means better schools. Public education is too labor-intensive and undercapitalized to be profitable. Communities need "skunk works" schools of choice to do research and development and smaller, collaboratively managed schools…

  15. Eye Movements in Risky Choice

    PubMed Central

    Hermens, Frouke; Matthews, William J.

    2015-01-01

    Abstract We asked participants to make simple risky choices while we recorded their eye movements. We built a complete statistical model of the eye movements and found very little systematic variation in eye movements over the time course of a choice or across the different choices. The only exceptions were finding more (of the same) eye movements when choice options were similar, and an emerging gaze bias in which people looked more at the gamble they ultimately chose. These findings are inconsistent with prospect theory, the priority heuristic, or decision field theory. However, the eye movements made during a choice have a large relationship with the final choice, and this is mostly independent from the contribution of the actual attribute values in the choice options. That is, eye movements tell us not just about the processing of attribute values but also are independently associated with choice. The pattern is simple—people choose the gamble they look at more often, independently of the actual numbers they see—and this pattern is simpler than predicted by decision field theory, decision by sampling, and the parallel constraint satisfaction model. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd. PMID:27522985

  16. The Globalisation of School Choice?

    ERIC Educational Resources Information Center

    Forsey, Martin, Ed.; Davies, Scott, Ed.; Walford, Geoffrey, Ed.

    2008-01-01

    "Which school should I choose for my child?" For many parents, this question is one of the most important of their lives. "School choice" is a slogan being voiced around the globe, conjuring images of a marketplace with an abundance of educational options. Those promoting educational choice also promise equality, social advantage, autonomy, and…

  17. Religious Education and Religious Choice

    ERIC Educational Resources Information Center

    Hand, Michael

    2015-01-01

    According to the "religious choice case" for compulsory religious education, pupils have a right to be made aware of the religious and irreligious paths open to them and equipped with the wherewithal to choose between them. A familiar objection to this argument is that the idea of religious choice reduces religion to a matter of taste. I…

  18. School Choice: A Report Card.

    ERIC Educational Resources Information Center

    Peterson, Paul E.

    1998-01-01

    Locates school choice's theoretical underpinnings in market theory and communitarianism. Explains contributions of magnet schools, charter schools, and voucher systems to the choice movement. Summarizes preliminary findings for voucher plans, highlighting minority participation, family and teacher satisfaction, student mobility, and college…

  19. College Choice in the Philippines

    ERIC Educational Resources Information Center

    Tan, Christine Joy

    2009-01-01

    This descriptive and correlational study examined the applicability of major U.S. college choice factors to Philippine high school seniors. A sample of 226 students from a private school in Manila completed the College Choice Survey for High School Seniors. Cronbach's alpha for the survey composite index was 0.933. The purposes of this…

  20. The logistics of choice.

    PubMed

    Killeen, Peter R

    2015-07-01

    The generalized matching law (GML) is reconstructed as a logistic regression equation that privileges no particular value of the sensitivity parameter, a. That value will often approach 1 due to the feedback that drives switching that is intrinsic to most concurrent schedules. A model of that feedback reproduced some features of concurrent data. The GML is a law only in the strained sense that any equation that maps data is a law. The machine under the hood of matching is in all likelihood the very law that was displaced by the Matching Law. It is now time to return the Law of Effect to centrality in our science. PMID:25988932

  1. Eye Movements in Strategic Choice

    PubMed Central

    Gächter, Simon; Noguchi, Takao; Mullett, Timothy L.

    2015-01-01

    Abstract In risky and other multiattribute choices, the process of choosing is well described by random walk or drift diffusion models in which evidence is accumulated over time to threshold. In strategic choices, level‐k and cognitive hierarchy models have been offered as accounts of the choice process, in which people simulate the choice processes of their opponents or partners. We recorded the eye movements in 2 × 2 symmetric games including dominance‐solvable games like prisoner's dilemma and asymmetric coordination games like stag hunt and hawk–dove. The evidence was most consistent with the accumulation of payoff differences over time: we found longer duration choices with more fixations when payoffs differences were more finely balanced, an emerging bias to gaze more at the payoffs for the action ultimately chosen, and that a simple count of transitions between payoffs—whether or not the comparison is strategically informative—was strongly associated with the final choice. The accumulator models do account for these strategic choice process measures, but the level‐k and cognitive hierarchy models do not. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd.

  2. Motivational Basis of Choice in Three-Choice Decomposed Games

    ERIC Educational Resources Information Center

    McClintock, Charles G.; And Others

    1973-01-01

    One of the purposes of the present study was to determine the effectiveness of a three-choice situation that displays payoffs in a simple, direct and flexible manner for discriminating social motives. (Author/RK)

  3. Economic analysis of the first 20 years of universal hepatitis B vaccination program in Italy: an a posteriori evaluation and forecast of future benefits.

    PubMed

    Boccalini, Sara; Taddei, Cristina; Ceccherini, Vega; Bechini, Angela; Levi, Miriam; Bartolozzi, Dario; Bonanni, Paolo

    2013-05-01

    Italy was one of the first countries in the world to introduce a routine vaccination program against HBV for newborns and 12-y-old children. From a clinical point of view, such strategy was clearly successful. The objective of our study was to verify whether, at 20 y from its implementation, hepatitis B universal vaccination had positive effects also from an economic point of view. An a posteriori analysis evaluated the impact that the hepatitis B immunization program had up to the present day. The implementation of vaccination brought an extensive reduction of the burden of hepatitis B-related diseases in the Italian population. As a consequence, the past and future savings due to clinical costs avoided are particularly high. We obtained a return on investment nearly equal to 1 from the National Health Service perspective, and a benefit-to-cost ratio slightly less than 1 for the Societal perspective, considering only the first 20 y from the start of the program. In the longer-time horizon, ROI and BCR values were positive (2.78 and 2.46, respectively). The break-even point was already achieved few years ago for the NHS and for the Society, and since then more and more money is progressively saved. The implementation of universal hepatitis B vaccination was very favorable during the first 20 y of adoption, and further benefits will be increasingly evident in the future. The hepatitis B vaccination program in Italy is a clear example of the great impact that universal immunization is able to provide in the medium-long-term when health care authorities are so wise as to invest in prevention. PMID:23376840

  4. SU-E-J-170: Beyond Single-Cycle 4DCT: Maximum a Posteriori (MAP) Reconstruction-Based Binning-Free Multicycle 4DCT for Lung Radiotherapy

    SciTech Connect

    Cheung, Y; Sawant, A; Hinkle, J; Joshi, S

    2014-06-01

    Purpose: Thoracic motion changes from cycle-to-cycle and day-to-day. Conventional 4DCT does not capture these cycle to cycle variations. We present initial results of a novel 4DCT reconstruction technique based on maximum a posteriori (MAP) reconstruction. The technique uses the same acquisition process (and therefore dose) as a conventional 4DCT in order to create a high spatiotemporal resolution cine CT that captures several breathing cycles. Methods: Raw 4DCT data were acquired from a lung cancer patient. The continuous 4DCT was reconstructed using MAP algorithm which uses the raw, time-stamped CT data to reconstruct images while simultaneously estimating deformation in the subject's anatomy. This framework incorporates physical effects such as hysteresis and is robust to detector noise and irregular breathing patterns. The 4D image is described in terms of a 3D reference image defined at one end of the hysteresis loop, and two deformation vector fields (DVFs) corresponding to inhale motion and exhale motion respectively. The MAP method uses all of the CT projection data and maximizes the log posterior in order to iteratively estimate a timevariant deformation vector field that describes the entire moving and deforming volume. Results: The MAP 4DCT yielded CT-quality images for multiple cycles corresponding to the entire duration of CT acquisition, unlike the conventional 4DCT, which only yielded a single cycle. Variations such as amplitude and frequency changes and baseline shifts were clearly captured by the MAP 4DC Conclusion: We have developed a novel, binning-free, parameterized 4DCT reconstruction technique that can capture cycle-to-cycle variations of respiratory motion. This technique provides an invaluable tool for respiratory motion management research. This work was supported by funding from the National Institutes of Health and VisionRT Ltd. Amit Sawant receives research funding from Varian Medical Systems, Vision RT and Elekta.

  5. Understanding Parameter Invariance in Unidimensional IRT Models

    ERIC Educational Resources Information Center

    Rupp, Andre A.; Zumbo, Bruno D.

    2006-01-01

    One theoretical feature that makes item response theory (IRT) models those of choice for many psychometric data analysts is parameter invariance, the equality of item and examinee parameters from different examinee populations or measurement conditions. In this article, using the well-known fact that item and examinee parameters are identical only…

  6. Connecting cognition and consumer choice.

    PubMed

    Bartels, Daniel M; Johnson, Eric J

    2015-02-01

    We describe what can be gained from connecting cognition and consumer choice by discussing two contexts ripe for interaction between the two fields. The first-context effects on choice-has already been addressed by cognitive science yielding insights about cognitive process but there is promise for more interaction. The second is learning and representation in choice where relevant theories in cognitive science could be informed by consumer choice, and in return, could pose and answer new questions. We conclude by discussing how these two fields of research stand to benefit from more interaction, citing examples of how interfaces of cognitive science with other fields have been illuminating for theories of cognition. PMID:25527275

  7. How do stereotypes influence choice?

    PubMed

    Chaxel, Anne-Sophie

    2015-05-01

    In the study reported here, I tracked one process through which stereotypes affect choice. The Implicit Association Test (IAT) and a measurement of predecisional information distortion were used to assess the influence of the association between male gender and career on the evaluation of information related to the job performance of stereotypical targets (male) and nonstereotypical targets (female). When the IAT revealed a strong association between male gender and career and the installed leader in the choice process was a stereotypical target, decision makers supported the leader with more proleader distortion; when the IAT revealed a strong association between male gender and career and the installed leader in the choice process was a nonstereotypical target, decision makers supported the trailer with less antitrailer distortion. A stronger association between male gender and career therefore resulted in an upward shift of the evaluation related to the stereotypical target (both as a trailer and a leader), which subsequently biased choice. PMID:25749702

  8. Evoked emotions predict food choice.

    PubMed

    Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

    2014-01-01

    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores. PMID:25521352

  9. Modeling one-choice and two-choice driving tasks

    PubMed Central

    Ratcliff, Roger

    2015-01-01

    An experiment is presented in which subjects were tested on both one-choice and two-choice driving tasks and on non-driving versions of them. Diffusion models for one- and two-choice tasks were successful in extracting model-based measures from the response time and accuracy data. These include measures of the quality of the information from the stimuli that drove the decision process (drift rate in the model), the time taken up by processes outside the decision process and, for the two-choice model, the speed/accuracy decision criteria that subjects set. Drift rates were only marginally different between the driving and non-driving tasks, indicating that nearly the same information was used in the two kinds of tasks. The tasks differed in the time taken up by other processes, reflecting the difference between them in response processing demands. Drift rates were significantly correlated across the two two-choice tasks showing that subjects that performed well on one task also performed well on the other task. Nondecision times were correlated across the two driving tasks, showing common abilities on motor processes across the two tasks. These results show the feasibility of using diffusion modeling to examine decision making in driving and so provide for a theoretical examination of factors that might impair driving, such as extreme aging, distraction, sleep deprivation, and so on. PMID:25944448

  10. Developing a concept of choice.

    PubMed

    Kushnir, Tamar

    2012-01-01

    Our adult concept of choice is not a simple idea, but rather a complex set of beliefs about the causes of actions. These beliefs are situation-, individual- and culture-dependent, and are thus likely constructed through social learning. This chapter takes a rational constructivist approach to examining the development of a concept of choice in young children. Initially, infants' combine assumptions of rational agency with their capacity for statistical inference to reason about alternative possibilities for, and constraints on, action. Preschoolers' build on this basic understanding by integrating domain-specific causal knowledge of physical, biological, and psychological possibility into their appraisal of their own and others' ability to choose. However, preschoolers continue to view both psychological and social motivations as constraints on choice--for example, stating that one cannot choose to harm another, or to act against personal desires. It is not until later that children share the adult belief that choice mediates between conflicting motivations for action. The chapter concludes by suggesting avenues for future research--to better characterize conceptual changes in beliefs about choice, and to understand how such beliefs arise from children's everyday experiences. PMID:23205412

  11. Semiparametric Thurstonian Models for Recurrent Choices: A Bayesian Analysis

    ERIC Educational Resources Information Center

    Ansari, Asim; Iyengar, Raghuram

    2006-01-01

    We develop semiparametric Bayesian Thurstonian models for analyzing repeated choice decisions involving multinomial, multivariate binary or multivariate ordinal data. Our modeling framework has multiple components that together yield considerable flexibility in modeling preference utilities, cross-sectional heterogeneity and parameter-driven…

  12. Voice and choice by delegation.

    PubMed

    van de Bovenkamp, Hester; Vollaard, Hans; Trappenburg, Margo; Grit, Kor

    2013-02-01

    In many Western countries, options for citizens to influence public services are increased to improve the quality of services and democratize decision making. Possibilities to influence are often cast into Albert Hirschman's taxonomy of exit (choice), voice, and loyalty. In this article we identify delegation as an important addition to this framework. Delegation gives individuals the chance to practice exit/choice or voice without all the hard work that is usually involved in these options. Empirical research shows that not many people use their individual options of exit and voice, which could lead to inequality between users and nonusers. We identify delegation as a possible solution to this problem, using Dutch health care as a case study to explore this option. Notwithstanding various advantages, we show that voice and choice by delegation also entail problems of inequality and representativeness. PMID:23052688

  13. Does health affect portfolio choice?

    PubMed

    Love, David A; Smith, Paul A

    2010-12-01

    A number of recent studies find that poor health is empirically associated with a safer portfolio allocation. It is difficult to say, however, whether this relationship is truly causal. Both health status and portfolio choice are influenced by unobserved characteristics such as risk attitudes, impatience, information, and motivation, and these unobserved factors, if not adequately controlled for, can induce significant bias in the estimates of asset demand equations. Using the 1992-2006 waves of the Health and Retirement Study, we investigate how much of the connection between health and portfolio choice is causal and how much is due to the effects of unobserved heterogeneity. Accounting for unobserved heterogeneity with fixed effects and correlated random effects models, we find that health does not appear to significantly affect portfolio choice among single households. For married households, we find a small effect (about 2-3 percentage points) from being in the lowest of five self-reported health categories. PMID:19937612

  14. Evaluation of uncertainties in 90Sr-body-burdens obtained by whole-body count: application of Bayes' rule to derive detection limits by analysis of a posteriori data

    SciTech Connect

    Kozheurov, V. P.; Zalyapin, V. I.; Shagina, N. B.; Tokareva, E. E.; Degteva, M. O.; Tolstykh, E. I.; Anspaugh, L. R.; Napier, Bruce A.

    2002-10-01

    A whole body counter (WBC) designed to measure bremsstrahlung from 90Y, the short-lived daughter of 90Sr, has been used since 1974 to measure 90Sr-body burdens in residents along the Techa River, which was contaminated by releases from the Mayak Production Association. Bayes' rule has been applied to the a posteriori WBC data in order to derive the uncertainties associated with the data: The lower limit of reliable detection is 2.0kBq and the uncertainty of routine measurements is 1.6kBq.

  15. Evaluation of uncertainties in 90Sr-body-burdens obtained by whole-body count: application of Bayes' rule to derive detection limits by analysis of a posteriori data.

    PubMed

    Kozheurov, V P; Zalyapin, V I; Shagina, N B; Tokarevaa, E E; Degteva, M O; Tolstykh, E I; Anspaugh, L R; Napier, B A

    2002-10-01

    A whole body counter (WBC) designed to measure bremsstrahlung from 90Y, the short-lived daughter of 90Sr, has been used since 1974 to measure 90Sr-body burdens in residents along the Techa River, which was contaminated by releases from the Mayak Production Association. Bayes' rule has been applied to the a posteriori WBC data in order to derive the uncertainties associated with the data: The lower limit of reliable detection is 2.0 kBq and the uncertainty of routine measurements is 1.6 kBq. PMID:12361332

  16. From School Choice to Educational Choice. Education Outlook. No. 3

    ERIC Educational Resources Information Center

    Hess, Frederick M.; Meeks, Olivia; Manno, Bruno V.

    2011-01-01

    In recent decades, many calls for transformative change in American schooling have advocated school choice. Yet these calls themselves have too often accepted the orthodoxies of the nineteenth-century schoolhouse. In the new book "Customized Schooling: Beyond Whole-School Reform" (Harvard Education Press, 2011), the authors worked with the Walton…

  17. Florida CHOICES Counselor's Manual 1983-84.

    ERIC Educational Resources Information Center

    Glenn, Thomas R.; Rogers, Zelda

    This manual for counselors is intended for use with CHOICES, a computer assisted career guidance system. Following a brief introduction to CHOICES, the structure (in chart form) and an overview of the contents of the CHOICES system are given. Chapter 2 focuses on counseling clients, emphasizing the three-step helping process, i.e., preCHOICES, to…

  18. Florida CHOICES Counselor Manual, 1982-1983.

    ERIC Educational Resources Information Center

    Thomas, Glenn R.; And Others

    This manual is intended to acquaint counselors with CHOICES, a computer-assisted career information program. Following an overview of the CHOICES system, and a brief discussion of the usefulness of the program for counselors, the three-step CHOICES process is presented: Step 1, the Initial Interview (pre- CHOICES), involves determining student…

  19. Public School Choice: National Trends and Initiatives.

    ERIC Educational Resources Information Center

    New Jersey State Dept. of Education, Trenton.

    This report offers a framework and conceptual base for a statewide discussion of public school choice. A review of choice activities in other states and an analysis of typical components in a choice program are provided. Organized into four main chapters, the report starts with an explanation of the concept of choice followed by a review of the…

  20. More Choice Isn't Always Better

    ERIC Educational Resources Information Center

    Schuller, Tom

    2012-01-01

    Choice is important to everyone, for one's identity as well as one's material satisfaction. Everyone has choices, but even the head of state's choices are constrained. In recent years choice has risen up the political agenda in the UK. It has become a key component of the drive to reform public services such as health and education. The…

  1. Self-Determination and Choice

    ERIC Educational Resources Information Center

    Wehmeyer, Michael L.; Abery, Brian H.

    2013-01-01

    Promoting self-determination and choice opportunities for people with intellectual and developmental disabilities has become best practice in the field. This article reviews the research and development activities conducted by the authors over the past several decades and provides a synthesis of the knowledge in the field pertaining to efforts to…

  2. Coming Around on School Choice.

    ERIC Educational Resources Information Center

    Viteritti, Joseph P.

    2002-01-01

    Asserts that opponent's predictions that school choice would result in mass exodus of students and a disparate impact on public schools have failed to materialize. Argues that disadvantaged students, especially blacks, in inner-city schools are the principal beneficiaries of voucher programs. (Contains 13 references.) (PKP)

  3. "America's Choice" Taps Profit Motive

    ERIC Educational Resources Information Center

    Trotter, Andrew

    2004-01-01

    In this article, the author features the America's Choice School Design, a school improvement program that has enlisted 547 schools in 16 states in its brand of comprehensive reform, and describes the program's move to loosen its nonprofit moorings and change to a for-profit company. The purpose of the move to for-profit status is to raise capital…

  4. Minnesota's Public School Choice Options.

    ERIC Educational Resources Information Center

    Colopy, Kelly W.; Tarr, Hope C.

    This document presents findings of a study that identified patterns of use among a broad array of open-enrollment options available to elementary and secondary students in Minnesota. During the period 1985-91, the Minnesota legislature passed several pieces of new legislation designed to: (1) increase the educational choices available to students,…

  5. Fresh Perspectives on School Choice

    ERIC Educational Resources Information Center

    Ferrero, David J.

    2004-01-01

    School choice advocacy is dominated by perspectives that reflect a tendency to regard public schooling as a private service commodity. In recent years, numerous works of Anglo-American political philosophy, sociology and legal theory have attempted to restore a conception of public schooling as an institution that cultivates civic virtue.…

  6. No Easy Road to Choice

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2008-01-01

    In the new educational landscape of New Orleans--where public school choice is a fundamental element--pounding the pavement to drum up students has become a familiar pursuit. Proponents say a central idea of the education system that has emerged since Hurricane Katrina hit in 2005 is to provide a diverse array of high-quality school options, with…

  7. Accommodations for Multiple Choice Tests

    ERIC Educational Resources Information Center

    Trammell, Jack

    2011-01-01

    Students with learning or learning-related disabilities frequently struggle with multiple choice assessments due to difficulty discriminating between items, filtering out distracters, and framing a mental best answer. This Practice Brief suggests accommodations and strategies that disability service providers can utilize in conjunction with…

  8. A Choice for the Chosen.

    ERIC Educational Resources Information Center

    Rabkin, Jeremy

    1999-01-01

    Examines reasons for opposition to school-choice programs by the American Jewish Congress and the Anti-Defamation League of B'nai Brith. There is skepticism that more Jewish families would send their children to separate schools, and there is concern that government aid would foster a more religious tone in the country. Suggests that these…

  9. Moral Dimensions of Curriculum Choices.

    ERIC Educational Resources Information Center

    MacMillan, C. J. B.

    This paper argues that just as subject matter is inherently value-laden, educators should not feel trepidation about morally justifying their criteria for choosing curricula to be taught in the classroom. It recommends that true "moral" choices should be made on the bases of relevance to student experiences; moral propriety of subject matter…

  10. Positive Adolescent Choices Training (PACT).

    ERIC Educational Resources Information Center

    Hammond, W. Rodney; And Others

    Positive Adolescent Choices Training (PACT) is a health promotion program providing violence prevention programming targeted at black youth, at high risk for becoming either perpetrators or victims of violence. Conducted by the School of Professional Psychology of Wright State University in Dayton, Ohio, in cooperation with Dayton Public Schools,…

  11. How to make moral choices.

    PubMed

    Chambers, David W

    2011-01-01

    Moral choice is committing to act for what one believes is right and good. It is less about what we know than about defining who we are. Three cases typical of those used in the principles or dilemmas approach to teaching ethics are presented. But they are analyzed using an alternative approach based on seven moral choice heuristics--approaches proven to increase the likelihood of locating the best course of action. The approaches suggested for analyzing moral choice situations include: (a) identify the outcomes of available alternative courses of action; (b) rule out strategies that involve deception, coercion, reneging on promises, collusion, and contempt for others; (c) be authentic (do not deceive yourself); (d) relate to others on a human basis; (e) downplay rational justifications; (f) match the solution to the problem, not the other way around; (g) execute on the best solution, do not hold out for the perfect one; and (h) take action to improve the choice after it has been made. PMID:22416620

  12. Denver Makes a Fairer Choice

    ERIC Educational Resources Information Center

    Teske, Paul; Yettick, Holly; Ely, Todd; Klute, Mary

    2015-01-01

    Denver Public Schools traditional and charter schools combined to create a single system that allowed all students to indicate their school choice preferences, replacing a system of more than 60 different selection processes. The new system also gave families a wealth of information regarding school quality. A study of the new system found it was…

  13. Choices in Cataloging Electronic Journals

    ERIC Educational Resources Information Center

    Leathem, Cecilia A.

    2005-01-01

    Libraries and catalogers face choices in the treatment of the growing collections of electronic journals. Policies issued by CONSER and the Library of Congress allow libraries to edit existing print records to accommodate information pertaining to the electronic versions (single record option) or to create new records for them. The discussion…

  14. Educational Choice and Educational Space

    ERIC Educational Resources Information Center

    Thomson, Kathleen Sonia

    2016-01-01

    This dissertation entitled "Educational choice and educational space" aims to explore the confluence of constructed space and geographic space using a supply-side context for New Zealand's public school system of quasi-open enrollment. In Part I, New Zealand's state and state-integrated school system across four urban areas is analyzed…

  15. Paradigmatic Choices in Evaluation Methodology.

    ERIC Educational Resources Information Center

    Heilman, John G.

    1980-01-01

    The choice between experimental research or process-oriented oriented research as the only valid paradigm of evaluation research is rejected. It is argued that there is a middle ground. Suggestions are made for mixing the two approaches to suit particular research settings. (Author/GK)

  16. Impulsive Choice and Workplace Safety: A New Area of Inquiry for Research in Occupational Settings

    ERIC Educational Resources Information Center

    Reynolds, Brady; Schiffbauer, Ryan M.

    2004-01-01

    A conceptual argument is presented for the relevance of behavior-analytic research on impulsive choice to issues of occupational safety and health. Impulsive choice is defined in terms of discounting, which is the tendency for the value of a commodity to decrease as a function of various parameters (e.g., having to wait or expend energy to receive…

  17. A priori and a posteriori approaches for finding genes of evolutionary interest in non-model species: osmoregulatory genes in the kidney transcriptome of the desert rodent Dipodomys spectabilis (banner-tailed kangaroo rat).

    PubMed

    Marra, Nicholas J; Eo, Soo Hyung; Hale, Matthew C; Waser, Peter M; DeWoody, J Andrew

    2012-12-01

    One common goal in evolutionary biology is the identification of genes underlying adaptive traits of evolutionary interest. Recently next-generation sequencing techniques have greatly facilitated such evolutionary studies in species otherwise depauperate of genomic resources. Kangaroo rats (Dipodomys sp.) serve as exemplars of adaptation in that they inhabit extremely arid environments, yet require no drinking water because of ultra-efficient kidney function and osmoregulation. As a basis for identifying water conservation genes in kangaroo rats, we conducted a priori bioinformatics searches in model rodents (Mus musculus and Rattus norvegicus) to identify candidate genes with known or suspected osmoregulatory function. We then obtained 446,758 reads via 454 pyrosequencing to characterize genes expressed in the kidney of banner-tailed kangaroo rats (Dipodomys spectabilis). We also determined candidates a posteriori by identifying genes that were overexpressed in the kidney. The kangaroo rat sequences revealed nine different a priori candidate genes predicted from our Mus and Rattus searches, as well as 32 a posteriori candidate genes that were overexpressed in kidney. Mutations in two of these genes, Slc12a1 and Slc12a3, cause human renal diseases that result in the inability to concentrate urine. These genes are likely key determinants of physiological water conservation in desert rodents. PMID:22841684

  18. A priori and a posteriori investigations for developing large eddy simulations of multi-species turbulent mixing under high-pressure conditions

    SciTech Connect

    Borghesi, Giulio; Bellan, Josette

    2015-03-15

    , and the filtered species mass fluxes. Improved models were developed based on a scale-similarity approach and were found to perform considerably better than the classical ones. These improved models were also assessed in an a posteriori study. Different combinations of the standard models and the improved ones were tested. At the relatively small Reynolds numbers achievable in DNS and at the relatively small filter widths used here, the standard models for the filtered pressure, the filtered heat flux, and the filtered species fluxes were found to yield accurate results for the morphology of the large-scale structures present in the flow. Analysis of the temporal evolution of several volume-averaged quantities representative of the mixing layer growth, and of the cross-stream variation of homogeneous-plane averages and second-order correlations, as well as of visualizations, indicated that the models performed equivalently for the conditions of the simulations. The expectation is that at the much larger Reynolds numbers and much larger filter widths used in practical applications, the improved models will have much more accurate performance than the standard one.

  19. A Probabilistic, Dynamic, and Attribute-wise Model of Intertemporal Choice

    PubMed Central

    Dai, Junyi; Busemeyer, Jerome R.

    2014-01-01

    Most theoretical and empirical research on intertemporal choice assumes a deterministic and static perspective, leading to the widely adopted delay discounting models. As a form of preferential choice, however, intertemporal choice may be generated by a stochastic process that requires some deliberation time to reach a decision. We conducted three experiments to investigate how choice and decision time varied as a function of manipulations designed to examine the delay duration effect, the common difference effect, and the magnitude effect in intertemporal choice. The results, especially those associated with the delay duration effect, challenged the traditional deterministic and static view and called for alternative approaches. Consequently, various static or dynamic stochastic choice models were explored and fit to the choice data, including alternative-wise models derived from the traditional exponential or hyperbolic discount function and attribute-wise models built upon comparisons of direct or relative differences in money and delay. Furthermore, for the first time, dynamic diffusion models, such as those based on decision field theory, were also fit to the choice and response time data simultaneously. The results revealed that the attribute-wise diffusion model with direct differences, power transformations of objective value and time, and varied diffusion parameter performed the best and could account for all three intertemporal effects. In addition, the empirical relationship between choice proportions and response times was consistent with the prediction of diffusion models and thus favored a stochastic choice process for intertemporal choice that requires some deliberation time to make a decision. PMID:24635188

  20. Diet Selection Fact Sheet - Choices, Choices, Choices- Interpreting the Pasture "Salad Bar"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This fact sheet summarizes some of the current knowledge regarding grazing behavior. A grazing ruminant is presented with a smorgasbord of choices when turned out onto a pasture. However, little is understood on how selection decisions are made by the animal. Grazing behavior research is attempting...

  1. Emotional arousal predicts intertemporal choice.

    PubMed

    Lempert, Karolina M; Johnson, Eli; Phelps, Elizabeth A

    2016-08-01

    People generally prefer immediate rewards to rewards received after a delay, often even when the delayed reward is larger. This phenomenon is known as temporal discounting. It has been suggested that preferences for immediate rewards may be due to their being more concrete than delayed rewards. This concreteness may evoke an enhanced emotional response. Indeed, manipulating the representation of a future reward to make it more concrete has been shown to heighten the reward's subjective emotional intensity, making people more likely to choose it. Here the authors use an objective measure of arousal-pupil dilation-to investigate if emotional arousal mediates the influence of delayed reward concreteness on choice. They recorded pupil dilation responses while participants made choices between immediate and delayed rewards. They manipulated concreteness through time interval framing: delayed rewards were presented either with the date on which they would be received (e.g., "$30, May 3"; DATE condition, more concrete) or in terms of delay to receipt (e.g., "$30, 7 days; DAYS condition, less concrete). Contrary to prior work, participants were not overall more patient in the DATE condition. However, there was individual variability in response to time framing, and this variability was predicted by differences in pupil dilation between conditions. Emotional arousal increased as the subjective value of delayed rewards increased, and predicted choice of the delayed reward on each trial. This study advances our understanding of the role of emotion in temporal discounting. (PsycINFO Database Record PMID:26882337

  2. Quickly making the correct choice.

    PubMed

    Brenner, Eli; Smeets, Jeroen B J

    2015-08-01

    In daily life, unconscious choices guide many of our on-going actions. Such choices need to be made quickly, because the options change as the action progresses. We confirmed that people make reasonable choices when they have to quickly decide between two alternatives, and studied the basis of such decisions. The task was to tap with their finger on as many targets as possible within 2 min. A new target appeared after every tap, sometimes accompanied by a second target that was easier to hit. When there was only one target, subjects had to find the right balance between speed and accuracy. When there were two targets, they also had to choose between them. We examined to what extent subjects switched to the target that was easier to hit when it appeared some time after the original one. Subjects generally switched to the easier target whenever doing so would help them hit more targets within the 2-min session. This was so, irrespective of whether the different delays were presented in separate sessions or were interleaved within one session. Whether or not they switched did not depend on how successful they were at hitting the targets on earlier attempts, but it did depend on the position of the finger at the moment that the easy target appeared. We conclude that people have continuous access to reasonable estimates of how long various movement options would take and of how precise the endpoints are likely to be, given the instantaneous circumstances. PMID:25913027

  3. Street Choice Logit Model for Visitors in Shopping Districts

    PubMed Central

    Kawada, Ko; Yamada, Takashi; Kishimoto, Tatsuya

    2014-01-01

    In this study, we propose two models for predicting people’s activity. The first model is the pedestrian distribution prediction (or postdiction) model by multiple regression analysis using space syntax indices of urban fabric and people distribution data obtained from a field survey. The second model is a street choice model for visitors using multinomial logit model. We performed a questionnaire survey on the field to investigate the strolling routes of 46 visitors and obtained a total of 1211 street choices in their routes. We proposed a utility function, sum of weighted space syntax indices, and other indices, and estimated the parameters for weights on the basis of maximum likelihood. These models consider both street networks, distance from destination, direction of the street choice and other spatial compositions (numbers of pedestrians, cars, shops, and elevation). The first model explains the characteristics of the street where many people tend to walk or stay. The second model explains the mechanism underlying the street choice of visitors and clarifies the differences in the weights of street choice parameters among the various attributes, such as gender, existence of destinations, number of people, etc. For all the attributes considered, the influences of DISTANCE and DIRECTION are strong. On the other hand, the influences of Int.V, SHOPS, CARS, ELEVATION, and WIDTH are different for each attribute. People with defined destinations tend to choose streets that “have more shops, and are wider and lower”. In contrast, people with undefined destinations tend to choose streets of high Int.V. The choice of males is affected by Int.V, SHOPS, WIDTH (positive) and CARS (negative). Females prefer streets that have many shops, and couples tend to choose downhill streets. The behavior of individual persons is affected by all variables. The behavior of people visiting in groups is affected by SHOP and WIDTH (positive). PMID:25379274

  4. Choices in health care: the European experience.

    PubMed

    Thomson, Sarah; Dixon, Anna

    2006-07-01

    This paper examines some policies to increase or restrict consumer choice in western European health systems as regards four decisions: choice between public and private insurance; choice of public insurance fund; choice of first contact care provider and choice of hospital. Choice between public and private insurance is limited and arose for historical reasons in Germany. Owing to significant constraints, few people choose the private option. Choice of public insurance fund tends to be exercised by younger and healthier people, the decision to change fund is mainly associated with price and, despite complex risk adjustment mechanisms, it has led to risk selection by funds. Choice of first contact care provider is widespread in Europe. In countries where choice has traditionally been restricted, reforms aim to make services more accessible and convenient to patients. Reforms to restrict direct access to specialists aim to reduce unnecessary and inappropriate care but have been unpopular with the public and professionals. Patients' take up of choice of hospital has been surprisingly low, given their stated willingness to travel. Only where choice is actively supported in the context of long waiting times is take up higher. The objectives, implementation and impact of policies about choice have varied across western Europe. Culture and embedded norms may be significant in determining the extent to which patients exercise choice. PMID:16824264

  5. Grading School Choice: Evaluating School Choice Programs by the Friedman Gold Standard. School Choice Issues in Depth

    ERIC Educational Resources Information Center

    Enlow, Robert C.

    2008-01-01

    In 2004, The Friedman Foundation for Educational Choice published a report titled "Grading Vouchers: Ranking America's School Choice Programs." Its purpose was to measure every existing school choice program against the gold standard set by Milton and Rose Friedman: that the most effective way to improve K-12 education and thus ensure a stable…

  6. Vegetarian Choices in the Protein Foods Group

    MedlinePlus

    ... Calcium Tips to Making Wise Choices Food Gallery Oils All About Oils How Are Oils Different from Solid Fats? Nutrients and Health Benefits ... Calcium Tips to Making Wise Choices Food Gallery Oils All About Oils How Are Oils Different from ...

  7. Identifying when choice helps: clarifying the relationships between choice making, self-construal, and pain.

    PubMed

    Fox, Jacob; Close, Shane R; Rose, Jason P; Geers, Andrew L

    2016-06-01

    Prior research indicates that making choices before a painful task can sometimes reduce pain. We examined the possibility that independent and interdependent self-construals moderate the effect of choice on pain. Further, we tested between two types of choice: instrumental and non-instrumental. Healthy normotensive undergraduates were randomly assigned to one of three conditions prior to the cold pressor task. Participants in an instrumental choice condition selected which hand to immerse in the water and were told this choice might help reduce their pain. Non-instrumental choice participants selected which hand to immerse but were given no information about potential pain reduction. Control participants were given no choice or additional instructions. Low interdependence individuals reported less pain than high interdependence individuals-but only when given an instrumental choice. These data indicate that not all forms of choice reduce pain and not all individuals benefit from choice. Instead, individuals low in interdependence exhibit pain relief from instrumental choices. PMID:26743202

  8. The Influence of Prior Choices on Current Choice

    PubMed Central

    de la Piedad, Xochitl; Field, Douglas; Rachlin, Howard

    2006-01-01

    Three pigeons chose between random-interval (RI) and tandem, continuous-reinforcement, fixed-interval (crf-FI) reinforcement schedules by pecking either of two keys. As long as a pigeon pecked on the RI key, both keys remained available. If a pigeon pecked on the crf-FI key, then the RI key became unavailable and the crf-FI timer began to time out. With this procedure, once the RI key was initially pecked, the prospective value of both alternatives remained constant regardless of time spent pecking on the RI key without reinforcement (RI waiting time). Despite this constancy, the rate at which pigeons switched from the RI to the crf-FI decreased sharply as RI waiting time increased. That is, prior choices influenced current choice—an exercise effect. It is argued that such influence (independent of reinforcement contingencies) may serve as a sunk-cost commitment device in self-control situations. In a second experiment, extinction was programmed if RI waiting time exceeded a certain value. Rate of switching to the crf-FI first decreased and then increased as the extinction point approached, showing sensitivity to both prior choices and reinforcement contingencies. In a third experiment, crf-FI availability was limited to a brief window during the RI waiting time. When constrained in this way, switching occurred at a high rate regardless of when, during the RI waiting time, the crf-FI became available. PMID:16602373

  9. Risk and Career Choice: Evidence from Turkey

    ERIC Educational Resources Information Center

    Caner, Asena; Okten, Cagla

    2010-01-01

    In this paper, we examine the college major choice decision in a risk and return framework using university entrance exam data from Turkey. Specifically we focus on the choice between majors with low income risk such as education and health and others with riskier income streams. We use a unique dataset that allows us to control for the choice set…

  10. School Choice Acceptance: An Exploratory Explication

    ERIC Educational Resources Information Center

    Koven, Steven G.; Khan, Mobin

    2014-01-01

    School choice is presented by some as a panacea to the challenges facing education in the United States. Acceptance of choice as a solution, however, is far from universal. This article examines two possible contributors to choice adoption: ideology and political culture. Political culture was found to better explain the complex phenomenon of…

  11. The Challenge of Diversity and Choice

    ERIC Educational Resources Information Center

    Glenn, Charles

    2005-01-01

    Schools of equal educational quality need not be identical, and the recent trend toward increased choice and diversity in American schooling has if anything made the system more equitable for children who previously had no choice but to attend poorly performing schools. That is not to say that all forms of school choice are good public policy:…

  12. School Choice as a Bounded Ideal

    ERIC Educational Resources Information Center

    Ben-Porath, Sigal R.

    2009-01-01

    School choice is most often viewed through the lens of provision: most of the debate on the issue searches for desirable ways to offer vouchers, scholarships or other tools that provides choice as a way to achieve equality and/or freedom. This paper focuses on the consumer side of school choice, and utilises behavioural economics as well as…

  13. Choice: The Route to Community Control?

    ERIC Educational Resources Information Center

    Margonis, Frank; Parker, Laurence

    1999-01-01

    While school choice offers inner-city parents a means of educating their children well, it represents further deterioration of society's commitment to educating all students. This paper describes: the push for private school choice; parent choice in context (historical context and failures of desegregation); and segregationist strategies and…

  14. A Framework for Choice Remedy Litigation

    ERIC Educational Resources Information Center

    Bolick, Clint

    2008-01-01

    Although school choice proponents have generally been on the offensive in legislative arenas over the past 2 decades, they have played almost constant defense in the judiciary, seeking to prevent courts from undoing school choice programs. Opponents typically wield state constitutional provisions against school choice programs. Properly construed,…

  15. Discrepancy between Snack Choice Intentions and Behavior

    ERIC Educational Resources Information Center

    Weijzen, Pascalle L. G.; de Graaf, Cees; Dijksterhuis, Garmt B.

    2008-01-01

    Objective: To investigate dietary constructs that affect the discrepancy between intentioned and actual snack choice. Design: Participants indicated their intentioned snack choice from a set of 4 snacks (2 healthful, 2 unhealthful). One week later, they actually chose a snack from the same set. Within 1 week after the actual choice, they completed…

  16. On Becoming an Institution of First Choice.

    ERIC Educational Resources Information Center

    Gelin, Frank; Jardine, Doug

    An overview is provided of the marketing and recruitment efforts designed to make Capilano College (CC) an "institution of first choice" in the minds of its community and prospective students. The presentation by Doug Jardine defines what CC means by and hopes to accomplish by becoming a "first choice" institution, indicating that a "first choice"…

  17. School Choice: Structured through Markets and Morality

    ERIC Educational Resources Information Center

    Lasley, Thomas J., II; Ridenour, Carolyn R.

    2005-01-01

    School choice is increasingly promulgated as a promising education reform policy for failing urban schools, but no solid evidence has yet shown the promise fulfilled. The authors argue that choice based on market theory without a moral center is insufficient. Without a moral foundation, such market-driven choice programs may actually disadvantage…

  18. Understanding cognition, choice, and behavior.

    PubMed

    Corcoran, K J

    1995-09-01

    Bandura (1995) suggests that a "crusade against the causal efficacy of human thought" exists. The present paper disputes that claim, suggesting that the quest which does exist involves an understanding of self-efficacy. Examined are Bandura's shifting definitions of self-efficacy, his misunderstandings of others' work, and implications of some of his attempts to defend the construct. In the remainder of the paper Rotter's Social Learning Theory is discussed as a model of human choice behavior which recognizes the contributions of both cognitive and behavioral traditions within psychology, and has proven to be of great heuristic value. PMID:8576399

  19. Neural Activity Reveals Preferences Without Choices

    PubMed Central

    Smith, Alec; Bernheim, B. Douglas; Camerer, Colin

    2014-01-01

    We investigate the feasibility of inferring the choices people would make (if given the opportunity) based on their neural responses to the pertinent prospects when they are not engaged in actual decision making. The ability to make such inferences is of potential value when choice data are unavailable, or limited in ways that render standard methods of estimating choice mappings problematic. We formulate prediction models relating choices to “non-choice” neural responses and use them to predict out-of-sample choices for new items and for new groups of individuals. The predictions are sufficiently accurate to establish the feasibility of our approach. PMID:25729468

  20. Social determinants of food choice.

    PubMed

    Shepherd, R

    1999-11-01

    Food choice is influenced by a large number of factors, including social and cultural factors. One method for trying to understand the impact of these factors is through the study of attitudes. Research is described which utilizes social psychological attitude models of attitude-behaviour relationships, in particular the Theory of Planned Behaviour. This approach has shown good prediction of behaviour, but there are a number of possible extensions to this basic model which might improve its utility. One such extension is the inclusion of measures of moral concern, which have been found to be important both for the choice of genetically-modified foods and also for foods to be eaten by others. It has been found to be difficult to effect dietary change, and there are a number of insights from social psychology which might address this difficulty. One is the phenomenon of optimistic bias, where individuals believe themselves to be at less risk from various hazards than the average person. This effect has been demonstrated for nutritional risks, and this might lead individuals to take less note of health education messages. Another concern is that individuals do not always have clear-cut attitudes, but rather can be ambivalent about food and about healthy eating. It is important, therefore, to have measures for this ambivalence, and an understanding of how it might impact on behaviour. PMID:10817147

  1. Multiplexed modulation of behavioral choice

    PubMed Central

    Palmer, Chris R.; Barnett, Megan N.; Copado, Saul; Gardezy, Fred; Kristan, William B.

    2014-01-01

    Stimuli in the environment, as well as internal states, influence behavioral choice. Of course, animals are often exposed to multiple external and internal factors simultaneously, which makes the ultimate determinants of behavior quite complex. We observed the behavioral responses of European leeches, Hirudo verbana, as we varied one external factor (surrounding water depth) with either another external factor (location of tactile stimulation along the body) or an internal factor (body distention following feeding). Stimulus location proved to be the primary indicator of behavioral response. In general, anterior stimulation produced shortening behavior, midbody stimulation produced local bending, and posterior stimulation usually produced either swimming or crawling but sometimes a hybrid of the two. By producing a systematically measured map of behavioral responses to body stimulation, we found wide areas of overlap between behaviors. When we varied the surrounding water depth, this map changed significantly, and a new feature – rotation of the body along its long axis prior to swimming – appeared. We found additional interactions between water depth and time since last feeding. A large blood meal initially made the animals crawl more and swim less, an effect that was attenuated as water depth increased. The behavioral map returned to its pre-feeding form after approximately 3 weeks as the leeches digested their blood meal. In summary, we found multiplexed impacts on behavioral choice, with the map of responses to tactile stimulation modified by water depth, which itself modulated the impact that feeding had on the decision to swim or crawl. PMID:24902753

  2. Choice as a Global Language in Local Practice: A Mixed Model of School Choice in Taiwan

    ERIC Educational Resources Information Center

    Mao, Chin-Ju

    2015-01-01

    This paper uses school choice policy as an example to demonstrate how local actors adopt, mediate, translate, and reformulate "choice" as neo-liberal rhetoric informing education reform. Complex processes exist between global policy about school choice and the local practice of school choice. Based on the theoretical sensibility of…

  3. Supergranular Parameters

    NASA Astrophysics Data System (ADS)

    Udayashankar, Paniveni

    2016-07-01

    I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.

  4. A Simplified Model of Choice Behavior under Uncertainty

    PubMed Central

    Lin, Ching-Hung; Lin, Yu-Kai; Song, Tzu-Jiun; Huang, Jong-Tsun; Chiu, Yao-Chu

    2016-01-01

    The Iowa Gambling Task (IGT) has been standardized as a clinical assessment tool (Bechara, 2007). Nonetheless, numerous research groups have attempted to modify IGT models to optimize parameters for predicting the choice behavior of normal controls and patients. A decade ago, most researchers considered the expected utility (EU) model (Busemeyer and Stout, 2002) to be the optimal model for predicting choice behavior under uncertainty. However, in recent years, studies have demonstrated that models with the prospect utility (PU) function are more effective than the EU models in the IGT (Ahn et al., 2008). Nevertheless, after some preliminary tests based on our behavioral dataset and modeling, it was determined that the Ahn et al. (2008) PU model is not optimal due to some incompatible results. This study aims to modify the Ahn et al. (2008) PU model to a simplified model and used the IGT performance of 145 subjects as the benchmark data for comparison. In our simplified PU model, the best goodness-of-fit was found mostly as the value of α approached zero. More specifically, we retested the key parameters α, λ, and A in the PU model. Notably, the influence of the parameters α, λ, and A has a hierarchical power structure in terms of manipulating the goodness-of-fit in the PU model. Additionally, we found that the parameters λ and A may be ineffective when the parameter α is close to zero in the PU model. The present simplified model demonstrated that decision makers mostly adopted the strategy of gain-stay loss-shift rather than foreseeing the long-term outcome. However, there are other behavioral variables that are not well revealed under these dynamic-uncertainty situations. Therefore, the optimal behavioral models may not have been found yet. In short, the best model for predicting choice behavior under dynamic-uncertainty situations should be further evaluated. PMID:27582715

  5. A Simplified Model of Choice Behavior under Uncertainty.

    PubMed

    Lin, Ching-Hung; Lin, Yu-Kai; Song, Tzu-Jiun; Huang, Jong-Tsun; Chiu, Yao-Chu

    2016-01-01

    The Iowa Gambling Task (IGT) has been standardized as a clinical assessment tool (Bechara, 2007). Nonetheless, numerous research groups have attempted to modify IGT models to optimize parameters for predicting the choice behavior of normal controls and patients. A decade ago, most researchers considered the expected utility (EU) model (Busemeyer and Stout, 2002) to be the optimal model for predicting choice behavior under uncertainty. However, in recent years, studies have demonstrated that models with the prospect utility (PU) function are more effective than the EU models in the IGT (Ahn et al., 2008). Nevertheless, after some preliminary tests based on our behavioral dataset and modeling, it was determined that the Ahn et al. (2008) PU model is not optimal due to some incompatible results. This study aims to modify the Ahn et al. (2008) PU model to a simplified model and used the IGT performance of 145 subjects as the benchmark data for comparison. In our simplified PU model, the best goodness-of-fit was found mostly as the value of α approached zero. More specifically, we retested the key parameters α, λ, and A in the PU model. Notably, the influence of the parameters α, λ, and A has a hierarchical power structure in terms of manipulating the goodness-of-fit in the PU model. Additionally, we found that the parameters λ and A may be ineffective when the parameter α is close to zero in the PU model. The present simplified model demonstrated that decision makers mostly adopted the strategy of gain-stay loss-shift rather than foreseeing the long-term outcome. However, there are other behavioral variables that are not well revealed under these dynamic-uncertainty situations. Therefore, the optimal behavioral models may not have been found yet. In short, the best model for predicting choice behavior under dynamic-uncertainty situations should be further evaluated. PMID:27582715

  6. Relationship between dual-domain parameters and practical characterization data.

    PubMed

    Flach, Gregory P

    2012-01-01

    Dual-domain solute transport models produce significantly improved agreement to observations compared to single-domain (advection-dispersion) models when used in an a posteriori data fitting mode. However, the use of dual-domain models in a general predictive manner has been a difficult and persistent challenge, particularly at field-scale where characterization of permeability and flow is inherently limited. Numerical experiments were conducted in this study to better understand how single-rate mass transfer parameters vary with aquifer attributes and contaminant exposure. High-resolution reference simulations considered 30 different scenarios involving variations in permeability distribution, flow field, mass transfer timescale, and contaminant exposure time. Optimal dual-domain transport parameters were empirically determined by matching to breakthrough curves from the high-resolution simulations. Numerical results show that mobile porosity increases with lower permeability contrast/variance, smaller spatial correlation length, lower connectivity of high-permeability zones, and flow transverse to strata. A nonzero non-participating porosity improves empirical fitting, and becomes larger for flow aligned with strata, smaller diffusion coefficient, and larger spatial correlation length. The non-dimensional mass transfer coefficient or Damkohler number tends to be close to 1.0 and decrease with contaminant exposure time, in agreement with prior studies. The best empirical fit is generally achieved with a combination of macrodispersion and first-order mass transfer. Quantitative prediction of ensemble-average dual-domain parameters as a function of measurable aquifer attributes proved only marginally successful. PMID:21696389

  7. Psychophysics of time perception and intertemporal choice models

    NASA Astrophysics Data System (ADS)

    Takahashi, Taiki; Oono, Hidemi; Radford, Mark H. B.

    2008-03-01

    Intertemporal choice and psychophysics of time perception have been attracting attention in econophysics and neuroeconomics. Several models have been proposed for intertemporal choice: exponential discounting, general hyperbolic discounting (exponential discounting with logarithmic time perception of the Weber-Fechner law, a q-exponential discount model based on Tsallis's statistics), simple hyperbolic discounting, and Stevens' power law-exponential discounting (exponential discounting with Stevens' power time perception). In order to examine the fitness of the models for behavioral data, we estimated the parameters and AICc (Akaike Information Criterion with small sample correction) of the intertemporal choice models by assessing the points of subjective equality (indifference points) at seven delays. Our results have shown that the orders of the goodness-of-fit for both group and individual data were [Weber-Fechner discounting (general hyperbola) > Stevens' power law discounting > Simple hyperbolic discounting > Exponential discounting], indicating that human time perception in intertemporal choice may follow the Weber-Fechner law. Indications of the results for neuropsychopharmacological treatments of addiction and biophysical processing underlying temporal discounting and time perception are discussed.

  8. Suboptimal Choice in Pigeons: Stimulus Value Predicts Choice over Frequencies.

    PubMed

    Smith, Aaron P; Bailey, Alexandria R; Chow, Jonathan J; Beckmann, Joshua S; Zentall, Thomas R

    2016-01-01

    Pigeons have shown suboptimal gambling-like behavior when preferring a stimulus that infrequently signals reliable reinforcement over alternatives that provide greater reinforcement overall. As a mechanism for this behavior, recent research proposed that the stimulus value of alternatives with more reliable signals for reinforcement will be preferred relatively independently of their frequencies. The present study tested this hypothesis using a simplified design of a Discriminative alternative that, 50% of the time, led to either a signal for 100% reinforcement or a blackout period indicative of 0% reinforcement against a Nondiscriminative alternative that always led to a signal that predicted 50% reinforcement. Pigeons showed a strong preference for the Discriminative alternative that remained despite reducing the frequency of the signal for reinforcement in subsequent phases to 25% and then 12.5%. In Experiment 2, using the original design of Experiment 1, the stimulus following choice of the Nondiscriminative alternative was increased to 75% and then to 100%. Results showed that preference for the Discriminative alternative decreased only when the signals for reinforcement for the two alternatives predicted the same probability of reinforcement. The ability of several models to predict this behavior are discussed, but the terminal link stimulus value offers the most parsimonious account of this suboptimal behavior. PMID:27441394

  9. Suboptimal Choice in Pigeons: Stimulus Value Predicts Choice over Frequencies

    PubMed Central

    Bailey, Alexandria R.; Chow, Jonathan J.; Beckmann, Joshua S.; Zentall, Thomas R.

    2016-01-01

    Pigeons have shown suboptimal gambling-like behavior when preferring a stimulus that infrequently signals reliable reinforcement over alternatives that provide greater reinforcement overall. As a mechanism for this behavior, recent research proposed that the stimulus value of alternatives with more reliable signals for reinforcement will be preferred relatively independently of their frequencies. The present study tested this hypothesis using a simplified design of a Discriminative alternative that, 50% of the time, led to either a signal for 100% reinforcement or a blackout period indicative of 0% reinforcement against a Nondiscriminative alternative that always led to a signal that predicted 50% reinforcement. Pigeons showed a strong preference for the Discriminative alternative that remained despite reducing the frequency of the signal for reinforcement in subsequent phases to 25% and then 12.5%. In Experiment 2, using the original design of Experiment 1, the stimulus following choice of the Nondiscriminative alternative was increased to 75% and then to 100%. Results showed that preference for the Discriminative alternative decreased only when the signals for reinforcement for the two alternatives predicted the same probability of reinforcement. The ability of several models to predict this behavior are discussed, but the terminal link stimulus value offers the most parsimonious account of this suboptimal behavior. PMID:27441394

  10. Behavioural social choice: a status report

    PubMed Central

    Regenwetter, Michel; Grofman, Bernard; Popova, Anna; Messner, William; Davis-Stober, Clintin P.; Cavagnaro, Daniel R.

    2008-01-01

    Behavioural social choice has been proposed as a social choice parallel to seminal developments in other decision sciences, such as behavioural decision theory, behavioural economics, behavioural finance and behavioural game theory. Behavioural paradigms compare how rational actors should make certain types of decisions with how real decision makers behave empirically. We highlight that important theoretical predictions in social choice theory change dramatically under even minute violations of standard assumptions. Empirical data violate those critical assumptions. We argue that the nature of preference distributions in electorates is ultimately an empirical question, which social choice theory has often neglected. We also emphasize important insights for research on decision making by individuals. When researchers aggregate individual choice behaviour in laboratory experiments to report summary statistics, they are implicitly applying social choice rules. Thus, they should be aware of the potential for aggregation paradoxes. We hypothesize that such problems may substantially mar the conclusions of a number of (sometimes seminal) papers in behavioural decision research. PMID:19073478

  11. Nuclear position dictates DNA repair pathway choice

    PubMed Central

    Lemaître, Charlène; Grabarz, Anastazja; Tsouroula, Katerina; Andronov, Leonid; Furst, Audrey; Pankotai, Tibor; Heyer, Vincent; Rogier, Mélanie; Attwood, Kathleen M.; Kessler, Pascal; Dellaire, Graham; Klaholz, Bruno; Reina-San-Martin, Bernardo; Soutoglou, Evi

    2014-01-01

    Faithful DNA repair is essential to avoid chromosomal rearrangements and promote genome integrity. Nuclear organization has emerged as a key parameter in the formation of chromosomal translocations, yet little is known as to whether DNA repair can efficiently occur throughout the nucleus and whether it is affected by the location of the lesion. Here, we induce DNA double-strand breaks (DSBs) at different nuclear compartments and follow their fate. We demonstrate that DSBs induced at the nuclear membrane (but not at nuclear pores or nuclear interior) fail to rapidly activate the DNA damage response (DDR) and repair by homologous recombination (HR). Real-time and superresolution imaging reveal that DNA DSBs within lamina-associated domains do not migrate to more permissive environments for HR, like the nuclear pores or the nuclear interior, but instead are repaired in situ by alternative end-joining. Our results are consistent with a model in which nuclear position dictates the choice of DNA repair pathway, thus revealing a new level of regulation in DSB repair controlled by spatial organization of DNA within the nucleus. PMID:25366693

  12. Basic and applied research on choice responding.

    PubMed Central

    Fisher, W W; Mazur, J E

    1997-01-01

    Choice responding refers to the manner in which individuals allocate their time or responding among available response options. In this article, we first review basic investigations that have identified and examined variables that influence choice responding, such as response effort and reinforcement rate, immediacy, and quality. We then describe recent bridge and applied studies that illustrate how the results of basic research on choice responding can help to account for human behavior in natural environments and improve clinical assessments and interventions. PMID:9316255

  13. Letter: Contraceptive choice and cervical cytology.

    PubMed

    Leppaluoto, P

    1974-02-15

    In the evaluation of biological potentials of contraceptives in the genesis of cervical cancer, cytology seems to have been given due attention while information on the clinical condition and specific treatment of the target organ, the cervix, is repeatedly neglected. "Cancer does not develop in a healthy cervix" is an old dogma derived from impressions gained by clinical examination of the organ. This concept is supported by epidemiologic studies indicating that cancer is extremely rare in cervices restored to a normal condition by cauterization. It may be postulated that this type of treatment destroys the permissive target cells of the cervix, thus indirectly rendering possible coitus-associated and contraceptive-associated(?) mutagen(s) invalid. Also, in comparative studies, an evaluation should be made of the significance of a higher incidence of cervical ectopy reported in women receiving oral hormonal contraceptives. The importance of ectopy in the genesis of cervical malignancy has been derived from the presumption that permissive cervical cells are thus created and exposed to vaginal contents which may harbor the mutagens(s). Therefore, it would seem not only desirable but imperative to include the neglected parameters of clinical condition and of specific treatment (both past and present) of the uterine cervix in the structure of studies like the recent one in this Journal on "Contraceptive choice and cervical cytology", by Drs. Shulman and Merritt. Still another parameter which might prove to be of significance is the predominant type of vaginal flora, which can be assessed readily in the routine examination of Papanicolaou smears. It may be that vaginal contents, which would seem to be somewhat different in wearers of the intrauterine contraceptive device as compared to "pill" users, might play a part in the advent of cervical malignancy as a medium of or for coitus-associated mutagens(s). PMID:4855868

  14. Consumers, health insurance and dominated choices.

    PubMed

    Sinaiko, Anna D; Hirth, Richard A

    2011-03-01

    We analyze employee health plan choices when the choice set offered by their employer includes a dominated plan. During our study period, one-third of workers were enrolled in the dominated plan. Some may have selected the plan before it was dominated and then failed to switch out of it. However, a substantial number actively chose the dominated plan when they had an unambiguously better choice. These results suggest limitations in the ability of health reform based solely on consumer choice to achieve efficient outcomes and that implementation of health reform should anticipate, monitor and account for this consumer behavior. PMID:21300414

  15. Embedding parameters for Quantum Annealing

    NASA Astrophysics Data System (ADS)

    Venturelli, Davide

    Many optimization problems are defined on highly connected graphs and many interesting physical spin-glass systems are featuring long-range interactions. One method to solve for the optimum/ground state is quantum annealing (QA). Most architectures for QA devices, manufactured or proposed, are based on optimizing Hamiltonians having spins connected in a non-complete graph, with nodes with a small maximum degree, compared to the requirements. To overcome this limitation 'embedding' is employed: the native graph is 'tiled' with ferromagnetic chains of spins that now are meant to represent the logical binary variables. While it is known how the strength of the ferromagnetic bonds can ensure that the classical Ising ground state of the embedded system can be univocally mapped to the ground state of the original system, there is very little study on the impact of these parameters on QA. Programmers have taken conservative choices for the parameters and the common practices can be improved. Starting from the physics of connected ferromagnetic Ising chains, we will review several parameter choices and discuss previous and new results obtained on the D-Wave 2X machine, on carefully designed problems that allow to isolate and evaluate the role of connectivity in embedded systems.

  16. The effect of alcohol hangover on choice response time.

    PubMed

    Grange, James A; Stephens, Richard; Jones, Kate; Owen, Lauren

    2016-07-01

    The effect of alcohol hangover on cognitive processing has received little attention. We explored the effect of alcohol hangover on choice response time (RT), a dominant dependent variable (DV) in cognitive research. Prior research of the effect of hangover on RT has produced mixed findings; all studies reviewed relied exclusively on estimates of central tendency (e.g. mean RT), which has limited information value. Here we present novel analytical methods by going beyond mean RT analysis. Specifically, we examined performance in hangover conditions (n=31) across the whole RT distribution by fitting ex-Gaussian models to participant data, providing a formal description of the RT distribution. This analysis showed detriments to performance under hangover conditions at the slower end of the RT distribution and increased RT variance under hangover conditions. We also fitted an explicit mathematical process model of choice RT - the diffusion model - which estimates parameters reflecting psychologically-meaningful processes underlying choice RT. This analysis showed that hangover reduced information processing efficiency during response selection, and increased response caution; changes in these parameters reflect hangover affecting core decisional-components of RT performance. The implications of the data as well as the methods used for hangover research are discussed. PMID:27166364

  17. Teen Choice of Inwood House.

    PubMed

    1994-05-01

    The Teen Choice Program in New York City was described and the outcome of the program evaluation was reported. Teen Choice is a school based sex education and pregnancy prevention program run by trained social workers. The aim is to provide information, counseling, and referrals on a range of issues relating to sexuality. The program is elective and meets during a regularly scheduled gym period for one or two semesters from the 7th to the 12th grades. There are single sex and coeducational classes. The program aim is to change attitudes toward birth control, to change risky sexual behavior, such as unprotected coitus, to offer accurate knowledge about contraception, and to prevent unplanned pregnancies. Abstinence is encouraged, but for those sexually experienced, there is attention to responsible and reliable use of contraception. Program methods include small group discussion, individual counseling, and classroom discussion. Topics of discussion range from sexuality issues and birth control to values clarification and peer pressure. Small groups may discuss human sexual growth, relationship formation, family life, responsibility to self and others, consequences of teenage pregnancy, and social and cultural peer pressures. Girls are encouraged to assume more assertive and less reactive roles. Communication skills are reinforced in respectful exchanges of personal views and questions. Differentiating facts and issues is a primary focus. A question about when an individual first had sex would be redirected to asking about the appropriate age to first have sex. Respect for privacy helps to build students confidence in the program. A longitudinal evaluation conducted between 1984 and 1987 found that the program was effective in reaching and recruiting high risk adolescents. Students left the program with increased knowledge about contraception, more mature and responsible attitudes about the use of birth control, and reduced frequency of unprotected coitus. Boys were

  18. Parameter Estimation and Model Selection in Computational Biology

    PubMed Central

    Lillacci, Gabriele; Khammash, Mustafa

    2010-01-01

    A central challenge in computational modeling of biological systems is the determination of the model parameters. Typically, only a fraction of the parameters (such as kinetic rate constants) are experimentally measured, while the rest are often fitted. The fitting process is usually based on experimental time course measurements of observables, which are used to assign parameter values that minimize some measure of the error between these measurements and the corresponding model prediction. The measurements, which can come from immunoblotting assays, fluorescent markers, etc., tend to be very noisy and taken at a limited number of time points. In this work we present a new approach to the problem of parameter selection of biological models. We show how one can use a dynamic recursive estimator, known as extended Kalman filter, to arrive at estimates of the model parameters. The proposed method follows. First, we use a variation of the Kalman filter that is particularly well suited to biological applications to obtain a first guess for the unknown parameters. Secondly, we employ an a posteriori identifiability test to check the reliability of the estimates. Finally, we solve an optimization problem to refine the first guess in case it should not be accurate enough. The final estimates are guaranteed to be statistically consistent with the measurements. Furthermore, we show how the same tools can be used to discriminate among alternate models of the same biological process. We demonstrate these ideas by applying our methods to two examples, namely a model of the heat shock response in E. coli, and a model of a synthetic gene regulation system. The methods presented are quite general and may be applied to a wide class of biological systems where noisy measurements are used for parameter estimation or model selection. PMID:20221262

  19. Dopaminergic function and intertemporal choice.

    PubMed

    Joutsa, J; Voon, V; Johansson, J; Niemelä, S; Bergman, J; Kaasinen, V

    2015-01-01

    The discounting of delayed rewards, also known as temporal or delay discounting, is intrinsic to everyday decisions and can be impaired in pathological states such as addiction disorders. Preclinical and human studies suggest a role for dopaminergic function in temporal discounting but this relationship has not yet been verified using molecular imaging of the living human brain. Here, we evaluated dopaminergic function in temporal discounting using positron emission tomography (PET) with two different dopaminergic ligands assessing three populations in whom temporal discounting has been shown to be impaired. First, we show using [11C]raclopride PET that in pathological gamblers, greater temporal discounting correlates with decreased ventral striatal binding potential, convergent with translational findings of lower nucleus accumbens D2/D3 receptor density in high-impulsive rodents. Temporal discounting also correlates with lower ventral striatal dopamine release in response to high-reward magnitude suggesting that dopamine-mediated devaluation of larger delayed rewards may drive choice preferences. Second, we show using [18F]fluorodopa PET that in Parkinson's disease, temporal discounting correlates with greater left caudate dopaminergic terminal function. Finally, in subjects with Parkinson's disease and dopamine medication-induced behavioral addictions, temporal discounting is further correlated with greater dopaminergic terminal function in the anterior putamen. These findings provide insights into the relationship between striatal dopamine function and temporal discounting, and its potential role in pathological disorders and mechanisms underlying treatment interventions. PMID:25562841

  20. Estimating insulin sensitivity from glucose levels only: Use of a non-linear mixed effects approach and maximum a posteriori (MAP) estimation.

    PubMed

    Yates, James W T; Watson, Edmund M

    2013-02-01

    Insulin Sensitivity is an important parameter for the management of Diabetes. It can be derived for a particular patient using data derived from some glucose challenge tests using measured glucose and insulin levels at various times. Whilst a useful approach, deriving insulin sensitivities to inform insulin dosing in other settings such as Intensive Care Units can be more challenging - especially as insulin levels have to be assayed in a laboratory, not at the bedside. This paper investigates an approach to measure insulin sensitivity from glucose levels only. Estimates of mean and between individual parameter variances are used to derive conditional estimates of insulin sensitivity. The method is demonstrated to perform reasonably well, with conditional estimates comparing well with estimates derived from insulin data as well. PMID:22244505

  1. Expected utility theory and risky choices with health outcomes.

    PubMed

    Hellinger, F J

    1989-03-01

    Studies of people's attitude towards risk in the health sector often involve a comparison of the desirability of alternative medical treatments. Since the outcome of a medical treatment cannot be known with certainty, patients and physicians must make a choice that involves risk. Each medical treatment may be characterized as a gamble (or risky option) with a set of outcomes and associated probabilities. Expected utility theory (EUT) is the standard method to predict people's choices under uncertainty. The author presents the results of a survey that suggests people are very risk averse towards gambles involving health-related outcomes. The survey also indicates that there is significant variability in the risk attitudes across individuals for any given gamble and that there is significant variability in the risk attitudes of a given individual across gambles. The variability of risk attitudes of a given individual suggests that risk attitudes are not absolute but are functions of the parameters in the gamble. PMID:2927183

  2. Quantification of drug choice with the generalized matching law in rhesus monkeys.

    PubMed

    Koffarnus, Mikhail N; Woods, James H

    2008-03-01

    The generalized matching law provides precise descriptions of choice, but has not been used to characterize choice between different doses of drugs or different classes of drugs. The current study examined rhesus monkeys' drug self-administration choices between identical drug doses, different doses, different drugs (cocaine, remifentanil, and methohexital), and between drug and drug-paired stimuli. The bias parameter of the generalized matching law was used to quantify preference for one reinforcer over another. Choice between identical drug doses yielded undermatching. Choices between 0.3 microg/kg/injection remifentanil and either 0.1 microg/kg/injection remifentanil or saline plus drug-paired stimuli revealed bias for the 0.3 microg/kg/injection dose. Choice was relatively insensitive to differences in random interval schedule value when one reinforcer was replaced with drug-paired stimulus presentations. Bias for 0.3 microg/kg/injection remifentanil over 10 microg/kg/injection cocaine was seen in one subject, and indifference was generally observed between 0.1 microg/kg/injection remifentanil and 56 microg/kg/injection cocaine and between 30 microg/kg/injection cocaine and 320 microg/kg/injection methohexital. These findings suggest the bias parameter may be useful in quantitatively measuring level of preference, which would be an advantage over concurrent FR procedures that often result in exclusive choice. PMID:18422019

  3. Reconstruction of signals with unknown spectra in information field theory with parameter uncertainty

    SciTech Connect

    Ensslin, Torsten A.; Frommert, Mona

    2011-05-15

    The optimal reconstruction of cosmic metric perturbations and other signals requires knowledge of their power spectra and other parameters. If these are not known a priori, they have to be measured simultaneously from the same data used for the signal reconstruction. We formulate the general problem of signal inference in the presence of unknown parameters within the framework of information field theory. To solve this, we develop a generic parameter-uncertainty renormalized estimation (PURE) technique. As a concrete application, we address the problem of reconstructing Gaussian signals with unknown power-spectrum with five different approaches: (i) separate maximum-a-posteriori power-spectrum measurement and subsequent reconstruction, (ii) maximum-a-posteriori reconstruction with marginalized power-spectrum, (iii) maximizing the joint posterior of signal and spectrum, (iv) guessing the spectrum from the variance in the Wiener-filter map, and (v) renormalization flow analysis of the field-theoretical problem providing the PURE filter. In all cases, the reconstruction can be described or approximated as Wiener-filter operations with assumed signal spectra derived from the data according to the same recipe, but with differing coefficients. All of these filters, except the renormalized one, exhibit a perception threshold in case of a Jeffreys prior for the unknown spectrum. Data modes with variance below this threshold do not affect the signal reconstruction at all. Filter (iv) seems to be similar to the so-called Karhune-Loeve and Feldman-Kaiser-Peacock estimators for galaxy power spectra used in cosmology, which therefore should also exhibit a marginal perception threshold if correctly implemented. We present statistical performance tests and show that the PURE filter is superior to the others, especially if the post-Wiener-filter corrections are included or in case an additional scale-independent spectral smoothness prior can be adopted.

  4. Instructional Innovation, School Choice, and Student Achievement

    ERIC Educational Resources Information Center

    Berends, Mark; Penaloza, Roberto V.; Cannata, Marisa; Goldring, Ellen

    2009-01-01

    There is limited empirical research about innovation in various types of schools of choice, although viable choice policies tend to assume clear differentiation amongst schools. Innovation can be conceptualized in many ways and takes place at multiple levels of the school organization. Schools can innovate in terms of the roles and responsibility…

  5. Making the Most of Multiple Choice

    ERIC Educational Resources Information Center

    Brookhart, Susan M.

    2015-01-01

    Multiple-choice questions draw criticism because many people perceive they test only recall or atomistic, surface-level objectives and do not require students to think. Although this can be the case, it does not have to be that way. Susan M. Brookhart suggests that multiple-choice questions are a useful part of any teacher's questioning repertoire…

  6. Informed Consumer Choice in Community Rehabilitation Programs

    ERIC Educational Resources Information Center

    Hagen-Foley, Debra L.; Rosenthal, David A.; Thomas, Dale F.

    2005-01-01

    This study investigated consumer and staff member perceptions regarding the extent of consumer choice and participatory planning in community-based rehabilitation programs (CRPs) and the relationship between these elements, satisfaction, and outcomes. Consumers reported moderate to high levels of choice in services and employment goals, and…

  7. An Update on School Choice in Canada

    ERIC Educational Resources Information Center

    Holmes, Mark

    2008-01-01

    This article gives an update on school choice in Canada. Currently, school choice in Canada is stable. Provincialism, in both senses of the word, is a major factor in Canadian political life. There is no contradiction between Ontario's recent electoral rejection of the extension of funding to non-Catholic religious schools, and the strong support…

  8. Personality Differences in Career Choice Patterns

    ERIC Educational Resources Information Center

    Borges, Nicole J.; Roth, Karl S.; Seibel, Hugo R.

    2004-01-01

    Vocational identity is an important construct for physician career development. Physician vocational development has been grouped into three tasks (crystallization, specification, and implementation) pertaining to career choice and specialty choice (1) In defining the construct of vocational identity, it has been suggested that the relation…

  9. A Look at School Choice in Spain.

    ERIC Educational Resources Information Center

    Villarroya, Ana

    2002-01-01

    Investigated how school choice policies implemented by the Spanish government (introduction of a right to enroll in any publicly-funded school and establishment of a system of finance where user choice directs government funds) have functioned in practice. Data on the Catalan community collected from a group of school inspectors indicated that…

  10. Career Choice Anxiety, Coping, and Perceived Control.

    ERIC Educational Resources Information Center

    Weinstein, Faye M.; Healy, Charles C.; Ender, Philip B.

    2002-01-01

    Presents a study exploring whether perceived control moderates the relation between coping with career indecision and choice anxiety among women in low-level jobs. Results revealed that perceived control interacted with problem-focused coping to increase accountable variance in choice anxiety. Discusses implications for interventions with women in…

  11. Factors Influencing Career Choice among Police Recruits

    ERIC Educational Resources Information Center

    Cole, Bryan

    2012-01-01

    This quantitative, non-experimental study examined the career choice factors of 154 (n = 154) police recruits to determine a correlation of age group generation to the five career choice factors presented in the Sibson Reward of Work Model. Law enforcement agencies faced a shortage of viable candidates to fill vacant positions. While extensive…

  12. Work Values and College Major Choice

    ERIC Educational Resources Information Center

    Balsamo, Michela; Lauriola, Marco; Saggino, Aristide

    2013-01-01

    Our study sought to clarify the nature of the known individual differences in work values associated with academic college major choice, specifically the question whether these precede or follow the choice of an academic major. To rule out environmental influences during academic study, group differences in five value orientations were evaluated…

  13. School Choice: What Guides an Adolescent's Decision?

    ERIC Educational Resources Information Center

    Matson, Barbara Smith

    Choice in education gained popularity as a means by which families can become involved in the education of their children. This case study addresses how the interests, needs, and objectives of secondary school students, and their parents as reported by the students, resulted in the choice between two high schools in a suburban district with a…

  14. 45 CFR 98.30 - Parental choice.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Parental choice. 98.30 Section 98.30 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Program Operations (Child Care Services)-Parental Rights and Responsibilities § 98.30 Parental choice. (a) The parent or parents of an eligible child...

  15. Democratic Education and School Choice Revisited

    ERIC Educational Resources Information Center

    Paquette, Jerry

    2005-01-01

    This article features the author's reply to John Coons's "Dodging Democracy: The Educator's Flight from the Specter of Choice." First, he wants to thank Coons for his thoughtful and thought-provoking reply to "Public Funding for 'Private' Education: The Equity Challenge of Enhanced Choice." So thought provoking, in fact, did the author find…

  16. Two Philosophical Errors Concerning School Choice.

    ERIC Educational Resources Information Center

    Brighouse, Harry

    1997-01-01

    Argues, in contrast to David Hargreaves, that libertarianism implies a mild presumption against school choice, and that notions of common good are significant to educational decision making only when deciding between sets of institutions that perform equally well at delivering their obligations. Links these issues to questions about school choice.…

  17. Constructive Multiple-Choice Testing System

    ERIC Educational Resources Information Center

    Park, Jooyong

    2010-01-01

    The newly developed computerized Constructive Multiple-choice Testing system is introduced. The system combines short answer (SA) and multiple-choice (MC) formats by asking examinees to respond to the same question twice, first in the SA format, and then in the MC format. This manipulation was employed to collect information about the two…

  18. Introducing Nonlinear Pricing into Consumer Choice Theory.

    ERIC Educational Resources Information Center

    DeSalvo, Joseph S.; Huq, Mobinul

    2002-01-01

    Describes and contrasts nonlinear and linear pricing in consumer choice theory. Discusses the types of nonlinear pricing: block-declining tariff, two-part tariff, three-part tariff, and quality discounts or premia. States that understanding nonlinear pricing enhances student comprehension of consumer choice theory. Suggests teaching the concept in…

  19. Food choice: beyond the chemical content.

    PubMed

    Franchi, Maura

    2012-03-01

    How are food choices formulated? Which are the factors that mostly affect food choice? These questions are crucially important both for efforts in food innovation and for institutions that face consequences and costs of diets that are harmful to human health and to the environment. On these matters, several reports have been developed following the angel of various disciplines, focusing on the analysis of the factors affecting food choices. Large-scale research on consumption behaviours has neither stopped the growing number of unsuccessful products entering the market, nor provided adequate support for institutions that are taking elaborate actions towards promoting health-orientated behaviours. These preliminary remarks highlight the need to think about the approaches and categories with which research programmes on food choices should be updated. This article discusses the reasons why food choices are determined by beliefs and identity, are conditioned by social images that influence preferences by indicating to individuals what foods are 'good' and 'right'; belong to the field of individual choice, and therefore, cannot be assimilated into medical prescriptions or merely reduced to a question of rules. Taste involves beliefs and identity as well as perceptions. This is why it has to be analyzed as a cultural and relational object. This paper aims to explore the complex mix of influences on food choice stressing that food choice is a matter of identity. PMID:22059432

  20. Vouchers--An Illusion of Choice.

    ERIC Educational Resources Information Center

    Ferguson, Janet M.

    2002-01-01

    Vouchers have been touted as a means to give parents more choice in their child's education, with the rationale that this choice will improve their child's chances of succeeding in school. Studies have produced mixed and inconclusive results. Critics argue that only the more motivated and higher income families will use the vouchers, thus…

  1. Voices on Choice: The Education Reform Debate.

    ERIC Educational Resources Information Center

    Billingsley, K. L., Ed.

    This collection presents a sampling of opinions of both proponents and opponents in the school choice debate from a variety of professional perspectives, including academics, bureaucrats, politicians, union leaders, economists, lawyers, parents, and activists. The following essays are included: (1) "School Choice Promotes Educational Excellence in…

  2. School Choice for Transnational Parents in Tokyo

    ERIC Educational Resources Information Center

    Velliaris, Donna M.; Willis, Craig R.

    2013-01-01

    School choice is centred on parents deciding where and how their children will be educated, and this issue is similar--to varying degrees--for parents all around the world. Parental school choice is the authority that parents exercise in making decisions about where their children will attend school, and choosing a particular educational pathway…

  3. Responsibility and School Choice in Education

    ERIC Educational Resources Information Center

    Colburn, Ben

    2012-01-01

    Consider the following argument for school choice, based on an appeal to the virtues of the market: allowing parents some measure of choice over their particular children's education ultimately serves the interests of all children, because creating a market mechanism in state education will produce improvements through the same pressures that lead…

  4. Household Mobility, School Choices, and School Outcomes.

    ERIC Educational Resources Information Center

    Bayer, Patrick J.

    This paper summarizes work from a dissertation, the main contribution of which was to develop and estimate a new empirical framework for analyzing the equilibrium outcomes of families' choices for choosing a particular residence. The principal component of the framework is a random-coefficients discrete-choice model of the residential location…

  5. Career Choice and Development. Third Edition.

    ERIC Educational Resources Information Center

    Brown, Duane; And Others

    This book contains 12 papers examining established and newly emerging theories of career choice and development. Following prefaces to the third, second, and first editions by Duane Brown and Linda Brooks, the following papers are included: "Introduction to Theories of Career Development and Choice: Origins, Evolution, and Current Efforts" (Duane…

  6. School Choice and the Achievement Gap

    ERIC Educational Resources Information Center

    Jeynes, William H.

    2014-01-01

    The possibility is examined that school choice programs could be a means to reducing the achievement gap. Data based on meta-analytic research and the examination of nationwide data sets suggest that school choice programs that include private schools could reduce the achievement gap by 25%. The propounding of this possibility is based on research…

  7. Evaluation of the Randomized Multiple Choice Format.

    ERIC Educational Resources Information Center

    Harke, Douglas James

    Each physics problem used in evaluating the effectiveness of Randomized Multiple Choice (RMC) tests was stated in the conventional manner and was followed by several multiple choice items corresponding to the steps in a written solution but presented in random order. Students were instructed to prepare a written answer and to use it to answer the…

  8. "Score Choice": A Tempest in a Teapot?

    ERIC Educational Resources Information Center

    Hoover, Eric

    2009-01-01

    A new option that allows students to choose which of their test scores to send to colleges has generated renewed criticism of the College Board. College Board officials tout the option, called Score Choice, as a way to ease test taker anxiety. Some prominent admissions officials have publicly described Score Choice as a sales tactic that will…

  9. Leadership Practices and School Choice. Research Brief

    ERIC Educational Resources Information Center

    Cravens, Xiu; Goldring, Ellen; Penaloza, Roberto V.

    2011-01-01

    As part of a larger study on school choice, researchers at the National Center on School Choice examined variation in leadership practices across school types, relying on a convenience matched sample of schools that included charter, magnet, private, and traditional public schools. A total of 284 schools agreed to participate in the study--116…

  10. A Chronology of Parental Choice in Education.

    ERIC Educational Resources Information Center

    McDonald, Sister Dale

    2001-01-01

    Traces the history of parental rights in education since the landmark case Pierce vs. the Society of Sisters (1925), when the existence of private schools was validated. States that initiatives promoting parental choice include : (1) tax relief/credits; (2) vouchers or scholarships; (3) public school choice; and (4) home schooling. Provides a…

  11. Race, Social Background, and School Choice Options

    ERIC Educational Resources Information Center

    Goyette, Kimberly A.

    2008-01-01

    This research contributes to discussions about social inequality in school choices in two ways. First, educational choices include the multitude of options families may consider, including choosing a home in a particular area and home-schooling. Decision-making is considered not at a single point in time, but over children's educational careers.…

  12. Lexical Choice: Towards Writing Problematic Word Lists.

    ERIC Educational Resources Information Center

    Zughoul, Muhammad Raji

    1991-01-01

    Quantitative and qualitative analysis of lexical choice errors made by native Arabic-speaking learners of English in written compositions indicated that first-language interference is a major variable in lexical choice. Results lend support to the development of problematic word lists to help learners adopt practical strategies for improving…

  13. Can "Word Choices" Compromise a Woman's Career?

    ERIC Educational Resources Information Center

    Mendoza, Sylvia

    2011-01-01

    A letter of recommendation can catapult a woman into the next phase of the interview process for a particular job--or land her in the slush pile. Word choice in describing this female candidate can make or break her career. Letters of recommendation--especially when a reference's word choice paints a negative, less than stellar picture of the…

  14. College Bound? Make the Right Choices

    ERIC Educational Resources Information Center

    Robinson, Jenna Ashley

    2009-01-01

    "College Bound? Make the Right Choices" is the Pope Center's latest tool for improving colleges and universities "from the bottom up" through better choices. Its purpose is to help high school students and their parents become smarter purchasers of higher education. This booklet by Jenna Ashley Robinson helps young people think through what they…

  15. Parental Choice in East Harlem Schools.

    ERIC Educational Resources Information Center

    Fliegel, Sy

    Poor students and parents in the East Harlem schools of New York City's Community District 4 should have the same opportunity to obtain the benefits of school choice available to the wealthy, who can afford private and parochial schools. Parental choice can provide the catalyst for educational reform by introducing a market mechanism to the public…

  16. Factors Influencing Teaching Choice in Turkey

    ERIC Educational Resources Information Center

    Kilinc, Ahmet; Watt, Helen M. G.; Richardson, Paul W.

    2012-01-01

    Why choose to become a teacher in Turkey? The authors examined motivations and perceptions among preservice teachers (N = 1577) encompassing early childhood, primary and secondary education. The Factors Influencing Teaching Choice (FIT-Choice) instrument was translated into Turkish and its construct validity and reliability assessed. Altruistic…

  17. Multiple-Choice and Alternate-Choice Questions: Description and Analysis.

    ERIC Educational Resources Information Center

    Dowd, Steven B.

    An alternative to multiple-choice (MC) testing is suggested as it pertains to the field of radiologic technology education. General principles for writing MC questions are given and contrasted with a new type of MC question, the alternate-choice (AC) question, in which the answer choices are embedded in the question in a short form that resembles…

  18. Increasing Choice-Making and Choice Awareness for Students with Intellectual Disability

    ERIC Educational Resources Information Center

    Sparks, Shannon Lynn

    2013-01-01

    A number of studies have suggested that when children with disabilities are presented with choice-making opportunities, they can make choices (Bambara, 2004; Carlson, Luiselli, Slyman, & Markowski, 2008; Dibley & Lim, 1999; Manhertz, 2006). Teaching choice-making to students with intellectual disability is an important skill. Students with…

  19. Hobson's Choice: Illusory Intervention Choice for Culturally and Linguistically Diverse Learners with Problem Behaviors

    ERIC Educational Resources Information Center

    Obiakor, Festus E.

    2012-01-01

    Hobson's choice is a "no-choice" choice that gives general and special educators the traditional impetus to do what they want in classrooms. While there is some "goodness" in having this power and audacity to control whatever happens in classrooms, it does not allow for creativity, flexibility, adaptability, modification, especially in behavior…

  20. Agency and Choice in Education: Does School Choice Enhance the Work Effort of Teachers?

    ERIC Educational Resources Information Center

    Rapp, Geoffrey C.

    2000-01-01

    Investigates effects of school-choice laws on U.S. teachers' work incentives, using 1993-94 Schools and Staffing Survey data. Examines whether school system competitiveness works to solve the principal-agent problem in education. Results are mixed, but suggest that one type of choice policy--intradistrict choice--enhances teacher motivation.…

  1. Choice Making Part I: How Children with Severe Disabilities Make Choices of Preference and Knowledge

    ERIC Educational Resources Information Center

    Van Tubbergen, Marie; Omichinski, Donna; Warschausky, Seth

    2007-01-01

    Communication can be difficult for children with conditions such as cerebral palsy because of speech and physical impairments. For this group of children, choice-making is often limited to choices of personal preferences; however, preferences do not reveal intellectual abilities. Therefore, choice-making should be presented to these children in…

  2. Hierarchical competitions subserving multi-attribute choice.

    PubMed

    Hunt, Laurence T; Dolan, Raymond J; Behrens, Timothy E J

    2014-11-01

    Valuation is a key tenet of decision neuroscience, where it is generally assumed that different attributes of competing options are assimilated into unitary values. Such values are central to current neural models of choice. By contrast, psychological studies emphasize complex interactions between choice and valuation. Principles of neuronal selection also suggest that competitive inhibition may occur in early valuation stages, before option selection. We found that behavior in multi-attribute choice is best explained by a model involving competition at multiple levels of representation. This hierarchical model also explains neural signals in human brain regions previously linked to valuation, including striatum, parietal and prefrontal cortex, where activity represents within-attribute competition, competition between attributes and option selection. This multi-layered inhibition framework challenges the assumption that option values are computed before choice. Instead, our results suggest a canonical competition mechanism throughout all stages of a processing hierarchy, not simply at a final choice stage. PMID:25306549

  3. Prenatal screening, reproductive choice, and public health.

    PubMed

    Wilkinson, Stephen

    2015-01-01

    One widely held view of prenatal screening (PNS) is that its foremost aim is, or should be, to enable reproductive choice; this is the Pure Choice view. The article critiques this position by comparing it with an alternative: Public Health Pluralism. It is argued that there are good reasons to prefer the latter, including the following. (1) Public Health Pluralism does not, as is often supposed, render PNS more vulnerable to eugenics-objections. (2) The Pure Choice view, if followed through to its logical conclusions, may have unpalatable implications, such as extending choice well beyond health screening. (3) Any sensible version of Public Health Pluralism will be capable of taking on board the moral seriousness of abortion and will advocate, where practicable, alternative means of reducing the prevalence of disease and disability. (4) Public Health Pluralism is at least as well-equipped as the Pure Choice model to deal with autonomy and consent issues. PMID:25521971

  4. Predicting free choices for abstract intentions.

    PubMed

    Soon, Chun Siong; He, Anna Hanxi; Bode, Stefan; Haynes, John-Dylan

    2013-04-01

    Unconscious neural activity has been repeatedly shown to precede and potentially even influence subsequent free decisions. However, to date, such findings have been mostly restricted to simple motor choices, and despite considerable debate, there is no evidence that the outcome of more complex free decisions can be predicted from prior brain signals. Here, we show that the outcome of a free decision to either add or subtract numbers can already be decoded from neural activity in medial prefrontal and parietal cortex 4 s before the participant reports they are consciously making their choice. These choice-predictive signals co-occurred with the so-called default mode brain activity pattern that was still dominant at the time when the choice-predictive signals occurred. Our results suggest that unconscious preparation of free choices is not restricted to motor preparation. Instead, decisions at multiple scales of abstraction evolve from the dynamics of preceding brain activity. PMID:23509300

  5. Prenatal Screening, Reproductive Choice, and Public Health

    PubMed Central

    Wilkinson, Stephen

    2015-01-01

    One widely held view of prenatal screening (PNS) is that its foremost aim is, or should be, to enable reproductive choice; this is the Pure Choice view. The article critiques this position by comparing it with an alternative: Public Health Pluralism. It is argued that there are good reasons to prefer the latter, including the following. (1) Public Health Pluralism does not, as is often supposed, render PNS more vulnerable to eugenics-objections. (2) The Pure Choice view, if followed through to its logical conclusions, may have unpalatable implications, such as extending choice well beyond health screening. (3) Any sensible version of Public Health Pluralism will be capable of taking on board the moral seriousness of abortion and will advocate, where practicable, alternative means of reducing the prevalence of disease and disability. (4) Public Health Pluralism is at least as well-equipped as the Pure Choice model to deal with autonomy and consent issues. PMID:25521971

  6. Differential neurobiological effects of expert advice on risky choice in adolescents and adults

    PubMed Central

    Moore, Sara; Monica Capra, C.

    2012-01-01

    We investigated behavioral and neurobiological mechanisms by which risk-averse advice, provided by an expert, affected risky decisions across three developmental groups [early adolescents (12–14 years), late adolescents (15–17 years), adults (18+ years)]. Using cumulative prospect theory, we modeled choice behavior during a risky-choice task. Results indicate that advice had a significantly greater impact on risky choice in both adolescent groups than in adults. Using functional magnetic resonance imaging, we investigated the neural correlates of this behavioral effect. Developmental effects on correlations between brain activity and valuation parameters were obtained in regions that can be classified into (i) cognitive control regions, such as dorsolateral prefrontal cortex (DLPFC) and ventrolateral PFC; (ii) social cognition regions, such as posterior temporoparietal junction; and (iii) reward-related regions, such as ventromedial PFC (vmPFC) and ventral striatum. Within these regions, differential effects of advice on neural correlates of valuation were observed across development. Specifically, advice increased the correlation strength between brain activity and parameters reflective of safe choice options in adolescent DLPFC and decreased correlation strength between activity and parameters reflective of risky choice options in adult vmPFC. Taken together, results indicate that, across development, distinct brain systems involved in cognitive control and valuation mediate the risk-reducing effect of advice during decision making under risk via specific enhancements and reductions of the correlation strength between brain activity and valuation parameters. PMID:22563008

  7. Young Australian women explain their contraceptive choices.

    PubMed

    Wigginton, Britta; Moran, Claire; Harris, Melissa L; Loxton, Deborah; Lucke, Jayne

    2016-07-01

    New developments in female contraceptives allow women increased options for preventing pregnancy, while men's options for reversible contraception have not advanced beyond the condom. There has been little discursive exploration of how neoliberal and postfeminist discourses shape women's accounts of choosing whether or not to use contraception. Our thematic discourse analysis of 760 free-text responses to a question about contraceptive choice considers the social and political climate that promotes the self-governed woman who freely chooses contraception. We examine the ways in which women formulated and defended their accounts of choice, focusing on the theme of free contraceptive choice that constructed women's choices as unconstrained by material, social and political forces. We identify two discursive strategies that underpinned this theme: a woman's body, a woman's choice and planning parenthood, and explore the ways in which choice was understood as a gendered entitlement and how contraceptive choices were shaped (and constrained) by women's plans for parenthood. We discuss the implications of these discursive strategies, and neoliberal and postfeminist discourses, in terms of the disallowance of any contextual, social and structural factors, including the absence of men in the 'contraceptive economy'. PMID:26670866

  8. Resolving the paradox of suboptimal choice.

    PubMed

    Zentall, Thomas R

    2016-01-01

    When humans engage in commercial (totally probabilistic) gambling they are making suboptimal choices because the return is generally less than the investment. This review (a) examines the literature on pigeon suboptimal choice, (b) describes the conditions under which it occurs, (c) identifies the mechanisms that appear to be responsible for the effect, and (d) suggests that similar processes may be able to account for analogous suboptimal choice when humans engage in commercial gambling. Pigeons show suboptimal choice when they choose between 1 alternative that 20% of the time provides them with a signal that they will always get fed or 80% of the time with a signal that they will not get fed (overall 20% reinforcement) and a second alternative that 100% of the time provides them with a signal that they will get fed 50% of the time (overall 50% reinforcement). The pigeons' strong preference for the suboptimal choice was investigated in a series of experiments that found the preference for the suboptimal alternative was determined by the value of the signal that predicted reinforcement, rather its frequency and that the frequency of the signal that predicted nonreinforcement had little effect on the suboptimal choice. Paradoxically, this account makes the prediction that pigeons will be indifferent between an alternative that 50% of the time provides a fully predictive stimulus for reinforcement and an alternative that 100% of the time provides a fully predictive stimulus for reinforcement. The similarities and differences of this suboptimal choice task to human gambling are discussed. PMID:26640967

  9. A fair range of choice: justifying maximum patient choice in the British National Health Service.

    PubMed

    Wilmot, Stephen

    2007-06-01

    In this paper I put forward an ethical argument for the provision of extensive patient choice by the British National Health Service. I base this argument on traditional liberal rights to freedom of choice, on a welfare right to health care, and on a view of health as values-based. I argue that choice, to be ethically sustainable on this basis, must be values-based and rational. I also consider whether the British taxpayer may be persuadable with regard to the moral acceptability of patient choice, making use of Rawls' theory of political liberalism in this context. I identify issues that present problems in terms of public acceptance of choice, and also identify a boundary issue with regard to public health choices as against individual choices. PMID:17628925

  10. Mitigating or exacerbating effects of maternal-fetal programming of female mice through the food choice environment.

    PubMed

    Brenseke, Bonnie; Bahamonde, Javiera; Talanian, Michael; Kornfeind, Ellie; Daly, Jacquiline; Cobb, Grayson; Zhang, Jinhua; Prater, M Renee; Davis, George C; Good, Deborah J

    2015-01-01

    Humans live, eat, and become overweight/obese in complex surroundings where there are many available food choices. Prenatal exposure to poor food choices predisposes offspring to increased negative health risks, including obesity. Many animal experiments have analyzed intergenerational body weight parameters in an environment without food choices, which may not be directly translatable to the human food environment. In this study, offspring from mothers with a defined high-fat diet (HFD) or low-fat diet (LFD) were arbitrarily assigned to either an exclusively LFD or HFD or to a diet where they have a choice between LFD and HFD (choice diet). Offspring displayed negative outcomes of increased body weight, body fat, serum leptin, and blood glucose levels when given the choice diet compared with offspring on the LFD. Conversely, improved energy expenditure was found for offspring given the choice diet compared with offspring from HFD dams given LFD. In addition, maternal diet-specific influences on offspring metabolic parameters were identified, especially in offspring from HFD dams, including positive outcomes of reduced leptin in LFD offspring, reduced corticosterone and cholesterol levels in HFD offspring, and increased exercise levels in choice offspring, as well as the negative outcome of increased calorie intake in LFD offspring from HFD dams. This defined model can now be used as the basis for future studies to characterize the cycle of inter- and intragenerational obesity and whether more realistic diet environments, especially those including choice, can mitigate phenotype. PMID:25386832

  11. Career choices among medical students in Bangladesh

    PubMed Central

    Ahmed, SM Moslehuddin; Majumdar, Md Anwarul Azim; Karim, Rezina; Rahman, Sayeeda; Rahman, Nuzhat

    2011-01-01

    Introduction Information regarding career choices of medical students is important to plan human resources for health, design need-based educational programs, and ensure equitable and quality health care services in a country. Aim The aim of the study is to identify career choices, nature of career, intended practice locations, and reasons for career choices of Bangladesh medical students. Method First-, third-, and fifth-year students of Bangladesh Medical College and Uttara Adhunik Medical College completed a self-report questionnaire on career choices, nature of career, intended practice locations, and reasons for career choices. The students were requested to choose three long-term choices from the given specialties. Results A total of 132 students responded (46 males and 86 females) and response rate was 75%. The popular choices (first choice) among males and females were medical specialty, surgical specialty, obstetrics and gynecology, and general practice. For first, second, and third choices altogether, male students chose surgical specialties and female students preferred medical specialties. The leading reasons for selecting a specialty were personal interest and wide job opportunity. More than 67% of respondents wanted to join private services and about 90% chose major cities as practice locations. About 43% of respondents expressed willingness to practice medicine in Bangladesh, whereas 51% of total respondents wanted to practice abroad. Discussion Majority of students intended to specialize in established clinical specialties and subsequently practice in major cities, and more than half wanted to immigrate to other countries. Basic medical subjects and service-oriented (lifestyle-related) and preventive/social medical specialties were found to be less attractive. If this pattern continues, Bangladesh will suffer a chronic shortage of health personnel in certain specialties and in rural areas. Conclusions Reorientation of health care and medical

  12. The costs of choice in sexual selection.

    PubMed

    Pomiankowski, A

    1987-09-21

    In Fisher's model of sexual selection female mating preferences are not subject to direct selection but evolve purely because they are genetically correlated with the favoured male trait. But when female choice is costly relative to random mating, for example in energy, time or predation risks, the evolution of female mating preference is subject also to direct selection. With costly female choice the set or line of equilibria found in models of Fisher's process no longer exists. On the line the male trait is under zero net selection, and there is no advantage for a female choosing a male with a more exaggerated character. Therefore any cost to choice causes choosiness to decline. In turn this lowers the strength of sexual selection and the male trait declines as well. So when Fisher's process is the sole force of sexual selection and female choice is costly, only transitory increases in female choice and the preferred male trait are possible. It has often been claimed that exaggerated male characters act as markers or revealers of the genetic quality of potential mates. If females choose their mates using traits that correlate with heritable viability differences then stable exaggeration of both female choice and the preferred male character is possible, even when female choice is costly. The offspring of choosy females have not only a Fisherian reproductive advantage but also greater viability. This suggests that in species with exaggerated male ornamentation, in which female choice is costly, it is likely that female mate choice will be for traits that correlate with male genetic quality. PMID:3431135

  13. Propulsion System Choices and Their Implications

    NASA Technical Reports Server (NTRS)

    Joyner, Claude R., II; Levack, Daniel J. H.; Rhodes, Russell, E.; Robinson, John W.

    2010-01-01

    In defining a space vehicle architecture, the propulsion system and related subsystem choices will have a major influence on achieving the goals and objectives desired. There are many alternatives and the choices made must produce a system that meets the performance requirements, but at the same time also provide the greatest opportunity of reaching all of the required objectives. Recognizing the above, the SPST Functional Requirements subteam has drawn on the knowledge, expertise, and experience of its members, to develop insight that wiIJ effectively aid the architectural concept developer in making the appropriate choices consistent with the architecture goals. This data not only identifies many selected choices, but also, more importantly, presents the collective assessment of this subteam on the "pros" and the "cons" of these choices. The propulsion system choices with their pros and cons are presented in five major groups. A. System Integration Approach. Focused on the requirement for safety, reliability, dependability, maintainability, and low cost. B. Non-Chemical Propulsion. Focused on choice of propulsion type. C. Chemical Propulsion. Focused on propellant choice implications. D. Functional Integration. Focused on the degree of integration of the many propulsive and closely associated functions, and on the choice of the engine combustion power cycle. E. Thermal Management. Focused on propellant tank insulation and integration. Each of these groups is further broken down into subgroups, and at that level the consensus pros and cons are presented. The intended use of this paper is to provide a resource of focused material for architectural concept developers to use in designing new advanced systems including college design classes. It is also a possible source of input material for developing a model for designing and analyzing advanced concepts to help identify focused technology needs and their priorities.

  14. Choice of Variables and Preconditioning for Time Dependent Problems

    NASA Technical Reports Server (NTRS)

    Turkel, Eli; Vatsa, Verr N.

    2003-01-01

    We consider the use of low speed preconditioning for time dependent problems. These are solved using a dual time step approach. We consider the effect of this dual time step on the parameter of the low speed preconditioning. In addition, we compare the use of two sets of variables, conservation and primitive variables, to solve the system. We show the effect of these choices on both the convergence to a steady state and the accuracy of the numerical solutions for low Mach number steady state and time dependent flows.

  15. School Choice, School Quality and Postsecondary Attainment

    PubMed Central

    Deming, David J.; Hastings, Justine S.; Kane, Thomas J.; Staiger, Douglas O.

    2015-01-01

    We study the impact of a public school choice lottery in Charlotte-Mecklenburg schools on college enrollment and degree completion. We find a significant overall increase in college attainment among lottery winners who attend their first choice school. Using rich administrative data on peers, teachers, course offerings and other inputs, we show that the impacts of choice are strongly predicted by gains on several measures of school quality. Gains in attainment are concentrated among girls. Girls respond to attending a better school with higher grades and increases in college-preparatory course-taking, while boys do not. PMID:27244675

  16. Editor's Choice Offered as a Service

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    2010-06-01

    Editor's Choice is now being offered as a service rather than on a subscription basis. As in the past, articles will be selected by collection editors with assistance from advisory panels. The selected articles will be listed on the AGU Web site (http://www.agu.org/pubs/journals/virtual/editors_choice/); these lists will be accessible to anyone. Those who are interested in reading the articles can access them through a personal or institutional subscription or can purchase them either individually or as part of a MultiChoice packet.

  17. Pro-choice: a new militancy.

    PubMed

    Davis, S E

    1989-01-01

    Davis, a pro-choice advocate, describes the reactions of the abortion rights movement to the U.S. Supreme Court's opinion in the 1989 Webster v. Reproductive Health Services case. Viewing the decision that allows individual states to set some restrictions on abortion as a threat to women's reproductive rights, pro-choice advocates have responded "with a new sense of defiance and commitment." Davis describes the demonstrations, sit-ins, and coalitions that give evidence of the new activism of the pro-choice movement. PMID:2606658

  18. Estimation of Dynamic Discrete Choice Models by Maximum Likelihood and the Simulated Method of Moments

    PubMed Central

    Eisenhauer, Philipp; Heckman, James J.; Mosso, Stefano

    2015-01-01

    We compare the performance of maximum likelihood (ML) and simulated method of moments (SMM) estimation for dynamic discrete choice models. We construct and estimate a simplified dynamic structural model of education that captures some basic features of educational choices in the United States in the 1980s and early 1990s. We use estimates from our model to simulate a synthetic dataset and assess the ability of ML and SMM to recover the model parameters on this sample. We investigate the performance of alternative tuning parameters for SMM. PMID:26494926

  19. Stochastic Matching and the Voluntary Nature of Choice

    PubMed Central

    Neuringer, Allen; Jensen, Greg; Piff, Paul

    2007-01-01

    Attempts to characterize voluntary behavior have been ongoing for thousands of years. We provide experimental evidence that judgments of volition are based upon distributions of responses in relation to obtained rewards. Participants watched as responses, said to be made by “actors,” appeared on a computer screen. The participant's task was to estimate how well each actor represented the voluntary choices emitted by a real person. In actuality, all actors' responses were generated by algorithms based on Baum's (1979) generalized matching function. We systematically varied the exponent values (sensitivity parameter) of these algorithms: some actors matched response proportions to received reinforcer proportions, others overmatched (predominantly chose the highest-valued alternative), and yet others undermatched (chose relatively equally among the alternatives). In each of five experiments, we found that the matching actor's responses were judged most closely to approximate voluntary choice. We found also that judgments of high volition depended upon stochastic (or probabilistic) generation. Thus, stochastic responses that match reinforcer proportions best represent voluntary human choice. PMID:17725049

  20. Nuclear Energy - A Fateful Choice for France

    ERIC Educational Resources Information Center

    Bauer, Etienne; And Others

    1976-01-01

    In France the public is only moderately interested in technological problems, and so the question of energy choices has not seeped deeply into the political consciousness. The situation could change as the country strengthens its nuclear commitment. (BT)

  1. Irrational choice and the value of information

    PubMed Central

    Vasconcelos, Marco; Monteiro, Tiago; Kacelnik, Alex

    2015-01-01

    Irrational decision making in humans and other species challenges the use of optimality in behavioural biology. Here we show that such observations are in fact powerful tools to understand the adaptive significance of behavioural mechanisms. We presented starlings choices between probabilistic alternatives, receiving or not information about forthcoming, delayed outcomes after their choices. Subjects could not use this information to alter the outcomes. Paradoxically, outcome information induced loss-causing preference for the lower probability option. The effect depended on time under uncertainty: information given just after each choice caused strong preference for lower probability, but information just before the outcome did not. A foraging analysis shows that these preferences would maximize gains if post-choice information were usable, as when predators abandon a chase when sure of the prey escaping. Our study illustrates how experimentally induced irrational behaviour supports rather than weakens the evolutionary optimality approach to animal behaviour. PMID:26350951

  2. Refusing The Choice: Balancing Life and Work

    NASA Astrophysics Data System (ADS)

    Brooks, J.

    2012-12-01

    The Choice The intellect of man is forced to choose perfection of the life, or of the work, And if it take the second must refuse A heavenly mansion, raging in the dark. When all that story's finished, what's the news? In luck or out the toil has left its mark: That old perplexity an empty purse, Or the day's vanity, the night's remorse. William Butler Yeats William Yeats put forward The Choice that I feel too many scientists feel they must make. Too often, many choose to leave science. How do we refuse this choice and find balance between life and our careers? While I don't know the answer, I will share choices that have lead to not perfection but satisfaction in science careers and lives. The role of mentors, supportive spouses, the luck of the job, and flexibility in research directions have all contributed to being able to refuse to choose.

  3. Strategy application, observability, and the choice combinator.

    SciTech Connect

    Winter, Victor Lono

    2004-03-01

    In many strategic systems, the choice combinator provides a powerful mechanism for controlling the application of rules and strategies to terms. The ability of the choice combinator to exercise control over rewriting is based on the premise that the success and failure of strategy application can be observed. In this paper we present a higher-order strategic framework with the ability to dynamically construct strategies containing the choice combinator. To this framework, a combinator called hide is introduced that prevents the successful application of a strategy from being observed by the choice combinator. We then explore the impact of this new combinator on a real-world problem involving a restricted implementation of the Java Virtual Machine.

  4. Time scarcity and food choices: an overview.

    PubMed

    Jabs, Jennifer; Devine, Carol M

    2006-09-01

    Time scarcity, the feeling of not having enough time, has been implicated in changes in food consumption patterns such as a decrease in food preparation at home, an increase in the consumption of fast foods, a decrease in family meals, and an increase in the consumption of convenience or ready-prepared foods. These food choices are associated with less healthful diets and may contribute to obesity and chronic health problems such as cardiovascular disease, diabetes, and cancer. In spite of the potential importance for health, there has been little study of how time scarcity influences people's food choices. This paper presents an overview of time issues related to food choices and discuss applications of time research for nutrition and health researchers, policy makers, and practitioners interested in food choice. PMID:16698116

  5. Facilitating women's choice in maternity care.

    PubMed

    Nieuwenhuijze, Marianne; Low, Lisa Kane

    2013-01-01

    Maternity careproviders often have strong views concerning a woman's choice of where to give birth.These views may be based on the ethical principle of autonomy, or on the principle of beneficence. The authors propose that an approach utilizing shared decision making allows careproviders and women to move beyond disagreements regarding which evidence on risk should "counts' instead adopting a process of increased knowledge and support for women and their partner while they make choices regarding place of birth. PMID:24282854

  6. Improved discriminability of spatiotemporal neural patterns in rat motor cortical areas as directional choice learning progresses

    PubMed Central

    Mao, Hongwei; Yuan, Yuan; Si, Jennie

    2015-01-01

    Animals learn to choose a proper action among alternatives to improve their odds of success in food foraging and other activities critical for survival. Through trial-and-error, they learn correct associations between their choices and external stimuli. While a neural network that underlies such learning process has been identified at a high level, it is still unclear how individual neurons and a neural ensemble adapt as learning progresses. In this study, we monitored the activity of single units in the rat medial and lateral agranular (AGm and AGl, respectively) areas as rats learned to make a left or right side lever press in response to a left or right side light cue. We noticed that rat movement parameters during the performance of the directional choice task quickly became stereotyped during the first 2–3 days or sessions. But learning the directional choice problem took weeks to occur. Accompanying rats' behavioral performance adaptation, we observed neural modulation by directional choice in recorded single units. Our analysis shows that ensemble mean firing rates in the cue-on period did not change significantly as learning progressed, and the ensemble mean rate difference between left and right side choices did not show a clear trend of change either. However, the spatiotemporal firing patterns of the neural ensemble exhibited improved discriminability between the two directional choices through learning. These results suggest a spatiotemporal neural coding scheme in a motor cortical neural ensemble that may be responsible for and contributing to learning the directional choice task. PMID:25798093

  7. Multi-choice stochastic bi-level programming problem in cooperative nature via fuzzy programming approach

    NASA Astrophysics Data System (ADS)

    Maiti, Sumit Kumar; Roy, Sankar Kumar

    2016-05-01

    In this paper, a Multi-Choice Stochastic Bi-Level Programming Problem (MCSBLPP) is considered where all the parameters of constraints are followed by normal distribution. The cost coefficients of the objective functions are multi-choice types. At first, all the probabilistic constraints are transformed into deterministic constraints using stochastic programming approach. Further, a general transformation technique with the help of binary variables is used to transform the multi-choice type cost coefficients of the objective functions of Decision Makers(DMs). Then the transformed problem is considered as a deterministic multi-choice bi-level programming problem. Finally, a numerical example is presented to illustrate the usefulness of the paper.

  8. Choice and timing in pigeons under differing levels of food deprivation.

    PubMed

    Fox, Adam E; Kyonka, Elizabeth G E

    2014-07-01

    State-dependent valuation learning (SDVL) is a preference for stimuli associated with relative food deprivation over stimuli associated with relative satiety. Pigeons were exposed to experimental conditions designed to investigate SDVL and to test the hypothesis that obtained relative immediacy during training predicts choice during test probes. Energy states were manipulated using a procedure that has previously revealed SDVL in starlings and pigeons. In Experiment 1, pigeons preferred the stimulus associated with deprivation in the first choice probe session, but were indifferent in the second. Changes in choice were consistent with changes in obtained relative immediacy. In Experiment 2, training parameters were altered and SDVL did not occur. Obtained relative immediacy again predicted choice. Results of both experiments provide evidence that obtained relative immediacy may be an important contributing factor to the SDVL phenomenon. PMID:24811449

  9. Enhancing Consumer Choice: Are We Making Appropriate Recommendations?

    ERIC Educational Resources Information Center

    Lee, Jinkook; Geistfeld, Loren V.

    1998-01-01

    This study used conjoint analysis to identify consumer choice models. Results suggest a need to base choice-making aids on ideal choice models if the aid is to lead consumers to decisions consistent with true preferences. (Author/JOW)

  10. Partner Choice in Raven (Corvus corax) Cooperation

    PubMed Central

    Asakawa-Haas, Kenji; Schiestl, Martina; Bugnyar, Thomas; Massen, Jorg J. M.

    2016-01-01

    Although social animals frequently make decisions about when or with whom to cooperate, little is known about the underlying mechanisms of partner choice. Most previous studies compared different dyads’ performances, though did not allow an actual choice among partners. We tested eleven ravens, Corvus corax, in triads, giving them first the choice to cooperate with either a highly familiar or a rather unfamiliar partner and, second, with either a friend or a non-friend using a cooperative string-pulling task. In either test, the ravens had a second choice and could cooperate with the other partner, given that this one had not pulled the string in the meantime. We show that during the experiments, these partner ravens indeed learn to wait and inhibit pulling, respectively. Moreover, the results of these two experiments show that ravens’ preferences for a specific cooperation partner are not based on familiarity. In contrast, the ravens did show a preference based on relationship quality, as they did choose to cooperate significantly more with friends than with non-friends and they were also more proficient when cooperating with a friend. In order to further identify the proximate mechanism of this preference, we designed an open-choice experiment for the whole group where all birds were free to cooperate on two separate apparatuses. This set-up allowed us to distinguish between preferences for close proximity and preferences to cooperate. The results revealed that friends preferred staying close to each other, but did not necessarily cooperate with one another, suggesting that tolerance of proximity and not relationship quality as a whole may be the driving force behind partner choice in raven cooperation. Consequently, we stress the importance of experiments that allow such titrations and, suggest that these results have important implications for the interpretations of cooperation studies that did not include open partner choice. PMID:27286247

  11. Search, Memory, and Choice Error: An Experiment

    PubMed Central

    Sanjurjo, Adam

    2015-01-01

    Multiple attribute search is a central feature of economic life: we consider much more than price when purchasing a home, and more than wage when choosing a job. An experiment is conducted in order to explore the effects of cognitive limitations on choice in these rich settings, in accordance with the predictions of a new model of search memory load. In each task, subjects are made to search the same information in one of two orders, which differ in predicted memory load. Despite standard models of choice treating such variations in order of acquisition as irrelevant, lower predicted memory load search orders are found to lead to substantially fewer choice errors. An implication of the result for search behavior, more generally, is that in order to reduce memory load (thus choice error) a limited memory searcher ought to deviate from the search path of an unlimited memory searcher in predictable ways-a mechanism that can explain the systematic deviations from optimal sequential search that have recently been discovered in peoples' behavior. Further, as cognitive load is induced endogenously (within the task), and found to affect choice behavior, this result contributes to the cognitive load literature (in which load is induced exogenously), as well as the cognitive ability literature (in which cognitive ability is measured in a separate task). In addition, while the information overload literature has focused on the detrimental effects of the quantity of information on choice, this result suggests that, holding quantity constant, the order that information is observed in is an essential determinant of choice failure. PMID:26121356

  12. Search, Memory, and Choice Error: An Experiment.

    PubMed

    Sanjurjo, Adam

    2015-01-01

    Multiple attribute search is a central feature of economic life: we consider much more than price when purchasing a home, and more than wage when choosing a job. An experiment is conducted in order to explore the effects of cognitive limitations on choice in these rich settings, in accordance with the predictions of a new model of search memory load. In each task, subjects are made to search the same information in one of two orders, which differ in predicted memory load. Despite standard models of choice treating such variations in order of acquisition as irrelevant, lower predicted memory load search orders are found to lead to substantially fewer choice errors. An implication of the result for search behavior, more generally, is that in order to reduce memory load (thus choice error) a limited memory searcher ought to deviate from the search path of an unlimited memory searcher in predictable ways-a mechanism that can explain the systematic deviations from optimal sequential search that have recently been discovered in peoples' behavior. Further, as cognitive load is induced endogenously (within the task), and found to affect choice behavior, this result contributes to the cognitive load literature (in which load is induced exogenously), as well as the cognitive ability literature (in which cognitive ability is measured in a separate task). In addition, while the information overload literature has focused on the detrimental effects of the quantity of information on choice, this result suggests that, holding quantity constant, the order that information is observed in is an essential determinant of choice failure. PMID:26121356

  13. A priori and a posteriori dietary patterns at the age of 1 year and body composition at the age of 6 years: the Generation R Study.

    PubMed

    Voortman, Trudy; Leermakers, Elisabeth T M; Franco, Oscar H; Jaddoe, Vincent W V; Moll, Henriette A; Hofman, Albert; van den Hooven, Edith H; Kiefte-de Jong, Jessica C

    2016-08-01

    Dietary patterns have been linked to obesity in adults, however, not much is known about this association in early childhood. We examined associations of different types of dietary patterns in 1-year-old children with body composition at school age in 2026 children participating in a population-based cohort study. Dietary intake at the age of 1 year was assessed with a food-frequency questionnaire. At the children's age of 6 years we measured their body composition with dual-energy X-ray absorptiometry and we calculated body mass index, fat mass index (FMI), and fat-free mass index (FFMI). Three dietary pattern approaches were used: (1) An a priori-defined diet quality score; (2) dietary patterns based on variation in food intake, derived from principal-component-analysis (PCA); and (3) dietary patterns based on variations in FMI and FFMI, derived with reduced-rank-regression (RRR). Both the a priori-defined diet score and a 'Health-conscious' PCA-pattern were characterized by a high intake of fruit, vegetables, grains, and vegetable oils, and, after adjustment for confounders, children with higher adherence to these patterns had a higher FFMI at 6 years [0.19 SD (95 % CI 0.08;0.30) per SD increase in diet score], but had no different FMI. One of the two RRR-patterns was also positively associated with FFMI and was characterized by intake of whole grains, pasta and rice, and vegetable oils. Our results suggest that different a priori- and a posteriori-derived health-conscious dietary patterns in early childhood are associated with a higher fat-free mass, but not with fat mass, in later childhood. PMID:27384175

  14. Choice-Induced Preference Change in the Free-Choice Paradigm: A Critical Methodological Review

    PubMed Central

    Izuma, Keise; Murayama, Kou

    2013-01-01

    Choices not only reflect our preference, but they also affect our behavior. The phenomenon of choice-induced preference change has been of interest to cognitive dissonance researchers in social psychology, and more recently, it has attracted the attention of researchers in economics and neuroscience. Preference modulation after the mere act of making a choice has been repeatedly demonstrated over the last 50 years by an experimental paradigm called the “free-choice paradigm.” However, Chen and Risen (2010) pointed out a serious methodological flaw in this paradigm, arguing that evidence for choice-induced preference change is still insufficient. Despite the flaw, studies using the traditional free-choice paradigm continue to be published without addressing the criticism. Here, aiming to draw more attention to this issue, we briefly explain the methodological problem, and then describe simple simulation studies that illustrate how the free-choice paradigm produces a systematic pattern of preference change consistent with cognitive dissonance, even without any change in true preference. Our stimulation also shows how a different level of noise in each phase of the free-choice paradigm independently contributes to the magnitude of artificial preference change. Furthermore, we review ways of addressing the critique and provide a meta-analysis to show the effect size of choice-induced preference change after addressing the critique. Finally, we review and discuss, based on the results of the stimulation studies, how the criticism affects our interpretation of past findings generated from the free-choice paradigm. We conclude that the use of the conventional free-choice paradigm should be avoided in future research and the validity of past findings from studies using this paradigm should be empirically re-established. PMID:23404185

  15. Partner choice creates fairness in humans.

    PubMed

    Debove, Stéphane; André, Jean-Baptiste; Baumard, Nicolas

    2015-06-01

    Many studies demonstrate that partner choice has played an important role in the evolution of human cooperation, but little work has tested its impact on the evolution of human fairness. In experiments involving divisions of money, people become either over-generous or over-selfish when they are in competition to be chosen as cooperative partners. Hence, it is difficult to see how partner choice could result in the evolution of fair, equal divisions. Here, we show that this puzzle can be solved if we consider the outside options on which partner choice operates. We conduct a behavioural experiment, run agent-based simulations and analyse a game-theoretic model to understand how outside options affect partner choice and fairness. All support the conclusion that partner choice leads to fairness only when individuals have equal outside options. We discuss how this condition has been met in our evolutionary history, and the implications of these findings for our understanding of other aspects of fairness less specific than preferences for equal divisions of resources. PMID:25972467

  16. Quantum erasure with causally disconnected choice.

    PubMed

    Ma, Xiao-Song; Kofler, Johannes; Qarry, Angie; Tetik, Nuray; Scheidl, Thomas; Ursin, Rupert; Ramelow, Sven; Herbst, Thomas; Ratschbacher, Lothar; Fedrizzi, Alessandro; Jennewein, Thomas; Zeilinger, Anton

    2013-01-22

    The counterintuitive features of quantum physics challenge many common-sense assumptions. In an interferometric quantum eraser experiment, one can actively choose whether or not to erase which-path information (a particle feature) of one quantum system and thus observe its wave feature via interference or not by performing a suitable measurement on a distant quantum system entangled with it. In all experiments performed to date, this choice took place either in the past or, in some delayed-choice arrangements, in the future of the interference. Thus, in principle, physical communications between choice and interference were not excluded. Here, we report a quantum eraser experiment in which, by enforcing Einstein locality, no such communication is possible. This is achieved by independent active choices, which are space-like separated from the interference. Our setup employs hybrid path-polarization entangled photon pairs, which are distributed over an optical fiber link of 55 m in one experiment, or over a free-space link of 144 km in another. No naive realistic picture is compatible with our results because whether a quantum could be seen as showing particle- or wave-like behavior would depend on a causally disconnected choice. It is therefore suggestive to abandon such pictures altogether. PMID:23288900

  17. Parental role models, gender and educational choice.

    PubMed

    Dryler, H

    1998-09-01

    Parental role models are often put forward as an explanation for the choice of gender-atypical educational routes. This paper aims to test such explanations by examining the impact of family background variables like parental education and occupation, on choice of educational programme at upper secondary school. Using a sample of around 73,000 Swedish teenagers born between 1972 and 1976, girls' and boys' gender-atypical as well as gender-typical educational choices are analysed by means of logistic regression. Parents working or educated within a specific field increase the probability that a child will make a similar choice of educational programme at upper secondary school. This same-sector effect appeared to be somewhat stronger for fathers and sons, while no such same-sex influence was confirmed for girls. No evidence was found that, in addition to a same-sector effect, it matters whether parents' occupations represent gender-traditional or non-traditional models. Parents of the service classes or highly educated parents--expected to be the most gender egalitarian in attitudes and behaviours--have a positive influence upon children's choice of gender-atypical education. PMID:9867028

  18. Partner choice creates fairness in humans

    PubMed Central

    Debove, Stéphane; André, Jean-Baptiste; Baumard, Nicolas

    2015-01-01

    Many studies demonstrate that partner choice has played an important role in the evolution of human cooperation, but little work has tested its impact on the evolution of human fairness. In experiments involving divisions of money, people become either over-generous or over-selfish when they are in competition to be chosen as cooperative partners. Hence, it is difficult to see how partner choice could result in the evolution of fair, equal divisions. Here, we show that this puzzle can be solved if we consider the outside options on which partner choice operates. We conduct a behavioural experiment, run agent-based simulations and analyse a game-theoretic model to understand how outside options affect partner choice and fairness. All support the conclusion that partner choice leads to fairness only when individuals have equal outside options. We discuss how this condition has been met in our evolutionary history, and the implications of these findings for our understanding of other aspects of fairness less specific than preferences for equal divisions of resources. PMID:25972467

  19. A Response Model for Multiple Choice Items. Psychometric Technical Report No. 1.

    ERIC Educational Resources Information Center

    Thissen, David; Steinberg, Lynne

    An extension of the Bock-Samejima model for multiple choice items is introduced. The model provides for varying probabilities of the response alternative when the examinee guesses. A marginal maximum likelihood method is devised for estimating the item parameters, and likelihood ratio tests for comparing more and less constrained forms of the…

  20. The "Tyranny of Choice": Choice Overload as a Possible Instance of Effort Discounting

    ERIC Educational Resources Information Center

    Reed, Derek D.; Reed, Florence D. DiGennaro; Chok, James; Brozyna, Gary A.

    2011-01-01

    When making a choice, people like to have options, but an emerging literature on "choice overload" suggests that the provision of too many options results in adverse experiences, including a depletion of cognitive resources and postdecision feelings of regret. A strong implication is that individuals should shy away from situations involving too…

  1. Comparative Reliabilities and Validities of Multiple Choice and Complex Multiple Choice Nursing Education Tests.

    ERIC Educational Resources Information Center

    Dryden, Russell E.; Frisbie, David A.

    The purpose of this study was to compare certain characteristics of multiple-choice (MC) and complex multiple-choice (CMC) achievement tests designed to measure knowledge in medical-surgical nursing. Each of 268 junior and senior nursing students from four midwestern schools responded to one of four test forms. MC items were developed by…

  2. Preferences, Information, and Parental Choice Behavior in Public School Choice. NBER Working Paper No. 12995

    ERIC Educational Resources Information Center

    Hastings, Justine S.; Van Weelden, Richard; Weinstein, Jeffrey

    2007-01-01

    The incentives and outcomes generated by public school choice depend to a large degree on parents' choice behavior. There is growing empirical evidence that low-income parents place lower weights on academics when choosing schools, but there is little evidence as to why. We use a field experiment in the Charlotte-Mecklenburg Public School district…

  3. Choice and Opportunity: The Past and Future of Choice-Based Aid in Louisiana

    ERIC Educational Resources Information Center

    Carpenter, Dick M., II; Ross, John K.

    2008-01-01

    On February 29, 2008, Gov. Bobby Jindal presented the Louisiana Legislature with a proposed budget allocating $10 million for a school choice initiative that would enable parents in New Orleans to send their children to the school of their choice, including private schools, with state-funded scholarships. Leaders of the public school establishment…

  4. Similar Performance, but Different Choices: Social Class and Higher Education Choice in Greece

    ERIC Educational Resources Information Center

    Sianou-Kyrgiou, Eleni; Tsiplakides, Iakovos

    2011-01-01

    Higher education choice has been a central theme in sociological research in recent decades, especially following the policies for the widening of participation adopted in many countries. Research has shown a relationship between social class and higher education choice, and this is a reason why the expansion of higher education does not reduce…

  5. Transition Choices Program: Preparing To Participate in Life's Choices. Teaching Guide and Curriculum.

    ERIC Educational Resources Information Center

    Stowitschek, Joseph J.; And Others

    The Transition Choices Program (TCP) is designed to increase the ability of young persons with disabilities to participate more fully in the school-to-adult life process through systematic instruction in six skills: exploring choices and developing preferences; planning goals and following through; seeking assistance when needed; recognizing and…

  6. Will Choice Hurt? Compared to What? A School Choice Experiment in Estonia

    ERIC Educational Resources Information Center

    Põder, Kaire; Lauri, Triin

    2014-01-01

    This article presents the empirical analysis of the effects of a school choice policy in Estonia. The article shows that relying on markets and giving autonomy to the schools over student selection will produce admission tests, even at the elementary school level. This article's contribution is to show that a school choice policy experiment…

  7. Restricted Choices, Limited Options: Implementing Choice and Supplemental Educational Services in No Child Left Behind

    ERIC Educational Resources Information Center

    Fusarelli, Lance D.

    2007-01-01

    This article reviews implementation of the school choice and supplementary educational services provisions contained in the No Child Left Behind Act. School district progress, resistance, and obstacles to implementation are discussed and a number of practical remedies to improve implementation of school choice and supplemental educational services…

  8. Tool Match. Review Software for Basic CHOICE. CHOICE (Challenging Options in Career Education).

    ERIC Educational Resources Information Center

    Pitts, Ilse M.; And Others

    CHOICE Tool Match is an Apple computer concentration-type activity in which learners select two numbered windows in an attempt to match the tools displayed, reinforcing job and role information presented in the CHOICE Basic Job and Role activity folders and workbooks for migrant students. In place of written directions, the learner is provided…

  9. Choice Making Part II: Parental Choices and Decision-Making--Navigating Your Child's Cognitive Assessment

    ERIC Educational Resources Information Center

    Omichinski, Donna; Van Tubbergen, Marie; Warschausky, Seth

    2007-01-01

    Parenting a child with special needs can be perplexing and overwhelming journey which requires parents to make choices in unfamiliar territory. The manner in which parents make choices for their children establishes a model and sets a tone for what they expect their children to learn as well as what we expect of the people who serve their…

  10. Refocusing College Choice: Women's Reflections on Their Postsecondary Education Choices

    ERIC Educational Resources Information Center

    Bergerson, Amy A.; Heiselt, April K.; Aiken-Wisniewski, Sharon

    2013-01-01

    College choice is often tied to persistence and it emphasizes how family background affects both enrollment in higher education and persistence to degree. Despite extensive research related to both access to higher education and choice processes, there is still much to be learned about students' postsecondary decisions. This qualitative study…

  11. Final Report of Project CHOICE: A Center for Helping Organizations Improve Choice in Education.

    ERIC Educational Resources Information Center

    Chapman, Davis W.; And Others

    The purpose of the Center for Helping Organizations Improve Choice in Education (CHOICE) project, the scope of its activities, and evaluations of the effectiveness of those activities are described. One major project goal was to encourage and facilitate institutional efforts to provide more complete and accurate information to prospective…

  12. School Choice, Competition, and Academic Quality: Essays on the Milwaukee Parental Choice Program

    ERIC Educational Resources Information Center

    Mader, Nicholas Salomon

    2010-01-01

    The essays of this dissertation contribute to the understanding of how public schools respond to competition in educational markets. Evidence is drawn from the Milwaukee Parental Choice Program, the longest-running and largest-scale private school voucher program in the United States. A major justification school choice programs is that they…

  13. Determinants of Awareness, Consideration, and Choice Set Size in University Choice.

    ERIC Educational Resources Information Center

    Dawes, Philip L.; Brown, Jennifer

    2002-01-01

    Developed and tested a model of students' university "brand" choice using five individual-level variables (ethnic group, age, gender, number of parents going to university, and academic ability) and one situational variable (duration of search) to explain variation in the sizes of awareness, consideration, and choice decision sets. (EV)

  14. Efficient and Flexible Strategy Use on Multi-Digit Sums: A Choice/No-Choice Study

    ERIC Educational Resources Information Center

    Torbeyns, Joke; Verschaffel, Lieven

    2013-01-01

    This study analysed children's use of mental computation strategies and standard written algorithms in the domain of multi-digit addition and subtraction, using the choice/no-choice method. Twenty-one Flemish fourth-graders (M[subscript Age] =9y10m) solved problem-items that either stimulated the use of mental computation strategies or a standard…

  15. Serotonergic Genotypes, Neuroticism, and Financial Choices

    PubMed Central

    Kuhnen, Camelia M.; Samanez-Larkin, Gregory R.; Knutson, Brian

    2013-01-01

    Life financial outcomes carry a significant heritable component, but the mechanisms by which genes influence financial choices remain unclear. Focusing on a polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR), we found that individuals possessing the short allele of this gene invested less in equities, were less engaged in actively making investment decisions, and had fewer credit lines. Short allele carriers also showed higher levels of the personality trait neuroticism, despite not differing from others with respect to cognitive skills, education, or wealth. Mediation analysis suggested that the presence of the 5-HTTLPR short allele decreased real life measures of financial risk taking through its influence on neuroticism. These findings show that 5-HTTLPR short allele carriers avoid risky and complex financial choices due to negative emotional reactions, and have implications for understanding and managing individual differences in financial choice. PMID:23382929

  16. Wheeler thought experiment with delayed choice

    NASA Astrophysics Data System (ADS)

    Boyd, Jeffrey

    2012-02-01

    This is an alternative interpretation of Jacques, et. al. (2007), Wheeler's thought experiment with delayed choice. The researchers find that the choice of observables changes the previous behavior of the photon inside the interferometer. Stepping outside the QM box, we propose that elementary waves from the detectors travel backwards through the interferometer, and the photon is following such a ray in the reverse direction. Thus a change in observables changes the behavior of the photon for the simple reason that the observable is transmitting information to the photon and the photon is able to change its polarization mid-stream in response to a change in that information. According to this explanation there is no delayed choice. It is an illusion.

  17. A quantum delayed-choice experiment.

    PubMed

    Peruzzo, Alberto; Shadbolt, Peter; Brunner, Nicolas; Popescu, Sandu; O'Brien, Jeremy L

    2012-11-01

    Quantum systems exhibit particle- or wavelike behavior depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics. Its paradoxical nature is best captured in the delayed-choice thought experiment, in which a photon is forced to choose a behavior before the observer decides what to measure. Here, we report on a quantum delayed-choice experiment in which both particle and wave behaviors are investigated simultaneously. The genuinely quantum nature of the photon's behavior is certified via nonlocality, which here replaces the delayed choice of the observer in the original experiment. We observed strong nonlocal correlations, which show that the photon must simultaneously behave both as a particle and as a wave. PMID:23118183

  18. Does reflection lead to wise choices?

    PubMed Central

    Bortolotti, Lisa

    2011-01-01

    Does conscious reflection lead to good decision-making? Whereas engaging in reflection is traditionally thought to be the best way to make wise choices, recent psychological evidence undermines the role of reflection in lay and expert judgement. The literature suggests that thinking about reasons does not improve the choices people make, and that experts do not engage in reflection, but base their judgements on intuition, often shaped by extensive previous experience. Can we square the traditional accounts of wisdom with the results of these empirical studies? Should we even attempt to? I shall defend the view that philosophy and cognitive sciences genuinely interact in tackling questions such as whether reflection leads to making wise choices. PMID:22408385

  19. When good news leads to bad choices.

    PubMed

    McDevitt, Margaret A; Dunn, Roger M; Spetch, Marcia L; Ludvig, Elliot A

    2016-01-01

    Pigeons and other animals sometimes deviate from optimal choice behavior when given informative signals for delayed outcomes. For example, when pigeons are given a choice between an alternative that always leads to food after a delay and an alternative that leads to food only half of the time after a delay, preference changes dramatically depending on whether the stimuli during the delays are correlated with (signal) the outcomes or not. With signaled outcomes, pigeons show a much greater preference for the suboptimal alternative than with unsignaled outcomes. Key variables and research findings related to this phenomenon are reviewed, including the effects of durations of the choice and delay periods, probability of reinforcement, and gaps in the signal. We interpret the available evidence as reflecting a preference induced by signals for good news in a context of uncertainty. Other explanations are briefly summarized and compared. PMID:26781050

  20. Subject–Motion Correction in HARDI Acquisitions: Choices and Consequences

    PubMed Central

    Elhabian, Shireen; Gur, Yaniv; Vachet, Clement; Piven, Joseph; Styner, Martin; Leppert, Ilana R.; Pike, G. Bruce; Gerig, Guido

    2014-01-01

    Diffusion-weighted imaging (DWI) is known to be prone to artifacts related to motion originating from subject movement, cardiac pulsation, and breathing, but also to mechanical issues such as table vibrations. Given the necessity for rigorous quality control and motion correction, users are often left to use simple heuristics to select correction schemes, which involves simple qualitative viewing of the set of DWI data, or the selection of transformation parameter thresholds for detection of motion outliers. The scientific community offers strong theoretical and experimental work on noise reduction and orientation distribution function (ODF) reconstruction techniques for HARDI data, where post-acquisition motion correction is widely performed, e.g., using the open-source DTIprep software (1), FSL (the FMRIB Software Library) (2), or TORTOISE (3). Nonetheless, effects and consequences of the selection of motion correction schemes on the final analysis, and the eventual risk of introducing confounding factors when comparing populations, are much less known and far beyond simple intuitive guessing. Hence, standard users lack clear guidelines and recommendations in practical settings. This paper reports a comprehensive evaluation framework to systematically assess the outcome of different motion correction choices commonly used by the scientific community on different DWI-derived measures. We make use of human brain HARDI data from a well-controlled motion experiment to simulate various degrees of motion corruption and noise contamination. Choices for correction include exclusion/scrubbing or registration of motion corrupted directions with different choices of interpolation, as well as the option of interpolation of all directions. The comparative evaluation is based on a study of the impact of motion correction using four metrics that quantify (1) similarity of fiber orientation distribution functions (fODFs), (2) deviation of local fiber orientations, (3) global

  1. Subject-Motion Correction in HARDI Acquisitions: Choices and Consequences.

    PubMed

    Elhabian, Shireen; Gur, Yaniv; Vachet, Clement; Piven, Joseph; Styner, Martin; Leppert, Ilana R; Pike, G Bruce; Gerig, Guido

    2014-01-01

    Diffusion-weighted imaging (DWI) is known to be prone to artifacts related to motion originating from subject movement, cardiac pulsation, and breathing, but also to mechanical issues such as table vibrations. Given the necessity for rigorous quality control and motion correction, users are often left to use simple heuristics to select correction schemes, which involves simple qualitative viewing of the set of DWI data, or the selection of transformation parameter thresholds for detection of motion outliers. The scientific community offers strong theoretical and experimental work on noise reduction and orientation distribution function (ODF) reconstruction techniques for HARDI data, where post-acquisition motion correction is widely performed, e.g., using the open-source DTIprep software (1), FSL (the FMRIB Software Library) (2), or TORTOISE (3). Nonetheless, effects and consequences of the selection of motion correction schemes on the final analysis, and the eventual risk of introducing confounding factors when comparing populations, are much less known and far beyond simple intuitive guessing. Hence, standard users lack clear guidelines and recommendations in practical settings. This paper reports a comprehensive evaluation framework to systematically assess the outcome of different motion correction choices commonly used by the scientific community on different DWI-derived measures. We make use of human brain HARDI data from a well-controlled motion experiment to simulate various degrees of motion corruption and noise contamination. Choices for correction include exclusion/scrubbing or registration of motion corrupted directions with different choices of interpolation, as well as the option of interpolation of all directions. The comparative evaluation is based on a study of the impact of motion correction using four metrics that quantify (1) similarity of fiber orientation distribution functions (fODFs), (2) deviation of local fiber orientations, (3) global

  2. Determining camera parameters for round glassware measurements

    NASA Astrophysics Data System (ADS)

    Baldner, F. O.; Costa, P. B.; Gomes, J. F. S.; Filho, D. M. E. S.; Leta, F. R.

    2015-01-01

    Nowadays there are many types of accessible cameras, including digital single lens reflex ones. Although these cameras are not usually employed in machine vision applications, they can be an interesting choice. However, these cameras have many available parameters to be chosen by the user and it may be difficult to select the best of these in order to acquire images with the needed metrological quality. This paper proposes a methodology to select a set of parameters that will supply a machine vision system with the needed quality image, considering the measurement required of a laboratory glassware.

  3. Fitting observed and theoretical choices - women's choices about prenatal diagnosis of Down syndrome.

    PubMed

    Seror, Valerie

    2008-05-01

    Choices regarding prenatal diagnosis of Down syndrome - the most frequent chromosomal defect - are particularly relevant to decision analysis, since women's decisions are based on the assessment of their risk of carrying a child with Down syndrome, and involve tradeoffs (giving birth to an affected child vs procedure-related miscarriage). The aim of this study, based on face-to-face interviews with 78 women aged 25-35 with prior experience of pregnancy, was to compare the women' expressed choices towards prenatal diagnosis with those derived from theoretical models of choice (expected utility theory, rank-dependent theory, and cumulative prospect theory). The main finding obtained in this study was that the cumulative prospect model fitted the observed choices best: both subjective transformation of probabilities and loss aversion, which are basic features of the cumulative prospect model, have to be taken into account to make the observed choices consistent with the theoretical ones. PMID:17806133

  4. "The choice for death" and neurology.

    PubMed

    Durnová, Anna; Gottweis, Herbert

    2010-07-01

    In the last decade, "end-of-life" issues have gained prominence in political and social debates in many countries. The deliberate ending of the life of a patient upon his/her own request has become a hotly contested topic. This paper discusses the implications of this debate and of corresponding policy and legal developments for neurology. We discuss the nomenclature of the "choices for death", euthanasia, doctor-assisted suicide and palliative care as well as the social dynamics underlying these developments. We suggest that we need a more nuanced and empirically based understanding of the process of the "choice for death and its implications for medical practice." PMID:20393857

  5. Does Expert Advice Improve Educational Choice?

    PubMed Central

    2015-01-01

    This paper reports evidence that an individual meeting with a study counselor at high school significantly improves the quality of choice of tertiary educational field, as self-assessed 18 months after graduation from college. To address endogeneity, we explore the variation in study counseling practices between schools as an instrumental variable (IV). Following careful scrutiny of the validity of the IV, our results indicate a significant and positive influence of study counseling on the quality of educational choice, foremost among males and those with low educated parents. The overall result is stable across a number of robustness checks. PMID:26692388

  6. Student Choices when Learning with Computer Simulations

    NASA Astrophysics Data System (ADS)

    Podolefsky, Noah S.; Adams, Wendy K.; Wieman, Carl E.

    2009-11-01

    We examine student choices while using PhET computer simulations (sims) to learn physics content. In interviews, students were given questions from the Force Concept Inventory (FCI) and were allowed to choose from 12 computer simulations in order to answer these questions. We investigate students' choices when answering FCI questions with sims. We find that while students' initially choose sims that match problem situations at a surface level, deeper connections may be noticed by students later on. These results inform us on how people may choose education resources when learning on their own.

  7. The psychophysics of uneconomical choice: non-linear reward evaluation by a nectar feeder.

    PubMed

    Nachev, Vladislav; Winter, York

    2012-05-01

    Uneconomical choices by humans or animals that evaluate reward options challenge the expectation that decision-makers always maximize the return currency. One possible explanation for such deviations from optimality is that the ability to sense differences in physical value between available alternatives is constrained by the sensory and cognitive processes for encoding profitability. In this study, we investigated the capacity of a nectarivorous bat species (Glossophaga commissarisi) to discriminate between sugar solutions with different concentrations. We conducted a two-alternative free-choice experiment on a population of wild electronically tagged bats foraging at an array of computer-automated artificial flowers that recorded individual choices. We used a Bayesian approach to fit individual psychometric functions, relating the strength of preferring the higher concentration option to the intensity of the presented stimulus. Psychometric analysis revealed that discrimination ability increases non-linearly with respect to intensity. We combined this result with a previous psychometric analysis of volume perception. Our theoretical analysis of choice for rewards that vary in two quality dimensions revealed regions of parameter combinations where uneconomic choice is expected. Discrimination ability may be constrained by non-linear perceptual and cognitive encoding processes that result in uneconomical choice. PMID:22045545

  8. School Choice and Segregation: "Tracking" Racial Equity in Magnet Schools

    ERIC Educational Resources Information Center

    Davis, Tomeka M.

    2014-01-01

    Three arguments regarding racial equity have arisen in the school choice debate. Choice advocates charge that choice will improve access to quality schools for disadvantaged minority students (Chubb & Moe 1990; Coons & Sugarman, 1978; Godwin & Kemerer, 2002; Viteritti, 1999). Critics argue that choice is unlikely to benefit minority…

  9. School Choice: The Struggle for the Soul of American Education.

    ERIC Educational Resources Information Center

    Cookson, Peter W., Jr.

    This discussion of school choice places the issue in its historical and contemporary contexts, describes the major choice plans through case studies, analyzes the outcomes of school choice, and examines the underlying assumptions of the market model of educational reform. School choice is one method by which public education can be reinvented, as…

  10. The ABCs of School Choice, 2009-2010 Edition

    ERIC Educational Resources Information Center

    Friedman Foundation for Educational Choice, 2010

    2010-01-01

    This publication presents the 2009-2010 edition of the Friedman Foundation for Educational Choice's "ABCs of School Choice". The "ABCs of School Choice" provides the latest in up-to-date and accurate information about the many school choice success stories taking place throughout the country. Readers will find this guide an essential resource on…

  11. School Choice Signals: Research Review and Survey Experiments

    ERIC Educational Resources Information Center

    Carpenter, Dick M., II

    2014-01-01

    For the past several decades, a perennial topic on surveys about education has been school choice. Interest in public opinion about choice is more than just "nice to know." The results are often used to support or oppose choice in general or specific choice initiatives under consideration or adopted by state legislatures and even school…

  12. School Choice in America: The Great Debate. Hot Topics Series.

    ERIC Educational Resources Information Center

    Metcalf, Kim K., Ed.; Muller, Patricia A., Ed.; Legan, Natalie A., Ed.

    This document strives to answer questions about school choice, such as What does school choice mean?, What does school choice look like?, and What are the likely consequences of giving parents greater voice in their children's education? Reports are grouped into three thematic chapters. In chapter 1, "Public-Public Choice," reports include:…

  13. The Discourse of School Choice in the United States.

    ERIC Educational Resources Information Center

    Bhagavan, Manu

    1996-01-01

    School systems offer unlimited choice, controlled choice, or no choice. Concerns about school choice include what happens to those left behind, whether teacher autonomy is limited by emphasis on the most popular methods, focus on advertising/competition rather than educational substance, and further balkanization of the nation. (SK)

  14. Misrepresenting "Choice Biographies"?: A Reply to Woodman

    ERIC Educational Resources Information Center

    Roberts, Steven

    2010-01-01

    This paper provides a reply to Woodman's (2009) recent argument that youth studies often incorrectly attribute the concept of "choice biographies" to the work of Ulrich Beck. Drawing heavily on Beck's own words, this paper contends that youth researchers might not be making this association unduly. Consideration is paid to some conceptual issues…

  15. Queer Decisions? Gay Male Students' University Choices

    ERIC Educational Resources Information Center

    Taulke-Johnson, Richard

    2010-01-01

    This article examines the reported influences on the university choices of 17 gay male undergraduate students attending a UK institution. It is argued that this process is strongly mediated by, and, therefore, has to be considered in relation to, class. Data analysis provides insight into the factors gay students say are important in selecting…

  16. Educational Choice: New Roles for Board Members.

    ERIC Educational Resources Information Center

    Randall, Ruth E.

    1990-01-01

    School board members' new leadership roles in planning and implementing school choice programs are described in this article, which draws on the experience of a former Minnesota Commissioner of Education. The first task of the board is to set high expectations in the district and to establish specific policies. Despite the extent of…

  17. Language Choice among Iranians in Sweden

    ERIC Educational Resources Information Center

    Namei, Shidrokh

    2008-01-01

    This study explores the language choice among Iranians in Sweden, both inside and outside the home domain. The data are collected from 188 participants through structured interviews and questionnaires. The results show that Persian is the main instrument of communication in the home domain between parents and children. However, some Swedish is…

  18. Private Schooling and Equity: Dilemmas of Choice.

    ERIC Educational Resources Information Center

    Cookson, Peter W., Jr.

    1991-01-01

    Identifies some of the salient characteristics of American private schools. Examines possible effects that the status composition of the student body might have in influencing the educational opportunity structure. Raises questions about the educational and social equity of supporting private schools financially through school choice mechanisms…

  19. Gender and Choice in Education and Occupation.

    ERIC Educational Resources Information Center

    Radford, John, Ed.

    Nine chapters present cutting-edge research on "brainsex" and its effects on personality, education, and choice. It targets concepts such as job attributes, work flexibility, long-term life planning, home-work conflict, prestige versus occupational interest, and intrinsic motivational mechanisms to explain the relative failure of intervention…

  20. Language Choice on soc.culture.punjab.

    ERIC Educational Resources Information Center

    Paolillo, John C.

    1996-01-01

    Examines factors influencing language choice on the newsgroup soc.culture.punjab, a forum discussing the culture of the Punjab region of India and Pakistan. Finds that Punjabi is used only with interlocutors who are Punjabi community members. Accounts for limited usage in terms of intergenerational language shift, cultural ambivalence among…

  1. Motivating Readers through Voice and Choice

    ERIC Educational Resources Information Center

    Ranck-Buhr, Wendy, Ed.

    2012-01-01

    As both a teacher and a parent, Ranck-Buhr knows a little something about working with students and keeping them engaged in the reading and writing processes... even recalling a son who was a reluctant book-report writer until he was offered some choice of reading material. She suggests practical ways to implement two vital elements in the…

  2. Story Structures in Children's Book Choices.

    ERIC Educational Resources Information Center

    Sebesta, Sam L.; And Others

    A study was conducted to discover the components of books that children prefer over and above those children's books that adults critically acclaim. Forty intermediate-level fiction books included in the "Children's Choices" listings for 1978 to 1980 were read by three adult researchers and classified according to A. Applebee's taxonomy of story…

  3. Understanding Adolescent Contraceptive Choice: An Empirical Test.

    ERIC Educational Resources Information Center

    Adler, Nancy E.; And Others

    Research using expectancy models has shown contraceptive choice among adults to be a rational process in that intentions and behaviors reflect an individual's beliefs, values, attitudes, and perceptions of social norms. This study examined whether such an approach could accurately represent adolescents' contraceptive decision-making. It used the…

  4. Elementary Magnet School Students' Interracial Interaction Choices.

    ERIC Educational Resources Information Center

    Dickinson, Gerald B.; Holifield, Mitchell L.; Holifield, Glenda; Creer, Donna Grady

    2000-01-01

    Investigated elementary students' interracial interaction preferences in four desegregated, urban magnet schools. Data from a sociogram of students' working, playing, and sitting choices indicated that black students were less willing than white students to interact. Racial considerations were more pronounced among girls. There was no trend toward…

  5. Code Choice in the Language Classroom

    ERIC Educational Resources Information Center

    Levine, Glenn S.

    2011-01-01

    Code Choice in the Language Classroom argues that the foreign language classroom is and should be regarded as a multilingual community of practice rather than as a perpetually deficient imitator of an exclusive second-language environment. From a sociocultural and ecological perspective, Levine guides the reader through a theoretical, empirical,…

  6. Personality Factors and Occupational Specialty Choice.

    ERIC Educational Resources Information Center

    Borges, Nicole J.; Jones, Bonnie J.

    This study is a continuation of an earlier investigation of personality and medical specialty choice. The earlier study determined that personality differences existed among family practitioners, anesthesiologists, and general surgeons. Based on this initial research, an attempt was made to answer the question of how the personality factors of…

  7. Multiple Choice: Trends in Dining Design.

    ERIC Educational Resources Information Center

    Swanquist, Barry

    1999-01-01

    Examines changes in the traditional school dining hall and the prevailing trends in food-service design. Explores dining-hall space flexibility and multi-functionality and the need to cater to student preferences for brand names and choice. (GR)

  8. Moral Choices in Contemporary Society: Source Book.

    ERIC Educational Resources Information Center

    Hellman, Mary, Ed.

    One of several supplementary materials for a newspaper course on moral choices in contemporary society, this sourcebook contains program ideas and resources to help civic leaders and educators plan programs based on the course topics. There are four sections. The first section explains how the topics can be used in planning programs, identifies…

  9. Choices and Motivations of Infertile Couples.

    ERIC Educational Resources Information Center

    van Balen, Frank; Verdurmen, Jacqueline; Ketting, Evert

    1997-01-01

    Infertile couples' (N=131) consideration of options for dealing with infertility (medical help, adoption, fostering, alternative medicine, and focusing on other life goals) is studied. Options were related to specific motivations including altruistic motives for adoption or foster care. Results, timing of choices, and motivations are discussed.…

  10. Choice, SES Would Flip under Plan

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2006-01-01

    This article reports the plan of the U.S. Department of Education to expand a pilot initiative that would flip the order of key consequences for schools' low academic performance under the No Child Left Behind Act. Building on an initiative piloted in Virginia for school year 2006-2007, participating districts could offer a choice of supplemental…

  11. Neural Correlates of Affective Influence on Choice

    ERIC Educational Resources Information Center

    Piech, Richard M.; Lewis, Jade; Parkinson, Caroline H.; Owen, Adrian M.; Roberts, Angela C.; Downing, Paul E.; Parkinson, John A.

    2010-01-01

    Making the right choice depends crucially on the accurate valuation of the available options in the light of current needs and goals of an individual. Thus, the valuation of identical options can vary considerably with motivational context. The present study investigated the neural structures underlying context dependent evaluation. We instructed…

  12. Teaching, Communication, and Book Choice Processes

    ERIC Educational Resources Information Center

    Ryan, Dana Marie

    2013-01-01

    Allowing students to select their own books for independent reading has been linked to increased reading engagement, heightened motivation to read, and greater independence and efficacy in reading. However, there has been little exploration of the processes surrounding book choice in elementary classrooms, particularly teaching practices that…

  13. Evolutionary pressures on primate intertemporal choice.

    PubMed

    Stevens, Jeffrey R

    2014-07-01

    From finding food to choosing mates, animals must make intertemporal choices that involve fitness benefits available at different times. Species vary dramatically in their willingness to wait for delayed rewards. Why does this variation across species exist? An adaptive approach to intertemporal choice suggests that time preferences should reflect the temporal problems faced in a species's environment. Here, I use phylogenetic regression to test whether allometric factors relating to body size, relative brain size and social group size predict how long 13 primate species will wait in laboratory intertemporal choice tasks. Controlling for phylogeny, a composite allometric factor that includes body mass, absolute brain size, lifespan and home range size predicted waiting times, but relative brain size and social group size did not. These findings support the notion that selective pressures have sculpted intertemporal choices to solve adaptive problems faced by animals. Collecting these types of data across a large number of species can provide key insights into the evolution of decision making and cognition. PMID:24827445

  14. Evolutionary pressures on primate intertemporal choice

    PubMed Central

    Stevens, Jeffrey R.

    2014-01-01

    From finding food to choosing mates, animals must make intertemporal choices that involve fitness benefits available at different times. Species vary dramatically in their willingness to wait for delayed rewards. Why does this variation across species exist? An adaptive approach to intertemporal choice suggests that time preferences should reflect the temporal problems faced in a species's environment. Here, I use phylogenetic regression to test whether allometric factors relating to body size, relative brain size and social group size predict how long 13 primate species will wait in laboratory intertemporal choice tasks. Controlling for phylogeny, a composite allometric factor that includes body mass, absolute brain size, lifespan and home range size predicted waiting times, but relative brain size and social group size did not. These findings support the notion that selective pressures have sculpted intertemporal choices to solve adaptive problems faced by animals. Collecting these types of data across a large number of species can provide key insights into the evolution of decision making and cognition. PMID:24827445

  15. Freedom and Learning: The Need for Choice

    ERIC Educational Resources Information Center

    Goodman, Paul

    1973-01-01

    Argues that the young can be educated entirely in terms of their free choice, with no processing whatsoever. Suggests that most of the money now spent for high schools and colleges should be devoted to the support of apprenticeships, travel, subsidized browsing in libraries, and self-directed study and research; and to support other volunteer…

  16. Career Path Guide for Adult Career Choices.

    ERIC Educational Resources Information Center

    Case, Clydia

    Intended for adults who are considering career choices or changes, this booklet provides opportunities for self-study and reflection in six career paths. The booklet begins with tips for long-term career survival and myths and realities of career planning. After a brief career survey, readers are introduced to six career paths: arts and…

  17. Interpersonal Choice and Networks in China.

    ERIC Educational Resources Information Center

    Blau, Peter M.; And Others

    1991-01-01

    The microstructures of interpersonal networks in China and the United States contain many consistent patterns, despite the countries' great differences. In-group choices and network diversity are analyzed with regard to age, sex, educational attainment, occupation, socioeconomic status, and proportion of kin in the network. Contains 21 references…

  18. More Choices, Higher Scores, and Worse Education

    ERIC Educational Resources Information Center

    American Educator, 2010

    2010-01-01

    If there is one thing all educators know and many studies have confirmed for decades, it is that there is no single answer to educational improvement. There are no grounds for the claim made in the past decade that accountability all by itself is a silver bullet, nor for the oft-asserted argument that choice by itself is a panacea. This article…

  19. Mate Choice: Charting Desire's Tangled Bank.

    PubMed

    Rosenthal, Gil G

    2016-04-01

    Choosing a mate requires a way to turn sexual arousal into sexual action. A recent paper identifies a hormone receptor that acts as a molecular gatekeeper in reproductive decisions. Focusing on mate-choice mechanisms may clarify longstanding evolutionary puzzles in sexual selection and speciation. PMID:27046819

  20. Making Choices: Life Skills for Adolescents. Curriculum.

    ERIC Educational Resources Information Center

    Halter, Mary H.; Lang, Barbara Fierro

    This text was designed to help adolescents develop skills which will encourage them to make healthy and positive choices about life. In addition, its design will assist adults, parents and teachers, as they guide young people through the process. The book uses a series of written exercises designed to help organize the students' goals and…

  1. Women and the Choice to Study Economics

    ERIC Educational Resources Information Center

    Emerson, Tisha L. N.; McGoldrick, KimMarie; Mumford, Kevin J.

    2012-01-01

    Underrepresentation of women in economics is documented in many studies. Investigation of its sources at the undergraduate level is examined through students' decisions to persist in economics, either beyond an introductory course or in their major choices. The authors add to the literature by analyzing students' decisions to take their first…

  2. Matching, Demand, Maximization, and Consumer Choice

    ERIC Educational Resources Information Center

    Wells, Victoria K.; Foxall, Gordon R.

    2013-01-01

    The use of behavioral economics and behavioral psychology in consumer choice has been limited. The current study extends the study of consumer behavior analysis, a synthesis between behavioral psychology, economics, and marketing, to a larger data set. This article presents the current work and results from the early analysis of the data. We…

  3. Why Choice Is Good for Teachers

    ERIC Educational Resources Information Center

    Ferrero, David J.

    2004-01-01

    Traditionalists and progressives coexist warily in today's public schools, creating fragmented institutions with no common ethos. Letting teachers start their own schools may bring an end to the pedagogical holy wars. School choice actually has the potential to enhance professionalism and collegiality among teachers by allowing them to form…

  4. Financing Education in Ontario: Issues and Choices.

    ERIC Educational Resources Information Center

    Bird, Richard M.

    A study of the history of public financing of elementary and secondary education in Ontario and the issues and choices presently facing the province's finance system suggest that proposals for radical change must be considered. Current pressures on the mixed provincial-local system of finance come from the slow rate of economic expansion generally…

  5. Choice Shift in Opinion Network Dynamics

    NASA Astrophysics Data System (ADS)

    Gabbay, Michael

    Choice shift is a phenomenon associated with small group dynamics whereby group discussion causes group members to shift their opinions in a more extreme direction so that the mean post-discussion opinion exceeds the mean pre-discussion opinion. Also known as group polarization, choice shift is a robust experimental phenomenon and has been well-studied within social psychology. In opinion network models, shifts toward extremism are typically produced by the presence of stubborn agents at the extremes of the opinion axis, whose opinions are much more resistant to change than moderate agents. However, we present a model in which choice shift can arise without the assumption of stubborn agents; the model evolves member opinions and uncertainties using coupled nonlinear differential equations. In addition, we briefly describe the results of a recent experiment conducted involving online group discussion concerning the outcome of National Football League games are described. The model predictions concerning the effects of network structure, disagreement level, and team choice (favorite or underdog) are in accord with the experimental results. This research was funded by the Office of Naval Research and the Defense Threat Reduction Agency.

  6. From School Choice to Student Voice.

    ERIC Educational Resources Information Center

    Heckman, Paul E.; Montera, Viki L.

    2001-01-01

    Educational mass marketing approaches are like fast-food franchises; they offer homogeneous, standardized products that cannot satisfy every consumer's needs. A niche market looks inside the masses to address more individual, specialized choices missing from the menu. Variability, not uniformity, should guide development of public schooling. (MLH)

  7. Modeling Choice and Valuation in Decision Experiments

    ERIC Educational Resources Information Center

    Loomes, Graham

    2010-01-01

    This article develops a parsimonious descriptive model of individual choice and valuation in the kinds of experiments that constitute a substantial part of the literature relating to decision making under risk and uncertainty. It suggests that many of the best known "regularities" observed in those experiments may arise from a tendency for…

  8. Choice of For-Profit College

    ERIC Educational Resources Information Center

    Chung, Anna S.

    2012-01-01

    In this paper I investigate whether students self-select into the U.S. for-profit colleges or whether the choice of for-profit sector is accidental or due to the reasons external to the students (geographic exposure to for-profit providers, tuition pricing, or random circumstances). The main student-level data samples come from the National…

  9. Race, Inequality of Opportunity, and School Choice

    ERIC Educational Resources Information Center

    Darby, Derrick; Saatcioglu, Argun

    2015-01-01

    Both neoliberals and liberals call for mitigating inequality of educational opportunity stemming from circumstances beyond an individual's control. In this article, we challenge the wisdom of making equality of opportunity hinge on emphasizing the distinction rather than the relationship between choices and circumstances. We utilize an empirical…

  10. Unconscious Factors in Choice of a Mate

    ERIC Educational Resources Information Center

    Ottenheimer, Lilly

    1971-01-01

    If the selection of a spouse is based on the unconscious wish to correct disturbances which previously existed in the parent child relationship, the marriage is threatened from the start. This article examines motivations derived from early developmental phases which form convictions which later become the nucleus for mate choice. (Author/CJ)

  11. Choice, Conditioned Reinforcement, and the Prius Effect

    ERIC Educational Resources Information Center

    Fantino, Edmund

    2008-01-01

    Psychologists have long been intrigued with the rationales that underlie our decisions. Similarly, the concept of conditioned reinforcement has a venerable history, particularly in accounting for behavior not obviously maintained by primary reinforcers. The studies of choice and of conditioned reinforcement have often developed in lockstep. Many…

  12. Educational "Choice" (Vouchers) and Social Mobility.

    ERIC Educational Resources Information Center

    Manski, Charles F.

    1992-01-01

    Uses a model of student and school behavior to simulate effects of differing voucher amounts on students in different income categories, drawing on two major assumptions concerning service delivery and competition. Poor youngsters would not be better off under voucher system. Even under highly favorable conditions, a systemic choice system would…

  13. Doing School Choice Right: Preliminary Findings

    ERIC Educational Resources Information Center

    Harvey, James; Hill, Paul T.

    2006-01-01

    The Center on Reinventing Public Education (CRPE) has launched a new initiative entitled "Doing School Choice Right." Funded by the Bill and Melinda Gates, Annie E. Casey, and Lynde and Harry Bradley Foundations, the initiative's goal is to help state and local leaders handle practical issues whose resolution can determine whether school choice…

  14. Incentives, Choice, Education and Well-Being

    ERIC Educational Resources Information Center

    Schwartz, Barry

    2009-01-01

    It is a truism that giving people multiple reasons to engage in some activity will increase the chances of that activity--that two reasons are better than one. It is another truism, in the developed, Western world, that more freedom brings more well-being, and that more choice brings more freedom. In education, these truisms have led to the use of…

  15. School Choice and State Constitutions' Religion Clauses

    ERIC Educational Resources Information Center

    Komer, Richard D.

    2009-01-01

    After the U.S. Supreme Court's decision in "Zelman v. Simmons-Harris," only state religion clauses represent a potential constitutional bar to the inclusion of religious options in properly designed school choice programs. The two most significant are compelled support clauses and Blaine Amendments. Both are frequently misinterpreted by state…

  16. Choice and privatisation in Swedish primary care.

    PubMed

    Anell, Anders

    2011-10-01

    In 2007, a new wave of local reforms involving choice for the population and privatisation of providers was initiated in Swedish primary care. Important objectives behind reforms were to strengthen the role of primary care and to improve performance in terms of access and responsiveness. The purpose of this article was to compare the characteristics of the new models and to discuss changes in financial incentives for providers and challenges regarding governance from the part of county councils. A majority of the models being introduced across the 21 county councils can best be described as innovative combinations between a comprehensive responsibility for providers and significant degrees of freedom regarding choice for the population. Key financial characteristics of fixed payment and comprehensive financial responsibility for providers may create financial incentives to under-provide care. Informed choices by the population, in combination with reasonably low barriers for providers to enter the primary care market, should theoretically counterbalance such incentives. To facilitate such competition is indeed a challenge, not only because of difficulties in implementing informed choices but also because the new models favour large and/or horizontally integrated providers. To prevent monopolistic behaviour, county councils may have to accept more competition as well as more governance over clinical practice than initially intended. PMID:20701829

  17. Pricing Policy and the College Choice Process.

    ERIC Educational Resources Information Center

    Chapman, Randall G.

    1979-01-01

    A marketing management paradigm for academe is discussed along with aspects of the pricing policy process. The two most important factors affecting the college choice process are shown to be college quality and price-related considerations. Implications for marketing are discussed. (Author/LBH)

  18. Career Choices Among Saudi Medical Students.

    ERIC Educational Resources Information Center

    Al-Faris, Eiad; And Others

    1997-01-01

    A survey of 253 final-year students at the four Saudi medical schools found the most frequently-chosen specialties were internal medicine, surgery, pediatrics, and obstetrics/gynecology. Over one-fourth were unsure of career choice. Gender differences were found. Most common locations for postgraduate training were Saudi Arabia and Canada, and a…

  19. Modeling Spanish Mood Choice in Belief Statements

    ERIC Educational Resources Information Center

    Robinson, Jason R.

    2013-01-01

    This work develops a computational methodology new to linguistics that empirically evaluates competing linguistic theories on Spanish verbal mood choice through the use of computational techniques to learn mood and other hidden linguistic features from Spanish belief statements found in corpora. The machine learned probabilistic linguistic models…

  20. Behavioural Approaches to Understanding Student Choice

    ERIC Educational Resources Information Center

    Diamond, Abigail; Vorley, Tim; Roberts, Jennifer; Jones, Stephen

    2012-01-01

    The Higher Education Academy (HEA), in partnership with the National Union of Students (NUS), commissioned CFE and The University of Sheffield to undertake research to explore behavioural approaches to understanding student choice. Within the research, the authors' applied insights from behavioural economics to help aid understanding of student…

  1. Program to Combat Stereotyping in Career Choice.

    ERIC Educational Resources Information Center

    Harrison, Laurie R.

    Divided into three sections which deal with sex, race, and handicap stereotyping in career choice, the twenty-eight programs described here attempt to combat stereotypes among students and/or staff (K-12). Most descriptions list the goals of the program, target population, staffing and management, facilities and activities, program effectiveness…

  2. Behaviors, Noncognitive Skills, and School Choice

    ERIC Educational Resources Information Center

    Mills, Jonathan N.

    2013-01-01

    While choice opponents and proponents tend to focus on how programs impact achievement, the growing body of research indicating a strong relationship between future outcomes and noncognitive skills indicates a need to broaden the basis for assessing programs. This article synthesizes the existing literature on the development of noncognitive…

  3. Restricted Liberty, Parental Choice and Homeschooling

    ERIC Educational Resources Information Center

    Merry, Michael S.; Karsten, Sjoerd

    2010-01-01

    In this paper the authors carefully study the problem of liberty as it applies to school choice, and whether there ought to be restricted liberty in the case of homeschooling. They examine three prominent concerns that might be brought against homeschooling, viz., that it aggravates social inequality, worsens societal conflict and works against…

  4. The Impact of America's Choice Design

    ERIC Educational Resources Information Center

    Cox, Devonda Kaye

    2010-01-01

    This study reviewed the effects of change, fatigue and transformation of low-performing schools while implementing an instructional Design rather than an instructional program. The study investigated the relationship of the America's Choice, Inc. schools with the configuration of the grades 6-8 scores compared to the scores of the state average…

  5. School Choice Litigation after "Zelman" and "Locke"

    ERIC Educational Resources Information Center

    Liekweg, John A.

    2004-01-01

    In the past 2 years, the United States Supreme Court has decided two important cases that will bear directly on legislation and litigation involving school choice programs that provide financial aid to parents of children attending religious schools. Those cases are "Zelman v. Simmons-Harris" (2002) and "Locke v. Davey" (2004). The reasoning in…

  6. Formatting Issues in Multiple Choice Tests.

    ERIC Educational Resources Information Center

    Siskind, Theresa G.; And Others

    The purposes of the present study were to ascertain whether or not two particular formatting characteristics influenced seventh grade student performance on math tests. One research question focused on the effects of decimal positioning in multiple choice options for computational items. In a second question, labeling format was compared with…

  7. Lesher Middle School: Commitment by Choice

    ERIC Educational Resources Information Center

    Principal Leadership, 2012

    2012-01-01

    This article features Lesher Middle School, a school of choice, as are all of the schools in the Poudre School District in Ft. Collins, Colorado. In 2004, it was a traditional junior high school with a declining enrollment that housed an application-based International Baccalaureate Middle Years Programme (IB MYP) that resulted in tracking…

  8. Addiction and Choice: Theory and New Data

    PubMed Central

    Heyman, Gene M.

    2013-01-01

    Addiction’s biological basis has been the focus of much research. The findings have persuaded experts and the public that drug use in addicts is compulsive. But the word “compulsive” identifies patterns of behavior, and all behavior has a biological basis, including voluntary actions. Thus, the question is not whether addiction has a biology, which it must, but whether it is sensible to say that addicts use drugs compulsively. The relevant research shows most of those who meet the American Psychiatric Association’s criteria for addiction quit using illegal drugs by about age 30, that they usually quit without professional help, and that the correlates of quitting include legal concerns, economic pressures, and the desire for respect, particularly from family members. That is, the correlates of quitting are the correlates of choice not compulsion. However, addiction is, by definition, a disorder, and thereby not beneficial in the long run. This is precisely the pattern of choices predicted by quantitative choice principles, such as the matching law, melioration, and hyperbolic discounting. Although the brain disease model of addiction is perceived by many as received knowledge it is not supported by research or logic. In contrast, well established, quantitative choice principles predict both the possibility and the details of addiction. PMID:23653607

  9. Does Challenge by Choice Increase Participation?

    ERIC Educational Resources Information Center

    Chase, Daniel L.

    2015-01-01

    Challenge by choice (CBC) has been regarded as a foundational principle for challenge ropes course programs. Although CBC is widely accepted as the primary mechanism for facilitating intended ropes course outcomes, especially a participant's involvement, until recently it had remained an untested assumption. This study explored the role of CBC as…

  10. The Probabilistic Nature of Preferential Choice

    ERIC Educational Resources Information Center

    Rieskamp, Jorg

    2008-01-01

    Previous research has developed a variety of theories explaining when and why people's decisions under risk deviate from the standard economic view of expected utility maximization. These theories are limited in their predictive accuracy in that they do not explain the probabilistic nature of preferential choice, that is, why an individual makes…

  11. Subjects of Choice and Lifelong Learning

    ERIC Educational Resources Information Center

    Bansel, Peter

    2007-01-01

    This paper addresses some of the discursive practices of neoliberal government through which the subject is constituted as a subject of choice--subjects whose life trajectory is shaped by the imperatives of a labour market in which they will become mobile and flexible workers with multiple careers and jobs. Mobility among these multiple careers…

  12. School Superintendents' Choices of Professional Periodicals.

    ERIC Educational Resources Information Center

    Mayo, C. Russell; Zirkel, Perry A.

    2002-01-01

    Reports results of national survey of superintendents' top reading choices from a list of 34 periodicals in educational leadership. Superintendents' top-ranked periodicals are "Educational Leadership,""Phi Delta Kappan,""School Administrator," and "American School Board Journal." (Contains 24 references.) (PKP)

  13. Handbook of Research on School Choice

    ERIC Educational Resources Information Center

    Berends, Mark, Ed.; Springer, Matthew G., Ed.; Ballou, Dale, Ed.; Walberg, Herbert J., Ed.

    2009-01-01

    Since the early 1990s when the nation's first charter school was opened in Minneapolis, the scope and availability of school-based options to parents has steadily expanded. No longer can public education be characterized as a monopoly. Sponsored by the National Center on School Choice (NCSC), this handbook makes readily available the most rigorous…

  14. 2012 ABCs of School Choice: Rising Tide

    ERIC Educational Resources Information Center

    DiPerna, Paul, Ed.

    2012-01-01

    School choice is a common sense idea that gives all parents the power and freedom to choose their child's education, while encouraging healthy competition among schools and other institutions to better serve students' needs and priorities. It is a public policy that allows a parent/guardian or student to choose a district, charter, or private…

  15. School Choice Evidence and Its Significance

    ERIC Educational Resources Information Center

    Merrifield, John

    2008-01-01

    Pressing questions about the merits of full-fledged market accountability in K-12 education, and more limited choice programs, have spawned a large scholarly literature. This article assesses what we know from the most prominent studies and the importance of those findings to school system reform discussions. The studies most widely cited in the…

  16. Explaining Language Choice in Early Infant Bilingualism.

    ERIC Educational Resources Information Center

    Quay, Suzanne

    This study investigated whether language context affects language choice in a Spanish-English bilingual infant from age 1;3 to 1;10. Most studies of child bilingualism assume that communicative competence occurs at a stage in language development after the onset of syntactic constructions, but this paper hypothesizes that once the child begins to…

  17. Constructing Motivation through Choice, Interest, and Interestingness

    ERIC Educational Resources Information Center

    Patall, Erika A.

    2013-01-01

    Psychological research and theory have traditionally suggested that opportunities for choosing will lead to motivation and performance benefits. However, evidence on choice effects has not been ubiquitously positive, and recent investigations have revealed factors that diminish or reverse the effects of choosing. This investigation sought to…

  18. Choice: A Thematic Sequence of English Units.

    ERIC Educational Resources Information Center

    Institute for Services to Education, Inc., Washington, DC.

    One of a series of volumes containing units on specific themes designed for use in college freshman English courses, this particular volume considers the issue of choice through literature (short stories, novels, and poems). A section describing chamber theatre technique, which is an integral part of many of the units in this sequence, is…

  19. Action and valence modulate choice and choice-induced preference change.

    PubMed

    Koster, Raphael; Duzel, Emrah; Dolan, Raymond J

    2015-01-01

    Choices are not only communicated via explicit actions but also passively through inaction. In this study we investigated how active or passive choice impacts upon the choice process itself as well as a preference change induced by choice. Subjects were tasked to select a preference for unfamiliar photographs by action or inaction, before and after they gave valuation ratings for all photographs. We replicate a finding that valuation increases for chosen items and decreases for unchosen items compared to a control condition in which the choice was made post re-evaluation. Whether choice was expressed actively or passively affected the dynamics of revaluation differently for positive and negatively valenced items. Additionally, the choice itself was biased towards action such that subjects tended to choose a photograph obtained by action more often than a photographed obtained through inaction. These results highlight intrinsic biases consistent with a tight coupling of action and reward and add to an emerging understanding of how the mode of action itself, and not just an associated outcome, modulates the decision making process. PMID:25747703

  20. GluN2B in corticostriatal circuits governs choice learning and choice shifting

    PubMed Central

    Brigman, Jonathan L.; Daut, Rachel; Wright, Tara; Gunduz-Cinar, Ozge; Graybeal, Carolyn; Davis, Margaret I.; Jiang, Zhihong; Saksida, Lisa; Jinde, Seiichiro; Pease, Matthew; Bussey, Timothy J.; Lovinger, David M.; Nakazawa, Kazu; Holmes, Andrew

    2013-01-01

    A choice that reliably produces a preferred outcome can be automated to liberate cognitive resources for other tasks. Should an outcome become less desirable, behavior must adapt in parallel or become perseverative. Corticostriatal systems are known to mediate choice learning and flexibility, but the molecular mechanisms subserving the instantiation of these processes are not well understood. We integrated mouse behavioral, immunocytochemical, in vivo electrophysiological, genetic, and pharmacological approaches to study choice. We found that the dorsal striatum (DS) was increasingly activated with choice learning, whereas reversal of learned choice engaged prefrontal regions. In vivo, DS neurons showed activity associated with reward anticipation and receipt that emerged with learning and relearning. Corticostriatal or striatal GluN2B gene deletion, or DS-restricted GluN2B antagonism, impaired choice learning, whereas cortical GluN2B deletion or OFC GluN2B antagonism impaired shifting. Our convergent data demonstrate how corticostriatal GluN2B circuits govern the ability to learn and shift choice behavior. PMID:23831965

  1. Action and Valence Modulate Choice and Choice-Induced Preference Change

    PubMed Central

    Koster, Raphael; Duzel, Emrah; Dolan, Raymond J.

    2015-01-01

    Choices are not only communicated via explicit actions but also passively through inaction. In this study we investigated how active or passive choice impacts upon the choice process itself as well as a preference change induced by choice. Subjects were tasked to select a preference for unfamiliar photographs by action or inaction, before and after they gave valuation ratings for all photographs. We replicate a finding that valuation increases for chosen items and decreases for unchosen items compared to a control condition in which the choice was made post re-evaluation. Whether choice was expressed actively or passively affected the dynamics of revaluation differently for positive and negatively valenced items. Additionally, the choice itself was biased towards action such that subjects tended to choose a photograph obtained by action more often than a photographed obtained through inaction. These results highlight intrinsic biases consistent with a tight coupling of action and reward and add to an emerging understanding of how the mode of action itself, and not just an associated outcome, modulates the decision making process. PMID:25747703

  2. An evolutionary firefly algorithm for the estimation of nonlinear biological model parameters.

    PubMed

    Abdullah, Afnizanfaizal; Deris, Safaai; Anwar, Sohail; Arjunan, Satya N V

    2013-01-01

    The development of accurate computational models of biological processes is fundamental to computational systems biology. These models are usually represented by mathematical expressions that rely heavily on the system parameters. The measurement of these parameters is often difficult. Therefore, they are commonly estimated by fitting the predicted model to the experimental data using optimization methods. The complexity and nonlinearity of the biological processes pose a significant challenge, however, to the development of accurate and fast optimization methods. We introduce a new hybrid optimization method incorporating the Firefly Algorithm and the evolutionary operation of the Differential Evolution method. The proposed method improves solutions by neighbourhood search using evolutionary procedures. Testing our method on models for the arginine catabolism and the negative feedback loop of the p53 signalling pathway, we found that it estimated the parameters with high accuracy and within a reasonable computation time compared to well-known approaches, including Particle Swarm Optimization, Nelder-Mead, and Firefly Algorithm. We have also verified the reliability of the parameters estimated by the method using an a posteriori practical identifiability test. PMID:23469172

  3. Accounting for Transport Parameter Uncertainty in Geostatistical Groundwater Contaminant Release History Estimation

    NASA Astrophysics Data System (ADS)

    Ostrowski, J.; Shlomi, S.; Michalak, A.

    2007-12-01

    The process of estimating the release history of a contaminant in groundwater relies on coupling a limited number of concentration measurements with a groundwater flow and transport model in an inverse modeling framework. The information provided by available measurements is generally not sufficient to fully characterize the unknown release history; therefore, an accurate assessment of the estimation uncertainty is required. The modeler's level of confidence in the transport parameters, expressed as pdfs, can be incorporated into the inverse model to improve the accuracy of the release estimates. In this work, geostatistical inverse modeling is used in conjunction with Monte Carlo sampling of transport parameters to estimate groundwater contaminant release histories. Concentration non-negativity is enforced using a Gibbs sampling algorithm based on a truncated normal distribution. The method is applied to two one-dimensional test cases: a hypothetical dataset commonly used in validating contaminant source identification methods, and data collected from a tetrachloroethylene and trichloroethylene plume at the Dover Air Force Base in Delaware. The estimated release histories and associated uncertainties are compared to results from a geostatistical inverse model where uncertainty in transport parameters is ignored. Results show that the a posteriori uncertainty associated with the model that accounts for parameter uncertainty is higher, but that this model provides a more realistic representation of the release history based on available data. This modified inverse modeling technique has many applications, including assignment of liability in groundwater contamination cases, characterization of groundwater contamination, and model calibration.

  4. The impact of gender and working experience on intertemporal choices

    NASA Astrophysics Data System (ADS)

    Lu, Yang; Zhuang, Xintian

    2014-09-01

    Intertemporal choice has been drawing attention in econophysics and neuroeconomics. In this paper, we experimentally estimate the parameters and AICc (Akaike Information Criterion with small sample correction) of intertemporal choice models (exponential, simple hyperbolic, quasi hyperbolic, and q-exponential) for senior undergraduate students and MBA students, respectively. Our results show that (1) regardless of gender or working experience, q-exponential discount model always generates minimum AICc value, and it is thus the optimal discount model; (2) gender affects the degree of inconsistency and fitness of the discount model. Comparing to female participants, male participants have a higher degree of inconsistency while their discount pattern is better explained by q-exponential discount model; (3) working experience has an interaction effect with gender. For male participants, working experience is inversely related to the degree of inconsistency and the fitness of q-exponential discount model. On the contrary, for female participants, working experience is positively related to the degree of inconsistency and the fitness of q-exponential discount model.

  5. Implications of the choice and configuration of hydrologic models on the portrayal of climate change impact

    NASA Astrophysics Data System (ADS)

    Mendoza, P. A.; Clark, M. P.; Rajagopalan, B.; Mizukami, N.; Gutmann, E. D.

    2013-12-01

    Climate change studies involve several methodological choices that impact the hydrological sensitivities obtained. Among these, hydrologic model structure selection and parameter identification are particularly relevant and usually have a strong subjective component. This subjectivity is not only limited to engineering applications, but also extends to many of our research studies, resulting in problems such as missing processes in our models, inappropriate parameterizations and compensatory effects of model parameters. The goal of this research is to identify the role of model structures and parameter values on the assessment of hydrologic sensitivity to climate change. We conduct our study in three basins located in the Colorado Headwaters Region, using four different hydrologic models (PRMS, VIC, Noah and Noah-MP). We first compare both model performance and climate sensitivities using default parameterizations and parameter values calibrated with the Shuffled Complex Evolution algorithm. Our results demonstrate that calibration doesn't necessarily improve the representation of hydrological processes or decrease inter-model differences in the change of signature measures of hydrologic behavior with respect to a future climate scenario. We found that inter-model differences in hydrologic sensitivities to climate change may be larger than the climate change signal even after models have been calibrated. Results demonstrate that both model choice (after calibration) and parameter selection have important effects in the portrayal of climate change impacts, and work is ongoing to identify more robust modeling strategies that explicitly account for the subjectivity in these choices. Location of the basins of interest Hydrological models used in this study

  6. Science with Constellation-X, Choice of Instrumentation

    NASA Technical Reports Server (NTRS)

    Hornscheimeier, Ann; White, Nicholas; Tananbaum, Harvey; Garcia, Michael; Bookbinder, Jay; Petre, Robert; Cottam, Jean

    2007-01-01

    The Constellation X-ray Observatory is one of the two Beyond Einstein Great Observatories and will provide a 100-fold increase in collecting area in high spectral resolving power X-ray instruments over the Chandra and XMM-Newton gratings instruments. The mission has four main science objectives which drive the requirements for the mission. This contribution to the Garmire celebration conference describes these four science areas: Black Holes, Dark Energy, Missing Baryons, and the Neutron Star Equation of State as well as the requirements flow-down that give rise to the choice of instrumentation and implementation for Constellation-X. As we show, each of these science areas place complementary constraints on mission performance parameters such as collecting area, spectral resolving power, timing resolution, and field of view. The mission's capabilities will enable a great breadth of science, and its resources will be open to the community through its General Observer program.

  7. Choices at Space Station End of Life

    NASA Astrophysics Data System (ADS)

    Burke, J. D.; Coderre, K. M.; Dator, J. A.

    Extending International Space Station (ISS) operations will expand the scope for deciding its fate at its end of life. In this paper we examine the choices likely to be available at that distant unknown day when it is decided, for whatever reasons, to bring crew-directed engineering and science operations to a close. Of course a premature accidental termination is possible at any time, and measures to cope with that (and return to normal if possible) should be kept ready and augmented as ISS service capacities improve, but here we do not focus on accidents. Rather, we consider what may be done with an old but functioning spacecraft after it is declared surplus. We use the technique of Futures Studies to look at the choices. Without attempting prediction, futurists develop a set of empirically-based alternate futures, describe the likely consequences of each, and point to preferred outcomes. For the ISS at end of scheduled operation the choices are in three classes: DOWN, STAY, or UP. In the DOWN choice, after possible salvage and transfer of long-running investigations to another (e.g., Chinese-led) international station, the ISS is commanded to descend and burn up. The STAY choice, not viable in the long run, might be chosen to provide time for later decisions, but eventually it would prove impractical to continue re-boosting to maintain the station in Low Earth Orbit (LEO). In the UP choice the ISS is propelled, by heavy-lift boost impulses or a low-thrust spiral-out or a combination of both, into a high orbit with a lifetime of hundreds of years, opening the prospect of a wide variety of options to be compared in search of a preferred longer-term future. The decision to boost the ISS into a high orbit could be completely rational based on any of several arguments, or it could be partly irrational as in the case of the USS Constitution, an eighteenth- century warship saved from the ship-breakers by a poem.

  8. Choice of parameters for linear colliders in multi-bunch mode

    SciTech Connect

    Claus, J.

    1987-01-01

    The energy efficiency of a linear collider in multi-bunch mode is calculated for the case that the bunches in each of the two interacting beams are identical in all interaction points, a configuration which can be realized by taking advantage of the beam-beam effect between beams of opposite electric charge. The maximization of the efficiency is discussed, the maximum appears to increase nearly linearly with beam brightness and accelerating gradient, and about quadratically with the length of the ir. The optimum operating frequency for the linacs increases also, while the pulse repetition rate and the beam current needed for fixed luminosity, decrease. The increasing brightness and the decreasing current needed for higher efficiency lead to smaller transverse spotsizes in the crossing points; this imposes tighter tolerances on the relative transverse coordinates of the two beam-axes. Pillbox or similar resonators, excited in the TM01 mode, may be preferable to quadrupoles for transverse focusing, at the high frequencies and gradients that seem desirable, particularly in the final focus. 4 refs., 7 figs.

  9. Improvement of Arab Digits Recognition Rate Based in the Parameters Choice

    NASA Astrophysics Data System (ADS)

    Hadri, C.; Boughazi, M.; Fezari, M.

    2008-06-01

    Automatic speech recognition (ASR) is the process of automatically recognizing the speech on the basis of information obtained by acoustic features extracted from the speech signal. Because features extraction is the first component in ASR systems, the quality of the later component depends from the quality of feature extractor. The goal of this work is to study and implement features (representations) extraction, which are robust to the differences between the acoustic conditions of training and evolution. These features will be evaluated in an Automatic Arab digits recognition system. A particular attention will be taken to the robust features extraction methods (CMS, CGN, RASTAPLP, MBLPCC, and LPC MFCC).

  10. Redefining solubility parameters: the partial solvation parameters.

    PubMed

    Panayiotou, Costas

    2012-03-21

    The present work reconsiders a classical and universally accepted concept of physical chemistry, the solubility parameter. Based on the insight derived from modern quantum chemical calculations, a new definition of solubility parameter is proposed, which overcomes some of the inherent restrictions of the original definition and expands its range of applications. The original single solubility parameter is replaced by four partial solvation parameters reflecting the dispersion, the polar, the acidic and the basic character of the chemical compounds as expressed either in their pure state or in mixtures. Simple rules are adopted for the definition and calculation of these four parameters and their values are tabulated for a variety of common substances. In contrast, however, to the well known Hansen solubility parameters, their design and evaluation does not rely exclusively on the basic rule of "similarity matching" for solubility but it makes also use of the other basic rule of compatibility, namely, the rule of "complementarity matching". This complementarity matching becomes particularly operational with the sound definition of the acidic and basic components of the solvation parameter based on the third σ-moments of the screening charge distributions of the quantum mechanics-based COSMO-RS theory. The new definitions are made in a simple and straightforward manner, thus, preserving the strength and appeal of solubility parameter stemming from its simplicity. The new predictive method has been applied to a variety of solubility data for systems of pharmaceuticals and polymers. The results from quantum mechanics calculations are critically compared with the results from Abraham's acid/base descriptors. PMID:22327537

  11. Health plan report cards and insurance choice.

    PubMed

    Chernew, M; Scanlon, D P

    1998-01-01

    This paper examines the relationship between consumers' health plan choices and health plan performance ratings. We make use of an initiative at a large firm to collect, aggregate, and disseminate to employees plan performance ratings. We estimate several statistical models, including share equations--which allow for the presence of important unobserved plan attributes--and logit models. Although report card ratings appear to be related to enrollment choices, the relationship is not uniform. For some dimensions of performance, the results are consistent with the hypothesis that employees respond to the performance ratings. For other dimensions, the ratings seem less influential than other plan attributes that employees likely observed without the data release. PMID:9597014

  12. Making Healthy Choices Easier: Regulation versus Nudging.

    PubMed

    Hansen, Pelle Guldborg; Skov, Laurits Rohden; Skov, Katrine Lund

    2016-01-01

    In recent years, the nudge approach to behavior change has emerged from the behavioral sciences to challenge the traditional use of regulation in public health strategies to address modifiable individual-level behaviors related to the rise of noncommunicable diseases and their treatment. However, integration and testing of the nudge approach as part of more comprehensive public health strategies aimed at making healthy choices easier are being threatened by inadequate understandings of its scientific character, its relationship with regulation, and its ethical implications. This article reviews this character and its ethical implication with a special emphasis on the compatibility of nudging with traditional regulation, special domains of experience, and the need for a more nuanced approach to the ethical debate. The aim is to advance readers' understanding and give guidance to those who have considered working with or incorporating the nudge approach into programs or policies aimed at making healthful choices easier. PMID:26735430

  13. Facultative mate choice drives adaptive hybridization.

    PubMed

    Pfennig, Karin S

    2007-11-01

    Mating with another species (hybridization) is often maladaptive. Consequently, females typically avoid heterospecifics as mates. Contrary to these expectations, female spadefoot toads were more likely to choose heterospecific males when exposed to environmental conditions that favor hybridization. Indeed, those females with phenotypic characteristics for which hybridization is most favorable were most likely to switch from choosing conspecifics to heterospecifics. Moreover, environmentally dependent mate choice has evolved only in populations and species that risk engaging in, and can potentially benefit from, hybridization. Thus, when the benefits of mate choice vary, females may radically alter their mate selection in response to their own phenotype and their environment, even to the point of choosing males of other species. PMID:17991861

  14. Sustainable food consumption. Product choice or curtailment?

    PubMed

    Verain, Muriel C D; Dagevos, Hans; Antonides, Gerrit

    2015-08-01

    Food consumption is an important factor in shaping the sustainability of our food supply. The present paper empirically explores different types of sustainable food behaviors. A distinction between sustainable product choices and curtailment behavior has been investigated empirically and predictors of the two types of behavior have been identified. Respondents were classified into four segments based on their sustainable food behaviors: unsustainers, curtailers, product-oriented consumers, and sustainers. Significant differences between the segments were found with regard to food choice motives, personal and social norms, food involvement, subjective knowledge on sustainable food, ability to judge how sustainably a product has been produced and socio-demographics. It is concluded that distinguishing between behavioral strategies toward sustainable food consumption is important as consumer segments can be identified that differ both in their level of sustainable food consumption and in the type of behavior they employ. PMID:25913683

  15. Adaptive gain control during human perceptual choice

    PubMed Central

    Cheadle, Samuel; Wyart, Valentin; Tsetsos, Konstantinos; Myers, Nicholas; de Gardelle, Vincent; Castañón, Santiago Herce; Summerfield, Christopher

    2015-01-01

    Neural systems adapt to background levels of stimulation. Adaptive gain control has been extensively studied in sensory systems, but overlooked in decision-theoretic models. Here, we describe evidence for adaptive gain control during the serial integration of decision-relevant information. Human observers judged the average information provided by a rapid stream of visual events (samples). The impact that each sample wielded over choices depended on its consistency with the previous sample, with more consistent or expected samples wielding the greatest influence over choice. This bias was also visible in the encoding of decision information in pupillometric signals, and in cortical responses measured with functional neuroimaging. These data can be accounted for with a new serial sampling model in which the gain of information processing adapts rapidly to reflect the average of the available evidence. PMID:24656259

  16. Modified mandated choice for organ procurement.

    PubMed

    Chouhan, P; Draper, H

    2003-06-01

    Presumed consent to organ donation looks increasingly unlikely to be a palatable option for increasing organ procurement in the UK following the publication of the report into events at Alder Hey and elsewhere. Yet, given that the alternative to increasing the number of cadaveric organs available is either to accept a greater number of live donations, or accept that people will continue to die for the want of an organ, public policy makers remain obliged to consider other means of increasing the procurement rate. In this paper, we meet the main objections to mandated choice (namely that it undermines autonomy and that mandated donation is preferable). We have modified the traditional approach to mandated choice to take into account the force of the objection that mandated donation is preferable, by accepting that people can and do make bad decisions about organ donation and proposing that all accompanying public education and information about cadaveric donation should be directed in favour of donation. PMID:12796435

  17. Nuclear matter within the continuous choice

    SciTech Connect

    Baldo, M.; Bombaci, I.; Ferreira, L.S.; Giansiracusa, G.; Lombardo, U. Dipartimento di Fisica, Universita di Catania, Corso Italia 57, 95129 Catania, Italy)

    1991-06-01

    The saturation curve of symmetric nuclear matter is calculated at the Brueckner-Hartree-Fock level of approximation within the continuous choice for the single-particle potential. The realistic local Argonne {ital v}{sub 14} potential is used and the results are compared with similar calculations presented in the literature. The binding energies per nucleon around saturation agree closely with previous results obtained with separable versions of the same potential as well as of the Paris potential.

  18. INJECTION CHOICE FOR SPALLATION NEUTRON SOURCE RING.

    SciTech Connect

    WEI,J.; BEEBE-WANG,J.; BLASKIEWICZ,M.; BRODOWSKI,J.; FEDOTOV,A.; GARDNER,C.; LEE,Y.Y.; RAPARIA,D.; DANILOV,V.; HOLMES,J.; PRIOR,C.; REES,G.; MACHIDA,S.

    2001-06-18

    Injection is key in the low-loss design of high-intensity proton facilities like the Spallation Neutron Source (SNS). During the design of both the accumulator and the rapid-cycling-synchrotron version of the SNS, extensive comparison has been made to select injection scenarios that satisfy SNS's low-loss design criteria. This paper presents issues and considerations pertaining to the final choice of the SNS injection systems.

  19. Rats exhibit reference-dependent choice behavior.

    PubMed

    Bhatti, Mehwish; Jang, Hyeran; Kralik, Jerald D; Jeong, Jaeseung

    2014-07-01

    Human preferences depend on whether a chosen outcome appears to be a loss or a gain compared with what had been expected, i.e., in comparison to a reference point. Because reference dependence has such a strong influence on human decision-making, it is important to uncover its origins, which will in turn help delineate the underlying mechanisms. It remains unknown whether rats use reference points in decision-making, and yet, the study of rats could help address the question of whether reference dependence is evolutionarily conserved among mammals and could provide a nonhuman animal model to investigate the neural mechanisms underlying this important cognitive process. The aim of the current study was to determine whether rats show reference-dependent choice behavior. We developed a novel paradigm by modifying the "T" maze by installing "pockets" to the left and right of the "T" stem that held reward pellets so rats would potentially develop reference values for each option prior to choice. We found that the rats were indeed sensitive to the way alternatives were presented. That is, they exhibited reference-dependent choice behavior by avoiding the choice option framed as a loss (e.g., having four reward pellets in the pocket, but receiving only one), at least under conditions with certain outcomes and clear differences between the reference and outcome quantities. Despite the small number of rats in this study, this species-level capacity suggests that reference dependence in general and loss aversion in particular may be conserved traits that evolved at or before the emergence of mammals. PMID:24657593

  20. Arbitration between controlled and impulsive choices

    PubMed Central

    Economides, M.; Guitart-Masip, M.; Kurth-Nelson, Z.; Dolan, R.J.

    2015-01-01

    The impulse to act for immediate reward often conflicts with more deliberate evaluations that support long-term benefit. The neural architecture that negotiates this conflict remains unclear. One account proposes a single neural circuit that evaluates both immediate and delayed outcomes, while another outlines separate impulsive and patient systems that compete for behavioral control. Here we designed a task in which a complex payout structure divorces the immediate value of acting from the overall long-term value, within the same outcome modality. Using model-based fMRI in humans, we demonstrate separate neural representations of immediate and long-term values, with the former tracked in the anterior caudate (AC) and the latter in the ventromedial prefrontal cortex (vmPFC). Crucially, when subjects' choices were compatible with long-run consequences, value signals in AC were down-weighted and those in vmPFC were enhanced, while the opposite occurred when choice was impulsive. Thus, our data implicate a trade-off in value representation between AC and vmPFC as underlying controlled versus impulsive choice. PMID:25573670

  1. Offering informed choice about breast screening.

    PubMed

    Forbes, Lindsay J L; Ramirez, Amanda-Jane

    2014-12-01

    Over the last few years, there has been growing international concern about the risk of overdiagnosis in breast screening and about how to communicate this to women. There has also been an increasing policy drive to provide people with information to enable them to make an informed choice about screening. In response to this, a novel approach to developing the information about cancer screening has been adopted in England. This approach has integrated the perspectives of people eligible for screening, and experts in public engagement, informed choice, and communicating risk, as well as experts in screening. New information based on this approach has been provided to women invited for breast screening from September 2013. The new information explicitly sets out the choice to be made, and provides much more detail than previous information about overdiagnosis, the balance of benefits and harms, and the scientific uncertainties. The novel approach has also been adopted to develop new information for the bowel and cervical screening programmes in England, and could provide a model for communicating about cancer screening in other countries. PMID:25312639

  2. Honey bees selectively avoid difficult choices

    PubMed Central

    Perry, Clint J.; Barron, Andrew B.

    2013-01-01

    Human decision-making strategies are strongly influenced by an awareness of certainty or uncertainty (a form of metacognition) to increase the chances of making a right choice. Humans seek more information and defer choosing when they realize they have insufficient information to make an accurate decision, but whether animals are aware of uncertainty is currently highly contentious. To explore this issue, we examined how honey bees (Apis mellifera) responded to a visual discrimination task that varied in difficulty between trials. Free-flying bees were rewarded for a correct choice, punished for an incorrect choice, or could avoid choosing by exiting the trial (opting out). Bees opted out more often on difficult trials, and opting out improved their proportion of successful trials. Bees could also transfer the concept of opting out to a novel task. Our data show that bees selectively avoid difficult tasks they lack the information to solve. This finding has been considered as evidence that nonhuman animals can assess the certainty of a predicted outcome, and bees’ performance was comparable to that of primates in a similar paradigm. We discuss whether these behavioral results prove bees react to uncertainty or whether associative mechanisms can explain such findings. To better frame metacognition as an issue for neurobiological investigation, we propose a neurobiological hypothesis of uncertainty monitoring based on the known circuitry of the honey bee brain. PMID:24191024

  3. Impact of communication on consumers' food choices.

    PubMed

    Verbeke, Wim

    2008-08-01

    Consumers' food choices and dietary behaviour can be markedly affected by communication and information. Whether the provided information is processed by the receiver, and thus becomes likely to be effective, depends on numerous factors. The role of selected determinants such as uncertainty, knowledge, involvement, health-related motives and trust, as well as message content variables, are discussed in the present paper based on previous empirical studies. The different studies indicate that: uncertainty about meat quality and safety does not automatically result in more active information search; subjective knowledge about fish is a better predictor of fish consumption than objective knowledge; high subjective knowledge about functional foods as a result of a low trusted information source such as mass media advertising leads to a lower probability of adopting these foods in the diet. Also, evidence of the stronger impact of negative news as compared with messages promoting positive outcomes of food choices is discussed. Finally, three audience-segmentation studies based on consumers' involvement with fresh meat, individuals' health-related-motive orientations and their use of and trust in fish information sources are presented. A clear message from these studies is that communication and information provision strategies targeted to a specific audience's needs, interests or motives stand a higher likelihood of being attended to and processed by the receiving audience, and therefore also stand a higher chance of yielding their envisaged impact in terms of food choice and dietary behaviour. PMID:18498672

  4. Air Cargo Transportation Route Choice Analysis

    NASA Technical Reports Server (NTRS)

    Obashi, Hiroshi; Kim, Tae-Seung; Oum, Tae Hoon

    2003-01-01

    Using a unique feature of air cargo transshipment data in the Northeast Asian region, this paper identifies the critical factors that determine the transshipment route choice. Taking advantage of the variations in the transport characteristics in each origin-destination airports pair, the paper uses a discrete choice model to describe the transshipping route choice decision made by an agent (i.e., freight forwarder, consolidator, and large shipper). The analysis incorporates two major factors, monetary cost (such as line-haul cost and landing fee) and time cost (i.e., aircraft turnaround time, including loading and unloading time, custom clearance time, and expected scheduled delay), along with other controls. The estimation method considers the presence of unobserved attributes, and corrects for resulting endogeneity by use of appropriate instrumental variables. Estimation results find that transshipment volumes are more sensitive to time cost, and that the reduction in aircraft turnaround time by 1 hour would be worth the increase in airport charges by more than $1000. Simulation exercises measures the impacts of alternative policy scenarios for a Korean airport, which has recently declared their intention to be a future regional hub in the Northeast Asian region. The results suggest that reducing aircraft turnaround time at the airport be an effective strategy, rather than subsidizing to reduce airport charges.

  5. The Role of Angularity in Route Choice

    NASA Astrophysics Data System (ADS)

    Turner, Alasdair

    The paths of 2425 individual motorcycle trips made in London were analyzed in order to uncover the route choice decisions made by drivers. The paths were derived from global positioning system (GPS) data collected by a courier company for each of their drivers, using algorithms developed for the purpose of this paper. Motorcycle couriers were chosen due to the fact that they both know streets very well and that they do not rely on the GPS to guide their navigation. Each trace was mapped to the underlying road network, and two competing hypotheses for route choice decisions were compared: (a) that riders attempt to minimize the Manhattan distance between locations and (b) that they attempt to minimize the angular distance. In each case, the distance actually traveled was compared to the minimum possible either block or angular distance through the road network. It is usually believed that drivers who know streets well will navigate trips that reduce Manhattan distance; however, here it is shown that angularity appears to play an important role in route choice. 63% of trips made took the minimum possible angular distance between origin and destination, while 51% of trips followed the minimum possible block distance. This implies that impact of turns on cognitive distance plays an important role in decision making, even when a driver has good knowledge of the spatial network.

  6. Model for understanding consumer textural food choice

    PubMed Central

    Jeltema, Melissa; Beckley, Jacqueline; Vahalik, Jennifer

    2015-01-01

    The current paradigm for developing products that will match the marketing messaging is flawed because the drivers of product choice and satisfaction based on texture are misunderstood. Qualitative research across 10 years has led to the thesis explored in this research that individuals have a preferred way to manipulate food in their mouths (i.e., mouth behavior) and that this behavior is a major driver of food choice, satisfaction, and the desire to repurchase. Texture, which is currently thought to be a major driver of product choice, is a secondary factor, and is important only in that it supports the primary driver—mouth behavior. A model for mouth behavior is proposed and the qualitative research supporting the identification of different mouth behaviors is presented. The development of a trademarked typing tool for characterizing mouth behavior is described along with quantitative substantiation of the tool's ability to group individuals by mouth behavior. The use of these four groups to understand textural preferences and the implications for a variety of areas including product design and weight management are explored. PMID:25987995

  7. Sensitivity, changeover responses, and choice in transition.

    PubMed

    Jiménez, Angel A; Aparicio, Carlos F

    2009-09-01

    Studies of choice in steady state have shown that sensitivity to reinforcement increases with increasing fixed-ratio changeover (FR CO) requirements. We assessed the generality of this finding with choice in transition. Food deliveries were programmed according to concurrent variable-interval (VI) schedules. Seven different VI pairs arranged ratios of food deliveries (left/right) of 27:1, 9:1, 3:1, 1:1, 1:3, 1:9, and 1:27 at a constant overall rate across components. Within sessions, all seven ratios were presented in random order. Each component lasted for 10 food deliveries; components were separated by 60-s blackouts. A changeover lever required 1, 2, 4, 8, 16, 32, and 64 responses to alternate between two main levers. Redeterminations to all FR COs, but 64 responses, were obtained in descending order. Choice adjusted rapidly to rapid changes in the reinforcer ratio, tracking the lever associated with the highest probability of reinforcer. Sensitivity to reinforcement increased with increasing FR CO, replicating the negatively accelerated function found in our earlier study. With successive reinforcers in components, however, sensitivity reached asymptote values sooner with the largest (8, 16, and 32 responses), than with the smallest (1, 2, and 4 responses), FR CO requirements. PMID:19615608

  8. Model for understanding consumer textural food choice.

    PubMed

    Jeltema, Melissa; Beckley, Jacqueline; Vahalik, Jennifer

    2015-05-01

    The current paradigm for developing products that will match the marketing messaging is flawed because the drivers of product choice and satisfaction based on texture are misunderstood. Qualitative research across 10 years has led to the thesis explored in this research that individuals have a preferred way to manipulate food in their mouths (i.e., mouth behavior) and that this behavior is a major driver of food choice, satisfaction, and the desire to repurchase. Texture, which is currently thought to be a major driver of product choice, is a secondary factor, and is important only in that it supports the primary driver-mouth behavior. A model for mouth behavior is proposed and the qualitative research supporting the identification of different mouth behaviors is presented. The development of a trademarked typing tool for characterizing mouth behavior is described along with quantitative substantiation of the tool's ability to group individuals by mouth behavior. The use of these four groups to understand textural preferences and the implications for a variety of areas including product design and weight management are explored. PMID:25987995

  9. Putting Health Back Into Health Insurance Choice.

    PubMed

    Atanasov, Pavel; Baker, Tom

    2014-08-01

    What are the barriers to voluntary take-up of high-deductible plans? We address this question using a large-scale employer survey conducted after an open-enrollment period in which a new high-deductible plan was first introduced. Only 3% of the employees chose this plan, despite the respondents' recognition of its financial advantages. Employees who believed that the high-deductible plan provided access to top physicians in the area were three times more likely to choose it than employees who did not share this belief. A framed field experiment using a similar choice menu showed that displaying additional financial information did not increase high-deductible plan take-up. However, when plans were presented as identical except for the deductible, respondents were highly likely to choose the high-deductible plan, especially in a two-way choice. These results suggest that informing plan choosers about high-deductible plans' health access provisions may affect choice more strongly than focusing on their financial advantages. PMID:24811934

  10. Russian consumers' motives for food choice.

    PubMed

    Honkanen, Pirjo; Frewer, Lynn

    2009-04-01

    Knowledge about food choice motives which have potential to influence consumer consumption decisions is important when designing food and health policies, as well as marketing strategies. Russian consumers' food choice motives were studied in a survey (1081 respondents across four cities), with the purpose of identifying consumer segments based on these motives. These segments were then profiled using consumption, attitudinal and demographic variables. Face-to-face interviews were used to sample the data, which were analysed with two-step cluster analysis (SPSS). Three clusters emerged, representing 21.5%, 45.8% and 32.7% of the sample. The clusters were similar in terms of the order of motivations, but differed in motivational level. Sensory factors and availability were the most important motives for food choice in all three clusters, followed by price. This may reflect the turbulence which Russia has recently experienced politically and economically. Cluster profiles differed in relation to socio-demographic factors, consumption patterns and attitudes towards health and healthy food. PMID:19073227

  11. The downside of choice: Having a choice benefits enjoyment, but at a cost to efficiency and time in visual search.

    PubMed

    Kunar, Melina A; Ariyabandu, Surani; Jami, Zaffran

    2016-04-01

    The efficiency of how people search for an item in visual search has, traditionally, been thought to depend on bottom-up or top-down guidance cues. However, recent research has shown that the rate at which people visually search through a display is also affected by cognitive strategies. In this study, we investigated the role of choice in visual search, by asking whether giving people a choice alters both preference for a cognitively neutral task and search behavior. Two visual search conditions were examined: one in which participants were given a choice of visual search task (the choice condition), and one in which participants did not have a choice (the no-choice condition). The results showed that the participants in the choice condition rated the task as both more enjoyable and likeable than did the participants in the no-choice condition. However, despite their preferences, actual search performance was slower and less efficient in the choice condition than in the no-choice condition (Exp. 1). Experiment 2 showed that the difference in search performance between the choice and no-choice conditions disappeared when central executive processes became occupied with a task-switching task. These data concur with a choice-impaired hypothesis of search, in which having a choice leads to more motivated, active search involving executive processes. PMID:26892010

  12. Degradation Parameters from Pulse-Chase Experiments

    PubMed Central

    Sin, Celine; Chiarugi, Davide; Valleriani, Angelo

    2016-01-01

    Pulse-chase experiments are often used to study the degradation of macromolecules such as proteins or mRNA. Considerations for the choice of pulse length include the toxicity of the pulse to the cell and maximization of labeling. In the general case of non-exponential decay, varying the length of the pulse results in decay patterns that look different. Analysis of these patterns without consideration to pulse length would yield incorrect degradation parameters. Here we propose a method that constructively includes pulse length in the analysis of decay patterns and extracts the parameters of the underlying degradation process. We also show how to extract decay parameters reliably from measurements taken during the pulse phase. PMID:27182698

  13. Determinants of journal choice among Nigerian medics

    PubMed Central

    Olusegun, Nwhator Solomon; Olayinka, Agbaje Maarufah; Modupe, Soroye; Ikenna, Isiekwe Gerald

    2015-01-01

    Introduction Despite the well-known maxim "publish or perish" among academicians, productivity remains low in Nigeria. There are barriers to academic writing which must be identified and addressed. Even after addressing those barriers, authors are faced with another dilemma-where to publish. It was the concern of the authors to evaluate perceived barriers to academic writing and the determinants of journal choice among Nigerian academics. They also attempted to evaluate the determinants of journal choice and perceived barriers to academic writing among Nigerian academicians. Respondents were academicians used in the context of this study to mean anyone involved in academic writing. Such persons must have written and published at least one paper in a peer-reviewed journal in the preceding year to be included in the survey. An online-based self-administered questionnaire. Methods An online structured and self-administered questionnaire-based cross sectional survey of Nigerian medical academicians was conducted over a period of one year using a Google-powered questionnaire. The questionnaire assessed the determinants of journal choice, perceived barriers to publications, number of publications in the preceding year as a measure of academic productivity and the highest publication fee authors were willing to pay. Results Of the over 500 email request sent, a total of 200 academicians responded (response rate of 40%). The male and female distribution was 120 and 80 respectively. The highest number of respondents were lecturer 1 and senior lecturers (or junior faculty) (69.5%) however the senior faculty had the higher number of publications in the preceding year. Indexing (35.5%) was the most important determinant of journal choice whilst ease of submission (2.1%) was the least. Unfriendly environment (46%) was the most perceived barrier to publication. Though, majority (88.5%) of the respondents were willing to pay up $300 as publication fees, twice as many junior

  14. Modelling the evolution of female choice strategies under inbreeding conditions.

    PubMed

    Reinhold, Klaus

    2002-11-01

    Recently, many mate choice studies have discussed the role of genetic compatibility and inbreeding for the evolution of mate choice. With population genetic simulations I compared the potential advantage of three different female choice strategies under inbreeding conditions. Females were assumed to benefit indirectly via a preference for (i) complementary males, (ii) males with few detrimental mutations, and (iii) non-inbred males. Probably related to the reduced inbreeding depression in offspring of choosy females, the choice-allele increased for all three strategies. However, the advantage of the strategies differed widely. Choice of males with fewer mutations provided a comparatively large advantage, choice of complementary males led to a reasonable advantage, and choice of non-inbred males only resulted in a minor advantage of female choice. My results show that complementary mate choice can be almost as beneficial as conventional good-genes choice of mates with lower genetic load. Compared to the two other mate choice strategies, choice of non-inbred males is less likely to contribute to the evolution of costly mate choice. The results of a recent study showing that female sticklebacks prefer males with a larger number of MHC-loci is thus unlikely to be related to an indirect benefit of choosing non-inbred males. PMID:12555777

  15. A cumulative decision model for three-alternative choice in concurrent chains.

    PubMed

    Grace, Randolph C; McLean, Anthony P

    2016-07-01

    Traditional models for choice in the concurrent-chains procedure have assumed that terminal-link stimuli acquire value as conditioned reinforcers, and that 2-alternative choice provides a measure of relative value according to the matching law. By contrast, the cumulative decision model (CDM; Christensen & Grace, 2010) explains choice as the aggregate effect of comparing delays to a criterion on initial-link responding, not conditioned reinforcement. Here we test whether the CDM can account for choice in 3-alternative concurrent-chains (3ACC) and compare it with the hyperbolic value-added model (HVA; Mazur, 2001), which assumes that choice depends on the increase in conditioned reinforcement value signaled by terminal-link stimuli and has been successful in previous 3ACC research (Mazur, 2000). In Experiment 1, 4 pigeons responded in 3ACC in which the terminal links were fixed-interval schedules, and parameter estimates from fits of CDM and HVA were used to calculate predictions for conditions with variable-interval terminal links. The predictions of CDM were more accurate than those of HVA. In Experiment 2, 7 pigeons responded in 3ACC in which the terminal links were fixed-interval schedules. Although both models described the data well, residuals from HVA fits showed a systematic pattern predicted by CDM, characterized by a third-order polynomial with a negative cubic coefficient. Finally, we conducted a residual meta-analysis (Sutton, Grace, McLean, & Baum, 2008) of data from prior 3ACC studies. HVA residuals showed the same negative cubic pattern as in Experiment 2, whereas no systematic pattern was found in the CDM residuals. Overall, results support the CDM and suggest that the same principles which describe binary choice in concurrent chains generalize without modification to 3-alternative choice. (PsycINFO Database Record PMID:27379716

  16. Optimized Parameters for a Mercury Jet Target

    SciTech Connect

    Ding, X.; Kirk, H.

    2010-12-01

    A study of target parameters for a high-power, liquid mercury jet target system for a neutrino factory or muon collider is presented. Using the MARS code, we simulate particle production initiated by incoming protons with kinetic energies between 2 and 100 GeV. For each proton beam energy, we maximize production by varying the geometric parameters of the target: the mercury jet radius, the incoming proton beam angle, and the crossing angle between the mercury jet and the proton beam. The number of muons surviving through an ionization cooling channel is determined as a function of the proton beam energy. We optimize the mercury jet target parameters: the mercury jet radius, the incoming proton beam angle and the crossing angle between the mercury jet and the proton beam for each proton beam energy. The optimized target radius varies from about 0.4 cm to 0.6 cm as the proton beam energy increases. The optimized beam angle varies from 75 mrad to 120 mrad. The optimized crossing angle is near 20 mrad for energies above 5 GeV. These values differ from earlier choices of 67 mrad for the beam angle and 33 mrad for the crossing angle. These new choices for the beam parameters increase the meson production by about 20% compared to the earlier parameters. Our study demonstrates that the maximum meson production efficiency per unit proton beam power occurs when the proton kinetic energy is in the range of 5-15 GeV. Finally, the dependence on energy of the number of muons at the end of the cooling channel is nearly identical to the dependence on energy of the meson production 50 m from the target. This demonstrates that the target parameters can be optimized without the additional step of running the distribution through a code such as ICOOL that simulates the bunching, phase rotation, and cooling.

  17. A Python-based IRAF Task Parameter Editor

    NASA Astrophysics Data System (ADS)

    de La Peña, M. D.

    As part of the development of a new Python-based CL for IRAF tasks by the Science Software Group at STScI, we have developed a GUI-based parameter editor for IRAF tasks using Tkinter. This new parameter editor is intended to provide the equivalent functionality of the IRAF EPAR task, but to make parameter editing easier by using appropriate user interface elements, such as menu choice lists, action buttons, and file browsers. This paper describes the design and functionality of the parameter editor as well as planned enhancements.

  18. The role of word choice and criterion on intentional memory.

    PubMed

    Toyota, Hiroshi

    2015-02-01

    The relationship between the criterion for choosing and the self-choice effects (greater recall in a self-choice compared to a forced-choice condition) on intentional memory was examined. Thirty-three female nursing school volunteers were administered 24 word pairs in a 2 × 2 design to assess the influence of motivation upon free recall. When word pairs were presented to participants, they were asked to choose a word to-be-remembered, either in a self-choice condition or a forced-choice condition. Words chosen by the participants were recalled more often than those chosen by the experimenter (forced choice). Thus, the self-choice effect was greater for words chosen with a self-reference criterion compared to a metamemory criterion, supporting the integration hypothesis as the origin of the self-choice effect. PMID:25621524

  19. Research on bounded rationality of fuzzy choice functions.

    PubMed

    Wu, Xinlin; Zhao, Yong

    2014-01-01

    The rationality of a fuzzy choice function is a hot research topic in the study of fuzzy choice functions. In this paper, two common fuzzy sets are studied and analyzed in the framework of the Banerjee choice function. The complete rationality and bounded rationality of fuzzy choice functions are defined based on the two fuzzy sets. An assumption is presented to study the fuzzy choice function, and especially the fuzzy choice function with bounded rationality is studied combined with some rationality conditions. Results show that the fuzzy choice function with bounded rationality also satisfies some important rationality conditions, but not vice versa. The research gives supplements to the investigation in the framework of the Banerjee choice function. PMID:24782677

  20. Implementing a Children's Choice Award at Your School

    ERIC Educational Resources Information Center

    Obert, Beverly J.

    2005-01-01

    Children's choice awards are intended to encourage children, primary age through teens, to read quality literature for enjoyment. The reasons for joining a children's choice program before deciding to participate are presented.

  1. Making Rhetorical Choices: The Parallel between Extemporaneous and Presidential Speaking.

    ERIC Educational Resources Information Center

    Aden, Roger C.

    1992-01-01

    Analyses the rhetorical choices of President George Bush in speeches announcing military action in Panama and Iraq. Demonstrates how understanding those choices can educate students participating in extemporaneous speaking. (SR)

  2. Multi-choice multi-objective mathematical programming model for integrated production planning: a case study

    NASA Astrophysics Data System (ADS)

    Biswal, M. P.; Acharya, S.

    2013-09-01

    This article develops a multi-choice multi-objective linear programming model in order to solve an integrated production planning problem of a steel plant. The aim of the integrated production planning problem is to integrate the planning sub-functions into a single planning operation. The sub-functions are formulated by considering the capacity of different units of the plant, cost of raw materials from various territories, demands of customers in different geographical locations, time constraint for delivery the products, production cost and production rate at different stages of production process. Departure cost is also considered in the formulation of mathematical programming model. Some of the parameters are decided from a set of possible choices, therefore such parameters are considered as multi-choice type. Multi-choice mathematical programming problem cannot be solved directly. Therefore an equivalent multi-objective mathematical programming model is established in order to find the optimal solution of the problem. Computation of the mathematical programming model is performed with the practical production data of a plant to study the methodology.

  3. Choice from non-choice: Predicting consumer preferences from BOLD signals obtained during passive viewing

    PubMed Central

    Levy, Ifat; Lazzaro, Stephanie C.; Rutledge, Robb B.; Glimcher, Paul W.

    2011-01-01

    Decision-making is often viewed as a two-stage process, where subjective values are first assigned to each option and then the option of the highest value is selected. Converging evidence suggests that these subjective values are represented in the striatum and medial prefrontal cortex (MPFC). A separate line of evidence suggests that activation in the same areas represents the values of rewards even when choice is not required, as in classical conditioning tasks. However, it is unclear whether the same neural mechanism is engaged in both cases. To address this question we measured brain activation with fMRI while human subjects passively viewed individual consumer goods. We then sampled activation from predefined regions of interest and used it to predict subsequent choices between the same items made outside of the scanner. Our results show that activation in the striatum and MPFC in the absence of choice predicts subsequent choices, suggesting that these brain areas represent value in a similar manner whether or not choice is required. PMID:21209196

  4. Freedom and School Choice in American Education. Education Policy

    ERIC Educational Resources Information Center

    Forster, Greg, Ed.; Thompson, C. Bradley, Ed.

    2011-01-01

    Leading intellectual figures in the school reform movement, all of them favoring approaches centered around the value of competition and choice, outline different visions for the goal of choice-oriented educational reform and the best means for achieving it. This volume takes the reader inside the movement to empower parents with choice, airing…

  5. Factors and Influences on High School Student's Career Choices.

    ERIC Educational Resources Information Center

    Dick, Thomas P.; Rallis, Sharon F.

    1991-01-01

    A survey (n=2213) of high school seniors from nine Rhode Island schools studied their academic and career choices related to science and engineering and the perceived influences on those choices. Gender differences are discussed for the influences of parents, pay, interest, and teachers, with the latter potentially influencing career choices of…

  6. Choice Strategies in Multiple-Cue Probability Learning

    ERIC Educational Resources Information Center

    White, Chris M.; Koehler, Derek J.

    2007-01-01

    Choice strategies for selecting among outcomes in multiple-cue probability learning were investigated using a simulated medical diagnosis task. Expected choice probabilities (the proportion of times each outcome was selected given each cue pattern) under alternative choice strategies were constructed from corresponding observed judged…

  7. Public Choice, Market Failure, and Government Failure in Principles Textbooks

    ERIC Educational Resources Information Center

    Fike, Rosemarie; Gwartney, James

    2015-01-01

    Public choice uses the tools of economics to analyze how the political process allocates resources and impacts economic activity. In this study, the authors examine twenty-three principles texts regarding coverage of public choice, market failure, and government failure. Approximately half the texts provide coverage of public choice and recognize…

  8. Female Adolescents' Educational Choices about Reproductive Health Modules

    ERIC Educational Resources Information Center

    Gold, Melanie A.; Chiappetta, Laurel; Young, Amanda J.; Zuckoff, Allan; DiClemente, Carlo C.

    2008-01-01

    Purpose: To assess girls' reproductive educational choices, satisfaction with choice, and relationship between demographics, module choice, and satisfaction. Methods: We recruited 286 girls, aged 13 to 21 years, from a hospital-based adolescent clinic, from advertisements, and by word of mouth. At enrollment, participants completed a 60-minute…

  9. Auditory Comprehension: Is Multiple Choice Really Good Enough?

    ERIC Educational Resources Information Center

    Breese, Elisabeth L.; Hillis, Argye E.

    2004-01-01

    Auditory comprehension is commonly measured with multiple choice tasks. The sensitivity of these tasks in identifying deficits, however, is limited by credit given for correct guesses by forced choice. In this study, we compare performance on the multiple choice task to an alternative word/picture verification task, in 122 subjects with acute left…

  10. Celebrating Children's Choices: 25 Years of Children's Favorite Books.

    ERIC Educational Resources Information Center

    Post, Arden DeVries

    This book provides the background and development of the Children's Choices project and highlights many of the best known and most popular books that have appeared on the Children's Choices list over the past 25 years. Each book selection features a picture of the book jacket, an annotation from the Choices list, a list of classroom applications,…

  11. The Stay/Switch Model of Concurrent Choice

    ERIC Educational Resources Information Center

    MacDonall, James S.

    2009-01-01

    This experiment compared descriptions of concurrent choice by the stay/switch model, which says choice is a function of the reinforcers obtained for staying at and for switching from each alternative, and the generalized matching law, which says choice is a function of the total reinforcers obtained at each alternative. For the stay/switch model…

  12. The Social and Ideological Construction of "Free-Choice Reading."

    ERIC Educational Resources Information Center

    Lewis, Cynthia

    Students' book choices and discussions during independent reading were studied in a combined fifth/sixth grade classroom. The meanings students and the teacher gave to the practice of independent, "free-choice" reading were studied, and the influences that shaped students' choices of books were explored. Independent reading is actually social in…

  13. Free School Choice and the Educational Achievement Gap

    ERIC Educational Resources Information Center

    van Welie, Liesbeth; Hartog, Joop; Cornelisz, Ilja

    2013-01-01

    In the Netherlands, school choice is free and all schools are equally funded by the government. We measured distance from home to school as a proxy for the selectivity of choice and used characteristics of the nearest school to explain the choice of a school other than the nearest school. Almost 89% of all pupils in the 4 largest cities do not…

  14. Study of the Voluntary Public School Choice Program. Final Report

    ERIC Educational Resources Information Center

    Yin, Robert K.; Ahonen, Pirkko S.

    2008-01-01

    The Voluntary Public School Choice (VPSC) Program supports the emergence and growth of choice initiatives across the country, by assisting states and local school districts in developing innovative strategies to expand public school choice options for students. This report contains the final assessment of the first five years of the VPSC Program…

  15. 14 CFR 1260.59 - Choice of law.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Choice of law. 1260.59 Section 1260.59... Special Conditions § 1260.59 Choice of law. Choice of Law October 2000 The rights and obligations of the parties to the grant (or cooperative agreement) shall be ascertainable by recourse to the laws of...

  16. 48 CFR 352.233-70 - Choice of law (overseas).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Choice of law (overseas... Choice of law (overseas). As prescribed in 333.215-70(a), the Contracting Officer shall insert the following clause: Choice of Law (Overseas) (January 2010) This contract shall be construed in...

  17. 14 CFR 1260.59 - Choice of law.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Choice of law. 1260.59 Section 1260.59... Special Conditions § 1260.59 Choice of law. Choice of Law October 2000 The rights and obligations of the parties to the grant (or cooperative agreement) shall be ascertainable by recourse to the laws of...

  18. 48 CFR 252.233-7001 - Choice of law (overseas).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Choice of law (overseas... of Provisions And Clauses 252.233-7001 Choice of law (overseas). As prescribed in 233.215-70, use the following clause: Choice of Law (Overseas) (JUN 1997) This contract shall be construed and interpreted...

  19. Memory Attributions for Choices: How Beliefs Shape Our Memories

    ERIC Educational Resources Information Center

    Henkel, Linda A.; Mather, Mara

    2007-01-01

    When remembering past choices, people tend to attribute positive features to chosen options and negative features to rejected options. The present experiments reveal the important role beliefs play in memory reconstruction of choices. In Experiment 1, participants who misremembered which option they chose favored their believed choice in their…

  20. The Effect of Choice Format on Internal Consistency.

    ERIC Educational Resources Information Center

    Weber, Margaret B.

    The effects of different choice formats on the reliability of teacher-made tests were examined for high and low achievers. The first study examined the effect of 3 and 5 choice items on the reliability of dichotomously scored teacher-made tests. The second study examined the effect of 3 and 4 choice items on the reliability of similarly designed…