Sample records for jacobian matrix norm

  1. Inversion Of Jacobian Matrix For Robot Manipulators

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Bejczy, Antal K.

    1989-01-01

    Report discusses inversion of Jacobian matrix for class of six-degree-of-freedom arms with spherical wrist, i.e., with last three joints intersecting. Shows by taking advantage of simple geometry of such arms, closed-form solution of Q=J-1X, which represents linear transformation from task space to joint space, obtained efficiently. Presents solutions for PUMA arm, JPL/Stanford arm, and six-revolute-joint coplanar arm along with all singular points. Main contribution of paper shows simple geometry of this type of arms exploited in performing inverse transformation without any need to compute Jacobian or its inverse explicitly. Implication of this computational efficiency advanced task-space control schemes for spherical-wrist arms implemented more efficiently.

  2. Weighted augmented Jacobian matrix with a variable coefficient method for kinematics mapping of space teleoperation based on human-robot motion similarity

    NASA Astrophysics Data System (ADS)

    Shi, Zhong; Huang, Xuexiang; Hu, Tianjian; Tan, Qian; Hou, Yuzhuo

    2016-10-01

    Space teleoperation is an important space technology, and human-robot motion similarity can improve the flexibility and intuition of space teleoperation. This paper aims to obtain an appropriate kinematics mapping method of coupled Cartesian-joint space for space teleoperation. First, the coupled Cartesian-joint similarity principles concerning kinematics differences are defined. Then, a novel weighted augmented Jacobian matrix with a variable coefficient (WAJM-VC) method for kinematics mapping is proposed. The Jacobian matrix is augmented to achieve a global similarity of human-robot motion. A clamping weighted least norm scheme is introduced to achieve local optimizations, and the operating ratio coefficient is variable to pursue similarity in the elbow joint. Similarity in Cartesian space and the property of joint constraint satisfaction is analysed to determine the damping factor and clamping velocity. Finally, a teleoperation system based on human motion capture is established, and the experimental results indicate that the proposed WAJM-VC method can improve the flexibility and intuition of space teleoperation to complete complex space tasks.

  3. Implementing a Matrix-free Analytical Jacobian to Handle Nonlinearities in Models of 3D Lithospheric Deformation

    NASA Astrophysics Data System (ADS)

    Kaus, B.; Popov, A.

    2015-12-01

    The analytical expression for the Jacobian is a key component to achieve fast and robust convergence of the nonlinear Newton-Raphson iterative solver. Accomplishing this task in practice often requires a significant algebraic effort. Therefore it is quite common to use a cheap alternative instead, for example by approximating the Jacobian with a finite difference estimation. Despite its simplicity it is a relatively fragile and unreliable technique that is sensitive to the scaling of the residual and unknowns, as well as to the perturbation parameter selection. Unfortunately no universal rule can be applied to provide both a robust scaling and a perturbation. The approach we use here is to derive the analytical Jacobian for the coupled set of momentum, mass, and energy conservation equations together with the elasto-visco-plastic rheology and a marker in cell/staggered finite difference method. The software project LaMEM (Lithosphere and Mantle Evolution Model) is primarily developed for the thermo-mechanically coupled modeling of the 3D lithospheric deformation. The code is based on a staggered grid finite difference discretization in space, and uses customized scalable solvers form PETSc library to efficiently run on the massively parallel machines (such as IBM Blue Gene/Q). Currently LaMEM relies on the Jacobian-Free Newton-Krylov (JFNK) nonlinear solver, which approximates the Jacobian-vector product using a simple finite difference formula. This approach never requires an assembled Jacobian matrix and uses only the residual computation routine. We use an approximate Jacobian (Picard) matrix to precondition the Krylov solver with the Galerkin geometric multigrid. Because of the inherent problems of the finite difference Jacobian estimation, this approach doesn't always result in stable convergence. In this work we present and discuss a matrix-free technique in which the Jacobian-vector product is replaced by analytically-derived expressions and compare results

  4. Parallel Computation of the Jacobian Matrix for Nonlinear Equation Solvers Using MATLAB

    NASA Technical Reports Server (NTRS)

    Rose, Geoffrey K.; Nguyen, Duc T.; Newman, Brett A.

    2017-01-01

    Demonstrating speedup for parallel code on a multicore shared memory PC can be challenging in MATLAB due to underlying parallel operations that are often opaque to the user. This can limit potential for improvement of serial code even for the so-called embarrassingly parallel applications. One such application is the computation of the Jacobian matrix inherent to most nonlinear equation solvers. Computation of this matrix represents the primary bottleneck in nonlinear solver speed such that commercial finite element (FE) and multi-body-dynamic (MBD) codes attempt to minimize computations. A timing study using MATLAB's Parallel Computing Toolbox was performed for numerical computation of the Jacobian. Several approaches for implementing parallel code were investigated while only the single program multiple data (spmd) method using composite objects provided positive results. Parallel code speedup is demonstrated but the goal of linear speedup through the addition of processors was not achieved due to PC architecture.

  5. Sensitivity analysis of Jacobian determinant used in treatment planning for lung cancer

    NASA Astrophysics Data System (ADS)

    Shao, Wei; Gerard, Sarah E.; Pan, Yue; Patton, Taylor J.; Reinhardt, Joseph M.; Durumeric, Oguz C.; Bayouth, John E.; Christensen, Gary E.

    2018-03-01

    Four-dimensional computed tomography (4DCT) is regularly used to visualize tumor motion in radiation therapy for lung cancer. These 4DCT images can be analyzed to estimate local ventilation by finding a dense correspondence map between the end inhalation and the end exhalation CT image volumes using deformable image registration. Lung regions with ventilation values above a threshold are labeled as regions of high pulmonary function and are avoided when possible in the radiation plan. This paper investigates a sensitivity analysis of the relative Jacobian error to small registration errors. We present a linear approximation of the relative Jacobian error. Next, we give a formula for the sensitivity of the relative Jacobian error with respect to the Jacobian of perturbation displacement field. Preliminary sensitivity analysis results are presented using 4DCT scans from 10 individuals. For each subject, we generated 6400 random smooth biologically plausible perturbation vector fields using a cubic B-spline model. We showed that the correlation between the Jacobian determinant and the Frobenius norm of the sensitivity matrix is close to -1, which implies that the relative Jacobian error in high-functional regions is less sensitive to noise. We also showed that small displacement errors on the average of 0.53 mm may lead to a 10% relative change in Jacobian determinant. We finally showed that the average relative Jacobian error and the sensitivity of the system for all subjects are positively correlated (close to +1), i.e. regions with high sensitivity has more error in Jacobian determinant on average.

  6. Reducing computational costs in large scale 3D EIT by using a sparse Jacobian matrix with block-wise CGLS reconstruction.

    PubMed

    Yang, C L; Wei, H Y; Adler, A; Soleimani, M

    2013-06-01

    Electrical impedance tomography (EIT) is a fast and cost-effective technique to provide a tomographic conductivity image of a subject from boundary current-voltage data. This paper proposes a time and memory efficient method for solving a large scale 3D EIT inverse problem using a parallel conjugate gradient (CG) algorithm. The 3D EIT system with a large number of measurement data can produce a large size of Jacobian matrix; this could cause difficulties in computer storage and the inversion process. One of challenges in 3D EIT is to decrease the reconstruction time and memory usage, at the same time retaining the image quality. Firstly, a sparse matrix reduction technique is proposed using thresholding to set very small values of the Jacobian matrix to zero. By adjusting the Jacobian matrix into a sparse format, the element with zeros would be eliminated, which results in a saving of memory requirement. Secondly, a block-wise CG method for parallel reconstruction has been developed. The proposed method has been tested using simulated data as well as experimental test samples. Sparse Jacobian with a block-wise CG enables the large scale EIT problem to be solved efficiently. Image quality measures are presented to quantify the effect of sparse matrix reduction in reconstruction results.

  7. pyJac: Analytical Jacobian generator for chemical kinetics

    NASA Astrophysics Data System (ADS)

    Niemeyer, Kyle E.; Curtis, Nicholas J.; Sung, Chih-Jen

    2017-06-01

    Accurate simulations of combustion phenomena require the use of detailed chemical kinetics in order to capture limit phenomena such as ignition and extinction as well as predict pollutant formation. However, the chemical kinetic models for hydrocarbon fuels of practical interest typically have large numbers of species and reactions and exhibit high levels of mathematical stiffness in the governing differential equations, particularly for larger fuel molecules. In order to integrate the stiff equations governing chemical kinetics, generally reactive-flow simulations rely on implicit algorithms that require frequent Jacobian matrix evaluations. Some in situ and a posteriori computational diagnostics methods also require accurate Jacobian matrices, including computational singular perturbation and chemical explosive mode analysis. Typically, finite differences numerically approximate these, but for larger chemical kinetic models this poses significant computational demands since the number of chemical source term evaluations scales with the square of species count. Furthermore, existing analytical Jacobian tools do not optimize evaluations or support emerging SIMD processors such as GPUs. Here we introduce pyJac, a Python-based open-source program that generates analytical Jacobian matrices for use in chemical kinetics modeling and analysis. In addition to producing the necessary customized source code for evaluating reaction rates (including all modern reaction rate formulations), the chemical source terms, and the Jacobian matrix, pyJac uses an optimized evaluation order to minimize computational and memory operations. As a demonstration, we first establish the correctness of the Jacobian matrices for kinetic models of hydrogen, methane, ethylene, and isopentanol oxidation (number of species ranging 13-360) by showing agreement within 0.001% of matrices obtained via automatic differentiation. We then demonstrate the performance achievable on CPUs and GPUs using py

  8. Off-diagonal Jacobian support for Nodal BCs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peterson, John W.; Andrs, David; Gaston, Derek R.

    In this brief note, we describe the implementation of o-diagonal Jacobian computations for nodal boundary conditions in the Multiphysics Object Oriented Simulation Environment (MOOSE) [1] framework. There are presently a number of applications [2{5] based on the MOOSE framework that solve complicated physical systems of partial dierential equations whose boundary conditions are often highly nonlinear. Accurately computing the on- and o-diagonal Jacobian and preconditioner entries associated to these constraints is crucial for enabling ecient numerical solvers in these applications. Two key ingredients are required for properly specifying the Jacobian contributions of nonlinear nodal boundary conditions in MOOSE and nite elementmore » codes in general: 1. The ability to zero out entire Jacobian matrix rows after \

  9. Fast and accurate matrix completion via truncated nuclear norm regularization.

    PubMed

    Hu, Yao; Zhang, Debing; Ye, Jieping; Li, Xuelong; He, Xiaofei

    2013-09-01

    Recovering a large matrix from a small subset of its entries is a challenging problem arising in many real applications, such as image inpainting and recommender systems. Many existing approaches formulate this problem as a general low-rank matrix approximation problem. Since the rank operator is nonconvex and discontinuous, most of the recent theoretical studies use the nuclear norm as a convex relaxation. One major limitation of the existing approaches based on nuclear norm minimization is that all the singular values are simultaneously minimized, and thus the rank may not be well approximated in practice. In this paper, we propose to achieve a better approximation to the rank of matrix by truncated nuclear norm, which is given by the nuclear norm subtracted by the sum of the largest few singular values. In addition, we develop a novel matrix completion algorithm by minimizing the Truncated Nuclear Norm. We further develop three efficient iterative procedures, TNNR-ADMM, TNNR-APGL, and TNNR-ADMMAP, to solve the optimization problem. TNNR-ADMM utilizes the alternating direction method of multipliers (ADMM), while TNNR-AGPL applies the accelerated proximal gradient line search method (APGL) for the final optimization. For TNNR-ADMMAP, we make use of an adaptive penalty according to a novel update rule for ADMM to achieve a faster convergence rate. Our empirical study shows encouraging results of the proposed algorithms in comparison to the state-of-the-art matrix completion algorithms on both synthetic and real visual datasets.

  10. Interval-valued intuitionistic fuzzy matrix games based on Archimedean t-conorm and t-norm

    NASA Astrophysics Data System (ADS)

    Xia, Meimei

    2018-04-01

    Fuzzy game theory has been applied in many decision-making problems. The matrix game with interval-valued intuitionistic fuzzy numbers (IVIFNs) is investigated based on Archimedean t-conorm and t-norm. The existing matrix games with IVIFNs are all based on Algebraic t-conorm and t-norm, which are special cases of Archimedean t-conorm and t-norm. In this paper, the intuitionistic fuzzy aggregation operators based on Archimedean t-conorm and t-norm are employed to aggregate the payoffs of players. To derive the solution of the matrix game with IVIFNs, several mathematical programming models are developed based on Archimedean t-conorm and t-norm. The proposed models can be transformed into a pair of primal-dual linear programming models, based on which, the solution of the matrix game with IVIFNs is obtained. It is proved that the theorems being valid in the exiting matrix game with IVIFNs are still true when the general aggregation operator is used in the proposed matrix game with IVIFNs. The proposed method is an extension of the existing ones and can provide more choices for players. An example is given to illustrate the validity and the applicability of the proposed method.

  11. Schatten Matrix Norm Based Polarimetric SAR Data Regularization Application over Chamonix Mont-Blanc

    NASA Astrophysics Data System (ADS)

    Le, Thu Trang; Atto, Abdourrahmane M.; Trouve, Emmanuel

    2013-08-01

    The paper addresses the filtering of Polarimetry Synthetic Aperture Radar (PolSAR) images. The filtering strategy is based on a regularizing cost function associated with matrix norms called the Schatten p-norms. These norms apply on matrix singular values. The proposed approach is illustrated upon scattering and coherency matrices on RADARSAT-2 PolSAR images over the Chamonix Mont-Blanc site. Several p values of Schatten p-norms are surveyed and their capabilities on filtering PolSAR images is provided in comparison with conventional strategies for filtering PolSAR data.

  12. A Truncated Nuclear Norm Regularization Method Based on Weighted Residual Error for Matrix Completion.

    PubMed

    Qing Liu; Zhihui Lai; Zongwei Zhou; Fangjun Kuang; Zhong Jin

    2016-01-01

    Low-rank matrix completion aims to recover a matrix from a small subset of its entries and has received much attention in the field of computer vision. Most existing methods formulate the task as a low-rank matrix approximation problem. A truncated nuclear norm has recently been proposed as a better approximation to the rank of matrix than a nuclear norm. The corresponding optimization method, truncated nuclear norm regularization (TNNR), converges better than the nuclear norm minimization-based methods. However, it is not robust to the number of subtracted singular values and requires a large number of iterations to converge. In this paper, a TNNR method based on weighted residual error (TNNR-WRE) for matrix completion and its extension model (ETNNR-WRE) are proposed. TNNR-WRE assigns different weights to the rows of the residual error matrix in an augmented Lagrange function to accelerate the convergence of the TNNR method. The ETNNR-WRE is much more robust to the number of subtracted singular values than the TNNR-WRE, TNNR alternating direction method of multipliers, and TNNR accelerated proximal gradient with Line search methods. Experimental results using both synthetic and real visual data sets show that the proposed TNNR-WRE and ETNNR-WRE methods perform better than TNNR and Iteratively Reweighted Nuclear Norm (IRNN) methods.

  13. Adaptive Jacobian Fuzzy Attitude Control for Flexible Spacecraft Combined Attitude and Sun Tracking System

    NASA Astrophysics Data System (ADS)

    Chak, Yew-Chung; Varatharajoo, Renuganth

    2016-07-01

    Many spacecraft attitude control systems today use reaction wheels to deliver precise torques to achieve three-axis attitude stabilization. However, irrecoverable mechanical failure of reaction wheels could potentially lead to mission interruption or total loss. The electrically-powered Solar Array Drive Assemblies (SADA) are usually installed in the pitch axis which rotate the solar arrays to track the Sun, can produce torques to compensate for the pitch-axis wheel failure. In addition, the attitude control of a flexible spacecraft poses a difficult problem. These difficulties include the strong nonlinear coupled dynamics between the rigid hub and flexible solar arrays, and the imprecisely known system parameters, such as inertia matrix, damping ratios, and flexible mode frequencies. In order to overcome these drawbacks, the adaptive Jacobian tracking fuzzy control is proposed for the combined attitude and sun-tracking control problem of a flexible spacecraft during attitude maneuvers in this work. For the adaptation of kinematic and dynamic uncertainties, the proposed scheme uses an adaptive sliding vector based on estimated attitude velocity via approximate Jacobian matrix. The unknown nonlinearities are approximated by deriving the fuzzy models with a set of linguistic If-Then rules using the idea of sector nonlinearity and local approximation in fuzzy partition spaces. The uncertain parameters of the estimated nonlinearities and the Jacobian matrix are being adjusted online by an adaptive law to realize feedback control. The attitude of the spacecraft can be directly controlled with the Jacobian feedback control when the attitude pointing trajectory is designed with respect to the spacecraft coordinate frame itself. A significant feature of this work is that the proposed adaptive Jacobian tracking scheme will result in not only the convergence of angular position and angular velocity tracking errors, but also the convergence of estimated angular velocity to

  14. Numerical implementation, verification and validation of two-phase flow four-equation drift flux model with Jacobian-free Newton–Krylov method

    DOE PAGES

    Zou, Ling; Zhao, Haihua; Zhang, Hongbin

    2016-08-24

    This study presents a numerical investigation on using the Jacobian-free Newton–Krylov (JFNK) method to solve the two-phase flow four-equation drift flux model with realistic constitutive correlations (‘closure models’). The drift flux model is based on Isshi and his collaborators’ work. Additional constitutive correlations for vertical channel flow, such as two-phase flow pressure drop, flow regime map, wall boiling and interfacial heat transfer models, were taken from the RELAP5-3D Code Manual and included to complete the model. The staggered grid finite volume method and fully implicit backward Euler method was used for the spatial discretization and time integration schemes, respectively. Themore » Jacobian-free Newton–Krylov method shows no difficulty in solving the two-phase flow drift flux model with a discrete flow regime map. In addition to the Jacobian-free approach, the preconditioning matrix is obtained by using the default finite differencing method provided in the PETSc package, and consequently the labor-intensive implementation of complex analytical Jacobian matrix is avoided. Extensive and successful numerical verification and validation have been performed to prove the correct implementation of the models and methods. Code-to-code comparison with RELAP5-3D has further demonstrated the successful implementation of the drift flux model.« less

  15. Multi-GPU Jacobian accelerated computing for soft-field tomography.

    PubMed

    Borsic, A; Attardo, E A; Halter, R J

    2012-10-01

    Image reconstruction in soft-field tomography is based on an inverse problem formulation, where a forward model is fitted to the data. In medical applications, where the anatomy presents complex shapes, it is common to use finite element models (FEMs) to represent the volume of interest and solve a partial differential equation that models the physics of the system. Over the last decade, there has been a shifting interest from 2D modeling to 3D modeling, as the underlying physics of most problems are 3D. Although the increased computational power of modern computers allows working with much larger FEM models, the computational time required to reconstruct 3D images on a fine 3D FEM model can be significant, on the order of hours. For example, in electrical impedance tomography (EIT) applications using a dense 3D FEM mesh with half a million elements, a single reconstruction iteration takes approximately 15-20 min with optimized routines running on a modern multi-core PC. It is desirable to accelerate image reconstruction to enable researchers to more easily and rapidly explore data and reconstruction parameters. Furthermore, providing high-speed reconstructions is essential for some promising clinical application of EIT. For 3D problems, 70% of the computing time is spent building the Jacobian matrix, and 25% of the time in forward solving. In this work, we focus on accelerating the Jacobian computation by using single and multiple GPUs. First, we discuss an optimized implementation on a modern multi-core PC architecture and show how computing time is bounded by the CPU-to-memory bandwidth; this factor limits the rate at which data can be fetched by the CPU. Gains associated with the use of multiple CPU cores are minimal, since data operands cannot be fetched fast enough to saturate the processing power of even a single CPU core. GPUs have much faster memory bandwidths compared to CPUs and better parallelism. We are able to obtain acceleration factors of 20

  16. Multi-GPU Jacobian Accelerated Computing for Soft Field Tomography

    PubMed Central

    Borsic, A.; Attardo, E. A.; Halter, R. J.

    2012-01-01

    Image reconstruction in soft-field tomography is based on an inverse problem formulation, where a forward model is fitted to the data. In medical applications, where the anatomy presents complex shapes, it is common to use Finite Element Models to represent the volume of interest and to solve a partial differential equation that models the physics of the system. Over the last decade, there has been a shifting interest from 2D modeling to 3D modeling, as the underlying physics of most problems are three-dimensional. Though the increased computational power of modern computers allows working with much larger FEM models, the computational time required to reconstruct 3D images on a fine 3D FEM model can be significant, on the order of hours. For example, in Electrical Impedance Tomography applications using a dense 3D FEM mesh with half a million elements, a single reconstruction iteration takes approximately 15 to 20 minutes with optimized routines running on a modern multi-core PC. It is desirable to accelerate image reconstruction to enable researchers to more easily and rapidly explore data and reconstruction parameters. Further, providing high-speed reconstructions are essential for some promising clinical application of EIT. For 3D problems 70% of the computing time is spent building the Jacobian matrix, and 25% of the time in forward solving. In the present work, we focus on accelerating the Jacobian computation by using single and multiple GPUs. First, we discuss an optimized implementation on a modern multi-core PC architecture and show how computing time is bounded by the CPU-to-memory bandwidth; this factor limits the rate at which data can be fetched by the CPU. Gains associated with use of multiple CPU cores are minimal, since data operands cannot be fetched fast enough to saturate the processing power of even a single CPU core. GPUs have a much faster memory bandwidths compared to CPUs and better parallelism. We are able to obtain acceleration factors of

  17. Jacobian-free approximate solvers for hyperbolic systems: Application to relativistic magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Castro, Manuel J.; Gallardo, José M.; Marquina, Antonio

    2017-10-01

    We present recent advances in PVM (Polynomial Viscosity Matrix) methods based on internal approximations to the absolute value function, and compare them with Chebyshev-based PVM solvers. These solvers only require a bound on the maximum wave speed, so no spectral decomposition is needed. Another important feature of the proposed methods is that they are suitable to be written in Jacobian-free form, in which only evaluations of the physical flux are used. This is particularly interesting when considering systems for which the Jacobians involve complex expressions, e.g., the relativistic magnetohydrodynamics (RMHD) equations. On the other hand, the proposed Jacobian-free solvers have also been extended to the case of approximate DOT (Dumbser-Osher-Toro) methods, which can be regarded as simple and efficient approximations to the classical Osher-Solomon method, sharing most of it interesting features and being applicable to general hyperbolic systems. To test the properties of our schemes a number of numerical experiments involving the RMHD equations are presented, both in one and two dimensions. The obtained results are in good agreement with those found in the literature and show that our schemes are robust and accurate, running stable under a satisfactory time step restriction. It is worth emphasizing that, although this work focuses on RMHD, the proposed schemes are suitable to be applied to general hyperbolic systems.

  18. Efficient l1 -norm-based low-rank matrix approximations for large-scale problems using alternating rectified gradient method.

    PubMed

    Kim, Eunwoo; Lee, Minsik; Choi, Chong-Ho; Kwak, Nojun; Oh, Songhwai

    2015-02-01

    Low-rank matrix approximation plays an important role in the area of computer vision and image processing. Most of the conventional low-rank matrix approximation methods are based on the l2 -norm (Frobenius norm) with principal component analysis (PCA) being the most popular among them. However, this can give a poor approximation for data contaminated by outliers (including missing data), because the l2 -norm exaggerates the negative effect of outliers. Recently, to overcome this problem, various methods based on the l1 -norm, such as robust PCA methods, have been proposed for low-rank matrix approximation. Despite the robustness of the methods, they require heavy computational effort and substantial memory for high-dimensional data, which is impractical for real-world problems. In this paper, we propose two efficient low-rank factorization methods based on the l1 -norm that find proper projection and coefficient matrices using the alternating rectified gradient method. The proposed methods are applied to a number of low-rank matrix approximation problems to demonstrate their efficiency and robustness. The experimental results show that our proposals are efficient in both execution time and reconstruction performance unlike other state-of-the-art methods.

  19. Bilinear Factor Matrix Norm Minimization for Robust PCA: Algorithms and Applications.

    PubMed

    Shang, Fanhua; Cheng, James; Liu, Yuanyuan; Luo, Zhi-Quan; Lin, Zhouchen

    2017-09-04

    The heavy-tailed distributions of corrupted outliers and singular values of all channels in low-level vision have proven effective priors for many applications such as background modeling, photometric stereo and image alignment. And they can be well modeled by a hyper-Laplacian. However, the use of such distributions generally leads to challenging non-convex, non-smooth and non-Lipschitz problems, and makes existing algorithms very slow for large-scale applications. Together with the analytic solutions to Lp-norm minimization with two specific values of p, i.e., p=1/2 and p=2/3, we propose two novel bilinear factor matrix norm minimization models for robust principal component analysis. We first define the double nuclear norm and Frobenius/nuclear hybrid norm penalties, and then prove that they are in essence the Schatten-1/2 and 2/3 quasi-norms, respectively, which lead to much more tractable and scalable Lipschitz optimization problems. Our experimental analysis shows that both our methods yield more accurate solutions than original Schatten quasi-norm minimization, even when the number of observations is very limited. Finally, we apply our penalties to various low-level vision problems, e.g. moving object detection, image alignment and inpainting, and show that our methods usually outperform the state-of-the-art methods.

  20. A Newton-Krylov method with an approximate analytical Jacobian for implicit solution of Navier-Stokes equations on staggered overset-curvilinear grids with immersed boundaries.

    PubMed

    Asgharzadeh, Hafez; Borazjani, Iman

    2017-02-15

    The explicit and semi-implicit schemes in flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates. Implicit schemes can be used to overcome these restrictions, but implementing them to solve the Navier-Stokes equations is not straightforward due to their non-linearity. Among the implicit schemes for nonlinear equations, Newton-based techniques are preferred over fixed-point techniques because of their high convergence rate but each Newton iteration is more expensive than a fixed-point iteration. Krylov subspace methods are one of the most advanced iterative methods that can be combined with Newton methods, i.e., Newton-Krylov Methods (NKMs) to solve non-linear systems of equations. The success of NKMs vastly depends on the scheme for forming the Jacobian, e.g., automatic differentiation is very expensive, and matrix-free methods without a preconditioner slow down as the mesh is refined. A novel, computationally inexpensive analytical Jacobian for NKM is developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered overset-curvilinear grids with immersed boundaries. Moreover, the analytical Jacobian is used to form preconditioner for matrix-free method in order to improve its performance. The NKM with the analytical Jacobian was validated and verified against Taylor-Green vortex, inline oscillations of a cylinder in a fluid initially at rest, and pulsatile flow in a 90 degree bend. The capability of the method in handling complex geometries with multiple overset grids and immersed boundaries is shown by simulating an intracranial aneurysm. It was shown that the NKM with an analytical Jacobian is 1.17 to 14.77 times faster than the fixed-point Runge-Kutta method, and 1.74 to 152.3 times (excluding an intensively stretched grid) faster than automatic differentiation depending on the grid (size) and the flow problem. In addition, it was shown that using only the

  1. A Newton–Krylov method with an approximate analytical Jacobian for implicit solution of Navier–Stokes equations on staggered overset-curvilinear grids with immersed boundaries

    PubMed Central

    Asgharzadeh, Hafez; Borazjani, Iman

    2016-01-01

    The explicit and semi-implicit schemes in flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates. Implicit schemes can be used to overcome these restrictions, but implementing them to solve the Navier-Stokes equations is not straightforward due to their non-linearity. Among the implicit schemes for nonlinear equations, Newton-based techniques are preferred over fixed-point techniques because of their high convergence rate but each Newton iteration is more expensive than a fixed-point iteration. Krylov subspace methods are one of the most advanced iterative methods that can be combined with Newton methods, i.e., Newton-Krylov Methods (NKMs) to solve non-linear systems of equations. The success of NKMs vastly depends on the scheme for forming the Jacobian, e.g., automatic differentiation is very expensive, and matrix-free methods without a preconditioner slow down as the mesh is refined. A novel, computationally inexpensive analytical Jacobian for NKM is developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered overset-curvilinear grids with immersed boundaries. Moreover, the analytical Jacobian is used to form preconditioner for matrix-free method in order to improve its performance. The NKM with the analytical Jacobian was validated and verified against Taylor-Green vortex, inline oscillations of a cylinder in a fluid initially at rest, and pulsatile flow in a 90 degree bend. The capability of the method in handling complex geometries with multiple overset grids and immersed boundaries is shown by simulating an intracranial aneurysm. It was shown that the NKM with an analytical Jacobian is 1.17 to 14.77 times faster than the fixed-point Runge-Kutta method, and 1.74 to 152.3 times (excluding an intensively stretched grid) faster than automatic differentiation depending on the grid (size) and the flow problem. In addition, it was shown that using only the

  2. A Newton-Krylov method with an approximate analytical Jacobian for implicit solution of Navier-Stokes equations on staggered overset-curvilinear grids with immersed boundaries

    NASA Astrophysics Data System (ADS)

    Asgharzadeh, Hafez; Borazjani, Iman

    2017-02-01

    The explicit and semi-implicit schemes in flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates. Implicit schemes can be used to overcome these restrictions, but implementing them to solve the Navier-Stokes equations is not straightforward due to their non-linearity. Among the implicit schemes for non-linear equations, Newton-based techniques are preferred over fixed-point techniques because of their high convergence rate but each Newton iteration is more expensive than a fixed-point iteration. Krylov subspace methods are one of the most advanced iterative methods that can be combined with Newton methods, i.e., Newton-Krylov Methods (NKMs) to solve non-linear systems of equations. The success of NKMs vastly depends on the scheme for forming the Jacobian, e.g., automatic differentiation is very expensive, and matrix-free methods without a preconditioner slow down as the mesh is refined. A novel, computationally inexpensive analytical Jacobian for NKM is developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered overset-curvilinear grids with immersed boundaries. Moreover, the analytical Jacobian is used to form a preconditioner for matrix-free method in order to improve its performance. The NKM with the analytical Jacobian was validated and verified against Taylor-Green vortex, inline oscillations of a cylinder in a fluid initially at rest, and pulsatile flow in a 90 degree bend. The capability of the method in handling complex geometries with multiple overset grids and immersed boundaries is shown by simulating an intracranial aneurysm. It was shown that the NKM with an analytical Jacobian is 1.17 to 14.77 times faster than the fixed-point Runge-Kutta method, and 1.74 to 152.3 times (excluding an intensively stretched grid) faster than automatic differentiation depending on the grid (size) and the flow problem. In addition, it was shown that using only the

  3. A new family Jacobian solver for global three-dimensional modeling of atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    Zhao, Xuepeng; Turco, Richard P.; Shen, Mei

    1999-01-01

    We present a new technique to solve complex sets of photochemical rate equations that is applicable to global modeling of the troposphere and stratosphere. The approach is based on the concept of "families" of species, whose chemical rate equations are tightly coupled. Variations of species concentrations within a family can be determined by inverting a linearized Jacobian matrix representing the family group. Since this group consists of a relatively small number of species the corresponding Jacobian has a low order (a minimatrix) compared to the Jacobian of the entire system. However, we go further and define a super-family that is the set of all families. The super-family is also solved by linearization and matrix inversion. The resulting Super-Family Matrix Inversion (SFMI) scheme is more stable and accurate than common family approaches. We discuss the numerical structure of the SFMI scheme and apply our algorithms to a comprehensive set of photochemical reactions. To evaluate performance, the SFMI scheme is compared with an optimized Gear solver. We find that the SFMI technique can be at least an order of magnitude more efficient than existing chemical solvers while maintaining relative errors in the calculations of 15% or less over a diurnal cycle. The largest SFMI errors arise at sunrise and sunset and during the evening when species concentrations may be very low. We show that sunrise/sunset errors can be minimized through a careful treatment of photodissociation during these periods; the nighttime deviations are negligible from the point of view of acceptable computational accuracy. The stability and flexibility of the SFMI algorithm should be sufficient for most modeling applications until major improvements in other modeling factors are achieved. In addition, because of its balanced computational design, SFMI can easily be adapted to parallel computing architectures. SFMI thus should allow practical long-term integrations of global chemistry coupled to

  4. Implicit solution of Navier-Stokes equations on staggered curvilinear grids using a Newton-Krylov method with a novel analytical Jacobian.

    NASA Astrophysics Data System (ADS)

    Borazjani, Iman; Asgharzadeh, Hafez

    2015-11-01

    Flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates with explicit and semi-implicit schemes. Implicit schemes can be used to overcome these restrictions. However, implementing implicit solver for nonlinear equations including Navier-Stokes is not straightforward. Newton-Krylov subspace methods (NKMs) are one of the most advanced iterative methods to solve non-linear equations such as implicit descritization of the Navier-Stokes equation. The efficiency of NKMs massively depends on the Jacobian formation method, e.g., automatic differentiation is very expensive, and matrix-free methods slow down as the mesh is refined. Analytical Jacobian is inexpensive method, but derivation of analytical Jacobian for Navier-Stokes equation on staggered grid is challenging. The NKM with a novel analytical Jacobian was developed and validated against Taylor-Green vortex and pulsatile flow in a 90 degree bend. The developed method successfully handled the complex geometries such as an intracranial aneurysm with multiple overset grids, and immersed boundaries. It is shown that the NKM with an analytical Jacobian is 3 to 25 times faster than the fixed-point implicit Runge-Kutta method, and more than 100 times faster than automatic differentiation depending on the grid (size) and the flow problem. The developed methods are fully parallelized with parallel efficiency of 80-90% on the problems tested.

  5. Algorithmic vs. finite difference Jacobians for infrared atmospheric radiative transfer

    NASA Astrophysics Data System (ADS)

    Schreier, Franz; Gimeno García, Sebastián; Vasquez, Mayte; Xu, Jian

    2015-10-01

    Jacobians, i.e. partial derivatives of the radiance and transmission spectrum with respect to the atmospheric state parameters to be retrieved from remote sensing observations, are important for the iterative solution of the nonlinear inverse problem. Finite difference Jacobians are easy to implement, but computationally expensive and possibly of dubious quality; on the other hand, analytical Jacobians are accurate and efficient, but the implementation can be quite demanding. GARLIC, our "Generic Atmospheric Radiation Line-by-line Infrared Code", utilizes algorithmic differentiation (AD) techniques to implement derivatives w.r.t. atmospheric temperature and molecular concentrations. In this paper, we describe our approach for differentiation of the high resolution infrared and microwave spectra and provide an in-depth assessment of finite difference approximations using "exact" AD Jacobians as a reference. The results indicate that the "standard" two-point finite differences with 1 K and 1% perturbation for temperature and volume mixing ratio, respectively, can exhibit substantial errors, and central differences are significantly better. However, these deviations do not transfer into the truncated singular value decomposition solution of a least squares problem. Nevertheless, AD Jacobians are clearly recommended because of the superior speed and accuracy.

  6. Recovery Discontinuous Galerkin Jacobian-Free Newton-Krylov Method for All-Speed Flows

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    HyeongKae Park; Robert Nourgaliev; Vincent Mousseau

    2008-07-01

    A novel numerical algorithm (rDG-JFNK) for all-speed fluid flows with heat conduction and viscosity is introduced. The rDG-JFNK combines the Discontinuous Galerkin spatial discretization with the implicit Runge-Kutta time integration under the Jacobian-free Newton-Krylov framework. We solve fully-compressible Navier-Stokes equations without operator-splitting of hyperbolic, diffusion and reaction terms, which enables fully-coupled high-order temporal discretization. The stability constraint is removed due to the L-stable Explicit, Singly Diagonal Implicit Runge-Kutta (ESDIRK) scheme. The governing equations are solved in the conservative form, which allows one to accurately compute shock dynamics, as well as low-speed flows. For spatial discretization, we develop a “recovery” familymore » of DG, exhibiting nearly-spectral accuracy. To precondition the Krylov-based linear solver (GMRES), we developed an “Operator-Split”-(OS) Physics Based Preconditioner (PBP), in which we transform/simplify the fully-coupled system to a sequence of segregated scalar problems, each can be solved efficiently with Multigrid method. Each scalar problem is designed to target/cluster eigenvalues of the Jacobian matrix associated with a specific physics.« less

  7. Methods for calculating the electrode position Jacobian for impedance imaging.

    PubMed

    Boyle, A; Crabb, M G; Jehl, M; Lionheart, W R B; Adler, A

    2017-03-01

    Electrical impedance tomography (EIT) or electrical resistivity tomography (ERT) current and measure voltages at the boundary of a domain through electrodes. The movement or incorrect placement of electrodes may lead to modelling errors that result in significant reconstructed image artifacts. These errors may be accounted for by allowing for electrode position estimates in the model. Movement may be reconstructed through a first-order approximation, the electrode position Jacobian. A reconstruction that incorporates electrode position estimates and conductivity can significantly reduce image artifacts. Conversely, if electrode position is ignored it can be difficult to distinguish true conductivity changes from reconstruction artifacts which may increase the risk of a flawed interpretation. In this work, we aim to determine the fastest, most accurate approach for estimating the electrode position Jacobian. Four methods of calculating the electrode position Jacobian were evaluated on a homogeneous halfspace. Results show that Fréchet derivative and rank-one update methods are competitive in computational efficiency but achieve different solutions for certain values of contact impedance and mesh density.

  8. On the use of finite difference matrix-vector products in Newton-Krylov solvers for implicit climate dynamics with spectral elements

    DOE PAGES

    Woodward, Carol S.; Gardner, David J.; Evans, Katherine J.

    2015-01-01

    Efficient solutions of global climate models require effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a step size governed by accuracy of the processes of interest rather than by stability of the fastest time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton's method is applied to solve these systems. Each iteration of the Newton's method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but thismore » Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite difference approximation which may introduce inaccuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite difference approximations of these matrix-vector products for climate dynamics within the spectral element shallow water dynamical core of the Community Atmosphere Model.« less

  9. Efficient Jacobian inversion for the control of simple robot manipulators

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Bejczy, Antal K.

    1988-01-01

    Symbolic inversion of the Jacobian matrix for spherical wrist arms is investigated. It is shown that, taking advantage of the simple geometry of these arms, the closed-form solution of the system Q = J-1X, representing a transformation from task space to joint space, can be obtained very efficiently. The solutions for PUMA, Stanford, and a six-revolute-joint coplanar arm, along with all singular points, are presented. The solution for each joint variable is found as an explicit function of the singular points which provides a better insight into the effect of different singular points on the motion and force exertion of each individual joint. For the above arms, the computation cost of the solution is on the same order as the cost of forward kinematic solution and it is significantly reduced if forward kinematic solution is already obtained. A comparison with previous methods shows that this method is the most efficient to date.

  10. 1-norm support vector novelty detection and its sparseness.

    PubMed

    Zhang, Li; Zhou, WeiDa

    2013-12-01

    This paper proposes a 1-norm support vector novelty detection (SVND) method and discusses its sparseness. 1-norm SVND is formulated as a linear programming problem and uses two techniques for inducing sparseness, or the 1-norm regularization and the hinge loss function. We also find two upper bounds on the sparseness of 1-norm SVND, or exact support vector (ESV) and kernel Gram matrix rank bounds. The ESV bound indicates that 1-norm SVND has a sparser representation model than SVND. The kernel Gram matrix rank bound can loosely estimate the sparseness of 1-norm SVND. Experimental results show that 1-norm SVND is feasible and effective. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Evaluation of the observation operator Jacobian for leaf area index data assimilation with an extended Kalman filter

    NASA Astrophysics Data System (ADS)

    Rüdiger, Christoph; Albergel, CléMent; Mahfouf, Jean-FrançOis; Calvet, Jean-Christophe; Walker, Jeffrey P.

    2010-05-01

    To quantify carbon and water fluxes between the vegetation and the atmosphere in a consistent manner, land surface models now include interactive vegetation components. These models treat the vegetation biomass as a prognostic model state, allowing the model to dynamically adapt the vegetation states to environmental conditions. However, it is expected that the prediction skill of such models can be greatly increased by assimilating biophysical observations such as leaf area index (LAI). The Jacobian of the observation operator, a central aspect of data assimilation methods such as the extended Kalman filter (EKF) and the variational assimilation methods, provides the required linear relationship between the observation and the model states. In this paper, the Jacobian required for assimilating LAI into the Interaction between the Soil, Biosphere and Atmosphere-A-gs land surface model using the EKF is studied. In particular, sensitivity experiments were undertaken on the size of the initial perturbation for estimating the Jacobian and on the length of the time window between initial state and available observation. It was found that small perturbations (0.1% of the state) typically lead to accurate estimates of the Jacobian. While other studies have shown that the assimilation of LAI with 10 day assimilation windows is possible, 1 day assimilation intervals can be chosen to comply with numerical weather prediction requirements. Moreover, the seasonal dependence of the Jacobian revealed contrasted groups of Jacobian values due to environmental factors. Further analyses showed the Jacobian values to vary as a function of the LAI itself, which has important implications for its assimilation in different seasons, as the size of the LAI increments will subsequently vary due to the variability of the Jacobian.

  12. WE-AB-202-03: Quantifying Ventilation Change Due to Radiation Therapy Using 4DCT Jacobian Calculations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patton, T; Du, K; Bayouth, J

    Purpose: Four-dimensional computed tomography (4DCT) and image registration can be used to determine regional lung ventilation changes after radiation therapy (RT). This study aimed to determine if lung ventilation change following radiation therapy was affected by the pre-RT ventilation of the lung. Methods: 13 subjects had three 4DCT scans: two repeat scans acquired before RT and one three months after RT. Regional ventilation was computed using Jacobian determinant calculations on the registered 4DCT images. The post-RT ventilation map was divided by the pre-RT ventilation map to get a voxel-by-voxel Jacobian ratio map depicting ventilation change over the course of RT.more » Jacobian ratio change was compared over the range of delivered doses. The first pre-RT ventilation image was divided by the second to establish a control for Jacobian ratio change without radiation delivered. The functional change between scans was assessed using histograms of the Jacobian ratios. Results: There were significantly (p < 0.05) more voxels that had a large decrease in Jacobian ratio in the post-RT divided by pre-RT map (15.6%) than the control (13.2%). There were also significantly (p < .01) more voxels that had a large increase in Jacobian ratio (16.2%) when compared to control (13.3%). Lung regions with low function (<10% expansion by Jacobian) showed a slight linear reduction in expansion (0.2%/10 Gy delivered), while high function regions (>10% expansion) showed a greater response (1.2% reduction/10 Gy). Contiguous high function regions > 1 liter occurred in 11 of 13 subjects. Conclusion: There is a significant change in regional ventilation following a course of radiation therapy. The change in Jacobian following RT is dependent both on the delivered dose and the initial ventilation of the lung tissue: high functioning lung has greater ventilation loss for equivalent radiation doses. Substantial regions of high function lung tissue are prevalent. Research support from

  13. Exploring Strange Nonchaotic Attractors through Jacobian Elliptic Functions

    ERIC Educational Resources Information Center

    Garcia-Hoz, A. Martinez; Chacon, R.

    2011-01-01

    We demonstrate the effectiveness of Jacobian elliptic functions (JEFs) for inquiring into the reshaping effect of quasiperiodic forces in nonlinear nonautonomous systems exhibiting strange nonchaotic attractors (SNAs). Specifically, we characterize analytically and numerically some reshaping-induced transitions starting from SNAs in the context of…

  14. TU-G-BRA-03: Predicting Radiation Therapy Induced Ventilation Changes Using 4DCT Jacobian Calculations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patton, T; Du, K; Bayouth, J

    2015-06-15

    Purpose: Longitudinal changes in lung ventilation following radiation therapy can be mapped using four-dimensional computed tomography(4DCT) and image registration. This study aimed to predict ventilation changes caused by radiation therapy(RT) as a function of pre-RT ventilation and delivered dose. Methods: 4DCT images were acquired before and 3 months after radiation therapy for 13 subjects. Jacobian ventilation maps were calculated from the 4DCT images, warped to a common coordinate system, and a Jacobian ratio map was computed voxel-by-voxel as the ratio of post-RT to pre-RT Jacobian calculations. A leave-one-out method was used to build a response model for each subject: post-RTmore » to pre-RT Jacobian ratio data and dose distributions of 12 subjects were applied to the subject’s pre-RT Jacobian map to predict the post-RT Jacobian. The predicted Jacobian map was compared to the actual post-RT Jacobian map to evaluate efficacy. Within this cohort, 8 subjects had repeat pre-RT scans that were compared as a reference for no ventilation change. Maps were compared using gamma pass rate criteria of 2mm distance-to-agreement and 6% ventilation difference. Gamma pass rates were compared using paired t-tests to determine significant differences. Further analysis masked non-radiation induced changes by excluding voxels below specified dose thresholds. Results: Visual inspection demonstrates the predicted post-RT ventilation map is similar to the actual map in magnitude and distribution. Quantitatively, the percentage of voxels in agreement when excluding voxels receiving below specified doses are: 74%/20Gy, 73%/10Gy, 73%/5Gy, and 71%/0Gy. By comparison, repeat scans produced 73% of voxels within the 6%/2mm criteria. The agreement of the actual post-RT maps with the predicted maps was significantly better than agreement with pre-RT maps (p<0.02). Conclusion: This work validates that significant changes to ventilation post-RT can be predicted. The differences between

  15. Flux Jacobian Matrices For Equilibrium Real Gases

    NASA Technical Reports Server (NTRS)

    Vinokur, Marcel

    1990-01-01

    Improved formulation includes generalized Roe average and extension to three dimensions. Flux Jacobian matrices derived for use in numerical solutions of conservation-law differential equations of inviscid flows of ideal gases extended to real gases. Real-gas formulation of these matrices retains simplifying assumptions of thermodynamic and chemical equilibrium, but adds effects of vibrational excitation, dissociation, and ionization of gas molecules via general equation of state.

  16. Spanish semantic feature production norms for 400 concrete concepts.

    PubMed

    Vivas, Jorge; Vivas, Leticia; Comesaña, Ana; Coni, Ana García; Vorano, Agostina

    2017-06-01

    Semantic feature production norms provide many quantitative measures of different feature and concept variables that are necessary to solve some debates surrounding the nature of the organization, both normal and pathological, of semantic memory. Despite the current existence of norms for different languages, there are still no published norms in Spanish. This article presents a new set of norms collected from 810 participants for 400 living and nonliving concepts among Spanish speakers. These norms consist of empirical collections of features that participants used to describe the concepts. Four files were elaborated: a concept-feature file, a concept-concept matrix, a feature-feature matrix, and a significantly correlated features file. We expect that these norms will be useful for researchers in the fields of experimental psychology, neuropsychology, and psycholinguistics.

  17. Hessian Schatten-norm regularization for linear inverse problems.

    PubMed

    Lefkimmiatis, Stamatios; Ward, John Paul; Unser, Michael

    2013-05-01

    We introduce a novel family of invariant, convex, and non-quadratic functionals that we employ to derive regularized solutions of ill-posed linear inverse imaging problems. The proposed regularizers involve the Schatten norms of the Hessian matrix, which are computed at every pixel of the image. They can be viewed as second-order extensions of the popular total-variation (TV) semi-norm since they satisfy the same invariance properties. Meanwhile, by taking advantage of second-order derivatives, they avoid the staircase effect, a common artifact of TV-based reconstructions, and perform well for a wide range of applications. To solve the corresponding optimization problems, we propose an algorithm that is based on a primal-dual formulation. A fundamental ingredient of this algorithm is the projection of matrices onto Schatten norm balls of arbitrary radius. This operation is performed efficiently based on a direct link we provide between vector projections onto lq norm balls and matrix projections onto Schatten norm balls. Finally, we demonstrate the effectiveness of the proposed methods through experimental results on several inverse imaging problems with real and simulated data.

  18. New preconditioning strategy for Jacobian-free solvers for variably saturated flows with Richards’ equation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lipnikov, Konstantin; Moulton, David; Svyatskiy, Daniil

    2016-04-29

    We develop a new approach for solving the nonlinear Richards’ equation arising in variably saturated flow modeling. The growing complexity of geometric models for simulation of subsurface flows leads to the necessity of using unstructured meshes and advanced discretization methods. Typically, a numerical solution is obtained by first discretizing PDEs and then solving the resulting system of nonlinear discrete equations with a Newton-Raphson-type method. Efficiency and robustness of the existing solvers rely on many factors, including an empiric quality control of intermediate iterates, complexity of the employed discretization method and a customized preconditioner. We propose and analyze a new preconditioningmore » strategy that is based on a stable discretization of the continuum Jacobian. We will show with numerical experiments for challenging problems in subsurface hydrology that this new preconditioner improves convergence of the existing Jacobian-free solvers 3-20 times. Furthermore, we show that the Picard method with this preconditioner becomes a more efficient nonlinear solver than a few widely used Jacobian-free solvers.« less

  19. Optimization of computations for adjoint field and Jacobian needed in 3D CSEM inversion

    NASA Astrophysics Data System (ADS)

    Dehiya, Rahul; Singh, Arun; Gupta, Pravin K.; Israil, M.

    2017-01-01

    We present the features and results of a newly developed code, based on Gauss-Newton optimization technique, for solving three-dimensional Controlled-Source Electromagnetic inverse problem. In this code a special emphasis has been put on representing the operations by block matrices for conjugate gradient iteration. We show how in the computation of Jacobian, the matrix formed by differentiation of system matrix can be made independent of frequency to optimize the operations at conjugate gradient step. The coarse level parallel computing, using OpenMP framework, is used primarily due to its simplicity in implementation and accessibility of shared memory multi-core computing machine to almost anyone. We demonstrate how the coarseness of modeling grid in comparison to source (comp`utational receivers) spacing can be exploited for efficient computing, without compromising the quality of the inverted model, by reducing the number of adjoint calls. It is also demonstrated that the adjoint field can even be computed on a grid coarser than the modeling grid without affecting the inversion outcome. These observations were reconfirmed using an experiment design where the deviation of source from straight tow line is considered. Finally, a real field data inversion experiment is presented to demonstrate robustness of the code.

  20. Robust Principal Component Analysis Regularized by Truncated Nuclear Norm for Identifying Differentially Expressed Genes.

    PubMed

    Wang, Ya-Xuan; Gao, Ying-Lian; Liu, Jin-Xing; Kong, Xiang-Zhen; Li, Hai-Jun

    2017-09-01

    Identifying differentially expressed genes from the thousands of genes is a challenging task. Robust principal component analysis (RPCA) is an efficient method in the identification of differentially expressed genes. RPCA method uses nuclear norm to approximate the rank function. However, theoretical studies showed that the nuclear norm minimizes all singular values, so it may not be the best solution to approximate the rank function. The truncated nuclear norm is defined as the sum of some smaller singular values, which may achieve a better approximation of the rank function than nuclear norm. In this paper, a novel method is proposed by replacing nuclear norm of RPCA with the truncated nuclear norm, which is named robust principal component analysis regularized by truncated nuclear norm (TRPCA). The method decomposes the observation matrix of genomic data into a low-rank matrix and a sparse matrix. Because the significant genes can be considered as sparse signals, the differentially expressed genes are viewed as the sparse perturbation signals. Thus, the differentially expressed genes can be identified according to the sparse matrix. The experimental results on The Cancer Genome Atlas data illustrate that the TRPCA method outperforms other state-of-the-art methods in the identification of differentially expressed genes.

  1. A cut-&-paste strategy for the 3-D inversion of helicopter-borne electromagnetic data - I. 3-D inversion using the explicit Jacobian and a tensor-based formulation

    NASA Astrophysics Data System (ADS)

    Scheunert, M.; Ullmann, A.; Afanasjew, M.; Börner, R.-U.; Siemon, B.; Spitzer, K.

    2016-06-01

    We present an inversion concept for helicopter-borne frequency-domain electromagnetic (HEM) data capable of reconstructing 3-D conductivity structures in the subsurface. Standard interpretation procedures often involve laterally constrained stitched 1-D inversion techniques to create pseudo-3-D models that are largely representative for smoothly varying conductivity distributions in the subsurface. Pronounced lateral conductivity changes may, however, produce significant artifacts that can lead to serious misinterpretation. Still, 3-D inversions of entire survey data sets are numerically very expensive. Our approach is therefore based on a cut-&-paste strategy whereupon the full 3-D inversion needs to be applied only to those parts of the survey where the 1-D inversion actually fails. The introduced 3-D Gauss-Newton inversion scheme exploits information given by a state-of-the-art (laterally constrained) 1-D inversion. For a typical HEM measurement, an explicit representation of the Jacobian matrix is inevitable which is caused by the unique transmitter-receiver relation. We introduce tensor quantities which facilitate the matrix assembly of the forward operator as well as the efficient calculation of the Jacobian. The finite difference forward operator incorporates the displacement currents because they may seriously affect the electromagnetic response at frequencies above 100. Finally, we deliver the proof of concept for the inversion using a synthetic data set with a noise level of up to 5%.

  2. Application of a Modal Approach in Solving the Static Stability Problem for Electric Power Systems

    NASA Astrophysics Data System (ADS)

    Sharov, J. V.

    2017-12-01

    Application of a modal approach in solving the static stability problem for power systems is examined. It is proposed to use the matrix exponent norm as a generalized transition function of the power system disturbed motion. Based on the concept of a stability radius and the pseudospectrum of Jacobian matrix, the necessary and sufficient conditions for existence of the static margins were determined. The capabilities and advantages of the modal approach in designing centralized or distributed control and the prospects for the analysis of nonlinear oscillations and rendering the dynamic stability are demonstrated.

  3. Nonconvex Nonsmooth Low Rank Minimization via Iteratively Reweighted Nuclear Norm.

    PubMed

    Lu, Canyi; Tang, Jinhui; Yan, Shuicheng; Lin, Zhouchen

    2016-02-01

    The nuclear norm is widely used as a convex surrogate of the rank function in compressive sensing for low rank matrix recovery with its applications in image recovery and signal processing. However, solving the nuclear norm-based relaxed convex problem usually leads to a suboptimal solution of the original rank minimization problem. In this paper, we propose to use a family of nonconvex surrogates of L0-norm on the singular values of a matrix to approximate the rank function. This leads to a nonconvex nonsmooth minimization problem. Then, we propose to solve the problem by an iteratively re-weighted nuclear norm (IRNN) algorithm. IRNN iteratively solves a weighted singular value thresholding problem, which has a closed form solution due to the special properties of the nonconvex surrogate functions. We also extend IRNN to solve the nonconvex problem with two or more blocks of variables. In theory, we prove that the IRNN decreases the objective function value monotonically, and any limit point is a stationary point. Extensive experiments on both synthesized data and real images demonstrate that IRNN enhances the low rank matrix recovery compared with the state-of-the-art convex algorithms.

  4. Trace Norm Regularized CANDECOMP/PARAFAC Decomposition With Missing Data.

    PubMed

    Liu, Yuanyuan; Shang, Fanhua; Jiao, Licheng; Cheng, James; Cheng, Hong

    2015-11-01

    In recent years, low-rank tensor completion (LRTC) problems have received a significant amount of attention in computer vision, data mining, and signal processing. The existing trace norm minimization algorithms for iteratively solving LRTC problems involve multiple singular value decompositions of very large matrices at each iteration. Therefore, they suffer from high computational cost. In this paper, we propose a novel trace norm regularized CANDECOMP/PARAFAC decomposition (TNCP) method for simultaneous tensor decomposition and completion. We first formulate a factor matrix rank minimization model by deducing the relation between the rank of each factor matrix and the mode- n rank of a tensor. Then, we introduce a tractable relaxation of our rank function, and then achieve a convex combination problem of much smaller-scale matrix trace norm minimization. Finally, we develop an efficient algorithm based on alternating direction method of multipliers to solve our problem. The promising experimental results on synthetic and real-world data validate the effectiveness of our TNCP method. Moreover, TNCP is significantly faster than the state-of-the-art methods and scales to larger problems.

  5. Flux Jacobian matrices and generaled Roe average for an equilibrium real gas

    NASA Technical Reports Server (NTRS)

    Vinokur, Marcel

    1988-01-01

    Inviscid flux Jacobian matrices and their properties used in numerical solutions of conservation laws are extended to general, equilibrium gas laws. Exact and approximate generalizations of the Roe average are presented. Results are given for one-dimensional flow, and then extended to three-dimensional flow with time-varying grids.

  6. Poisson image reconstruction with Hessian Schatten-norm regularization.

    PubMed

    Lefkimmiatis, Stamatios; Unser, Michael

    2013-11-01

    Poisson inverse problems arise in many modern imaging applications, including biomedical and astronomical ones. The main challenge is to obtain an estimate of the underlying image from a set of measurements degraded by a linear operator and further corrupted by Poisson noise. In this paper, we propose an efficient framework for Poisson image reconstruction, under a regularization approach, which depends on matrix-valued regularization operators. In particular, the employed regularizers involve the Hessian as the regularization operator and Schatten matrix norms as the potential functions. For the solution of the problem, we propose two optimization algorithms that are specifically tailored to the Poisson nature of the noise. These algorithms are based on an augmented-Lagrangian formulation of the problem and correspond to two variants of the alternating direction method of multipliers. Further, we derive a link that relates the proximal map of an l(p) norm with the proximal map of a Schatten matrix norm of order p. This link plays a key role in the development of one of the proposed algorithms. Finally, we provide experimental results on natural and biological images for the task of Poisson image deblurring and demonstrate the practical relevance and effectiveness of the proposed framework.

  7. Fast calculation of the `ILC norm' in iterative learning control

    NASA Astrophysics Data System (ADS)

    Rice, Justin K.; van Wingerden, Jan-Willem

    2013-06-01

    In this paper, we discuss and demonstrate a method for the exploitation of matrix structure in computations for iterative learning control (ILC). In Barton, Bristow, and Alleyne [International Journal of Control, 83(2), 1-8 (2010)], a special insight into the structure of the lifted convolution matrices involved in ILC is used along with a modified Lanczos method to achieve very fast computational bounds on the learning convergence, by calculating the 'ILC norm' in ? computational complexity. In this paper, we show how their method is equivalent to a special instance of the sequentially semi-separable (SSS) matrix arithmetic, and thus can be extended to many other computations in ILC, and specialised in some cases to even faster methods. Our SSS-based methodology will be demonstrated on two examples: a linear time-varying example resulting in the same ? complexity as in Barton et al., and a linear time-invariant example where our approach reduces the computational complexity to ?, thus decreasing the computation time, for an example, from the literature by a factor of almost 100. This improvement is achieved by transforming the norm computation via a linear matrix inequality into a check of positive definiteness - which allows us to further exploit the almost-Toeplitz properties of the matrix, and additionally provides explicit upper and lower bounds on the norm of the matrix, instead of the indirect Ritz estimate. These methods are now implemented in a MATLAB toolbox, freely available on the Internet.

  8. A matrix contraction process

    NASA Astrophysics Data System (ADS)

    Wilkinson, Michael; Grant, John

    2018-03-01

    We consider a stochastic process in which independent identically distributed random matrices are multiplied and where the Lyapunov exponent of the product is positive. We continue multiplying the random matrices as long as the norm, ɛ, of the product is less than unity. If the norm is greater than unity we reset the matrix to a multiple of the identity and then continue the multiplication. We address the problem of determining the probability density function of the norm, \

  9. Reduced rank regression via adaptive nuclear norm penalization

    PubMed Central

    Chen, Kun; Dong, Hongbo; Chan, Kung-Sik

    2014-01-01

    Summary We propose an adaptive nuclear norm penalization approach for low-rank matrix approximation, and use it to develop a new reduced rank estimation method for high-dimensional multivariate regression. The adaptive nuclear norm is defined as the weighted sum of the singular values of the matrix, and it is generally non-convex under the natural restriction that the weight decreases with the singular value. However, we show that the proposed non-convex penalized regression method has a global optimal solution obtained from an adaptively soft-thresholded singular value decomposition. The method is computationally efficient, and the resulting solution path is continuous. The rank consistency of and prediction/estimation performance bounds for the estimator are established for a high-dimensional asymptotic regime. Simulation studies and an application in genetics demonstrate its efficacy. PMID:25045172

  10. Linear discriminant analysis based on L1-norm maximization.

    PubMed

    Zhong, Fujin; Zhang, Jiashu

    2013-08-01

    Linear discriminant analysis (LDA) is a well-known dimensionality reduction technique, which is widely used for many purposes. However, conventional LDA is sensitive to outliers because its objective function is based on the distance criterion using L2-norm. This paper proposes a simple but effective robust LDA version based on L1-norm maximization, which learns a set of local optimal projection vectors by maximizing the ratio of the L1-norm-based between-class dispersion and the L1-norm-based within-class dispersion. The proposed method is theoretically proved to be feasible and robust to outliers while overcoming the singular problem of the within-class scatter matrix for conventional LDA. Experiments on artificial datasets, standard classification datasets and three popular image databases demonstrate the efficacy of the proposed method.

  11. Sparse nonnegative matrix factorization with ℓ0-constraints

    PubMed Central

    Peharz, Robert; Pernkopf, Franz

    2012-01-01

    Although nonnegative matrix factorization (NMF) favors a sparse and part-based representation of nonnegative data, there is no guarantee for this behavior. Several authors proposed NMF methods which enforce sparseness by constraining or penalizing the ℓ1-norm of the factor matrices. On the other hand, little work has been done using a more natural sparseness measure, the ℓ0-pseudo-norm. In this paper, we propose a framework for approximate NMF which constrains the ℓ0-norm of the basis matrix, or the coefficient matrix, respectively. For this purpose, techniques for unconstrained NMF can be easily incorporated, such as multiplicative update rules, or the alternating nonnegative least-squares scheme. In experiments we demonstrate the benefits of our methods, which compare to, or outperform existing approaches. PMID:22505792

  12. Jacobian-Based Iterative Method for Magnetic Localization in Robotic Capsule Endoscopy

    PubMed Central

    Di Natali, Christian; Beccani, Marco; Simaan, Nabil; Valdastri, Pietro

    2016-01-01

    The purpose of this study is to validate a Jacobian-based iterative method for real-time localization of magnetically controlled endoscopic capsules. The proposed approach applies finite-element solutions to the magnetic field problem and least-squares interpolations to obtain closed-form and fast estimates of the magnetic field. By defining a closed-form expression for the Jacobian of the magnetic field relative to changes in the capsule pose, we are able to obtain an iterative localization at a faster computational time when compared with prior works, without suffering from the inaccuracies stemming from dipole assumptions. This new algorithm can be used in conjunction with an absolute localization technique that provides initialization values at a slower refresh rate. The proposed approach was assessed via simulation and experimental trials, adopting a wireless capsule equipped with a permanent magnet, six magnetic field sensors, and an inertial measurement unit. The overall refresh rate, including sensor data acquisition and wireless communication was 7 ms, thus enabling closed-loop control strategies for magnetic manipulation running faster than 100 Hz. The average localization error, expressed in cylindrical coordinates was below 7 mm in both the radial and axial components and 5° in the azimuthal component. The average error for the capsule orientation angles, obtained by fusing gyroscope and inclinometer measurements, was below 5°. PMID:27087799

  13. Multivariable frequency domain identification via 2-norm minimization

    NASA Technical Reports Server (NTRS)

    Bayard, David S.

    1992-01-01

    The author develops a computational approach to multivariable frequency domain identification, based on 2-norm minimization. In particular, a Gauss-Newton (GN) iteration is developed to minimize the 2-norm of the error between frequency domain data and a matrix fraction transfer function estimate. To improve the global performance of the optimization algorithm, the GN iteration is initialized using the solution to a particular sequentially reweighted least squares problem, denoted as the SK iteration. The least squares problems which arise from both the SK and GN iterations are shown to involve sparse matrices with identical block structure. A sparse matrix QR factorization method is developed to exploit the special block structure, and to efficiently compute the least squares solution. A numerical example involving the identification of a multiple-input multiple-output (MIMO) plant having 286 unknown parameters is given to illustrate the effectiveness of the algorithm.

  14. Evaluation of Jacobian determinants by Monte Carlo methods: Application to the quasiclassical approximation in molecular scattering

    NASA Technical Reports Server (NTRS)

    Labudde, R. A.

    1971-01-01

    A technique is described which can be used to evaluate Jacobian determinants which occur in classical mechanical and quasiclassical approximation descriptions of molecular scattering. The method may be valuable in the study of reactive scattering using the quasiclassical approximation.

  15. Solving phase appearance/disappearance two-phase flow problems with high resolution staggered grid and fully implicit schemes by the Jacobian-free Newton–Krylov Method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zou, Ling; Zhao, Haihua; Zhang, Hongbin

    2016-04-01

    The phase appearance/disappearance issue presents serious numerical challenges in two-phase flow simulations. Many existing reactor safety analysis codes use different kinds of treatments for the phase appearance/disappearance problem. However, to our best knowledge, there are no fully satisfactory solutions. Additionally, the majority of the existing reactor system analysis codes were developed using low-order numerical schemes in both space and time. In many situations, it is desirable to use high-resolution spatial discretization and fully implicit time integration schemes to reduce numerical errors. In this work, we adapted a high-resolution spatial discretization scheme on staggered grid mesh and fully implicit time integrationmore » methods (such as BDF1 and BDF2) to solve the two-phase flow problems. The discretized nonlinear system was solved by the Jacobian-free Newton Krylov (JFNK) method, which does not require the derivation and implementation of analytical Jacobian matrix. These methods were tested with a few two-phase flow problems with phase appearance/disappearance phenomena considered, such as a linear advection problem, an oscillating manometer problem, and a sedimentation problem. The JFNK method demonstrated extremely robust and stable behaviors in solving the two-phase flow problems with phase appearance/disappearance. No special treatments such as water level tracking or void fraction limiting were used. High-resolution spatial discretization and second- order fully implicit method also demonstrated their capabilities in significantly reducing numerical errors.« less

  16. Characterizing species interactions to understand press perturbations: What is the community matrix?

    USGS Publications Warehouse

    Novak, Mark; Yeakel, Justin D.; Noble, Andrew E.; Doak, Daniel F.; Emmerson, Mark; Estes, James A.; Jacob, Ute; Tinker, M. Tim; Wootton, J. Timothy

    2016-01-01

    The community matrix is among ecology's most important mathematical abstractions, formally encapsulating the interconnected network of effects that species have on one another's populations. Despite its importance, the term `community matrix' has been applied to matrices having differing interpretations. This has hindered the application of theory for understanding community structure and perturbation responses, particularly in the contexts of ecosystem-based management and conservation. Here we clarify the correspondence and distinctions between the Interaction matrix, the Alpha matrix and the Jacobian matrix, terms which are frequently used interchangeably and have numerous synonyms, including the term Community matrix. We illustrate how these matrices correspond to different ways of characterizing interaction strengths, how they permit insights regarding different types of press perturbations of species growth rates or abundances, and how these are related by a simple scaling relationship. Connections to additional interaction strength characterizations encapsulated by the Beta matrix, the Gamma matrix, and the Removal matrix are also discussed. Our synthesis highlights the empirical challenges that remain in using these mathematical tools to understand actual communities.

  17. On the sparseness of 1-norm support vector machines.

    PubMed

    Zhang, Li; Zhou, Weida

    2010-04-01

    There is some empirical evidence available showing that 1-norm Support Vector Machines (1-norm SVMs) have good sparseness; however, both how good sparseness 1-norm SVMs can reach and whether they have a sparser representation than that of standard SVMs are not clear. In this paper we take into account the sparseness of 1-norm SVMs. Two upper bounds on the number of nonzero coefficients in the decision function of 1-norm SVMs are presented. First, the number of nonzero coefficients in 1-norm SVMs is at most equal to the number of only the exact support vectors lying on the +1 and -1 discriminating surfaces, while that in standard SVMs is equal to the number of support vectors, which implies that 1-norm SVMs have better sparseness than that of standard SVMs. Second, the number of nonzero coefficients is at most equal to the rank of the sample matrix. A brief review of the geometry of linear programming and the primal steepest edge pricing simplex method are given, which allows us to provide the proof of the two upper bounds and evaluate their tightness by experiments. Experimental results on toy data sets and the UCI data sets illustrate our analysis. Copyright 2009 Elsevier Ltd. All rights reserved.

  18. Chow groups of intersections of quadrics via homological projective duality and (Jacobians of) non-commutative motives

    NASA Astrophysics Data System (ADS)

    Bernardara, M.; Tabuada, G.

    2016-06-01

    Conjectures of Beilinson-Bloch type predict that the low-degree rational Chow groups of intersections of quadrics are one-dimensional. This conjecture was proved by Otwinowska in [20]. By making use of homological projective duality and the recent theory of (Jacobians of) non-commutative motives, we give an alternative proof of this conjecture in the case of a complete intersection of either two quadrics or three odd-dimensional quadrics. Moreover, we prove that in these cases the unique non-trivial algebraic Jacobian is the middle one. As an application, we make use of Vial's work [26], [27] to describe the rational Chow motives of these complete intersections and show that smooth fibrations into such complete intersections over bases S of small dimension satisfy Murre's conjecture (when \\dim (S)≤ 1), Grothendieck's standard conjecture of Lefschetz type (when \\dim (S)≤ 2), and Hodge's conjecture (when \\dim(S)≤ 3).

  19. Nuclear norm-based 2-DPCA for extracting features from images.

    PubMed

    Zhang, Fanlong; Yang, Jian; Qian, Jianjun; Xu, Yong

    2015-10-01

    The 2-D principal component analysis (2-DPCA) is a widely used method for image feature extraction. However, it can be equivalently implemented via image-row-based principal component analysis. This paper presents a structured 2-D method called nuclear norm-based 2-DPCA (N-2-DPCA), which uses a nuclear norm-based reconstruction error criterion. The nuclear norm is a matrix norm, which can provide a structured 2-D characterization for the reconstruction error image. The reconstruction error criterion is minimized by converting the nuclear norm-based optimization problem into a series of F-norm-based optimization problems. In addition, N-2-DPCA is extended to a bilateral projection-based N-2-DPCA (N-B2-DPCA). The virtue of N-B2-DPCA over N-2-DPCA is that an image can be represented with fewer coefficients. N-2-DPCA and N-B2-DPCA are applied to face recognition and reconstruction and evaluated using the Extended Yale B, CMU PIE, FRGC, and AR databases. Experimental results demonstrate the effectiveness of the proposed methods.

  20. Generalizations of Tikhonov's regularized method of least squares to non-Euclidean vector norms

    NASA Astrophysics Data System (ADS)

    Volkov, V. V.; Erokhin, V. I.; Kakaev, V. V.; Onufrei, A. Yu.

    2017-09-01

    Tikhonov's regularized method of least squares and its generalizations to non-Euclidean norms, including polyhedral, are considered. The regularized method of least squares is reduced to mathematical programming problems obtained by "instrumental" generalizations of the Tikhonov lemma on the minimal (in a certain norm) solution of a system of linear algebraic equations with respect to an unknown matrix. Further studies are needed for problems concerning the development of methods and algorithms for solving reduced mathematical programming problems in which the objective functions and admissible domains are constructed using polyhedral vector norms.

  1. Statistical analysis of latent generalized correlation matrix estimation in transelliptical distribution.

    PubMed

    Han, Fang; Liu, Han

    2017-02-01

    Correlation matrix plays a key role in many multivariate methods (e.g., graphical model estimation and factor analysis). The current state-of-the-art in estimating large correlation matrices focuses on the use of Pearson's sample correlation matrix. Although Pearson's sample correlation matrix enjoys various good properties under Gaussian models, its not an effective estimator when facing heavy-tail distributions with possible outliers. As a robust alternative, Han and Liu (2013b) advocated the use of a transformed version of the Kendall's tau sample correlation matrix in estimating high dimensional latent generalized correlation matrix under the transelliptical distribution family (or elliptical copula). The transelliptical family assumes that after unspecified marginal monotone transformations, the data follow an elliptical distribution. In this paper, we study the theoretical properties of the Kendall's tau sample correlation matrix and its transformed version proposed in Han and Liu (2013b) for estimating the population Kendall's tau correlation matrix and the latent Pearson's correlation matrix under both spectral and restricted spectral norms. With regard to the spectral norm, we highlight the role of "effective rank" in quantifying the rate of convergence. With regard to the restricted spectral norm, we for the first time present a "sign subgaussian condition" which is sufficient to guarantee that the rank-based correlation matrix estimator attains the optimal rate of convergence. In both cases, we do not need any moment condition.

  2. From Norm Adoption to Norm Internalization

    NASA Astrophysics Data System (ADS)

    Conte, Rosaria; Andrighetto, Giulia; Villatoro, Daniel

    In this presentation, advances in modeling the mental dynamics of norms will be presented. In particular, the process from norm-adoption, possibly yielding new normative goals, to different forms of norm compliance will be focused upon, including norm internalization, which is at study in social-behavioral sciences and moral philosophy since long. Of late, the debate was revamped within the rationality approach pointing to the role of norm internalization as a less costly and more reliable enforcement system than social control. So far, poor attention was paid to the mental underpinnings of internalization. In this presentation, a rich cognitive model of different types, degrees and factors of internalization is shown. The initial implementation of this model on EMIL-A, a normative agent architecture developed and applied to the.

  3. A P-Norm Robust Feature Extraction Method for Identifying Differentially Expressed Genes

    PubMed Central

    Liu, Jian; Liu, Jin-Xing; Gao, Ying-Lian; Kong, Xiang-Zhen; Wang, Xue-Song; Wang, Dong

    2015-01-01

    In current molecular biology, it becomes more and more important to identify differentially expressed genes closely correlated with a key biological process from gene expression data. In this paper, based on the Schatten p-norm and Lp-norm, a novel p-norm robust feature extraction method is proposed to identify the differentially expressed genes. In our method, the Schatten p-norm is used as the regularization function to obtain a low-rank matrix and the Lp-norm is taken as the error function to improve the robustness to outliers in the gene expression data. The results on simulation data show that our method can obtain higher identification accuracies than the competitive methods. Numerous experiments on real gene expression data sets demonstrate that our method can identify more differentially expressed genes than the others. Moreover, we confirmed that the identified genes are closely correlated with the corresponding gene expression data. PMID:26201006

  4. A P-Norm Robust Feature Extraction Method for Identifying Differentially Expressed Genes.

    PubMed

    Liu, Jian; Liu, Jin-Xing; Gao, Ying-Lian; Kong, Xiang-Zhen; Wang, Xue-Song; Wang, Dong

    2015-01-01

    In current molecular biology, it becomes more and more important to identify differentially expressed genes closely correlated with a key biological process from gene expression data. In this paper, based on the Schatten p-norm and Lp-norm, a novel p-norm robust feature extraction method is proposed to identify the differentially expressed genes. In our method, the Schatten p-norm is used as the regularization function to obtain a low-rank matrix and the Lp-norm is taken as the error function to improve the robustness to outliers in the gene expression data. The results on simulation data show that our method can obtain higher identification accuracies than the competitive methods. Numerous experiments on real gene expression data sets demonstrate that our method can identify more differentially expressed genes than the others. Moreover, we confirmed that the identified genes are closely correlated with the corresponding gene expression data.

  5. The Twist Tensor Nuclear Norm for Video Completion.

    PubMed

    Hu, Wenrui; Tao, Dacheng; Zhang, Wensheng; Xie, Yuan; Yang, Yehui

    2017-12-01

    In this paper, we propose a new low-rank tensor model based on the circulant algebra, namely, twist tensor nuclear norm (t-TNN). The twist tensor denotes a three-way tensor representation to laterally store 2-D data slices in order. On one hand, t-TNN convexly relaxes the tensor multirank of the twist tensor in the Fourier domain, which allows an efficient computation using fast Fourier transform. On the other, t-TNN is equal to the nuclear norm of block circulant matricization of the twist tensor in the original domain, which extends the traditional matrix nuclear norm in a block circulant way. We test the t-TNN model on a video completion application that aims to fill missing values and the experiment results validate its effectiveness, especially when dealing with video recorded by a nonstationary panning camera. The block circulant matricization of the twist tensor can be transformed into a circulant block representation with nuclear norm invariance. This representation, after transformation, exploits the horizontal translation relationship between the frames in a video, and endows the t-TNN model with a more powerful ability to reconstruct panning videos than the existing state-of-the-art low-rank models.

  6. Three-dimensional magnetotelluric inversion including topography using deformed hexahedral edge finite elements, direct solvers and data space Gauss-Newton, parallelized on SMP computers

    NASA Astrophysics Data System (ADS)

    Kordy, M. A.; Wannamaker, P. E.; Maris, V.; Cherkaev, E.; Hill, G. J.

    2014-12-01

    We have developed an algorithm for 3D simulation and inversion of magnetotelluric (MT) responses using deformable hexahedral finite elements that permits incorporation of topography. Direct solvers parallelized on symmetric multiprocessor (SMP), single-chassis workstations with large RAM are used for the forward solution, parameter jacobians, and model update. The forward simulator, jacobians calculations, as well as synthetic and real data inversion are presented. We use first-order edge elements to represent the secondary electric field (E), yielding accuracy O(h) for E and its curl (magnetic field). For very low frequency or small material admittivity, the E-field requires divergence correction. Using Hodge decomposition, correction may be applied after the forward solution is calculated. It allows accurate E-field solutions in dielectric air. The system matrix factorization is computed using the MUMPS library, which shows moderately good scalability through 12 processor cores but limited gains beyond that. The factored matrix is used to calculate the forward response as well as the jacobians of field and MT responses using the reciprocity theorem. Comparison with other codes demonstrates accuracy of our forward calculations. We consider a popular conductive/resistive double brick structure and several topographic models. In particular, the ability of finite elements to represent smooth topographic slopes permits accurate simulation of refraction of electromagnetic waves normal to the slopes at high frequencies. Run time tests indicate that for meshes as large as 150x150x60 elements, MT forward response and jacobians can be calculated in ~2.5 hours per frequency. For inversion, we implemented data space Gauss-Newton method, which offers reduction in memory requirement and a significant speedup of the parameter step versus model space approach. For dense matrix operations we use tiling approach of PLASMA library, which shows very good scalability. In synthetic

  7. Statistical analysis of latent generalized correlation matrix estimation in transelliptical distribution

    PubMed Central

    Han, Fang; Liu, Han

    2016-01-01

    Correlation matrix plays a key role in many multivariate methods (e.g., graphical model estimation and factor analysis). The current state-of-the-art in estimating large correlation matrices focuses on the use of Pearson’s sample correlation matrix. Although Pearson’s sample correlation matrix enjoys various good properties under Gaussian models, its not an effective estimator when facing heavy-tail distributions with possible outliers. As a robust alternative, Han and Liu (2013b) advocated the use of a transformed version of the Kendall’s tau sample correlation matrix in estimating high dimensional latent generalized correlation matrix under the transelliptical distribution family (or elliptical copula). The transelliptical family assumes that after unspecified marginal monotone transformations, the data follow an elliptical distribution. In this paper, we study the theoretical properties of the Kendall’s tau sample correlation matrix and its transformed version proposed in Han and Liu (2013b) for estimating the population Kendall’s tau correlation matrix and the latent Pearson’s correlation matrix under both spectral and restricted spectral norms. With regard to the spectral norm, we highlight the role of “effective rank” in quantifying the rate of convergence. With regard to the restricted spectral norm, we for the first time present a “sign subgaussian condition” which is sufficient to guarantee that the rank-based correlation matrix estimator attains the optimal rate of convergence. In both cases, we do not need any moment condition. PMID:28337068

  8. Robust and Efficient Biomolecular Clustering of Tumor Based on ${p}$ -Norm Singular Value Decomposition.

    PubMed

    Kong, Xiang-Zhen; Liu, Jin-Xing; Zheng, Chun-Hou; Hou, Mi-Xiao; Wang, Juan

    2017-07-01

    High dimensionality has become a typical feature of biomolecular data. In this paper, a novel dimension reduction method named p-norm singular value decomposition (PSVD) is proposed to seek the low-rank approximation matrix to the biomolecular data. To enhance the robustness to outliers, the Lp-norm is taken as the error function and the Schatten p-norm is used as the regularization function in the optimization model. To evaluate the performance of PSVD, the Kmeans clustering method is then employed for tumor clustering based on the low-rank approximation matrix. Extensive experiments are carried out on five gene expression data sets including two benchmark data sets and three higher dimensional data sets from the cancer genome atlas. The experimental results demonstrate that the PSVD-based method outperforms many existing methods. Especially, it is experimentally proved that the proposed method is more efficient for processing higher dimensional data with good robustness, stability, and superior time performance.

  9. Reconstructing Norms

    ERIC Educational Resources Information Center

    Gorgorio, Nuria; Planas, Nuria

    2005-01-01

    Starting from the constructs "cultural scripts" and "social representations", and on the basis of the empirical research we have been developing until now, we revisit the construct norms from a sociocultural perspective. Norms, both sociomathematical norms and norms of the mathematical practice, as cultural scripts influenced…

  10. OPERATOR NORM INEQUALITIES BETWEEN TENSOR UNFOLDINGS ON THE PARTITION LATTICE

    PubMed Central

    Wang, Miaoyan; Duc, Khanh Dao; Fischer, Jonathan; Song, Yun S.

    2017-01-01

    Interest in higher-order tensors has recently surged in data-intensive fields, with a wide range of applications including image processing, blind source separation, community detection, and feature extraction. A common paradigm in tensor-related algorithms advocates unfolding (or flattening) the tensor into a matrix and applying classical methods developed for matrices. Despite the popularity of such techniques, how the functional properties of a tensor changes upon unfolding is currently not well understood. In contrast to the body of existing work which has focused almost exclusively on matricizations, we here consider all possible unfoldings of an order-k tensor, which are in one-to-one correspondence with the set of partitions of {1, …, k}. We derive general inequalities between the lp-norms of arbitrary unfoldings defined on the partition lattice. In particular, we demonstrate how the spectral norm (p = 2) of a tensor is bounded by that of its unfoldings, and obtain an improved upper bound on the ratio of the Frobenius norm to the spectral norm of an arbitrary tensor. For specially-structured tensors satisfying a generalized definition of orthogonal decomposability, we prove that the spectral norm remains invariant under specific subsets of unfolding operations. PMID:28286347

  11. OPERATOR NORM INEQUALITIES BETWEEN TENSOR UNFOLDINGS ON THE PARTITION LATTICE.

    PubMed

    Wang, Miaoyan; Duc, Khanh Dao; Fischer, Jonathan; Song, Yun S

    2017-05-01

    Interest in higher-order tensors has recently surged in data-intensive fields, with a wide range of applications including image processing, blind source separation, community detection, and feature extraction. A common paradigm in tensor-related algorithms advocates unfolding (or flattening) the tensor into a matrix and applying classical methods developed for matrices. Despite the popularity of such techniques, how the functional properties of a tensor changes upon unfolding is currently not well understood. In contrast to the body of existing work which has focused almost exclusively on matricizations, we here consider all possible unfoldings of an order- k tensor, which are in one-to-one correspondence with the set of partitions of {1, …, k }. We derive general inequalities between the l p -norms of arbitrary unfoldings defined on the partition lattice. In particular, we demonstrate how the spectral norm ( p = 2) of a tensor is bounded by that of its unfoldings, and obtain an improved upper bound on the ratio of the Frobenius norm to the spectral norm of an arbitrary tensor. For specially-structured tensors satisfying a generalized definition of orthogonal decomposability, we prove that the spectral norm remains invariant under specific subsets of unfolding operations.

  12. Extensive theoretical/numerical comparative studies on H2 and generalised H2 norms in sampled-data systems

    NASA Astrophysics Data System (ADS)

    Kim, Jung Hoon; Hagiwara, Tomomichi

    2017-11-01

    This paper is concerned with linear time-invariant (LTI) sampled-data systems (by which we mean sampled-data systems with LTI generalised plants and LTI controllers) and studies their H2 norms from the viewpoint of impulse responses and generalised H2 norms from the viewpoint of the induced norms from L2 to L∞. A new definition of the H2 norm of LTI sampled-data systems is first introduced through a sort of intermediate standpoint of those for the existing two definitions. We then establish unified treatment of the three definitions of the H2 norm through a matrix function G(τ) defined on the sampling interval [0, h). This paper next considers the generalised H2 norms, in which two types of the L∞ norm of the output are considered as the temporal supremum magnitude under the spatial 2-norm and ∞-norm of a vector-valued function. We further give unified treatment of the generalised H2 norms through another matrix function F(θ) which is also defined on [0, h). Through a close connection between G(τ) and F(θ), some theoretical relationships between the H2 and generalised H2 norms are provided. Furthermore, appropriate extensions associated with the treatment of G(τ) and F(θ) to the closed interval [0, h] are discussed to facilitate numerical computations and comparisons of the H2 and generalised H2 norms. Through theoretical and numerical studies, it is shown that the two generalised H2 norms coincide with neither of the three H2 norms of LTI sampled-data systems even though all the five definitions coincide with each other when single-output continuous-time LTI systems are considered as a special class of LTI sampled-data systems. To summarise, this paper clarifies that the five control performance measures are mutually related with each other but they are also intrinsically different from each other.

  13. A norm knockout method on indirect reciprocity to reveal indispensable norms

    NASA Astrophysics Data System (ADS)

    Yamamoto, Hitoshi; Okada, Isamu; Uchida, Satoshi; Sasaki, Tatsuya

    2017-03-01

    Although various norms for reciprocity-based cooperation have been suggested that are evolutionarily stable against invasion from free riders, the process of alternation of norms and the role of diversified norms remain unclear in the evolution of cooperation. We clarify the co-evolutionary dynamics of norms and cooperation in indirect reciprocity and also identify the indispensable norms for the evolution of cooperation. Inspired by the gene knockout method, a genetic engineering technique, we developed the norm knockout method and clarified the norms necessary for the establishment of cooperation. The results of numerical investigations revealed that the majority of norms gradually transitioned to tolerant norms after defectors are eliminated by strict norms. Furthermore, no cooperation emerges when specific norms that are intolerant to defectors are knocked out.

  14. A norm knockout method on indirect reciprocity to reveal indispensable norms

    PubMed Central

    Yamamoto, Hitoshi; Okada, Isamu; Uchida, Satoshi; Sasaki, Tatsuya

    2017-01-01

    Although various norms for reciprocity-based cooperation have been suggested that are evolutionarily stable against invasion from free riders, the process of alternation of norms and the role of diversified norms remain unclear in the evolution of cooperation. We clarify the co-evolutionary dynamics of norms and cooperation in indirect reciprocity and also identify the indispensable norms for the evolution of cooperation. Inspired by the gene knockout method, a genetic engineering technique, we developed the norm knockout method and clarified the norms necessary for the establishment of cooperation. The results of numerical investigations revealed that the majority of norms gradually transitioned to tolerant norms after defectors are eliminated by strict norms. Furthermore, no cooperation emerges when specific norms that are intolerant to defectors are knocked out. PMID:28276485

  15. Extending the Mertonian Norms: Scientists' Subscription to Norms of Research

    ERIC Educational Resources Information Center

    Anderson, Melissa S.; Ronning, Emily A.; De Vries, Raymond; Martinson, Brian C.

    2010-01-01

    This analysis, based on focus groups and a national survey, assesses scientists' subscription to the Mertonian norms of science and associated counternorms. It also supports extension of these norms to governance (as opposed to administration), as a norm of decision-making, and quality (as opposed to quantity), as an evaluative norm. (Contains 1…

  16. Direction of Arrival Estimation for MIMO Radar via Unitary Nuclear Norm Minimization

    PubMed Central

    Wang, Xianpeng; Huang, Mengxing; Wu, Xiaoqin; Bi, Guoan

    2017-01-01

    In this paper, we consider the direction of arrival (DOA) estimation issue of noncircular (NC) source in multiple-input multiple-output (MIMO) radar and propose a novel unitary nuclear norm minimization (UNNM) algorithm. In the proposed method, the noncircular properties of signals are used to double the virtual array aperture, and the real-valued data are obtained by utilizing unitary transformation. Then a real-valued block sparse model is established based on a novel over-complete dictionary, and a UNNM algorithm is formulated for recovering the block-sparse matrix. In addition, the real-valued NC-MUSIC spectrum is used to design a weight matrix for reweighting the nuclear norm minimization to achieve the enhanced sparsity of solutions. Finally, the DOA is estimated by searching the non-zero blocks of the recovered matrix. Because of using the noncircular properties of signals to extend the virtual array aperture and an additional real structure to suppress the noise, the proposed method provides better performance compared with the conventional sparse recovery based algorithms. Furthermore, the proposed method can handle the case of underdetermined DOA estimation. Simulation results show the effectiveness and advantages of the proposed method. PMID:28441770

  17. Social Norms: Do We Love Norms Too Much?

    PubMed

    Bell, David C; Cox, Mary L

    2015-03-01

    Social norms are often cited as the cause of many social phenomena, especially as an explanation for prosocial family and relationship behaviors. And yet maybe we love the idea of social norms too much, as suggested by our failure to subject them to rigorous test. Compared to the detail in social norms theoretical orientations, there is very little detail in tests of normative theories. To provide guidance to researchers who invoke social norms as explanations, we catalog normative orientations that have been proposed to account for consistent patterns of action. We call on researchers to conduct tests of normative theories and the processes such theories assert.

  18. Social Norms: Do We Love Norms Too Much?

    PubMed Central

    Bell, David C.; Cox, Mary L.

    2014-01-01

    Social norms are often cited as the cause of many social phenomena, especially as an explanation for prosocial family and relationship behaviors. And yet maybe we love the idea of social norms too much, as suggested by our failure to subject them to rigorous test. Compared to the detail in social norms theoretical orientations, there is very little detail in tests of normative theories. To provide guidance to researchers who invoke social norms as explanations, we catalog normative orientations that have been proposed to account for consistent patterns of action. We call on researchers to conduct tests of normative theories and the processes such theories assert. PMID:25937833

  19. Tensor-GMRES method for large sparse systems of nonlinear equations

    NASA Technical Reports Server (NTRS)

    Feng, Dan; Pulliam, Thomas H.

    1994-01-01

    This paper introduces a tensor-Krylov method, the tensor-GMRES method, for large sparse systems of nonlinear equations. This method is a coupling of tensor model formation and solution techniques for nonlinear equations with Krylov subspace projection techniques for unsymmetric systems of linear equations. Traditional tensor methods for nonlinear equations are based on a quadratic model of the nonlinear function, a standard linear model augmented by a simple second order term. These methods are shown to be significantly more efficient than standard methods both on nonsingular problems and on problems where the Jacobian matrix at the solution is singular. A major disadvantage of the traditional tensor methods is that the solution of the tensor model requires the factorization of the Jacobian matrix, which may not be suitable for problems where the Jacobian matrix is large and has a 'bad' sparsity structure for an efficient factorization. We overcome this difficulty by forming and solving the tensor model using an extension of a Newton-GMRES scheme. Like traditional tensor methods, we show that the new tensor method has significant computational advantages over the analogous Newton counterpart. Consistent with Krylov subspace based methods, the new tensor method does not depend on the factorization of the Jacobian matrix. As a matter of fact, the Jacobian matrix is never needed explicitly.

  20. Radiance and Jacobian Intercomparison of Radiative Transfer Models Applied to HIRS and AMSU Channels

    NASA Technical Reports Server (NTRS)

    Garand, L.; Turner, D. S.; Larocque, M.; Bates, J.; Boukabara, S.; Brunel, P.; Chevallier, F.; Deblonde, G.; Engelen, R.; Hollingshead, M.; hide

    2000-01-01

    The goals of this study are the evaluation of current fast radiative transfer models (RTMs) and line-by-line (LBL) models. The intercomparison focuses on the modeling of 11 representative sounding channels routinely used at numerical weather prediction centers: 7 HIRS (High-resolution Infrared Sounder) and 4 AMSU (Advanced Microwave Sounding Unit) channels. Interest in this topic was evidenced by the participation of 24 scientists from 16 institutions. An ensemble of 42 diverse atmospheres was used and results compiled for 19 infrared models and 10 microwave models, including several LBL RTMs. For the first time, not only radiances, but also Jacobians (of temperature, water vapor and ozone) were compared to various LBL models for many channels. In the infrared, LBL models typically agree to within 0.05-0.15 K (standard deviation) in terms of top-of-the-atmosphere brightness temperature (BT). Individual differences up to 0.5 K still exist, systematic in some channels, and linked to the type of atmosphere in others. The best fast models emulate LBL BTs to within 0.25 K, but no model achieves this desirable level of success for all channels. The ozone modeling is particularly challenging, In the microwave, fast models generally do quite well against the LBL model to which they were tuned. However significant differences were noted among LBL models, Extending the intercomparison to the Jacobians proved very useful in detecting subtle and more obvious modeling errors. In addition, total and single gas optical depths were calculated, which provided additional insight on the nature of differences. Recommendations for future intercomparisons are suggested.

  1. Radiance and Jacobian Intercomparison of Radiative Transfer Models Applied to HIRS and AMSU Channels

    NASA Technical Reports Server (NTRS)

    Garand, L.; Turner, D. S.; Larocque, M.; Bates, J.; Boukabara, S.; Brunel, P.; Chevallier, F.; Deblonde, G.; Engelen, R.; Atlas, Robert (Technical Monitor)

    2000-01-01

    The goals of this study are the evaluation of current fast radiative transfer models (RTMs) and line-by-line (LBL) models. The intercomparison focuses on the modeling of 11 representative sounding channels routinely used at numerical weather prediction centers: seven HIRS (High-resolution Infrared Sounder) and four AMSU (Advanced Microwave Sounding Unit) channels. Interest in this topic was evidenced by the participation of 24 scientists from 16 institutions. An ensemble of 42 diverse atmospheres was used and results compiled for 19 infrared models and 10 microwave models, including several LBL RTMs. For the first time, not only radiances, but also Jacobians (of temperature, water vapor, and ozone) were compared to various LBL models for many channels. In the infrared, LBL models typically agree to within 0.05-0.15 K (standard deviation) in terms of top-of-the-atmosphere brightness temperature (BT). Individual differences up to 0.5 K still exist, systematic in some channels, and linked to the type of atmosphere in others. The best fast models emulate LBL BTs to within 0.25 K, but no model achieves this desirable level of success for all channels. The ozone modeling is particularly challenging. In the microwave, fast models generally do quite well against the LBL model to which they were tuned. However significant differences were noted among LBL models. Extending the intercomparison to the Jacobians proved very useful in detecting subtle and more obvious modeling errors. In addition, total and single gas optical depths were calculated, which provided additional insight on the nature of differences. Recommendations for future intercomparisons are suggested.

  2. Estimation of the chemical rank for the three-way data: a principal norm vector orthogonal projection approach.

    PubMed

    Hong-Ping, Xie; Jian-Hui, Jiang; Guo-Li, Shen; Ru-Qin, Yu

    2002-01-01

    A new approach for estimating the chemical rank of the three-way array called the principal norm vector orthogonal projection method has been proposed. The method is based on the fact that the chemical rank of the three-way data array is equal to one of the column space of the unfolded matrix along the spectral or chromatographic mode. A vector with maximum Frobenius norm is selected among all the column vectors of the unfolded matrix as the principal norm vector (PNV). A transformation is conducted for the column vectors with an orthogonal projection matrix formulated by PNV. The mathematical rank of the column space of the residual matrix thus obtained should decrease by one. Such orthogonal projection is carried out repeatedly till the contribution of chemical species to the signal data is all deleted. At this time the decrease of the mathematical rank would equal that of the chemical rank, and the remaining residual subspace would entirely be due to the noise contribution. The chemical rank can be estimated easily by using an F-test. The method has been used successfully to the simulated HPLC-DAD type three-way data array and two real excitation-emission fluorescence data sets of amino acid mixtures and dye mixtures. The simulation with added relatively high level noise shows that the method is robust in resisting the heteroscedastic noise. The proposed algorithm is simple and easy to program with quite light computational burden.

  3. Optimal trace inequality constants for interior penalty discontinuous Galerkin discretisations of elliptic operators using arbitrary elements with non-constant Jacobians

    NASA Astrophysics Data System (ADS)

    Owens, A. R.; Kópházi, J.; Eaton, M. D.

    2017-12-01

    In this paper, a new method to numerically calculate the trace inequality constants, which arise in the calculation of penalty parameters for interior penalty discretisations of elliptic operators, is presented. These constants are provably optimal for the inequality of interest. As their calculation is based on the solution of a generalised eigenvalue problem involving the volumetric and face stiffness matrices, the method is applicable to any element type for which these matrices can be calculated, including standard finite elements and the non-uniform rational B-splines of isogeometric analysis. In particular, the presented method does not require the Jacobian of the element to be constant, and so can be applied to a much wider variety of element shapes than are currently available in the literature. Numerical results are presented for a variety of finite element and isogeometric cases. When the Jacobian is constant, it is demonstrated that the new method produces lower penalty parameters than existing methods in the literature in all cases, which translates directly into savings in the solution time of the resulting linear system. When the Jacobian is not constant, it is shown that the naive application of existing approaches can result in penalty parameters that do not guarantee coercivity of the bilinear form, and by extension, the stability of the solution. The method of manufactured solutions is applied to a model reaction-diffusion equation with a range of parameters, and it is found that using penalty parameters based on the new trace inequality constants result in better conditioned linear systems, which can be solved approximately 11% faster than those produced by the methods from the literature.

  4. Graph-Based Norm Explanation

    NASA Astrophysics Data System (ADS)

    Croitoru, Madalina; Oren, Nir; Miles, Simon; Luck, Michael

    Norms impose obligations, permissions and prohibitions on individual agents operating as part of an organisation. Typically, the purpose of such norms is to ensure that an organisation acts in some socially (or mutually) beneficial manner, possibly at the expense of individual agent utility. In this context, agents are normaware if they are able to reason about which norms are applicable to them, and to decide whether to comply with or ignore them. While much work has focused on the creation of norm-aware agents, much less has been concerned with aiding system designers in understanding the effects of norms on a system. The ability to understand such norm effects can aid the designer in avoiding incorrect norm specification, eliminating redundant norms and reducing normative conflict. In this paper, we address the problem of norm understanding by providing explanations as to why a norm is applicable, violated, or in some other state. We make use of conceptual graph based semantics to provide a graphical representation of the norms within a system. Given knowledge of the current and historical state of the system, such a representation allows for explanation of the state of norms, showing for example why they may have been activated or violated.

  5. 3-dimensional magnetotelluric inversion including topography using deformed hexahedral edge finite elements and direct solvers parallelized on symmetric multiprocessor computers - Part II: direct data-space inverse solution

    NASA Astrophysics Data System (ADS)

    Kordy, M.; Wannamaker, P.; Maris, V.; Cherkaev, E.; Hill, G.

    2016-01-01

    Following the creation described in Part I of a deformable edge finite-element simulator for 3-D magnetotelluric (MT) responses using direct solvers, in Part II we develop an algorithm named HexMT for 3-D regularized inversion of MT data including topography. Direct solvers parallelized on large-RAM, symmetric multiprocessor (SMP) workstations are used also for the Gauss-Newton model update. By exploiting the data-space approach, the computational cost of the model update becomes much less in both time and computer memory than the cost of the forward simulation. In order to regularize using the second norm of the gradient, we factor the matrix related to the regularization term and apply its inverse to the Jacobian, which is done using the MKL PARDISO library. For dense matrix multiplication and factorization related to the model update, we use the PLASMA library which shows very good scalability across processor cores. A synthetic test inversion using a simple hill model shows that including topography can be important; in this case depression of the electric field by the hill can cause false conductors at depth or mask the presence of resistive structure. With a simple model of two buried bricks, a uniform spatial weighting for the norm of model smoothing recovered more accurate locations for the tomographic images compared to weightings which were a function of parameter Jacobians. We implement joint inversion for static distortion matrices tested using the Dublin secret model 2, for which we are able to reduce nRMS to ˜1.1 while avoiding oscillatory convergence. Finally we test the code on field data by inverting full impedance and tipper MT responses collected around Mount St Helens in the Cascade volcanic chain. Among several prominent structures, the north-south trending, eruption-controlling shear zone is clearly imaged in the inversion.

  6. Fast calculation of the sensitivity matrix in magnetic induction tomography by tetrahedral edge finite elements and the reciprocity theorem.

    PubMed

    Hollaus, K; Magele, C; Merwa, R; Scharfetter, H

    2004-02-01

    Magnetic induction tomography of biological tissue is used to reconstruct the changes in the complex conductivity distribution by measuring the perturbation of an alternating primary magnetic field. To facilitate the sensitivity analysis and the solution of the inverse problem a fast calculation of the sensitivity matrix, i.e. the Jacobian matrix, which maps the changes of the conductivity distribution onto the changes of the voltage induced in a receiver coil, is needed. The use of finite differences to determine the entries of the sensitivity matrix does not represent a feasible solution because of the high computational costs of the basic eddy current problem. Therefore, the reciprocity theorem was exploited. The basic eddy current problem was simulated by the finite element method using symmetric tetrahedral edge elements of second order. To test the method various simulations were carried out and discussed.

  7. Robust Face Recognition via Multi-Scale Patch-Based Matrix Regression.

    PubMed

    Gao, Guangwei; Yang, Jian; Jing, Xiaoyuan; Huang, Pu; Hua, Juliang; Yue, Dong

    2016-01-01

    In many real-world applications such as smart card solutions, law enforcement, surveillance and access control, the limited training sample size is the most fundamental problem. By making use of the low-rank structural information of the reconstructed error image, the so-called nuclear norm-based matrix regression has been demonstrated to be effective for robust face recognition with continuous occlusions. However, the recognition performance of nuclear norm-based matrix regression degrades greatly in the face of the small sample size problem. An alternative solution to tackle this problem is performing matrix regression on each patch and then integrating the outputs from all patches. However, it is difficult to set an optimal patch size across different databases. To fully utilize the complementary information from different patch scales for the final decision, we propose a multi-scale patch-based matrix regression scheme based on which the ensemble of multi-scale outputs can be achieved optimally. Extensive experiments on benchmark face databases validate the effectiveness and robustness of our method, which outperforms several state-of-the-art patch-based face recognition algorithms.

  8. Norm-Aware Socio-Technical Systems

    NASA Astrophysics Data System (ADS)

    Savarimuthu, Bastin Tony Roy; Ghose, Aditya

    The following sections are included: * Introduction * The Need for Norm-Aware Systems * Norms in human societies * Why should software systems be norm-aware? * Case Studies of Norm-Aware Socio-Technical Systems * Human-computer interactions * Virtual environments and multi-player online games * Extracting norms from big data and software repositories * Norms and Sustainability * Sustainability and green ICT * Norm awareness through software systems * Where To, From Here? * Conclusions

  9. Configuration control of seven-degree-of-freedom arms

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun (Inventor); Long, Mark K. (Inventor); Lee, Thomas S. (Inventor)

    1992-01-01

    A seven degree of freedom robot arm with a six degree of freedom end effector is controlled by a processor employing a 6 by 7 Jacobian matrix for defining location and orientation of the end effector in terms of the rotation angles of the joints, a 1 (or more) by 7 Jacobian matrix for defining 1 (or more) user specified kinematic functions constraining location or movement of selected portions of the arm in terms of the joint angles, the processor combining the two Jacobian matrices to produce an augmented 7 (or more) by 7 Jacobian matrix, the processor effecting control by computing in accordance with forward kinematics from the augmented 7 by 7 Jacobian matrix and from the seven joint angles of the arm a set of seven desired joint angles for transmittal to the joint servo loops of the arm. One of the kinematic functions constraints the orientation of the elbow plane of the arm. Another one of the kinematic functions minimizes a sum of gravitational torques on the joints. Still another kinematic function constrains the location of the arm to perform collision avoidance. Generically, one kinematic function minimizes a sum of selected mechanical parameters of at least some of the joints associated with weighting coefficients which may be changed during arm movement. The mechanical parameters may be velocity errors or gravity torques associated with individual joints.

  10. Contests versus Norms: Implications of Contest-Based and Norm-Based Intervention Techniques

    PubMed Central

    Bergquist, Magnus; Nilsson, Andreas; Hansla, André

    2017-01-01

    Interventions using either contests or norms can promote environmental behavioral change. Yet research on the implications of contest-based and norm-based interventions is lacking. Based on Goal-framing theory, we suggest that a contest-based intervention frames a gain goal promoting intensive but instrumental behavioral engagement. In contrast, the norm-based intervention was expected to frame a normative goal activating normative obligations for targeted and non-targeted behavior and motivation to engage in pro-environmental behaviors in the future. In two studies participants (n = 347) were randomly assigned to either a contest- or a norm-based intervention technique. Participants in the contest showed more intensive engagement in both studies. Participants in the norm-based intervention tended to report higher intentions for future energy conservation (Study 1) and higher personal norms for non-targeted pro-environmental behaviors (Study 2). These findings suggest that contest-based intervention technique frames a gain goal, while norm-based intervention frames a normative goal. PMID:29218026

  11. Contests versus Norms: Implications of Contest-Based and Norm-Based Intervention Techniques.

    PubMed

    Bergquist, Magnus; Nilsson, Andreas; Hansla, André

    2017-01-01

    Interventions using either contests or norms can promote environmental behavioral change. Yet research on the implications of contest-based and norm-based interventions is lacking. Based on Goal-framing theory, we suggest that a contest-based intervention frames a gain goal promoting intensive but instrumental behavioral engagement. In contrast, the norm-based intervention was expected to frame a normative goal activating normative obligations for targeted and non-targeted behavior and motivation to engage in pro-environmental behaviors in the future. In two studies participants ( n = 347) were randomly assigned to either a contest- or a norm-based intervention technique. Participants in the contest showed more intensive engagement in both studies. Participants in the norm-based intervention tended to report higher intentions for future energy conservation (Study 1) and higher personal norms for non-targeted pro-environmental behaviors (Study 2). These findings suggest that contest-based intervention technique frames a gain goal, while norm-based intervention frames a normative goal.

  12. Multivariate statistics of the Jacobian matrices in tensor based morphometry and their application to HIV/AIDS.

    PubMed

    Lepore, Natasha; Brun, Caroline A; Chiang, Ming-Chang; Chou, Yi-Yu; Dutton, Rebecca A; Hayashi, Kiralee M; Lopez, Oscar L; Aizenstein, Howard J; Toga, Arthur W; Becker, James T; Thompson, Paul M

    2006-01-01

    Tensor-based morphometry (TBM) is widely used in computational anatomy as a means to understand shape variation between structural brain images. A 3D nonlinear registration technique is typically used to align all brain images to a common neuroanatomical template, and the deformation fields are analyzed statistically to identify group differences in anatomy. However, the differences are usually computed solely from the determinants of the Jacobian matrices that are associated with the deformation fields computed by the registration procedure. Thus, much of the information contained within those matrices gets thrown out in the process. Only the magnitude of the expansions or contractions is examined, while the anisotropy and directional components of the changes are ignored. Here we remedy this problem by computing multivariate shape change statistics using the strain matrices. As the latter do not form a vector space, means and covariances are computed on the manifold of positive-definite matrices to which they belong. We study the brain morphology of 26 HIV/AIDS patients and 14 matched healthy control subjects using our method. The images are registered using a high-dimensional 3D fluid registration algorithm, which optimizes the Jensen-Rényi divergence, an information-theoretic measure of image correspondence. The anisotropy of the deformation is then computed. We apply a manifold version of Hotelling's T2 test to the strain matrices. Our results complement those found from the determinants of the Jacobians alone and provide greater power in detecting group differences in brain structure.

  13. The phase transition of matrix recovery from Gaussian measurements matches the minimax MSE of matrix denoising.

    PubMed

    Donoho, David L; Gavish, Matan; Montanari, Andrea

    2013-05-21

    Let X(0) be an unknown M by N matrix. In matrix recovery, one takes n < MN linear measurements y(1),…,y(n) of X(0), where y(i) = Tr(A(T)iX(0)) and each A(i) is an M by N matrix. A popular approach for matrix recovery is nuclear norm minimization (NNM): solving the convex optimization problem min ||X||*subject to y(i) =Tr(A(T)(i)X) for all 1 ≤ i ≤ n, where || · ||* denotes the nuclear norm, namely, the sum of singular values. Empirical work reveals a phase transition curve, stated in terms of the undersampling fraction δ(n,M,N) = n/(MN), rank fraction ρ=rank(X0)/min {M,N}, and aspect ratio β=M/N. Specifically when the measurement matrices Ai have independent standard Gaussian random entries, a curve δ*(ρ) = δ*(ρ;β) exists such that, if δ > δ*(ρ), NNM typically succeeds for large M,N, whereas if δ < δ*(ρ), it typically fails. An apparently quite different problem is matrix denoising in Gaussian noise, in which an unknown M by N matrix X(0) is to be estimated based on direct noisy measurements Y =X(0) + Z, where the matrix Z has independent and identically distributed Gaussian entries. A popular matrix denoising scheme solves the unconstrained optimization problem min|| Y-X||(2)(F)/2+λ||X||*. When optimally tuned, this scheme achieves the asymptotic minimax mean-squared error M(ρ;β) = lim(M,N → ∞)inf(λ)sup(rank(X) ≤ ρ · M)MSE(X,X(λ)), where M/N → . We report extensive experiments showing that the phase transition δ*(ρ) in the first problem, matrix recovery from Gaussian measurements, coincides with the minimax risk curve M(ρ)=M(ρ;β) in the second problem, matrix denoising in Gaussian noise: δ*(ρ)=M(ρ), for any rank fraction 0 < ρ < 1 (at each common aspect ratio β). Our experiments considered matrices belonging to two constraint classes: real M by N matrices, of various ranks and aspect ratios, and real symmetric positive-semidefinite N by N matrices, of various ranks.

  14. A high order accurate finite element algorithm for high Reynolds number flow prediction

    NASA Technical Reports Server (NTRS)

    Baker, A. J.

    1978-01-01

    A Galerkin-weighted residuals formulation is employed to establish an implicit finite element solution algorithm for generally nonlinear initial-boundary value problems. Solution accuracy, and convergence rate with discretization refinement, are quantized in several error norms, by a systematic study of numerical solutions to several nonlinear parabolic and a hyperbolic partial differential equation characteristic of the equations governing fluid flows. Solutions are generated using selective linear, quadratic and cubic basis functions. Richardson extrapolation is employed to generate a higher-order accurate solution to facilitate isolation of truncation error in all norms. Extension of the mathematical theory underlying accuracy and convergence concepts for linear elliptic equations is predicted for equations characteristic of laminar and turbulent fluid flows at nonmodest Reynolds number. The nondiagonal initial-value matrix structure introduced by the finite element theory is determined intrinsic to improved solution accuracy and convergence. A factored Jacobian iteration algorithm is derived and evaluated to yield a consequential reduction in both computer storage and execution CPU requirements while retaining solution accuracy.

  15. Adaptation and perceptual norms

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  16. Norms as Group-Level Constructs: Investigating School-Level Teen Pregnancy Norms and Behaviors.

    PubMed

    Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

    2014-09-01

    Social norms are a group-level phenomenon, but past quantitative research has rarely measured them in the aggregate or considered their group-level properties. We used the school-based design of the National Longitudinal Study of Adolescent Health to measure normative climates regarding teen pregnancy across 75 U.S. high schools. We distinguished between the strength of a school's norm against teen pregnancy and the consensus around that norm. School-level norm strength and dissensus were strongly (r = -0.65) and moderately (r = 0.34) associated with pregnancy prevalence within schools, respectively. Normative climate partially accounted for observed racial differences in school pregnancy prevalence, but norms were a stronger predictor than racial composition. As hypothesized, schools with both a stronger average norm against teen pregnancy and greater consensus around the norm had the lowest pregnancy prevalence. Results highlight the importance of group-level normative processes and of considering the local school environment when designing policies to reduce teen pregnancy.

  17. Robust subspace clustering via joint weighted Schatten-p norm and Lq norm minimization

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Tang, Zhenmin; Liu, Qing

    2017-05-01

    Low-rank representation (LRR) has been successfully applied to subspace clustering. However, the nuclear norm in the standard LRR is not optimal for approximating the rank function in many real-world applications. Meanwhile, the L21 norm in LRR also fails to characterize various noises properly. To address the above issues, we propose an improved LRR method, which achieves low rank property via the new formulation with weighted Schatten-p norm and Lq norm (WSPQ). Specifically, the nuclear norm is generalized to be the Schatten-p norm and different weights are assigned to the singular values, and thus it can approximate the rank function more accurately. In addition, Lq norm is further incorporated into WSPQ to model different noises and improve the robustness. An efficient algorithm based on the inexact augmented Lagrange multiplier method is designed for the formulated problem. Extensive experiments on face clustering and motion segmentation clearly demonstrate the superiority of the proposed WSPQ over several state-of-the-art methods.

  18. Norms as Group-Level Constructs: Investigating School-Level Teen Pregnancy Norms and Behaviors

    PubMed Central

    Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

    2015-01-01

    Social norms are a group-level phenomenon, but past quantitative research has rarely measured them in the aggregate or considered their group-level properties. We used the school-based design of the National Longitudinal Study of Adolescent Health to measure normative climates regarding teen pregnancy across 75 U.S. high schools. We distinguished between the strength of a school's norm against teen pregnancy and the consensus around that norm. School-level norm strength and dissensus were strongly (r = -0.65) and moderately (r = 0.34) associated with pregnancy prevalence within schools, respectively. Normative climate partially accounted for observed racial differences in school pregnancy prevalence, but norms were a stronger predictor than racial composition. As hypothesized, schools with both a stronger average norm against teen pregnancy and greater consensus around the norm had the lowest pregnancy prevalence. Results highlight the importance of group-level normative processes and of considering the local school environment when designing policies to reduce teen pregnancy. PMID:26074628

  19. Configuration control of seven degree of freedom arms

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun (Inventor)

    1995-01-01

    A seven-degree-of-freedom robot arm with a six-degree-of-freedom end effector is controlled by a processor employing a 6-by-7 Jacobian matrix for defining location and orientation of the end effector in terms of the rotation angles of the joints, a 1 (or more)-by-7 Jacobian matrix for defining 1 (or more) user-specified kinematic functions constraining location or movement of selected portions of the arm in terms of the joint angles, the processor combining the two Jacobian matrices to produce an augmented 7 (or more)-by-7 Jacobian matrix, the processor effecting control by computing in accordance with forward kinematics from the augmented 7-by-7 Jacobian matrix and from the seven joint angles of the arm a set of seven desired joint angles for transmittal to the joint servo loops of the arms. One of the kinematic functions constrains the orientation of the elbow plane of the arm. Another one of the kinematic functions minimizing a sum of gravitational torques on the joints. Still another one of the kinematic functions constrains the location of the arm to perform collision avoidance. Generically, one of the kinematic functions minimizes a sum of selected mechanical parameters of at least some of the joints associated with weighting coefficients which may be changed during arm movement. The mechanical parameters may be velocity errors or position errors or gravity torques associated with individual joints.

  20. Stable Estimation of a Covariance Matrix Guided by Nuclear Norm Penalties

    PubMed Central

    Chi, Eric C.; Lange, Kenneth

    2014-01-01

    Estimation of a covariance matrix or its inverse plays a central role in many statistical methods. For these methods to work reliably, estimated matrices must not only be invertible but also well-conditioned. The current paper introduces a novel prior to ensure a well-conditioned maximum a posteriori (MAP) covariance estimate. The prior shrinks the sample covariance estimator towards a stable target and leads to a MAP estimator that is consistent and asymptotically efficient. Thus, the MAP estimator gracefully transitions towards the sample covariance matrix as the number of samples grows relative to the number of covariates. The utility of the MAP estimator is demonstrated in two standard applications – discriminant analysis and EM clustering – in this sampling regime. PMID:25143662

  1. Role of small-norm components in extended random-phase approximation

    NASA Astrophysics Data System (ADS)

    Tohyama, Mitsuru

    2017-09-01

    The role of the small-norm amplitudes in extended random-phase approximation (RPA) theories such as the particle-particle and hole-hole components of one-body amplitudes and the two-body amplitudes other than two-particle/two-hole components are investigated for the one-dimensional Hubbard model using an extended RPA derived from the time-dependent density matrix theory. It is found that these amplitudes cannot be neglected in strongly interacting regions where the effects of ground-state correlations are significant.

  2. Overview of NORM and activities by a NORM licensed permanent decontamination and waste processing facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mirro, G.A.

    1997-02-01

    This paper presents an overview of issues related to handling NORM materials, and provides a description of a facility designed for the processing of NORM contaminated equipment. With regard to handling NORM materials the author discusses sources of NORM, problems, regulations and disposal options, potential hazards, safety equipment, and issues related to personnel protection. For the facility, the author discusses: description of the permanent facility; the operations of the facility; the license it has for handling specific radioactive material; operating and safety procedures; decontamination facilities on site; NORM waste processing capabilities; and offsite NORM services which are available.

  3. Local social norms and military sexual stressors: do senior officers' norms matter?

    PubMed

    Murdoch, Maureen; Pryor, John Barron; Polusny, Melissa Anderson; Gackstetter, Gary D; Ripley, Diane Cowper

    2009-10-01

    To examine the relative importance of harassment-tolerant norms emanating from troops senior officers, immediate supervisors, and units on troops' sexual stressor experiences and to see whether associations differed by sex. Cross-sectional survey of all 681 willing and confirmed active duty troops enrolled in the VA National Enrollment Database between 1998 and 2002. Findings extended an earlier analysis. After adjusting for other significant correlates, senior officers' perceived tolerance of sexual harassment was not associated with the severity of sexual harassment troops reported (p = 0.64) or with the numbers of sexual identity challenges they reported (p = 0.11). Harassment-tolerant norms emanating from troops' units and immediate supervisors were associated with reporting more severe sexual harassment and more sexual identity challenges (all p < 0.003). Findings generalized across sex. Senior officers' norms did not appear to affect troops' reports of military sexual stressors, but unit norms and immediate supervisors' norms did.

  4. An improved nearly-orthogonal structured mesh generation system with smoothness control functions

    USDA-ARS?s Scientific Manuscript database

    This paper presents an improved nearly-orthogonal structured mesh generation system with a set of smoothness control functions, which were derived based on the ratio between the Jacobian of the transformation matrix and the Jacobian of the metric tensor. The proposed smoothness control functions are...

  5. Finite-time H∞ control for linear continuous system with norm-bounded disturbance

    NASA Astrophysics Data System (ADS)

    Meng, Qingyi; Shen, Yanjun

    2009-04-01

    In this paper, the definition of finite-time H∞ control is presented. The system under consideration is subject to time-varying norm-bounded exogenous disturbance. The main aim of this paper is focused on the design a state feedback controller which ensures that the closed-loop system is finite-time bounded (FTB) and reduces the effect of the disturbance input on the controlled output to a prescribed level. A sufficient condition is presented for the solvability of this problem, which can be reduced to a feasibility problem involving linear matrix inequalities (LMIs). A detailed solving method is proposed for the restricted linear matrix inequalities. Finally, examples are given to show the validity of the methodology.

  6. Peer Group Norms and Accountability Moderate the Effect of School Norms on Children's Intergroup Attitudes

    ERIC Educational Resources Information Center

    McGuire, Luke; Rutland, Adam; Nesdale, Drew

    2015-01-01

    The present study examined the interactive effects of school norms, peer norms, and accountability on children's intergroup attitudes. Participants (n = 229) aged 5-11 years, in a between-subjects design, were randomly assigned to a peer group with an inclusion or exclusion norm, learned their school either had an inclusion norm or not, and were…

  7. Weighted low-rank sparse model via nuclear norm minimization for bearing fault detection

    NASA Astrophysics Data System (ADS)

    Du, Zhaohui; Chen, Xuefeng; Zhang, Han; Yang, Boyuan; Zhai, Zhi; Yan, Ruqiang

    2017-07-01

    It is a fundamental task in the machine fault diagnosis community to detect impulsive signatures generated by the localized faults of bearings. The main goal of this paper is to exploit the low-rank physical structure of periodic impulsive features and further establish a weighted low-rank sparse model for bearing fault detection. The proposed model mainly consists of three basic components: an adaptive partition window, a nuclear norm regularization and a weighted sequence. Firstly, due to the periodic repetition mechanism of impulsive feature, an adaptive partition window could be designed to transform the impulsive feature into a data matrix. The highlight of partition window is to accumulate all local feature information and align them. Then, all columns of the data matrix share similar waveforms and a core physical phenomenon arises, i.e., these singular values of the data matrix demonstrates a sparse distribution pattern. Therefore, a nuclear norm regularization is enforced to capture that sparse prior. However, the nuclear norm regularization treats all singular values equally and thus ignores one basic fact that larger singular values have more information volume of impulsive features and should be preserved as much as possible. Therefore, a weighted sequence with adaptively tuning weights inversely proportional to singular amplitude is adopted to guarantee the distribution consistence of large singular values. On the other hand, the proposed model is difficult to solve due to its non-convexity and thus a new algorithm is developed to search one satisfying stationary solution through alternatively implementing one proximal operator operation and least-square fitting. Moreover, the sensitivity analysis and selection principles of algorithmic parameters are comprehensively investigated through a set of numerical experiments, which shows that the proposed method is robust and only has a few adjustable parameters. Lastly, the proposed model is applied to the

  8. Recovering hidden diagonal structures via non-negative matrix factorization with multiple constraints.

    PubMed

    Yang, Xi; Han, Guoqiang; Cai, Hongmin; Song, Yan

    2017-03-31

    Revealing data with intrinsically diagonal block structures is particularly useful for analyzing groups of highly correlated variables. Earlier researches based on non-negative matrix factorization (NMF) have been shown to be effective in representing such data by decomposing the observed data into two factors, where one factor is considered to be the feature and the other the expansion loading from a linear algebra perspective. If the data are sampled from multiple independent subspaces, the loading factor would possess a diagonal structure under an ideal matrix decomposition. However, the standard NMF method and its variants have not been reported to exploit this type of data via direct estimation. To address this issue, a non-negative matrix factorization with multiple constraints model is proposed in this paper. The constraints include an sparsity norm on the feature matrix and a total variational norm on each column of the loading matrix. The proposed model is shown to be capable of efficiently recovering diagonal block structures hidden in observed samples. An efficient numerical algorithm using the alternating direction method of multipliers model is proposed for optimizing the new model. Compared with several benchmark models, the proposed method performs robustly and effectively for simulated and real biological data.

  9. Arbitrary norm support vector machines.

    PubMed

    Huang, Kaizhu; Zheng, Danian; King, Irwin; Lyu, Michael R

    2009-02-01

    Support vector machines (SVM) are state-of-the-art classifiers. Typically L2-norm or L1-norm is adopted as a regularization term in SVMs, while other norm-based SVMs, for example, the L0-norm SVM or even the L(infinity)-norm SVM, are rarely seen in the literature. The major reason is that L0-norm describes a discontinuous and nonconvex term, leading to a combinatorially NP-hard optimization problem. In this letter, motivated by Bayesian learning, we propose a novel framework that can implement arbitrary norm-based SVMs in polynomial time. One significant feature of this framework is that only a sequence of sequential minimal optimization problems needs to be solved, thus making it practical in many real applications. The proposed framework is important in the sense that Bayesian priors can be efficiently plugged into most learning methods without knowing the explicit form. Hence, this builds a connection between Bayesian learning and the kernel machines. We derive the theoretical framework, demonstrate how our approach works on the L0-norm SVM as a typical example, and perform a series of experiments to validate its advantages. Experimental results on nine benchmark data sets are very encouraging. The implemented L0-norm is competitive with or even better than the standard L2-norm SVM in terms of accuracy but with a reduced number of support vectors, -9.46% of the number on average. When compared with another sparse model, the relevance vector machine, our proposed algorithm also demonstrates better sparse properties with a training speed over seven times faster.

  10. Injunctive social norms primacy over descriptive social norms in retirement savings decisions.

    PubMed

    Croy, Gerry; Gerrans, Paul; Speelman, Craig

    2010-01-01

    Consistent with the global trend to shift responsibility for retirement income provision from the public purse to individuals has been encouragement to save more and to manage investment strategy. Analyzing data from 2,300 respondents to a randomly distributed questionnaire, this article focuses on the motivational importance of social norms. The study finds injunctive social norms (what is commonly approved or disapproved of) exert greater influence than descriptive social norms (what is commonly done) in predicting retirement savings intentions. Modeling employs the theory of planned behavior, and also finds injunctive social norm has predictive primacy over attitude and perceived behavioral control. Discussion advocates a balanced approach to intervention design, and identifies opportunities for the further study of normative message framing.

  11. Methods of computing steady-state voltage stability margins of power systems

    DOEpatents

    Chow, Joe Hong; Ghiocel, Scott Gordon

    2018-03-20

    In steady-state voltage stability analysis, as load increases toward a maximum, conventional Newton-Raphson power flow Jacobian matrix becomes increasingly ill-conditioned so power flow fails to converge before reaching maximum loading. A method to directly eliminate this singularity reformulates the power flow problem by introducing an AQ bus with specified bus angle and reactive power consumption of a load bus. For steady-state voltage stability analysis, the angle separation between the swing bus and AQ bus can be varied to control power transfer to the load, rather than specifying the load power itself. For an AQ bus, the power flow formulation is only made up of a reactive power equation, thus reducing the size of the Jacobian matrix by one. This reduced Jacobian matrix is nonsingular at the critical voltage point, eliminating a major difficulty in voltage stability analysis for power system operations.

  12. Learning the Norm of Internality: NetNorm, a Connectionist Model

    ERIC Educational Resources Information Center

    Thierry, Bollon; Adeline, Paignon; Pascal, Pansu

    2011-01-01

    The objective of the present article is to show that connectionist simulations can be used to model some of the socio-cognitive processes underlying the learning of the norm of internality. For our simulations, we developed a connectionist model which we called NetNorm (based on Dual-Network formalism). This model is capable of simulating the…

  13. Convergence of Proximal Iteratively Reweighted Nuclear Norm Algorithm for Image Processing.

    PubMed

    Sun, Tao; Jiang, Hao; Cheng, Lizhi

    2017-08-25

    The nonsmooth and nonconvex regularization has many applications in imaging science and machine learning research due to its excellent recovery performance. A proximal iteratively reweighted nuclear norm algorithm has been proposed for the nonsmooth and nonconvex matrix minimizations. In this paper, we aim to investigate the convergence of the algorithm. With the Kurdyka-Łojasiewicz property, we prove the algorithm globally converges to a critical point of the objective function. The numerical results presented in this paper coincide with our theoretical findings.

  14. Using monolingual neuropsychological test norms with bilingual Hispanic americans: application of an individual comparison standard.

    PubMed

    Gasquoine, Philip Gerard; Gonzalez, Cassandra Dayanira

    2012-05-01

    Conventional neuropsychological norms developed for monolinguals likely overestimate normal performance in bilinguals on language but not visual-perceptual format tests. This was studied by comparing neuropsychological false-positive rates using the 50th percentile of conventional norms and individual comparison standards (Picture Vocabulary or Matrix Reasoning scores) as estimates of preexisting neuropsychological skill level against the number expected from the normal distribution for a consecutive sample of 56 neurologically intact, bilingual, Hispanic Americans. Participants were tested in separate sessions in Spanish and English in the counterbalanced order on La Bateria Neuropsicologica and the original English language tests on which this battery was based. For language format measures, repeated-measures multivariate analysis of variance showed that individual estimates of preexisting skill level in English generated the mean number of false positives most approximate to that expected from the normal distribution, whereas the 50th percentile of conventional English language norms did the same for visual-perceptual format measures. When using conventional Spanish or English monolingual norms for language format neuropsychological measures with bilingual Hispanic Americans, individual estimates of preexisting skill level are recommended over the 50th percentile.

  15. Computing sparse derivatives and consecutive zeros problem

    NASA Astrophysics Data System (ADS)

    Chandra, B. V. Ravi; Hossain, Shahadat

    2013-02-01

    We describe a substitution based sparse Jacobian matrix determination method using algorithmic differentiation. Utilizing the a priori known sparsity pattern, a compression scheme is determined using graph coloring. The "compressed pattern" of the Jacobian matrix is then reordered into a form suitable for computation by substitution. We show that the column reordering of the compressed pattern matrix (so as to align the zero entries into consecutive locations in each row) can be viewed as a variant of traveling salesman problem. Preliminary computational results show that on the test problems the performance of nearest-neighbor type heuristic algorithms is highly encouraging.

  16. Two conditions for equivalence of 0-norm solution and 1-norm solution in sparse representation.

    PubMed

    Li, Yuanqing; Amari, Shun-Ichi

    2010-07-01

    In sparse representation, two important sparse solutions, the 0-norm and 1-norm solutions, have been receiving much of attention. The 0-norm solution is the sparsest, however it is not easy to obtain. Although the 1-norm solution may not be the sparsest, it can be easily obtained by the linear programming method. In many cases, the 0-norm solution can be obtained through finding the 1-norm solution. Many discussions exist on the equivalence of the two sparse solutions. This paper analyzes two conditions for the equivalence of the two sparse solutions. The first condition is necessary and sufficient, however, difficult to verify. Although the second is necessary but is not sufficient, it is easy to verify. In this paper, we analyze the second condition within the stochastic framework and propose a variant. We then prove that the equivalence of the two sparse solutions holds with high probability under the variant of the second condition. Furthermore, in the limit case where the 0-norm solution is extremely sparse, the second condition is also a sufficient condition with probability 1.

  17. Rank-Optimized Logistic Matrix Regression toward Improved Matrix Data Classification.

    PubMed

    Zhang, Jianguang; Jiang, Jianmin

    2018-02-01

    While existing logistic regression suffers from overfitting and often fails in considering structural information, we propose a novel matrix-based logistic regression to overcome the weakness. In the proposed method, 2D matrices are directly used to learn two groups of parameter vectors along each dimension without vectorization, which allows the proposed method to fully exploit the underlying structural information embedded inside the 2D matrices. Further, we add a joint [Formula: see text]-norm on two parameter matrices, which are organized by aligning each group of parameter vectors in columns. This added co-regularization term has two roles-enhancing the effect of regularization and optimizing the rank during the learning process. With our proposed fast iterative solution, we carried out extensive experiments. The results show that in comparison to both the traditional tensor-based methods and the vector-based regression methods, our proposed solution achieves better performance for matrix data classifications.

  18. Dutch taboo norms.

    PubMed

    Roest, Sander A; Visser, Tessa A; Zeelenberg, René

    2018-04-01

    This article provides norms for general taboo, personal taboo, insult, valence, and arousal for 672 Dutch words, including 202 taboo words. Norms were collected using a 7-point Likert scale and based on ratings by psychology students from the Erasmus University Rotterdam in The Netherlands. The sample consisted of 87 psychology students (58 females, 29 males). We obtained high reliability based on split-half analyses. Our norms show high correlations with arousal and valence ratings collected by another Dutch word-norms study (Moors et al.,, Behavior Research Methods, 45, 169-177, 2013). Our results show that the previously found quadratic relation (i.e., U-shaped pattern) between valence and arousal also holds when only taboo words are considered. Additionally, words rated high on taboo tended to be rated low on valence, but some words related to sex rated high on both taboo and valence. Words that rated high on taboo rated high on insult, again with the exception of words related to sex many of which rated low on insult. Finally, words rated high on taboo and insult rated high on arousal. The Dutch Taboo Norms (DTN) database is a useful tool for researchers interested in the effects of taboo words on cognitive processing. The data associated with this paper can be accessed via the Open Science Framework ( https://osf.io/vk782/ ).

  19. What's in a norm? Sources and processes of norm change.

    PubMed

    Paluck, Elizabeth Levy

    2009-03-01

    This reply to the commentary by E. Staub and L. A. Pearlman (2009) revisits the field experimental results of E. L. Paluck (2009). It introduces further evidence and theoretical elaboration supporting Paluck's conclusion that exposure to a reconciliation-themed radio soap opera changed perceptions of social norms and behaviors, not beliefs. Experimental and longitudinal survey evidence reinforces the finding that the radio program affected socially shared perceptions of typical or prescribed behavior-that is, social norms. Specifically, measurements of perceptions of social norms called into question by Staub and Pearlman are shown to correlate with perceptions of public opinion and public, not private, behaviors. Although measurement issues and the mechanisms of the radio program's influence merit further testing, theory and evidence point to social interactions and emotional engagement, not individual education, as the likely mechanisms of change. The present exchange makes salient what is at stake in this debate: a model of change based on learning and personal beliefs versus a model based on group influence and social norms. These theoretical models recommend very different strategies for prejudice and conflict reduction. Future field experiments should attempt to adjudicate between these models by testing relevant policies in real-world settings.

  20. Global Norms: Towards Some Guidelines for Aggregating Personality Norms across Countries

    ERIC Educational Resources Information Center

    Bartram, Dave

    2008-01-01

    The article discusses issues relating to the international use of personality inventories, especially those in which organizations make comparisons between people from differing cultures or countries or those with different languages. The focus is on the issue of norming and the use of national versus multinational norms. It is noted that…

  1. Non-Abelian integrable hierarchies: matrix biorthogonal polynomials and perturbations

    NASA Astrophysics Data System (ADS)

    Ariznabarreta, Gerardo; García-Ardila, Juan C.; Mañas, Manuel; Marcellán, Francisco

    2018-05-01

    In this paper, Geronimus–Uvarov perturbations for matrix orthogonal polynomials on the real line are studied and then applied to the analysis of non-Abelian integrable hierarchies. The orthogonality is understood in full generality, i.e. in terms of a nondegenerate continuous sesquilinear form, determined by a quasidefinite matrix of bivariate generalized functions with a well-defined support. We derive Christoffel-type formulas that give the perturbed matrix biorthogonal polynomials and their norms in terms of the original ones. The keystone for this finding is the Gauss–Borel factorization of the Gram matrix. Geronimus–Uvarov transformations are considered in the context of the 2D non-Abelian Toda lattice and noncommutative KP hierarchies. The interplay between transformations and integrable flows is discussed. Miwa shifts, τ-ratio matrix functions and Sato formulas are given. Bilinear identities, involving Geronimus–Uvarov transformations, first for the Baker functions, then secondly for the biorthogonal polynomials and its second kind functions, and finally for the τ-ratio matrix functions, are found.

  2. Children are sensitive to norms of giving.

    PubMed

    McAuliffe, Katherine; Raihani, Nichola J; Dunham, Yarrow

    2017-10-01

    People across societies engage in costly sharing, but the extent of such sharing shows striking cultural variation, highlighting the importance of local norms in shaping generosity. Despite this acknowledged role for norms, it is unclear when they begin to exert their influence in development. Here we use a Dictator Game to investigate the extent to which 4- to 9-year-old children are sensitive to selfish (give 20%) and generous (give 80%) norms. Additionally, we varied whether children were told how much other children give (descriptive norm) or what they should give according to an adult (injunctive norm). Results showed that children generally gave more when they were exposed to a generous norm. However, patterns of compliance varied with age. Younger children were more likely to comply with the selfish norm, suggesting a licensing effect. By contrast, older children were more influenced by the generous norm, yet capped their donations at 50%, perhaps adhering to a pre-existing norm of equality. Children were not differentially influenced by descriptive or injunctive norms, suggesting a primacy of norm content over norm format. Together, our findings indicate that while generosity is malleable in children, normative information does not completely override pre-existing biases. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A Handful of Paragraphs on "Translation" and "Norms."

    ERIC Educational Resources Information Center

    Toury, Gideon

    1998-01-01

    Presents some thoughts on the issue of translation and norms, focusing on the relationships between social agreements, conventions, and norms; translational norms; acts of translation and translation events; norms and values; norms for translated texts versus norms for non-translated texts; and competing norms. Comments on the reactions to three…

  4. Social norms and prejudice against homosexuals.

    PubMed

    Pereira, Annelyse; Monteiro, Maria Benedicta; Camino, Leoncio

    2009-11-01

    Different studies regarding the role of norms on the expression of prejudice have shown that the anti-prejudice norm influences people to inhibit prejudice expressions. However, if norm pressure has led to a substantial decrease in the public expression of prejudice against certain targets (e.g., blacks, women, blind people), little theoretical and empirical attention has been paid to the role of this general norm regarding sexual minorities (e.g., prostitutes, lesbians and gays). In this sense, the issue we want to address is whether general anti-prejudice norms can reduce the expression of prejudice against homosexual individuals. In this research we investigate the effect of activating an anti-prejudice norm against homosexuals on blatant and subtle expressions of prejudice. The anti-prejudice norm was experimentally manipulated and its effects were observed on rejection to intimacy (blatant prejudice) and on positive-negative emotions (subtle prejudice) regarding homosexuals. 136 university students were randomly allocated to activated-norm and control conditions and completed a questionnaire that included norm manipulation and the dependent variables. A multivariate analysis of variance (MANOVA) as well as subsequent ANOVAS showed that only in the high normative pressure condition participants expressed less rejection to intimacy and less negative emotions against homosexuals, when compared to the simple norm-activation and the control conditions. Positive emotions, however, were similar both in the high normative pressure and the control conditions. We concluded that a high anti-prejudice pressure regarding homosexuals could reduce blatant prejudice but not subtle prejudice, considering that the expression of negative emotions decreased while the expression of positive emotions remained stable.

  5. Conditional random matrix ensembles and the stability of dynamical systems

    NASA Astrophysics Data System (ADS)

    Kirk, Paul; Rolando, Delphine M. Y.; MacLean, Adam L.; Stumpf, Michael P. H.

    2015-08-01

    Random matrix theory (RMT) has found applications throughout physics and applied mathematics, in subject areas as diverse as communications networks, population dynamics, neuroscience, and models of the banking system. Many of these analyses exploit elegant analytical results, particularly the circular law and its extensions. In order to apply these results, assumptions must be made about the distribution of matrix elements. Here we demonstrate that the choice of matrix distribution is crucial. In particular, adopting an unrealistic matrix distribution for the sake of analytical tractability is liable to lead to misleading conclusions. We focus on the application of RMT to the long-standing, and at times fractious, ‘diversity-stability debate’, which is concerned with establishing whether large complex systems are likely to be stable. Early work (and subsequent elaborations) brought RMT to bear on the debate by modelling the entries of a system’s Jacobian matrix as independent and identically distributed (i.i.d.) random variables. These analyses were successful in yielding general results that were not tied to any specific system, but relied upon a restrictive i.i.d. assumption. Other studies took an opposing approach, seeking to elucidate general principles of stability through the analysis of specific systems. Here we develop a statistical framework that reconciles these two contrasting approaches. We use a range of illustrative dynamical systems examples to demonstrate that: (i) stability probability cannot be summarily deduced from any single property of the system (e.g. its diversity); and (ii) our assessment of stability depends on adequately capturing the details of the systems analysed. Failing to condition on the structure of dynamical systems will skew our analysis and can, even for very small systems, result in an unnecessarily pessimistic diagnosis of their stability.

  6. Jacobian projection reduced-order models for dynamic systems with contact nonlinearities

    NASA Astrophysics Data System (ADS)

    Gastaldi, Chiara; Zucca, Stefano; Epureanu, Bogdan I.

    2018-02-01

    In structural dynamics, the prediction of the response of systems with localized nonlinearities, such as friction dampers, is of particular interest. This task becomes especially cumbersome when high-resolution finite element models are used. While state-of-the-art techniques such as Craig-Bampton component mode synthesis are employed to generate reduced order models, the interface (nonlinear) degrees of freedom must still be solved in-full. For this reason, a new generation of specialized techniques capable of reducing linear and nonlinear degrees of freedom alike is emerging. This paper proposes a new technique that exploits spatial correlations in the dynamics to compute a reduction basis. The basis is composed of a set of vectors obtained using the Jacobian of partial derivatives of the contact forces with respect to nodal displacements. These basis vectors correspond to specifically chosen boundary conditions at the contacts over one cycle of vibration. The technique is shown to be effective in the reduction of several models studied using multiple harmonics with a coupled static solution. In addition, this paper addresses another challenge common to all reduction techniques: it presents and validates a novel a posteriori error estimate capable of evaluating the quality of the reduced-order solution without involving a comparison with the full-order solution.

  7. Implicit Plasma Kinetic Simulation Using The Jacobian-Free Newton-Krylov Method

    NASA Astrophysics Data System (ADS)

    Taitano, William; Knoll, Dana; Chacon, Luis

    2009-11-01

    The use of fully implicit time integration methods in kinetic simulation is still area of algorithmic research. A brute-force approach to simultaneously including the field equations and the particle distribution function would result in an intractable linear algebra problem. A number of algorithms have been put forward which rely on an extrapolation in time. They can be thought of as linearly implicit methods or one-step Newton methods. However, issues related to time accuracy of these methods still remain. We are pursuing a route to implicit plasma kinetic simulation which eliminates extrapolation, eliminates phase-space from the linear algebra problem, and converges the entire nonlinear system within a time step. We accomplish all this using the Jacobian-Free Newton-Krylov algorithm. The original research along these lines considered particle methods to advance the distribution function [1]. In the current research we are advancing the Vlasov equations on a grid. Results will be presented which highlight algorithmic details for single species electrostatic problems and coupled ion-electron electrostatic problems. [4pt] [1] H. J. Kim, L. Chac'on, G. Lapenta, ``Fully implicit particle in cell algorithm,'' 47th Annual Meeting of the Division of Plasma Physics, Oct. 24-28, 2005, Denver, CO

  8. Social norms and their influence on eating behaviours.

    PubMed

    Higgs, Suzanne

    2015-03-01

    Social norms are implicit codes of conduct that provide a guide to appropriate action. There is ample evidence that social norms about eating have a powerful effect on both food choice and amounts consumed. This review explores the reasons why people follow social eating norms and the factors that moderate norm following. It is proposed that eating norms are followed because they provide information about safe foods and facilitate food sharing. Norms are a powerful influence on behaviour because following (or not following) norms is associated with social judgements. Norm following is more likely when there is uncertainty about what constitutes correct behaviour and when there is greater shared identity with the norm referent group. Social norms may affect food choice and intake by altering self-perceptions and/or by altering the sensory/hedonic evaluation of foods. The same neural systems that mediate the rewarding effects of food itself are likely to reinforce the following of eating norms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. A contracting-interval program for the Danilewski method. Ph.D. Thesis - Va. Univ.

    NASA Technical Reports Server (NTRS)

    Harris, J. D.

    1971-01-01

    The concept of contracting-interval programs is applied to finding the eigenvalues of a matrix. The development is a three-step process in which (1) a program is developed for the reduction of a matrix to Hessenberg form, (2) a program is developed for the reduction of a Hessenberg matrix to colleague form, and (3) the characteristic polynomial with interval coefficients is readily obtained from the interval of colleague matrices. This interval polynomial is then factored into quadratic factors so that the eigenvalues may be obtained. To develop a contracting-interval program for factoring this polynomial with interval coefficients it is necessary to have an iteration method which converges even in the presence of controlled rounding errors. A theorem is stated giving sufficient conditions for the convergence of Newton's method when both the function and its Jacobian cannot be evaluated exactly but errors can be made proportional to the square of the norm of the difference between the previous two iterates. This theorem is applied to prove the convergence of the generalization of the Newton-Bairstow method that is used to obtain quadratic factors of the characteristic polynomial.

  10. Joint Smoothed l₀-Norm DOA Estimation Algorithm for Multiple Measurement Vectors in MIMO Radar.

    PubMed

    Liu, Jing; Zhou, Weidong; Juwono, Filbert H

    2017-05-08

    Direction-of-arrival (DOA) estimation is usually confronted with a multiple measurement vector (MMV) case. In this paper, a novel fast sparse DOA estimation algorithm, named the joint smoothed l 0 -norm algorithm, is proposed for multiple measurement vectors in multiple-input multiple-output (MIMO) radar. To eliminate the white or colored Gaussian noises, the new method first obtains a low-complexity high-order cumulants based data matrix. Then, the proposed algorithm designs a joint smoothed function tailored for the MMV case, based on which joint smoothed l 0 -norm sparse representation framework is constructed. Finally, for the MMV-based joint smoothed function, the corresponding gradient-based sparse signal reconstruction is designed, thus the DOA estimation can be achieved. The proposed method is a fast sparse representation algorithm, which can solve the MMV problem and perform well for both white and colored Gaussian noises. The proposed joint algorithm is about two orders of magnitude faster than the l 1 -norm minimization based methods, such as l 1 -SVD (singular value decomposition), RV (real-valued) l 1 -SVD and RV l 1 -SRACV (sparse representation array covariance vectors), and achieves better DOA estimation performance.

  11. Professional Norms Guiding School Principals' Pedagogical Leadership

    ERIC Educational Resources Information Center

    Leo, Ulf

    2015-01-01

    Purpose: The purpose of this paper is to identify and analyze the professional norms surrounding school development, with a special emphasis on school principals' pedagogical leadership. Design/methodology/approach: A norm perspective is used to identify possible links between legal norms, professional norms, and actions. The findings are based on…

  12. The Effects of Liking Norms and Descriptive Norms on Vegetable Consumption: A Randomized Experiment

    PubMed Central

    Thomas, Jason M.; Liu, Jinyu; Robinson, Eric L.; Aveyard, Paul; Herman, C. Peter; Higgs, Suzanne

    2016-01-01

    There is evidence that social norm messages can be used to promote the selection of fruit and vegetables in low habitual consumers of these foods but it is unclear whether this effect is sustained over time. It is also unclear whether information about others' liking for a food (liking norm) could have the same effect. Using a 2 × 5 × 2 experimental design we investigated the effects of exposure to various messages on later intake from a food buffet and whether any effects were sustained 24 h after exposure in both low and high consumers of vegetables. There were three factors: delay (immediate food selection vs. food selection 24 h after exposure), message type (liking norm, descriptive norm, health message, vegetable variety condition, and neutral control message), and habitual consumption (low vs. high). The buffet consisted of three raw vegetables, three energy-dense foods, and two dips. For vegetables and non-vegetables there were no main effects of message type, nor any main effect of delay. There was a significant message × habitual vegetable consumption interaction for vegetable consumption; however, follow up tests did not yield any significant effects. Examining each food individually, there were no main effects of message type, nor any main effect of delay, for any of the foods; however, there was a message × habitual vegetable consumption interaction for broccoli. Consumption of broccoli in the health message and descriptive norm conditions did not differ from the control neutral condition. However, habitually low consumers of vegetables increased their consumption of broccoli in the vegetable variety and liking norm conditions relative to habitual low vegetable consumers in the neutral control condition (p < 0.05). Further, investigation of the effects of the liking norm and vegetable variety condition on vegetable intake is warranted. This trial is listed as NCT02618174 at clinicaltrials.gov. PMID:27065913

  13. Convex Banding of the Covariance Matrix.

    PubMed

    Bien, Jacob; Bunea, Florentina; Xiao, Luo

    2016-01-01

    We introduce a new sparse estimator of the covariance matrix for high-dimensional models in which the variables have a known ordering. Our estimator, which is the solution to a convex optimization problem, is equivalently expressed as an estimator which tapers the sample covariance matrix by a Toeplitz, sparsely-banded, data-adaptive matrix. As a result of this adaptivity, the convex banding estimator enjoys theoretical optimality properties not attained by previous banding or tapered estimators. In particular, our convex banding estimator is minimax rate adaptive in Frobenius and operator norms, up to log factors, over commonly-studied classes of covariance matrices, and over more general classes. Furthermore, it correctly recovers the bandwidth when the true covariance is exactly banded. Our convex formulation admits a simple and efficient algorithm. Empirical studies demonstrate its practical effectiveness and illustrate that our exactly-banded estimator works well even when the true covariance matrix is only close to a banded matrix, confirming our theoretical results. Our method compares favorably with all existing methods, in terms of accuracy and speed. We illustrate the practical merits of the convex banding estimator by showing that it can be used to improve the performance of discriminant analysis for classifying sound recordings.

  14. Convex Banding of the Covariance Matrix

    PubMed Central

    Bien, Jacob; Bunea, Florentina; Xiao, Luo

    2016-01-01

    We introduce a new sparse estimator of the covariance matrix for high-dimensional models in which the variables have a known ordering. Our estimator, which is the solution to a convex optimization problem, is equivalently expressed as an estimator which tapers the sample covariance matrix by a Toeplitz, sparsely-banded, data-adaptive matrix. As a result of this adaptivity, the convex banding estimator enjoys theoretical optimality properties not attained by previous banding or tapered estimators. In particular, our convex banding estimator is minimax rate adaptive in Frobenius and operator norms, up to log factors, over commonly-studied classes of covariance matrices, and over more general classes. Furthermore, it correctly recovers the bandwidth when the true covariance is exactly banded. Our convex formulation admits a simple and efficient algorithm. Empirical studies demonstrate its practical effectiveness and illustrate that our exactly-banded estimator works well even when the true covariance matrix is only close to a banded matrix, confirming our theoretical results. Our method compares favorably with all existing methods, in terms of accuracy and speed. We illustrate the practical merits of the convex banding estimator by showing that it can be used to improve the performance of discriminant analysis for classifying sound recordings. PMID:28042189

  15. NORM Management in the Oil & Gas Industry

    NASA Astrophysics Data System (ADS)

    Cowie, Michael; Mously, Khalid; Fageeha, Osama; Nassar, Rafat

    2008-08-01

    It has been established that Naturally Occurring Radioactive Materials (NORM) accumulates at various locations along the oil/gas production process. Components such as wellheads, separation vessels, pumps, and other processing equipment can become NORM contaminated, and NORM can accumulate in sludge and other waste media. Improper handling and disposal of NORM contaminated equipment and waste can create a potential radiation hazard to workers and the environment. Saudi Aramco Environmental Protection Department initiated a program to identify the extent, form and level of NORM contamination associated with the company operations. Once identified the challenge of managing operations which had a NORM hazard was addressed in a manner that gave due consideration to workers and environmental protection as well as operations' efficiency and productivity. The benefits of shared knowledge, practice and experience across the oil & gas industry are seen as key to the establishment of common guidance on NORM management. This paper outlines Saudi Aramco's experience in the development of a NORM management strategy and its goals of establishing common guidance throughout the oil and gas industry.

  16. Injunctive Norms and Alcohol Consumption: A Revised Conceptualization

    PubMed Central

    Krieger, Heather; Neighbors, Clayton; Lewis, Melissa A.; LaBrie, Joseph W.; Foster, Dawn W.; Larimer, Mary E.

    2016-01-01

    Background Injunctive norms have been found to be important predictors of behaviors in many disciplines with the exception of alcohol research. This exception is likely due to a misconceptualization of injunctive norms for alcohol consumption. To address this, we outline and test a new conceptualization of injunctive norms and personal approval for alcohol consumption. Traditionally, injunctive norms have been assessed using Likert scale ratings of approval perceptions, whereas descriptive norms and individual behaviors are typically measured with behavioral estimates (i.e., number of drinks consumed per week, frequency of drinking, etc.). This makes comparisons between these constructs difficult because they are not similar conceptualizations of drinking behaviors. The present research evaluated a new representation of injunctive norms with anchors comparable to descriptive norms measures. Methods A study and a replication were conducted including 2,559 and 1,189 undergraduate students from three different universities. Participants reported on their alcohol-related consumption behaviors, personal approval of drinking, and descriptive and injunctive norms. Personal approval and injunctive norms were measured using both traditional measures and a new drink-based measure. Results Results from both studies indicated that drink-based injunctive norms were uniquely and positively associated with drinking whereas traditionally assessed injunctive norms were negatively associated with drinking. Analyses also revealed significant unique associations between drink-based injunctive norms and personal approval when controlling for descriptive norms. Conclusions These findings provide support for a modified conceptualization of personal approval and injunctive norms related to alcohol consumption and, importantly, offers an explanation and practical solution for the small and inconsistent findings related to injunctive norms and drinking in past studies. PMID:27030295

  17. Hessian-based norm regularization for image restoration with biomedical applications.

    PubMed

    Lefkimmiatis, Stamatios; Bourquard, Aurélien; Unser, Michael

    2012-03-01

    We present nonquadratic Hessian-based regularization methods that can be effectively used for image restoration problems in a variational framework. Motivated by the great success of the total-variation (TV) functional, we extend it to also include second-order differential operators. Specifically, we derive second-order regularizers that involve matrix norms of the Hessian operator. The definition of these functionals is based on an alternative interpretation of TV that relies on mixed norms of directional derivatives. We show that the resulting regularizers retain some of the most favorable properties of TV, i.e., convexity, homogeneity, rotation, and translation invariance, while dealing effectively with the staircase effect. We further develop an efficient minimization scheme for the corresponding objective functions. The proposed algorithm is of the iteratively reweighted least-square type and results from a majorization-minimization approach. It relies on a problem-specific preconditioned conjugate gradient method, which makes the overall minimization scheme very attractive since it can be applied effectively to large images in a reasonable computational time. We validate the overall proposed regularization framework through deblurring experiments under additive Gaussian noise on standard and biomedical images.

  18. System identification using Nuclear Norm & Tabu Search optimization

    NASA Astrophysics Data System (ADS)

    Ahmed, Asif A.; Schoen, Marco P.; Bosworth, Ken W.

    2018-01-01

    In recent years, subspace System Identification (SI) algorithms have seen increased research, stemming from advanced minimization methods being applied to the Nuclear Norm (NN) approach in system identification. These minimization algorithms are based on hard computing methodologies. To the authors’ knowledge, as of now, there has been no work reported that utilizes soft computing algorithms to address the minimization problem within the nuclear norm SI framework. A linear, time-invariant, discrete time system is used in this work as the basic model for characterizing a dynamical system to be identified. The main objective is to extract a mathematical model from collected experimental input-output data. Hankel matrices are constructed from experimental data, and the extended observability matrix is employed to define an estimated output of the system. This estimated output and the actual - measured - output are utilized to construct a minimization problem. An embedded rank measure assures minimum state realization outcomes. Current NN-SI algorithms employ hard computing algorithms for minimization. In this work, we propose a simple Tabu Search (TS) algorithm for minimization. TS algorithm based SI is compared with the iterative Alternating Direction Method of Multipliers (ADMM) line search optimization based NN-SI. For comparison, several different benchmark system identification problems are solved by both approaches. Results show improved performance of the proposed SI-TS algorithm compared to the NN-SI ADMM algorithm.

  19. High-dimensional statistical inference: From vector to matrix

    NASA Astrophysics Data System (ADS)

    Zhang, Anru

    Statistical inference for sparse signals or low-rank matrices in high-dimensional settings is of significant interest in a range of contemporary applications. It has attracted significant recent attention in many fields including statistics, applied mathematics and electrical engineering. In this thesis, we consider several problems in including sparse signal recovery (compressed sensing under restricted isometry) and low-rank matrix recovery (matrix recovery via rank-one projections and structured matrix completion). The first part of the thesis discusses compressed sensing and affine rank minimization in both noiseless and noisy cases and establishes sharp restricted isometry conditions for sparse signal and low-rank matrix recovery. The analysis relies on a key technical tool which represents points in a polytope by convex combinations of sparse vectors. The technique is elementary while leads to sharp results. It is shown that, in compressed sensing, delta kA < 1/3, deltak A+ thetak,kA < 1, or deltatkA < √( t - 1)/t for any given constant t ≥ 4/3 guarantee the exact recovery of all k sparse signals in the noiseless case through the constrained ℓ1 minimization, and similarly in affine rank minimization delta rM < 1/3, deltar M + thetar, rM < 1, or deltatrM< √( t - 1)/t ensure the exact reconstruction of all matrices with rank at most r in the noiseless case via the constrained nuclear norm minimization. Moreover, for any epsilon > 0, delta kA < 1/3 + epsilon, deltak A + thetak,kA < 1 + epsilon, or deltatkA< √(t - 1) / t + epsilon are not sufficient to guarantee the exact recovery of all k-sparse signals for large k. Similar result also holds for matrix recovery. In addition, the conditions delta kA<1/3, deltak A+ thetak,kA<1, delta tkA < √(t - 1)/t and deltarM<1/3, delta rM+ thetar,rM<1, delta trM< √(t - 1)/ t are also shown to be sufficient respectively for stable recovery of approximately sparse signals and low-rank matrices in the noisy case

  20. Robust Image Regression Based on the Extended Matrix Variate Power Exponential Distribution of Dependent Noise.

    PubMed

    Luo, Lei; Yang, Jian; Qian, Jianjun; Tai, Ying; Lu, Gui-Fu

    2017-09-01

    Dealing with partial occlusion or illumination is one of the most challenging problems in image representation and classification. In this problem, the characterization of the representation error plays a crucial role. In most current approaches, the error matrix needs to be stretched into a vector and each element is assumed to be independently corrupted. This ignores the dependence between the elements of error. In this paper, it is assumed that the error image caused by partial occlusion or illumination changes is a random matrix variate and follows the extended matrix variate power exponential distribution. This has the heavy tailed regions and can be used to describe a matrix pattern of l×m dimensional observations that are not independent. This paper reveals the essence of the proposed distribution: it actually alleviates the correlations between pixels in an error matrix E and makes E approximately Gaussian. On the basis of this distribution, we derive a Schatten p -norm-based matrix regression model with L q regularization. Alternating direction method of multipliers is applied to solve this model. To get a closed-form solution in each step of the algorithm, two singular value function thresholding operators are introduced. In addition, the extended Schatten p -norm is utilized to characterize the distance between the test samples and classes in the design of the classifier. Extensive experimental results for image reconstruction and classification with structural noise demonstrate that the proposed algorithm works much more robustly than some existing regression-based methods.

  1. Impact of Norm Perceptions and Guilt on Audience Response to Anti-Smoking Norm PSAs: The Case of Korean Male Smokers

    ERIC Educational Resources Information Center

    Lee, Hyegyu; Paek, Hye-Jin

    2013-01-01

    Objective: To examine how norm appeals and guilt influence smokers' behavioural intention. Design: Quasi-experimental design. Setting: South Korea. Method: Two hundred and fifty-five male smokers were randomly assigned to descriptive, injunctive, or subjective anti-smoking norm messages. After they viewed the norm messages, their norm perceptions,…

  2. NORM regulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gray, P.

    1997-02-01

    The author reviews the question of regulation for naturally occuring radioactive material (NORM), and the factors that have made this a more prominent concern today. Past practices have been very relaxed, and have often involved very poor records, the involvment of contractors, and the disposition of contaminated equipment back into commercial service. The rationale behind the establishment of regulations is to provide worker protection, to exempt low risk materials, to aid in scrap recycling, to provide direction for remediation and to examine disposal options. The author reviews existing regulations at federal and state levels, impending legislation, and touches on themore » issue of site remediation and potential liabilities affecting the release of sites contaminated by NORM.« less

  3. NORM management in the oil and gas industry.

    PubMed

    Cowie, M; Mously, K; Fageeha, O; Nassar, R

    2012-01-01

    It has been established that naturally occurring radioactive material (NORM) may accumulate at various locations along the oil and gas production process. Components such as wellheads, separation vessels, pumps, and other processing equipment can become contaminated with NORM, and NORM can accumulate in the form of sludge, scale, scrapings, and other waste media. This can create a potential radiation hazard to workers, the general public, and the environment if certain controls are not established. Saudi Aramco has developed NORM management guidelines, and is implementing a comprehensive strategy to address all aspects of NORM management that aim to enhance NORM monitoring; control of NORM-contaminated equipment; control of NORM waste handling and disposal; and protection, awareness, and training of workers. The benefits of shared knowledge, best practice, and experience across the oil and gas industry are seen as key to the establishment of common guidance. This paper outlines Saudi Aramco's experience in the development of a NORM management strategy, and its goals of establishing common guidance throughout the oil and gas industry. Copyright © 2012. Published by Elsevier Ltd.

  4. How do social norms influence prosocial development?

    PubMed

    House, Bailey R

    2018-04-01

    Humans are both highly prosocial and extremely sensitive to social norms, and some theories suggest that norms are necessary to account for uniquely human forms of prosocial behavior and cooperation. Understanding how norms influence prosocial behavior is thus essential if we are to describe the psychology and development of prosocial behavior. In this article I review recent research from across the social sciences that provides (1) a theoretical model of how norms influence prosocial behavior, (2) empirical support for the model based on studies with adults and children, and (3) predictions about the psychological mechanisms through which norms shape prosocial behavior. I conclude by discussing the need for future studies into how prosocial behavior develops through emerging interactions between culturally varying norms, social cognition, emotions, and potentially genes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Naturally Occurring Radioactive Materials (NORM)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gray, P.

    1997-02-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards theymore » present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training).« less

  6. Perceptual dehumanization of faces is activated by norm violations and facilitates norm enforcement.

    PubMed

    Fincher, Katrina M; Tetlock, Philip E

    2016-02-01

    This article uses methods drawn from perceptual psychology to answer a basic social psychological question: Do people process the faces of norm violators differently from those of others--and, if so, what is the functional significance? Seven studies suggest that people process these faces different and the differential processing makes it easier to punish norm violators. Studies 1 and 2 use a recognition-recall paradigm that manipulated facial-inversion and spatial frequency to show that people rely upon face-typical processing less when they perceive norm violators' faces. Study 3 uses a facial composite task to demonstrate that the effect is actor dependent, not action dependent, and to suggest that configural processing is the mechanism of perceptual change. Studies 4 and 5 use offset faces to show that configural processing is only attenuated when they belong to perpetrators who are culpable. Studies 6 and 7 show that people find it easier to punish inverted faces and harder to punish faces displayed in low spatial frequency. Taken together, these data suggest a bidirectional flow of causality between lower-order perceptual and higher-order cognitive processes in norm enforcement. PsycINFO Database Record (c) 2016 APA, all rights reserved.

  7. An Abbreviated Tool for Assessing Feminine Norm Conformity: Psychometric Properties of the Conformity to Feminine Norms Inventory-45

    ERIC Educational Resources Information Center

    Parent, Mike C.; Moradi, Bonnie

    2011-01-01

    The Conformity to Feminine Norms Inventory-45 (CFNI-45; Parent & Moradi, 2010) is an important tool for assessing level of conformity to feminine gender norms and for investigating the implications of such norms for women's functioning. The authors of the present study assessed the factor structure, measurement invariance, reliability, and…

  8. A Review of Norms and Normative Multiagent Systems

    PubMed Central

    Mahmoud, Moamin A.; Ahmad, Mohd Sharifuddin; Mustapha, Aida

    2014-01-01

    Norms and normative multiagent systems have become the subjects of interest for many researchers. Such interest is caused by the need for agents to exploit the norms in enhancing their performance in a community. The term norm is used to characterize the behaviours of community members. The concept of normative multiagent systems is used to facilitate collaboration and coordination among social groups of agents. Many researches have been conducted on norms that investigate the fundamental concepts, definitions, classification, and types of norms and normative multiagent systems including normative architectures and normative processes. However, very few researches have been found to comprehensively study and analyze the literature in advancing the current state of norms and normative multiagent systems. Consequently, this paper attempts to present the current state of research on norms and normative multiagent systems and propose a norm's life cycle model based on the review of the literature. Subsequently, this paper highlights the significant areas for future work. PMID:25110739

  9. Covariance expressions for eigenvalue and eigenvector problems

    NASA Astrophysics Data System (ADS)

    Liounis, Andrew J.

    There are a number of important scientific and engineering problems whose solutions take the form of an eigenvalue--eigenvector problem. Some notable examples include solutions to linear systems of ordinary differential equations, controllability of linear systems, finite element analysis, chemical kinetics, fitting ellipses to noisy data, and optimal estimation of attitude from unit vectors. In many of these problems, having knowledge of the eigenvalue and eigenvector Jacobians is either necessary or is nearly as important as having the solution itself. For instance, Jacobians are necessary to find the uncertainty in a computed eigenvalue or eigenvector estimate. This uncertainty, which is usually represented as a covariance matrix, has been well studied for problems similar to the eigenvalue and eigenvector problem, such as singular value decomposition. There has been substantially less research on the covariance of an optimal estimate originating from an eigenvalue-eigenvector problem. In this thesis we develop two general expressions for the Jacobians of eigenvalues and eigenvectors with respect to the elements of their parent matrix. The expressions developed make use of only the parent matrix and the eigenvalue and eigenvector pair under consideration. In addition, they are applicable to any general matrix (including complex valued matrices, eigenvalues, and eigenvectors) as long as the eigenvalues are simple. Alongside this, we develop expressions that determine the uncertainty in a vector estimate obtained from an eigenvalue-eigenvector problem given the uncertainty of the terms of the matrix. The Jacobian expressions developed are numerically validated with forward finite, differencing and the covariance expressions are validated using Monte Carlo analysis. Finally, the results from this work are used to determine covariance expressions for a variety of estimation problem examples and are also applied to the design of a dynamical system.

  10. The environmental zero-point problem in evolutionary reaction norm modeling.

    PubMed

    Ergon, Rolf

    2018-04-01

    There is a potential problem in present quantitative genetics evolutionary modeling based on reaction norms. Such models are state-space models, where the multivariate breeder's equation in some form is used as the state equation that propagates the population state forward in time. These models use the implicit assumption of a constant reference environment, in many cases set to zero. This zero-point is often the environment a population is adapted to, that is, where the expected geometric mean fitness is maximized. Such environmental reference values follow from the state of the population system, and they are thus population properties. The environment the population is adapted to, is, in other words, an internal population property, independent of the external environment. It is only when the external environment coincides with the internal reference environment, or vice versa, that the population is adapted to the current environment. This is formally a result of state-space modeling theory, which is an important theoretical basis for evolutionary modeling. The potential zero-point problem is present in all types of reaction norm models, parametrized as well as function-valued, and the problem does not disappear when the reference environment is set to zero. As the environmental reference values are population characteristics, they ought to be modeled as such. Whether such characteristics are evolvable is an open question, but considering the complexity of evolutionary processes, such evolvability cannot be excluded without good arguments. As a straightforward solution, I propose to model the reference values as evolvable mean traits in their own right, in addition to other reaction norm traits. However, solutions based on an evolvable G matrix are also possible.

  11. Fast and Adaptive Sparse Precision Matrix Estimation in High Dimensions

    PubMed Central

    Liu, Weidong; Luo, Xi

    2014-01-01

    This paper proposes a new method for estimating sparse precision matrices in the high dimensional setting. It has been popular to study fast computation and adaptive procedures for this problem. We propose a novel approach, called Sparse Column-wise Inverse Operator, to address these two issues. We analyze an adaptive procedure based on cross validation, and establish its convergence rate under the Frobenius norm. The convergence rates under other matrix norms are also established. This method also enjoys the advantage of fast computation for large-scale problems, via a coordinate descent algorithm. Numerical merits are illustrated using both simulated and real datasets. In particular, it performs favorably on an HIV brain tissue dataset and an ADHD resting-state fMRI dataset. PMID:25750463

  12. Serotonin and Social Norms

    PubMed Central

    Bilderbeck, Amy C.; Brown, Gordon D. A.; Read, Judi; Woolrich, Mark; Cowen, Phillip J.; Behrens, Tim E. J.

    2014-01-01

    How do people sustain resources for the benefit of individuals and communities and avoid the tragedy of the commons, in which shared resources become exhausted? In the present study, we examined the role of serotonin activity and social norms in the management of depletable resources. Healthy adults, alongside social partners, completed a multiplayer resource-dilemma game in which they repeatedly harvested from a partially replenishable monetary resource. Dietary tryptophan depletion, leading to reduced serotonin activity, was associated with aggressive harvesting strategies and disrupted use of the social norms given by distributions of other players’ harvests. Tryptophan-depleted participants more frequently exhausted the resource completely and also accumulated fewer rewards than participants who were not tryptophan depleted. Our findings show that rank-based social comparisons are crucial to the management of depletable resources, and that serotonin mediates responses to social norms. PMID:24815611

  13. The Moderating Role of Close versus Distal Peer Injunctive Norms and Interdependent Self-Construal in the Effects of Descriptive Norms on College Drinking.

    PubMed

    Yang, Bo

    2018-06-01

    Based on the theory of normative social behavior (Rimal & Real, 2005), this study examined the effects of descriptive norms, close versus distal peer injunctive norms, and interdependent self-construal on college students' intentions to consume alcohol. Results of a cross-sectional study conducted among U.S. college students (N = 581) found that descriptive norms, close, and distal peer injunctive norms had independent effects on college students' intentions to consume alcohol. Furthermore, close peer injunctive norms moderated the effects of descriptive norms on college students' intentions to consume alcohol and the interaction showed different patterns among students with a strong and weak interdependent self-construal. High levels of close peer injunctive norms weakened the relationship between descriptive norms and intentions to consume alcohol among students with a strong interdependent self-construal but strengthened the relationship between descriptive norms and intentions to consume alcohol among students with a weak interdependent self-construal. Implications of the findings for norms-based research and college drinking interventions are discussed.

  14. Time lag and communication in changing unpopular norms.

    PubMed

    Gërxhani, Klarita; Bruggeman, Jeroen

    2015-01-01

    Humans often coordinate their social lives through norms. When a large majority of people are dissatisfied with an existing norm, it seems obvious that they will change it. Often, however, this does not occur. We investigate how a time lag between individual support of a norm change and the change itself hinders such change, related to the critical mass of supporters needed to effectuate the change, and the (im)possibility of communicating about it. To isolate these factors, we utilize a laboratory experiment. As predicted, we find unambiguous effects of time lag on precluding norm change; a higher threshold for a critical mass does so as well. Communication facilitates choosing superior norms but it does not necessarily lead to norm change when the uncertainty on whether there will be a norm change in the future is high. Communication seems to help coordination on actions at the present but not the future. Hence, the uncertainty driven by time lag makes individuals choose the status quo, here the unpopular norm.

  15. Time Lag and Communication in Changing Unpopular Norms

    PubMed Central

    Gërxhani, Klarita; Bruggeman, Jeroen

    2015-01-01

    Humans often coordinate their social lives through norms. When a large majority of people are dissatisfied with an existing norm, it seems obvious that they will change it. Often, however, this does not occur. We investigate how a time lag between individual support of a norm change and the change itself hinders such change, related to the critical mass of supporters needed to effectuate the change, and the (im)possibility of communicating about it. To isolate these factors, we utilize a laboratory experiment. As predicted, we find unambiguous effects of time lag on precluding norm change; a higher threshold for a critical mass does so as well. Communication facilitates choosing superior norms but it does not necessarily lead to norm change when the uncertainty on whether there will be a norm change in the future is high. Communication seems to help coordination on actions at the present but not the future. Hence, the uncertainty driven by time lag makes individuals choose the status quo, here the unpopular norm. PMID:25880200

  16. Cultural Norms and Nonverbal Communication: An Illustration

    ERIC Educational Resources Information Center

    Chang, Yanrong

    2015-01-01

    Nonverbal communication takes place in specific cultural contexts and is influenced by cultural norms. Cultural norms are "social rules for what certain types of people should and should not do" (Hall, 2005). Different cultures might have different norms for nonverbal behaviors in specific social, relational, and geographical contexts.…

  17. Smoothed low rank and sparse matrix recovery by iteratively reweighted least squares minimization.

    PubMed

    Lu, Canyi; Lin, Zhouchen; Yan, Shuicheng

    2015-02-01

    This paper presents a general framework for solving the low-rank and/or sparse matrix minimization problems, which may involve multiple nonsmooth terms. The iteratively reweighted least squares (IRLSs) method is a fast solver, which smooths the objective function and minimizes it by alternately updating the variables and their weights. However, the traditional IRLS can only solve a sparse only or low rank only minimization problem with squared loss or an affine constraint. This paper generalizes IRLS to solve joint/mixed low-rank and sparse minimization problems, which are essential formulations for many tasks. As a concrete example, we solve the Schatten-p norm and l2,q-norm regularized low-rank representation problem by IRLS, and theoretically prove that the derived solution is a stationary point (globally optimal if p,q ≥ 1). Our convergence proof of IRLS is more general than previous one that depends on the special properties of the Schatten-p norm and l2,q-norm. Extensive experiments on both synthetic and real data sets demonstrate that our IRLS is much more efficient.

  18. An entropy-variables-based formulation of residual distribution schemes for non-equilibrium flows

    NASA Astrophysics Data System (ADS)

    Garicano-Mena, Jesús; Lani, Andrea; Degrez, Gérard

    2018-06-01

    In this paper we present an extension of Residual Distribution techniques for the simulation of compressible flows in non-equilibrium conditions. The latter are modeled by means of a state-of-the-art multi-species and two-temperature model. An entropy-based variable transformation that symmetrizes the projected advective Jacobian for such a thermophysical model is introduced. Moreover, the transformed advection Jacobian matrix presents a block diagonal structure, with mass-species and electronic-vibrational energy being completely decoupled from the momentum and total energy sub-system. The advantageous structure of the transformed advective Jacobian can be exploited by contour-integration-based Residual Distribution techniques: established schemes that operate on dense matrices can be substituted by the same scheme operating on the momentum-energy subsystem matrix and repeated application of scalar scheme to the mass-species and electronic-vibrational energy terms. Finally, the performance gain of the symmetrizing-variables formulation is quantified on a selection of representative testcases, ranging from subsonic to hypersonic, in inviscid or viscous conditions.

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Loef, P.A.; Smed, T.; Andersson, G.

    The minimum singular value of the power flow Jacobian matrix has been used as a static voltage stability index, indicating the distance between the studied operating point and the steady state voltage stability limit. In this paper a fast method to calculate the minimum singular value and the corresponding (left and right) singular vectors is presented. The main advantages of the developed algorithm are the small amount of computation time needed, and that it only requires information available from an ordinary program for power flow calculations. Furthermore, the proposed method fully utilizes the sparsity of the power flow Jacobian matrixmore » and hence the memory requirements for the computation are low. These advantages are preserved when applied to various submatrices of the Jacobian matrix, which can be useful in constructing special voltage stability indices. The developed algorithm was applied to small test systems as well as to a large (real size) system with over 1000 nodes, with satisfactory results.« less

  20. Norm Theory: Comparing Reality to Its Alternatives.

    ERIC Educational Resources Information Center

    Kahneman, Daniel; Miller, Dale T.

    1986-01-01

    A theory of norms and normality is applied to some phenomena of emotional responses, social judgment, and conversations about causes. Norm theory is applied in analyses of enhanced emotional response to events that have abnormal causes, of generation of prediction from observations of behavior, and of the role of norms. (Author/LMO)

  1. SU-F-18C-14: Hessian-Based Norm Penalty for Weighted Least-Square CBCT Reconstruction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sun, T; Sun, N; Tan, S

    Purpose: To develop a Hessian-based norm penalty for cone-beam CT (CBCT) reconstruction that has a similar ability in suppressing noise as the total variation (TV) penalty while avoiding the staircase effect and better preserving low-contrast objects. Methods: We extended the TV penalty to a Hessian-based norm penalty based on the Frobenius norm of the Hessian matrix of an image for CBCT reconstruction. The objective function was constructed using the penalized weighted least-square (PWLS) principle. An effective algorithm was developed to minimize the objective function using a majorization-minimization (MM) approach. We evaluated and compared the proposed penalty with the TV penaltymore » on a CatPhan 600 phantom and an anthropomorphic head phantom, each acquired at a low-dose protocol (10mA/10ms) and a high-dose protocol (80mA/12ms). For both penalties, contrast-to-noise (CNR) in four low-contrast regions-of-interest (ROIs) and the full-width-at-half-maximum (FWHM) of two point-like objects in constructed images were calculated and compared. Results: In the experiment of CatPhan 600 phantom, the Hessian-based norm penalty has slightly higher CNRs and approximately equivalent FWHM values compared with the TV penalty. In the experiment of the anthropomorphic head phantom at the low-dose protocol, the TV penalty result has several artificial piece-wise constant areas known as the staircase effect while in the Hessian-based norm penalty the image appears smoother and more similar to that of the FDK result using the high-dose protocol. Conclusion: The proposed Hessian-based norm penalty has a similar performance in suppressing noise to the TV penalty, but has a potential advantage in suppressing the staircase effect and preserving low-contrast objects. This work was supported in part by National Natural Science Foundation of China (NNSFC), under Grant Nos. 60971112 and 61375018, and Fundamental Research Funds for the Central Universities, under Grant No. 2012QN086

  2. Near-optimal matrix recovery from random linear measurements.

    PubMed

    Romanov, Elad; Gavish, Matan

    2018-06-25

    In matrix recovery from random linear measurements, one is interested in recovering an unknown M-by-N matrix [Formula: see text] from [Formula: see text] measurements [Formula: see text], where each [Formula: see text] is an M-by-N measurement matrix with i.i.d. random entries, [Formula: see text] We present a matrix recovery algorithm, based on approximate message passing, which iteratively applies an optimal singular-value shrinker-a nonconvex nonlinearity tailored specifically for matrix estimation. Our algorithm typically converges exponentially fast, offering a significant speedup over previously suggested matrix recovery algorithms, such as iterative solvers for nuclear norm minimization (NNM). It is well known that there is a recovery tradeoff between the information content of the object [Formula: see text] to be recovered (specifically, its matrix rank r) and the number of linear measurements n from which recovery is to be attempted. The precise tradeoff between r and n, beyond which recovery by a given algorithm becomes possible, traces the so-called phase transition curve of that algorithm in the [Formula: see text] plane. The phase transition curve of our algorithm is noticeably better than that of NNM. Interestingly, it is close to the information-theoretic lower bound for the minimal number of measurements needed for matrix recovery, making it not only state of the art in terms of convergence rate, but also near optimal in terms of the matrices it successfully recovers. Copyright © 2018 the Author(s). Published by PNAS.

  3. Bundles of Norms About Teen Sex and Pregnancy.

    PubMed

    Mollborn, Stefanie; Sennott, Christie

    2015-09-01

    Teen pregnancy is a cultural battleground in struggles over morality, education, and family. At its heart are norms about teen sex, contraception, pregnancy, and abortion. Analyzing 57 interviews with college students, we found that "bundles" of related norms shaped the messages teens hear. Teens did not think their communities encouraged teen sex or pregnancy, but normative messages differed greatly, with either moral or practical rationalizations. Teens readily identified multiple norms intended to regulate teen sex, contraception, abortion, childbearing, and the sanctioning of teen parents. Beyond influencing teens' behavior, norms shaped teenagers' public portrayals and post hoc justifications of their behavior. Although norm bundles are complex to measure, participants could summarize them succinctly. These bundles and their conflicting behavioral prescriptions create space for human agency in negotiating normative pressures. The norm bundles concept has implications for teen pregnancy prevention policies and can help revitalize social norms for understanding health behaviors. © The Author(s) 2014.

  4. The malleability of injunctive norms among college students.

    PubMed

    Prince, Mark A; Carey, Kate B

    2010-11-01

    Alcohol use among college students has been associated with injunctive norms, which refer to the perceived acceptability of excessive drinking, and descriptive norms, which refer to perceptions of actual drinking. The purpose of this study was to examine the effect of a brief injunctive norms manipulation on both injunctive and descriptive norms about drinking alcohol and to explore differences in the malleability of norms across referent groups, sex, and gender role. Participants were 265 undergraduates (43% male, 70% freshmen) who completed a web-based survey for course credit. A randomly selected half was exposed to a page of information-based feedback about typical student injunctive norms. Relative to the control condition, the manipulation produced lower injunctive and descriptive norms related to typical students' drinking but no change in either type of norm related to close friends. Femininity was associated with less permissive normative beliefs about the acceptability of excessive drinking whereas masculinity was associated with elevated perceptions of peer drinking, but neither sex nor gender role moderated the manipulation effect. We conclude that perceptions of peer approval of drinking are malleable with a very brief information-based manipulation. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. NEIGHBORHOOD NORMS AND SUBSTANCE USE AMONG TEENS

    PubMed Central

    Musick, Kelly; Seltzer, Judith A.; Schwartz, Christine R.

    2008-01-01

    This paper uses new data from the Los Angeles Family and Neighborhood Survey (L.A. FANS) to examine how neighborhood norms shape teenagers’ substance use. Specifically, it takes advantage of clustered data at the neighborhood level to relate adult neighbors’ attitudes and behavior with respect to smoking, drinking, and drugs, which we treat as norms, to teenagers’ own smoking, drinking, and drug use. We use hierarchical linear models to account for parents’ attitudes and behavior and other characteristics of individuals and families. We also investigate how the association between neighborhood norms and teen behavior depends on: (1) the strength of norms, as measured by consensus in neighbors’ attitudes and conformity in their behavior; (2) the willingness and ability of neighbors to enforce norms, for instance, by monitoring teens’ activities; and (3) the degree to which teens are exposed to their neighbors. We find little association between neighborhood norms and teen substance use, regardless of how we condition the relationship. We discuss possible theoretical and methodological explanations for this finding. PMID:18496598

  6. NWEA FAQ: RIT Scale Norms

    ERIC Educational Resources Information Center

    Northwest Evaluation Association, 2015

    2015-01-01

    Northwest Evaluation Association™ (NWEA™) conducts norming studies every several years to provide the best and most up-to-date information we can about student achievement and growth to better support educational decision-making. It is an important part of our commitment to our partners. The most recent NWEA norms were released in July 2015. Just…

  7. Sparse Covariance Matrix Estimation by DCA-Based Algorithms.

    PubMed

    Phan, Duy Nhat; Le Thi, Hoai An; Dinh, Tao Pham

    2017-11-01

    This letter proposes a novel approach using the [Formula: see text]-norm regularization for the sparse covariance matrix estimation (SCME) problem. The objective function of SCME problem is composed of a nonconvex part and the [Formula: see text] term, which is discontinuous and difficult to tackle. Appropriate DC (difference of convex functions) approximations of [Formula: see text]-norm are used that result in approximation SCME problems that are still nonconvex. DC programming and DCA (DC algorithm), powerful tools in nonconvex programming framework, are investigated. Two DC formulations are proposed and corresponding DCA schemes developed. Two applications of the SCME problem that are considered are classification via sparse quadratic discriminant analysis and portfolio optimization. A careful empirical experiment is performed through simulated and real data sets to study the performance of the proposed algorithms. Numerical results showed their efficiency and their superiority compared with seven state-of-the-art methods.

  8. A parallel algorithm for the eigenvalues and eigenvectors for a general complex matrix

    NASA Technical Reports Server (NTRS)

    Shroff, Gautam

    1989-01-01

    A new parallel Jacobi-like algorithm is developed for computing the eigenvalues of a general complex matrix. Most parallel methods for this parallel typically display only linear convergence. Sequential norm-reducing algorithms also exit and they display quadratic convergence in most cases. The new algorithm is a parallel form of the norm-reducing algorithm due to Eberlein. It is proven that the asymptotic convergence rate of this algorithm is quadratic. Numerical experiments are presented which demonstrate the quadratic convergence of the algorithm and certain situations where the convergence is slow are also identified. The algorithm promises to be very competitive on a variety of parallel architectures.

  9. On Some Separated Algorithms for Separable Nonlinear Least Squares Problems.

    PubMed

    Gan, Min; Chen, C L Philip; Chen, Guang-Yong; Chen, Long

    2017-10-03

    For a class of nonlinear least squares problems, it is usually very beneficial to separate the variables into a linear and a nonlinear part and take full advantage of reliable linear least squares techniques. Consequently, the original problem is turned into a reduced problem which involves only nonlinear parameters. We consider in this paper four separated algorithms for such problems. The first one is the variable projection (VP) algorithm with full Jacobian matrix of Golub and Pereyra. The second and third ones are VP algorithms with simplified Jacobian matrices proposed by Kaufman and Ruano et al. respectively. The fourth one only uses the gradient of the reduced problem. Monte Carlo experiments are conducted to compare the performance of these four algorithms. From the results of the experiments, we find that: 1) the simplified Jacobian proposed by Ruano et al. is not a good choice for the VP algorithm; moreover, it may render the algorithm hard to converge; 2) the fourth algorithm perform moderately among these four algorithms; 3) the VP algorithm with the full Jacobian matrix perform more stable than that of the VP algorithm with Kuafman's simplified one; and 4) the combination of VP algorithm and Levenberg-Marquardt method is more effective than the combination of VP algorithm and Gauss-Newton method.

  10. Collective action and the evolution of social norm internalization

    PubMed Central

    Gavrilets, Sergey; Richerson, Peter J.

    2017-01-01

    Human behavior is strongly affected by culturally transmitted norms and values. Certain norms are internalized (i.e., acting according to a norm becomes an end in itself rather than merely a tool in achieving certain goals or avoiding social sanctions). Humans’ capacity to internalize norms likely evolved in our ancestors to simplify solving certain challenges—including social ones. Here we study theoretically the evolutionary origins of the capacity to internalize norms. In our models, individuals can choose to participate in collective actions as well as punish free riders. In making their decisions, individuals attempt to maximize a utility function in which normative values are initially irrelevant but play an increasingly important role if the ability to internalize norms emerges. Using agent-based simulations, we show that norm internalization evolves under a wide range of conditions so that cooperation becomes “instinctive.” Norm internalization evolves much more easily and has much larger effects on behavior if groups promote peer punishment of free riders. Promoting only participation in collective actions is not effective. Typically, intermediate levels of norm internalization are most frequent but there are also cases with relatively small frequencies of “oversocialized” individuals willing to make extreme sacrifices for their groups no matter material costs, as well as “undersocialized” individuals completely immune to social norms. Evolving the ability to internalize norms was likely a crucial step on the path to large-scale human cooperation. PMID:28533363

  11. Collective action and the evolution of social norm internalization.

    PubMed

    Gavrilets, Sergey; Richerson, Peter J

    2017-06-06

    Human behavior is strongly affected by culturally transmitted norms and values. Certain norms are internalized (i.e., acting according to a norm becomes an end in itself rather than merely a tool in achieving certain goals or avoiding social sanctions). Humans' capacity to internalize norms likely evolved in our ancestors to simplify solving certain challenges-including social ones. Here we study theoretically the evolutionary origins of the capacity to internalize norms. In our models, individuals can choose to participate in collective actions as well as punish free riders. In making their decisions, individuals attempt to maximize a utility function in which normative values are initially irrelevant but play an increasingly important role if the ability to internalize norms emerges. Using agent-based simulations, we show that norm internalization evolves under a wide range of conditions so that cooperation becomes "instinctive." Norm internalization evolves much more easily and has much larger effects on behavior if groups promote peer punishment of free riders. Promoting only participation in collective actions is not effective. Typically, intermediate levels of norm internalization are most frequent but there are also cases with relatively small frequencies of "oversocialized" individuals willing to make extreme sacrifices for their groups no matter material costs, as well as "undersocialized" individuals completely immune to social norms. Evolving the ability to internalize norms was likely a crucial step on the path to large-scale human cooperation.

  12. Silence and table manners: when environments activate norms.

    PubMed

    Joly, Janneke F; Stapel, Diederik A; Lindenberg, Siegwart M

    2008-08-01

    Two studies tested the conditions under which an environment (e.g., library, restaurant) raises the relevance of environment-specific social norms (e.g., being quiet, using table manners). As hypothesized, the relevance of such norms is raised when environments are goal relevant ("I am going there later") and when they are humanized with people or the remnants of their presence (e.g., a glass of wine on a table). Two studies show that goal-relevant environments and humanized environments raise the perceived importance of norms (Study 1) and the intention to conform to norms (Study 2). Interestingly, in both studies, these effects reach beyond norms related to the environments used in the studies.

  13. EQ-5D Portuguese population norms.

    PubMed

    Ferreira, Lara Noronha; Ferreira, Pedro L; Pereira, Luis N; Oppe, Mark

    2014-03-01

    The EQ-5D is a widely used preference-based measure. Normative data can be used as references to analyze the effects of healthcare, determine the burden of disease and enable regional or country comparisons. Population norms for the EQ-5D exist for other countries but have not been previously published for Portugal. The purpose of this study was to derive EQ-5D Portuguese population norms. The EQ-5D was applied by phone interview to a random sample of the Portuguese general population (n = 1,500) stratified by age, gender and region. The Portuguese value set was used to derive the EQ-5D index. Mean values were computed by gender and age groups, marital status, educational attainment, region and other variables to obtain the EQ-5D Portuguese norms. Health status declines with advancing age, and women reported worse health status than men. These results are similar to other EQ-5D population health studies. This study provides Portuguese population health-related quality of life data measured by the EQ-5D that can be used as population norms. These norms can be used to inform Portuguese policy makers, health care professionals and researchers in issues related to health care policy and planning and quantification of treatment effects on health status.

  14. Principal Component Geostatistical Approach for large-dimensional inverse problems.

    PubMed

    Kitanidis, P K; Lee, J

    2014-07-01

    The quasi-linear geostatistical approach is for weakly nonlinear underdetermined inverse problems, such as Hydraulic Tomography and Electrical Resistivity Tomography. It provides best estimates as well as measures for uncertainty quantification. However, for its textbook implementation, the approach involves iterations, to reach an optimum, and requires the determination of the Jacobian matrix, i.e., the derivative of the observation function with respect to the unknown. Although there are elegant methods for the determination of the Jacobian, the cost is high when the number of unknowns, m , and the number of observations, n , is high. It is also wasteful to compute the Jacobian for points away from the optimum. Irrespective of the issue of computing derivatives, the computational cost of implementing the method is generally of the order of m 2 n , though there are methods to reduce the computational cost. In this work, we present an implementation that utilizes a matrix free in terms of the Jacobian matrix Gauss-Newton method and improves the scalability of the geostatistical inverse problem. For each iteration, it is required to perform K runs of the forward problem, where K is not just much smaller than m but can be smaller that n . The computational and storage cost of implementation of the inverse procedure scales roughly linearly with m instead of m 2 as in the textbook approach. For problems of very large m , this implementation constitutes a dramatic reduction in computational cost compared to the textbook approach. Results illustrate the validity of the approach and provide insight in the conditions under which this method perform best.

  15. On linearization and preconditioning for radiation diffusion coupled to material thermal conduction equations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feng, Tao, E-mail: fengtao2@mail.ustc.edu.cn; Graduate School of China Academy Engineering Physics, Beijing 100083; An, Hengbin, E-mail: an_hengbin@iapcm.ac.cn

    2013-03-01

    Jacobian-free Newton–Krylov (JFNK) method is an effective algorithm for solving large scale nonlinear equations. One of the most important advantages of JFNK method is that there is no necessity to form and store the Jacobian matrix of the nonlinear system when JFNK method is employed. However, an approximation of the Jacobian is needed for the purpose of preconditioning. In this paper, JFNK method is employed to solve a class of non-equilibrium radiation diffusion coupled to material thermal conduction equations, and two preconditioners are designed by linearizing the equations in two methods. Numerical results show that the two preconditioning methods canmore » improve the convergence behavior and efficiency of JFNK method.« less

  16. A Jacobian-free Newton Krylov method for mortar-discretized thermomechanical contact problems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hansen, Glen, E-mail: Glen.Hansen@inl.gov

    2011-07-20

    Multibody contact problems are common within the field of multiphysics simulation. Applications involving thermomechanical contact scenarios are also quite prevalent. Such problems can be challenging to solve due to the likelihood of thermal expansion affecting contact geometry which, in turn, can change the thermal behavior of the components being analyzed. This paper explores a simple model of a light water reactor nuclear fuel rod, which consists of cylindrical pellets of uranium dioxide (UO{sub 2}) fuel sealed within a Zircalloy cladding tube. The tube is initially filled with helium gas, which fills the gap between the pellets and cladding tube. Themore » accurate modeling of heat transfer across the gap between fuel pellets and the protective cladding is essential to understanding fuel performance, including cladding stress and behavior under irradiated conditions, which are factors that affect the lifetime of the fuel. The thermomechanical contact approach developed here is based on the mortar finite element method, where Lagrange multipliers are used to enforce weak continuity constraints at participating interfaces. In this formulation, the heat equation couples to linear mechanics through a thermal expansion term. Lagrange multipliers are used to formulate the continuity constraints for both heat flux and interface traction at contact interfaces. The resulting system of nonlinear algebraic equations are cast in residual form for solution of the transient problem. A Jacobian-free Newton Krylov method is used to provide for fully-coupled solution of the coupled thermal contact and heat equations.« less

  17. A Jacobian-Free Newton Krylov Method for Mortar-Discretized Thermomechanical Contact Problems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Glen Hansen

    2011-07-01

    Multibody contact problems are common within the field of multiphysics simulation. Applications involving thermomechanical contact scenarios are also quite prevalent. Such problems can be challenging to solve due to the likelihood of thermal expansion affecting contact geometry which, in turn, can change the thermal behavior of the components being analyzed. This paper explores a simple model of a light water reactor nuclear reactor fuel rod, which consists of cylindrical pellets of uranium dioxide (UO2) fuel sealed within a Zircalloy cladding tube. The tube is initially filled with helium gas, which fills the gap between the pellets and cladding tube. Themore » accurate modeling of heat transfer across the gap between fuel pellets and the protective cladding is essential to understanding fuel performance, including cladding stress and behavior under irradiated conditions, which are factors that affect the lifetime of the fuel. The thermomechanical contact approach developed here is based on the mortar finite element method, where Lagrange multipliers are used to enforce weak continuity constraints at participating interfaces. In this formulation, the heat equation couples to linear mechanics through a thermal expansion term. Lagrange multipliers are used to formulate the continuity constraints for both heat flux and interface traction at contact interfaces. The resulting system of nonlinear algebraic equations are cast in residual form for solution of the transient problem. A Jacobian-free Newton Krylov method is used to provide for fully-coupled solution of the coupled thermal contact and heat equations.« less

  18. A Call for a New National Norming Methodology.

    ERIC Educational Resources Information Center

    Ligon, Glynn; Mangino, Evangelina

    Issues related to achieving adequate national norms are reviewed, and a new methodology is proposed that would work to provide a true measure of national achievement levels on an annual basis and would enable reporting results in current-year norms. Statistical methodology and technology could combine to create a national norming process that…

  19. New algorithms to compute the nearness symmetric solution of the matrix equation.

    PubMed

    Peng, Zhen-Yun; Fang, Yang-Zhi; Xiao, Xian-Wei; Du, Dan-Dan

    2016-01-01

    In this paper we consider the nearness symmetric solution of the matrix equation AXB = C to a given matrix [Formula: see text] in the sense of the Frobenius norm. By discussing equivalent form of the considered problem, we derive some necessary and sufficient conditions for the matrix [Formula: see text] is a solution of the considered problem. Based on the idea of the alternating variable minimization with multiplier method, we propose two iterative methods to compute the solution of the considered problem, and analyze the global convergence results of the proposed algorithms. Numerical results illustrate the proposed methods are more effective than the existing two methods proposed in Peng et al. (Appl Math Comput 160:763-777, 2005) and Peng (Int J Comput Math 87: 1820-1830, 2010).

  20. Manifold regularized matrix completion for multi-label learning with ADMM.

    PubMed

    Liu, Bin; Li, Yingming; Xu, Zenglin

    2018-05-01

    Multi-label learning is a common machine learning problem arising from numerous real-world applications in diverse fields, e.g, natural language processing, bioinformatics, information retrieval and so on. Among various multi-label learning methods, the matrix completion approach has been regarded as a promising approach to transductive multi-label learning. By constructing a joint matrix comprising the feature matrix and the label matrix, the missing labels of test samples are regarded as missing values of the joint matrix. With the low-rank assumption of the constructed joint matrix, the missing labels can be recovered by minimizing its rank. Despite its success, most matrix completion based approaches ignore the smoothness assumption of unlabeled data, i.e., neighboring instances should also share a similar set of labels. Thus they may under exploit the intrinsic structures of data. In addition, the matrix completion problem can be less efficient. To this end, we propose to efficiently solve the multi-label learning problem as an enhanced matrix completion model with manifold regularization, where the graph Laplacian is used to ensure the label smoothness over it. To speed up the convergence of our model, we develop an efficient iterative algorithm, which solves the resulted nuclear norm minimization problem with the alternating direction method of multipliers (ADMM). Experiments on both synthetic and real-world data have shown the promising results of the proposed approach. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Switched periodic systems in discrete time: stability and input-output norms

    NASA Astrophysics Data System (ADS)

    Bolzern, Paolo; Colaneri, Patrizio

    2013-07-01

    This paper deals with the analysis of stability and the characterisation of input-output norms for discrete-time periodic switched linear systems. Such systems consist of a network of time-periodic linear subsystems sharing the same state vector and an exogenous switching signal that triggers the jumps between the subsystems. The overall system exhibits a complex dynamic behaviour due to the interplay between the time periodicity of the subsystem parameters and the switching signal. Both arbitrary switching signals and signals satisfying a dwell-time constraint are considered. Linear matrix inequality conditions for stability and guaranteed H2 and H∞ performances are provided. The results heavily rely on the merge of the theory of linear periodic systems and recent developments on switched linear time-invariant systems.

  2. College students' norm perception predicts reported use of protective behavioral strategies for alcohol consumption.

    PubMed

    Benton, Stephen L; Downey, Ronald G; Glider, Peggy J; Benton, Sherry A

    2008-11-01

    This study examined whether college students' descriptive norm perceptions of protective behavioral drinking strategies explain variance in use of such strategies, controlling for covariates of students' gender, typical number of drinks, and negative drinking consequences. Derivation (n = 7,960; 55.2% women) and replication (n = 8,534; 54.5% women) samples of undergraduate students completed the Campus Alcohol Survey in classroom settings. Students estimated how frequently other students used each of nine protective behavioral strategies (PBS) and how frequently they themselves used each strategy. All items assessing norm perception of PBS (NPPBS) had pattern matrix coefficients exceeding .50 on a single factor, and all contributed to the overall scale reliability (Cronbach's alpha = .81). Hierarchical regression analyses indicated NPPBS explained significant variance in PBS, controlling for covariates, and explained an additional 7% of variance (p < .001). A Gender x Scale (PBS, NPPBS) repeated-measures analysis of variance revealed students believed peers used PBS less frequently than they themselves did (eta(p) (2) = .091, p < .001). Such social distancing was greater in women (omega(effect) (2) = .151, p < .001) than in men (omega(effect) (2) = .001, p < .001). Consistent with the principle of false uniqueness, whereby individuals regard their own positive characteristics as rare, college students-especially women-underestimate how frequently other students use PBS. Such norm misperception may enhance students' feelings of competence and self-esteem. The positive relationship between NPPBS and PBS indicates students with high NPPBS are more likely to use the strategies themselves.

  3. Frontcountry encounter norms among three cultures

    Treesearch

    Jerry J. Vaske; Maureen P. Donnelly; Robert M. Doctor; James P. Petruzzi

    1995-01-01

    Existing normative studies have focused on backcountry encounter norms reported by North Americans. This study extends previous research by comparing encounter norms reported by three different cultures - North Americans, Europeans, and Japanese - in a frontcountry day use recreation area. Data were obtained from on-site surveys distributed at the Columbia Icefield in...

  4. Using Peer Injunctive Norms to Predict Early Adolescent Cigarette Smoking Intentions

    PubMed Central

    Zaleski, Adam C.; Aloise-Young, Patricia A.

    2013-01-01

    The present study investigated the importance of the perceived injunctive norm to predict early adolescent cigarette smoking intentions. A total of 271 6th graders completed a survey that included perceived prevalence of friend smoking (descriptive norm), perceptions of friends’ disapproval of smoking (injunctive norm), and future smoking intentions. Participants also listed their five best friends, in which the actual injunctive norm was calculated. Results showed that smoking intentions were significantly correlated with the perceived injunctive norm but not with the actual injunctive norm. Secondly, the perceived injunctive norm predicted an additional 3.4% of variance in smoking intentions above and beyond the perceived descriptive norm. These results demonstrate the importance of the perceived injunctive norm in predicting early adolescent smoking intentions. PMID:24078745

  5. Base norms and discrimination of generalized quantum channels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jenčová, A.

    2014-02-15

    We introduce and study norms in the space of hermitian matrices, obtained from base norms in positively generated subspaces. These norms are closely related to discrimination of so-called generalized quantum channels, including quantum states, channels, and networks. We further introduce generalized quantum decision problems and show that the maximal average payoffs of decision procedures are again given by these norms. We also study optimality of decision procedures, in particular, we obtain a necessary and sufficient condition under which an optimal 1-tester for discrimination of quantum channels exists, such that the input state is maximally entangled.

  6. Background recovery via motion-based robust principal component analysis with matrix factorization

    NASA Astrophysics Data System (ADS)

    Pan, Peng; Wang, Yongli; Zhou, Mingyuan; Sun, Zhipeng; He, Guoping

    2018-03-01

    Background recovery is a key technique in video analysis, but it still suffers from many challenges, such as camouflage, lighting changes, and diverse types of image noise. Robust principal component analysis (RPCA), which aims to recover a low-rank matrix and a sparse matrix, is a general framework for background recovery. The nuclear norm is widely used as a convex surrogate for the rank function in RPCA, which requires computing the singular value decomposition (SVD), a task that is increasingly costly as matrix sizes and ranks increase. However, matrix factorization greatly reduces the dimension of the matrix for which the SVD must be computed. Motion information has been shown to improve low-rank matrix recovery in RPCA, but this method still finds it difficult to handle original video data sets because of its batch-mode formulation and implementation. Hence, in this paper, we propose a motion-assisted RPCA model with matrix factorization (FM-RPCA) for background recovery. Moreover, an efficient linear alternating direction method of multipliers with a matrix factorization (FL-ADM) algorithm is designed for solving the proposed FM-RPCA model. Experimental results illustrate that the method provides stable results and is more efficient than the current state-of-the-art algorithms.

  7. Norm compliance and self-reported health among Swedish adolescents.

    PubMed

    Nygren, Karina; Janlert, Urban; Nygren, Lennart

    2011-02-01

    This study examines the relationship between norm compliance and self-reported health in adolescents, and how this differs between genders. Our specific aim was to investigate if extremely high norm compliance revealed any particular health patterns. This empirical study used a web-based survey from 2005, which was distributed to all students (n = 5,066) in years 7-9 of compulsory school within six municipalities in northern Sweden. The respondents answered questions about their general health as well as specific health problems such as headaches, stomach ache, sleeping difficulties and stress. Compliance was measured according to different norm-related behaviour, such as truancy, crime and use of tobacco, alcohol and narcotics. The majority of respondents reported good health and norm-compliant behaviour. Girls reported more health problems than boys, a difference that increased with age. Those who were more norm compliant reported better health, fewer somatic complaints and less stress, which goes against our initial hypothesis that extremely high norm compliance and self-reported ill-health are related. There seemed to be a stronger relationship between self-reported health and norm compliance for girls than boys, in absolute terms. The results clearly show a relationship between norm compliance and health, and suggest inequalities between genders.

  8. Variation in reaction norms: Statistical considerations and biological interpretation.

    PubMed

    Morrissey, Michael B; Liefting, Maartje

    2016-09-01

    Analysis of reaction norms, the functions by which the phenotype produced by a given genotype depends on the environment, is critical to studying many aspects of phenotypic evolution. Different techniques are available for quantifying different aspects of reaction norm variation. We examine what biological inferences can be drawn from some of the more readily applicable analyses for studying reaction norms. We adopt a strongly biologically motivated view, but draw on statistical theory to highlight strengths and drawbacks of different techniques. In particular, consideration of some formal statistical theory leads to revision of some recently, and forcefully, advocated opinions on reaction norm analysis. We clarify what simple analysis of the slope between mean phenotype in two environments can tell us about reaction norms, explore the conditions under which polynomial regression can provide robust inferences about reaction norm shape, and explore how different existing approaches may be used to draw inferences about variation in reaction norm shape. We show how mixed model-based approaches can provide more robust inferences than more commonly used multistep statistical approaches, and derive new metrics of the relative importance of variation in reaction norm intercepts, slopes, and curvatures. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  9. NORM -- The new kid on the block

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Estey, H.P.

    1991-12-31

    The existence of radioactive materials in accumulations of scale and sludge in oil and gas production equipment is a relatively new issue. This developing issue first gained international attention in 1981 when significant radiation levels were detected on oil and gas production platforms in the North Sea; it didn`t become a domestic issue until 1986 when a similar situation was detected in a Mississippi pipe yard. Most published papers on the occurrence of Naturally Occurring Radioactive Materials (NORM) in oil and gas production equipment have been based on studies of NORM-related activities in the United Kingdom (North Sea NORM). Thismore » paper addresses the occurrences and regulation of NORM in the US oil and gas production industry as experienced, witnessed and/or observed by the author over the past four years.« less

  10. "Be Nice": Wikipedia norms for supportive communication

    NASA Astrophysics Data System (ADS)

    Reagle, Joseph M.

    2010-04-01

    Wikipedia is acknowledged to have been home to "some bitter disputes." Indeed, conflict at Wikipedia is said to be "as addictive as cocaine." Yet, such observations are not cynical commentary but motivation for a collection of social norms. These norms speak to the intentional stance and communicative behaviors Wikipedians should adopt when interacting with one another. In the following pages, I provide a survey of these norms on the English Wikipedia and argue that they can be characterized as supportive based on Jack Gibb's classic communication article "Defensive Communication."

  11. How preschoolers react to norm violations is associated with culture.

    PubMed

    Gampe, Anja; Daum, Moritz M

    2018-01-01

    Children from the age of 3years understand social norms as such and enforce these norms in interactions with others. Differences in parental and institutional education across cultures make it likely that children receive divergent information about how to act in cases of norm violations. In the current study, we investigated whether cultural values are associated with the ways in which children react to norm violations. We tested 80 bicultural 3-year-olds with a norm enforcement paradigm and analyzed their reactions to norm violations. The reactions were correlated to the children's parental cultural values using the Global Leadership and Organizational Behavior Effectiveness (GLOBE) scales, and these results show that parental culture was associated with children's reactions to norm violations. The three strongest correlations were found for institutional collectivism, performance orientation, and assertiveness. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. [Cleanliness Norms 1964-1975].

    PubMed

    Noelle-Neumann, E

    1976-01-01

    In 1964 the Institut für Demoskopie Allensbach made a first survey taking stock of norms concerning cleanliness in the Federal Republic of Germany. At that time, 78% of respondents thought that the vogue among young people of cultivating an unkempt look was past or on the wane (Table 1.). Today we know that this fashion was an indicator of more serious desires for change in many different areas like politics, sexual morality, education and that its high point was still to come. In the fall of 1975 a second survey, modelled on the one of 1964, was conducted. Again, it concentrated on norms, not on behavior. As expected, norms have changed over this period but not in a one-directional or simple manner. In general, people are much more large-minded about children's looks: neat, clean school-dress, properly combed hair, clean shoes, all this and also holding their things in order has become less important in 1975 (Table 2). To carry a clean handkerchief is becoming oldfashioned (Table 3). On the other hand, principles of bringing-up children have not loosened concerning personal hygiene - brushing ones teeth, washing hands, feet, and neck, clean fingernails (Table 4). On one item related to protection of the environment, namely throwing around waste paper, standards have even become more strict (Table 5). With regard to school-leavers, norms of personal hygiene have generally become more strict (Table 6). As living standards have gone up and the number of full bathrooms has risen from 42% to 75% of households, norms of personal hygiene have also increased: one warm bath a week seemed enough to 56% of adults in 1964, but to only 32% in 1975 (Table 7). Also standards for changing underwear have changed a lot: in 1964 only 12% of respondents said "every day", in 1975 48% said so (Table 8). Even more stringent norms are applied to young women (Tables 9/10). For comparison: 1964 there were automatic washing machines in 16%, 1975 in 79% of households. Answers to questions

  13. Development and testing of the Youth Alcohol Norms Survey (YANS) instrument to measure youth alcohol norms and psychosocial influences.

    PubMed

    Burns, Sharyn K; Maycock, Bruce; Hildebrand, Janina; Zhao, Yun; Allsop, Steve; Lobo, Roanna; Howat, Peter

    2018-05-14

    This study aimed to develop and validate an online instrument to: (1) identify common alcohol-related social influences, norms and beliefs among adolescents; (2) clarify the process and pathways through which proalcohol norms are transmitted to adolescents; (3) describe the characteristics of social connections that contribute to the transmission of alcohol norms; and (4) identify the influence of alcohol marketing on adolescent norm development. The online Youth Alcohol Norms Survey (YANS) was administered in secondary schools in Western Australia PARTICIPANTS: Using a 2-week test-retest format, the YANS was administered to secondary school students (n=481, age=13-17 years, female 309, 64.2%). The development of the YANS was guided by social cognitive theory and comprised a systematic multistage process including evaluation of content and face validity. A 2-week test-retest format was employed. Exploratory factor analysis was conducted to determine the underlying factor structure of the instrument. Test-retest reliability was examined using intraclass correlation coefficient (ICC) and Cohen's kappa. A five-factor structure with meaningful components and robust factorial loads was identified, and the five factors were labelled as 'individual attitudes and beliefs', 'peer and community identity', 'sibling influences', 'school and community connectedness' and 'injunctive norms', respectively. The instrument demonstrated stability across the test-retest procedure (ICC=0.68-0.88, Cohen's kappa coefficient=0.69) for most variables. The results support the reliability and factorial validity of this instrument. The YANS presents a promising tool, which enables comprehensive assessment of reciprocal individual, behavioural and environmental factors that influence alcohol-related norms among adolescents. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise

  14. A graph-based approach to auditing RxNorm.

    PubMed

    Bodenreider, Olivier; Peters, Lee B

    2009-06-01

    RxNorm is a standardized nomenclature for clinical drug entities developed by the National Library of Medicine. In this paper, we audit relations in RxNorm for consistency and completeness through the systematic analysis of the graph of its concepts and relationships. The representation of multi-ingredient drugs is normalized in order to make it compatible with that of single-ingredient drugs. All meaningful paths between two nodes in the type graph are computed and instantiated. Alternate paths are automatically compared and manually inspected in case of inconsistency. The 115 meaningful paths identified in the type graph can be grouped into 28 groups with respect to start and end nodes. Of the 19 groups of alternate paths (i.e., with two or more paths) between the start and end nodes, 9 (47%) exhibit inconsistencies. Overall, 28 (24%) of the 115 paths are inconsistent with other alternate paths. A total of 348 inconsistencies were identified in the April 2008 version of RxNorm and reported to the RxNorm team, of which 215 (62%) had been corrected in the January 2009 version of RxNorm. The inconsistencies identified involve missing nodes (93), missing links (17), extraneous links (237) and one case of mix-up between two ingredients. Our auditing method proved effective in identifying a limited number of errors that had defeated the quality assurance mechanisms currently in place in the RxNorm production system. Some recommendations for the development of RxNorm are provided.

  15. Regulating Gender Performances: Power and Gender Norms in Faculty Work

    ERIC Educational Resources Information Center

    Lester, Jaime

    2011-01-01

    Despite the steady increase of women in faculty positions over the last few decades and the research on gender norms in the academy, what remains unclear is why many female faculty continue to conform to gender norms despite their acknowledgement of the discriminatory nature of these norms, their dissatisfaction performing the norms, and the lack…

  16. Social Norms Shift Preferences for Healthy and Unhealthy Foods

    PubMed Central

    Templeton, Emma M.; Stanton, Michael V.; Zaki, Jamil

    2016-01-01

    This research investigated whether people change their food preferences and eating behavior in response to health-based social norms. One hundred twenty participants rated a series of healthy and unhealthy food images. After each rating, participants sometimes viewed a rating that ostensibly represented the average rating of previous participants. In fact, these average ratings were manipulated to convey a particular social norm. Participants either saw average ratings that favored healthy foods, favored unhealthy foods, or did not see any average ratings. Participants then re-rated those same food images after approximately ten minutes and again three days later. After the norm manipulation, participants were given the chance to take as many M&Ms as they wanted. Participants exposed to a healthy social norm consistently reported lower preferences for unhealthy foods as compared to participants in the other two conditions. This preference difference persisted three days after the social norm manipulation. However, health-based social norm manipulations did not influence the amount of M&Ms participants took. Although health-based social norm manipulations can influence stated food preferences, in this case they did not influence subsequent eating behavior. PMID:27861518

  17. Matrix basis for plane and modal waves in a Timoshenko beam

    PubMed Central

    Tolfo, Daniela de Rosso; Tonetto, Leticia

    2016-01-01

    Plane waves and modal waves of the Timoshenko beam model are characterized in closed form by introducing robust matrix basis that behave according to the nature of frequency and wave or modal numbers. These new characterizations are given in terms of a finite number of coupling matrices and closed form generating scalar functions. Through Liouville’s technique, these latter are well behaved at critical or static situations. Eigenanalysis is formulated for exponential and modal waves. Modal waves are superposition of four plane waves, but there are plane waves that cannot be modal waves. Reflected and transmitted waves at an interface point are formulated in matrix terms, regardless of having a conservative or a dissipative situation. The matrix representation of modal waves is used in a crack problem for determining the reflected and transmitted matrices. Their euclidean norms are seen to be dominated by certain components at low and high frequencies. The matrix basis technique is also used with a non-local Timoshenko model and with the wave interaction with a boundary. The matrix basis allows to characterize reflected and transmitted waves in spectral and non-spectral form. PMID:28018668

  18. Matrix basis for plane and modal waves in a Timoshenko beam.

    PubMed

    Claeyssen, Julio Cesar Ruiz; Tolfo, Daniela de Rosso; Tonetto, Leticia

    2016-11-01

    Plane waves and modal waves of the Timoshenko beam model are characterized in closed form by introducing robust matrix basis that behave according to the nature of frequency and wave or modal numbers. These new characterizations are given in terms of a finite number of coupling matrices and closed form generating scalar functions. Through Liouville's technique, these latter are well behaved at critical or static situations. Eigenanalysis is formulated for exponential and modal waves. Modal waves are superposition of four plane waves, but there are plane waves that cannot be modal waves. Reflected and transmitted waves at an interface point are formulated in matrix terms, regardless of having a conservative or a dissipative situation. The matrix representation of modal waves is used in a crack problem for determining the reflected and transmitted matrices. Their euclidean norms are seen to be dominated by certain components at low and high frequencies. The matrix basis technique is also used with a non-local Timoshenko model and with the wave interaction with a boundary. The matrix basis allows to characterize reflected and transmitted waves in spectral and non-spectral form.

  19. Potential Applications of Social Norms Theory to Academic Advising

    ERIC Educational Resources Information Center

    Demetriou, Cynthia

    2005-01-01

    Since the mid-1990s, social norms theory has become prevalent in student development literature and research. Subsequently, social norms interventions to change student behavior have spread across campuses nationwide through marketing campaigns. Theorists and practitioners have applied the social norms approach to primarily health-related student…

  20. Principal Component Geostatistical Approach for large-dimensional inverse problems

    PubMed Central

    Kitanidis, P K; Lee, J

    2014-01-01

    The quasi-linear geostatistical approach is for weakly nonlinear underdetermined inverse problems, such as Hydraulic Tomography and Electrical Resistivity Tomography. It provides best estimates as well as measures for uncertainty quantification. However, for its textbook implementation, the approach involves iterations, to reach an optimum, and requires the determination of the Jacobian matrix, i.e., the derivative of the observation function with respect to the unknown. Although there are elegant methods for the determination of the Jacobian, the cost is high when the number of unknowns, m, and the number of observations, n, is high. It is also wasteful to compute the Jacobian for points away from the optimum. Irrespective of the issue of computing derivatives, the computational cost of implementing the method is generally of the order of m2n, though there are methods to reduce the computational cost. In this work, we present an implementation that utilizes a matrix free in terms of the Jacobian matrix Gauss-Newton method and improves the scalability of the geostatistical inverse problem. For each iteration, it is required to perform K runs of the forward problem, where K is not just much smaller than m but can be smaller that n. The computational and storage cost of implementation of the inverse procedure scales roughly linearly with m instead of m2 as in the textbook approach. For problems of very large m, this implementation constitutes a dramatic reduction in computational cost compared to the textbook approach. Results illustrate the validity of the approach and provide insight in the conditions under which this method perform best. PMID:25558113

  1. Systematic sparse matrix error control for linear scaling electronic structure calculations.

    PubMed

    Rubensson, Emanuel H; Sałek, Paweł

    2005-11-30

    Efficient truncation criteria used in multiatom blocked sparse matrix operations for ab initio calculations are proposed. As system size increases, so does the need to stay on top of errors and still achieve high performance. A variant of a blocked sparse matrix algebra to achieve strict error control with good performance is proposed. The presented idea is that the condition to drop a certain submatrix should depend not only on the magnitude of that particular submatrix, but also on which other submatrices that are dropped. The decision to remove a certain submatrix is based on the contribution the removal would cause to the error in the chosen norm. We study the effect of an accumulated truncation error in iterative algorithms like trace correcting density matrix purification. One way to reduce the initial exponential growth of this error is presented. The presented error control for a sparse blocked matrix toolbox allows for achieving optimal performance by performing only necessary operations needed to maintain the requested level of accuracy. Copyright 2005 Wiley Periodicals, Inc.

  2. Group bias in cooperative norm enforcement

    PubMed Central

    McAuliffe, Katherine; Dunham, Yarrow

    2016-01-01

    A hallmark of human social cognition is the tendency for both adults and children to favour members of their own groups. Critically, this in-group bias exerts a strong influence on cooperative decision-making: people (i) tend to share more with members of their in-group and (ii) differentially enforce fairness norms depending on the group membership of their interaction partners. But why do people show these group biases in cooperation? One possibility is that the enforcement of cooperative norm violations is an evolved mechanism supporting within-group cooperation (Norms-Focused Hypothesis). Alternatively, group bias in cooperation could be a by-product of more general affective preferences for in-group members (Mere Preferences Hypothesis). Here, we appraise evidence from studies of both adults and children with the goal of understanding whether one of these two accounts is better supported by existing data. While the pattern of evidence is complex, much of it is broadly consistent with the Mere Preferences Hypothesis and little is uniquely supportive of the Norms-Focused Hypothesis. We highlight possible reasons for this complexity and suggest ways that future work can continue to help us understand the important relationship between group bias and cooperation. PMID:26644592

  3. Peer punishment promotes enforcement of bad social norms.

    PubMed

    Abbink, Klaus; Gangadharan, Lata; Handfield, Toby; Thrasher, John

    2017-09-20

    Social norms are an important element in explaining how humans achieve very high levels of cooperative activity. It is widely observed that, when norms can be enforced by peer punishment, groups are able to resolve social dilemmas in prosocial, cooperative ways. Here we show that punishment can also encourage participation in destructive behaviours that are harmful to group welfare, and that this phenomenon is mediated by a social norm. In a variation of a public goods game, in which the return to investment is negative for both group and individual, we find that the opportunity to punish led to higher levels of contribution, thereby harming collective payoffs. A second experiment confirmed that, independently of whether punishment is available, a majority of subjects regard the efficient behaviour of non-contribution as socially inappropriate. The results show that simply providing a punishment opportunity does not guarantee that punishment will be used for socially beneficial ends, because the social norms that influence punishment behaviour may themselves be destructive.Punishment by peers can enforce social norms, such as contributing to a public good. Here, Abbink and colleagues show that individuals will enforce norms even when contributions reduce the net benefit of the group, resulting in the maintenance of wasteful contributions.

  4. The Augmented Lagrange Multipliers Method for Matrix Completion from Corrupted Samplings with Application to Mixed Gaussian-Impulse Noise Removal

    PubMed Central

    Meng, Fan; Yang, Xiaomei; Zhou, Chenghu

    2014-01-01

    This paper studies the problem of the restoration of images corrupted by mixed Gaussian-impulse noise. In recent years, low-rank matrix reconstruction has become a research hotspot in many scientific and engineering domains such as machine learning, image processing, computer vision and bioinformatics, which mainly involves the problem of matrix completion and robust principal component analysis, namely recovering a low-rank matrix from an incomplete but accurate sampling subset of its entries and from an observed data matrix with an unknown fraction of its entries being arbitrarily corrupted, respectively. Inspired by these ideas, we consider the problem of recovering a low-rank matrix from an incomplete sampling subset of its entries with an unknown fraction of the samplings contaminated by arbitrary errors, which is defined as the problem of matrix completion from corrupted samplings and modeled as a convex optimization problem that minimizes a combination of the nuclear norm and the -norm in this paper. Meanwhile, we put forward a novel and effective algorithm called augmented Lagrange multipliers to exactly solve the problem. For mixed Gaussian-impulse noise removal, we regard it as the problem of matrix completion from corrupted samplings, and restore the noisy image following an impulse-detecting procedure. Compared with some existing methods for mixed noise removal, the recovery quality performance of our method is dominant if images possess low-rank features such as geometrically regular textures and similar structured contents; especially when the density of impulse noise is relatively high and the variance of Gaussian noise is small, our method can outperform the traditional methods significantly not only in the simultaneous removal of Gaussian noise and impulse noise, and the restoration ability for a low-rank image matrix, but also in the preservation of textures and details in the image. PMID:25248103

  5. Correlation between the norm and the geometry of minimal networks

    NASA Astrophysics Data System (ADS)

    Laut, I. L.

    2017-05-01

    The paper is concerned with the inverse problem of the minimal Steiner network problem in a normed linear space. Namely, given a normed space in which all minimal networks are known for any finite point set, the problem is to describe all the norms on this space for which the minimal networks are the same as for the original norm. We survey the available results and prove that in the plane a rotund differentiable norm determines a distinctive set of minimal Steiner networks. In a two-dimensional space with rotund differentiable norm the coordinates of interior vertices of a nondegenerate minimal parametric network are shown to vary continuously under small deformations of the boundary set, and the turn direction of the network is determined. Bibliography: 15 titles.

  6. Full waveform inversion using envelope-based global correlation norm

    NASA Astrophysics Data System (ADS)

    Oh, Ju-Won; Alkhalifah, Tariq

    2018-05-01

    To increase the feasibility of full waveform inversion on real data, we suggest a new objective function, which is defined as the global correlation of the envelopes of modelled and observed data. The envelope-based global correlation norm has the advantage of the envelope inversion that generates artificial low-frequency information, which provides the possibility to recover long-wavelength structure in an early stage. In addition, the envelope-based global correlation norm maintains the advantage of the global correlation norm, which reduces the sensitivity of the misfit to amplitude errors so that the performance of inversion on real data can be enhanced when the exact source wavelet is not available and more complex physics are ignored. Through the synthetic example for 2-D SEG/EAGE overthrust model with inaccurate source wavelet, we compare the performance of four different approaches, which are the least-squares waveform inversion, least-squares envelope inversion, global correlation norm and envelope-based global correlation norm. Finally, we apply the envelope-based global correlation norm on the 3-D Ocean Bottom Cable (OBC) data from the North Sea. The envelope-based global correlation norm captures the strong reflections from the high-velocity caprock and generates artificial low-frequency reflection energy that helps us recover long-wavelength structure of the model domain in the early stages. From this long-wavelength model, the conventional global correlation norm is sequentially applied to invert for higher-resolution features of the model.

  7. A Graph-based Approach to Auditing RxNorm

    PubMed Central

    Bodenreider, Olivier; Peters, Lee B.

    2009-01-01

    Objectives RxNorm is a standardized nomenclature for clinical drug entities developed by the National Library of Medicine. In this paper, we audit relations in RxNorm for consistency and completeness through the systematic analysis of the graph of its concepts and relationships. Methods The representation of multi-ingredient drugs is normalized in order to make it compatible with that of single-ingredient drugs. All meaningful paths between two nodes in the type graph are computed and instantiated. Alternate paths are automatically compared and manually inspected in case of inconsistency. Results The 115 meaningful paths identified in the type graph can be grouped into 28 groups with respect to start and end nodes. Of the 19 groups of alternate paths (i.e., with two or more paths) between the start and end nodes, 9 (47%) exhibit inconsistencies. Overall, 28 (24%) of the 115 paths are inconsistent with other alternate paths. A total of 348 inconsistencies were identified in the April 2008 version of RxNorm and reported to the RxNorm team, of which 215 (62%) had been corrected in the January 2009 version of RxNorm. Conclusion The inconsistencies identified involve missing nodes (93), missing links (17), extraneous links (237) and one case of mix-up between two ingredients. Our auditing method proved effective in identifying a limited number of errors that had defeated the quality assurance mechanisms currently in place in the RxNorm production system. Some recommendations for the development of RxNorm are provided. PMID:19394440

  8. Changing Gender Norms and Marriage Dynamics in the United States.

    PubMed

    Pessin, Léa

    2018-02-01

    Using a regional measure of gender norms from the General Social Surveys together with marital histories from the Panel Study of Income Dynamics, this study explored how gender norms were associated with women's marriage dynamics between 1968 and 2012. Results suggested that a higher prevalence of egalitarian gender norms predicted a decline in marriage formation. This decline was, however, only true for women without a college degree. For college-educated women, the association between gender norms and marriage formation became positive when gender egalitarianism prevailed. The findings also revealed an inverted U-shaped relationship between gender norms and divorce: an initial increase in divorce was observed when gender norms were predominantly traditional. The association, however, reversed as gender norms became egalitarian. No differences by education were found for divorce. The findings partially support the gender revolution framework but also highlight greater barriers to marriage for low-educated women as societies embrace gender equality.

  9. Current Trends in the study of Gender Norms and Health Behaviors

    PubMed Central

    Fleming, Paul J.; Agnew-Brune, Christine

    2015-01-01

    Gender norms are recognized as one of the major social determinants of health and gender norms can have implications for an individual’s health behaviors. This paper reviews the recent advances in research on the role of gender norms on health behaviors most associated with morbidity and mortality. We find that (1) the study of gender norms and health behaviors is varied across different types of health behaviors, (2) research on masculinity and masculine norms appears to have taken on an increasing proportion of studies on the relationship between gender norms and health, and (3) we are seeing new and varied populations integrated into the study of gender norms and health behaviors. PMID:26075291

  10. Vitamin D supplementation in young children: associations with Theory of Planned Behaviour variables, descriptive norms, moral norms and habits.

    PubMed

    de Nooijer, Jascha; Onnink, Monique; van Assema, Patricia

    2010-08-01

    In the Netherlands, a supplementation of 10 microg vitamin D is recommended for children (aged 0-4 years), given that vitamin D contributes to the development of healthy bones and deficiency during childhood is a risk factor for osteoporosis at a later age. However, only 60 % of the Dutch children receive sufficient vitamin D supplementation a day. In order to develop interventions to improve supplementation intake, it is necessary to gain insight into the behaviour of parents in giving their children vitamin D supplementation and its association with variables of the Theory of Planned Behaviour, moral and descriptive norms and habits. A cross-sectional survey to assess present supplementation-related behaviour, knowledge, received information, intention, attitude, subjective norm, perceived behavioural control, moral norm, descriptive norm and habit. Data obtained from a representative Internet Panel by means of electronic questionnaires. Parents (n 270) of children aged 0-4 years. Half of the parents (48.9 %) gave their child sufficient vitamin D supplementation. Giving the supplement at a fixed time, a positive intention and habit were significantly associated with actual behaviour. The higher age of the child, first-born status, a fixed time for taking vitamin supplementation, descriptive norm and moral obligation were significantly associated with intention. These results indicate that because many parents do not give their children adequate vitamin D supplementation, the promotion of supplementation during the first years of life is a necessity. Effective yet simple strategies should be developed, focused on improving moral obligation, descriptive norms and habit formation.

  11. Brain responses to social norms: Meta-analyses of fMRI studies.

    PubMed

    Zinchenko, Oksana; Arsalidou, Marie

    2018-02-01

    Social norms have a critical role in everyday decision-making, as frequent interaction with others regulates our behavior. Neuroimaging studies show that social-based and fairness-related decision-making activates an inconsistent set of areas, which sometimes includes the anterior insula, anterior cingulate cortex, and others lateral prefrontal cortices. Social-based decision-making is complex and variability in findings may be driven by socio-cognitive activities related to social norms. To distinguish among social-cognitive activities related to social norms, we identified 36 eligible articles in the functional magnetic resonance imaging (fMRI) literature, which we separate into two categories (a) social norm representation and (b) norm violations. The majority of original articles (>60%) used tasks associated with fairness norms and decision-making, such as ultimatum game, dictator game, or prisoner's dilemma; the rest used tasks associated to violation of moral norms, such as scenarios and sentences of moral depravity ratings. Using quantitative meta-analyses, we report common and distinct brain areas that show concordance as a function of category. Specifically, concordance in ventromedial prefrontal regions is distinct to social norm representation processing, whereas concordance in right insula, dorsolateral prefrontal, and dorsal cingulate cortices is distinct to norm violation processing. We propose a neurocognitive model of social norms for healthy adults, which could help guide future research in social norm compliance and mechanisms of its enforcement. © 2017 Wiley Periodicals, Inc.

  12. Tutorial: Calculating Percentile Rank and Percentile Norms Using SPSS

    ERIC Educational Resources Information Center

    Baumgartner, Ted A.

    2009-01-01

    Practitioners can benefit from using norms, but they often have to develop their own percentile rank and percentile norms. This article is a tutorial on how to quickly and easily calculate percentile rank and percentile norms using SPSS, and this information is presented for a data set. Some issues in calculating percentile rank and percentile…

  13. Impact of the Choice of Normalization Method on Molecular Cancer Class Discovery Using Nonnegative Matrix Factorization.

    PubMed

    Yang, Haixuan; Seoighe, Cathal

    2016-01-01

    Nonnegative Matrix Factorization (NMF) has proved to be an effective method for unsupervised clustering analysis of gene expression data. By the nonnegativity constraint, NMF provides a decomposition of the data matrix into two matrices that have been used for clustering analysis. However, the decomposition is not unique. This allows different clustering results to be obtained, resulting in different interpretations of the decomposition. To alleviate this problem, some existing methods directly enforce uniqueness to some extent by adding regularization terms in the NMF objective function. Alternatively, various normalization methods have been applied to the factor matrices; however, the effects of the choice of normalization have not been carefully investigated. Here we investigate the performance of NMF for the task of cancer class discovery, under a wide range of normalization choices. After extensive evaluations, we observe that the maximum norm showed the best performance, although the maximum norm has not previously been used for NMF. Matlab codes are freely available from: http://maths.nuigalway.ie/~haixuanyang/pNMF/pNMF.htm.

  14. Solution des systemes de controle de grandes dimensions basee sur les boucles de retroaction dans la simulation des reseaux electriques

    NASA Astrophysics Data System (ADS)

    Mugombozi, Chuma Francis

    The generation of electrical energy, as well as its transportation and consumption, requires complex control systems for the regulation of power and frequency. These control systems must take into account, among others, new energy sources such as wind energy and new technologies for interconnection by high voltage DC link. These control systems must be able to monitor and achieve such regulation in accordance with the dynamics of the energy source, faults and other events which may induce transients phenomena into the power network. Such transients conditions have to be analyzed using the most accurate and detailed hence, complex models of control system. In addition, in the feasibility study phase, the calibration or the setup of equipment as well as in the operation of the power network, one may require decision aid tools for engineers. This includes, for instance, knowledge of energy dissipated into the arresters in transient analysis. These tools use simulation programs data as inputs and may require that complex functions be solved with numerical methods. These functions are part of control system in computer simulator. Moreover, the simulation evolves in a broader context of the development of digital controller, distributed and parallel high performance computing and rapid evolutions in computer (multiprocessor) technology. In such context, a continuing improvement of the control equations solver is welcomed. Control systems are modelled using ax=b simultaneous system of equations. These equations are sometimes non-linear with feedback loops and thus require iterative Newton methods, including the formation of a Jacobian matrix and ordering as well as processing by graph theory tools. The proposed approach is based on the formulation of a reduced rank Jacobian matrix. The dimension is reduced up to the count of feedback loops. With this new approach, gains in computation speed are expected without compromising its accuracy when compared to classical full

  15. Perceived peer drinking norms and responsible drinking in UK university settings.

    PubMed

    Robinson, Eric; Jones, Andrew; Christiansen, Paul; Field, Matt

    2014-09-01

    Heavy drinking is common among students at UK universities. US students overestimate how much their peers drink and correcting this through the use of social norm messages may promote responsible drinking. We tested whether there is an association between perceived campus drinking norms and usual drinking behavior in UK university students and whether norm messages about responsible drinking correct normative misperceptions and increase students' intentions to drink responsibly. 1,020 UK university students took part in an online study. Participants were exposed to one of five message types: a descriptive norm, an injunctive norm, a descriptive and injunctive norm, or one of two control messages. Message credibility was assessed. Afterwards participants completed measures of intentions to drink responsibly and we measured usual drinking habits and perceptions of peer drinking. Perceptions of peer drinking were associated modestly with usual drinking behavior, whereby participants who believed other students drank responsibly also drank responsibly. Norm messages changed normative perceptions, but not in the target population of participants who underestimated responsible drinking in their peers at baseline. Norm messages did not increase intentions to drink responsibly and although based on accurate data, norm messages were not seen as credible. In this UK based study, although perceived social norms about peer drinking were associated with individual differences in drinking habits, campus wide norm messages about responsible drinking did not affect students' intentions to drink more responsibly. More research is required to determine if this approach can be applied to UK settings.

  16. The Role of Perceived Injunctive Alcohol Norms in Adolescent Drinking Behavior

    PubMed Central

    Pedersen, Eric R.; Osilla, Karen Chan; Miles, Jeremy N.V.; Tucker, Joan S.; Ewing, Brett A.; Shih, Regina A.; D’Amico, Elizabeth J.

    2016-01-01

    Peers have a major influence on youth during adolescence, and perceptions about peer alcohol use (perceived norms) are often associated with personal drinking behavior among youth. Most of the research on perceived norms among adolescents focuses on perceived descriptive norms only, or perceptions about peers’ behavior, and correcting these perceptions are a major focus of many prevention programs with adolescents. In contrast, perceived injunctive norms, which are personal perceptions about peers’ attitudes regarding the acceptability of behaviors, have been minimally examined in the adolescent drinking literature. Yet correcting perceptions about these perceived peer attitudes may be an important component to include in prevention programs with youth. Using a sample of 2,493 high school-aged youth (mean age = 17.3), we assessed drinking behavior (past year use; past month frequency, quantity, and peak drinks), drinking consequences, and perceived descriptive and injunctive norms to examine the relationships of perceived injunctive and descriptive norms on adolescent drinking behavior. Findings indicated that although perceived descriptive norms were associated with some drinking outcomes (past year use; past month frequency; past month quantity; peak drinks), perceived injunctive norms were associated with all drinking outcomes, including outcomes of consequences, even after controlling for perceived descriptive norms. Findings suggest that consideration of perceived injunctive norms may be important in models of adolescent drinking. Prevention programs that do not include injunctive norms feedback may miss an important opportunity to enhance effectiveness of such prevention programs targeting adolescent alcohol use. PMID:27978424

  17. Evaluating the implementation of RxNorm in ambulatory electronic prescriptions

    PubMed Central

    Ward-Charlerie, Stacy; Rupp, Michael T; Kilbourne, John; Amin, Vishal P; Ruiz, Joshua

    2016-01-01

    Objective RxNorm is a standardized drug nomenclature maintained by the National Library of Medicine that has been recommended as an alternative to the National Drug Code (NDC) terminology for use in electronic prescribing. The objective of this study was to evaluate the implementation of RxNorm in ambulatory care electronic prescriptions (e-prescriptions). Methods We analyzed a random sample of 49 997 e-prescriptions that were received by 7391 locations of a national retail pharmacy chain during a single day in April 2014. The e-prescriptions in the sample were generated by 37 801 ambulatory care prescribers using 519 different e-prescribing software applications. Results We found that 97.9% of e-prescriptions in the study sample could be accurately represented by an RxNorm identifier. However, RxNorm identifiers were actually used as drug identifiers in only 16 433 (33.0%) e-prescriptions. Another 431 (2.5%) e-prescriptions that used RxNorm identifiers had a discrepancy in the corresponding Drug Database Code qualifier field or did not have a qualifier (Term Type) at all. In 10 e-prescriptions (0.06%), the free-text drug description and the RxNorm concept unique identifier pointed to completely different drug concepts, and in 7 e-prescriptions (0.04%), the NDC and RxNorm drug identifiers pointed to completely different drug concepts. Discussion The National Library of Medicine continues to enhance the RxNorm terminology and expand its scope. This study illustrates the need for technology vendors to improve their implementation of RxNorm; doing so will accelerate the adoption of RxNorm as the preferred alternative to using the NDC terminology in e-prescribing. PMID:26510879

  18. Techniques for Computation of Frequency Limited H∞ Norm

    NASA Astrophysics Data System (ADS)

    Haider, Shafiq; Ghafoor, Abdul; Imran, Muhammad; Fahad Mumtaz, Malik

    2018-01-01

    Traditional H ∞ norm depicts peak system gain over infinite frequency range, but many applications like filter design, model order reduction and controller design etc. require computation of peak system gain over specific frequency interval rather than infinite range. In present work, new computationally efficient techniques for computation of H ∞ norm over frequency limited interval are proposed. Proposed techniques link norm computation with maximum singular value of the system in limited frequency interval. Numerical examples are incorporated to validate the proposed concept.

  19. Four year-olds use norm-based coding for face identity.

    PubMed

    Jeffery, Linda; Read, Ainsley; Rhodes, Gillian

    2013-05-01

    Norm-based coding, in which faces are coded as deviations from an average face, is an efficient way of coding visual patterns that share a common structure and must be distinguished by subtle variations that define individuals. Adults and school-aged children use norm-based coding for face identity but it is not yet known if pre-school aged children also use norm-based coding. We reasoned that the transition to school could be critical in developing a norm-based system because school places new demands on children's face identification skills and substantially increases experience with faces. Consistent with this view, face identification performance improves steeply between ages 4 and 7. We used face identity aftereffects to test whether norm-based coding emerges between these ages. We found that 4 year-old children, like adults, showed larger face identity aftereffects for adaptors far from the average than for adaptors closer to the average, consistent with use of norm-based coding. We conclude that experience prior to age 4 is sufficient to develop a norm-based face-space and that failure to use norm-based coding cannot explain 4 year-old children's poor face identification skills. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Development and testing of the Youth Alcohol Norms Survey (YANS) instrument to measure youth alcohol norms and psychosocial influences

    PubMed Central

    Maycock, Bruce; Hildebrand, Janina; Zhao, Yun; Allsop, Steve; Lobo, Roanna; Howat, Peter

    2018-01-01

    Objectives This study aimed to develop and validate an online instrument to: (1) identify common alcohol-related social influences, norms and beliefs among adolescents; (2) clarify the process and pathways through which proalcohol norms are transmitted to adolescents; (3) describe the characteristics of social connections that contribute to the transmission of alcohol norms; and (4) identify the influence of alcohol marketing on adolescent norm development. Setting The online Youth Alcohol Norms Survey (YANS) was administered in secondary schools in Western Australia Participants Using a 2-week test–retest format, the YANS was administered to secondary school students (n=481, age=13–17 years, female 309, 64.2%). Primary and secondary outcome measures The development of the YANS was guided by social cognitive theory and comprised a systematic multistage process including evaluation of content and face validity. A 2-week test–retest format was employed. Exploratory factor analysis was conducted to determine the underlying factor structure of the instrument. Test–retest reliability was examined using intraclass correlation coefficient (ICC) and Cohen’s kappa. Results A five-factor structure with meaningful components and robust factorial loads was identified, and the five factors were labelled as ‘individual attitudes and beliefs’, ‘peer and community identity’, ‘sibling influences’, ‘school and community connectedness’ and ‘injunctive norms’, respectively. The instrument demonstrated stability across the test–retest procedure (ICC=0.68–0.88, Cohen’s kappa coefficient=0.69) for most variables. Conclusions The results support the reliability and factorial validity of this instrument. The YANS presents a promising tool, which enables comprehensive assessment of reciprocal individual, behavioural and environmental factors that influence alcohol-related norms among adolescents. PMID:29764872

  1. Ethnic diversity, traditional norms, and marriage behaviour in Indonesia.

    PubMed

    Buttenheim, Alison M; Nobles, Jenna

    2009-11-01

    What role do cultural norms play in shaping individual behaviour and how does this relationship change with rapid socio-economic development? While modernization and convergence theories predict a weakened relationship between culture and behaviour as individuals rely less on family and community members for economic opportunities, recent research suggests that such norms can persist and continue to influence behaviour. We explored this question for Indonesia, asking whether cultural norms for age at marriage and post-marriage residence-as embodied in local ethnicity-based laws and customs known as 'adat'-relate to actual marriage behaviour. We demonstrate that adat norms are strong predictors of marriage behaviour, both over time and net of large increases in educational attainment. Our results suggest more generally that traditional marriage norms can persist even when a society is in the process of rapid socio-economic development.

  2. Mortality salience increases personal relevance of the norm of reciprocity.

    PubMed

    Schindler, Simon; Reinhard, Marc-André; Stahlberg, Dagmar

    2012-10-01

    Research on terror management theory found evidence that people under mortality salience strive to live up to salient cultural norms and values, like egalitarianism, pacifism, or helpfulness. A basic, strongly internalized norm in most human societies is the norm of reciprocity: people should support those who supported them (i.e., positive reciprocity), and people should injure those who injured them (i.e., negative reciprocity), respectively. In an experiment (N = 98; 47 women, 51 men), mortality salience overall significantly increased personal relevance of the norm of reciprocity (M = 4.45, SD = 0.65) compared to a control condition (M = 4.19, SD = 0.59). Specifically, under mortality salience there was higher motivation to punish those who treated them unfavourably (negative norm of reciprocity). Unexpectedly, relevance of the norm of positive reciprocity remained unaffected by mortality salience. Implications and limitations are discussed.

  3. Prosocial norms as a positive youth development construct: a conceptual review.

    PubMed

    Siu, Andrew M H; Shek, Daniel T L; Law, Ben

    2012-01-01

    Prosocial norms like reciprocity, social responsibility, altruism, and volunteerism are ethical standards and beliefs that youth development programs often want to promote. This paper reviews evolutionary, social-cognitive, and developmental theories of prosocial development and analyzes how young people learn and adopt prosocial norms. The paper showed that very few current theories explicitly address the issue of how prosocial norms, in form of feelings of moral obligations, may be challenged by a norm of self-interest and social circumstances when prosocial acts are needed. It is necessary to develop theories which put prosocial norms as a central construct, and a new social cognitive theory of norm activation has the potential to help us understand how prosocial norms may be applied. This paper also highlights how little we know about young people perceiving and receiving prosocial norms and how influential of school policies and peer influence on the prosocial development. Lastly, while training of interpersonal competence (e.g., empathy, moral reasoning, etc.) was commonly used in the youth development, their effectiveness was not systematically evaluated. It will also be interesting to examine how computer and information technology or video games may be used in e-learning of prosocial norms.

  4. Not just the norm: exemplar-based models also predict face aftereffects.

    PubMed

    Ross, David A; Deroche, Mickael; Palmeri, Thomas J

    2014-02-01

    The face recognition literature has considered two competing accounts of how faces are represented within the visual system: Exemplar-based models assume that faces are represented via their similarity to exemplars of previously experienced faces, while norm-based models assume that faces are represented with respect to their deviation from an average face, or norm. Face identity aftereffects have been taken as compelling evidence in favor of a norm-based account over an exemplar-based account. After a relatively brief period of adaptation to an adaptor face, the perceived identity of a test face is shifted toward a face with attributes opposite to those of the adaptor, suggesting an explicit psychological representation of the norm. Surprisingly, despite near universal recognition that face identity aftereffects imply norm-based coding, there have been no published attempts to simulate the predictions of norm- and exemplar-based models in face adaptation paradigms. Here, we implemented and tested variations of norm and exemplar models. Contrary to common claims, our simulations revealed that both an exemplar-based model and a version of a two-pool norm-based model, but not a traditional norm-based model, predict face identity aftereffects following face adaptation.

  5. Not Just the Norm: Exemplar-Based Models also Predict Face Aftereffects

    PubMed Central

    Ross, David A.; Deroche, Mickael; Palmeri, Thomas J.

    2014-01-01

    The face recognition literature has considered two competing accounts of how faces are represented within the visual system: Exemplar-based models assume that faces are represented via their similarity to exemplars of previously experienced faces, while norm-based models assume that faces are represented with respect to their deviation from an average face, or norm. Face identity aftereffects have been taken as compelling evidence in favor of a norm-based account over an exemplar-based account. After a relatively brief period of adaptation to an adaptor face, the perceived identity of a test face is shifted towards a face with opposite attributes to the adaptor, suggesting an explicit psychological representation of the norm. Surprisingly, despite near universal recognition that face identity aftereffects imply norm-based coding, there have been no published attempts to simulate the predictions of norm- and exemplar-based models in face adaptation paradigms. Here we implemented and tested variations of norm and exemplar models. Contrary to common claims, our simulations revealed that both an exemplar-based model and a version of a two-pool norm-based model, but not a traditional norm-based model, predict face identity aftereffects following face adaptation. PMID:23690282

  6. CLEX: A Cross-Linguistic Lexical Norms Database

    ERIC Educational Resources Information Center

    Jorgensen, Rune Norgaard; Dale, Philip S.; Bleses, Dorthe; Fenson, Larry

    2010-01-01

    Parent report has proven a valid and cost-effective means of evaluating early child language. Norming datasets for these instruments, which provide the basis for standardized comparisons of individual children to a population, can also be used to derive norms for the acquisition of individual words in production and comprehension and also early…

  7. Alcohol evaluations and acceptability: Examining descriptive and injunctive norms among heavy drinkers

    PubMed Central

    Foster, Dawn W.; Neighbors, Clayton; Krieger, Heather

    2015-01-01

    Objectives This study assessed descriptive and injunctive norms, evaluations of alcohol consequences, and acceptability of drinking. Methods Participants were 248 heavy-drinking undergraduates (81.05% female; Mage = 23.45). Results Stronger perceptions of descriptive and injunctive norms for drinking and more positive evaluations of alcohol consequences were positively associated with drinking and the number of drinks considered acceptable. Descriptive and injunctive norms interacted, indicating that injunctive norms were linked with number of acceptable drinks among those with higher descriptive norms. Descriptive norms and evaluations of consequences interacted, indicating that descriptive norms were positively linked with number of acceptable drinks among those with negative evaluations of consequences; however, among those with positive evaluations of consequences, descriptive norms were negatively associated with number of acceptable drinks. Injunctive norms and evaluations of consequences interacted, indicating that injunctive norms were positively associated with number of acceptable drinks, particularly among those with positive evaluations of consequences. A three-way interaction emerged between injunctive and descriptive norms and evaluations of consequences, suggesting that injunctive norms and the number of acceptable drinks were positively associated more strongly among those with negative versus positive evaluations of consequences. Those with higher acceptable drinks also had positive evaluations of consequences and were high in injunctive norms. Conclusions Findings supported hypotheses that norms and evaluations of alcohol consequences would interact with respect to drinking and acceptance of drinking. These examinations have practical utility and may inform development and implementation of interventions and programs targeting alcohol misuse among heavy drinking undergraduates. PMID:25437265

  8. Changing Norms to Change Behavior.

    PubMed

    Miller, Dale T; Prentice, Deborah A

    2016-01-01

    Providing people with information about the behavior and attitudes of their peers is a strategy commonly employed by those seeking to reduce behavior deemed harmful either to individuals (e.g., high alcohol consumption) or the collective (e.g., high energy consumption). We review norm-based interventions, detailing the logic behind them and the various forms they can take. We give special attention to interventions designed to decrease college students' drinking and increase environment-friendly behaviors. We identify the conditions under which norm information has the highest likelihood of changing the targeted behavior and discuss why this is the case.

  9. Indirect iterative learning control for a discrete visual servo without a camera-robot model.

    PubMed

    Jiang, Ping; Bamforth, Leon C A; Feng, Zuren; Baruch, John E F; Chen, YangQuan

    2007-08-01

    This paper presents a discrete learning controller for vision-guided robot trajectory imitation with no prior knowledge of the camera-robot model. A teacher demonstrates a desired movement in front of a camera, and then, the robot is tasked to replay it by repetitive tracking. The imitation procedure is considered as a discrete tracking control problem in the image plane, with an unknown and time-varying image Jacobian matrix. Instead of updating the control signal directly, as is usually done in iterative learning control (ILC), a series of neural networks are used to approximate the unknown Jacobian matrix around every sample point in the demonstrated trajectory, and the time-varying weights of local neural networks are identified through repetitive tracking, i.e., indirect ILC. This makes repetitive segmented training possible, and a segmented training strategy is presented to retain the training trajectories solely within the effective region for neural network approximation. However, a singularity problem may occur if an unmodified neural-network-based Jacobian estimation is used to calculate the robot end-effector velocity. A new weight modification algorithm is proposed which ensures invertibility of the estimation, thus circumventing the problem. Stability is further discussed, and the relationship between the approximation capability of the neural network and the tracking accuracy is obtained. Simulations and experiments are carried out to illustrate the validity of the proposed controller for trajectory imitation of robot manipulators with unknown time-varying Jacobian matrices.

  10. Rational Approximations with Hankel-Norm Criterion

    DTIC Science & Technology

    1980-01-01

    REPORT TYPE ANDu DATES COVERED It) L. TITLE AND SLWUIlL Fi901 ia FUNDING NUMOIRS, RATIONAL APPROXIMATIONS WITH HANKEL-NORM CRITERION PE61102F i...problem is proved to be reducible to obtain a two-variable all- pass ration 1 function, interpolating a set of parametric values at specified points inside...PAGES WHICH DO NOT REPRODUCE LEGIBLY. V" C - w RATIONAL APPROXIMATIONS WITH HANKEL-NORM CRITERION* Y. Genin* Philips Research Lab. 2, avenue van

  11. Adults' Attitudes about Children's Gender Norm Transgressions.

    ERIC Educational Resources Information Center

    Blakemore, Judith E. Owen

    This study examined college students' knowledge and attitudes regarding children's gender, and social and moral norms, and compared their evaluations of violation of each norm type. Participating were 140 female and 67 male college students ranging in age from 17 to 46 years, 33 of whom were parents. Subjects were asked questions related to toys,…

  12. Positive Community Norm Survey 2011 : Methodology and Results

    DOT National Transportation Integrated Search

    2012-09-01

    This survey established a baseline understanding of the positive norms that exist in Idaho, plus reveal the gaps in knowledge and perceived norms with regard to impaired driving. These gaps will indicate the most effective opportunities for future co...

  13. Positive Community Norm Survey 2011: Methodology and Results

    DOT National Transportation Integrated Search

    2012-09-01

    This survey established a baseline understanding of the positive norms that exist in Idaho, plus reveal the gaps in knowledge and perceived norms with regard to impaired driving. These gaps will indicate the most effective opportunities for future co...

  14. Prosocial Norms as a Positive Youth Development Construct: A Conceptual Review

    PubMed Central

    Siu, Andrew M. H.; Shek, Daniel T. L.; Law, Ben

    2012-01-01

    Prosocial norms like reciprocity, social responsibility, altruism, and volunteerism are ethical standards and beliefs that youth development programs often want to promote. This paper reviews evolutionary, social-cognitive, and developmental theories of prosocial development and analyzes how young people learn and adopt prosocial norms. The paper showed that very few current theories explicitly address the issue of how prosocial norms, in form of feelings of moral obligations, may be challenged by a norm of self-interest and social circumstances when prosocial acts are needed. It is necessary to develop theories which put prosocial norms as a central construct, and a new social cognitive theory of norm activation has the potential to help us understand how prosocial norms may be applied. This paper also highlights how little we know about young people perceiving and receiving prosocial norms and how influential of school policies and peer influence on the prosocial development. Lastly, while training of interpersonal competence (e.g., empathy, moral reasoning, etc.) was commonly used in the youth development, their effectiveness was not systematically evaluated. It will also be interesting to examine how computer and information technology or video games may be used in e-learning of prosocial norms. PMID:22666157

  15. The Social Norms of Suicidal and Self-Harming Behaviours in Scottish Adolescents.

    PubMed

    Quigley, Jody; Rasmussen, Susan; McAlaney, John

    2017-03-15

    Although the suicidal and self-harming behaviour of individuals is often associated with similar behaviours in people they know, little is known about the impact of perceived social norms on those behaviours. In a range of other behavioural domains (e.g., alcohol consumption, smoking, eating behaviours) perceived social norms have been found to strongly predict individuals' engagement in those behaviours, although discrepancies often exist between perceived and reported norms. Interventions which align perceived norms more closely with reported norms have been effective in reducing damaging behaviours. The current study aimed to explore whether the Social Norms Approach is applicable to suicidal and self-harming behaviours in adolescents. Participants were 456 pupils from five Scottish high-schools (53% female, mean age = 14.98 years), who completed anonymous, cross-sectional surveys examining reported and perceived norms around suicidal and self-harming behaviour. Friedman's ANOVA with post-hoc Wilcoxen signed-ranks tests indicated that proximal groups were perceived as less likely to engage in or be permissive of suicidal and self-harming behaviours than participants' reported themselves, whilst distal groups tended towards being perceived as more likely to do so. Binary logistic regression analyses identified a number of perceived norms associated with reported norms, with close friends' norms positively associated with all outcome variables. The Social Norms Approach may be applicable to suicidal and self-harming behaviour, but associations between perceived and reported norms and predictors of reported norms differ to those found in other behavioural domains. Theoretical and practical implications of the findings are considered.

  16. The Social Norms of Suicidal and Self-Harming Behaviours in Scottish Adolescents

    PubMed Central

    Quigley, Jody; Rasmussen, Susan; McAlaney, John

    2017-01-01

    Although the suicidal and self-harming behaviour of individuals is often associated with similar behaviours in people they know, little is known about the impact of perceived social norms on those behaviours. In a range of other behavioural domains (e.g., alcohol consumption, smoking, eating behaviours) perceived social norms have been found to strongly predict individuals’ engagement in those behaviours, although discrepancies often exist between perceived and reported norms. Interventions which align perceived norms more closely with reported norms have been effective in reducing damaging behaviours. The current study aimed to explore whether the Social Norms Approach is applicable to suicidal and self-harming behaviours in adolescents. Participants were 456 pupils from five Scottish high-schools (53% female, mean age = 14.98 years), who completed anonymous, cross-sectional surveys examining reported and perceived norms around suicidal and self-harming behaviour. Friedman’s ANOVA with post-hoc Wilcoxen signed-ranks tests indicated that proximal groups were perceived as less likely to engage in or be permissive of suicidal and self-harming behaviours than participants’ reported themselves, whilst distal groups tended towards being perceived as more likely to do so. Binary logistic regression analyses identified a number of perceived norms associated with reported norms, with close friends’ norms positively associated with all outcome variables. The Social Norms Approach may be applicable to suicidal and self-harming behaviour, but associations between perceived and reported norms and predictors of reported norms differ to those found in other behavioural domains. Theoretical and practical implications of the findings are considered. PMID:28294999

  17. Computational Substrates of Social Norm Enforcement by Unaffected Third Parties

    PubMed Central

    Zhong, Songfa; Chark, Robin; Hsu, Ming; Chew, Soo Hong

    2016-01-01

    Enforcement of social norms by impartial bystanders in the human species reveals a possibly unique capacity to sense and to enforce norms from a third party perspective. Such behavior, however, cannot be accounted by current computational models based on an egocentric notion of norms. Here, using a combination of model-based fMRI and third party punishment games, we show that brain regions previously implicated in egocentric norm enforcement critically extend to the important case of norm enforcement by unaffected third parties. Specifically, we found that responses in the ACC and insula cortex were positively associated with detection of distributional inequity, while those in the anterior DLPFC were associated with assessment of intentionality to the violator. Moreover, during sanction decisions, the subjective value of sanctions modulated activity in both vmPFC and rTPJ. These results shed light on the neurocomputational underpinnings of third party punishment and evolutionary origin of human norm enforcement. PMID:26825438

  18. Computational substrates of social norm enforcement by unaffected third parties.

    PubMed

    Zhong, Songfa; Chark, Robin; Hsu, Ming; Chew, Soo Hong

    2016-04-01

    Enforcement of social norms by impartial bystanders in the human species reveals a possibly unique capacity to sense and to enforce norms from a third party perspective. Such behavior, however, cannot be accounted by current computational models based on an egocentric notion of norms. Here, using a combination of model-based fMRI and third party punishment games, we show that brain regions previously implicated in egocentric norm enforcement critically extend to the important case of norm enforcement by unaffected third parties. Specifically, we found that responses in the ACC and insula cortex were positively associated with detection of distributional inequity, while those in the anterior DLPFC were associated with assessment of intentionality to the violator. Moreover, during sanction decisions, the subjective value of sanctions modulated activity in both vmPFC and rTPJ. These results shed light on the neurocomputational underpinnings of third party punishment and evolutionary origin of human norm enforcement. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Toleration and the Design of Norms.

    PubMed

    Floridi, Luciano

    2015-10-01

    One of the pressing challenges we face today-in a post-Westphalian order (emergence of the state as the modern, political information agent) and post-Bretton Woods world (emergence of non-state multiagent systems or MASs as "hyperhistorical" players in the global economy and politics)-is how to design the right kind of MAS that can take full advantage of the socio-economic and political progress made so far, while dealing successfully with the new global challenges that are undermining the best legacy of that very progress. This is the topic of the article. In it, I argue that (i) in order to design the right kind of MAS, we need to design the right kind of norms that constitute them; (ii) in order to design the right kind of constitutive norms, we need to identify and adopt the right kind of principles of normative design; (iii) toleration is one of those principles; (iv) unfortunately, its role as a foundation for the design of norms has been undermined by the "paradox of toleration"; (v) however, the paradox can be solved; (vi) so toleration can be re-instated as the right kind of foundational principle for the design of the right kind of norms that can constitute the right kind of MAS that can operate across cultures, societies and states, to help us to tackle the new global challenges facing us.

  20. Privacy, technology, and norms: the case of Smart Meters.

    PubMed

    Horne, Christine; Darras, Brice; Bean, Elyse; Srivastava, Anurag; Frickel, Scott

    2015-05-01

    Norms shift and emerge in response to technological innovation. One such innovation is Smart Meters - components of Smart Grid energy systems capable of minute-to-minute transmission of consumer electricity use information. We integrate theory from sociological research on social norms and privacy to examine how privacy threats affect the demand for and expectations of norms that emerge in response to new technologies, using Smart Meters as a test case. Results from three vignette experiments suggest that increased threats to privacy created by Smart Meters are likely to provoke strong demand for and expectations of norms opposing the technology and that the strength of these normative rules is at least partly conditional on the context. Privacy concerns vary little with actors' demographic characteristics. These findings contribute to theoretical understanding of norm emergence and have practical implications for implementing privacy protections that effectively address concerns of electricity users. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Improved Quasi-Newton method via PSB update for solving systems of nonlinear equations

    NASA Astrophysics Data System (ADS)

    Mamat, Mustafa; Dauda, M. K.; Waziri, M. Y.; Ahmad, Fadhilah; Mohamad, Fatma Susilawati

    2016-10-01

    The Newton method has some shortcomings which includes computation of the Jacobian matrix which may be difficult or even impossible to compute and solving the Newton system in every iteration. Also, the common setback with some quasi-Newton methods is that they need to compute and store an n × n matrix at each iteration, this is computationally costly for large scale problems. To overcome such drawbacks, an improved Method for solving systems of nonlinear equations via PSB (Powell-Symmetric-Broyden) update is proposed. In the proposed method, the approximate Jacobian inverse Hk of PSB is updated and its efficiency has improved thereby require low memory storage, hence the main aim of this paper. The preliminary numerical results show that the proposed method is practically efficient when applied on some benchmark problems.

  2. Norm stability at Alcatraz Island: Effects of time and changing conditions

    Treesearch

    William Valliere; Robert Manning

    2010-01-01

    Research suggests that visitors often have norms about the resource and social conditions acceptable in a park and that understanding such norms can be useful for park management. Most studies of norms use data from cross-sectional surveys, and little is known about how norms may change over time. To explore this issue, we conducted a study in 2007 to determine whether...

  3. Social norms of accompanied young children and observed crossing behaviors.

    PubMed

    Rosenbloom, Tova; Sapir-Lavid, Yael; Hadari-Carmi, Ofri

    2009-01-01

    Social norms for accompanied young children and crossing behaviors were examined in two studies conducted in an Ultra-Orthodox Jewish community in Israel. In Study 1, road behaviors of young children crossing with and without accompaniment and older children were observed, and the actual social norm for accompanied school children younger than 9-years-old was examined. In Study 2, the perceived norm of accompaniment was tested by questionnaires. Young children who crossed without accompaniment exhibited poorer crossing skills compared to older children and to young children crossing with accompaniment. In the four locations observed, the actual accompaniment rate ranged between 15%-60%. The perceived social norm for child accompaniment was lower than the actual norm. The discussion refers to both theoretical issues and their practical implications.

  4. Norm, gender, and bribe-giving: Insights from a behavioral game.

    PubMed

    Lan, Tian; Hong, Ying-Yi

    2017-01-01

    Previous research has suggested that bribery is more normative in some countries than in others. To understand the underlying process, this paper examines the effects of social norm and gender on bribe-giving behavior. We argue that social norms provide information for strategic planning and impression management, and thus would impact participants' bribe amount. Besides, males are more agentic and focus more on impression management than females. We predicted that males would defy the norm in order to win when the amount of their bribe was kept private, but would conform to the norm when it was made public. To test this hypothesis, we conducted two studies using a competitive game. In each game, we asked three participants to compete in five rounds of creative tasks, and the winner was determined by a referee's subjective judgment of the participants' performance on the tasks. Participants were allowed to give bribes to the referee. Bribe-giving norms were manipulated in two domains: norm level (high vs. low) and norm context (private vs. public), in order to investigate the influence of informational and affiliational needs. Studies 1 and 2 consistently showed that individuals conformed to the norm level of bribe-giving while maintaining a relative advantage for economic benefit. Study 2 found that males gave larger bribes in the private context than in the public, whereas females gave smaller bribes in both contexts. We used a latent growth curve model (LGCM) to depict the development of bribe-giving behaviors during five rounds of competition. The results showed that gender, creative performance, and norm level all influence the trajectory of bribe-giving behavior.

  5. Norm, gender, and bribe-giving: Insights from a behavioral game

    PubMed Central

    Hong, Ying-yi

    2017-01-01

    Previous research has suggested that bribery is more normative in some countries than in others. To understand the underlying process, this paper examines the effects of social norm and gender on bribe-giving behavior. We argue that social norms provide information for strategic planning and impression management, and thus would impact participants’ bribe amount. Besides, males are more agentic and focus more on impression management than females. We predicted that males would defy the norm in order to win when the amount of their bribe was kept private, but would conform to the norm when it was made public. To test this hypothesis, we conducted two studies using a competitive game. In each game, we asked three participants to compete in five rounds of creative tasks, and the winner was determined by a referee’s subjective judgment of the participants’ performance on the tasks. Participants were allowed to give bribes to the referee. Bribe-giving norms were manipulated in two domains: norm level (high vs. low) and norm context (private vs. public), in order to investigate the influence of informational and affiliational needs. Studies 1 and 2 consistently showed that individuals conformed to the norm level of bribe-giving while maintaining a relative advantage for economic benefit. Study 2 found that males gave larger bribes in the private context than in the public, whereas females gave smaller bribes in both contexts. We used a latent growth curve model (LGCM) to depict the development of bribe-giving behaviors during five rounds of competition. The results showed that gender, creative performance, and norm level all influence the trajectory of bribe-giving behavior. PMID:29272291

  6. Predicting negative drinking consequences: examining descriptive norm perception.

    PubMed

    Benton, Stephen L; Downey, Ronald G; Glider, Peggy S; Benton, Sherry A; Shin, Kanghyun; Newton, Douglas W; Arck, William; Price, Amy

    2006-05-01

    This study explored how much variance in college student negative drinking consequences is explained by descriptive norm perception, beyond that accounted for by student gender and self-reported alcohol use. A derivation sample (N=7565; 54% women) and a replication sample (N=8924; 55.5% women) of undergraduate students completed the Campus Alcohol Survey in classroom settings. Hierarchical regression analyses revealed that student gender and average number of drinks when "partying" were significantly related to harmful consequences resulting from drinking. Men reported more consequences than did women, and drinking amounts were positively correlated with consequences. However, descriptive norm perception did not explain any additional variance beyond that attributed to gender and alcohol use. Furthermore, there was no significant three-way interaction among student gender, alcohol use, and descriptive norm perception. Norm perception contributed no significant variance in explaining harmful consequences beyond that explained by college student gender and alcohol use.

  7. Development, social norms, and assignment to task

    PubMed Central

    Fafchamps, Marcel

    2011-01-01

    Economic development involves a structural transformation in the way people are allocated to tasks. There is a shift from self-provision to market exchange, facilitating specialization. There is also a shift from self-employment to wage employment in large firms and organizations, driven by innovation and increasing returns to scale. Changes in allocation mechanisms require changes in norms and attitudes. Because different labor assignment domains coexist, conflicts arise among norms that apply to different domains, possibly resulting in dysfunctional outcomes. I argue that religion, humanism, and schools have all played an important historical role in fostering the changes in social norms and attitudes that are needed to accompany structural changes in the way economies allocate workers to tasks. PMID:22198757

  8. Diversity-induced resonance in the response to social norms

    NASA Astrophysics Data System (ADS)

    Tessone, Claudio J.; Sánchez, Angel; Schweitzer, Frank

    2013-02-01

    In this paper we focus on diversity-induced resonance, which was recently found in bistable, excitable, and other physical systems. We study the appearance of this phenomenon in a purely economic model of cooperating and defecting agents. An agent's contribution to a public good is seen as a social norm, so defecting agents face a social pressure, which decreases if free riding becomes widespread. In this model, diversity among agents naturally appears because of the different sensitivities towards the social norm. We study the evolution of cooperation as a response to the social norm (i) for the replicator dynamics and (ii) for the logit dynamics by means of numerical simulations. Diversity-induced resonance is observed as a maximum in the response of agents to changes in the social norm as a function of the degree of heterogeneity in the population. We provide an analytical, mean-field approach for the logit dynamics and find very good agreement with the simulations. From a socioeconomic perspective, our results show that, counterintuitively, diversity in the individual sensitivity to social norms may result in a society that better follows such norms as a whole, even if part of the population is less prone to follow them.

  9. On the Normed Space of Equivalence Classes of Fuzzy Numbers

    PubMed Central

    Lu, Chongxia; Zhang, Wei

    2013-01-01

    We study the norm induced by the supremum metric on the space of fuzzy numbers. And then we propose a method for constructing a norm on the quotient space of fuzzy numbers. This norm is very natural and works well with the induced metric on the quotient space. PMID:24072984

  10. Computational substrates of norms and their violations during social exchange.

    PubMed

    Xiang, Ting; Lohrenz, Terry; Montague, P Read

    2013-01-16

    Social norms in humans constrain individual behaviors to establish shared expectations within a social group. Previous work has probed social norm violations and the feelings that such violations engender; however, a computational rendering of the underlying neural and emotional responses has been lacking. We probed norm violations using a two-party, repeated fairness game (ultimatum game) where proposers offer a split of a monetary resource to a responder who either accepts or rejects the offer. Using a norm-training paradigm where subject groups are preadapted to either high or low offers, we demonstrate that unpredictable shifts in expected offers creates a difference in rejection rates exhibited by the two responder groups for otherwise identical offers. We constructed an ideal observer model that identified neural correlates of norm prediction errors in the ventral striatum and anterior insula, regions that also showed strong responses to variance-prediction errors generated by the same model. Subjective feelings about offers correlated with these norm prediction errors, and the two signals displayed overlapping, but not identical, neural correlates in striatum, insula, and medial orbitofrontal cortex. These results provide evidence for the hypothesis that responses in anterior insula can encode information about social norm violations that correlate with changes in overt behavior (changes in rejection rates). Together, these results demonstrate that the brain regions involved in reward prediction and risk prediction are also recruited in signaling social norm violations.

  11. Computational Substrates of Norms and Their Violations during Social Exchange

    PubMed Central

    Xiang, Ting; Lohrenz, Terry; Montague, P. Read

    2013-01-01

    Social norms in humans constrain individual behaviors to establish shared expectations within a social group. Previous work has probed social norm violations and the feelings that such violations engender; however, a computational rendering of the underlying neural and emotional responses has been lacking. We probed norm violations using a two-party, repeated fairness game (ultimatum game) where proposers offer a split of a monetary resource to a responder who either accepts or rejects the offer. Using a norm-training paradigm where subject groups are preadapted to either high or low offers, we demonstrate that unpredictable shifts in expected offers creates a difference in rejection rates exhibited by the two responder groups for otherwise identical offers. We constructed an ideal observer model that identified neural correlates of norm prediction errors in the ventral striatum and anterior insula, regions that also showed strong responses to variance-prediction errors generated by the same model. Subjective feelings about offers correlated with these norm prediction errors, and the two signals displayed overlapping, but not identical, neural correlates in striatum, insula, and medial orbitofrontal cortex. These results provide evidence for the hypothesis that responses in anterior insula can encode information about social norm violations that correlate with changes in overt behavior (changes in rejection rates). Together, these results demonstrate that the brain regions involved in reward prediction and risk prediction are also recruited in signaling social norm violations. PMID:23325247

  12. Clinical ethics and values: how do norms evolve from practice?

    PubMed

    Spranzi, Marta

    2013-02-01

    Bioethics laws in France have just undergone a revision process. The bioethics debate is often cast in terms of ethical principles and norms resisting emerging social and technological practices. This leads to the expression of confrontational attitudes based on widely differing interpretations of the same principles and values, and ultimately results in a deadlock. In this paper I would like to argue that focusing on values, as opposed to norms and principles, provides an interesting perspective on the evolution of norms. As Joseph Raz has convincingly argued, "life-building" values and practices are closely intertwined. Precisely because values have a more indeterminate meaning than norms, they can be cited as reasons for action by concerned stakeholders, and thus can help us understand how controversial practices, e.g. surrogate motherhood, can be justified. Finally, norms evolve when the interpretations of the relevant values shift and cause a change in the presumptions implicit in the norms. Thus, norms are not a prerequisite of the ethical solution of practical dilemmas, but rather the outcome of the decision-making process itself. Struggling to reach the right decision in controversial clinical ethics situations indirectly causes social and moral values to change and principles to be understood differently.

  13. Clarifying the contribution of subjective norm to predicting leisure-time exercise.

    PubMed

    Okun, Morris A; Karoly, Paul; Lutz, Rafer

    2002-01-01

    To clarify the contribution of subjective norm to exercise intention and behavior by considering the influence of descriptive as well as injunctive social norms related to family and friends. A sample of 530 college students completed a questionnaire that assessed descriptive and injunctive social norms related to family and to friends, perceived behavioral control, attitude, intention, and leisure-time exercise. Friend descriptive social norm was a significant predictor of both intention (p<.05) and leisure-time exercise (p<.001). Descriptive norms should be incorporated into tests of the theory of planned behavior in the exercise domain.

  14. Control of NORM at Eugene Island 341-A

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shuler, P.J.; Baudoin, D.A.; Weintritt, D.J.

    1995-12-31

    A field study at Eugene island 341-A, an offshore production platform in the Gulf of Mexico, was conducted to develop strategies for the cost-effective prevention of NORM (Naturally Occurring Radioactive Materials) deposits. The specific objectives of this study were to: (1) Determine the root cause for the NORM deposits at this facility, utilizing different diagnostic techniques. (2) Consider all engineering options that are designed to prevent NORM from forming. (3) Determine the most cost-effective engineering solution. An overall objective was to generalize the diagnostics and control methods developed for Eugene Island 341-A to other oil and gas production facilities, especiallymore » to platforms located in the Gulf of Mexico. This study determined that the NORM deposits found at Eugene Island 341-A stem from commingling incompatible produced waters at the surface. Wells completed in Sand Block A have a water containing a relatively high concentration of barium, while those formation brines in Sand Blocks B and C are high in sulfate. When these waters mix at the start of the fluid treatment facilities on the platform, barium sulfate forms. Radium that is present in the produced brines co-precipitates with the barium, thereby creating a radioactive barium sulfate scale deposit (NORM).« less

  15. The Role of Values, Moral Norms, and Descriptive Norms in Building Occupant Responses to an Energy-Efficiency Pilot Program and to Framing of Related Messages

    ERIC Educational Resources Information Center

    Arpan, Laura M.; Barooah, Prabir; Subramany, Rahul

    2015-01-01

    This study examined building occupants' responses associated with an occupant-based energy-efficiency pilot in a university building. The influence of occupants' values and norms as well as effects of two educational message frames (descriptive vs. moral norms cues) on program support were tested. Occupants' personal moral norm to conserve energy…

  16. Cyber Norms for Civilian Nuclear Power Plants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Spirito, Christopher

    The international community agrees that the safe operation of civilian nuclear infrastructure is in every population’s best interest. One challenge each government must address is defining and agreeing to a set of acceptable norms of behavior in cyberspace as they relate to these facilities. The introduction of digital systems and networking technologies into these environments has led to the possibility that control and supporting computer systems are now accessible and exploitable, especially where interconnections to global information and communications technology (ICT) networks exist. The need for norms of behavior in cyberspace includes what is expected of system architects and cybermore » defenders as well as adversaries who should abide by rules of engagement even while conducting acts that violate national and international laws. The goal of this paper is to offer three behavioral cyber norms to improve the overall security of the ICT and Operational Technology (OT) networks and systems that underlie the operations of nuclear facilities. These norms of behavior will be specifically defined with the goals of reducing the threats associated to the theft of nuclear materials, accidental release of radiation and sabotage of nuclear processes. These norms would also include instances where an unwitting attacker or intelligence collection entity inadvertently makes their way into a nuclear facility network or system and can recognize they are in a protected zone and an approach to ensuring that these zones are not exploitable by bad actors to place their sensitive cyber effect delivery systems.« less

  17. The Maturation of Norms for Computer-Mediated Communication.

    ERIC Educational Resources Information Center

    Newby, Gregory B.

    1993-01-01

    Analyzes the communication norms of the major forms of computer-mediated communication, including electronic mail, mailing lists, Usenet and other bulletin board systems, interactive messaging, multiuser domains (MUDs), and mass-broadcast media. New uses and the development of standards, or norms, are discussed. (Contains 11 references.) (LRW)

  18. Oral-diadochokinesis rates across languages: English and Hebrew norms.

    PubMed

    Icht, Michal; Ben-David, Boaz M

    2014-01-01

    Oro-facial and speech motor control disorders represent a variety of speech and language pathologies. Early identification of such problems is important and carries clinical implications. A common and simple tool for gauging the presence and severity of speech motor control impairments is oral-diadochokinesis (oral-DDK). Surprisingly, norms for adult performance are missing from the literature. The goals of this study were: (1) to establish a norm for oral-DDK rate for (young to middle-age) adult English speakers, by collecting data from the literature (five studies, N=141); (2) to investigate the possible effect of language (and culture) on oral-DDK performance, by analyzing studies conducted in other languages (five studies, N=140), alongside the English norm; and (3) to find a new norm for adult Hebrew speakers, by testing 115 speakers. We first offer an English norm with a mean of 6.2syllables/s (SD=.8), and a lower boundary of 5.4syllables/s that can be used to indicate possible abnormality. Next, we found significant differences between four tested languages (English, Portuguese, Farsi and Greek) in oral-DDK rates. Results suggest the need to set language and culture sensitive norms for the application of the oral-DDK task world-wide. Finally, we found the oral-DDK performance for adult Hebrew speakers to be 6.4syllables/s (SD=.8), not significantly different than the English norms. This implies possible phonological similarities between English and Hebrew. We further note that no gender effects were found in our study. We recommend using oral-DDK as an important tool in the speech language pathologist's arsenal. Yet, application of this task should be done carefully, comparing individual performance to a set norm within the specific language. Readers will be able to: (1) identify the Speech-Language Pathologist assessment process using the oral-DDK task, by comparing an individual performance to the present English norm, (2) describe the impact of language

  19. Computer-Delivered Social Norm Message Increases Pain Tolerance

    PubMed Central

    Pulvers, Kim; Schroeder, Jacquelyn; Limas, Eleuterio F.; Zhu, Shu-Hong

    2013-01-01

    Background Few experimental studies have been conducted on social determinants of pain tolerance. Purpose This study tests a brief, computer-delivered social norm message for increasing pain tolerance. Methods Healthy young adults (N=260; 44 % Caucasian; 27 % Hispanic) were randomly assigned into a 2 (social norm)×2 (challenge) cold pressor study, stratified by gender. They received standard instructions or standard instructions plus a message that contained artifically elevated information about typical performance of others. Results Those receiving a social norm message displayed significantly higher pain tolerance, F(1, 255)=26.95, p<.001, ηp2=.10 and pain threshold F(1, 244)=9.81, p=.002, ηp2=.04, but comparable pain intensity, p>.05. There were no interactions between condition and gender on any outcome variables, p>.05. Conclusions Social norms can significantly increase pain tolerance, even with a brief verbal message delivered by a video. PMID:24146086

  20. Ways of giving benefits in marriage: norm use, relationship satisfaction, and attachment-related variability.

    PubMed

    Clark, Margaret S; Lemay, Edward P; Graham, Steven M; Pataki, Sherri P; Finkel, Eli J

    2010-07-01

    Couples reported on bases for giving support and on relationship satisfaction just prior to and approximately 2 years into marriage. Overall, a need-based, noncontingent (communal) norm was seen as ideal and was followed, and greater use of this norm was linked to higher relationship satisfaction. An exchange norm was seen as not ideal and was followed significantly less frequently than was a communal norm; by 2 years into marriage, greater use of an exchange norm was linked with lower satisfaction. Insecure attachment predicted greater adherence to an exchange norm. Idealization of and adherence to a communal norm dropped slightly across time. As idealization of a communal norm and own use and partner use of a communal norm decreased, people high in avoidance increased their use of an exchange norm, whereas people low in avoidance decreased their use of an exchange norm. Anxious individuals evidenced tighter links between norm use and marital satisfaction relative to nonanxious individuals. Overall, a picture of people valuing a communal norm and striving toward adherence to a communal norm emerged, with secure individuals doing so with more success and equanimity across time than insecure individuals.

  1. Investigating Shared Norms in Multicultural Teams: Exploring How Team Member Scripts and Cognitive Adjustment Strategies Impact the Norm Formation Process

    ERIC Educational Resources Information Center

    McGurrin, Daniel Paul

    2015-01-01

    The purpose of this study was to understand how shared norms are developed in the early phase of multicultural team (MCT) formation. The development of shared norms is recognized as critical to MCTs' contributions to organizations, and they are a result of the cognitive adjustment of the team members in recognition of their differences (Brandl…

  2. Bodies obliged and unbound: differentiated response tendencies for injunctive and descriptive social norms.

    PubMed

    Jacobson, Ryan P; Mortensen, Chad R; Cialdini, Robert B

    2011-03-01

    The authors suggest that injunctive and descriptive social norms engage different psychological response tendencies when made selectively salient. On the basis of suggestions derived from the focus theory of normative conduct and from consideration of the norms' functions in social life, the authors hypothesized that the 2 norms would be cognitively associated with different goals, would lead individuals to focus on different aspects of self, and would stimulate different levels of conflict over conformity decisions. Additionally, a unique role for effortful self-regulation was hypothesized for each type of norm-used as a means to resist conformity to descriptive norms but as a means to facilitate conformity for injunctive norms. Four experiments supported these hypotheses. Experiment 1 demonstrated differences in the norms' associations to the goals of making accurate/efficient decisions and gaining/maintaining social approval. Experiment 2 provided evidence that injunctive norms lead to a more interpersonally oriented form of self-awareness and to a greater feeling of conflict about conformity decisions than descriptive norms. In the final 2 experiments, conducted in the lab (Experiment 3) and in a naturalistic environment (Experiment 4), self-regulatory depletion decreased conformity to an injunctive norm (Experiments 3 and 4) and increased conformity to a descriptive norm (Experiment 4)-even though the norms advocated identical behaviors. By illustrating differentiated response tendencies for each type of social norm, this research provides new and converging support for the focus theory of normative conduct. (c) 2011 APA, all rights reserved

  3. Social Norms about a Health Issue in Work Group Networks

    PubMed Central

    Frank, Lauren B.

    2015-01-01

    The purpose of this study is to advance theorizing about how small groups understand health issues through the use of social network analysis. To achieve this goal, an adapted cognitive social structure examines group social norms around a specific health issue, H1N1 flu prevention. As predicted, individual’s attitudes, self-efficacy, and perceived social norms were each positively associated with behavioral intentions for at least one of the H1N1 health behaviors studied. Moreover, collective norms of the whole group were also associated with behavioral intentions, even after controlling for how individual group members perceive those norms. For members of work groups in which pairs were perceived to agree in their support for H1N1 vaccination, the effect of individually perceived group norms on behavioral intentions was stronger than for groups with less agreement. PMID:26389934

  4. Predictors of photo naming: Dutch norms for 327 photos.

    PubMed

    Shao, Zeshu; Stiegert, Julia

    2016-06-01

    In the present study, we report naming latencies and norms for 327 photos of objects in Dutch. We provide norms for eight psycholinguistic variables: age of acquisition, familiarity, imageability, image agreement, objective and subjective visual complexity, word frequency, word length in syllables and letters, and name agreement. Furthermore, multiple regression analyses revealed that the significant predictors of photo-naming latencies were name agreement, word frequency, imageability, and image agreement. The naming latencies, norms, and stimuli are provided as supplemental materials.

  5. Utility of Inferential Norming with Smaller Sample Sizes

    ERIC Educational Resources Information Center

    Zhu, Jianjun; Chen, Hsin-Yi

    2011-01-01

    We examined the utility of inferential norming using small samples drawn from the larger "Wechsler Intelligence Scales for Children-Fourth Edition" (WISC-IV) standardization data set. The quality of the norms was estimated with multiple indexes such as polynomial curve fit, percentage of cases receiving the same score, average absolute…

  6. An integrated moral obligation model for landowner conservation norms

    USGS Publications Warehouse

    Pradhananga, Amit K.; Davenport, Mae A.; Fulton, David C.; Maruyama, Geoffrey M.; Current, Dean

    2017-01-01

    This study applies an integrated moral obligation model to examine the role of environmental and cultural values, and beliefs in the activation of landowner conservation norms. Data for this study were collected through a self-administered survey of riparian landowners in two Minnesota watersheds: Sand Creek and Vermillion River watersheds. Study findings suggest that collectivistic and biospheric–altruistic values form the bases for the activation of personal norms. Further, beliefs about local responsibility and ability to act influence personal norms to protect water resources. Findings suggest that landowners’ personal norms of water conservation are more likely to be activated by conservation strategies that appeal to biospheric–altruistic and collectivistic values, emphasize adverse consequences of water pollution, highlight water resource protection as a local responsibility, and provide the resources needed to protect water resources.

  7. How embarrassing! The behavioral and neural correlates of processing social norm violations

    PubMed Central

    van Steenbergen, Henk; Kreuk, Tanja; van der Wee, Nic J. A.; Westenberg, P. Michiel

    2017-01-01

    Social norms are important for human social interactions, and violations of these norms are evaluated partly on the intention of the actor. Here, we describe the revised Social Norm Processing Task (SNPT-R), a paradigm enabling the study of behavioral and neural responses to intended and unintended social norm violations among both adults and adolescents. We investigated how participants (adolescents and adults, n = 87) rate intentional and unintentional social norm violations with respect to inappropriateness and embarrassment, and we examined the brain activation patterns underlying the processing of these transgressions in an independent sample of 21 adults using functional Magnetic Resonance Imaging (fMRI). We hypothesized to find activation within the medial prefrontal cortex, temporo-parietal cortex and orbitofrontal cortex in response to both intentional and unintentional social norm violations, with more pronounced activation for the intentional social norm violations in these regions and in the amygdala. Participants’ ratings confirmed the hypothesis that the three types of stories are evaluated differently with respect to intentionality: intentional social norm violations were rated as the most inappropriate and most embarrassing. Furthermore, fMRI results showed that reading stories on intentional and unintentional social norm violations evoked activation within the frontal pole, the paracingulate gyrus and the superior frontal gyrus. In addition, processing unintentional social norm violations was associated with activation in, among others, the orbitofrontal cortex, middle frontal gyrus and superior parietal lobule, while reading intentional social norm violations was related to activation in the left amygdala. These regions have been previously implicated in thinking about one’s self, thinking about others and moral reasoning. Together, these findings indicate that the SNPT-R could serve as a useful paradigm for examining social norm processing

  8. A Modified CIPW Norm Calculation for Lunar Mare Basalts

    NASA Technical Reports Server (NTRS)

    Milliken, R. E.; Basu, A.

    2000-01-01

    CIPW norms of lunar mare basalts are anomalously low in pyroxene. A modified norm calculation allowing higher Ca, Ti, Al, Cr, and Mn in di' and hy' obtains closer matches between normative and modal mineralogy.

  9. ℓ1-norm and entanglement in screening out braiding from Yang-Baxter equation associated with Z3 parafermion

    NASA Astrophysics Data System (ADS)

    Yu, Li-Wei; Ge, Mo-Lin

    2017-03-01

    The relationships between quantum entangled states and braid matrices have been well studied in recent years. However, most of the results are based on qubits. In this paper, we investigate the applications of 2-qutrit entanglement in the braiding associated with Z3 parafermion. The 2-qutrit entangled state | Ψ (θ) >, generated by the action of the localized unitary solution R ˘ (θ) of YBE on 2-qutrit natural basis, achieves its maximal ℓ1-norm and maximal von Neumann entropy simultaneously at θ = π / 3. Meanwhile, at θ = π / 3, the solutions of YBE reduces braid matrices, which implies the role of ℓ1-norm and entropy plays in determining real physical quantities. On the other hand, we give a new realization of 4-anyon topological basis by qutrit entangled states, then the 9 × 9 localized braid representation in 4-qutrit tensor product space (C3) ⊗ 4 is reduced to Jones representation of braiding in the 4-anyon topological basis. Hence, we conclude that the entangled states are powerful tools in analysing the characteristics of braiding and R ˘ -matrix.

  10. Potential environmental and regulatory implications of naturally occurring radioactive materials (NORM).

    PubMed

    Paschoa, A S

    1998-03-01

    The immense volume of naturally occurring radioactive materials (NORM) wastes produced annually by extracting industries throughout the world deserves to come to the attention of international and national environmental protection agencies and regulatory bodies. Although a great deal of work has been done in the fields of radiation protection and remedial actions concerning uranium and other mines, the need to dispose of diffuse NORM wastes will have environmental and regulatory implications that thus far are not fully appreciated. NORM wastes constitute, by and large, unwanted byproducts of industrial activities as diverse as thorium and uranium milling, niobium, tin and gold mining extraction, water treatment, and the production of oil, gas, phosphate fertilizer, coal fire and aluminum. The volumes of NORM wastes produced annually could reach levels so high that the existing low level radioactive waste (LLRW) facilities would be readily occupied by NORM if controlled disposal procedures were not adopted. On the other hand, NORM cannot just be ignored as being below radiological concern (BRC) or lower than exempt concentration levels (ECLs), because sometimes NORM concentrations reach levels as high as 1 x 10(3) kBq/kg for 226Ra, and not much less for 228Ra. Unfortunately, thus far there is not enough information available concerning NORM wastes in key industries, though the international scientific community has been concerned, for a long time now, with technologically enhanced natural radiation exposures (TENRE). This article is written with the intention of examining, to the extent possible, the potential environmental and regulatory implications of NORM wastes being produced in selected industries.

  11. A case study on the formation and sharing process of science classroom norms

    NASA Astrophysics Data System (ADS)

    Chang, Jina; Song, Jinwoong

    2016-03-01

    The teaching and learning of science in school are influenced by various factors, including both individual factors, such as member beliefs, and social factors, such as the power structure of the class. To understand this complex context affected by various factors in schools, we investigated the formation and sharing process of science classroom norms in connection with these factors. By examining the developmental process of science classroom norms, we identified how the norms were realized, shared, and internalized among the members. We collected data through classroom observations and interviews focusing on two elementary science classrooms in Korea. From these data, factors influencing norm formation were extracted and developed as stories about norm establishment. The results indicate that every science classroom norm was established, shared, and internalized differently according to the values ingrained in the norms, the agent of norm formation, and the members' understanding about the norm itself. The desirable norms originating from values in science education, such as having an inquiring mind, were not established spontaneously by students, but were instead established through well-organized norm networks to encourage concrete practice. Educational implications were discussed in terms of the practice of school science inquiry, cultural studies, and value-oriented education.

  12. Injunctive Social Norms Primacy over Descriptive Social Norms in Retirement Savings Decisions

    ERIC Educational Resources Information Center

    Croy, Gerry; Gerrans, Paul; Speelman, Craig

    2010-01-01

    Consistent with the global trend to shift responsibility for retirement income provision from the public purse to individuals has been encouragement to save more and to manage investment strategy. Analyzing data from 2,300 respondents to a randomly distributed questionnaire, this article focuses on the motivational importance of social norms. The…

  13. Do social norms affect intended food choice?

    PubMed

    Croker, H; Whitaker, K L; Cooke, L; Wardle, J

    2009-01-01

    To evaluate the effect of social norms on intended fruit and vegetable intake. A two-stage design to i) compare the perceived importance of normative influences vs cost and health on dietary choices, and ii) test the prediction that providing information on social norms will increase intended fruit and vegetable consumption in an experimental study. Home-based interviews (N=1083; 46% men, 54% women) were carried out as part of the Office for National Statistics Omnibus Survey in November 2008. The public's perception of the importance of social norms was lower (M=2.1) than the perceived importance of cost (M=2.7) or health (M=3.4) (all p's<0.001) on a scale from 1 (not at all important) to 4 (very important). In contrast, results from the experimental study showed that intentions to eat fruit and vegetables were positively influenced by normative information (p=0.011) in men but not by health or cost information; none of the interventions affected women's intentions. People have little awareness of the influence of social norms but normative information can have a demonstrable impact on dietary intentions. Health promotion might profit from emphasising how many people are attempting to adopt healthy lifestyles rather than how many have poor diets.

  14. Using the RxNorm Web Services API for Quality Assurance Purposes

    PubMed Central

    Peters, Lee; Bodenreider, Olivier

    2008-01-01

    Auditing large, rapidly evolving terminological systems is still a challenge. In the case of RxNorm, a standardized nomenclature for clinical drugs, we argue that quality assurance processes can benefit from the recently released application programming interface (API) provided by RxNav. We demonstrate the usefulness of the API by performing a systematic comparison of alternative paths in the RxNorm graph, over several thousands of drug entities. This study revealed potential errors in RxNorm, currently under review. The results also prompted us to modify the implementation of RxNav to navigate the RxNorm graph more accurately. The RxNorm web services API used in this experiment is robust and fast. PMID:18999038

  15. Punish and voice: punishment enhances cooperation when combined with norm-signalling.

    PubMed

    Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-Mir, Jordi; Solaz, Hector; Villatoro, Daniel

    2013-01-01

    Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices.

  16. Correlation of spacecraft thermal mathematical models to reference data

    NASA Astrophysics Data System (ADS)

    Torralbo, Ignacio; Perez-Grande, Isabel; Sanz-Andres, Angel; Piqueras, Javier

    2018-03-01

    Model-to-test correlation is a frequent problem in spacecraft-thermal control design. The idea is to determine the values of the parameters of the thermal mathematical model (TMM) that allows reaching a good fit between the TMM results and test data, in order to reduce the uncertainty of the mathematical model. Quite often, this task is performed manually, mainly because a good engineering knowledge and experience is needed to reach a successful compromise, but the use of a mathematical tool could facilitate this work. The correlation process can be considered as the minimization of the error of the model results with regard to the reference data. In this paper, a simple method is presented suitable to solve the TMM-to-test correlation problem, using Jacobian matrix formulation and Moore-Penrose pseudo-inverse, generalized to include several load cases. Aside, in simple cases, this method also allows for analytical solutions to be obtained, which helps to analyze some problems that appear when the Jacobian matrix is singular. To show the implementation of the method, two problems have been considered, one more academic, and the other one the TMM of an electronic box of PHI instrument of ESA Solar Orbiter mission, to be flown in 2019. The use of singular value decomposition of the Jacobian matrix to analyze and reduce these models is also shown. The error in parameter space is used to assess the quality of the correlation results in both models.

  17. Descriptive drinking norms in Native American and non-Hispanic White college students.

    PubMed

    Hagler, Kylee J; Pearson, Matthew R; Venner, Kamilla L; Greenfield, Brenna L

    2017-09-01

    College students tend to overestimate how much their peers drink, which is associated with higher personal alcohol use. However, research has not yet examined if this phenomenon holds true among Native American (NA) college students. This study examined associations between descriptive norms and alcohol use/consequences in a sample of NA and non-Hispanic White (NHW) college students. NA (n=147, 78.6% female) and NHW (n=246, 67.8% female) undergraduates completed an online survey. NAs NHWs showed similar descriptive norms such that the "typical college student," "typical NA student," and "typical NHW student" were perceived to drink more than "best friends." "Best friends" descriptive norms (i.e., estimations of how many drinks per week were consumed by participants' best friends) were the most robust predictors of alcohol use/consequences. Effect size estimates of the associations between drinking norms and participants' alcohol use were consistently positive and ranged from r=0.25 to r=0.51 across the four reference groups. Negative binomial hurdle models revealed that all descriptive norms tended to predict drinking, and "best friends" drinking norms predicted alcohol consequences. Apart from one interaction effect, likely due to familywise error rate, these associations were not qualified by interactions with racial/ethnic group. We found similar patterns between NAs and NHWs both in the pattern of descriptive norms across reference groups and in the strength of associations between descriptive norms and alcohol use/consequences. Although these results suggest that descriptive norms operate similarly among NAs as other college students, additional research is needed to identify whether other norms (e.g., injunctive norms) operate similarly across NA and NHW students. Copyright © 2017. Published by Elsevier Ltd.

  18. Radiological criteria for unrestricted use of sites containing norm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bernhardt, D.E.; Rogers, V.C.; Nielson, K.K.

    1996-06-01

    Natural occurring radioactive materia (NORM) is redistributed in the environment as a result of many mineral recovery and processing industries. There are not federal regulations specifying criteria for NORM contaminated sites; however, several states have promulgated regulations. The regulations promulgated by the states generally focus on NORM from oil and gas production, the primary focus of the assessments for this paper. The criteria for residual NORM in soil are generally (1) 0.18 Bq g{sup -1} in the surface 15 cm of soil and 0.6 Bq g{sup -1} at depth or (2) 1.1 Bq g{sup -1}, with a limitation on themore » radon flux. The primary radiation dose pathways for unrestricted use of land are external gamma exposure and exposure related to indoor radon. Radiation doses vary by over an order of magnitude based on different ratios of {sup 226}Ra to {sup 228}Ra concentrations, biological uptake parameters related to NORM, and the different radon emanation factors for oil field scale and sludge. A {sup 226}Ra criterion of 1.1 Bq g{sup -1} results in a dose of about 2 mSv y{sup -1} from external gamma and about 3 mSv y{sup -1} from radon for a general crawl-space type residence home scenario. The chemical and physical characteristics of the NORM and site-specific factors are important considerations in the assessments. The radon dose would be about 3 times higher for NORM in sludge, vs. the assumption of pipe scale. The structural characteristics of residences (e.g., slab-on-grade, crawl-space, or trailer) also have a significant impact on the potential doses to residences.« less

  19. easyCBM Norms. 2014 Edition. Technical Report #1409

    ERIC Educational Resources Information Center

    Saven, Jessica L.; Tindal, Gerald; Irvin, P. Shawn; Farley, Dan; Alonzo, Julie

    2014-01-01

    Previous norms for the easyCBM assessment system were computed using scores from all students who took each measure for every grade and benchmark season (fall, winter, and spring). During the 2013-­14 school year, new national norms were developed to more accurately (proportionately) represent reading and mathematics performance by two variables:…

  20. Norms governing urban African American adolescents’ sexual and substance-using behavior

    PubMed Central

    Dolcini, M. Margaret; Catania, Joseph A.; Harper, Gary W.; Watson, Susan E.; Ellen, Jonathan M.; Towner, Senna L.

    2013-01-01

    Using a probability-based neighborhood sample of urban African American youth and a sample of their close friends (N = 202), we conducted a one-year longitudinal study to examine key questions regarding sexual and drug using norms. The results provide validation of social norms governing sexual behavior, condom use, and substance use among friendship groups. These norms had strong to moderate homogeneity; and both normative strength and homogeneity were relatively stable over a one-year period independent of changes in group membership. The data further suggest that sex and substance using norms may operate as a normative set. Similar to studies of adults, we identified three distinct “norm-based” social strata in our sample. Together, our findings suggest that the norms investigated are valid targets for health promotion efforts, and such efforts may benefit from tailoring programs to the normative sets that make up the different social strata in a given adolescent community. PMID:23072891

  1. Young Children See a Single Action and Infer a Social Norm.

    PubMed

    Schmidt, Marco F H; Butler, Lucas P; Heinz, Julia; Tomasello, Michael

    2016-10-01

    Human social life depends heavily on social norms that prescribe and proscribe specific actions. Typically, young children learn social norms from adult instruction. In the work reported here, we showed that this is not the whole story: Three-year-old children are promiscuous normativists. In other words, they spontaneously inferred the presence of social norms even when an adult had done nothing to indicate such a norm in either language or behavior. And children of this age even went so far as to enforce these self-inferred norms when third parties "broke" them. These results suggest that children do not just passively acquire social norms from adult behavior and instruction; rather, they have a natural and proactive tendency to go from "is" to "ought." That is, children go from observed actions to prescribed actions and do not perceive them simply as guidelines for their own behavior but rather as objective normative rules applying to everyone equally.

  2. Social Norm, Family Communication, and HBV Screening among Asian Americans.

    PubMed

    Juon, Hee-Soon; Rimal, Rajiv N; Klassen, Ann; Lee, Sunmin

    2017-12-01

    Individuals' behaviors are influenced by those of others in their social environment (i.e., descriptive norms), as well as by how individuals perceive they should behave in that environment (e.g., injunctive norms). Although social norms are thought to play an important role in hepatitis B virus (HBV) screening, limited theoretical or empirical guidance exists on how the underlying process works. In addition, norms are social phenomena that are spread through family discussion about the importance of getting HBV screening. Using the theory of normative social behavior (TNSB), this study examined the roles of injunctive norms (IN), descriptive norms (DN), and family discussion in HBV screening behavior among Asian Americans. Data from a survey of Asian Americans in the Baltimore Washington metropolitan area (N = 877) were used to test underlying theoretical propositions. DN and family discussion emerged as key factors in HBV screening behavior among all Asian Americans. IN were associated with HBV screening among Chinese and Korean Americans, but not for Vietnamese Americans. Family discussion moderated the influence of DN on behavior among Chinese and Vietnamese Americans. However, the main effect of DN on screening behavior was not modified by IN (no interactions between DN and IN). The results indicate that family discussion and social norms are integral in enabling Asian Americans to undergo HBV screening and warrant sensitivity in the design and implementation of a liver cancer prevention program in this high-risk group of Asian Americans.

  3. Management of Naturally Occurring Radioactive Materials (NORM) in Canada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baweja, Anar S.; Tracy, Bliss L.

    2008-08-07

    In Canada, nuclear and radiological regulatory responsibilities are shared between the provinces/territories and the federal government. The Canadian Nuclear Safety Commission (CNSC) regulates nuclear fuel cycle materials and man-made radionuclides under the Nuclear Safety and Control Act (2000). The provinces and territories regulate NORM arising from industrial activities, not involving the nuclear fuel cycle materials. Present guideline--Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials (NORM)--was published in 2000 in order to bring uniformity to the management of NORM-related procedures to provide adequate radiation protection for workers and the general public. The basic premise of these guidelines is thatmore » the NORM-related activities should not be posing any greater hazard than those activities regulated under the Nuclear Safety and Control Act; these concepts are described in this paper.« less

  4. Relationship among values, beliefs, norms and ecological behaviour.

    PubMed

    González López, Antonio; Amérigo Cuervo-Arango, María

    2008-11-01

    The present study focuses mainly on the relationship between psychological constructs and ecological behaviour. Empirical analysis links personal values, ecological beliefs, consequences of environmental conditions, denial of ecological obligation, environmental control, personal norms and environment protection behaviour. Survey data from a path analysis of a Spanish sample of 403 individuals were used, showing that ecological beliefs, personal norms and eco-altruistic values have become the main psychological explanatory variables of environment protective behaviour. Ecological beliefs, when measured by the New Ecological Paradigm Scale, affected ecological behaviour decisively. Environmental and altruistic values were shown to be related to moral obligation, and a basic variable to understand behaviour. Personal norm mediated the effects of values and environmental control on ecological behaviour.

  5. Jimmy's baby doll and Jenny's truck: young children's reasoning about gender norms.

    PubMed

    Conry-Murray, Clare; Turiel, Elliot

    2012-01-01

    To assess the flexibility of reasoning about gender, children ages 4, 6, and 8 years (N = 72) were interviewed about gender norms when different domains were highlighted. The majority of participants at all ages judged a reversal of gender norms in a different cultural context to be acceptable. They also judged gender norms as a matter of personal choice and they negatively evaluated a rule enforcing gender norms in schools. Older children were more likely to show flexibility than younger children. Justifications obtained from 6- and 8-year-olds showed that they considered adherence to gender norms a matter of personal choice and they viewed the rule enforcing gender norms as unfair. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

  6. Understanding multiple levels of norms about teen pregnancy and their relationships to teens' sexual behaviors.

    PubMed

    Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

    2014-06-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys' perceived norms, while peer network norms predict girls' perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens' likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys' contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.

  7. Understanding multiple levels of norms about teen pregnancy and their relationships to teens’ sexual behaviors

    PubMed Central

    Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

    2014-01-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys’ perceived norms, while peer network norms predict girls’ perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens’ likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys’ contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors. PMID:25104920

  8. Marketing Norm Perception Among Medical Representatives in Indian Pharmaceutical Industry

    PubMed Central

    Nagashekhara, Molugulu; Agil, Syed Omar Syed; Ramasamy, Ravindran

    2012-01-01

    Study of marketing norm perception among medical representatives is an under-portrayed component that deserves further perusal in the pharmaceutical industry. The purpose of this study is to find out the perception of marketing norms among medical representatives. The research design is quantitative and cross sectional study with medical representatives as unit of analysis. Data is collected from medical representatives (n=300) using a simple random and cluster sampling using a structured questionnaire. Results indicate that there is no difference in the perception of marketing norms among male and female medical representatives. But there is a difference in opinion among domestic and multinational company’s medical representatives. Educational back ground of medical representatives also shows the difference in opinion among medical representatives. Degree holders and multinational company medical representatives have high perception of marketing norms compare to their counterparts. The researchers strongly believe that mandatory training on marketing norms is beneficial in decision making process during the dilemmas in the sales field. PMID:24826035

  9. Fruit and Vegetable Attitudes, Norms, and Intake in Low-Income Youth.

    PubMed

    Di Noia, Jennifer; Cullen, Karen Weber

    2015-12-01

    Fruit and vegetable (FV) attitudes and norms have been shown to influence intake in youth; yet research with low-income youth and studies supplementing self-report with objective measures of intake are lacking. Cross-sectional survey data on self-rated FV intake, FV attitudes, and FV norms were collected in a sample of 116 youth attending a residential summer camp serving low-income families. FV intake also was estimated by direct observation. Differences between self-rated and observed FV intake, perceived and observed peer intake, and perceived and peer-reported attitudes toward eating FVs were assessed with paired samples t tests. The role of FV attitudes, descriptive norms (perceived peer FV intake), injunctive norms (perceived peer attitudes toward eating FVs), and actual norms (observed peer FV intake and peer-reported FV attitudes) in predicting FV intake also was examined with multiple regression analysis. Youth misperceived their own and their peers' FV intake (i.e., overestimated intake of fruit and underestimated intake of vegetables) and believed that peers held less favorable attitudes toward eating FVs than was the case. The models predicting self-rated intake were significant, accounting for 34% of the variance in fruit intake and 28% of the variance in vegetable intake. Attitudes and descriptive norms were positively associated with FV intake, and observed peer fruit intake was negatively associated with fruit intake. Findings suggest that in low-income youth, FV attitudes, descriptive norms, and normative peer behavior predict perceived but not actual intake. Youth may benefit from intervention to promote favorable FV attitudes and norms. A focus on descriptive norms holds promise for improving self-rated intake in this population. © 2015 Society for Public Health Education.

  10. The Quest for Quality--Towards Joint European Quality Norms.

    ERIC Educational Resources Information Center

    Bartholomeus, Yvonne, Ed.; And Others

    This book contains the following papers about considerations in developing joint European quality norms for vocational guidance: "Joint Quality Norms in Guidance"; "Careers Guidance in the Information Society" (Frans Meijers); "The Changing Nature of Guidance" (J. Chamberlain); "Quality with Policy: Beyond…

  11. Perceived eating norms and children's eating behaviour: An informational social influence account.

    PubMed

    Sharps, Maxine; Robinson, Eric

    2017-06-01

    There is initial evidence that beliefs about the eating behaviour of others (perceived eating norms) can influence children's vegetable consumption, but little research has examined the mechanisms explaining this effect. In two studies we aimed to replicate the effect that perceived eating norms have on children's vegetable consumption, and to explore mechanisms which may underlie the influence of perceived eating norms on children's vegetable consumption. Study 1 investigated whether children follow perceived eating norms due to a desire to maintain personal feelings of social acceptance. Study 2 investigated whether perceived eating norms influence eating behaviour because eating norms provide information which can remove uncertainty about how to behave. Across both studies children were exposed to vegetable consumption information of other children and their vegetable consumption was examined. In both studies children were influenced by perceived eating norms, eating more when led to believe others had eaten a large amount compared to when led to believe others had eaten no vegetables. In Study 1, children were influenced by a perceived eating norm regardless of whether they felt sure or unsure that other children accepted them. In Study 2, children were most influenced by a perceived eating norm if they were eating in a novel context in which it may have been uncertain how to behave, as opposed to an eating context that children had already encountered. Perceived eating norms may influence children's eating behaviour by removing uncertainty about how to behave, otherwise known as informational social influence. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Punish and Voice: Punishment Enhances Cooperation when Combined with Norm-Signalling

    PubMed Central

    Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-Mir, Jordi; Solaz, Hector; Villatoro, Daniel

    2013-01-01

    Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices. PMID:23776441

  13. True gender ratios and stereotype rating norms

    PubMed Central

    Garnham, Alan; Doehren, Sam; Gygax, Pascal

    2015-01-01

    We present a study comparing, in English, perceived distributions of men and women in 422 named occupations with actual real world distributions. The first set of data was obtained from previous a large-scale norming study, whereas the second set was mostly drawn from UK governmental sources. In total, real world ratios for 290 occupations were obtained for our perceive vs. real world comparison, of which 205 were deemed to be unproblematic. The means for the two sources were similar and the correlation between them was high, suggesting that people are generally accurate at judging real gender ratios, though there were some notable exceptions. Beside this correlation, some interesting patterns emerged from the two sources, suggesting some response strategies when people complete norming studies. We discuss these patterns in terms of the way real world data might complement norming studies in determining gender stereotypicality. PMID:26257681

  14. Social norm enforcement in ethnically diverse communities

    PubMed Central

    Zhang, Nan

    2018-01-01

    Recent waves of immigration to Western nations have fueled a debate over the consequences of ethnic diversity for social cohesion. One prominent argument in this debate holds that diversity is detrimental to trust and cooperation because individuals in heterogeneous communities face difficulties in enforcing social norms across ethnic lines. We examine this proposition in a field experiment involving real-life interactions among residents of multiethnic German neighborhoods. We find significant ethnic asymmetries in the pattern of norm enforcement: Members of the majority “native” German population are more active in sanctioning norm violations, while ethnic minorities are more likely to find themselves the target of sanctions. We interpret these results in light of prevailing status inequalities between ethnic minorities and the native majority. We further calculate that, as a result of ethnic discrimination, social control is likely to rise in communities with moderate minority population shares. PMID:29483253

  15. Enabling phenotypic big data with PheNorm.

    PubMed

    Yu, Sheng; Ma, Yumeng; Gronsbell, Jessica; Cai, Tianrun; Ananthakrishnan, Ashwin N; Gainer, Vivian S; Churchill, Susanne E; Szolovits, Peter; Murphy, Shawn N; Kohane, Isaac S; Liao, Katherine P; Cai, Tianxi

    2018-01-01

    Electronic health record (EHR)-based phenotyping infers whether a patient has a disease based on the information in his or her EHR. A human-annotated training set with gold-standard disease status labels is usually required to build an algorithm for phenotyping based on a set of predictive features. The time intensiveness of annotation and feature curation severely limits the ability to achieve high-throughput phenotyping. While previous studies have successfully automated feature curation, annotation remains a major bottleneck. In this paper, we present PheNorm, a phenotyping algorithm that does not require expert-labeled samples for training. The most predictive features, such as the number of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes or mentions of the target phenotype, are normalized to resemble a normal mixture distribution with high area under the receiver operating curve (AUC) for prediction. The transformed features are then denoised and combined into a score for accurate disease classification. We validated the accuracy of PheNorm with 4 phenotypes: coronary artery disease, rheumatoid arthritis, Crohn's disease, and ulcerative colitis. The AUCs of the PheNorm score reached 0.90, 0.94, 0.95, and 0.94 for the 4 phenotypes, respectively, which were comparable to the accuracy of supervised algorithms trained with sample sizes of 100-300, with no statistically significant difference. The accuracy of the PheNorm algorithms is on par with algorithms trained with annotated samples. PheNorm fully automates the generation of accurate phenotyping algorithms and demonstrates the capacity for EHR-driven annotations to scale to the next level - phenotypic big data. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  16. McCarthyism's Rhetorical Norms.

    ERIC Educational Resources Information Center

    Townsend, Rebecca M.

    Rhetorical norms of early McCarthyist discourse reveal a reliance upon images of chaos and the body. Through such metaphors, rhetors crafted a model of discussion that feminized "democracy" and "tolerance" to support anti-Communist measures and de-legitimize their opponents. Political variety was coded as deviant to national…

  17. Social norms and family planning decisions in South Sudan.

    PubMed

    Kane, Sumit; Kok, Maryse; Rial, Matilda; Matere, Anthony; Dieleman, Marjolein; Broerse, Jacqueline Ew

    2016-11-22

    With a maternal mortality ratio of 789 per 100,000 live births, and a contraceptive prevalence rate of 4.7%, South Sudan has one of the worst reproductive health situations in the world. Understanding the social norms around sexuality and reproduction, across different ethnic groups, is key to developing and implementing locally appropriate public health responses. A qualitative study was conducted in the state of Western Bahr el Ghazal (WBeG) in South Sudan to explore the social norms shaping decisions about family planning among the Fertit community. Data were collected through five focus group discussions and 44 semi-structured interviews conducted with purposefully selected community members and health personnel. Among the Fertit community, the social norm which expects people to have as many children as possible remains well established. It is, however, under competitive pressure from the existing norm which makes spacing of pregnancies socially desirable. Young Fertit women are increasingly, either covertly or overtly, making family planning decisions themselves; with resistance from some menfolk, but also support from others. The social norm of having as many children as possible is also under competitive pressure from the emerging norm that equates taking good care of one's children with providing them with a good education. The return of peace and stability in South Sudan, and people's aspirations for freedom and a better life, is creating opportunities for men and women to challenge and subvert existing social norms, including but not limited to those affecting reproductive health, for the better. The sexual and reproductive health programmes in WBeG should work with and leverage existing and emerging social norms on spacing in their health promotion activities. Campaigns should focus on promoting a family ideal in which children become the object of parental investment, rather than labour to till the land - instead of focusing directly or solely on

  18. "Who Doesn't?"--The Impact of Descriptive Norms on Corruption.

    PubMed

    Köbis, Nils C; van Prooijen, Jan-Willem; Righetti, Francesca; Van Lange, Paul A M

    2015-01-01

    Corruption poses one of the major societal challenges of our time. Considerable advances have been made in understanding corruption on a macro level, yet the psychological antecedents of corrupt behavior remain largely unknown. In order to explain why some people engage in corruption while others do not, we explored the impact of descriptive social norms on corrupt behavior by using a novel behavioral measure of corruption. We conducted three studies to test whether perceived descriptive norms of corruption (i.e. the belief about the prevalence of corruption in a specific context) influence corrupt behavior. The results indicated that descriptive norms highly correlate with corrupt behavior--both when measured before (Study 1) or after (Study 2) the behavioral measure of corruption. Finally, we adopted an experimental design to investigate the causal effect of descriptive norms on corruption (Study 3). Corrupt behavior in the corruption game significantly drops when participants receive short anti-corruption descriptive norm primes prior to the game. These findings indicate that perceived descriptive norms can impact corrupt behavior and, possibly, could offer an explanation for inter-personal and inter-cultural variation in corrupt behavior in the real world. We discuss implications of these findings and draw avenues for future research.

  19. Civility norms, safety climate, and safety outcomes: a preliminary investigation.

    PubMed

    McGonagle, Alyssa K; Walsh, Benjamin M; Kath, Lisa M; Morrow, Stephanie L

    2014-10-01

    Working environments that are both civil and safe are good for business and employee well-being. Civility has been empirically linked to such important outcomes as organizational performance and individuals' positive work-related attitudes, yet research relating civility to safety is lacking. In this study, we link perceptions of civility norms to perceptions of safety climate and safety outcomes. Drawing on social exchange theory, we proposed and tested a model in 2 samples wherein civility norms indirectly relate to safety outcomes through associations with various safety climate facets. Our results supported direct relationships between civility and management safety climate and coworker safety climate. Additionally, indirect effects of civility norms on unsafe behaviors and injuries were observed. Indirect effects of civility norms on unsafe behaviors were observed through coworker safety climate and work-safety tension. Indirect effects of civility norms on injuries were observed through management safety climate and work-safety tension for full-time employees, although these effects did not hold for part-time employees. This study provides initial evidence that researchers and practitioners may want to look beyond safety climate to civility norms to more comprehensively understand the origins of unsafe behaviors and injuries and to develop appropriate preventive interventions. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  20. Descriptive peer norms, self-control and dietary behaviour in young adults.

    PubMed

    Robinson, Eric; Otten, Roy; Hermans, Roel C J

    2016-01-01

    There is evidence that perceived peer eating norms can influence dietary behaviour. This cross-sectional study examined whether certain personality traits increase the likelihood that personal eating habits are similar to perceived peer eating habits. We assessed frequency of consumption of sugar-sweetened soda (SSS) and sweet pastries (SP), as well as perceived peer descriptive eating norms for SSS and SP in a group of 1056 young adults. We examined whether individual differences in the need for social acceptance and self-control moderated whether participants were likely to display similar dietary habits to their peers. Perceived peer eating norms for SSS and SP predicted frequency of consumption; believing that one's peers frequently consumed SSS and SP was associated with increased personal consumption for both. Individuals with low self-control, as opposed to high self-control, were more likely to adhere to peer norms for SP, but not for SSS. Trait social acceptance needs did not significantly moderate similarity between peer norms and personal consumption for either SSS or SP. The extent to which young adults adhere to descriptive peer dietary norms may depend upon self-control, whereby individuals with low self-control are less able to inhibit social influence of descriptive peer norms on dietary behaviour.

  1. Designing feedback to mitigate teen distracted driving: A social norms approach.

    PubMed

    Merrikhpour, Maryam; Donmez, Birsen

    2017-07-01

    The purpose of this research is to investigate teens' perceived social norms and whether providing normative information can reduce distracted driving behaviors among them. Parents are among the most important social referents for teens; they have significant influences on teens' driving behaviors, including distracted driving which significantly contributes to teens' crash risks. Social norms interventions have been successfully applied in various domains including driving; however, this approach is yet to be explored for mitigating driver distraction among teens. Forty teens completed a driving simulator experiment while performing a self-paced visual-manual secondary task in four between-subject conditions: a) social norms feedback that provided a report at the end of each drive on teens' distracted driving behavior, comparing their distraction engagement to their parent's, b) post-drive feedback that provided just the report on teens' distracted driving behavior without information on their parents, c) real-time feedback in the form of auditory warnings based on eyes of road-time, and d) no feedback as control. Questionnaires were administered to collect data on these teens' and their parents' self-reported engagement in driver distractions and the associated social norms. Social norms and real-time feedback conditions resulted in significantly smaller average off-road glance duration, rate of long (>2s) off-road glances, and standard deviation of lane position compared to no feedback. Further, social norms feedback decreased brake response time and percentage of time not looking at the road compared to no feedback. No major effect was observed for post-drive feedback. Questionnaire results suggest that teens appeared to overestimate parental norms, but no effect of feedback was found on their perceptions. Feedback systems that leverage social norms can help mitigate driver distraction among teens. Overall, both social norms and real-time feedback induced

  2. The hitchhiker's guide to altruism: gene-culture coevolution, and the internalization of norms.

    PubMed

    Gintis, Herbert

    2003-02-21

    An internal norm is a pattern of behavior enforced in part by internal sanctions, such as shame, guilt and loss of self-esteem, as opposed to purely external sanctions, such as material rewards and punishment. The ability to internalize norms is widespread among humans, although in some so-called "sociopaths", this capacity is diminished or lacking. Suppose there is one genetic locus that controls the capacity to internalize norms. This model shows that if an internal norm is fitness enhancing, then for plausible patterns of socialization, the allele for internalization of norms is evolutionarily stable. This framework can be used to model Herbert Simon's (1990) explanation of altruism, showing that altruistic norms can "hitchhike" on the general tendency of internal norms to be personally fitness-enhancing. A multi-level selection, gene-culture coevolution argument then explains why individually fitness-reducing internal norms are likely to be prosocial as opposed to socially harmful.

  3. Facial Anthropometric Norms among Kosovo - Albanian Adults.

    PubMed

    Staka, Gloria; Asllani-Hoxha, Flurije; Bimbashi, Venera

    2017-09-01

    The development of an anthropometric craniofacial database is a necessary multidisciplinary proposal. The aim of this study was to establish facial anthropometric norms and to investigate into sexual dimorphism in facial variables among Kosovo Albanian adults. The sample included 204 students of Dental School, Faculty of Medicine, University of Pristina. Using direct anthropometry, a series of 8 standard facial measurements was taken on each subject with digital caliper with an accuracy of 0.01 mm (Boss, Hamburg-Germany). The normative data and percentile rankings were calculated. Gender differences in facial variables were analyzed using t- test for independent samples (p<0.05). The index of sexual dimorphism (ISD) and percentage of sexual dimorphism were calculated for each facial measurement. ormative data for all facial anthropometric measurements in males were higher than in females. Male average norms compared with the female average norms differed significantly from each other (p>0.05).The highest index of sexual dimorphism (ISD) was found for the lower facial height 1.120, for which the highest percentage of sexual dimorphism, 12.01%., was also found. The lowest ISD was found for intercanthal width, 1.022, accompanied with the lowest percentage of sexual dimorphism, 2.23%. The obtained results have established the facial anthropometric norms among Kosovo Albanian adults. Sexual dimorphism has been confirmed for each facial measurement.

  4. Descriptive Drinking Norms: For Whom Does Reference Group Matter?*

    PubMed Central

    Larimer, Mary E.; Neighbors, Clayton; LaBrie, Joseph W.; Atkins, David C.; Lewis, Melissa A.; Lee, Christine M.; Kilmer, Jason R.; Kaysen, Debra L.; Pedersen, Eric r.; Montoya, Heidi; Hodge, Kimberley; Desai, Sruti; Hummer, Justin F.; Walter, Theresa

    2011-01-01

    Objective: Perceived descriptive drinking norms often differ from actual norms and are positively related to personal consumption. However, it is not clear how normative perceptions vary with specificity of the reference group. Are drinking norms more accurate and more closely related to drinking behavior as reference group specificity increases? Do these relationships vary as a function of participant demographics? The present study examined the relationship between perceived descriptive norms and drinking behavior by ethnicity (Asian or White), sex, and fraternity/sorority status. Method: Participants were 2,699 (58% female) White (75%) or Asian (25%) undergraduates from two universities who reported their own alcohol use and perceived descriptive norms for eight reference groups: "typical student"; same sex, ethnicity, or fraternity/sorority status; and all combinations of these three factors. Results: Participants generally reported the highest perceived norms for the most distal reference group (typical student), with perceptions becoming more accurate as individuals' similarity to the reference group increased. Despite increased accuracy, participants perceived that all reference groups drank more than was actually the case. Across specific subgroups (fraternity/sorority members and men) different patterns emerged. Fraternity/sorority members reliably reported higher estimates of drinking for reference groups that included fraternity/ sorority status, and, to a lesser extent, men reported higher estimates for reference groups that included men. Conclusions: The results suggest that interventions targeting normative misperceptions may need to provide feedback based on participant demography or group membership. Although reference group-specific feedback may be important for some subgroups, typical student feedback provides the largest normative discrepancy for the majority of students. PMID:21906510

  5. QSAR models for describing the toxicological effects of ILs against Staphylococcus aureus based on norm indexes.

    PubMed

    He, Wensi; Yan, Fangyou; Jia, Qingzhu; Xia, Shuqian; Wang, Qiang

    2018-03-01

    The hazardous potential of ionic liquids (ILs) is becoming an issue of great concern due to their important role in many industrial fields as green agents. The mathematical model for the toxicological effects of ILs is useful for the risk assessment and design of environmentally benign ILs. The objective of this work is to develop QSAR models to describe the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of ILs against Staphylococcus aureus (S. aureus). A total of 169 and 101 ILs with MICs and MBCs, respectively, are used to obtain multiple linear regression models based on matrix norm indexes. The norm indexes used in this work are proposed by our research group and they are first applied to estimate the antibacterial toxicity of these ILs against S. aureus. These two models precisely and reliably calculated the IL toxicities with a square of correlation coefficient (R 2 ) of 0.919 and a standard error of estimate (SE) of 0.341 (in log unit of mM) for pMIC, and an R 2 of 0.913 and SE of 0.282 for pMBC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Psycholinguistic norms for 320 fixed expressions (idioms and proverbs) in French.

    PubMed

    Bonin, Patrick; Méot, Alain; Boucheix, Jean-Michel; Bugaiska, Aurélia

    2018-05-01

    We provide psycholinguistic norms for a new set of 160 French idiomatic expressions and 160 proverbs: knowledge, predictability, literality, compositionality, subjective and objective frequency, familiarity, age of acquisition (AoA) and length. Different analyses (reliability, descriptive statistics and correlations) performed on the norms are reported and discussed. The norms can be downloaded as Supplemental Material .

  7. Gender Norms and Retaliatory Violence against Spouses and Acquaintances

    ERIC Educational Resources Information Center

    Feld, Scott L.; Felson, Richard B.

    2008-01-01

    This article examines an experiment embedded within a nationally representative survey of adult Americans to investigate gender norms regarding retaliatory violence between spouses and acquaintances. Contrary to claims that societal norms permit violence within marriage, respondents disapproved of retaliatory violence against spouses more than…

  8. Cultural differences in perceived social norms and social anxiety.

    PubMed

    Heinrichs, Nina; Rapee, Ronald M; Alden, Lynn A; Bögels, Susan; Hofmann, Stefan G; Oh, Kyung Ja; Sakano, Yuji

    2006-08-01

    Cultural considerations in social anxiety are a rarely investigated topic although it seems likely that differences between countries in social norms may relate to the extent of social anxiety. The present study investigated individuals' personal and perceived cultural norms and their relation to social anxiety and fear of blushing. A total of 909 participants from eight countries completed vignettes describing social situations and evaluated the social acceptability of the behavior of the main actor both from their own, personal perspective as well as from a cultural viewpoint. Personal and cultural norms showed somewhat different patterns in comparison between types of countries (individualistic/collectivistic). According to reported cultural norms, collectivistic countries were more accepting toward socially reticent and withdrawn behaviors than was the case in individualistic countries. In contrast, there was no difference between individualistic and collectivistic countries on individuals' personal perspectives regarding socially withdrawn behavior. Collectivistic countries also reported greater levels of social anxiety and more fear of blushing than individualistic countries. Significant positive relations occurred between the extent to which attention-avoiding behaviors are accepted in a culture and the level of social anxiety or fear of blushing symptoms. These results provide initial evidence that social anxiety may be related to different cultural norms across countries.

  9. The Centre for Speech, Language and the Brain (CSLB) concept property norms.

    PubMed

    Devereux, Barry J; Tyler, Lorraine K; Geertzen, Jeroen; Randall, Billi

    2014-12-01

    Theories of the representation and processing of concepts have been greatly enhanced by models based on information available in semantic property norms. This information relates both to the identity of the features produced in the norms and to their statistical properties. In this article, we introduce a new and large set of property norms that are designed to be a more flexible tool to meet the demands of many different disciplines interested in conceptual knowledge representation, from cognitive psychology to computational linguistics. As well as providing all features listed by 2 or more participants, we also show the considerable linguistic variation that underlies each normalized feature label and the number of participants who generated each variant. Our norms are highly comparable with the largest extant set (McRae, Cree, Seidenberg, & McNorgan, 2005) in terms of the number and distribution of features. In addition, we show how the norms give rise to a coherent category structure. We provide these norms in the hope that the greater detail available in the Centre for Speech, Language and the Brain norms should further promote the development of models of conceptual knowledge. The norms can be downloaded at www.csl.psychol.cam.ac.uk/propertynorms.

  10. Adolescents' physical activities and peer norms: the mediating role of self-efficacy.

    PubMed

    Lu, Frank J H; Lin, Ju-Han; Hsu, Ya-Wen; Chou, Chien-Chih; Wang, Erica T W; Yeh, Li-Chin

    2014-04-01

    The purpose of the present study was to examine the relations among adolescents' self-efficacy and social norms, and physical activity and whether self-efficacy mediated the relationship between social norms and physical activity. 400 junior high school students (202 boys, 198 girls, 2 not identified; M age = 15.3yr., SD = 0.6) completed a demographic questionnaire, the International Physical Activity Questionnaire (IPAQ), the Perceived Self-Efficacy in Physical Activity Scale, and the Physical Activity Social Norms Scale. Regression analyses indicated that both self-efficacy and social norms predicted physical activity. Self-efficacy fully mediated the relationship between peer norms and physical activity for boys but partially mediated the relationship for girls. An application of the results may be to foster self-efficacy and peer norms as a motivational strategy for supporting increased physical activity.

  11. Brain Stimulation Studies of Social Norm Compliance: Implications for Personality Disorders?

    PubMed

    Ruff, Christian C

    2018-01-01

    Several personality disorders involve pathological behaviors that violate social norms, commonly held expectations about what ought to be done in specific situations. These symptoms usually emerge early in development, are persistent and hard to treat, and are often ego-syntonic. Here I present some recent brain stimulation studies suggesting that pathological changes in different aspects of norm-compliant behavior reflect dysfunctions of brain circuits involving distinct prefrontal brain areas. One set of studies shows that transcranial direct current stimulation of the right lateral prefrontal cortex changes the behavioral sensitivity to social incentives for norm-compliant behavior. Crucially, social norm compliance in response to such incentives could even be increased during excitatory stimulation, demonstrating that the affected neural process is a biological prerequisite for appropriate reaction to social signals that trigger norm compliance. In another set of studies, we show that stimulation of a different (more dorsal) part of the right prefrontal cortex enhances honesty in a realistic setting where participants had the opportunity to cheat for real monetary gains. Interestingly, these stimulation-induced increases in both socially cued or purely voluntary norm compliance were not linked to changes in other aspects of decision- making (such as risk or impatience), and they did not reflect changes in beliefs about what is appropriate behavior. These results suggest that disorders of distinct brain circuits may causally underlie egosyntotic changes in norm-compliant behavior. This raises the tantalizing possibility that pathologies of norm-compliant behavior may be ameliorated by interventions targeting the function of these brain circuits. © 2018 S. Karger AG, Basel.

  12. On-Line Identification of Simulation Examples for Forgetting Methods to Track Time Varying Parameters Using the Alternative Covariance Matrix in Matlab

    NASA Astrophysics Data System (ADS)

    Vachálek, Ján

    2011-12-01

    The paper compares the abilities of forgetting methods to track time varying parameters of two different simulated models with different types of excitation. The observed parameters in the simulations are the integral sum of the Euclidean norm, deviation of the parameter estimates from their true values and a selected band prediction error count. As supplementary information, we observe the eigenvalues of the covariance matrix. In the paper we used a modified method of Regularized Exponential Forgetting with Alternative Covariance Matrix (REFACM) along with Directional Forgetting (DF) and three standard regularized methods.

  13. ADHD Rating Scale-IV: Checklists, Norms, and Clinical Interpretation

    ERIC Educational Resources Information Center

    Pappas, Danielle

    2006-01-01

    This article reviews the "ADHD Rating Scale-IV: Checklist, norms, and clinical interpretation," is a norm-referenced checklist that measures the symptoms of attention deficit/hyperactivity disorder (ADHD) according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric…

  14. A towel less: social norms enhance pro-environmental behavior in hotels.

    PubMed

    Reese, Gerhard; Loew, Kristina; Steffgen, Georges

    2014-01-01

    Previous research has shown that normative appeals to engage in environmentally friendly behavior were most effective when they were accompanied by a provincial norm (e.g., when norms matched individuals' immediate situational circumstances). Analyzing hotel guests' towel-use during their stay, the current study tests whether messages employing provincial norms were more effective in reducing towel-use than standard environmental messages. In line with previous findings, guests of two hotels used significantly fewer towels when provincial normative appeals--rather than standard environmental messages--were communicated. These findings corroborate to the body of research demonstrating the power of social norms on environmental behavior.

  15. Cephalometric norms for the Chinese: a compilation of existing data.

    PubMed

    Moate, S J; Darendeliler, M A

    2002-03-01

    The intention of this paper is to compile Chinese cephalometric norms for a more objective orthodontic diagnosis of Chinese patients so that their orthodontic treatment may be better planned. Studies on cephalometric norms of Chinese and subjects of Chinese descent were reviewed. Some important studies were available only in the Chinese journals and they were especially procured and translated for this purpose. A normal range of anteroposterior apical base differences, concomitant nterincisal inclinations and locations, were derived from different Chinese groups and were tabulated. The differences between Chinese and Caucasian norms are discussed. A distinctive craniofacial and dental pattern of the people of Chinese origin was found and is reflected in the cephalometric measurements. Compared with Caucasian norms, Chinese norms have skeletal, dental and soft-tissue variations. The Chinese have a shorter cranial base and a larger ANB. The Chinese dentition demonstrates greater bimaxillary-alveolar protrusion, with a decreased interincisal angle. The Chinese soft-tissue profile shows a less prominent nose, with a less obtuse nasolabial angle, and more protrusive lips.

  16. Kinematic equations for control of the redundant eight-degree-of-freedom advanced research manipulator 2

    NASA Technical Reports Server (NTRS)

    Williams, Robert L., II

    1992-01-01

    The forward position and velocity kinematics for the redundant eight-degree-of-freedom Advanced Research Manipulator 2 (ARM2) are presented. Inverse position and velocity kinematic solutions are also presented. The approach in this paper is to specify two of the unknowns and solve for the remaining six unknowns. Two unknowns can be specified with two restrictions. First, the elbow joint angle and rate cannot be specified because they are known from the end-effector position and velocity. Second, one unknown must be specified from the four-jointed wrist, and the second from joints that translate the wrist, elbow joint excluded. There are eight solutions to the inverse position problem. The inverse velocity solution is unique, assuming the Jacobian matrix is not singular. A discussion of singularities is based on specifying two joint rates and analyzing the reduced Jacobian matrix. When this matrix is singular, the generalized inverse may be used as an alternate solution. Computer simulations were developed to verify the equations. Examples demonstrate agreement between forward and inverse solutions.

  17. Low-rank matrix decomposition and spatio-temporal sparse recovery for STAP radar

    DOE PAGES

    Sen, Satyabrata

    2015-08-04

    We develop space-time adaptive processing (STAP) methods by leveraging the advantages of sparse signal processing techniques in order to detect a slowly-moving target. We observe that the inherent sparse characteristics of a STAP problem can be formulated as the low-rankness of clutter covariance matrix when compared to the total adaptive degrees-of-freedom, and also as the sparse interference spectrum on the spatio-temporal domain. By exploiting these sparse properties, we propose two approaches for estimating the interference covariance matrix. In the first approach, we consider a constrained matrix rank minimization problem (RMP) to decompose the sample covariance matrix into a low-rank positivemore » semidefinite and a diagonal matrix. The solution of RMP is obtained by applying the trace minimization technique and the singular value decomposition with matrix shrinkage operator. Our second approach deals with the atomic norm minimization problem to recover the clutter response-vector that has a sparse support on the spatio-temporal plane. We use convex relaxation based standard sparse-recovery techniques to find the solutions. With extensive numerical examples, we demonstrate the performances of proposed STAP approaches with respect to both the ideal and practical scenarios, involving Doppler-ambiguous clutter ridges, spatial and temporal decorrelation effects. As a result, the low-rank matrix decomposition based solution requires secondary measurements as many as twice the clutter rank to attain a near-ideal STAP performance; whereas the spatio-temporal sparsity based approach needs a considerably small number of secondary data.« less

  18. Diagnosis and prevention of norm at Eugene Island 341-A

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shuler, P.J.; Baudoin, D.A.; Weintritt, D.J.

    1995-12-01

    We conducted a field study at Eugene Island 341-A to develop guidelines for the cost-effective prevention of NORM (Naturally Occurring Radioactive Materials). The specific objectives of this study are to: determine the root cause of the NORM problem at this facility, using a wide variety of diagnostic techniques. consider available engineering options to prevent NORM from forming. determine the most cost-effective engineering solution. An overall objective is to Generalize the results and diagnostic techniques developed for Eugene Island 341-A to other production facilities, especially in the Gulf of Mexico. This study shows that the NORM problem at Eugene Island 34more » 1-A stems from mixing incompatible produced waters at the surface. Wells completed in Sand Block A have a water with relatively high barium concentration, those in Sand Block B and C are high in sulfate, When these waters mix (starting in the production headers), barium sulfate forms. Radium that is present in the produced brines co-precipitates with the barium, thus creating a radioactive barium sulfate scale deposit (NORM). The barium sulfate (and hence NORM) can be prevented by improving the current scale inhibition program. Keys to an effective program are the continual, reliable injection of an appropriate scale inhibitor at an effective dosage, ahead of the point where scaling conditions begin.« less

  19. Professional Development of PMRI Teachers for Introducing Social Norms

    ERIC Educational Resources Information Center

    Putri, Ratu Ilma Indra; Dolk, Maarten; Zulkardi

    2015-01-01

    This paper reports implementation results of designing a workshop for mathematics teachers in introducing classroom social norms. The participants are eight mathematics teachers in primary and junior secondary level. Teachers learned and did some activities about social norms during the workshop. First, they watched an example of learning videos…

  20. The Subjectivity of the Translator and Socio-Cultural Norms

    ERIC Educational Resources Information Center

    Pei, Denghua

    2010-01-01

    This thesis attempts to probe into the dialectical relationship between the subjectivity of the translator and socio-cultural norms. The socio-cultural norms inevitably regulate the translator's translating activity, as acceptability of the translated text is the primary concern of most translators. However, this does not mean that the…

  1. Reconstruction algorithms based on l1-norm and l2-norm for two imaging models of fluorescence molecular tomography: a comparative study.

    PubMed

    Yi, Huangjian; Chen, Duofang; Li, Wei; Zhu, Shouping; Wang, Xiaorui; Liang, Jimin; Tian, Jie

    2013-05-01

    Fluorescence molecular tomography (FMT) is an important imaging technique of optical imaging. The major challenge of the reconstruction method for FMT is the ill-posed and underdetermined nature of the inverse problem. In past years, various regularization methods have been employed for fluorescence target reconstruction. A comparative study between the reconstruction algorithms based on l1-norm and l2-norm for two imaging models of FMT is presented. The first imaging model is adopted by most researchers, where the fluorescent target is of small size to mimic small tissue with fluorescent substance, as demonstrated by the early detection of a tumor. The second model is the reconstruction of distribution of the fluorescent substance in organs, which is essential to drug pharmacokinetics. Apart from numerical experiments, in vivo experiments were conducted on a dual-modality FMT/micro-computed tomography imaging system. The experimental results indicated that l1-norm regularization is more suitable for reconstructing the small fluorescent target, while l2-norm regularization performs better for the reconstruction of the distribution of fluorescent substance.

  2. Boosting safety behaviour: Descriptive norms encourage child booster seat usage amongst low involvement parents.

    PubMed

    Jeffrey, Jennifer; Whelan, Jodie; Pirouz, Dante M; Snowdon, Anne W

    2016-07-01

    Campaigns advocating behavioural changes often employ social norms as a motivating technique, favouring injunctive norms (what is typically approved or disapproved) over descriptive norms (what is typically done). Here, we investigate an upside to including descriptive norms in health and safety appeals. Because descriptive norms are easy to process and understand, they should provide a heuristic to guide behaviour in those individuals who lack the interest or motivation to reflect on the advocated behaviour more deeply. When those descriptive norms are positive - suggesting that what is done is consistent with what ought to be done - including them in campaigns should be particularly beneficial at influencing this low-involvement segment. We test this proposition via research examining booster seat use amongst parents with children of booster seat age, and find that incorporating positive descriptive norms into a related campaign is particularly impactful for parents who report low involvement in the topic of booster seat safety. Descriptive norms are easy to state and easy to understand, and our research suggests that these norms resonate with low involvement individuals. As a result, we recommend incorporating descriptive norms when possible into health and safety campaigns. Copyright © 2016. Published by Elsevier Ltd.

  3. Analysis of Hypersonic Vehicle Wakes

    DTIC Science & Technology

    2015-09-17

    factor used with viscous Jacobian matrix of left eigenvectors for A R specific gas constant Re Reynolds number Recell cell Reynolds number......focus was shifted to characterizing other wake phenomena. The aerothermal phenomena of interest in the wake include: gas properties, chemical species

  4. Attitude ambivalence, social norms, and behavioral intentions: Developing effective antitobacco persuasive communications.

    PubMed

    Hohman, Zachary P; Crano, William D; Niedbala, Elizabeth M

    2016-03-01

    This study assessed the moderating effects of attitude ambivalence on the relationship between social norms, attitudes, and behavioral intentions to use tobacco. It was predicted that people would use social norms to reduce attitude ambivalence, and that reduced ambivalence would lead to changes in attitudes and behavioral intentions. To test this hypothesis, participants (N = 152) were exposed to persuasive communications designed to influence attitude ambivalence and perceived social norms regarding tobacco use. Analysis indicated that providing a social norm antagonistic to tobacco use significantly reduced ambivalence among participants reading the ambivalence message (p < .001). Examining changes in tobacco attitudes from pre- to postpersuasive communications demonstrated a significant decrease in tobacco attitudes only for participants reading the ambivalence message who were provided with the antitobacco use norm (p < .001). Ambivalent message participants also expressed significantly lower intentions to use tobacco when provided with social norms indicating antitobacco sentiments (p < .02), and this significant decrease in intentions was associated with changes in attitudes toward tobacco. These results point to the important role of social norms in mediating the effects of attitude ambivalence on subsequent behavior in preventative programs targeting tobacco use. (c) 2016 APA, all rights reserved).

  5. Attitude Ambivalence, Social Norms, and Behavioral Intentions: Developing Effective Antitobacco Persuasive Communications

    PubMed Central

    Hohman, Zachary P.; Crano, William D.; Niedbala, Elizabeth M.

    2018-01-01

    This study assessed the moderating effects of attitude ambivalence on the relationship between social norms, attitudes, and behavioral intentions to use tobacco. It was predicted that people would use social norms to reduce attitude ambivalence, and that reduced ambivalence would lead to changes in attitudes and behavioral intentions. To test this hypothesis, participants (N =152) were exposed to persuasive communications designed to influence attitude ambivalence and perceived social norms regarding tobacco use. Analysis indicated that providing a social norm antagonistic to tobacco use significantly reduced ambivalence among participants reading the ambivalence message (p <.001). Examining changes in tobacco attitudes from pre- to postpersuasive communications demonstrated a significant decrease in tobacco attitudes only for participants reading the ambivalence message who were provided with the antitobacco use norm (p <.001). Ambivalent message participants also expressed significantly lower intentions to use tobacco when provided with social norms indicating antitobacco sentiments (p <.02), and this significant decrease in intentions was associated with changes in attitudes toward tobacco. These results point to the important role of social norms in mediating the effects of attitude ambivalence on subsequent behavior in preventative programs targeting tobacco use. PMID:26460476

  6. [French norms of imagery for pictures, for concrete and abstract words].

    PubMed

    Robin, Frédérique

    2006-09-01

    This paper deals with French norms for mental image versus picture agreement for 138 pictures and the imagery value for 138 concrete words and 69 abstract words. The pictures were selected from Snodgrass et Vanderwart's norms (1980). The concrete words correspond to the dominant naming response to the pictorial stimuli. The abstract words were taken from verbal associative norms published by Ferrand (2001). The norms were established according to two variables: 1) mental image vs. picture agreement, and 2) imagery value of words. Three other variables were controlled: 1) picture naming agreement; 2) familiarity of objects referred to in the pictures and the concrete words, and 3) subjective verbal frequency of words. The originality of this work is to provide French imagery norms for the three kinds of stimuli usually compared in research on dual coding. Moreover, these studies focus on figurative and verbal stimuli variations in visual imagery processes.

  7. A comparative study of minimum norm inverse methods for MEG imaging

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Leahy, R.M.; Mosher, J.C.; Phillips, J.W.

    1996-07-01

    The majority of MEG imaging techniques currently in use fall into the general class of (weighted) minimum norm methods. The minimization of a norm is used as the basis for choosing one from a generally infinite set of solutions that provide an equally good fit to the data. This ambiguity in the solution arises from the inherent non- uniqueness of the continuous inverse problem and is compounded by the imbalance between the relatively small number of measurements and the large number of source voxels. Here we present a unified view of the minimum norm methods and describe how we canmore » use Tikhonov regularization to avoid instabilities in the solutions due to noise. We then compare the performance of regularized versions of three well known linear minimum norm methods with the non-linear iteratively reweighted minimum norm method and a Bayesian approach.« less

  8. The empirical study of norms is just what we are missing

    PubMed Central

    Achourioti, Theodora; Fugard, Andrew J. B.; Stenning, Keith

    2014-01-01

    This paper argues that the goals people have when reasoning determine their own norms of reasoning. A radical descriptivism which avoids norms never worked for any science; nor can it work for the psychology of reasoning. Norms as we understand them are illustrated with examples from categorical syllogistic reasoning and the “new paradigm” of subjective probabilities. We argue that many formal systems are required for psychology: classical logic, non-monotonic logics, probability logics, relevance logic, and others. One of the hardest challenges is working out what goals reasoners have and choosing and tailoring the appropriate logics to model the norms those goals imply. PMID:25368590

  9. Norms about Nonmarital Pregnancy and Willingness to Provide Resources to Unwed Parents

    ERIC Educational Resources Information Center

    Mollborn, Stefanie

    2009-01-01

    Contested social norms underlie public concern about adults' and teenagers' nonmarital pregnancy. The original, vignette-based National Pregnancy Norms Survey (N = 812) measures these norms and related sanctions. Descriptive analyses report embarrassment at the prospect of a nonmarital pregnancy by age and gender of hypothetical prospective…

  10. Longitudinal Relationship Between Drinking with Peers, Descriptive Norms, and Adolescent Alcohol Use

    PubMed Central

    Brooks-Russell, Ashley; Simons-Morton, Bruce; Haynie, Denise; Farhat, Tilda; Wang, Jing

    2014-01-01

    Descriptive norms are consistently found to predict adolescent alcohol use but less is known about the factors that predict descriptive norms. The objective of this study is to test if drinking with peers predicts later alcohol consumption and if this relationship is mediated by a change in the descriptive norms of peer alcohol use. Data are from a nationally representative cohort of high school students surveyed in the 10th and 11th grade (N=2,162). Structural equation modeling was used to test a mediation model of the relationship between drinking with peers (T1) on later alcohol use (T2) and mediation of the relationship by descriptive norms (T2). Descriptive norms significantly mediated the relationship between drinking with peers and alcohol use for both males and females with a somewhat larger effect for males compared to females. These results support a continued focus on the development and evaluation of interventions to alter descriptive norms of alcohol use. PMID:23564529

  11. Conditions for the Emergence of Shared Norms in Populations with Incompatible Preferences

    PubMed Central

    Helbing, Dirk; Yu, Wenjian; Opp, Karl-Dieter; Rauhut, Heiko

    2014-01-01

    Understanding norms is a key challenge in sociology. Nevertheless, there is a lack of dynamical models explaining how one of several possible behaviors is established as a norm and under what conditions. Analysing an agent-based model, we identify interesting parameter dependencies that imply when two behaviors will coexist or when a shared norm will emerge in a heterogeneous society, where different populations have incompatible preferences. Our model highlights the importance of randomness, spatial interactions, non-linear dynamics, and self-organization. It can also explain the emergence of unpopular norms that do not maximize the collective benefit. Furthermore, we compare behavior-based with preference-based punishment and find interesting results concerning hypocritical punishment. Strikingly, pressuring others to perform the same public behavior as oneself is more effective in promoting norms than pressuring others to meet one’s own private preference. Finally, we show that adaptive group pressure exerted by randomly occuring, local majorities may create norms under conditions where different behaviors would normally coexist. PMID:25166137

  12. Longitudinal relationship between drinking with peers, descriptive norms, and adolescent alcohol use.

    PubMed

    Brooks-Russell, Ashley; Simons-Morton, Bruce; Haynie, Denise; Farhat, Tilda; Wang, Jing

    2014-08-01

    Descriptive norms are consistently found to predict adolescent alcohol use but less is known about the factors that predict descriptive norms. The objective of this study is to test if drinking with peers predicts later alcohol consumption and if this relationship is mediated by a change in the descriptive norms of peer alcohol use. Data are from a nationally representative cohort of high school students surveyed in the 10th and 11th grade (N = 2,162). Structural equation modeling was used to test a mediation model of the relationship between drinking with peers (T1) on later alcohol use (T2) and mediation of the relationship by descriptive norms (T2). Descriptive norms significantly mediated the relationship between drinking with peers and alcohol use for both males and females with a somewhat larger effect for males compared to females. These results support a continued focus on the development and evaluation of interventions to alter descriptive norms of alcohol use.

  13. From Blame to Punishment: Disrupting Prefrontal Cortex Activity Reveals Norm Enforcement Mechanisms.

    PubMed

    Buckholtz, Joshua W; Martin, Justin W; Treadway, Michael T; Jan, Katherine; Zald, David H; Jones, Owen; Marois, René

    2015-09-23

    The social welfare provided by cooperation depends on the enforcement of social norms. Determining blameworthiness and assigning a deserved punishment are two cognitive cornerstones of norm enforcement. Although prior work has implicated the dorsolateral prefrontal cortex (DLPFC) in norm-based judgments, the relative contribution of this region to blameworthiness and punishment decisions remains poorly understood. Here, we used repetitive transcranial magnetic stimulation (rTMS) and fMRI to determine the specific role of DLPFC function in norm-enforcement behavior. DLPFC rTMS reduced punishment for wrongful acts without affecting blameworthiness ratings, and fMRI revealed punishment-selective DLPFC recruitment, suggesting that these two facets of norm-based decision making are neurobiologically dissociable. Finally, we show that DLPFC rTMS affects punishment decision making by altering the integration of information about culpability and harm. Together, these findings reveal a selective, causal role for DLPFC in norm enforcement: representational integration of the distinct information streams used to make punishment decisions. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Eating for Two? Protocol of an Exploratory Survey and Experimental Study on Social Norms and Norm-Based Messages Influencing European Pregnant and Non-pregnant Women's Eating Behavior.

    PubMed

    Bevelander, Kirsten E; Herte, Katharina; Kakoulakis, Catherine; Sanguino, Inés; Tebbe, Anna-Lena; Tünte, Markus R

    2018-01-01

    The social context is an important factor underlying unhealthy eating behavior and the development of inappropriate weight gain. Evidence is accumulating that powerful social influences can also be used as a tool to impact people's eating behavior in a positive manner. Social norm-based messages have potential to steer people in making healthier food choices. The research field on nutritional social norms is still emerging and more research is needed to gain insights into why some people adhere to social norms whereas others do not. There are indications stemming from empirical studies on social eating behavior that this may be due to ingratiation purposes and uncertainty reduction. That is, people match their eating behavior to that of the norm set by their eating companion(s) in order to blend in and be part of the group. In this project, we explore nutritional social norms among pregnant women. This population is particularly interesting because they are often subject to unsolicited advice and experience social pressure from their environment. In addition, their pregnancy affects their body composition, eating pattern, and psychosocial status. Pregnancy provides an important window of opportunity to impact health of pregnant women and their child. Nevertheless, the field of nutritional social norms among pregnant women is understudied and more knowledge is needed on whether pregnant women use guidelines from their social environment for their own eating behavior. In this project we aim to fill this research gap by means of an exploratory survey (Study 1) assessing information about social expectations, (mis)perceived social norms and the role of different reference groups such as other pregnant women, family, and friends. In addition, we conduct an online experiment (Study 2) testing to what extent pregnant women are susceptible to social norm-based messages compared to non-pregnant women. Moreover, possible moderators are explored which might impact women

  15. Norms and Varieties of English and TESOL Teacher Agency

    ERIC Educational Resources Information Center

    Hamid, M. Obaidul; Zhu, Lingyan; Baldauf, Richard B., Jr.

    2014-01-01

    The growing recognition of the plurality of English underlying the World Englishes (WE) paradigm has problematised the conventional second language acquisition (SLA) views of errors. If English use in emerging English-speaking contexts is to be judged by local norms, as argued by WE scholars, applying exocentric norms in these contexts can be…

  16. Norms of certain Jordan elementary operators

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoli; Ji, Guoxing

    2008-10-01

    Let be a complex Hilbert space and let denote the algebra of all bounded linear operators on . For , the Jordan elementary operator UA,B is defined by UA,B(X)=AXB+BXA, . In this short note, we discuss the norm of UA,B. We show that if and ||UA,B||=||A||||B||, then either AB* or B*A is 0. We give some examples of Jordan elementary operators UA,B such that ||UA,B||=||A||||B|| but AB*[not equal to]0 and B*A[not equal to]0, which answer negatively a question posed by M. Boumazgour in [M. Boumazgour, Norm inequalities for sums of two basic elementary operators, J. Math. Anal. Appl. 342 (2008) 386-393].

  17. Minority acculturation and peer rejection: Costs of acculturation misfit with peer-group norms.

    PubMed

    Celeste, Laura; Meeussen, Loes; Verschueren, Karine; Phalet, Karen

    2016-09-01

    How do minority adolescents' personal acculturation preferences and peer norms of acculturation affect their social inclusion in school? Turkish and Moroccan minority adolescents (N = 681) reported their preferences for heritage culture maintenance, mainstream culture adoption, and their experiences of peer rejection as a key indicator of adjustment problems. Additionally, we aggregated peer acculturation norms of maintenance and adoption within ethnically diverse classrooms (N = 230 in 50 Belgian schools), distinguishing between co-ethnic (Turkish or Moroccan classmates only, N = 681) and cross-ethnic norms (also including N = 1,930 other classmates). Cross-ethnic peer-group norms (of adoption and maintenance) and co-ethnic norms (of maintenance, marginally) predicted minority experiences of peer rejection (controlling for ethnic composition). Moreover, misfit of minorities' own acculturation preferences with both cross-ethnic and co-ethnic peer-group norms was harmful. When cross-ethnic norms stressed adoption, 'integrationist' minority youth - who combined culture adoption with maintenance - experienced most peer rejection. Yet, when co-ethnic peers stressed maintenance, 'assimilationist' minority youth experienced most rejection. In conclusion, acculturation misfit with peer-group norms is a risk factor for minority inclusion in ethnically diverse environments. © 2016 The British Psychological Society.

  18. Challenging dominant norms of masculinity for HIV prevention.

    PubMed

    MacPhail, Catherine

    2003-01-01

    Within South Africa there is a growing HIV epidemic, particularly among young heterosexual people. A recent report (NMF/HSRC, 2002) indicates that levels of HIV infection among young people aged 15-24 years are 9.3% although other studies in more specific locations have shown levels to be higher than this. One of the best means of developing successful and innovative HIV prevention programmes for young people is to enhance our understandings of youth sexuality and the manner in which dominant norms contribute to the spread of sexually transmitted diseases. Social norms of masculinity are particularly important in this regard, as the manner in which 'normal' men are defined such as through acquisition of multiple partners, power over women and negative attitudes towards condoms, are often in conflict with the true emotional vulnerabilities of young men. Given the strong influence of peer groups on young people and the belief that one of the solutions to behaviour change lies in peer renegotiation of dominant norms, there is the need to begin to investigate young men who challenge dominant norms of masculinity. It is in investigating their points of view that a platform for the deconstruction of stereotypical masculinities and the reconstruction of new norms can be formed. The paper begins to consider these counter normative ideas through highlighting the discussions of young South African men aged 13-25 years in focus groups and in-depth individual interviews conducted in Gauteng Province. It is apparent that among this group there are young men challenging normative views of masculinity in a manner that could be harnessed within HIV prevention initiatives.

  19. Reliance on God, prayer, and religion reduces influence of perceived norms on drinking.

    PubMed

    Neighbors, Clayton; Brown, Garrett A; Dibello, Angelo M; Rodriguez, Lindsey M; Foster, Dawn W

    2013-05-01

    Previous research has shown that perceived social norms are among the strongest predictors of drinking among young adults. Research has also consistently found religiousness to be protective against risk and negative health behaviors. The present research evaluates the extent to which reliance on God, prayer, and religion moderates the association between perceived social norms and drinking. Participants (n = 1,124 undergraduate students) completed a cross-sectional survey online, which included measures of perceived norms, religious values, and drinking. Perceived norms were assessed by asking participants their perceptions of typical student drinking. Drinking outcomes included drinks per week, drinking frequency, and typical quantity consumed. Regression analyses indicated that religiousness and perceived norms had significant unique associations in opposite directions for all three drinking outcomes. Significant interactions were evident between religiousness and perceived norms in predicting drinks per week, frequency, and typical quantity. In each case, the interactions indicated weaker associations between norms and drinking among those who assigned greater importance to religiousness. The extent of the relationship between perceived social norms and drinking was buffered by the degree to which students identified with religiousness. A growing body of literature has shown interventions including personalized feedback regarding social norms to be an effective strategy in reducing drinking among college students. The present research suggests that incorporating religious or spiritual values into student interventions may be a promising direction to pursue.

  20. College-Bound Teens’ Decisions about the Transition to Sex: Negotiating Competing Norms

    PubMed Central

    Mollborn, Stefanie

    2012-01-01

    The normative influence of parents, close friends, and other peers on teens’ sexual behavior has been well documented. Yet, we still know little about the processes through which these oftentimes competing norms impact teens’ own sexual norms and behaviors. Drawing on qualitative data from 47 interviews conducted with college-bound teens, we investigate the processes through which perceived parental, close friend, and other peer norms about sex influenced teens’ decisions about whether and when to have sex. Although virtually all teens perceived that most of their peers were having sex and that parents were almost universally against teen sex, some teens had sex and others did not. Our findings demonstrate that teens who remained virgins and those who were sexually active during high school often negotiated different sets of competing norms. Differences in understandings of age norms, in close friends’ sexual norms and behaviors, and in communication about sex with parents, close friends and other peers were related to different levels of sexual behavior for teens who otherwise shared many similarities in social location (e.g.. class, race, and educational status). While virgins reported an individualized process of deciding whether they were ready for sex, we find that their behavior fits within a traditional understanding of an age norm because of the emphasis on avoiding negative sanctions. Sexually experienced teens, on the other hand, explicitly reported abiding by a group age norm that prescribed sex as normal during high school. Finally, parents’ normative objections to teen sex – either moral or practical – and the ways they communicated with their teen about sex had important influence on teens’ own sexual norms and behaviors during high school. PMID:22439133

  1. Development of fast measurements of concentration of NORM U-238 by HPGe

    NASA Astrophysics Data System (ADS)

    Cha, Seokki; Kim, Siu; Kim, Geehyun

    2017-02-01

    Naturally Occureed Radioactive Material (NORM) generated from the origin of earth can be found all around us and even people who are not engaged in the work related to radiation have been exposed to unnecessary radiation. This NORM has a potential risk provided that is concentrated or transformed by artificial activities. Likewise, a development of fast measruement method of NORM is emerging to prevent the radiation exposure of the general public and person engaged in the work related to the type of business related thereto who uses the material in which NORM is concentrated or transfromed. Based on such a background, many of countries have tried to manage NORM and carried out regulatory legislation. To effienctly manage NORM, there is need for developing new measurement to quickly and accurately analyze the nuclide and concentration. In this study, development of the fast and reliable measurement was carried out. In addition to confirming the reliability of the fast measurement, we have obtained results that can suggest the possibility of developing another fast measurement. Therefore, as a follow-up, it is possible to develop another fast analytical measurement afterwards. The results of this study will be very useful for the regulatory system to manage NORM. In this study, a review of two indirect measurement methods of NORM U-238 that has used HPGe on the basis of the equilibrium theory of relationships of mother and daughter nuclide at decay-chain of NORM U-238 has been carried out. For comparative study(in order to know reliabily), direct measurement that makes use of alpha spectrometer with complicated pre-processing process was implemented.

  2. Regularization Parameter Selection for Nonlinear Iterative Image Restoration and MRI Reconstruction Using GCV and SURE-Based Methods

    PubMed Central

    Ramani, Sathish; Liu, Zhihao; Rosen, Jeffrey; Nielsen, Jon-Fredrik; Fessler, Jeffrey A.

    2012-01-01

    Regularized iterative reconstruction algorithms for imaging inverse problems require selection of appropriate regularization parameter values. We focus on the challenging problem of tuning regularization parameters for nonlinear algorithms for the case of additive (possibly complex) Gaussian noise. Generalized cross-validation (GCV) and (weighted) mean-squared error (MSE) approaches (based on Stein's Unbiased Risk Estimate— SURE) need the Jacobian matrix of the nonlinear reconstruction operator (representative of the iterative algorithm) with respect to the data. We derive the desired Jacobian matrix for two types of nonlinear iterative algorithms: a fast variant of the standard iterative reweighted least-squares method and the contemporary split-Bregman algorithm, both of which can accommodate a wide variety of analysis- and synthesis-type regularizers. The proposed approach iteratively computes two weighted SURE-type measures: Predicted-SURE and Projected-SURE (that require knowledge of noise variance σ2), and GCV (that does not need σ2) for these algorithms. We apply the methods to image restoration and to magnetic resonance image (MRI) reconstruction using total variation (TV) and an analysis-type ℓ1-regularization. We demonstrate through simulations and experiments with real data that minimizing Predicted-SURE and Projected-SURE consistently lead to near-MSE-optimal reconstructions. We also observed that minimizing GCV yields reconstruction results that are near-MSE-optimal for image restoration and slightly sub-optimal for MRI. Theoretical derivations in this work related to Jacobian matrix evaluations can be extended, in principle, to other types of regularizers and reconstruction algorithms. PMID:22531764

  3. Concurrent MR-NIR Imaging for Breast Cancer Diagnosis

    DTIC Science & Technology

    2008-06-01

    the extended Kalman filtering (EKF) framework. Note that both the fluorophore concentrations in different compartments, C(rj , k), and the system...r1 − r2)δ(k1 − k2)Z1. 10) Estimation of Pharmacokinetic-Rate Images by Extended Kalman Filtering: Our objective is to estimate the fluorophore...covariance update at time k. Hk is the recursive Kalman gain matrix at time k and I is the identity matrix. Jk−1 is the Jacobian matrix due to iterative

  4. From Abstract to Concrete Norms in Agent Institutions

    NASA Technical Reports Server (NTRS)

    Grossi, Davide; Dignum, Frank

    2004-01-01

    Norms specifying constraints over institutions are stated in such a form that allows them to regulate a wide range of situations over time without need for modification. To guarantee this stability, the formulation of norms need to abstract from a variety of concrete aspects, which are instead relevant for the actual operationalization of institutions. If agent institutions are to be built, which comply with a set of abstract requirements, how can those requirements be translated in more concrete constraints the impact of which can be described directly in the institution? In this work we make use of logical methods in order to provide a formal characterization of the translation rules that operate the connection between abstract and concrete norms. On the basis of this characterization, a comprehensive formalization of the notion of institution is also provided.

  5. The Ability of Narrative Communication to Address Health-related Social Norms

    PubMed Central

    Moran, Meghan Bridgid; Murphy, Sheila T.; Frank, Lauren; Baezconde-Garbanati, Lourdes

    2013-01-01

    Social norms are an important predictor of health behavior and have been targeted by a variety of health communication campaigns. However, these campaigns often encounter challenges related to the socially specific context in which norms exist: specifically, the extent to which the target population identifies with the reference group presented in the ad and the extent to which the target population believes the campaign's message. We argue that because of its capacity to effect identification among viewers, narrative communication is particularly appropriate for impacting social norms and, consequently, behavioral intention. This manuscript presents the results of a randomized trial testing the effectiveness of two films – one narrative, one non-narrative – in changing perceived social norms and behavioral intention regarding Pap testing to detect cervical cancer. Results of the study indicate that the narrative film was in fact more effective at producing positive changes in perceived norm and intention. PMID:24179677

  6. Television Content Viewing Patterns: Some Clues from Societal Norms.

    ERIC Educational Resources Information Center

    McDonald, Daniel G.; Glynn, Carroll J.

    Focusing on how television viewing fits into a general model of consumer consumption patterns, a study examined (1) the extent to which the viewing of certain television content can be considered a "norm" of society, (2) similarities and differences between the norms for adults and those for children, and (3) some of the antecedents of…

  7. Closing the contrast gap between testbed and model prediction with WFIRST-CGI shaped pupil coronagraph

    NASA Astrophysics Data System (ADS)

    Zhou, Hanying; Nemati, Bijan; Krist, John; Cady, Eric; Prada, Camilo M.; Kern, Brian; Poberezhskiy, Ilya

    2016-07-01

    JPL has recently passed an important milestone in its technology development for a proposed NASA WFIRST mission coronagraph: demonstration of better than 1x10-8 contrast over broad bandwidth (10%) on both shaped pupil coronagraph (SPC) and hybrid Lyot coronagraph (HLC) testbeds with the WFIRST obscuration pattern. Challenges remain, however, in the technology readiness for the proposed mission. One is the discrepancies between the achieved contrasts on the testbeds and their corresponding model predictions. A series of testbed diagnoses and modeling activities were planned and carried out on the SPC testbed in order to close the gap. A very useful tool we developed was a derived "measured" testbed wavefront control Jacobian matrix that could be compared with the model-predicted "control" version that was used to generate the high contrast dark hole region in the image plane. The difference between these two is an estimate of the error in the control Jacobian. When the control matrix, which includes both amplitude and phase, was modified to reproduce the error, the simulated performance closely matched the SPC testbed behavior in both contrast floor and contrast convergence speed. This is a step closer toward model validation for high contrast coronagraphs. Further Jacobian analysis and modeling provided clues to the possible sources for the mismatch: DM misregistration and testbed optical wavefront error (WFE) and the deformable mirror (DM) setting for correcting this WFE. These analyses suggested that a high contrast coronagraph has a tight tolerance in the accuracy of its control Jacobian. Modifications to both testbed control model as well as prediction model are being implemented, and future works are discussed.

  8. Validity of Other-Gender-Normed Scales on the Kuder Occupational Interest Survey.

    ERIC Educational Resources Information Center

    Zytowski, Donald G.; Laing, Joan

    1978-01-01

    Investigated the relationship between KOIS twin scales normed separately on males and females for occupations and college majors. Rankings on own- and other-gender-normed scales correlated highly. The scales were approximately equal in predictive validity. Rankings on other-gender-normed scales provided an accurate estimate of expected rankings on…

  9. The Effect of Descriptive Norms on Pregaming Frequency: Tests of Five Moderators.

    PubMed

    Merrill, Jennifer E; Kenney, Shannon R; Carey, Kate B

    2016-07-02

    Pregaming is highly prevalent on college campuses and associated with heightened levels of intoxication and risk of alcohol consequences. However, research examining the correlates of pregaming behavior is limited. Descriptive norms (i.e., perceptions about the prevalence or frequency of a behavior) are reliable and comparatively strong predictors of general drinking behavior, with recent evidence indicating that they are also associated with pregaming. We tested the hypothesis that higher descriptive norms for pregaming frequency would be associated with personal pregaming frequency. We also tested whether this effect would be stronger in the context of several theory-based moderators: female gender, higher injunctive norms (i.e., perceptions of others' attitudes toward a particular behavior), a more positive attitude toward pregaming, a stronger sense of identification with the drinking habits of other students, and stronger social comparison tendencies. College student drinkers (N = 198, 63% female) participated in an online survey assessing frequency of pregaming, descriptive norms, and hypothesized moderators. A multiple regression model revealed that higher descriptive norms, a more positive attitude toward pregaming, and stronger peer identification were significantly associated with greater pregaming frequency among drinkers. However, no moderators of the association between descriptive norms and pregaming frequency were observed. Descriptive norms are robust predictors of pregaming behavior, for both genders and across levels of several potential moderators. Future research seeking to understand pregaming behavior should consider descriptive norms, as well as personal attitudes and identification with student peers, as targets of interventions designed to reduce pregaming.

  10. Using the RxNorm web services API for quality assurance purposes.

    PubMed

    Peters, Lee; Bodenreider, Olivier

    2008-11-06

    Auditing large, rapidly evolving terminological systems is still a challenge. In the case of RxNorm, a standardized nomenclature for clinical drugs, we argue that quality assurance processes can benefit from the recently released application programming interface (API) provided by RxNav. We demonstrate the usefulness of the API by performing a systematic comparison of alternative paths in the RxNorm graph, over several thousands of drug entities. This study revealed potential errors in RxNorm, currently under review. The results also prompted us to modify the implementation of RxNav to navigate the RxNorm graph more accurately. The RxNav web services API used in this experiment is robust and fast.

  11. ESTIMATION OF EXPOSURE DOSES FOR THE SAFE MANAGEMENT OF NORM WASTE DISPOSAL.

    PubMed

    Jeong, Jongtae; Ko, Nak Yul; Cho, Dong-Keun; Baik, Min Hoon; Yoon, Ki-Hoon

    2018-03-16

    Naturally occurring radioactive materials (NORM) wastes with different radiological characteristics are generated in several industries. The appropriate options for NORM waste management including disposal options should be discussed and established based on the act and regulation guidelines. Several studies calculated the exposure dose and mass of NORM waste to be disposed in landfill site by considering the activity concentration level and exposure dose. In 2012, the Korean government promulgated an act on the safety control of NORM around living environments to protect human health and the environment. For the successful implementation of this act, we suggest a reference design for a landfill for the disposal of NORM waste. Based on this reference landfill, we estimate the maximum exposure doses and the relative impact of each pathway to exposure dose for three scenarios: a reference scenario, an ingestion pathway exclusion scenario, and a low leach rate scenario. Also, we estimate the possible quantity of NORM waste disposal into a landfill as a function of the activity concentration level of U series, Th series and 40K and two kinds of exposure dose levels, 1 and 0.3 mSv/y. The results of this study can be used to support the establishment of technical bases of the management strategy for the safe disposal of NORM waste.

  12. Reliance on God, Prayer, and Religion Reduces Influence of Perceived Norms on Drinking

    PubMed Central

    Neighbors, Clayton; Brown, Garrett A.; Dibello, Angelo M.; Rodriguez, Lindsey M.; Foster, Dawn W.

    2013-01-01

    Objective: Previous research has shown that perceived social norms are among the strongest predictors of drinking among young adults. Research has also consistently found religiousness to be protective against risk and negative health behaviors. The present research evaluates the extent to which reliance on God, prayer, and religion moderates the association between perceived social norms and drinking. Method: Participants (n = 1,124 undergraduate students) completed a cross-sectional survey online, which included measures of perceived norms, religious values, and drinking. Perceived norms were assessed by asking participants their perceptions of typical student drinking. Drinking outcomes included drinks per week, drinking frequency, and typical quantity consumed. Results: Regression analyses indicated that religiousness and perceived norms had significant unique associations in opposite directions for all three drinking outcomes. Significant interactions were evident between religiousness and perceived norms in predicting drinks per week, frequency, and typical quantity. In each case, the interactions indicated weaker associations between norms and drinking among those who assigned greater importance to religiousness. Conclusions: The extent of the relationship between perceived social norms and drinking was buffered by the degree to which students identified with religiousness. A growing body of literature has shown interventions including personalized feedback regarding social norms to be an effective strategy in reducing drinking among college students. The present research suggests that incorporating religious or spiritual values into student interventions may be a promising direction to pursue. PMID:23490564

  13. Perceived social norms and eating behaviour: An evaluation of studies and future directions.

    PubMed

    Robinson, Eric

    2015-12-01

    Social norms refer to what most people typically do or approve of. There has been some suggestion that perceived social norms may be an important influence on eating behaviour. We and others have shown that perceived social norms relating to very specific contexts can influence food intake (the amount of food consumed in a single sitting) in those contexts; these studies have predominantly sampled young female adults. Less research has examined whether perceived social norms predict dietary behaviour (the types of food people eat on a day to day basis); here, most evidence comes from cross-sectional studies, which have a number of limitations. A small number of intervention studies have started to explore whether perceived social norms can be used to encourage healthier eating with mixed results. The influence that perceived social norms have on objective measures of eating behaviour now needs to be examined using longitudinal methods in order to determine if social norms are an important influence on eating behaviour and/or can be used to promote meaningful behaviour change. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Discriminant locality preserving projections based on L1-norm maximization.

    PubMed

    Zhong, Fujin; Zhang, Jiashu; Li, Defang

    2014-11-01

    Conventional discriminant locality preserving projection (DLPP) is a dimensionality reduction technique based on manifold learning, which has demonstrated good performance in pattern recognition. However, because its objective function is based on the distance criterion using L2-norm, conventional DLPP is not robust to outliers which are present in many applications. This paper proposes an effective and robust DLPP version based on L1-norm maximization, which learns a set of local optimal projection vectors by maximizing the ratio of the L1-norm-based locality preserving between-class dispersion and the L1-norm-based locality preserving within-class dispersion. The proposed method is proven to be feasible and also robust to outliers while overcoming the small sample size problem. The experimental results on artificial datasets, Binary Alphadigits dataset, FERET face dataset and PolyU palmprint dataset have demonstrated the effectiveness of the proposed method.

  15. Eating for Two? Protocol of an Exploratory Survey and Experimental Study on Social Norms and Norm-Based Messages Influencing European Pregnant and Non-pregnant Women’s Eating Behavior

    PubMed Central

    Bevelander, Kirsten E.; Herte, Katharina; Kakoulakis, Catherine; Sanguino, Inés; Tebbe, Anna-Lena; Tünte, Markus R.

    2018-01-01

    The social context is an important factor underlying unhealthy eating behavior and the development of inappropriate weight gain. Evidence is accumulating that powerful social influences can also be used as a tool to impact people’s eating behavior in a positive manner. Social norm-based messages have potential to steer people in making healthier food choices. The research field on nutritional social norms is still emerging and more research is needed to gain insights into why some people adhere to social norms whereas others do not. There are indications stemming from empirical studies on social eating behavior that this may be due to ingratiation purposes and uncertainty reduction. That is, people match their eating behavior to that of the norm set by their eating companion(s) in order to blend in and be part of the group. In this project, we explore nutritional social norms among pregnant women. This population is particularly interesting because they are often subject to unsolicited advice and experience social pressure from their environment. In addition, their pregnancy affects their body composition, eating pattern, and psychosocial status. Pregnancy provides an important window of opportunity to impact health of pregnant women and their child. Nevertheless, the field of nutritional social norms among pregnant women is understudied and more knowledge is needed on whether pregnant women use guidelines from their social environment for their own eating behavior. In this project we aim to fill this research gap by means of an exploratory survey (Study 1) assessing information about social expectations, (mis)perceived social norms and the role of different reference groups such as other pregnant women, family, and friends. In addition, we conduct an online experiment (Study 2) testing to what extent pregnant women are susceptible to social norm-based messages compared to non-pregnant women. Moreover, possible moderators are explored which might impact women

  16. Experiments with conjugate gradient algorithms for homotopy curve tracking

    NASA Technical Reports Server (NTRS)

    Irani, Kashmira M.; Ribbens, Calvin J.; Watson, Layne T.; Kamat, Manohar P.; Walker, Homer F.

    1991-01-01

    There are algorithms for finding zeros or fixed points of nonlinear systems of equations that are globally convergent for almost all starting points, i.e., with probability one. The essence of all such algorithms is the construction of an appropriate homotopy map and then tracking some smooth curve in the zero set of this homotopy map. HOMPACK is a mathematical software package implementing globally convergent homotopy algorithms with three different techniques for tracking a homotopy zero curve, and has separate routines for dense and sparse Jacobian matrices. The HOMPACK algorithms for sparse Jacobian matrices use a preconditioned conjugate gradient algorithm for the computation of the kernel of the homotopy Jacobian matrix, a required linear algebra step for homotopy curve tracking. Here, variants of the conjugate gradient algorithm are implemented in the context of homotopy curve tracking and compared with Craig's preconditioned conjugate gradient method used in HOMPACK. The test problems used include actual large scale, sparse structural mechanics problems.

  17. Jimmy's Baby Doll and Jenny's Truck: Young Children's Reasoning about Gender Norms

    ERIC Educational Resources Information Center

    Conry-Murray, Clare; Turiel, Elliot

    2012-01-01

    To assess the flexibility of reasoning about gender, children ages 4, 6, and 8 years (N = 72) were interviewed about gender norms when different domains were highlighted. The majority of participants at all ages judged a reversal of gender norms in a different cultural context to be acceptable. They also judged gender norms as a matter of personal…

  18. The Effect of Descriptive Norms on Pregaming Frequency: Tests of Five Moderators

    PubMed Central

    Merrill, Jennifer E.; Kenney, Shannon R.; Carey, Kate B.

    2016-01-01

    Background Pregaming is highly prevalent on college campuses and associated with heightened levels of intoxication and risk of alcohol consequences. However, research examining the correlates of pregaming behavior is limited. Descriptive norms (i.e., perceptions about the prevalence or frequency of a behavior) are reliable and comparatively strong predictors of general drinking behavior, with recent evidence indicating that they are also associated with pregaming. Objectives We tested the hypothesis that higher descriptive norms for pregaming frequency would be associated with personal pregaming frequency. We also tested whether this effect would be stronger in the context of several theory-based moderators: female gender, higher injunctive norms (i.e., perceptions of others' attitudes toward a particular behavior), a more positive attitude toward pregaming, a stronger sense of identification with the drinking habits of other students, and stronger social comparison tendencies. Methods College student drinkers (N=198, 63% female) participated in an online survey assessing frequency of pregaming, descriptive norms, and hypothesized moderators. Results A multiple regression model revealed that higher descriptive norms, a more positive attitude toward pregaming, and stronger peer identification were significantly associated with greater pregaming frequency among drinkers. However, no moderators of the association between descriptive norms and pregaming frequency were observed. Conclusions/Importance Descriptive norms are robust predictors of pregaming behavior, for both genders and across levels of several potential moderators. Future research seeking to understand pregaming behavior should consider descriptive norms, as well as personal attitudes and identification with student peers, as targets of interventions designed to reduce pregaming. PMID:27070494

  19. Young children's inclusion decisions in moral and social-conventional group norm contexts.

    PubMed

    Rizzo, Michael T; Cooley, Shelby; Elenbaas, Laura; Killen, Melanie

    2018-01-01

    Being a member of a peer group involves making decisions about whom to include in or exclude from the group. Sometimes these decisions are related to whether members of the group support or challenge the norms of the group. To examine how young children weigh concerns for group norms and group membership in both moral and social-conventional norm contexts, children (3- to 6-year-olds; N=73) were asked to decide between including an ingroup member who challenged the group's norm or an outgroup member who supported the norm. Groups held either moral (equal or unequal resource allocation) or social-conventional (traditional or nontraditional) norms. In the moral contexts, children were more likely to include the peer who advocated for the moral concern for equality regardless of the peer's group membership or their group's specific norm. In the social-conventional contexts, however, children were more likely to include the peer who advocated for the conventional concern for maintaining traditions but only at the group-specific level. Furthermore, with age children increasingly based their inclusion decisions on normative concerns, rather than on group membership concerns, and differed in their inclusion decisions for ingroups and outgroups. Finally, children reasoned about their decisions by referencing concerns for fairness, group norms, and group membership, suggesting that preschool children weigh multiple concerns when deciding whom to include in their groups. Overall, the current study revealed differences in how preschool children weigh moral and social-conventional concerns in intergroup contexts. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. The Justice of Need and the Activation of Humanitarian Norms

    ERIC Educational Resources Information Center

    Schwartz, Shalom

    1975-01-01

    Outlines the process leading from the perception of need to altruistic behavior arguing that internalized humanitarian norms mediate this process and that when these norms are activated, behavior may be motivated by the justice of need. Suggestions for further research are made. (Author/AM)

  1. Social Support and Peer Norms Scales for Physical Activity in Adolescents

    PubMed Central

    Ling, Jiying; Robbins, Lorraine B.; Resnicow, Ken; Bakhoya, Marion

    2015-01-01

    Objectives To evaluate psychometric properties of a Social Support and Peer Norms Scale in 5th-7th grade urban girls. Methods Baseline data from 509 girls and test-retest data from another 94 girls in the Midwestern US were used. Results Cronbach's alpha was .83 for the Social Support Scale and .72 for the Peer Norms Scale, whereas test-re-test reliability was .78 for both scales. Exploratory factor analysis suggested a single factor structure for the Social Support Scale, and a 3-factor structure for the Peer Norms Scale. Social support was correlated with accelerometer-measured physical activity (r = .13, p = .006), and peer norms (r = .50, p < .0001). Conclusions Both scales have adequate psychometric properties. PMID:25207514

  2. Hybrid normed ideal perturbations of n-tuples of operators I

    NASA Astrophysics Data System (ADS)

    Voiculescu, Dan-Virgil

    2018-06-01

    In hybrid normed ideal perturbations of n-tuples of operators, the normed ideal is allowed to vary with the component operators. We begin extending to this setting the machinery we developed for normed ideal perturbations based on the modulus of quasicentral approximation and an adaptation of our non-commutative generalization of the Weyl-von Neumann theorem. For commuting n-tuples of hermitian operators, the modulus of quasicentral approximation remains essentially the same when Cn- is replaced by a hybrid n-tuple Cp1,…- , … , Cpn- , p1-1 + ⋯ + pn-1 = 1. The proof involves singular integrals of mixed homogeneity.

  3. Team behavioral norms: a shared vision for a healthy patient care workplace.

    PubMed

    Parsons, Mickey L; Clark, Paul; Marshall, Michelle; Cornett, Patricia A

    2007-01-01

    Leaders are bombarded with healthy workplace articles and advice. This article outlines a strategy for laying the foundation for healthy patient care workplaces at the pivotal unit level. This process facilitates the nursing unit staff to create and implement a shared vision for staff working relationships. Fourteen acute care hospital units, all participants in a healthy workplace intervention, were selected for this analysis because they chose team behavioral norms as a top priority to begin to implement their vision for a desired future for their units, a healthy workplace. These units developed specific team behavioral norms for their expectations of each other. The findings revealed 3 major norm themes and attributes: norms for effective communication, positive attitude, and accountability. Attributes of each norm are described to assist nurses to positively influence their core unit work culture.

  4. On functional determinants of matrix differential operators with multiple zero modes

    NASA Astrophysics Data System (ADS)

    Falco, G. M.; Fedorenko, Andrei A.; Gruzberg, Ilya A.

    2017-12-01

    We generalize the method of computing functional determinants with a single excluded zero eigenvalue developed by McKane and Tarlie to differential operators with multiple zero eigenvalues. We derive general formulas for such functional determinants of r× r matrix second order differential operators O with 0 < n ≤slant 2r linearly independent zero modes. We separately discuss the cases of the homogeneous Dirichlet boundary conditions, when the number of zero modes cannot exceed r, and the case of twisted boundary conditions, including the periodic and anti-periodic ones, when the number of zero modes is bounded above by 2r. In all cases the determinants with excluded zero eigenvalues can be expressed only in terms of the n zero modes and other r-n or 2r-n (depending on the boundary conditions) solutions of the homogeneous equation O h=0 , in the spirit of Gel’fand-Yaglom approach. In instanton calculations, the contribution of the zero modes is taken into account by introducing the so-called collective coordinates. We show that there is a remarkable cancellation of a factor (involving scalar products of zero modes) between the Jacobian of the transformation to the collective coordinates and the functional fluctuation determinant with excluded zero eigenvalues. This cancellation drastically simplifies instanton calculations when one uses our formulas.

  5. Associations of Perceived Norms With Intentions to Learn Genomic Sequencing Results: Roles for Attitudes and Ambivalence

    PubMed Central

    Reid, Allecia E.; Taber, Jennifer M.; Ferrer, Rebecca A.; Biesecker, Barbara B.; Lewis, Katie L.; Biesecker, Leslie G.; Klein, William M. P.

    2018-01-01

    Objective Genomic sequencing is becoming increasingly accessible, highlighting the need to understand the social and psychological factors that drive interest in receiving testing results. These decisions may depend on perceived descriptive norms (how most others behave) and injunctive norms (what is approved of by others). We predicted that descriptive norms would be directly associated with intentions to learn genomic sequencing results, whereas injunctive norms would be associated indirectly, via attitudes. These differential associations with intentions versus attitudes were hypothesized to be strongest when individuals held ambivalent attitudes toward obtaining results. Methods Participants enrolled in a genomic sequencing trial (n=372) reported intentions to learn medically actionable, non-medically actionable, and carrier sequencing results. Descriptive norms items referenced other study participants. Injunctive norms were analyzed separately for close friends and family members. Attitudes, attitudinal ambivalence, and sociodemographic covariates were also assessed. Results In structural equation models, both descriptive norms and friend injunctive norms were associated with intentions to receive all sequencing results (ps<.004). Attitudes consistently mediated all friend injunctive norms-intentions associations, but not the descriptive norms-intentions associations. Attitudinal ambivalence moderated the association between friend injunctive norms (p≤.001), but not descriptive norms (p=.16), and attitudes. Injunctive norms were significantly associated with attitudes when ambivalence was high, but were unrelated when ambivalence was low. Results replicated for family injunctive norms. Conclusions Descriptive and injunctive norms play roles in genomic sequencing decisions. Considering mediators and moderators of these processes enhances ability to optimize use of normative information to support informed decision making. PMID:29745680

  6. Quantifying social norms: by coupling the ecosystem management concept and semi-quantitative sociological methods

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Xu, H.

    2012-12-01

    Over recent decades, human-induced environmental changes have steadily and rapidly grown in intensity and impact to where they now often exceed natural impacts. As one of important components of human activities, social norms play key roles in environmental and natural resources management. But the lack of relevant quantitative data about social norms greatly limits our scientific understanding of the complex linkages between humans and nature, and hampers our solving of pressing environmental and social problems. In this study, we built a quantified method by coupling the ecosystem management concept, semi-quantitative sociological methods and mathematical statistics. We got the quantified value of social norms from two parts, whether the content of social norms coincide with the concept of ecosystem management (content value) and how about the performance after social norms were put into implementation (implementation value) . First, we separately identified 12 core elements of ecosystem management and 16 indexes of social norms, and then matched them one by one. According to their matched degree, we got the content value of social norms. Second, we selected 8 key factors that can represent the performance of social norms after they were put into implementation, and then we got the implementation value by Delph method. Adding these two parts values, we got the final value of each social norms. Third, we conducted a case study in Heihe river basin, the second largest inland river in China, by selecting 12 official edicts related to the river basin ecosystem management of Heihe River Basin. By doing so, we first got the qualified data of social norms which can be directly applied to the research that involved observational or experimental data collection of natural processes. Second, each value was supported by specific contents, so it can assist creating a clear road map for building or revising management and policy guidelines. For example, in this case study

  7. The Constructive, Destructive, and Reconstructive Power of Social Norms: Reprise.

    PubMed

    Schultz, P Wesley; Nolan, Jessica M; Cialdini, Robert B; Goldstein, Noah J; Griskevicius, Vladas

    2018-03-01

    The influence of social norms on behavior has been a longstanding storyline within social psychology. Our 2007 Psychological Science publication presented a new rendition of this classic telling. The reported field experiment showed that social norms could be leveraged to promote residential energy conservation, but importantly, the descriptive norm was shown to increase consumption for low-consuming households. This potential destructive effect of social norms was eliminated with the addition of an injunctive message of social approval for using less energy. The article is among the 30 most-cited articles across all APS publications, which we attribute to our methodology, which measured real behavior in a large-scale field experiment and to several circumstances associated with the timing of the work. The article coincided with the explosion of social media, the emergence of behavioral economics, and a heightened level of concern about climate change. These contemporaneous activities set the stage for our work and for its high degree of citation.

  8. Nonlinear study of the parallel velocity/tearing instability using an implicit, nonlinear resistive MHD solver

    NASA Astrophysics Data System (ADS)

    Chacon, L.; Finn, J. M.; Knoll, D. A.

    2000-10-01

    Recently, a new parallel velocity instability has been found.(J. M. Finn, Phys. Plasmas), 2, 12 (1995) This mode is a tearing mode driven unstable by curvature effects and sound wave coupling in the presence of parallel velocity shear. Under such conditions, linear theory predicts that tearing instabilities will grow even in situations in which the classical tearing mode is stable. This could then be a viable seed mechanism for the neoclassical tearing mode, and hence a non-linear study is of interest. Here, the linear and non-linear stages of this instability are explored using a fully implicit, fully nonlinear 2D reduced resistive MHD code,(L. Chacon et al), ``Implicit, Jacobian-free Newton-Krylov 2D reduced resistive MHD nonlinear solver,'' submitted to J. Comput. Phys. (2000) including viscosity and particle transport effects. The nonlinear implicit time integration is performed using the Newton-Raphson iterative algorithm. Krylov iterative techniques are employed for the required algebraic matrix inversions, implemented Jacobian-free (i.e., without ever forming and storing the Jacobian matrix), and preconditioned with a ``physics-based'' preconditioner. Nonlinear results indicate that, for large total plasma beta and large parallel velocity shear, the instability results in the generation of large poloidal shear flows and large magnetic islands even in regimes when the classical tearing mode is absolutely stable. For small viscosity, the time asymptotic state can be turbulent.

  9. Defectors, not norm violators, are punished by third-parties.

    PubMed

    Bone, Jonathan; Silva, Antonio S; Raihani, Nichola J

    2014-07-01

    Punishment of defectors and cooperators is prevalent when their behaviour deviates from the social norm. Why atypical behaviour is more likely to be punished than typical behaviour remains unclear. One possible proximate explanation is that individuals simply dislike norm violators. However, an alternative possibility exists: individuals may be more likely to punish atypical behaviour, because the cost of punishment generally increases with the number of individuals that are punished. We used a public goods game with third-party punishment to test whether punishment of defectors was reduced when defecting was typical, as predicted if punishment is responsive to norm violation. The cost of punishment was fixed, regardless of the number of players punished, meaning that it was not more costly to punish typical, relative to atypical, behaviour. Under these conditions, atypical behaviour was not punished more often than typical behaviour. In fact, most punishment was targeted at defectors, irrespective of whether defecting was typical or atypical. We suggest that the reduced punishment of defectors when they are common might often be explained in terms of the costs to the punisher, rather than responses to norm violators.

  10. Profiling structured product labeling with NDF-RT and RxNorm

    PubMed Central

    2012-01-01

    Background Structured Product Labeling (SPL) is a document markup standard approved by Health Level Seven (HL7) and adopted by United States Food and Drug Administration (FDA) as a mechanism for exchanging drug product information. The SPL drug labels contain rich information about FDA approved clinical drugs. However, the lack of linkage to standard drug ontologies hinders their meaningful use. NDF-RT (National Drug File Reference Terminology) and NLM RxNorm as standard drug ontology were used to standardize and profile the product labels. Methods In this paper, we present a framework that intends to map SPL drug labels with existing drug ontologies: NDF-RT and RxNorm. We also applied existing categorical annotations from the drug ontologies to classify SPL drug labels into corresponding classes. We established the classification and relevant linkage for SPL drug labels using the following three approaches. First, we retrieved NDF-RT categorical information from the External Pharmacologic Class (EPC) indexing SPLs. Second, we used the RxNorm and NDF-RT mappings to classify and link SPLs with NDF-RT categories. Third, we profiled SPLs using RxNorm term type information. In the implementation process, we employed a Semantic Web technology framework, in which we stored the data sets from NDF-RT and SPLs into a RDF triple store, and executed SPARQL queries to retrieve data from customized SPARQL endpoints. Meanwhile, we imported RxNorm data into MySQL relational database. Results In total, 96.0% SPL drug labels were mapped with NDF-RT categories whereas 97.0% SPL drug labels are linked to RxNorm codes. We found that the majority of SPL drug labels are mapped to chemical ingredient concepts in both drug ontologies whereas a relatively small portion of SPL drug labels are mapped to clinical drug concepts. Conclusions The profiling outcomes produced by this study would provide useful insights on meaningful use of FDA SPL drug labels in clinical applications through

  11. Profiling structured product labeling with NDF-RT and RxNorm.

    PubMed

    Zhu, Qian; Jiang, Guoqian; Chute, Christopher G

    2012-12-20

    Structured Product Labeling (SPL) is a document markup standard approved by Health Level Seven (HL7) and adopted by United States Food and Drug Administration (FDA) as a mechanism for exchanging drug product information. The SPL drug labels contain rich information about FDA approved clinical drugs. However, the lack of linkage to standard drug ontologies hinders their meaningful use. NDF-RT (National Drug File Reference Terminology) and NLM RxNorm as standard drug ontology were used to standardize and profile the product labels. In this paper, we present a framework that intends to map SPL drug labels with existing drug ontologies: NDF-RT and RxNorm. We also applied existing categorical annotations from the drug ontologies to classify SPL drug labels into corresponding classes. We established the classification and relevant linkage for SPL drug labels using the following three approaches. First, we retrieved NDF-RT categorical information from the External Pharmacologic Class (EPC) indexing SPLs. Second, we used the RxNorm and NDF-RT mappings to classify and link SPLs with NDF-RT categories. Third, we profiled SPLs using RxNorm term type information. In the implementation process, we employed a Semantic Web technology framework, in which we stored the data sets from NDF-RT and SPLs into a RDF triple store, and executed SPARQL queries to retrieve data from customized SPARQL endpoints. Meanwhile, we imported RxNorm data into MySQL relational database. In total, 96.0% SPL drug labels were mapped with NDF-RT categories whereas 97.0% SPL drug labels are linked to RxNorm codes. We found that the majority of SPL drug labels are mapped to chemical ingredient concepts in both drug ontologies whereas a relatively small portion of SPL drug labels are mapped to clinical drug concepts. The profiling outcomes produced by this study would provide useful insights on meaningful use of FDA SPL drug labels in clinical applications through standard drug ontologies such as NDF-RT and

  12. Evaluating theory-based evaluation: information, norms, and adherence.

    PubMed

    Jacobs, W Jake; Sisco, Melissa; Hill, Dawn; Malter, Frederic; Figueredo, Aurelio José

    2012-08-01

    Programmatic social interventions attempt to produce appropriate social-norm-guided behavior in an open environment. A marriage of applicable psychological theory, appropriate program evaluation theory, and outcome of evaluations of specific social interventions assures the acquisition of cumulative theory and the production of successful social interventions--the marriage permits us to advance knowledge by making use of both success and failures. We briefly review well-established principles within the field of program evaluation, well-established processes involved in changing social norms and social-norm adherence, the outcome of several program evaluations focusing on smoking prevention, pro-environmental behavior, and rape prevention and, using the principle of learning from our failures, examine why these programs often do not perform as expected. Finally, we discuss the promise of learning from our collective experiences to develop a cumulative science of program evaluation and to improve the performance of extant and future interventions. Copyright © 2012. Published by Elsevier Ltd.

  13. Injunctive Norms and Problem Gambling among College Students

    PubMed Central

    Lostutter, Ty W.; Whiteside, Ursula; Fossos, Nicole; Walker, Denise D.; Larimer, Mary E.

    2010-01-01

    Two studies examined the relationships among injunctive norms and college student gambling. In study 1 we evaluated the accuracy of perceptions of other students’ approval of gambling and the relationship between perceived approval and gambling behavior. In study 2 we evaluated gambling behavior as a function of perceptions of approval of other students, friends, and family. In study 1, which included 2524 college students, perceptions of other students’ approval of gambling were found to be overestimated and were negatively associated with gambling behavior. The results of study 2, which included 565 college students, replicated the findings of study 1 and revealed positive associations between gambling behavior and perceived approval of friends and family. Results highlight the complexity of injunctive norms and the importance of considering the reference group (e.g., peers, friends, family members) in their evaluation. Results also encourage caution in considering the incorporation of injunctive norms in prevention and intervention approaches. PMID:17394053

  14. Anisotropic norm-oriented mesh adaptation for a Poisson problem

    NASA Astrophysics Data System (ADS)

    Brèthes, Gautier; Dervieux, Alain

    2016-10-01

    We present a novel formulation for the mesh adaptation of the approximation of a Partial Differential Equation (PDE). The discussion is restricted to a Poisson problem. The proposed norm-oriented formulation extends the goal-oriented formulation since it is equation-based and uses an adjoint. At the same time, the norm-oriented formulation somewhat supersedes the goal-oriented one since it is basically a solution-convergent method. Indeed, goal-oriented methods rely on the reduction of the error in evaluating a chosen scalar output with the consequence that, as mesh size is increased (more degrees of freedom), only this output is proven to tend to its continuous analog while the solution field itself may not converge. A remarkable quality of goal-oriented metric-based adaptation is the mathematical formulation of the mesh adaptation problem under the form of the optimization, in the well-identified set of metrics, of a well-defined functional. In the new proposed formulation, we amplify this advantage. We search, in the same well-identified set of metrics, the minimum of a norm of the approximation error. The norm is prescribed by the user and the method allows addressing the case of multi-objective adaptation like, for example in aerodynamics, adaptating the mesh for drag, lift and moment in one shot. In this work, we consider the basic linear finite-element approximation and restrict our study to L2 norm in order to enjoy second-order convergence. Numerical examples for the Poisson problem are computed.

  15. A numerical method to solve the 1D and the 2D reaction diffusion equation based on Bessel functions and Jacobian free Newton-Krylov subspace methods

    NASA Astrophysics Data System (ADS)

    Parand, K.; Nikarya, M.

    2017-11-01

    In this paper a novel method will be introduced to solve a nonlinear partial differential equation (PDE). In the proposed method, we use the spectral collocation method based on Bessel functions of the first kind and the Jacobian free Newton-generalized minimum residual (JFNGMRes) method with adaptive preconditioner. In this work a nonlinear PDE has been converted to a nonlinear system of algebraic equations using the collocation method based on Bessel functions without any linearization, discretization or getting the help of any other methods. Finally, by using JFNGMRes, the solution of the nonlinear algebraic system is achieved. To illustrate the reliability and efficiency of the proposed method, we solve some examples of the famous Fisher equation. We compare our results with other methods.

  16. Correction of electrode modelling errors in multi-frequency EIT imaging.

    PubMed

    Jehl, Markus; Holder, David

    2016-06-01

    The differentiation of haemorrhagic from ischaemic stroke using electrical impedance tomography (EIT) requires measurements at multiple frequencies, since the general lack of healthy measurements on the same patient excludes time-difference imaging methods. It has previously been shown that the inaccurate modelling of electrodes constitutes one of the largest sources of image artefacts in non-linear multi-frequency EIT applications. To address this issue, we augmented the conductivity Jacobian matrix with a Jacobian matrix with respect to electrode movement. Using this new algorithm, simulated ischaemic and haemorrhagic strokes in a realistic head model were reconstructed for varying degrees of electrode position errors. The simultaneous recovery of conductivity spectra and electrode positions removed most artefacts caused by inaccurately modelled electrodes. Reconstructions were stable for electrode position errors of up to 1.5 mm standard deviation along both surface dimensions. We conclude that this method can be used for electrode model correction in multi-frequency EIT.

  17. A set of parallel, implicit methods for a reconstructed discontinuous Galerkin method for compressible flows on 3D hybrid grids

    DOE PAGES

    Xia, Yidong; Luo, Hong; Frisbey, Megan; ...

    2014-07-01

    A set of implicit methods are proposed for a third-order hierarchical WENO reconstructed discontinuous Galerkin method for compressible flows on 3D hybrid grids. An attractive feature in these methods are the application of the Jacobian matrix based on the P1 element approximation, resulting in a huge reduction of memory requirement compared with DG (P2). Also, three approaches -- analytical derivation, divided differencing, and automatic differentiation (AD) are presented to construct the Jacobian matrix respectively, where the AD approach shows the best robustness. A variety of compressible flow problems are computed to demonstrate the fast convergence property of the implemented flowmore » solver. Furthermore, an SPMD (single program, multiple data) programming paradigm based on MPI is proposed to achieve parallelism. The numerical results on complex geometries indicate that this low-storage implicit method can provide a viable and attractive DG solution for complicated flows of practical importance.« less

  18. Establishing a NORM based radiation calibration facility.

    PubMed

    Wallace, J

    2016-05-01

    An environmental radiation calibration facility has been constructed by the Radiation and Nuclear Sciences unit of Queensland Health at the Forensic and Scientific Services Coopers Plains campus in Brisbane. This facility consists of five low density concrete pads, spiked with a NORM source, to simulate soil and effectively provide a number of semi-infinite uniformly distributed sources for improved energy response calibrations of radiation equipment used in NORM measurements. The pads have been sealed with an environmental epoxy compound to restrict radon loss and so enhance the quality of secular equilibrium achieved. Monte Carlo models (MCNP),used to establish suitable design parameters and identify appropriate geometric correction factors linking the air kerma measured above these calibration pads to that predicted for an infinite plane using adjusted ICRU53 data, are discussed. Use of these correction factors as well as adjustments for cosmic radiation and the impact of surrounding low levels of NORM in the soil, allows for good agreement between the radiation fields predicted and measured above the pads at both 0.15 m and 1 m. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Alcohol Expectancies, Perceived Norms and Drinking Behavior among College Students: Examining the Reciprocal Determinism Hypothesis

    PubMed Central

    Wardell, Jeffrey D.; Read, Jennifer P.

    2012-01-01

    Social learning mechanisms, such as descriptive norms for drinking behavior (norms) and positive alcohol expectancies (PAEs), play a major role in college student alcohol use. According to the principle of reciprocal determinism (Bandura, 1977), norms and PAEs should be reciprocally associated with alcohol use, each influencing one another over time. However, the nature of these prospective relationships for college students is in need of further investigation. This study provided the first examination of the unique reciprocal associations among norms, PAEs, and drinking together in a single model. PAEs become more stable with age, whereas norms are likely to be more dynamic upon college entry. Thus, we hypothesized that alcohol use would show stronger reciprocal associations with norms than with PAEs for college students. Students (N=557; 67% female) completed online measures of PAEs, norms and quantity and frequency of alcohol use in September of their first (T1), second (T2), and third (T3) years of college. Reciprocal associations were analyzed using a cross-lagged panel design. PAEs had unidirectional influences on frequency and quantity of alcohol use, with no prospective effects from alcohol use to PAEs. Reciprocal associations were observed between norms and alcohol use, but only for quantity and not frequency. Specifically, drinking quantity prospectively predicted quantity norms and quantity norms prospectively predicted drinking quantity. This effect was observed across both years in the model. These findings support the reciprocal determinism hypothesis for norms but not for PAEs in college students, and may help to inform norm-based interventions. PMID:23088403

  20. Alcohol expectancies, perceived norms, and drinking behavior among college students: examining the reciprocal determinism hypothesis.

    PubMed

    Wardell, Jeffrey D; Read, Jennifer P

    2013-03-01

    Social learning mechanisms, such as descriptive norms for drinking behavior (norms) and positive alcohol expectancies (PAEs), play a major role in college student alcohol use. According to the principle of reciprocal determinism (Bandura, 1977), norms and PAEs should be reciprocally associated with alcohol use, each influencing one another over time. However, the nature of these prospective relationships for college students is in need of further investigation. This study provided the first examination of the unique reciprocal associations among norms, PAEs, and drinking together in a single model. PAEs become more stable with age, whereas norms are likely to be more dynamic upon college entry. Thus, we hypothesized that alcohol use would show stronger reciprocal associations with norms than with PAEs for college students. Students (N = 557; 67% women) completed online measures of PAEs, norms, and quantity and frequency of alcohol use in September of their first (T1), second (T2), and third (T3) years of college. Reciprocal associations were analyzed using a cross-lagged panel design. PAEs had unidirectional influences on frequency and quantity of alcohol use, with no prospective effects from alcohol use to PAEs. Reciprocal associations were observed between norms and alcohol use, but only for quantity and not for frequency. Specifically, drinking quantity prospectively predicted quantity norms and quantity norms prospectively predicted drinking quantity. This effect was observed across both years in the model. These findings support the reciprocal determinism hypothesis for norms but not for PAEs in college students and may help to inform norm-based interventions. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  1. Social Norms Information Enhances the Efficacy of an Appearance-based Sun Protection Intervention

    PubMed Central

    Kulik, James A; Butler, Heather; Gerrard, Meg; Gibbons, Frederick X; Mahler, Heike

    2008-01-01

    This experiment examined whether the efficacy of an appearance-based sun protection intervention could be enhanced by the addition of social norms information. Southern California college students (N=125, predominantly female) were randomly assigned to either an appearance-based sun protection intervention-that consisted of a photograph depicting underlying sun damage to their skin (UV photo) and information about photoaging or to a control condition. Those assigned to the intervention were further randomized to receive information about what one should do to prevent photoaging (injunctive norms information), information about the number of their peers who currently use regular sun protection (descriptive norms information), both injunctive and descriptive norms information, or neither type of norms information. The results demonstrated that those who received the UV Photo/photoaging information intervention expressed greater sun protection intentions and subsequently reported greater sun protection behaviors than did controls. Further, the addition of both injunctive and descriptive norms information increased self-reported sun protection behaviors during the subsequent month. PMID:18448221

  2. EEG Arousal Norms by Age

    PubMed Central

    Bonnet, Michael H.; Arand, Donna L.

    2007-01-01

    Study Objectives: Brief arousals have been systematically scored during sleep for more than 20 years. Despite significant knowledge concerning the importance of arousals for the sleep process in normal subjects and patients, comprehensive age norms have not been published. Methods: Seventy-six normal subjects (40 men) without sleep apnea or periodic limb movements of sleep, aged 18 to 70 years, slept in the sleep laboratory for 1 or more nights. Sleep and arousal data were scored by the same scorer for the first night (comparable to clinical polysomnograms) and summarized by age decade. Results: There were no statistically significant differences for sex or interaction of sex by age (p > .5 for both). The mean arousal index increased as a function of age. Newman-Keuls comparisons (.05) showed arousal index in the 18- to 20-year and 21- to 30-year age groups to be significantly less than the arousal index in the other 4 age groups. Arousal index in the 31-to 40-year and 41-to 50-year groups was significantly less than the arousal index in the older groups. The arousal index was significantly negatively correlated with total sleep time and all sleep stages (positive correlation with stage 1 and wake). Conclusions: Brief arousals are an integral component of the sleep process. They increase with other electroencephalographic markers as a function of age. They are highly correlated with traditional sleep-stage amounts and are related to major demographic variables. Age-related norms may make identification of pathologic arousal easier. Citations: Bonnet M; Arand D. EEG Arousal Norms by Age. J Clin Sleep Med 2007;3(3):271–274 PMID:17561594

  3. SU-F-I-51: CT/MR Image Deformation: The Clinical Assessment QA in Target Delineation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, C; Chen, Y

    Purpose: To study the deformation effects in CT/MR image registration of head and neck (HN) cancers. We present a clinical indication in guiding and simplifying registration procedures of this process while CT images possessed artifacts. Methods: CT/MR image fusion provides better soft tissue contrast in intracranial GTV definition with artifacts. However, whether the fusion process should include the deformation process is questionable and not recommended. We performed CT/MR image registration of a HN patient with tonsil GTV and nodes delineation on Varian Velocity™ system. Both rigid transformation and deformable registration of the same CT/MR imaging data were processed separately. Physician’smore » selection of target delineation was implemented to identify the variations. Transformation matrix was shown with visual identification, as well as the deformation QA numbers and figures were assessed. Results: The deformable CT/MR images were traced with the calculated matrix, both translation and rotational parameters were summarized. In deformable quality QA, the calculated Jacobian matrix was analyzed, which the min/mean/max of 0.73/0/99/1.37, respectively. Jacobian matrix of right neck node was 0.84/1.13/1.41, which present dis-similarity of the nodal area. If Jacobian = 1, the deformation is at the optimum situation. In this case, the deformation results have shown better target delineation for CT/MR deformation than rigid transformation. Though the root-mean-square vector difference is 1.48 mm, with similar rotational components, the cord and vertebrae position were aligned much better in the deformable MR images than the rigid transformation. Conclusion: CT/MR with/without image deformation presents similar image registration matrix; there were significant differentiate the anatomical structures in the region of interest by deformable process. Though vendor suggested only rigid transformation between CT/MR assuming the geometry remain similar, our

  4. Space Junk Norms: US Advantages in Creating a Debris Reducing Outer Space Norm

    DTIC Science & Technology

    2011-05-01

    and White Knight ,” http://www.scaled.com/projects/tierone/ (accessed 25 March 2011). 26 Mike Moore argues that the nearest global competitor to the...formation of norms. 27 For an explanation of the US 2008 ASAT test, see Jamie McIntyre...the Space Age. Baltimore: Johns Hopkins University Press, 1997. McIntyre, Jamie , Suzanne Malveaux and Miles O’Brien. “Navy Missile Hits Dying Spy

  5. Robust L1-norm two-dimensional linear discriminant analysis.

    PubMed

    Li, Chun-Na; Shao, Yuan-Hai; Deng, Nai-Yang

    2015-05-01

    In this paper, we propose an L1-norm two-dimensional linear discriminant analysis (L1-2DLDA) with robust performance. Different from the conventional two-dimensional linear discriminant analysis with L2-norm (L2-2DLDA), where the optimization problem is transferred to a generalized eigenvalue problem, the optimization problem in our L1-2DLDA is solved by a simple justifiable iterative technique, and its convergence is guaranteed. Compared with L2-2DLDA, our L1-2DLDA is more robust to outliers and noises since the L1-norm is used. This is supported by our preliminary experiments on toy example and face datasets, which show the improvement of our L1-2DLDA over L2-2DLDA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. How culture gets embrained: Cultural differences in event-related potentials of social norm violations.

    PubMed

    Mu, Yan; Kitayama, Shinobu; Han, Shihui; Gelfand, Michele J

    2015-12-15

    Humans are unique among all species in their ability to develop and enforce social norms, but there is wide variation in the strength of social norms across human societies. Despite this fundamental aspect of human nature, there has been surprisingly little research on how social norm violations are detected at the neurobiological level. Building on the emerging field of cultural neuroscience, we combine noninvasive electroencephalography (EEG) with a new social norm violation paradigm to examine the neural mechanisms underlying the detection of norm violations and how they vary across cultures. EEG recordings from Chinese and US participants (n = 50) showed consistent negative deflection of event-related potential around 400 ms (N400) over the central and parietal regions that served as a culture-general neural marker of detecting norm violations. The N400 at the frontal and temporal regions, however, was only observed among Chinese but not US participants, illustrating culture-specific neural substrates of the detection of norm violations. Further, the frontal N400 predicted a variety of behavioral and attitudinal measurements related to the strength of social norms that have been found at the national and state levels, including higher culture superiority and self-control but lower creativity. There were no cultural differences in the N400 induced by semantic violation, suggesting a unique cultural influence on social norm violation detection. In all, these findings provided the first evidence, to our knowledge, for the neurobiological foundations of social norm violation detection and its variation across cultures.

  7. How culture gets embrained: Cultural differences in event-related potentials of social norm violations

    PubMed Central

    Mu, Yan; Kitayama, Shinobu; Han, Shihui; Gelfand, Michele J.

    2015-01-01

    Humans are unique among all species in their ability to develop and enforce social norms, but there is wide variation in the strength of social norms across human societies. Despite this fundamental aspect of human nature, there has been surprisingly little research on how social norm violations are detected at the neurobiological level. Building on the emerging field of cultural neuroscience, we combine noninvasive electroencephalography (EEG) with a new social norm violation paradigm to examine the neural mechanisms underlying the detection of norm violations and how they vary across cultures. EEG recordings from Chinese and US participants (n = 50) showed consistent negative deflection of event-related potential around 400 ms (N400) over the central and parietal regions that served as a culture-general neural marker of detecting norm violations. The N400 at the frontal and temporal regions, however, was only observed among Chinese but not US participants, illustrating culture-specific neural substrates of the detection of norm violations. Further, the frontal N400 predicted a variety of behavioral and attitudinal measurements related to the strength of social norms that have been found at the national and state levels, including higher culture superiority and self-control but lower creativity. There were no cultural differences in the N400 induced by semantic violation, suggesting a unique cultural influence on social norm violation detection. In all, these findings provided the first evidence, to our knowledge, for the neurobiological foundations of social norm violation detection and its variation across cultures. PMID:26621713

  8. Creation of Norms for the Purpose of Global Talent Management

    ERIC Educational Resources Information Center

    Hedricks, Cynthia A.; Robie, Chet; Harnisher, John V.

    2008-01-01

    Personality scores were used to construct three databases of global norms. The composition of the three databases varied according to percentage of cases by global region, occupational group, applicant status, and gender of the job candidate. Comparison of personality scores across the three norms databases revealed that the magnitude of the…

  9. Teaching the Sociocultural Norms of an Undergraduate Community of Practice

    ERIC Educational Resources Information Center

    Couper, Graeme; Denny, Heather; Watkins, Annette

    2016-01-01

    The importance of teaching second language learners the pragmatic norms of relevant communities of practice is widely recognised. Familiarisation with these norms is also an important aspect of socialisation for native speakers entering a new community of practice. This study focuses on pragmatic instruction of English as an additional language…

  10. Teachers' Sense of Efficacy: A Self- or Norm-Referenced Construct?

    ERIC Educational Resources Information Center

    Ashton, Patricia; And Others

    1984-01-01

    Two approaches to the measurement of teacher efficacy were investigated to determine whether teachers' sense of self-efficacy is a self-referenced or norm-referenced construct. Two forms of an instrument consisting of 25 teaching problem situations were developed: one required self-referenced responses, while the other required norm-referenced…

  11. Predicting Australian adults' sun-safe behaviour: examining the role of personal and social norms.

    PubMed

    White, Katherine M; Starfelt, Louise C; Young, Ross McD; Hawkes, Anna L; Leske, Stuart; Hamilton, Kyra

    2015-05-01

    To address the scarcity of comprehensive, theory-based research in the Australian context, this study, using a theory of planned behaviour (TPB) framework, investigated the role of personal and social norms to identify the key predictors of adult Australians' sun-safe intentions and behaviour. The study used a prospective design with two waves of data collection, 1 week apart. Participants were 816 adults (48.2% men) aged between 18 and 88 years recruited from urban, regional, and rural areas of Australia. At baseline, participants completed a questionnaire assessing the standard TPB predictors (attitude, subjective norm, and perceived behavioural control [PBC]), past behaviour, behavioural intention, and additional measures of group norm for the referent groups of friends and family, image norm, personal norm, personal choice/responsibility, and Australian identity. Seventy-one per cent of the participants (n = 577) reported on their sun-safe behaviour in the subsequent week. Via path modelling, past behaviour, attitude, group norm (friends), personal norm, and personal choice/responsibility emerged as independent predictors of intentions which, in turn, predicted sun-safe behaviour prospectively. Past behaviour, but not PBC, had direct effects on sun-safe behaviour. The model explained 61.6% and 43.9% of the variance in intention and behaviour, respectively. This study provides support for the use of a comprehensive theoretical decision-making model to explain Australian adults' sun-safe intentions and behaviours and identifies viable targets for health-promoting messages in this high-risk context. Statement of contribution What is already known on this subject? Identifying determinants of sun-safe behaviour is vital in high-risk cancer areas like Australia. For young Australians, friendship group norm is a key influence of intentions and behaviour. Little is known about drivers of sun safety, especially norms, among Australian adults in general. What does this

  12. Complex Relationships Among Masculine Norms and Health/Well-Being Outcomes: Correlation Patterns of the Conformity to Masculine Norms Inventory Subscales

    PubMed Central

    Gerdes, Zachary T.; Levant, Ronald F.

    2017-01-01

    The Conformity to Masculine Norms Inventory (CMNI) is a widely used multidimensional scale. Studies using the CMNI most often report only total scale scores, which are predominantly associated with negative outcomes. Various studies since the CMNI’s inception in 2003 using subscales have reported both positive and negative outcomes. The current content analysis examined studies (N = 17) correlating the 11 subscales with 63 criterion variables across 7 categories. Most findings were consistent with past research using total scale scores that reported negative outcomes. For example, conformity to masculine norms has been inversely related to help-seeking and positively correlated with concerning health variables, such as substance use. Nonetheless, past reliance on total scores has obscured the complexity of associations with the CMNI in that 30% of the findings in the present study reflected positive outcomes, particularly for health promotion. Subscales differed in their relationships with various outcomes: for one subscale they were predominantly positive, but six others were mostly negative. The situational and contextual implications of conformity to masculine norms and their relationships to positive and negative outcomes are discussed. PMID:29219033

  13. Complex Relationships Among Masculine Norms and Health/Well-Being Outcomes: Correlation Patterns of the Conformity to Masculine Norms Inventory Subscales.

    PubMed

    Gerdes, Zachary T; Levant, Ronald F

    2018-03-01

    The Conformity to Masculine Norms Inventory (CMNI) is a widely used multidimensional scale. Studies using the CMNI most often report only total scale scores, which are predominantly associated with negative outcomes. Various studies since the CMNI's inception in 2003 using subscales have reported both positive and negative outcomes. The current content analysis examined studies ( N = 17) correlating the 11 subscales with 63 criterion variables across 7 categories. Most findings were consistent with past research using total scale scores that reported negative outcomes. For example, conformity to masculine norms has been inversely related to help-seeking and positively correlated with concerning health variables, such as substance use. Nonetheless, past reliance on total scores has obscured the complexity of associations with the CMNI in that 30% of the findings in the present study reflected positive outcomes, particularly for health promotion. Subscales differed in their relationships with various outcomes: for one subscale they were predominantly positive, but six others were mostly negative. The situational and contextual implications of conformity to masculine norms and their relationships to positive and negative outcomes are discussed.

  14. 03-NIF Dedication: Norm Pattiz

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Norm Pattiz

    2009-07-02

    The National Ignition Facility, the world's largest laser system, was dedicated at a ceremony on May 29, 2009 at Lawrence Livermore National Laboratory. These are the remarks by Norm Pattiz, the chairman of Lawrence Livermore National Security, which manages Lawrence Livermore National Laboratory for the U.S. Department of Energy.

  15. 03-NIF Dedication: Norm Pattiz

    ScienceCinema

    Norm Pattiz

    2017-12-09

    The National Ignition Facility, the world's largest laser system, was dedicated at a ceremony on May 29, 2009 at Lawrence Livermore National Laboratory. These are the remarks by Norm Pattiz, the chairman of Lawrence Livermore National Security, which manages Lawrence Livermore National Laboratory for the U.S. Department of Energy.

  16. Multi-Shot Sensitivity-Encoded Diffusion Data Recovery Using Structured Low-Rank Matrix Completion (MUSSELS)

    PubMed Central

    Mani, Merry; Jacob, Mathews; Kelley, Douglas; Magnotta, Vincent

    2017-01-01

    Purpose To introduce a novel method for the recovery of multi-shot diffusion weighted (MS-DW) images from echo-planar imaging (EPI) acquisitions. Methods Current EPI-based MS-DW reconstruction methods rely on the explicit estimation of the motion-induced phase maps to recover artifact-free images. In the new formulation, the k-space data of the artifact-free DWI is recovered using a structured low-rank matrix completion scheme, which does not require explicit estimation of the phase maps. The structured matrix is obtained as the lifting of the multi-shot data. The smooth phase-modulations between shots manifest as null-space vectors of this matrix, which implies that the structured matrix is low-rank. The missing entries of the structured matrix are filled in using a nuclear-norm minimization algorithm subject to the data-consistency. The formulation enables the natural introduction of smoothness regularization, thus enabling implicit motion-compensated recovery of the MS-DW data. Results Our experiments on in-vivo data show effective removal of artifacts arising from inter-shot motion using the proposed method. The method is shown to achieve better reconstruction than the conventional phase-based methods. Conclusion We demonstrate the utility of the proposed method to effectively recover artifact-free images from Cartesian fully/under-sampled and partial Fourier acquired data without the use of explicit phase estimates. PMID:27550212

  17. Cultural variation in communal versus exchange norms: Implications for social support.

    PubMed

    Miller, Joan G; Akiyama, Hiroko; Kapadia, Shagufa

    2017-07-01

    Whereas an interdependent cultural view of self has been linked to communal norms and to socially supportive behavior, its relationship to social support has been called into question in research suggesting that discomfort in social support is associated with an interdependent cultural view of self (e.g., Taylor et al., 2004). These contrasting claims were addressed in 2 studies conducted among Japanese, Indian, and American adults. Assessing everyday social support, Study 1 showed that Japanese and Americans rely on exchange norms more frequently than Indians among friends, whereas American rely on exchange norms more frequently than Indians and Japanese among siblings. Assessing responses to vignettes, Study 2 demonstrated that Japanese and Americans rely more frequently on exchange norms than Indians, with greatest relational concerns and most negative outlooks on social support observed among Japanese, less among Americans, and least among Indians. Results further indicated that relational concerns mediated the link between exchange norms and negative social support outlooks. Supporting past claims that relational concerns explain cultural variation in discomfort in social support (e.g., Kim, Sherman, & Taylor, 2008), the findings underscore the need to take into account as well the role of exchange norms in explaining such discomfort. The findings also highlight the existence of culturally variable approaches to exchange and call into question claims that discomfort in social support can be explained in terms of the global concept of an interdependent cultural view of self. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. The male-taller norm: Lack of evidence from a developing country.

    PubMed

    Sohn, K

    2015-08-01

    In general, women prefer men taller than themselves; this is referred to as the male-taller norm. However, since women are shorter than men on average, it is difficult to determine whether the fact that married women are on average shorter than their husbands results from the norm or is a simple artifact generated by the shorter stature of women. This study addresses the question by comparing the rate of adherence to the male-taller norm between actual mating and hypothetical random mating. A total of 7954 actually married couples are drawn from the last follow-up of the Indonesian Family Life Survey, a nationally representative survey. Their heights were measured by trained nurses. About 10,000 individuals are randomly sampled from the actual couples and randomly matched. An alternative random mating of about 100,000 couples is also performed, taking into account an age difference of 5 years within a couple. The rate of adherence to the male-taller norm is 93.4% for actual couples and 88.8% for random couples. The difference between the two figures is statistically significant, but it is emphasized that it is very small. The alternative random mating produces a rate of 91.4%. The male-taller norm exists in Indonesia, but only in a statistical sense. The small difference suggests that the norm is mostly explained by the fact that women are shorter than men on average. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Shifting more than the goal posts: developing classroom norms of inquiry-based learning in mathematics

    NASA Astrophysics Data System (ADS)

    Makar, Katie; Fielding-Wells, Jill

    2018-03-01

    The 3-year study described in this paper aims to create new knowledge about inquiry norms in primary mathematics classrooms. Mathematical inquiry addresses complex problems that contain ambiguities, yet classroom environments often do not adopt norms that promote curiosity, risk-taking and negotiation needed to productively engage with complex problems. Little is known about how teachers and students initiate, develop and maintain norms of mathematical inquiry in primary classrooms. The research question guiding this study is, "How do classroom norms develop that facilitate student learning in primary classrooms which practice mathematical inquiry?" The project will (1) analyse a video archive of inquiry lessons to identify signature practices that enhance productive classroom norms of mathematical inquiry and facilitate learning, (2) engage expert inquiry teachers to collaborate to identify and design strategies for assisting teachers to develop and sustain norms over time that are conducive to mathematical inquiry and (3) support and study teachers new to mathematical inquiry adopting these practices in their classrooms. Anticipated outcomes include identification and illustration of classroom norms of mathematical inquiry, signature practices linked to these norms and case studies of primary teachers' progressive development of classroom norms of mathematical inquiry and how they facilitate learning.

  20. Longitudinal Relationships Among Perceived Injunctive and Descriptive Norms and Marijuana Use

    PubMed Central

    Napper, Lucy E.; Kenney, Shannon R.; Hummer, Justin F.; Fiorot, Sara; LaBrie, Joseph W.

    2016-01-01

    Objective: The current study uses longitudinal data to examine the relative influence of perceived descriptive and injunctive norms for proximal and distal referents on marijuana use. Method: Participants were 740 undergraduate students (67% female) who completed web-based surveys at two time points 12 months apart. Time 1 measures included reports of marijuana use, approval, perceived descriptive norms, and perceived injunctive norms for the typical student, close friends, and parents. At Time 2, students reported on their marijuana use. Results: Results of a path analysis suggest that, after we controlled for Time 1 marijuana use, greater perceived friend approval indirectly predicted Time 2 marijuana use as mediated by personal approval. Greater perceived parental approval was both indirectly and directly associated with greater marijuana use at follow-up. Perceived typical-student descriptive norms were neither directly nor indirectly related to Time 2 marijuana use. Conclusions: The findings support the role of proximal injunctive norms in predicting college student marijuana use up to 12 months later. The results indicate the potential importance of developing normative interventions that incorporate the social influences of proximal referents. PMID:27172578

  1. Conflicting contraceptive norms for men: equal responsibility versus women's bodily autonomy.

    PubMed

    James-Hawkins, Laurie; Dalessandro, Cristen; Sennott, Christie

    2018-05-15

    Most research investigating how men and women in heterosexual relationships negotiate contraceptive use focuses on the women's point of view. Using a sample of 44 interviews with men attending a western US university, this study examines norms governing men's participation in contraceptive use and pregnancy prevention and their responses to those norms. The paper demonstrates how competing norms around sexual health decision-making and women's bodily autonomy contribute to unintended outcomes that undermine young people's quest for egalitarian sexual relationships. While men largely agree that responsibility for sexual health decision-making should be shared with women, they also believe that women should have power over their own bodies and sexual health. However, the coexistence of these two competing norms - which call for both equal responsibility in decision-making and women's bodily autonomy - results in a disconnect between men saying that sexual health decision-making should be equal, but not always participating equally. Thus, men largely give contraceptive decision-making power over to women, putting the burden of pregnancy prevention onto women and letting men off the hook. It is concluded that men's negotiation of these competing norms reinforces unequal power and inequality in sexual relationships.

  2. The role of temporal context in norm-based encoding of faces.

    PubMed

    Van Rensbergen, Bram; Op de Beeck, Hans P

    2014-02-01

    Research shows that the human brain encodes faces in terms of how they relate to a prototypical face, a phenomenon referred to as norm-based encoding. The goal of this study was to examine the effect of short-term exposure on the development of the norm, independently of global, long-term exposure. We achieved this by varying the sequence of presentation of the stimuli while keeping global exposure constant. We found that a systematic manipulation of the average face in a set of 10 preceding trials can shift this norm toward that average. However, there was no effect of order or recency among these trials; thus, there was no evidence that the last faces mattered more than the first. This suggests that the position of the face norm is modified by information that is integrated across multiple recent faces.

  3. Criterion vs. Norm-referenced Testing.

    ERIC Educational Resources Information Center

    Pimsleur, Paul

    1975-01-01

    A norm-referenced evaluation system, which evaluates the student in comparison to his peers, is rejected in favor of a criterion-referenced system. The latter, which rates the performance of a student on an absolute standard, makes for an individualized approach. Two kinds of tests are distinguished, the formative, administered during the course…

  4. Football, Fast Cars, and Cheerleading: Adolescent Gender Norms, 1978-1989.

    ERIC Educational Resources Information Center

    Suitor, J. Jill; Rebel, Reavis

    1995-01-01

    Examines changes in adolescent gender norms in the 1980s, using data collected from 496 college students who graduated from high school between 1979 and 1982 or between 1988 and 1989. Findings indicate little change in gender norms across the decade. Boys continue to achieve prestige primarily through sports and school achievement, while girls…

  5. Performance of Dutch children on the Bayley III: a comparison study of US and Dutch norms.

    PubMed

    Steenis, Leonie J P; Verhoeven, Marjolein; Hessen, Dave J; van Baar, Anneloes L

    2015-01-01

    The Bayley Scales of Infant and Toddler Development-third edition (Bayley-III) are frequently used to assess early child development worldwide. However, the original standardization only included US children, and it is still unclear whether or not these norms are adequate for use in other populations. Recently, norms for the Dutch version of the Bayley-III (The Bayley-III-NL) were made. Scores based on Dutch and US norms were compared to study the need for population-specific norms. Scaled scores based on Dutch and US norms were compared for 1912 children between 14 days and 42 months 14 days. Next, the proportions of children scoring < 1-SD and < -2 SD based on the two norms were compared, to identify over- or under-referral for developmental delay resulting from non-population-based norms. Scaled scores based on Dutch norms fluctuated around values based on US norms on all subtests. The extent of the deviations differed across ages and subtests. Differences in means were significant across all five subtests (p < .01) with small to large effect sizes (ηp2) ranging from .03 to .26). Using the US instead of Dutch norms resulted in over-referral regarding gross motor skills, and under-referral regarding cognitive, receptive communication, expressive communication, and fine motor skills. The Dutch norms differ from the US norms for all subtests and these differences are clinically relevant. Population specific norms are needed to identify children with low scores for referral and intervention, and to facilitate international comparisons of population data.

  6. Collective learning for the emergence of social norms in networked multiagent systems.

    PubMed

    Yu, Chao; Zhang, Minjie; Ren, Fenghui

    2014-12-01

    Social norms such as social rules and conventions play a pivotal role in sustaining system order by regulating and controlling individual behaviors toward a global consensus in large-scale distributed systems. Systematic studies of efficient mechanisms that can facilitate the emergence of social norms enable us to build and design robust distributed systems, such as electronic institutions and norm-governed sensor networks. This paper studies the emergence of social norms via learning from repeated local interactions in networked multiagent systems. A collective learning framework, which imitates the opinion aggregation process in human decision making, is proposed to study the impact of agent local collective behaviors on the emergence of social norms in a number of different situations. In the framework, each agent interacts repeatedly with all of its neighbors. At each step, an agent first takes a best-response action toward each of its neighbors and then combines all of these actions into a final action using ensemble learning methods. Extensive experiments are carried out to evaluate the framework with respect to different network topologies, learning strategies, numbers of actions, influences of nonlearning agents, and so on. Experimental results reveal some significant insights into the manipulation and control of norm emergence in networked multiagent systems achieved through local collective behaviors.

  7. One-norm geometric quantum discord and critical point estimation in the XY spin chain

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheng, Chang-Cheng; Wang, Yao; Guo, Jin-Liang, E-mail: guojinliang80@163.com

    2016-11-15

    In contrast with entanglement and quantum discord (QD), we investigate the thermal quantum correlation in terms of Schatten one-norm geometric quantum discord (GQD) in the XY spin chain, and analyze their capabilities in detecting the critical point of quantum phase transition. We show that the one-norm GQD can reveal more properties about quantum correlation between two spins, especially for the long-range quantum correlation at finite temperature. Under the influences of site distance, anisotropy and temperature, one-norm GQD and its first derivative make it possible to detect the critical point efficiently for a general XY spin chain. - Highlights: • Comparingmore » with entanglement and QD, one-norm GQD is more robust versus the temperature. • One-norm GQD is more efficient in characterization of long-range quantum correlation between two distant qubits. • One-norm GQD performs well in highlighting the critical point of QPT at zero or low finite temperature. • One-norm GQD has a number of advantages over QD in detecting the critical point of the spin chain.« less

  8. Evolving Norms at the Intersection of Health and Trade

    PubMed Central

    Drope, Jeffrey; Lencucha, Raphael

    2014-01-01

    There has been growing tension at the intersection of health and economic policymaking as global governance has increased across sectors. This tension has been particularly evident between tobacco control and trade policy, as the international norms that frame them – particularly the Framework Convention on Tobacco Control and the World Trade Organization (WTO) – have continued to institutionalize. Using five case studies of major tobacco-related trade disputes from the principal multilateral system of trade governance – the WTO/General Agreement on Tariffs and Trade – we trace the evolution of these interacting norms over nearly 25 years. Our analytic framework particularly focuses on the actors that advance, defend and challenge these norms. We find that an increasingly broad network, which includes governments, intergovernmental organizations, non-governmental organizations and members of the epistemic community, is playing a more active role in seeking to resolve these tensions. Moreover, key economic actors are beginning to incorporate health more actively in their messaging and activities. We also demonstrate that the most recent resonant messages reflect a more nuanced integration of the two norms. The tobacco control example has direct relevance to related policy areas, including environment, safety, access to medicines, diet, and alcohol. PMID:24603086

  9. Evolving norms at the intersection of health and trade.

    PubMed

    Drope, Jeffrey; Lencucha, Raphael

    2014-06-01

    There has been growing tension at the intersection of health and economic policy making as global governance has increased across sectors. This tension has been particularly evident between tobacco control and trade policy, as the international norms that frame them -- particularly the Framework Convention on Tobacco Control and the World Trade Organization (WTO) -- have continued to institutionalize. Using five case studies of major tobacco-related trade disputes from the principal multilateral system of trade governance -- the WTO/General Agreement on Tariffs and Trade -- we trace the evolution of these interacting norms over nearly twenty-five years. Our analytic framework focuses on the actors that advance, defend, and challenge these norms. We find that an increasingly broad network, which includes governments, intergovernmental organizations, nongovernmental organizations, and members of the epistemic community, is playing a more active role in seeking to resolve these tensions. Moreover, key economic actors are beginning to incorporate health more actively into their messaging and activities. We also demonstrate that the most recent resonant messages reflect a more nuanced integration of the two norms. The tobacco control example has direct relevance to related policy areas, including environment, safety, access to medicines, diet, and alcohol. Copyright © 2014 by Duke University Press.

  10. Metric freeness and projectivity for classical and quantum normed modules

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Helemskii, A Ya

    2013-07-31

    In functional analysis, there are several diverse approaches to the notion of projective module. We show that a certain general categorical scheme contains all basic versions as special cases. In this scheme, the notion of free object comes to the foreground, and, in the best categories, projective objects are precisely retracts of free ones. We are especially interested in the so-called metric version of projectivity and characterize the metrically free classical and quantum (= operator) normed modules. Informally speaking, so-called extremal projectivity, which was known earlier, is interpreted as a kind of 'asymptotical metric projectivity'. In addition, we answer themore » following specific question in the geometry of normed spaces: what is the structure of metrically projective modules in the simplest case of normed spaces? We prove that metrically projective normed spaces are precisely the subspaces of l{sub 1}(M) (where M is a set) that are denoted by l{sub 1}{sup 0}(M) and consist of finitely supported functions. Thus, in this case, projectivity coincides with freeness. Bibliography: 28 titles.« less

  11. Predicting having condoms available among adolescents: the role of personal norm and enjoyment.

    PubMed

    Jellema, Ilke J; Abraham, Charles; Schaalma, Herman P; Gebhardt, Winifred A; van Empelen, Pepijn

    2013-05-01

    Having condoms available has been shown to be an important predictor of condom use. We examined whether or not personal norm and goal enjoyment contribute to predicting having condoms available in the context of cognition specified by the theory of planned behaviour (TPB). Prospective survey study, with a baseline and follow-up measurement (at 3 months). Data were gathered using an online survey. In total 282 adolescents (mean age = 15.6, 74% female adolescents) completed both questionnaires. At baseline, demographics, sexual experience, condom use, TPB variables, descriptive norm, personal norm, and enjoyment towards having condoms available were measured. At T2 (3 months later) having condoms available was measured. Direct and moderating effects of personal norm and goal enjoyment were examined by means of hierarchical linear regression analyses. Regression analyses yielded a direct effect of self-efficacy and personal norm on condom availability. In addition, moderation of the intention-behaviour relation by goal enjoyment added to the variance explained. The final model explained approximately 35% of the variance in condom availability. Personal norm and goal enjoyment add to the predictive utility of a TPB model of having condoms available and may be useful intervention targets. What is already known about this subject? Having condoms available is an important prerequisite for actual condom use. The theory of planned behaviour has successfully been applied to explain condom availability behaviour. The theory of planned behaviour has been criticized for not adequately taking into account affective motivation. What does this study add? Personal norm and goal enjoyment add to the predictive utility of the model. Personal norm explains condom availability directly, enjoyment increases intention enactment. Personal norm and goal enjoyment therefore are useful intervention targets. © 2012 The British Psychological Society.

  12. Evaluation of RxNorm for Medication Clinical Decision Support.

    PubMed

    Freimuth, Robert R; Wix, Kelly; Zhu, Qian; Siska, Mark; Chute, Christopher G

    2014-01-01

    We evaluated the potential use of RxNorm to provide standardized representations of generic drug name and route of administration to facilitate management of drug lists for clinical decision support (CDS) rules. We found a clear representation of generic drug name but not route of administration. We identified several issues related to data quality, including erroneous or missing defined relationships, and the use of different concept hierarchies to represent the same drug. More importantly, we found extensive semantic precoordination of orthogonal concepts related to route and dose form, which would complicate the use of RxNorm for drug-based CDS. This study demonstrated that while RxNorm is a valuable resource for the standardization of medications used in clinical practice, additional work is required to enhance the terminology so that it can support expanded use cases, such as managing drug lists for CDS.

  13. 3-D Magnetotelluric Forward Modeling And Inversion Incorporating Topography By Using Vector Finite-Element Method Combined With Divergence Corrections Based On The Magnetic Field (VFEH++)

    NASA Astrophysics Data System (ADS)

    Shi, X.; Utada, H.; Jiaying, W.

    2009-12-01

    The vector finite-element method combined with divergence corrections based on the magnetic field H, referred to as VFEH++ method, is developed to simulate the magnetotelluric (MT) responses of 3-D conductivity models. The advantages of the new VFEH++ method are the use of edge-elements to eliminate the vector parasites and the divergence corrections to explicitly guarantee the divergence-free conditions in the whole modeling domain. 3-D MT topographic responses are modeling using the new VFEH++ method, and are compared with those calculated by other numerical methods. The results show that MT responses can be modeled highly accurate using the VFEH+ +method. The VFEH++ algorithm is also employed for the 3-D MT data inversion incorporating topography. The 3-D MT inverse problem is formulated as a minimization problem of the regularized misfit function. In order to avoid the huge memory requirement and very long time for computing the Jacobian sensitivity matrix for Gauss-Newton method, we employ the conjugate gradient (CG) approach to solve the inversion equation. In each iteration of CG algorithm, the cost computation is the product of the Jacobian sensitivity matrix with a model vector x or its transpose with a data vector y, which can be transformed into two pseudo-forwarding modeling. This avoids the full explicitly Jacobian matrix calculation and storage which leads to considerable savings in the memory required by the inversion program in PC computer. The performance of CG algorithm will be illustrated by several typical 3-D models with horizontal earth surface and topographic surfaces. The results show that the VFEH++ and CG algorithms can be effectively employed to 3-D MT field data inversion.

  14. Solving coupled groundwater flow systems using a Jacobian Free Newton Krylov method

    NASA Astrophysics Data System (ADS)

    Mehl, S.

    2012-12-01

    Jacobian Free Newton Kyrlov (JFNK) methods can have several advantages for simulating coupled groundwater flow processes versus conventional methods. Conventional methods are defined here as those based on an iterative coupling (rather than a direct coupling) and/or that use Picard iteration rather than Newton iteration. In an iterative coupling, the systems are solved separately, coupling information is updated and exchanged between the systems, and the systems are re-solved, etc., until convergence is achieved. Trusted simulators, such as Modflow, are based on these conventional methods of coupling and work well in many cases. An advantage of the JFNK method is that it only requires calculation of the residual vector of the system of equations and thus can make use of existing simulators regardless of how the equations are formulated. This opens the possibility of coupling different process models via augmentation of a residual vector by each separate process, which often requires substantially fewer changes to the existing source code than if the processes were directly coupled. However, appropriate perturbation sizes need to be determined for accurate approximations of the Frechet derivative, which is not always straightforward. Furthermore, preconditioning is necessary for reasonable convergence of the linear solution required at each Kyrlov iteration. Existing preconditioners can be used and applied separately to each process which maximizes use of existing code and robust preconditioners. In this work, iteratively coupled parent-child local grid refinement models of groundwater flow and groundwater flow models with nonlinear exchanges to streams are used to demonstrate the utility of the JFNK approach for Modflow models. Use of incomplete Cholesky preconditioners with various levels of fill are examined on a suite of nonlinear and linear models to analyze the effect of the preconditioner. Comparisons of convergence and computer simulation time are made using

  15. Characterizing L1-norm best-fit subspaces

    NASA Astrophysics Data System (ADS)

    Brooks, J. Paul; Dulá, José H.

    2017-05-01

    Fitting affine objects to data is the basis of many tools and methodologies in statistics, machine learning, and signal processing. The L1 norm is often employed to produce subspaces exhibiting a robustness to outliers and faulty observations. The L1-norm best-fit subspace problem is directly formulated as a nonlinear, nonconvex, and nondifferentiable optimization problem. The case when the subspace is a hyperplane can be solved to global optimality efficiently by solving a series of linear programs. The problem of finding the best-fit line has recently been shown to be NP-hard. We present necessary conditions for optimality for the best-fit subspace problem, and use them to characterize properties of optimal solutions.

  16. Four Year-Olds Use Norm-Based Coding for Face Identity

    ERIC Educational Resources Information Center

    Jeffery, Linda; Read, Ainsley; Rhodes, Gillian

    2013-01-01

    Norm-based coding, in which faces are coded as deviations from an average face, is an efficient way of coding visual patterns that share a common structure and must be distinguished by subtle variations that define individuals. Adults and school-aged children use norm-based coding for face identity but it is not yet known if pre-school aged…

  17. Current approaches to norms research

    Treesearch

    John L. Heywood

    2000-01-01

    The dialogue session was a continuation of a debate about norms and the application of normative standards to wilderness management that has taken place throughout the 1990s at national meetings and in the research literature. Researchers who have made significant contributions to the normative approach to wilderness recreation management presented three approaches to...

  18. Sparsistency and Rates of Convergence in Large Covariance Matrix Estimation.

    PubMed

    Lam, Clifford; Fan, Jianqing

    2009-01-01

    This paper studies the sparsistency and rates of convergence for estimating sparse covariance and precision matrices based on penalized likelihood with nonconvex penalty functions. Here, sparsistency refers to the property that all parameters that are zero are actually estimated as zero with probability tending to one. Depending on the case of applications, sparsity priori may occur on the covariance matrix, its inverse or its Cholesky decomposition. We study these three sparsity exploration problems under a unified framework with a general penalty function. We show that the rates of convergence for these problems under the Frobenius norm are of order (s(n) log p(n)/n)(1/2), where s(n) is the number of nonzero elements, p(n) is the size of the covariance matrix and n is the sample size. This explicitly spells out the contribution of high-dimensionality is merely of a logarithmic factor. The conditions on the rate with which the tuning parameter λ(n) goes to 0 have been made explicit and compared under different penalties. As a result, for the L(1)-penalty, to guarantee the sparsistency and optimal rate of convergence, the number of nonzero elements should be small: sn'=O(pn) at most, among O(pn2) parameters, for estimating sparse covariance or correlation matrix, sparse precision or inverse correlation matrix or sparse Cholesky factor, where sn' is the number of the nonzero elements on the off-diagonal entries. On the other hand, using the SCAD or hard-thresholding penalty functions, there is no such a restriction.

  19. Social support and social norms: do both contribute to predicting leisure-time exercise?

    PubMed

    Okun, Morris A; Ruehlman, Linda; Karoly, Paul; Lutz, Rafer; Fairholme, Chris; Schaub, Rachel

    2003-01-01

    To clarify the contribution of social support and social norms to exercise behavior. A sample of 363 college students completed a questionnaire that assessed social support and social negativity from friends, descriptive and injunctive social norms related to friends, perceived behavioral control, attitude, intention, and leisure-time exercise. Esteem social support was the strongest predictor of total and strenuous leisure-time exercise (P < .001), and descriptive norm was a significant (P < .01 predictor of strenuous leisure-time exercise. Social support and social norms contribute independently to our understanding of variation in the frequency of strenuous leisure-time exercise.

  20. Norm overlap between many-body states: Uncorrelated overlap between arbitrary Bogoliubov product states

    NASA Astrophysics Data System (ADS)

    Bally, B.; Duguet, T.

    2018-02-01

    Background: State-of-the-art multi-reference energy density functional calculations require the computation of norm overlaps between different Bogoliubov quasiparticle many-body states. It is only recently that the efficient and unambiguous calculation of such norm kernels has become available under the form of Pfaffians [L. M. Robledo, Phys. Rev. C 79, 021302 (2009), 10.1103/PhysRevC.79.021302]. Recently developed particle-number-restored Bogoliubov coupled-cluster (PNR-BCC) and particle-number-restored Bogoliubov many-body perturbation (PNR-BMBPT) ab initio theories [T. Duguet and A. Signoracci, J. Phys. G 44, 015103 (2017), 10.1088/0954-3899/44/1/015103] make use of generalized norm kernels incorporating explicit many-body correlations. In PNR-BCC and PNR-BMBPT, the Bogoliubov states involved in the norm kernels differ specifically via a global gauge rotation. Purpose: The goal of this work is threefold. We wish (i) to propose and implement an alternative to the Pfaffian method to compute unambiguously the norm overlap between arbitrary Bogoliubov quasiparticle states, (ii) to extend the first point to explicitly correlated norm kernels, and (iii) to scrutinize the analytical content of the correlated norm kernels employed in PNR-BMBPT. Point (i) constitutes the purpose of the present paper while points (ii) and (iii) are addressed in a forthcoming paper. Methods: We generalize the method used in another work [T. Duguet and A. Signoracci, J. Phys. G 44, 015103 (2017), 10.1088/0954-3899/44/1/015103] in such a way that it is applicable to kernels involving arbitrary pairs of Bogoliubov states. The formalism is presently explicated in detail in the case of the uncorrelated overlap between arbitrary Bogoliubov states. The power of the method is numerically illustrated and benchmarked against known results on the basis of toy models of increasing complexity. Results: The norm overlap between arbitrary Bogoliubov product states is obtained under a closed

  1. Misperception of Peer Weight Norms and Its Association with Overweight and Underweight Status among Adolescents

    PubMed Central

    Perkins, Jessica M.; Perkins, H. W.; Craig, David W.

    2014-01-01

    Previous research has revealed pervasive misperceptions of peer norms for a variety of behaviors among adolescents such as alcohol use, smoking, and bullying, and that these misperceptions are predictors of personal behavior. Similarly, misperception of peer weight norms may be a pervasive and important risk factor for adolescent weight status. Thus, the comparative association of actual and perceived peer weight norms is examined in relation to personal weight status. Secondary school students in 40 middle and high schools (n=40,328) were surveyed about their perceptions of the peer weight norm for same gender and grade within their school. Perceived norms were compared to aggregate self-reports of weight for these same groups. Overestimation of peer weight norms by more than 5% occurred among 26% of males and 20% of females (by 22 and 16 pounds on average, respectively). Underestimation occurred among 38% of males as well as females (by 16 and 13 pounds on average, respectively). Personal overweight status based on body mass index (BMI) was much more prevalent among respondents who overestimated peer weight norms as was personal underweight status among respondents who underestimated norms. Perception of the peer norm was the strongest predictor of personal BMI among all personal and school variables examined for both male and female students. Thus, reducing misperceived weight norms should be given more attention as a potential avenue for preventing obesity and eating disorders. PMID:24488532

  2. Masculine Norms, Avoidant Coping, Asian Values and Depression among Asian American Men

    PubMed Central

    Iwamoto, Derek Kenji; Liao, Liang; Liu, William Ming

    2010-01-01

    Contrary to the “model minority” myth, growing research indicates that the rates of mental health problems among Asian Americans may be higher than initially assumed. This study seeks to add to the scant knowledge regarding the mental health of Asian American men by examining the role of masculine norms, coping and cultural values in predicting depression among this population (N=149). Results reveal that Asian American men who used avoidant coping strategies and endorsed the masculine norm Dominance reported higher levels of depressive symptoms. In contrast, endorsing Winning masculine norms was associated to lower levels of depressive symptoms. Findings suggest that adherence to masculine norms and avoidant coping strategies play a salient role in the mental health of Asian American men. PMID:20657794

  3. Norms About Nonmarital Pregnancy and Willingness to Provide Resources to Unwed Parents

    PubMed Central

    Mollborn, Stefanie

    2009-01-01

    Contested social norms underlie public concern about adults’ and teenagers’ nonmarital pregnancy. The original, vignette-based National Pregnancy Norms Survey (N = 812) measures these norms and related sanctions. Descriptive analyses report embarrassment at the prospect of a nonmarital pregnancy by age and gender of hypothetical prospective parents and age, race or ethnicity, and socioeconomic status of respondents. Multivariate analyses show that embarrassment about nonmarital pregnancy is frequently weak but much stronger when prospective parents are teenagers. Embarrassment predicts respondents’ hypothetical sanctions of a new parent in their family by withholding several types of needed material resources. Because research has shown that such resources affect education and income, this study helps explain how violating norms might lead to negative outcomes among unmarried parents. PMID:21691443

  4. Masculine Norms, Avoidant Coping, Asian Values and Depression among Asian American Men.

    PubMed

    Iwamoto, Derek Kenji; Liao, Liang; Liu, William Ming

    2010-01-01

    Contrary to the "model minority" myth, growing research indicates that the rates of mental health problems among Asian Americans may be higher than initially assumed. This study seeks to add to the scant knowledge regarding the mental health of Asian American men by examining the role of masculine norms, coping and cultural values in predicting depression among this population (N=149). Results reveal that Asian American men who used avoidant coping strategies and endorsed the masculine norm Dominance reported higher levels of depressive symptoms. In contrast, endorsing Winning masculine norms was associated to lower levels of depressive symptoms. Findings suggest that adherence to masculine norms and avoidant coping strategies play a salient role in the mental health of Asian American men.

  5. Using Facebook to deliver a social norm intervention to reduce problem drinking at university.

    PubMed

    Ridout, Brad; Campbell, Andrew

    2014-11-01

    University students usually overestimate peer alcohol use, resulting in them 'drinking up' to perceived norms. Social norms theory suggests correcting these inflated perceptions can reduce alcohol consumption. Recent findings by the current authors show portraying oneself as 'a drinker' is considered by many students to be a socially desirable component of their Facebook identity, perpetuating an online culture that normalises binge drinking. However, social networking sites have yet to be utilised in social norms interventions. Actual and perceived descriptive and injunctive drinking norms were collected from 244 university students. Ninety-five students screened positive for hazardous drinking and were randomly allocated to a control group or intervention group that received social norms feedback via personalised Facebook private messages over three sessions. At 1 month post-intervention, the quantity and frequency of alcohol consumed by intervention group during the previous month had significantly reduced compared with baseline and controls. Reductions were maintained 3 months post-intervention. Intervention group perceived drinking norms were significantly more accurate post-intervention. This is the first study to test the feasibility of using Facebook to deliver social norms interventions. Correcting misperceptions of peer drinking norms resulted in clinically significant reductions in alcohol use. Facebook has many advantages over traditional social norms delivery, providing an innovative method for tackling problem drinking at university. These results have implications for the use of Facebook to deliver positive messages about safe alcohol use to students, which may counter the negative messages regarding alcohol normally seen on Facebook. © 2014 Australasian Professional Society on Alcohol and other Drugs.

  6. Discourse norms as default rules: structuring corporate speech to multiple stakeholders.

    PubMed

    Yosifon, David G

    2011-01-01

    This Article analyzes corporate speech problems through the framework of corporate law. The focus here is on the "discourse norms" that regulate corporate speech to various corporate stakeholders, including shareholders, workers, and consumers. I argue that these "discourse norms" should be understood as default terms in the "nexus-of-contracts" that comprises the corporation. Having reviewed the failure of corporate law as it bears on the interests of non-shareholding stakeholders such as workers and consumers, I urge the adoption of prescriptive discourse norms as an approach to reforming corporate governance in a socially useful manner.

  7. Subjective Norms Predicting Computer Use.

    ERIC Educational Resources Information Center

    Marcinkiewicz, Henryk R.

    This study was part of a series of studies examining the relationship of teacher variables to teachers' adoption of computer use. Previous studies have considered computer use as a process of the adoption of innovation and as a result of the influence of the internal variables of the person. This study adds the variable of subjective norms because…

  8. Evaluation of RxNorm for Medication Clinical Decision Support

    PubMed Central

    Freimuth, Robert R.; Wix, Kelly; Zhu, Qian; Siska, Mark; Chute, Christopher G.

    2014-01-01

    We evaluated the potential use of RxNorm to provide standardized representations of generic drug name and route of administration to facilitate management of drug lists for clinical decision support (CDS) rules. We found a clear representation of generic drug name but not route of administration. We identified several issues related to data quality, including erroneous or missing defined relationships, and the use of different concept hierarchies to represent the same drug. More importantly, we found extensive semantic precoordination of orthogonal concepts related to route and dose form, which would complicate the use of RxNorm for drug-based CDS. This study demonstrated that while RxNorm is a valuable resource for the standardization of medications used in clinical practice, additional work is required to enhance the terminology so that it can support expanded use cases, such as managing drug lists for CDS. PMID:25954360

  9. The bank of standardized stimuli (BOSS): comparison between French and English norms.

    PubMed

    Brodeur, Mathieu B; Kehayia, Eva; Dion-Lessard, Geneviève; Chauret, Mélissa; Montreuil, Tina; Dionne-Dostie, Emmanuelle; Lepage, Martin

    2012-12-01

    Throughout the last decades, numerous picture data sets have been developed, such as the Snodgrass and Vanderwart (1980) set, and have been normalized for variables such as name and familiarity; however, due to cultural and linguistic differences, norms can vary from one country to another. The effect due specifically to culture has already been demonstrated by comparing samples from different countries where the same language is spoken. On the other hand, it is still not clear how differences between languages may affect norms. The present study explores this issue by collecting and comparing norms on names and many other features from French Canadian speakers and English Canadian speakers living in Montreal, who thus live in similar cultural environments. Norms were collected for the photos of objects from the Bank of Standardized Stimuli (BOSS) by asking participants to name the objects, to categorize them, and to rate their familiarity, visual complexity, object agreement, viewpoint agreement, and manipulability. Names and ratings from the French speakers are available in Appendix A, available in the supplemental materials. The results show that most of the norms are comparable across linguistic groups and also that the ratings given are correlated across linguistic groups. The only significant group differences were found in viewpoint agreement and visual complexity. Overall, there was good concordance between the norms collected from French and English native speakers living in the same cultural setting.

  10. Asymptotic state discrimination and a strict hierarchy in distinguishability norms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chitambar, Eric; Hsieh, Min-Hsiu

    2014-11-15

    In this paper, we consider the problem of discriminating quantum states by local operations and classical communication (LOCC) when an arbitrarily small amount of error is permitted. This paradigm is known as asymptotic state discrimination, and we derive necessary conditions for when two multipartite states of any size can be discriminated perfectly by asymptotic LOCC. We use this new criterion to prove a gap in the LOCC and separable distinguishability norms. We then turn to the operational advantage of using two-way classical communication over one-way communication in LOCC processing. With a simple two-qubit product state ensemble, we demonstrate a strictmore » majorization of the two-way LOCC norm over the one-way norm.« less

  11. Discourses with potential to disrupt traditional nursing education: Nursing teachers' talk about norm-critical competence.

    PubMed

    Tengelin, Ellinor; Dahlborg-Lyckhage, Elisabeth

    2017-01-01

    This paper describes the discourses underlying nursing teachers' talk about their own norm-critical competence. Norm criticism is an approach that promotes awareness and criticism of the norms and power structures that exert an excluding effect in society in general and in the healthcare encounter in particular. Given the unequal relationships that can exist in healthcare, for example relationships shaped by racism, sexism and classism, a norm-critical approach to nursing education would help illuminate these matters. The studied empirical material consisted of focus group interviews. Nursing teachers discussed their norm-critical competence based on the university course "Norm-Aware Caring" in which they had recently participated. Through a critical discourse analysis, three discourses were identified in their talk, all of which had the potential to disrupt traditional, normative nursing education. However, in all three discourses there was an underlying discourse of normality, clearly positioning the teachers as exemplifying the "normal." The binary constructed between normality and otherness contradicts a basic tenet of the norm-critical approach and may hamper the development of genuine norm-critical competence in nursing education. © 2016 John Wiley & Sons Ltd.

  12. Alcohol Use Disorders and Perceived Drinking Norms: Ethnic Differences in Israeli Adults

    PubMed Central

    Shmulewitz, Dvora; Wall, Melanie M.; Keyes, Katherine M.; Aharonovich, Efrat; Aivadyan, Christina; Greenstein, Eliana; Spivak, Baruch; Weizman, Abraham; Frisch, Amos; Hasin, Deborah

    2012-01-01

    Objective: Individuals’ perceptions of drinking acceptability in their society (perceived injunctive drinking norms) are widely assumed to explain ethnic group differences in drinking and alcohol use disorders (AUDs), but this has never been formally tested. Immigrants to Israel from the former Soviet Union (FSU) are more likely to drink and report AUD symptoms than other Israelis. We tested perceived drinking norms as a mediator of differences between FSU immigrants and other Israelis in drinking and AUDs. Method: Adult household residents (N = 1,349) selected from the Israeli population register were assessed with a structured interview measuring drinking, AUD symptoms, and perceived drinking norms. Regression analyses were used to produce odds ratios (OR) and risk ratios (RR) and 95% confidence intervals (CI) to test differences between FSU immigrants and other Israelis on binary and graded outcomes. Mediation of FSU effects by perceived drinking norms was tested with bootstrapping procedures. Results: FSU immigrants were more likely than other Israelis to be current drinkers (OR = 2.39, CI [1.61, 3.55]), have higher maximum number of drinks per day (RR = 1.88, CI [1.64, 2.16]), have any AUD (OR = 1.75, CI [1.16, 2.64]), score higher on a continuous measure of AUD (RR = 1.44, CI [1.12, 1.84]), and perceive more permissive drinking norms (p < .0001). For all four drinking variables, the FSU group effect was at least partially mediated by perceived drinking norms. Conclusions: This is the first demonstration that drinking norms mediate ethnic differences in AUDs. This work contributes to understanding ethnic group differences in drinking and AUDs, potentially informing etiologic research and public policy aimed at reducing alcohol-related harm. PMID:23036217

  13. The Role of Indian Caste Identity and Caste Inconsistent Norms on Status Representation.

    PubMed

    Sankaran, Sindhuja; Sekerdej, Maciek; von Hecker, Ulrich

    2017-01-01

    The Indian caste system is a complex social structure wherein social roles like one's profession became 'hereditary,' resulting in restricted social mobility and fixed status hierarchies. Furthermore, we argue that the inherent property of caste heightens group identification with one's caste. Highly identified group members would protect the identity of the group in situations when group norms are violated. In this paper, we were interested in examining the consequence of caste norm violation and how an individual's status is mentally represented. High caste norms are associated with moral values while the lower caste norms are associated with immorality. We predicted a 'black sheep effect,' that is, when high caste individuals' group identity (caste norm violation condition) is threatened their salient high caste identity would increase, thereby resulting in devaluing the status of their fellow in-group member if the latter is perceived as perpetrator. We presented participants with a social conflict situation of a victim and a perpetrator that is ' Caste norm consistent' (Lower caste individual as a perpetrator and higher caste individual as a victim) and vice versa 'Caste norm inconsistent' condition (higher caste individual as perpetrator and lower caste individual as a victim). Then, participants had to choose from nine pictorial depictions representing the protagonists in the story on a vertical line, with varying degrees of status distance. Results showed evidence for the black sheep effect and, furthermore, revealed that no other identity (religious, national, and regional) resulted in devaluing the status of fellow in-group member. These results help us understand the 'black sheep' effect in the context of moral norms and status representation and are discussed in the framework of the Indian society.

  14. Athletic identity, descriptive norms, and drinking among athletes transitioning to college

    PubMed Central

    Grossbard, Joel R.; Geisner, Irene M.; Mastroleo, Nadine R.; Kilmer, Jason R.; Turrisi, Rob; Larimer, Mary E.

    2010-01-01

    College student–athletes are at risk for heavy alcohol consumption and related consequences. The present study evaluated the influence of college student and college athlete descriptive norms and levels of athletic identity on drinking and related consequences among incoming college students attending two universities (N = 1119). Prior to the beginning of their first year of college, students indicating high school athletic participation completed assessments of athletic identity, alcohol consumption, drinking-related consequences, and normative perceptions of alcohol use. Estimations of drinking by college students and student–athletes were significantly greater than self-reported drinking. Athletic identity moderated associations among gender, perceived norms, drinking, and related consequences. Athlete-specific norms had a stronger effect on drinking among those reporting higher levels of athletic identity, and higher levels of athletic identity exclusively protected males from experiencing drinking-related consequences. Implications of the role of athletic identity in the development of social norms interventions targeted at high school athletes transitioning to college are discussed. PMID:19095359

  15. Meta-analyses of the relationship between conformity to masculine norms and mental health-related outcomes.

    PubMed

    Wong, Y Joel; Ho, Moon-Ho Ringo; Wang, Shu-Yi; Miller, I S Keino

    2017-01-01

    Despite theoretical postulations that individuals' conformity to masculine norms is differentially related to mental health-related outcomes depending on a variety of contexts, there has not been any systematic synthesis of the empirical research on this topic. Therefore, the authors of this study conducted meta-analyses of the relationships between conformity to masculine norms (as measured by the Conformity to Masculine Norms Inventory-94 and other versions of this scale) and mental health-related outcomes using 78 samples and 19,453 participants. Conformity to masculine norms was modestly and unfavorably associated with mental health as well as moderately and unfavorably related to psychological help seeking. The authors also identified several moderation effects. Conformity to masculine norms was more strongly correlated with negative social functioning than with psychological indicators of negative mental health. Conformity to the specific masculine norms of self-reliance, power over women, and playboy were unfavorably, robustly, and consistently related to mental health-related outcomes, whereas conformity to the masculine norm of primacy of work was not significantly related to any mental health-related outcome. These findings highlight the need for researchers to disaggregate the generic construct of conformity to masculine norms and to focus instead on specific dimensions of masculine norms and their differential associations with other outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Why is it Bad to Make a Mess? Preschoolers' Conceptions of Pragmatic Norms.

    PubMed

    Dahl, Audun; Kim, Lizbeth

    2014-01-01

    A common type of transgression in early childhood involves creating inconvenience, for instance by spilling, playing with breakable objects, or otherwise interfering with people's ongoing activities. Despite the prevalence of such pragmatic transgressions, little is known about children's conceptions of norms prohibiting these acts. The present study investigated whether 3-to 5-year-olds ( N = 58) see pragmatic norms as distinct from first-order moral (welfare and rights of others), prudential (welfare of agent), and social conventional norms. Children judged all four types of transgressions to be wrong. Justifications for pragmatic transgressions focused on inconvenience to the transgressor, inconvenience to others, or material disorder. Children rated pragmatic and conventional transgressions as less serious than moral and prudential transgressions. Latent Class Analysis provided further support for the conclusion that preschoolers see pragmatic norms as a category distinct from first-order moral, prudential, and social conventional norms.

  17. Cannabis Use Behaviors and Social Anxiety: The Roles of Perceived Descriptive and Injunctive Social Norms

    PubMed Central

    Ecker, Anthony H.; Buckner, Julia D.

    2014-01-01

    Objective: Individuals with greater social anxiety are particularly vulnerable to cannabis-related impairment. Descriptive norms (beliefs about others’ use) and injunctive norms (beliefs regarding others’ approval of risky use) may be particularly relevant to cannabis-related behaviors among socially anxious persons if they use cannabis for fear of evaluation for deviating from what they believe to be normative behaviors. Yet, little research has examined the impact of these social norms on the relationships between social anxiety and cannabis use behaviors. Method: The current study investigated whether the relationships of social anxiety to cannabis use and use-related problems varied as a function of social norms. The sample comprised 230 (63.0% female) current cannabis-using undergraduates. Results: Injunctive norms (regarding parents, not friends) moderated the relationship between social anxiety and cannabis-related problem severity. Post hoc probing indicated that among participants with higher (but not lower) social anxiety, those with greater norm endorsement reported the most severe impairment. Injunctive norms (parents) also moderated the relationship between social anxiety and cannabis use frequency such that those with higher social anxiety and lower norm endorsement used cannabis less frequently. Descriptive norms did not moderate the relationship between social anxiety and cannabis use frequency. Conclusions: Socially anxious cannabis users appear to be especially influenced by beliefs regarding parents’ approval of risky cannabis use. Results underscore the importance of considering reference groups and the specific types of norms in understanding factors related to cannabis use behaviors among this vulnerable population. PMID:24411799

  18. Differential effects of exposure to social norms campaigns: a cause for concern.

    PubMed

    Campo, Shelly; Cameron, Kenzie A

    2006-01-01

    College students' processing of alcohol social norms messages, related effects on normative judgments, attitudes toward their own behaviors, and perception of undergraduate attitudes were examined using expectancy violation theories and social norms marketing. Data were collected from 2 universities (N = 393). Following message exposure, the majority moved their normative judgments toward the statistic provided in the message. Slight attitude change occurred but not always in the desired direction. Those most likely to develop unhealthier attitudes drank more than those who developed healthier attitudes, consistent with psychological reactance to the messages. Therefore, the effects of social norms campaigns on those at greatest risk for primary and secondary alcohol effects due to their increased alcohol consumption could lead to increased risk for those participants, indicating that the widespread use of social norms campaigns needs to be scrutinized.

  19. Toric Networks, Geometric R-Matrices and Generalized Discrete Toda Lattices

    NASA Astrophysics Data System (ADS)

    Inoue, Rei; Lam, Thomas; Pylyavskyy, Pavlo

    2016-11-01

    We use the combinatorics of toric networks and the double affine geometric R-matrix to define a three-parameter family of generalizations of the discrete Toda lattice. We construct the integrals of motion and a spectral map for this system. The family of commuting time evolutions arising from the action of the R-matrix is explicitly linearized on the Jacobian of the spectral curve. The solution to the initial value problem is constructed using Riemann theta functions.

  20. Posterior propriety for hierarchical models with log-likelihoods that have norm bounds

    DOE PAGES

    Michalak, Sarah E.; Morris, Carl N.

    2015-07-17

    Statisticians often use improper priors to express ignorance or to provide good frequency properties, requiring that posterior propriety be verified. Our paper addresses generalized linear mixed models, GLMMs, when Level I parameters have Normal distributions, with many commonly-used hyperpriors. It provides easy-to-verify sufficient posterior propriety conditions based on dimensions, matrix ranks, and exponentiated norm bounds, ENBs, for the Level I likelihood. Since many familiar likelihoods have ENBs, which is often verifiable via log-concavity and MLE finiteness, our novel use of ENBs permits unification of posterior propriety results and posterior MGF/moment results for many useful Level I distributions, including those commonlymore » used with multilevel generalized linear models, e.g., GLMMs and hierarchical generalized linear models, HGLMs. Furthermore, those who need to verify existence of posterior distributions or of posterior MGFs/moments for a multilevel generalized linear model given a proper or improper multivariate F prior as in Section 1 should find the required results in Sections 1 and 2 and Theorem 3 (GLMMs), Theorem 4 (HGLMs), or Theorem 5 (posterior MGFs/moments).« less

  1. Social anxiety and social norms in individualistic and collectivistic countries

    PubMed Central

    Schreier, Sina-Simone; Heinrichs, Nina; Alden, Lynn; Rapee, Ronald M.; Hofmann, Stefan G.; Chen, Junwen; Ja Oh, Kyung; Bögels, Susan

    2010-01-01

    Background Social anxiety is assumed to be related to cultural norms across countries. Heinrichs and colleagues [1] compared individualistic and collectivistic countries and found higher social anxiety and more positive attitudes toward socially avoidant behaviors in collectivistic than in individualistic countries. However, the authors failed to include Latin American countries in the collectivistic group. Methods To provide support for these earlier results within an extended sample of collectivistic countries, 478 undergraduate students from individualistic countries were compared with 388 undergraduate students from collectivistic countries (including East Asian and Latin American) via self report of social anxiety and social vignettes assessing social norms. Results As expected, the results of Heinrichs and colleagues [1] were replicated for the individualistic and Asian countries but not for Latin American countries. Latin American countries displayed the lowest social anxiety levels, whereas the collectivistic East Asian group displayed the highest. Conclusions These findings indicate that while culture-mediated social norms affect social anxiety and might help to shed light on the etiology of social anxiety disorder, the dimension of individualism-collectivism may not fully capture the relevant norms. PMID:21049538

  2. Social anxiety and social norms in individualistic and collectivistic countries.

    PubMed

    Schreier, Sina-Simone; Heinrichs, Nina; Alden, Lynn; Rapee, Ronald M; Hofmann, Stefan G; Chen, Junwen; Oh, Kyung Ja; Bögels, Susan

    2010-12-01

    Social anxiety is assumed to be related to cultural norms across countries. Heinrichs et al. [2006: Behav Res Ther 44:1187-1197] compared individualistic and collectivistic countries and found higher social anxiety and more positive attitudes toward socially avoidant behaviors in collectivistic rather than in individualistic countries. However, the authors failed to include Latin American countries in the collectivistic group. To provide support for these earlier results within an extended sample of collectivistic countries, 478 undergraduate students from individualistic countries were compared with 388 undergraduate students from collectivistic countries (including East Asian and Latin American) via self-report of social anxiety and social vignettes assessing social norms. As expected, the results of Heinrichs et al. [2006: Behav Res Ther 44:1187-1197] were replicated for the individualistic and Asian countries, but not for Latin American countries. Latin American countries displayed the lowest social anxiety levels, whereas the collectivistic East Asian group displayed the highest. These findings indicate that while culture-mediated social norms affect social anxiety and might help to shed light on the etiology of social anxiety disorder, the dimension of individualism-collectivism may not fully capture the relevant norms. © 2010 Wiley-Liss, Inc.

  3. The "is" and the "ought": How do perceived social norms influence safety behaviors at work?

    PubMed

    Fugas, Carla S; Meliá, José L; Silva, Silvia A

    2011-01-01

    Despite a widespread view that social norms have an important contextual influence on health attitudes and behaviors, the impact of normative influences on safety behaviors has received very little attention. The current study proposes that supervisors' and coworkers' descriptive and injunctive safety norms influence proactive and compliance safety behaviors. Longitudinal results from 132 workers in a passenger transportation company support the link between coworkers' descriptive safety norms (at Time 1) and proactive safety practices (at Time 2). Crystallization of supervisor' injunctive safety norms (at Time 2) moderated the effect of coworkers' descriptive safety norms (at Time 1) on self-reported proactive safety behavior (at Time 2). These findings emphasize the differences between supervisors' and coworkers' descriptive and injunctive norms as sources of social influence on compliance and proactive safety behavior.

  4. Norms and Standards for Computer Education (MCA, BCA) through Distance Mode.

    ERIC Educational Resources Information Center

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

    This document presents the norms and standards for computer education in India through distance mode, including the Masters in Computer Applications (MCA) and Bachelor in Computer Applications (BCA) programs. These norms and standards were considered and approved by the Distance Education Council, Indira Gandhi National Open University (India), at…

  5. Using Classroom Scenarios to Reveal Mathematics Teachers' Understanding of Sociomathematical Norms

    ERIC Educational Resources Information Center

    Zembat, Ismail Ozgur; Yasa, Seyit Ali

    2015-01-01

    The purpose of this study was to uncover the degree to which in-service teachers understand sociomathematical norms and the nature of that understanding without having to enter and observe their classes. We therefore developed five classroom scenarios exemplifying classroom interactions shaped by certain sociomathematical norms. We then…

  6. Fruit and vegetable attitudes, norms, and intake in low-income youth

    USDA-ARS?s Scientific Manuscript database

    Fruit and vegetable (FV) attitudes and norms have been shown to influence intake in youth; yet research with low-income youth and studies supplementing self-report with objective measures of intake are lacking. Cross-sectional survey data on self-rated FV intake, FV attitudes, and FV norms were coll...

  7. Gender Norms and Family Planning Practices Among Men in Western Jamaica.

    PubMed

    Walcott, Melonie M; Ehiri, John; Kempf, Mirjam C; Funkhouser, Ellen; Bakhoya, Marion; Aung, Maung; Zhang, Kui; Jolly, Pauline E

    2015-07-01

    The objective of this study was to identify the association between gender norms and family planning practices among men in Western Jamaica. A cross-sectional survey of 549 men aged 19 to 54 years attending or visiting four government-operated hospitals was conducted in 2011. Logistic regression models were used to identify factors associated with taking steps to prevent unwanted pregnancy, intention to have a large family size (three or more children), and fathering children with multiple women. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) were calculated from the models. Reduced odds for taking steps to prevent unwanted pregnancy among men with moderate (AOR = 0.5; 95% CI = 0.3-0.8) and high (AOR = 0.3; 95% CI = 0.1-0.6) support for inequitable gender norms was observed. Desiring large family size was associated with moderate (AOR = 2.0; 95% CI = 1.3-2.5) and high (AOR = 2.6; 95% CI = 1.5-4.3) support for macho scores. For men with two or more children (41%), there were increased odds of fathering children with multiple women among those who had moderate (AOR = 2.1; 95% CI = 1.0-4.4) and high (AOR = 2.4; 95% CI = 1.1-5.6) support for masculinity norms. Support for inequitable gender norms was associated with reduced odds of taking steps to prevent unwanted pregnancy, while support for masculinity norms was associated with desiring a large family size and fathering children with multiple women. These findings highlight the importance of including men and gender norms in family planning programs in Jamaica. © The Author(s) 2014.

  8. The roles of outlet density and norms in alcohol use disorder.

    PubMed

    Ahern, Jennifer; Balzer, Laura; Galea, Sandro

    2015-06-01

    Alcohol outlet density and norms shape alcohol consumption. However, due to analytic challenges we do not know: (a) if alcohol outlet density and norms also shape alcohol use disorder, and (b) whether they act in combination to shape disorder. We applied a new targeted minimum loss-based estimator for rare outcomes (rTMLE) to a general population sample from New York City (N = 4000) to examine the separate and combined relations of neighborhood alcohol outlet density and norms around drunkenness with alcohol use disorder. Alcohol use disorder was assessed using the World Mental Health Comprehensive International Diagnostic Interview (WMH-CIDI) alcohol module. Confounders included demographic and socioeconomic characteristics, as well as history of drinking prior to residence in the current neighborhood. Alcohol use disorder prevalence was 1.78%. We found a marginal risk difference for alcohol outlet density of 0.88% (95% CI 0.00-1.77%), and for norms of 2.05% (95% CI 0.89-3.21%), adjusted for confounders. While each exposure had a substantial relation with alcohol use disorder, there was no evidence of additive interaction between the exposures. Results indicate that the neighborhood environment shapes alcohol use disorder. Despite the lack of additive interaction, each exposure had a substantial relation with alcohol use disorder and our findings suggest that alteration of outlet density and norms together would likely be more effective than either one alone. Important next steps include development and testing of multi-component intervention approaches aiming to modify alcohol outlet density and norms toward reducing alcohol use disorder. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Acceleration methods for multi-physics compressible flow

    NASA Astrophysics Data System (ADS)

    Peles, Oren; Turkel, Eli

    2018-04-01

    In this work we investigate the Runge-Kutta (RK)/Implicit smoother scheme as a convergence accelerator for complex multi-physics flow problems including turbulent, reactive and also two-phase flows. The flows considered are subsonic, transonic and supersonic flows in complex geometries, and also can be either steady or unsteady flows. All of these problems are considered to be a very stiff. We then introduce an acceleration method for the compressible Navier-Stokes equations. We start with the multigrid method for pure subsonic flow, including reactive flows. We then add the Rossow-Swanson-Turkel RK/Implicit smoother that enables performing all these complex flow simulations with a reasonable CFL number. We next discuss the RK/Implicit smoother for time dependent problem and also for low Mach numbers. The preconditioner includes an intrinsic low Mach number treatment inside the smoother operator. We also develop a modified Roe scheme with a corresponding flux Jacobian matrix. We then give the extension of the method for real gas and reactive flow. Reactive flows are governed by a system of inhomogeneous Navier-Stokes equations with very stiff source terms. The extension of the RK/Implicit smoother requires an approximation of the source term Jacobian. The properties of the Jacobian are very important for the stability of the method. We discuss what the chemical physics theory of chemical kinetics tells about the mathematical properties of the Jacobian matrix. We focus on the implication of the Le-Chatelier's principle on the sign of the diagonal entries of the Jacobian. We present the implementation of the method for turbulent flow. We use a two RANS turbulent model - one equation model - Spalart-Allmaras and a two-equation model - k-ω SST model. The last extension is for two-phase flows with a gas as a main phase and Eulerian representation of a dispersed particles phase (EDP). We present some examples for such flow computations inside a ballistic evaluation

  10. Sociometric network structure and its association with methamphetamine use norms among homeless youth

    PubMed Central

    Barman-Adhikari, Anamika; Begun, Stephanie; Rice, Eric; Yoshioka-Maxwell, Amanda; Perez-Portillo, Andrea

    2016-01-01

    Homeless youths' social networks are consistently linked with their substance use. Social networks influence behavior through several mechanisms, especially social norms. This study used sociometric analyses to understand whether social norms of drug use behaviors are clustered in network structures and whether these perceived norms (descriptive and injunctive) influence youths' drug use behaviors. An event-based approach was used to delineate boundaries of the two sociometric networks of homeless youth, one in Los Angeles, CA (n = 160) and the other in Santa Monica, CA (n = 130). Network characteristics included centrality (i.e., popularity) and cohesiveness (location in dense subnetworks). The primary outcome was recent methamphetamine use. Results revealed that both descriptive and injunctive norms influenced methamphetamine use. Network cohesion was found to be associated with perception of both descriptive and injunctive norms in both networks, however in opposite directions. Network interventions therefore might be effective if designed to capitalize on social influence that naturally occurs in cohesive parts of networks. PMID:27194667

  11. Condomless Sex Among Homeless Youth: The Role of Multidimensional Social Norms and Gender.

    PubMed

    Barman-Adhikari, Anamika; Hsu, Hsun-Ta; Begun, Stephanie; Portillo, Andrea Perez; Rice, Eric

    2017-03-01

    Most studies of condomless sex among homeless youth have focused on peer norms, while excluding other potentially pertinent influences. This study explored how different types of relationships contributed to norms about condomless sex and whether such norms were associated with engagement in condomless sex among homeless youth. Additionally, because recent work has noted gender differences in social networks of male and female homeless youth, gender differences in social network norms of condomless sex were also assessed. Egocentric network data were collected from homeless youth accessing services at two drop-in centers in Los Angeles, CA (N = 976). Multivariate analyses (non-stratified and stratified by gender) assessed associations between descriptive, injunctive, and communicative norms and participants' engagement in condomless sex. Multivariate analyses indicated that perception of peer condom use and communication with sexual partners were significantly associated with not engaging in condomless sex. These relationships, however, varied by gender. Implications for interventions are discussed.

  12. The Role of Indian Caste Identity and Caste Inconsistent Norms on Status Representation

    PubMed Central

    Sankaran, Sindhuja; Sekerdej, Maciek; von Hecker, Ulrich

    2017-01-01

    The Indian caste system is a complex social structure wherein social roles like one’s profession became ‘hereditary,’ resulting in restricted social mobility and fixed status hierarchies. Furthermore, we argue that the inherent property of caste heightens group identification with one’s caste. Highly identified group members would protect the identity of the group in situations when group norms are violated. In this paper, we were interested in examining the consequence of caste norm violation and how an individual’s status is mentally represented. High caste norms are associated with moral values while the lower caste norms are associated with immorality. We predicted a ‘black sheep effect,’ that is, when high caste individuals’ group identity (caste norm violation condition) is threatened their salient high caste identity would increase, thereby resulting in devaluing the status of their fellow in-group member if the latter is perceived as perpetrator. We presented participants with a social conflict situation of a victim and a perpetrator that is ‘Caste norm consistent’ (Lower caste individual as a perpetrator and higher caste individual as a victim) and vice versa ‘Caste norm inconsistent’ condition (higher caste individual as perpetrator and lower caste individual as a victim). Then, participants had to choose from nine pictorial depictions representing the protagonists in the story on a vertical line, with varying degrees of status distance. Results showed evidence for the black sheep effect and, furthermore, revealed that no other identity (religious, national, and regional) resulted in devaluing the status of fellow in-group member. These results help us understand the ‘black sheep’ effect in the context of moral norms and status representation and are discussed in the framework of the Indian society. PMID:28408896

  13. Mixed-norm estimates for the M/EEG inverse problem using accelerated gradient methods.

    PubMed

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-04-07

    Magneto- and electroencephalography (M/EEG) measure the electromagnetic fields produced by the neural electrical currents. Given a conductor model for the head, and the distribution of source currents in the brain, Maxwell's equations allow one to compute the ensuing M/EEG signals. Given the actual M/EEG measurements and the solution of this forward problem, one can localize, in space and in time, the brain regions that have produced the recorded data. However, due to the physics of the problem, the limited number of sensors compared to the number of possible source locations, and measurement noise, this inverse problem is ill-posed. Consequently, additional constraints are needed. Classical inverse solvers, often called minimum norm estimates (MNE), promote source estimates with a small ℓ₂ norm. Here, we consider a more general class of priors based on mixed norms. Such norms have the ability to structure the prior in order to incorporate some additional assumptions about the sources. We refer to such solvers as mixed-norm estimates (MxNE). In the context of M/EEG, MxNE can promote spatially focal sources with smooth temporal estimates with a two-level ℓ₁/ℓ₂ mixed-norm, while a three-level mixed-norm can be used to promote spatially non-overlapping sources between different experimental conditions. In order to efficiently solve the optimization problems of MxNE, we introduce fast first-order iterative schemes that for the ℓ₁/ℓ₂ norm give solutions in a few seconds making such a prior as convenient as the simple MNE. Furthermore, thanks to the convexity of the optimization problem, we can provide optimality conditions that guarantee global convergence. The utility of the methods is demonstrated both with simulations and experimental MEG data.

  14. Mixed-norm estimates for the M/EEG inverse problem using accelerated gradient methods

    PubMed Central

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-01-01

    Magneto- and electroencephalography (M/EEG) measure the electromagnetic fields produced by the neural electrical currents. Given a conductor model for the head, and the distribution of source currents in the brain, Maxwell’s equations allow one to compute the ensuing M/EEG signals. Given the actual M/EEG measurements and the solution of this forward problem, one can localize, in space and in time, the brain regions than have produced the recorded data. However, due to the physics of the problem, the limited number of sensors compared to the number of possible source locations, and measurement noise, this inverse problem is ill-posed. Consequently, additional constraints are needed. Classical inverse solvers, often called Minimum Norm Estimates (MNE), promote source estimates with a small ℓ2 norm. Here, we consider a more general class of priors based on mixed-norms. Such norms have the ability to structure the prior in order to incorporate some additional assumptions about the sources. We refer to such solvers as Mixed-Norm Estimates (MxNE). In the context of M/EEG, MxNE can promote spatially focal sources with smooth temporal estimates with a two-level ℓ1/ℓ2 mixed-norm, while a three-level mixed-norm can be used to promote spatially non-overlapping sources between different experimental conditions. In order to efficiently solve the optimization problems of MxNE, we introduce fast first-order iterative schemes that for the ℓ1/ℓ2 norm give solutions in a few seconds making such a prior as convenient as the simple MNE. Furhermore, thanks to the convexity of the optimization problem, we can provide optimality conditions that guarantee global convergence. The utility of the methods is demonstrated both with simulations and experimental MEG data. PMID:22421459

  15. Longitudinal relationships between individual and class norms supporting dating violence and perpetration of dating violence.

    PubMed

    Taylor, Katherine A; Sullivan, Terri N; Farrell, Albert D

    2015-03-01

    Dating violence is commonly perpetrated in adolescence, making it imperative to understand risk factors in order to inform prevention efforts. Although individual norms supporting dating violence are strongly related to its perpetration, few studies have examined their longitudinal impact. Moreover, the influence of class norms (i.e., norms for students in the same grade, cohort, and school) supporting dating violence on perpetration has rarely been studied. The current study examined longitudinal relationships between individual and class norms supporting dating violence and perpetration of physical and psychological dating violence. Participants were two cohorts of sixth graders from 37 schools who were in dating relationships at Wave 1 and 6 months later at Wave 2 (N = 2,022; 43% female; 52% African American, 21% Latino/a, 20% White, and 7% other). The analyses used a multilevel approach, with students represented at Level 1 and classes (n = 74) at Level 2. The models tested direct effects of Wave 1 individual and class norms supporting dating violence on subsequent changes in perpetration of dating violence at Wave 2 and the extent to which gender moderated these relationships. The findings indicated that greater individual norms supporting male dating violence predicted greater change in perpetration of physical and psychological dating violence and greater individual norms supporting female dating violence predicted greater change in perpetration of psychological dating violence. Greater class norms supporting male dating violence predicted greater change in perpetration of physical dating violence; whereas greater class norms supporting female dating violence predicted less change in perpetration of physical dating violence. These findings highlight the need to address norms in early adolescence.

  16. Social norms and its correlates as a pathway to smoking among young Latino adults.

    PubMed

    Echeverría, Sandra E; Gundersen, Daniel A; Manderski, Michelle T B; Delnevo, Cristine D

    2015-01-01

    Socially and culturally embedded norms regarding smoking may be one pathway by which individuals adopt smoking behaviors. However, few studies have examined if social norms operate in young adults, a population at high risk of becoming regular smokers. There is also little research examining correlates of social norms in populations with a large immigrant segment, where social norms are likely to differ from the receiving country and could contribute to a better understanding of previously reported acculturation-health associations. Using data from a nationally representative sample of young adults in the United States reached via a novel cell-phone sampling design, we explored the relationships between acculturation proxies (nativity, language spoken and generational status), socioeconomic position (SEP), smoking social norms and current smoking status among Latinos 18-34 years of age (n = 873). Specifically, we examined if a measure of injunctive norms assessed by asking participants about the acceptability of smoking among Latino co-ethnic peers was associated with acculturation proxies and SEP. Results showed a strong gradient in smoking social norms by acculturation proxies, with significantly less acceptance of smoking reported among the foreign-born and increasing acceptance among those speaking only/mostly English at home and third-generation individuals. No consistent and significant pattern in smoking social norms was observed by education, income or employment status, possibly due to the age of the study population. Lastly, those who reported that their Latino peers do not find smoking acceptable were significantly less likely to be current smokers compared to those who said their Latino peers were ambivalent about smoking (do not care either way) in crude models, and in models that adjusted for age, sex, generational status, language spoken, and SEP. This study provides new evidence regarding the role of social norms in shaping smoking behaviors among

  17. Social norms and its correlates as a pathway to smoking among young Latino adults

    PubMed Central

    Echeverría, Sandra E.; Gundersen, Daniel A.; Manderski, Michelle T.B.; Delnevo, Cristine D.

    2014-01-01

    Socially and culturally embedded norms regarding smoking may be one pathway by which individuals adopt smoking behaviors. However, few studies have examined if social norms operate in young adults, a population at high risk of becoming regular smokers. There is also little research examining correlates of social norms in populations with a large immigrant segment, where social norms are likely to differ from the receiving country and could contribute to a better understanding of previously reported acculturation-health associations. Using data from a nationally representative sample of young adults in the United States reached via a novel cell-phone sampling design, we explored the relationships between acculturation proxies (nativity, language spoken and generational status), socioeconomic position (SEP), smoking social norms and current smoking status among Latinos 18–34 years of age (n=873). Specifically, we examined if a measure of injunctive norms assessed by asking participants about the acceptability of smoking among Latino co-ethnic peers was associated with acculturation proxies and SEP. Results showed a strong gradient in smoking social norms by acculturation proxies, with significantly less acceptance of smoking reported among the foreign-born and increasing acceptance among those speaking only/ mostly English at home and third-generation individuals. No consistent and significant pattern in smoking social norms was observed by education, income or employment status, possibly due to the age of the study population. Lastly, those who reported that their Latino peers do not find smoking acceptable were significantly less likely to be current smokers compared to those who said their Latino peers were ambivalent about smoking (do not care either way) in crude models, and in models that adjusted for age, sex, generational status, language spoken, and SEP. This study provides new evidence regarding the role of social norms in shaping smoking behaviors among

  18. The spatiotemporal MEG covariance matrix modeled as a sum of Kronecker products.

    PubMed

    Bijma, Fetsje; de Munck, Jan C; Heethaar, Rob M

    2005-08-15

    The single Kronecker product (KP) model for the spatiotemporal covariance of MEG residuals is extended to a sum of Kronecker products. This sum of KP is estimated such that it approximates the spatiotemporal sample covariance best in matrix norm. Contrary to the single KP, this extension allows for describing multiple, independent phenomena in the ongoing background activity. Whereas the single KP model can be interpreted by assuming that background activity is generated by randomly distributed dipoles with certain spatial and temporal characteristics, the sum model can be physiologically interpreted by assuming a composite of such processes. Taking enough terms into account, the spatiotemporal sample covariance matrix can be described exactly by this extended model. In the estimation of the sum of KP model, it appears that the sum of the first 2 KP describes between 67% and 93%. Moreover, these first two terms describe two physiological processes in the background activity: focal, frequency-specific alpha activity, and more widespread non-frequency-specific activity. Furthermore, temporal nonstationarities due to trial-to-trial variations are not clearly visible in the first two terms, and, hence, play only a minor role in the sample covariance matrix in terms of matrix power. Considering the dipole localization, the single KP model appears to describe around 80% of the noise and seems therefore adequate. The emphasis of further improvement of localization accuracy should be on improving the source model rather than the covariance model.

  19. Geochemical signature of NORM waste in Brazilian oil and gas industry.

    PubMed

    De-Paula-Costa, G T; Guerrante, I C; Costa-de-Moura, J; Amorim, F C

    2018-09-01

    The Brazilian Nuclear Energy Agency (CNEN) is responsible for any radioactive waste storage and disposal in the country. The storage of radioactive waste is carried out in the facilities under CNEN regulation and its disposal is operated, managed and controlled by the CNEN. Oil NORM (Naturally Occurring Radioactive Materials) in this article refers to waste coming from oil exploitation. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of a regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is the modeling of radioisotopes normally present in oil pipe contamination such as 228 Ac, 214 Bi and 214 Pb analyzed by gamma spectrometry. The specific activities of elements from different decay series are plotted in a scatter diagram. This method was successfully tested with gamma spectrometry analyses of oil sludge NORM samples from four different sources obtained from Petrobras reports for the Campos Basin/Brazil. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. PEPAB Norm Development (PEPABNRM)

    DTIC Science & Technology

    1991-01-09

    AD-A249 908A PEPAB NORM DEVELOPMENT (PEPABNRM) ANNUAL REPORT LESLIE CAROL MONTGOMERY PATRICIA A. DEUSTER S AYA V f JANUARY 9, 1991 S~ Supported by...Methods 14 C. Results 15 D . Discussion 16 III. DEVELOPMENT OF A COMPUTERIZED PHYSICAL ACTIVITY QUESTIONNAIRE 16 REFERENCES 20 TABLES 22 FIGURES 26 ANNUAL...group after the AC test was over 11 mM, even with the 30-sec rest inter- vals during which lactate could be removed. 3. Discussion In conclusion, the

  1. Contradictory sexual norms and expectations for young people in rural Northern Tanzania.

    PubMed

    Wight, Daniel; Plummer, Mary L; Mshana, Gerry; Wamoyi, Joyce; Shigongo, Zachayo S; Ross, David A

    2006-02-01

    There has been a long-running debate as to whether sexual cultures in sub-Saharan Africa are permissive or characterised by restrictive rules, rituals and self-restraint. This paper, based on participant observation data, outlines the main features of sexual culture in rural northern Tanzania and highlights both permissive and restrictive norms and expectations for young people. It also illustrates how sexual beliefs are socially constructed and subject to social change. Sexual activity is constrained by clear norms of school pupil abstinence, female sexual respectability and taboos around the discussion of sex. However, these norms are incompatible with several widely held expectations: that sexual activity is inevitable unless prevented, sex is a female resource to be exploited, restrictions on sexual activity are relaxed at festivals, and masculine esteem is boosted through sexual experience. Differential commitment to these norms and expectations reflects conflicts between generations and genders. Young people appear to manage the contradictions in these norms by concealing their sexual relationships. This almost certainly contributes to their short duration and the high levels of partner change, since relationships are not reinforced through social recognition and there is little scope to develop intimacy through non-sexual contacts.

  2. Relationship between Norm-internalization and Cooperation in N-person Prisoners' Dilemma Games

    NASA Astrophysics Data System (ADS)

    Matsumoto, Mitsutaka

    In this paper, I discuss the problems of ``order in social situations'' using a computer simulation of iterated N-person prisoners' dilemma game. It has been claimed that, in the case of the 2-person prisoners' dilemma, repetition of games and the reciprocal use of the ``tit-for-tat'' strategy promote the possibility of cooperation. However, in cases of N-person prisoners' dilemma where N is greater than 2, the logic does not work effectively. The most essential problem is so called ``sanctioning problems''. In this paper, firstly, I discuss the ``sanctioning problems'' which were introduced by Axelrod and Keohane in 1986. Based on the model formalized by Axelrod, I propose a new model, in which I added a mechanism of players' payoff changes in the Axelrod's model. I call this mechanism norm-internalization and call our model ``norm-internalization game''. Second, by using the model, I investigated the relationship between agents' norm-internalization (payoff-alternation) and the possibilities of cooperation. The results of computer simulation indicated that unequal distribution of cooperating norm and uniform distribution of sanctioning norm are more effective in establishing cooperation. I discuss the mathematical features and the implications of the results on social science.

  3. How gender- and violence-related norms affect self-esteem among adolescent refugee girls living in Ethiopia.

    PubMed

    Stark, L; Asghar, K; Seff, I; Cislaghi, B; Yu, G; Tesfay Gessesse, T; Eoomkham, J; Assazenew Baysa, A; Falb, K

    2018-01-01

    Evidence suggests adolescent self-esteem is influenced by beliefs of how individuals in their reference group perceive them. However, few studies examine how gender- and violence-related social norms affect self-esteem among refugee populations. This paper explores relationships between gender inequitable and victim-blaming social norms, personal attitudes, and self-esteem among adolescent girls participating in a life skills program in three Ethiopian refugee camps. Ordinary least squares multivariable regression analysis was used to assess the associations between attitudes and social norms, and self-esteem. Key independent variables of interest included a scale measuring personal attitudes toward gender inequitable norms, a measure of perceived injunctive norms capturing how a girl believed her family and community would react if she was raped, and a peer-group measure of collective descriptive norms surrounding gender inequity. The key outcome variable, self-esteem, was measured using the Rosenberg self-esteem scale. Girl's personal attitudes toward gender inequitable norms were not significantly predictive of self-esteem at endline, when adjusting for other covariates. Collective peer norms surrounding the same gender inequitable statements were significantly predictive of self-esteem at endline ( ß  = -0.130; p   =  0.024). Additionally, perceived injunctive norms surrounding family and community-based sanctions for victims of forced sex were associated with a decline in self-esteem at endline ( ß  = -0.103; p   =  0.014). Significant findings for collective descriptive norms and injunctive norms remained when controlling for all three constructs simultaneously. Findings suggest shifting collective norms around gender inequity, particularly at the community and peer levels, may sustainably support the safety and well-being of adolescent girls in refugee settings.

  4. Encoded Exposure and Social Norms in Entertainment-Education.

    PubMed

    Riley, Amy Henderson; Sood, Suruchi; Mazumdar, Paramita Dasgupta; Choudary, Narendra Nath; Malhotra, Alka; Sahba, Naysan

    2017-01-01

    Entertainment-education is an effective health communication strategy that combines or embeds educational messages into entertainment programs to bring about social and behavior change. For years, scholars have considered how entertainment-education works. Some contemporary theories posit that entertainment-education does not engender behavior change directly but does so through mediating variables. This study adds to the literature on this topic by exploring the direct relationship between exposure and social norms instead of their relationship through behavior as a mediator. Novel to this study is the use of encoded exposure, a continuous and recognition-based measure of exposure that includes ever watching, recall, involvement, and dose in its operationalization. Using cross-sectional data from Kyunki … Jeena Issi Ka Naam Hai, an entertainment-education program in India, this exploratory analysis indicates a positive and significant relationship between encoded exposure and social norms. How can this finding be applied to future programs? Questions remain, and replication is needed, but if it is not essential to go through behavior in order to change social norms, then implications emerge for the theory and practice of entertainment-education.

  5. Systematic approach to characterisation of NORM in Thailand.

    PubMed

    Chanyotha, S; Kranrod, C; Pengvanich, P

    2015-11-01

    The aim of this article is to provide information on the systematic approach that has been developed for the measurement of natural radiation exposure and the characterisation of naturally occurring radioactive materials (NORM) in terms of occurrence and distribution in various industrial processes, including the produced waste from the mineral industries in Thailand. The approach can be adapted for various types of study areas. The importance of collaboration among research institutions is discussed. Some developments include 25 documents; the redesign of the field equipment, such as the gamma survey meter, for convenient access to conduct measurement in various study areas; the method to collect and analyse radon gas from a natural gas pipeline and the manganese dioxide fibre to adsorb radium on-site for laboratory analysis. The NORM project in Thailand has been carried out for more than 10 y to support the development of NORM regulation in Thailand. In the previous studies as well as current, international standards for action levels have been adopted for safety purpose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. “Who Doesn’t?”—The Impact of Descriptive Norms on Corruption

    PubMed Central

    Köbis, Nils C.; van Prooijen, Jan-Willem; Righetti, Francesca; Van Lange, Paul A. M.

    2015-01-01

    Corruption poses one of the major societal challenges of our time. Considerable advances have been made in understanding corruption on a macro level, yet the psychological antecedents of corrupt behavior remain largely unknown. In order to explain why some people engage in corruption while others do not, we explored the impact of descriptive social norms on corrupt behavior by using a novel behavioral measure of corruption. We conducted three studies to test whether perceived descriptive norms of corruption (i.e. the belief about the prevalence of corruption in a specific context) influence corrupt behavior. The results indicated that descriptive norms highly correlate with corrupt behavior—both when measured before (Study 1) or after (Study 2) the behavioral measure of corruption. Finally, we adopted an experimental design to investigate the causal effect of descriptive norms on corruption (Study 3). Corrupt behavior in the corruption game significantly drops when participants receive short anti-corruption descriptive norm primes prior to the game. These findings indicate that perceived descriptive norms can impact corrupt behavior and, possibly, could offer an explanation for inter-personal and inter-cultural variation in corrupt behavior in the real world. We discuss implications of these findings and draw avenues for future research. PMID:26121127

  7. Effectiveness of social norms media marketing in reducing drinking and driving: A statewide campaign.

    PubMed

    Perkins, H Wesley; Linkenbach, Jeffrey W; Lewis, Melissa A; Neighbors, Clayton

    2010-10-01

    This research evaluated the efficacy of a high-intensity social norms media marketing campaign aimed at correcting normative misperceptions and reducing the prevalence of drinking and driving among 21-to-34-year-olds in Montana. A quasi-experimental design was used, such that regions of Montana were assigned to one of three experimental groups: social norms media marketing campaign, buffer, and control. Four random samples of Montanans between the ages of 21 and 34 were assessed at four time points over 18 months via phone surveys. Findings suggest that the social norms media campaign was successful at exposing the targeted population to social norms messages in the counties within the intervention region. Moreover, results demonstrate the campaign reduced normative misperceptions, increased use of designated drivers, and decreased drinking and driving among those young adults in counties within the intervention region. Social norms media marketing can be effective at changing drinking-related behaviors at the population level. This research provides a model for utilizing social norms media marketing to address other behaviors related to public health. 2010 Elsevier Ltd. All rights reserved.

  8. Effectiveness of social norms media marketing in reducing drinking and driving: A statewide campaign

    PubMed Central

    Linkenbach, Jeffrey W.; Lewis, Melissa A.; Neighbors, Clayton

    2016-01-01

    This research evaluated the efficacy of a high-intensity social norms media marketing campaign aimed at correcting normative misperceptions and reducing the prevalence of drinking and driving among 21-to-34-year-olds in Montana. A quasi-experimental design was used, such that regions of Montana were assigned to one of three experimental groups: social norms media marketing campaign, buffer, and control. Four random samples of Montanans between the ages of 21 and 34 were assessed at four time points over 18 months via phone surveys. Findings suggest that the social norms media campaign was successful at exposing the targeted population to social norms messages in the counties within the intervention region. Moreover, results demonstrate the campaign reduced normative misperceptions, increased use of designated drivers, and decreased drinking and driving among those young adults in counties within the intervention region. Social norms media marketing can be effective at changing drinking-related behaviors at the population level. This research provides a model for utilizing social norms media marketing to address other behaviors related to public health. PMID:20619177

  9. Role of gender norms and group identification on hypothetical and experimental pain tolerance.

    PubMed

    Pool, Gregory J; Schwegler, Andria F; Theodore, Brian R; Fuchs, Perry N

    2007-05-01

    Previous research indicates that men typically tolerate more pain in experimental settings than women. One likely explanation for these group differences in pain tolerance is conformity to traditional, gender group social norms (i.e., the ideal man is masculine and tolerates more pain; the ideal woman is feminine and tolerates less pain). According to self-categorization theory, norms guide behavior to the degree that group members adopt the group identity. Therefore, high-identifying men are expected to conform to gender norms and tolerate more pain than high-identifying women who conform to different gender norms as a guide for their behavior. We conducted two studies to investigate whether gender group identification moderates individuals' conformity to pain tolerance and reporting norms. In the first study, participants indicated their gender identification and expected tolerance of a hypothetical painful stimulus. As anticipated, high-identifying men reported significantly greater pain tolerance than high-identifying women. No differences existed between low-identifying men and women. To determine if self-reported pain tolerance in a role-playing scenario corresponds to actual pain tolerance in an experimental setting, the second study examined pain tolerance to a noxious stimulus induced by electrical stimulation of the index finger. The experimental outcome revealed that high-identifying men tolerated more painful stimulation than high-identifying women. Further, high-identifying men tolerated more pain than low-identifying men. These results highlight the influence of social norms on behavior and suggest the need to further explore the role of norms in pain reporting behaviors.

  10. Mythology of the Norm: Disrupting the Culture of Bullying in Schools

    ERIC Educational Resources Information Center

    Miller, S. J.

    2012-01-01

    The mythology of the "norm" has direct repercussions for schools, and its ideological reinforcement is the primary cause of bullying today. Though it is difficult to pinpoint an origin for "the norm," the medical model and its systemic structural power is one powerful institution that perpetuates this mythology. The medical model has a biological…

  11. Can Civility Norms Boost Positive Effects of Management Commitment to Safety?

    PubMed

    McGonagle, Alyssa K; Childress, Niambi M; Walsh, Benjamin M; Bauerle, Timothy J

    2016-07-03

    We proposed that civility norms would strengthen relationships between management commitment to safety and workers' safety motivation, safety behaviors, and injuries. Survey data were obtained from working adults in hazardous jobs-those for which physical labor is required and/or a realistic possibility of physical injury is present (N = 290). Results showed that management commitment positively related to workers' safety motivation, safety participation, and safety compliance, and negatively related to minor injuries. Furthermore, management commitment to safety displayed a stronger positive relationship with safety motivation and safety participation, and a stronger negative relationship with minor worker injuries when civility norms were high (versus low). The results confirm existing known relationships between management commitment to safety and worker safety motivation and behavior; furthermore, civility norms facilitate the relationships between management commitment to safety and various outcomes important to worker safety. In order to promote an optimally safe working environment, managers should demonstrate a commitment to worker safety and promote positive norms for interpersonal treatment between workers in their units.

  12. The relevance of moral norms in distinct relational contexts: Purity versus harm norms regulate self-directed actions

    PubMed Central

    Dungan, James A.; Chakroff, Alek; Young, Liane

    2017-01-01

    Recent efforts to partition the space of morality have focused on the descriptive content of distinct moral domains (e.g., harm versus purity), or alternatively, the relationship between the perpetrator and victim of moral violations. Across three studies, we demonstrate that harm and purity norms are relevant in distinct relational contexts. Moral judgments of purity violations, compared to harm violations, are relatively more sensitive to the negative impact perpetrators have on themselves versus other victims (Study 1). This pattern replicates across a wide array of harm and purity violations varying in severity (Studies 2 and 3). Moreover, while perceptions of harm predict moral judgment consistently across relational contexts, perceptions of purity predict moral judgment more for self-directed actions, where perpetrators violate themselves, compared to dyadic actions, where perpetrators violate other victims (Study 3). Together, these studies reveal how an action’s content and its relational context interact to influence moral judgment, providing novel insights into the adaptive functions of harm and purity norms. PMID:28278214

  13. ℓ p-Norm Multikernel Learning Approach for Stock Market Price Forecasting

    PubMed Central

    Shao, Xigao; Wu, Kun; Liao, Bifeng

    2012-01-01

    Linear multiple kernel learning model has been used for predicting financial time series. However, ℓ 1-norm multiple support vector regression is rarely observed to outperform trivial baselines in practical applications. To allow for robust kernel mixtures that generalize well, we adopt ℓ p-norm multiple kernel support vector regression (1 ≤ p < ∞) as a stock price prediction model. The optimization problem is decomposed into smaller subproblems, and the interleaved optimization strategy is employed to solve the regression model. The model is evaluated on forecasting the daily stock closing prices of Shanghai Stock Index in China. Experimental results show that our proposed model performs better than ℓ 1-norm multiple support vector regression model. PMID:23365561

  14. ℓ(p)-Norm multikernel learning approach for stock market price forecasting.

    PubMed

    Shao, Xigao; Wu, Kun; Liao, Bifeng

    2012-01-01

    Linear multiple kernel learning model has been used for predicting financial time series. However, ℓ(1)-norm multiple support vector regression is rarely observed to outperform trivial baselines in practical applications. To allow for robust kernel mixtures that generalize well, we adopt ℓ(p)-norm multiple kernel support vector regression (1 ≤ p < ∞) as a stock price prediction model. The optimization problem is decomposed into smaller subproblems, and the interleaved optimization strategy is employed to solve the regression model. The model is evaluated on forecasting the daily stock closing prices of Shanghai Stock Index in China. Experimental results show that our proposed model performs better than ℓ(1)-norm multiple support vector regression model.

  15. Deference in Indians' decision making: introjected goals or injunctive norms?

    PubMed

    Savani, Krishna; Morris, Michael W; Naidu, N V R

    2012-04-01

    We examine the claim that Indians are more likely than Americans to act deferentially in the presence of authority figures and explore 2 possible psychological mechanisms for this cultural difference: introjected goals and injunctive norms. Studies 1 and 2 showed that after reflecting upon an authority's expectations, Indians were more likely than Americans to make clothing and course choices consistent with the authority's expectations, but there was no such cultural difference for peers' expectations. Study 3 showed that merely activating the concept of authority figures, without highlighting specific expectations, was sufficient to influence Indians' choices but not their evaluations. Examining a more basic distinction underlying introjected goals versus injunctive norms, Study 4 showed that authority primes influenced Indians' sense of what they should do but not what they want to do. Study 5 showed that, inconsistent with the internalized goal mechanism, the effect of explicit authority primes did not increase after brief delays. However, Indian participants who were less likely to accommodate to the salient authority experienced more guilt across delay conditions, which supported the injunctive norms mechanism. The findings suggest that manipulating injunctive norms can be an effective means for inducing or eliminating deferential behaviors in Indian settings. (c) 2012 APA, all rights reserved.

  16. Descriptive and injunctive norms of waterpipe smoking among college students.

    PubMed

    Leavens, Eleanor L S; Brett, Emma I; Morgan, Taylor L; Lopez, Susanna V; Shaikh, Raees A; Leffingwell, Thad R; Wagener, Theodore L

    2018-02-01

    Smoking tobacco via a waterpipe (WP) is on the rise, particularly among college students. One reason for this may be normative perceptions of WP tobacco smoking (WTS) among this population. The current study examined the perceived and actual descriptive and injunctive norms of WTS among a college student sample. Participants were 894 college students enrolled at a large, Midwestern university. Participants completed measures of WTS frequency and quantity and perceived/actual descriptive and injunctive norms of WTS. Over one-third of the sample reported ever trying WTS, while only 2% reported current (past month) use. When comparing ever and never WP smokers, ever smokers reported greater perceived peer approval of WTS. Both males and females overestimated WTS frequency of same-sex students at their university. The current study is one of the first to investigate descriptive and injunctive norms of WTS among college students. Students who report WTS are more likely to overestimate descriptive norms of WTS among their peers, suggesting corrective normative feedback regarding actual use by peers may be an important target for WTS intervention among college students. Future research should investigate the temporal association between normative perceptions and WTS behaviors among college students. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Dopamine-System Genes and Cultural Acquisition: The Norm Sensitivity Hypothesis

    PubMed Central

    Kitayama, Shinobu; King, Anthony; Hsu, Ming; Liberzon, Israel; Yoon, Carolyn

    2016-01-01

    Previous research in cultural psychology shows that cultures vary in the social orientation of independence and interdependence. To date, however, little is known about how people may acquire such global patterns of cultural behavior or cultural norms. Nor is it clear what genetic mechanisms may underlie the acquisition of cultural norms. Here, we draw on recent evidence for certain genetic variability in the susceptibility to environmental influences and propose a norm sensitivity hypothesis, which holds that people acquire culture, and rules of cultural behaviors, through reinforcement-mediated social learning processes. One corollary of the hypothesis is that the degree of cultural acquisition should be influenced by polymorphic variants of genes involved in dopaminergic neural pathways, which have been widely implicated in reinforcement learning. We reviewed initial evidence for this prediction and discussed challenges and directions for future research. PMID:28491931

  18. RxTerms - a drug interface terminology derived from RxNorm.

    PubMed

    Fung, Kin Wah; McDonald, Clement; Bray, Bruce E

    2008-11-06

    A good interface terminology is an essential component of any Computerized Provider Order Entry system. RxTerms is a drug interface terminology derived from RxNorm. By reorganizing the drug information into two dimensions as prescribers do when writing prescriptions and by eliminating drug names that are less likely to be needed in a prescribing environment, RxTerms helps the user to efficiently enter complete prescription orders. Preliminary evaluation of RxTerms using a list of most commonly prescribed drugs showed that its coverage was very good (99% for both generic and branded drug names). There was significant efficiency gain compared to using the unprocessed RxNorm names. RxTerms fills the gap for a free, up-to-date drug interface terminology that is linked to RxNorm, the U.S. designated standard for clinical drugs.

  19. Clinician attitudes, social norms and intentions to use a computer-assisted intervention.

    PubMed

    Buti, Allison L; Eakins, Danielle; Fussell, Holly; Kunkel, Lynn E; Kudura, Aisha; McCarty, Dennis

    2013-04-01

    The National Drug Abuse Treatment Clinical Trials Network (CTN) works to bridge the gap between research and practice and tested a Web-delivered psychosocial intervention (the Therapeutic Education System, TES) in 10 community treatment centers. Computer-assisted therapies, such as Web-delivered interventions, may improve the consistency and efficiency of treatment for alcohol and drug use disorders. Prior to the start of the study, we surveyed counselors (N=96) in participating treatment centers and assessed counselor attitudes, perceived social norms and intentions to use a Web-delivered intervention. Analysis of the intention to adopt a Web-delivered intervention assessed the influence of attitudes and perceived social norms. Perceived social norms were a significant contributor to clinician intention to adopt Web-based interventions while attitude was not. To promote successful implementation, it may be helpful to create social norms supportive of computer-assisted therapies. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Fruit and Vegetable Attitudes, Norms, and Intake in Low-Income Youth

    ERIC Educational Resources Information Center

    Di Noia, Jennifer; Cullen, Karen Weber

    2015-01-01

    Fruit and vegetable (FV) attitudes and norms have been shown to influence intake in youth; yet research with low-income youth and studies supplementing self-report with objective measures of intake are lacking. Cross-sectional survey data on self-rated FV intake, FV attitudes, and FV norms were collected in a sample of 116 youth attending a…

  1. First, Third, and Fifth Grade Children's Attitudes about Gender Norm Violations.

    ERIC Educational Resources Information Center

    Blakemore, Judith E. Owen

    This questionnaire study examined elementary school student's knowledge of a number of gender norms as well as some moral and social norms. Participating in the study were 111 first, third, and fifth graders, the majority of whom were white, with a small number of Hispanic and Asian children. The gender roles related to children's play, hair…

  2. A Meta-Analysis of the Relations Between Three Types of Peer Norms and Adolescent Sexual Behavior.

    PubMed

    van de Bongardt, Daphne; Reitz, Ellen; Sandfort, Theo; Deković, Maja

    2015-08-01

    The aim of the present meta-analysis was to investigate the associations between three types of peer norms-descriptive norms (peer sexual behaviors), injunctive norms (peer sexual attitudes), and peer pressure to have sex-and two adolescent sexual behavior outcomes (sexual activity and sexual risk behavior). Adolescent sexual activity was more strongly associated with descriptive norms (ESrfixed=.40) than with injunctive norms (ESrfixed=.22) or peer pressure (ESrfixed=.10). Compared with the sexual activity outcome, the effect size for descriptive norms (peer sexual risk behavior) for sexual risk behavior was smaller (ESrfixed=.11). Age, gender, peer type, and socio-cultural context significantly moderated these associations. Additional analyses of longitudinal studies suggested that selection effects were stronger than socialization effects. These findings offer empirical support for the conceptual distinction between three types of peer norms and hold important implications for theory, research, and intervention strategies. © 2014 by the Society for Personality and Social Psychology, Inc.

  3. Social Norms Theory and Concussion Education

    ERIC Educational Resources Information Center

    Kroshus, Emily; Garnett, Bernice R.; Baugh, Christine M.; Calzo, Jerel P.

    2015-01-01

    Secondary prevention of harm from sport-related concussion is contingent on immediate removal from play post-injury. To date, educational efforts to reduce the prevalent risk behavior of continued play while symptomatic have been largely ineffective. Social norms theory may hold promise as a foundation for more effective concussion education aimed…

  4. Gay guys using gay language: friendship, shared values and the intent-context-effect matrix.

    PubMed

    McCormack, Mark; Wignall, Liam; Morris, Max

    2016-12-01

    This article draws on in-depth interviews with 35 openly gay male undergraduates from four universities in England to develop an understanding of the changing nature of language related to homosexuality. In addition to finding a diminution in the prevalence of homophobic language, we demonstrate that participants maintain complex and nuanced understandings of phrases that do not use homophobic pejoratives, such as 'that's so gay'. The majority of participants rejected the notion that these phrases are inherently homophobic, instead arguing that the intent with which they are said and the context in which they are used are vital in understanding their meaning and effect. We conceptualize an intent-context-effect matrix to understand the interdependency of these variables. Highlighting the situated nature of this matrix, we also demonstrate the importance of the existence of shared norms between those saying and hearing the phrase when interpreting such language. © London School of Economics and Political Science 2016.

  5. Brief motivational intervention for college drinking: the synergistic impact of social anxiety and perceived drinking norms.

    PubMed

    Terlecki, Meredith A; Buckner, Julia D; Larimer, Mary E; Copeland, Amy L

    2012-12-01

    Despite the efficacy of Brief Alcohol Screening and Intervention for College Students (BASICS), students with higher social anxiety appear vulnerable to poorer outcomes. A possible explanation for these outcomes is that corrective normative feedback (an active component of BASICS) may be less effective for socially anxious students if their beliefs about others' drinking are less malleable because of intense fear of negative evaluation for deviating from perceived drinking norms. This study evaluated whether socially anxious students demonstrated less change in perceived norms during BASICS. We also examined whether change in norm endorsement moderated the relation between social anxiety and BASICS outcomes. Undergraduates (n = 52) who underwent BASICS completed measures of drinking, social anxiety, and perceived norms at baseline and 4 weeks post-BASICS. Higher social anxiety was related to less change in norm endorsement after receiving BASICS. Change in perceived norms during treatment moderated the relation between social anxiety and follow-up drinking. Among students with smaller change in norm endorsement after BASICS, higher social anxiety was related to heavier follow-up drinking. Among students with greater changes to norm endorsement during BASICS, the effect of social anxiety was nonsignificant. Results suggest that corrective perceived norms interventions may be less effective among socially anxious students, contributing to continued heavy drinking. Development of social anxiety-specific BASICS components warrants attention. 2013 APA, all rights reserved

  6. Brief Motivational Intervention for College Drinking: The Synergistic Impact of Social Anxiety and Perceived Drinking Norms

    PubMed Central

    Terlecki, Meredith A.; Buckner, Julia D.; Larimer, Mary E.; Copeland, Amy L.

    2012-01-01

    Despite the efficacy of Brief Alcohol Screening and Intervention for College Students (BASICS), students with higher social anxiety appear vulnerable to poorer outcomes. A possible explanation for these outcomes is that corrective normative feedback (an active component of BASICS) may be less effective for socially anxious students if their beliefs about others’ drinking are less malleable due to intense fear of negative evaluation for deviating from perceived drinking norms. This study evaluated whether socially anxious students demonstrated less change in perceived norms during BASICS. We also examined whether change in norm endorsement moderated the relation between social anxiety and BASICS outcomes. Undergraduates (N = 52) who underwent BASICS completed measures of drinking, social anxiety, and perceived norms at baseline and 4-weeks post-BASICS. Higher social anxiety was related to less change in norm endorsement after receiving BASICS. Change in perceived norms during treatment moderated the relation between social anxiety and follow-up drinking. Among students with smaller change in norm endorsement after BASICS, higher social anxiety was related to heavier follow-up drinking. Among students with greater changes to norm endorsement during BASICS, the effect of social anxiety was non-significant. Results suggest that corrective perceived norms interventions may be less effective among socially anxious students, contributing to continued heavy drinking. Development of social anxiety-specific BASICS components warrants attention. PMID:22612254

  7. The impact of social norm change strategies on smokers' quitting behaviours.

    PubMed

    Zhang, Xueying; Cowling, David W; Tang, Hao

    2010-04-01

    Using a social norm change paradigm model that reflects the California Tobacco Control Program's (CTCP) priorities, we compare the strength of the relationship of the social norm constructs to key smoking behavioural outcomes. Social norm constructs that correspond to CTCP's priority areas were created from selected California Adult Tobacco Survey knowledge, attitude and belief questions using confirmatory factor analysis. We then examined the relationship between these constructs and quitting behaviours using logistic regression. The secondhand smoke (SHS) and countering pro-tobacco influences'(CPTI) constructs followed a dose-response curve with quitting behaviours. Respondents who rated high on the SHS construct were about 70% more likely to have made a recent quit attempt in the last 12 months and about 100% more likely to intend to quit in the next 6 months than respondents who rated low on the SHS construct. For CPTI, respondents who rated high on this construct were 67% more likely to have made a recent quit attempt in the last 12 months and 62% more likely to have intentions to quit in the next 6 months than respondents who rated low on the CPTI construct. Social norm change constructs represent CTCP's priorities and are strongly related to desired individual behaviour outcomes. This analysis provides strong support for the framework underlying CTCP--namely, that changing social norms affects behaviour change at the individual level through changing population-level smoking-related behaviours.

  8. A new Newton-like method for solving nonlinear equations.

    PubMed

    Saheya, B; Chen, Guo-Qing; Sui, Yun-Kang; Wu, Cai-Ying

    2016-01-01

    This paper presents an iterative scheme for solving nonline ar equations. We establish a new rational approximation model with linear numerator and denominator which has generalizes the local linear model. We then employ the new approximation for nonlinear equations and propose an improved Newton's method to solve it. The new method revises the Jacobian matrix by a rank one matrix each iteration and obtains the quadratic convergence property. The numerical performance and comparison show that the proposed method is efficient.

  9. Sociometric network structure and its association with methamphetamine use norms among homeless youth.

    PubMed

    Barman-Adhikari, Anamika; Begun, Stephanie; Rice, Eric; Yoshioka-Maxwell, Amanda; Perez-Portillo, Andrea

    2016-07-01

    Homeless youths' social networks are consistently linked with their substance use. Social networks influence behavior through several mechanisms, especially social norms. This study used sociometric analyses to understand whether social norms of drug use behaviors are clustered in network structures and whether these perceived norms (descriptive and injunctive) influence youths' drug use behaviors. An event-based approach was used to delineate boundaries of the two sociometric networks of homeless youth, one in Los Angeles, CA (n = 160) and the other in Santa Monica, CA (n = 130). Network characteristics included centrality (i.e., popularity) and cohesiveness (location in dense subnetworks). The primary outcome was recent methamphetamine use. Results revealed that both descriptive and injunctive norms influenced methamphetamine use. Network cohesion was found to be associated with perception of both descriptive and injunctive norms in both networks, however in opposite directions. Network interventions therefore might be effective if designed to capitalize on social influence that naturally occurs in cohesive parts of networks. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. A note on large gauge transformations in double field theory

    DOE PAGES

    Naseer, Usman

    2015-06-03

    Here, we give a detailed proof of the conjecture by Hohm and Zwiebach in double field theory. Our result implies that their proposal for large gauge transformations in terms of the Jacobian matrix for coordinate transformations is, as required, equivalent to the standard exponential map associated with the generalized Lie derivative along a suitable parameter.

  11. Masculinity and HIV: Dimensions of Masculine Norms that Contribute to Men's HIV-Related Sexual Behaviors.

    PubMed

    Fleming, Paul J; DiClemente, Ralph J; Barrington, Clare

    2016-04-01

    Numerous studies have documented a relationship between masculine norms and men's HIV-related sexual behaviors, but intervening upon this relationship requires a nuanced understanding of the specific aspects of masculine norms that shape men's sexual behaviors. We integrate theories on masculinities with empirical HIV research to identify specific dimensions of masculine norms that influence men's HIV-related sexual behaviors. We identify three major dimensions of masculine norms that shape men's sexual behavior: (1) uncontrollable male sex drive, (2) capacity to perform sexually, and (3) power over others. While the existing literature does help explain the relationship between masculine norms and men's sexual behaviors several gaps remain including: a recognition of context-specific masculinities, an interrogation of the positive influences of masculinity, adoption of an intersectional approach, assessment of changes in norms and behaviors over time, and rigorous evaluations of gender-transformative approaches. Addressing these gaps in future research may optimize prevention efforts.

  12. Linking social norms to efficient conservation investment in payments for ecosystem services

    PubMed Central

    Chen, Xiaodong; Lupi, Frank; He, Guangming; Liu, Jianguo

    2009-01-01

    An increasing amount of investment has been devoted to protecting and restoring ecosystem services worldwide. The efficiency of conservation investments, including payments for ecosystem services (PES), has been found to be affected by biological, political, economic, demographic, and social factors, but little is known about the effects of social norms at the neighborhood level. As a first attempt to quantify the effects of social norms, we studied the effects of a series of possible factors on people's intentions of maintaining forest on their Grain-to-Green Program (GTGP) land plots if the program ends. GTGP is one of the world's largest PES programs and plays an important role in global conservation efforts. Our study was conducted in China's Wolong Nature Reserve, home to the world-famous endangered giant pandas and >4,500 farmers. We found that, in addition to conservation payment amounts and program duration, social norms at the neighborhood level had significant impacts on program re-enrollment, suggesting that social norms can be used to leverage participation to enhance the sustainability of conservation benefits from PES programs. Moreover, our results demonstrate that economic and demographic trends also have profound implications for sustainable conservation. Thus, social norms should be incorporated with economic and demographic trends for efficient conservation investments. PMID:19564610

  13. Linking social norms to efficient conservation investment in payments for ecosystem services.

    PubMed

    Chen, Xiaodong; Lupi, Frank; He, Guangming; Liu, Jianguo

    2009-07-14

    An increasing amount of investment has been devoted to protecting and restoring ecosystem services worldwide. The efficiency of conservation investments, including payments for ecosystem services (PES), has been found to be affected by biological, political, economic, demographic, and social factors, but little is known about the effects of social norms at the neighborhood level. As a first attempt to quantify the effects of social norms, we studied the effects of a series of possible factors on people's intentions of maintaining forest on their Grain-to-Green Program (GTGP) land plots if the program ends. GTGP is one of the world's largest PES programs and plays an important role in global conservation efforts. Our study was conducted in China's Wolong Nature Reserve, home to the world-famous endangered giant pandas and >4,500 farmers. We found that, in addition to conservation payment amounts and program duration, social norms at the neighborhood level had significant impacts on program re-enrollment, suggesting that social norms can be used to leverage participation to enhance the sustainability of conservation benefits from PES programs. Moreover, our results demonstrate that economic and demographic trends also have profound implications for sustainable conservation. Thus, social norms should be incorporated with economic and demographic trends for efficient conservation investments.

  14. COMPARED TO WHAT? EARLY BRAIN OVERGROWTH IN AUTISM AND THE PERILS OF POPULATION NORMS

    PubMed Central

    Raznahan, Armin; Wallace, Gregory L; Antezana, Ligia; Greenstein, Dede; Lenroot, Rhoshel; Thurm, Audrey; Gozzi, Marta; Spence, Sarah; Martin, Alex; Swedo, Susan E; Giedd, Jay N

    2013-01-01

    Background Early brain overgrowth (EBO) in autism spectrum disorder (ASD) is amongst the best-replicated biological associations in psychiatry. Most positive reports have compared head circumference (HC) in ASD (an excellent proxy for early brain size) with well-known reference norms. We sought to reappraise evidence for the EBO hypothesis given (i) the recent proliferation of longitudinal HC studies in ASD, and (ii) emerging reports that several of the reference norms used to define EBO in ASD may be biased towards detecting HC overgrowth in contemporary samples of healthy children. Methods (1)Systematic review of all published HC studies in children with ASD. (2)Comparison of 330 longitudinally gathered HC measures between birth and 18 months from male children with autism(n=35) and typically developing controls(n=22). Results In systematic review, comparisons with locally recruited controls were significantly less likely to identify EBO in ASD than norm-based studies(p<0.006). Through systematic review and analysis of new data we replicate seminal reports of EBO in ASD relative to classical HC norms, but show that this overgrowth relative to norms is mimicked by patterns of HC growth age in a large contemporary community-based sample of US children(n~75,000). Controlling for known HC norm biases leaves inconsistent support for a subtle, later-emerging and sub-group specific pattern of EBO in clinically-ascertained ASD vs. community controls. Conclusions The best-replicated aspects of EBO reflect generalizable HC norm biases rather than disease-specific biomarkers. The potential HC norm biases we detail are not specific to ASD research, but apply throughout clinical and academic medicine. PMID:23706681

  15. On epicardial potential reconstruction using regularization schemes with the L1-norm data term.

    PubMed

    Shou, Guofa; Xia, Ling; Liu, Feng; Jiang, Mingfeng; Crozier, Stuart

    2011-01-07

    The electrocardiographic (ECG) inverse problem is ill-posed and usually solved by regularization schemes. These regularization methods, such as the Tikhonov method, are often based on the L2-norm data and constraint terms. However, L2-norm-based methods inherently provide smoothed inverse solutions that are sensitive to measurement errors, and also lack the capability of localizing and distinguishing multiple proximal cardiac electrical sources. This paper presents alternative regularization schemes employing the L1-norm data term for the reconstruction of epicardial potentials (EPs) from measured body surface potentials (BSPs). During numerical implementation, the iteratively reweighted norm algorithm was applied to solve the L1-norm-related schemes, and measurement noises were considered in the BSP data. The proposed L1-norm data term-based regularization schemes (with L1 and L2 penalty terms of the normal derivative constraint (labelled as L1TV and L1L2)) were compared with the L2-norm data terms (Tikhonov with zero-order and normal derivative constraints, labelled as ZOT and FOT, and the total variation method labelled as L2TV). The studies demonstrated that, with averaged measurement noise, the inverse solutions provided by the L1L2 and FOT algorithms have less relative error values. However, when larger noise occurred in some electrodes (for example, signal lost during measurement), the L1TV and L1L2 methods can obtain more accurate EPs in a robust manner. Therefore the L1-norm data term-based solutions are generally less perturbed by measurement noises, suggesting that the new regularization scheme is promising for providing practical ECG inverse solutions.

  16. Uranium Mining and Norm in North America-Some Perspectives on Occupational Radiation Exposure.

    PubMed

    Brown, Steven H; Chambers, Douglas B

    2017-07-01

    All soils and rocks contain naturally occurring radioactive materials (NORM). Many ores and raw materials contain relatively elevated levels of natural radionuclides, and processing such materials can further increase the concentrations of naturally occurring radionuclides. In the U.S., these materials are sometimes referred to as technologically-enhanced naturally occurring radioactive materials (TENORM). Examples of NORM minerals include uranium ores, monazite (a source of rare earth minerals), and phosphate rock used to produce phosphate fertilizer. The processing of these materials has the potential to result in above-background radiation exposure to workers. Following a brief review of the sources and potential for worker exposure from NORM in these varied industries, this paper will then present an overview of uranium mining and recovery in North America, including discussion on the mining methods currently being used for both conventional (underground, open pit) and in situ leach (ISL), also referred to as In Situ Recovery (ISR), and the production of NORM materials and wastes associated with these uranium recovery methods. The radiological composition of the NORM products and wastes produced and recent data on radiological exposures received by workers in the North American uranium recovery industry are then described. The paper also identifies the responsible government agencies in the U.S. and Canada assigned the authority to regulate and control occupational exposure from these NORM materials.

  17. Effects of perceived descriptive norms on corrupt intention: The mediating role of moral disengagement.

    PubMed

    Zhao, Huanhuan; Zhang, Heyun; Xu, Yan

    2017-01-31

    The present study attempts to examine the effect of perceived descriptive norms on corrupt intention (e.g., bribe-taking intention) and then further explore the psychological mechanism underlying this effect. Based on social cognitive theory, we established a mediation model in which moral disengagement partially mediated the link between perceived descriptive norms and corrupt intention. In Study 1, participants (N = 690) completed a series of questionnaires, and the results demonstrated that, while perceived descriptive norms were positively associated with corrupt intention, it was partially mediated by moral disengagement. In Study 2, we conducted a priming experiment (N = 161) to test the causal relationship and psychological mechanism between perceived descriptive norms and corrupt intention. The results revealed that perceived descriptive norms triggered the propensity of individuals to morally disengage, which in turn, partially increased their corrupt intention. This study not only extends previous research by providing evidence that moral disengagement may be one of the reasons why perceived descriptive norms facilitate corrupt intention, but also suggests that reshaping normative beliefs and preventing the moral disengagement of individuals may be the effective ways to curb corrupt behaviours. © 2017 International Union of Psychological Science.

  18. Learning the inverse kinetics of an octopus-like manipulator in three-dimensional space.

    PubMed

    Giorelli, M; Renda, F; Calisti, M; Arienti, A; Ferri, G; Laschi, C

    2015-05-13

    This work addresses the inverse kinematics problem of a bioinspired octopus-like manipulator moving in three-dimensional space. The bioinspired manipulator has a conical soft structure that confers the ability of twirling around objects as a real octopus arm does. Despite the simple design, the soft conical shape manipulator driven by cables is described by nonlinear differential equations, which are difficult to solve analytically. Since exact solutions of the equations are not available, the Jacobian matrix cannot be calculated analytically and the classical iterative methods cannot be used. To overcome the intrinsic problems of methods based on the Jacobian matrix, this paper proposes a neural network learning the inverse kinematics of a soft octopus-like manipulator driven by cables. After the learning phase, a feed-forward neural network is able to represent the relation between manipulator tip positions and forces applied to the cables. Experimental results show that a desired tip position can be achieved in a short time, since heavy computations are avoided, with a degree of accuracy of 8% relative average error with respect to the total arm length.

  19. Kinematics of an in-parallel actuated manipulator based on the Stewart platform mechanism

    NASA Technical Reports Server (NTRS)

    Williams, Robert L., II

    1992-01-01

    This paper presents kinematic equations and solutions for an in-parallel actuated robotic mechanism based on Stewart's platform. These equations are required for inverse position and resolved rate (inverse velocity) platform control. NASA LaRC has a Vehicle Emulator System (VES) platform designed by MIT which is based on Stewart's platform. The inverse position solution is straight-forward and computationally inexpensive. Given the desired position and orientation of the moving platform with respect to the base, the lengths of the prismatic leg actuators are calculated. The forward position solution is more complicated and theoretically has 16 solutions. The position and orientation of the moving platform with respect to the base is calculated given the leg actuator lengths. Two methods are pursued in this paper to solve this problem. The resolved rate (inverse velocity) solution is derived. Given the desired Cartesian velocity of the end-effector, the required leg actuator rates are calculated. The Newton-Raphson Jacobian matrix resulting from the second forward position kinematics solution is a modified inverse Jacobian matrix. Examples and simulations are given for the VES.

  20. Analysis and design of a six-degree-of-freedom Stewart platform-based robotic wrist

    NASA Technical Reports Server (NTRS)

    Nguyen, Charles C.; Antrazi, Sami; Zhou, Zhen-Lei

    1991-01-01

    The kinematic analysis and implementation of a six degree of freedom robotic wrist which is mounted to a general open-kinetic chain manipulator to serve as a restbed for studying precision robotic assembly in space is discussed. The wrist design is based on the Stewart Platform mechanism and consists mainly of two platforms and six linear actuators driven by DC motors. Position feedback is achieved by linear displacement transducers mounted along the actuators and force feedback is obtained by a 6 degree of freedom force sensor mounted between the gripper and the payload platform. The robot wrist inverse kinematics which computes the required actuator lengths corresponding to Cartesian variables has a closed-form solution. The forward kinematics is solved iteratively using the Newton-Ralphson method which simultaneously provides a modified Jacobian Matrix which relates length velocities to Cartesian translational velocities and time rates of change of roll-pitch-yaw angles. Results of computer simulation conducted to evaluate the efficiency of the forward kinematics and Modified Jacobian Matrix are discussed.