271 research outputs found

    Robust Error Estimation Based on Factor-Graph Models for Non-Line-of-Sight Localization

    Get PDF
    This paper presents a method to estimate the covariances of the inputs in a factor-graph formulation for localization under non-line-of-sight conditions. A general solution based on covariance estimation and M-estimators in linear regression problems, is presented that is shown to give unbiased estimators of multiple variances and are robust against outliers. An iteratively re-weighted least squares algorithm is proposed to jointly compute the proposed variance estimators and the state estimates for the nonlinear factor graph optimization. The efficacy of the method is illustrated in a simulation study using a robot localization problem under various process and measurement models and measurement outlier scenarios. A case study involving a Global Positioning System based localization in an urban environment and data containing multipath problems demonstrates the application of the proposed technique

    Volume CVI, Number 10, January 13, 1989

    Get PDF
    WOS: 000188054500005Two subspecies of mistletoe (Viscum album L. ssp. album and ssp. abietis) growing on lime and pine trees, respectively, were investigated for the monosaccharides and polyols by GC-MS spectrometry. Arabinose, xylose, glucose, galactose, mannose, xylitol and inositol were determined in methanol extracts following the acidic hydrolysis. Sugar contents of the leaves were expressed as percentage on dry weight. Xylose content was the same (1.5%) in each species, whereas the other saccharides varied. V. album ssp. abietis (collected from pine trees) were found containing significantly higher percentage of glucose (29.0%) and galactose (44.0%) than V. album ssp. album (collected from lime trees) (9.0% and 17.0%, respectively). In contrast, mannose, arabinose and sugar alcohol percentages were higher in ssp. album. Mannose content was 3.5% for ssp. album whereas 1.0% for ssp. abietis. 3.0% arabinose were determined in the former and 2.0% in the latter. Xylitol and inositol percentages were 8.0% and 58.0% for ssp. album and 1.5% and 21.0% for ssp. abietis, respectively. These results indicate that saccharide composition of mistletoes depends upon the subspecies of the plant and the host tree

    Effective-mass Klein-Gordon Equation for non-PT/non-Hermitian Generalized Morse Potential

    Full text link
    The one-dimensional effective-mass Klein-Gordon equation for the real, and non-\textrm{PT}-symmetric/non-Hermitian generalized Morse potential is solved by taking a series expansion for the wave function. The energy eigenvalues, and the corresponding eigenfunctions are obtained. They are also calculated for the constant mass case.Comment: 14 page

    New exact solution of the one dimensional Dirac Equation for the Woods-Saxon potential within the effective mass case

    Full text link
    We study the one-dimensional Dirac equation in the framework of a position dependent mass under the action of a Woods-Saxon external potential. We find that constraining appropriately the mass function it is possible to obtain a solution of the problem in terms of the hypergeometric function. The mass function for which this turns out to be possible is continuous. In particular we study the scattering problem and derive exact expressions for the reflection and transmission coefficients which are compared to those of the constant mass case. For the very same mass function the bound state problem is also solved, providing a transcendental equation for the energy eigenvalues which is solved numerically.Comment: Version to match the one which has been accepted for publication by J. Phys. A: Math. Theor. Added one figure, several comments and few references. (24 pages and 7 figures

    Scattering of Woods-Saxon Potential in Schrodinger Equation

    Full text link
    The scattering solutions of the one-dimensional Schrodinger equation for the Woods-Saxon potential are obtained within the position-dependent mass formalism. The wave functions, transmission and reflection coefficients are calculated in terms of Heun's function. These results are also studied for the constant mass case in detail.Comment: 14 page

    The Eyes Have It: Measuring Spatial Orientation in Virtual Worlds to Explain Gender Differences in Real Ones

    Get PDF
    Here, we explore how 3D, networked virtual worlds - in particular Second Life, which enables users to create and modify their own environments - can act as a kind of \u27virtual\u27 laboratory for studying gender difference. By tracking users\u27 eye movements as they navigate a virtual rendition of the Morris Water Maze (the \u27gold standard\u27 for measuring gender difference in spatial orientation, navigation and mobility), this work constitutes an empirical basis for claims that we have attempted to make in the context of ethnographic work with female and male video game players, both novice and expert: that mastery of, and the ability to competently navigate through space, both real and virtual, is as much (if not more) learned and acquired, as it inheres in the bodies and brains of differently-sexed subjects

    Analytical Solutions of Klein-Gordon Equation with Position-Dependent Mass for q-Parameter Poschl-Teller potential

    Get PDF
    The energy eigenvalues and the corresponding eigenfunctions of the one-dimensional Klein-Gordon equation with q-parameter Poschl-Teller potential are analytically obtained within the position-dependent mass formalism. The parametric generalization of the Nikiforov-Uvarov method is used in the calculations by choosing a mass distribution.Comment: 10 page

    A relational view of environmental performance: What role do environmental collaboration and cross-functional alignment play?

    Get PDF
    Despite extensive research into the role played by social capital and relational capability in attaining interorganizational advantage, the way in which these resources matter for environmental performance has received scant attention. We investigate how firms' social capital and relational capability influence their environmental performance, by analyzing the mediating role of environmental collaboration and the moderating role of crossfunctional alignment. Based on an analysis of dual responses from 270 Turkish firms, we find that environmental collaboration mediates the impact of social capital and relational capability on environmental performance. We also find that alignment between marketing and supply chain management functions strengthens the effects of relational capability and environmental collaboration on environmental performance. Our study suggests that both environmental collaboration and cross-functional alignment are necessary if the true value of social capital and relational capability for environmental performance is to be realized.Q2WOS:0004575123000042-s2.0-8505614829
    corecore