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Sample records for determinantal point processes

  1. Statistical aspects of determinantal point processes

    DEFF Research Database (Denmark)

    Lavancier, Frédéric; Møller, Jesper; Rubak, Ege

    The statistical aspects of determinantal point processes (DPPs) seem largely unexplored. We review the appealing properties of DDPs, demonstrate that they are useful models for repulsiveness, detail a simulation procedure, and provide freely available software for simulation and statistical infer...

  2. Statistical aspects of determinantal point processes

    DEFF Research Database (Denmark)

    Lavancier, Frédéric; Møller, Jesper; Rubak, Ege Holger

    The statistical aspects of determinantal point processes (DPPs) seem largely unexplored. We review the appealing properties of DDPs, demonstrate that they are useful models for repulsiveness, detail a simulation procedure, and provide freely available software for simulation and statistical...... inference. We pay special attention to stationary DPPs, where we give a simple condition ensuring their existence, construct parametric models, describe how they can be well approximated so that the likelihood can be evaluated and realizations can be simulated, and discuss how statistical inference...

  3. Determinantal point process models on the sphere

    DEFF Research Database (Denmark)

    Møller, Jesper; Nielsen, Morten; Porcu, Emilio

    defined on Sd × Sd . We review the appealing properties of such processes, including their specific moment properties, density expressions and simulation procedures. Particularly, we characterize and construct isotropic DPPs models on Sd , where it becomes essential to specify the eigenvalues......We consider determinantal point processes on the d-dimensional unit sphere Sd . These are finite point processes exhibiting repulsiveness and with moment properties determined by a certain determinant whose entries are specified by a so-called kernel which we assume is a complex covariance function...... and eigenfunctions in a spectral representation for the kernel, and we figure out how repulsive isotropic DPPs can be. Moreover, we discuss the shortcomings of adapting existing models for isotropic covariance functions and consider strategies for developing new models, including a useful spectral approach....

  4. Discrete Approximations of Determinantal Point Processes on Continuous Spaces: Tree Representations and Tail Triviality

    Science.gov (United States)

    Osada, Hirofumi; Osada, Shota

    2018-01-01

    We prove tail triviality of determinantal point processes μ on continuous spaces. Tail triviality has been proved for such processes only on discrete spaces, and hence we have generalized the result to continuous spaces. To do this, we construct tree representations, that is, discrete approximations of determinantal point processes enjoying a determinantal structure. There are many interesting examples of determinantal point processes on continuous spaces such as zero points of the hyperbolic Gaussian analytic function with Bergman kernel, and the thermodynamic limit of eigenvalues of Gaussian random matrices for Sine_2 , Airy_2 , Bessel_2 , and Ginibre point processes. Our main theorem proves all these point processes are tail trivial.

  5. Elliptic Determinantal Processes and Elliptic Dyson Models

    Science.gov (United States)

    Katori, Makoto

    2017-10-01

    We introduce seven families of stochastic systems of interacting particles in one-dimension corresponding to the seven families of irreducible reduced affine root systems. We prove that they are determinantal in the sense that all spatio-temporal correlation functions are given by determinants controlled by a single function called the spatio-temporal correlation kernel. For the four families {A}_{N-1}, {B}_N, {C}_N and {D}_N, we identify the systems of stochastic differential equations solved by these determinantal processes, which will be regarded as the elliptic extensions of the Dyson model. Here we use the notion of martingales in probability theory and the elliptic determinant evaluations of the Macdonald denominators of irreducible reduced affine root systems given by Rosengren and Schlosser.

  6. Poisson branching point processes

    International Nuclear Information System (INIS)

    Matsuo, K.; Teich, M.C.; Saleh, B.E.A.

    1984-01-01

    We investigate the statistical properties of a special branching point process. The initial process is assumed to be a homogeneous Poisson point process (HPP). The initiating events at each branching stage are carried forward to the following stage. In addition, each initiating event independently contributes a nonstationary Poisson point process (whose rate is a specified function) located at that point. The additional contributions from all points of a given stage constitute a doubly stochastic Poisson point process (DSPP) whose rate is a filtered version of the initiating point process at that stage. The process studied is a generalization of a Poisson branching process in which random time delays are permitted in the generation of events. Particular attention is given to the limit in which the number of branching stages is infinite while the average number of added events per event of the previous stage is infinitesimal. In the special case when the branching is instantaneous this limit of continuous branching corresponds to the well-known Yule--Furry process with an initial Poisson population. The Poisson branching point process provides a useful description for many problems in various scientific disciplines, such as the behavior of electron multipliers, neutron chain reactions, and cosmic ray showers

  7. Thinning spatial point processes into Poisson processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Schoenberg, Frederic Paik

    2010-01-01

    are identified, and where we simulate backwards and forwards in order to obtain the thinned process. In the case of a Cox process, a simple independent thinning technique is proposed. In both cases, the thinning results in a Poisson process if and only if the true Papangelou conditional intensity is used, and......In this paper we describe methods for randomly thinning certain classes of spatial point processes. In the case of a Markov point process, the proposed method involves a dependent thinning of a spatial birth-and-death process, where clans of ancestors associated with the original points......, thus, can be used as a graphical exploratory tool for inspecting the goodness-of-fit of a spatial point process model. Several examples, including clustered and inhibitive point processes, are considered....

  8. Thinning spatial point processes into Poisson processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Schoenberg, Frederic Paik

    , and where one simulates backwards and forwards in order to obtain the thinned process. In the case of a Cox process, a simple independent thinning technique is proposed. In both cases, the thinning results in a Poisson process if and only if the true Papangelou conditional intensity is used, and thus can......This paper describes methods for randomly thinning certain classes of spatial point processes. In the case of a Markov point process, the proposed method involves a dependent thinning of a spatial birth-and-death process, where clans of ancestors associated with the original points are identified...... be used as a diagnostic for assessing the goodness-of-fit of a spatial point process model. Several examples, including clustered and inhibitive point processes, are considered....

  9. Detecting determinism from point processes.

    Science.gov (United States)

    Andrzejak, Ralph G; Mormann, Florian; Kreuz, Thomas

    2014-12-01

    The detection of a nonrandom structure from experimental data can be crucial for the classification, understanding, and interpretation of the generating process. We here introduce a rank-based nonlinear predictability score to detect determinism from point process data. Thanks to its modular nature, this approach can be adapted to whatever signature in the data one considers indicative of deterministic structure. After validating our approach using point process signals from deterministic and stochastic model dynamics, we show an application to neuronal spike trains recorded in the brain of an epilepsy patient. While we illustrate our approach in the context of temporal point processes, it can be readily applied to spatial point processes as well.

  10. Fixed-point signal processing

    CERN Document Server

    Padgett, Wayne T

    2009-01-01

    This book is intended to fill the gap between the ""ideal precision"" digital signal processing (DSP) that is widely taught, and the limited precision implementation skills that are commonly required in fixed-point processors and field programmable gate arrays (FPGAs). These skills are often neglected at the university level, particularly for undergraduates. We have attempted to create a resource both for a DSP elective course and for the practicing engineer with a need to understand fixed-point implementation. Although we assume a background in DSP, Chapter 2 contains a review of basic theory

  11. Processing Terrain Point Cloud Data

    KAUST Repository

    DeVore, Ronald

    2013-01-10

    Terrain point cloud data are typically acquired through some form of Light Detection And Ranging sensing. They form a rich resource that is important in a variety of applications including navigation, line of sight, and terrain visualization. Processing terrain data has not received the attention of other forms of surface reconstruction or of image processing. The goal of terrain data processing is to convert the point cloud into a succinct representation system that is amenable to the various application demands. The present paper presents a platform for terrain processing built on the following principles: (i) measuring distortion in the Hausdorff metric, which we argue is a good match for the application demands, (ii) a multiscale representation based on tree approximation using local polynomial fitting. The basic elements held in the nodes of the tree can be efficiently encoded, transmitted, visualized, and utilized for the various target applications. Several challenges emerge because of the variable resolution of the data, missing data, occlusions, and noise. Techniques for identifying and handling these challenges are developed. © 2013 Society for Industrial and Applied Mathematics.

  12. TD-S-HF single determinantal reaction theory and the description of many-body processes, including fission

    International Nuclear Information System (INIS)

    Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.; Kan, K.K.

    1979-01-01

    The restrictions implied for the time dependent many-body reaction theory by the (TDHF) single determinantal assumption are explored by constructive analysis. A restructured TD-S-HF reaction theory is modelled, not after the initial-value form of the Schroedinger reaction theory, but after the (fully equivalent) S-matrix form, under the conditions that only self-consistent TDHF solutions occur in the theory, every wave function obeys the fundamental statistical interpretation of quantum mechanics, and the theory reduces to the exact Schroedinger theory for exact solutions which are single determinantal. All of these conditions can be accomodated provided that the theory is interpreted on a time-averaged basis, i.e., physical constants of the Schroedinger theory which are time-dependent in the TDHF theory, are interpreted in TD-S-HF in terms of their time averaged values. The resulting reaction theory, although formulated heuristically, prescribes a well defined and unambiguous calculational program which, although somewhat more demanding technically than the conventional initial-value TDHF method, is nevertheless more consonant with first principles, structurally and mechanistically. For its physical predictions do not depend upon the precise location of the distant measuring apparatus, and are in no way influenced by the spurious cross channel correlations which arise whenever the description of many reaction channels is imposed upon one single-determinantal solution. For nuclear structure physics, the TDHF-eigenfunctions provide the first plausible description of exact eigenstates in the time-dependent framework; moreover, they are unencumbered by any restriction to small amplitudes. 14 references

  13. Processing Terrain Point Cloud Data

    KAUST Repository

    DeVore, Ronald; Petrova, Guergana; Hielsberg, Matthew; Owens, Luke; Clack, Billy; Sood, Alok

    2013-01-01

    Terrain point cloud data are typically acquired through some form of Light Detection And Ranging sensing. They form a rich resource that is important in a variety of applications including navigation, line of sight, and terrain visualization

  14. Inhomogeneous Markov point processes by transformation

    DEFF Research Database (Denmark)

    Jensen, Eva B. Vedel; Nielsen, Linda Stougaard

    2000-01-01

    We construct parametrized models for point processes, allowing for both inhomogeneity and interaction. The inhomogeneity is obtained by applying parametrized transformations to homogeneous Markov point processes. An interesting model class, which can be constructed by this transformation approach......, is that of exponential inhomogeneous Markov point processes. Statistical inference For such processes is discussed in some detail....

  15. Testing Local Independence between Two Point Processes

    DEFF Research Database (Denmark)

    Allard, Denis; Brix, Anders; Chadæuf, Joël

    2001-01-01

    Independence test, Inhomogeneous point processes, Local test, Monte Carlo, Nonstationary, Rotations, Spatial pattern, Tiger bush......Independence test, Inhomogeneous point processes, Local test, Monte Carlo, Nonstationary, Rotations, Spatial pattern, Tiger bush...

  16. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper

    We define residuals for point process models fitted to spatial point pattern data, and propose diagnostic plots based on these residuals. The techniques apply to any Gibbs point process model, which may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Ou...... or covariate effects. Q-Q plots of the residuals are effective in diagnosing interpoint interaction. Some existing ad hoc statistics of point patterns (quadrat counts, scan statistic, kernel smoothed intensity, Berman's diagnostic) are recovered as special cases....

  17. Lévy based Cox point processes

    DEFF Research Database (Denmark)

    Hellmund, Gunnar; Prokesová, Michaela; Jensen, Eva Bjørn Vedel

    2008-01-01

    In this paper we introduce Lévy-driven Cox point processes (LCPs) as Cox point processes with driving intensity function Λ defined by a kernel smoothing of a Lévy basis (an independently scattered, infinitely divisible random measure). We also consider log Lévy-driven Cox point processes (LLCPs......) with Λ equal to the exponential of such a kernel smoothing. Special cases are shot noise Cox processes, log Gaussian Cox processes, and log shot noise Cox processes. We study the theoretical properties of Lévy-based Cox processes, including moment properties described by nth-order product densities...

  18. State estimation for temporal point processes

    NARCIS (Netherlands)

    van Lieshout, Maria Nicolette Margaretha

    2015-01-01

    This paper is concerned with combined inference for point processes on the real line observed in a broken interval. For such processes, the classic history-based approach cannot be used. Instead, we adapt tools from sequential spatial point processes. For a range of models, the marginal and

  19. Bayesian analysis of Markov point processes

    DEFF Research Database (Denmark)

    Berthelsen, Kasper Klitgaard; Møller, Jesper

    2006-01-01

    Recently Møller, Pettitt, Berthelsen and Reeves introduced a new MCMC methodology for drawing samples from a posterior distribution when the likelihood function is only specified up to a normalising constant. We illustrate the method in the setting of Bayesian inference for Markov point processes...... a partially ordered Markov point process as the auxiliary variable. As the method requires simulation from the "unknown" likelihood, perfect simulation algorithms for spatial point processes become useful....

  20. Poisson point processes imaging, tracking, and sensing

    CERN Document Server

    Streit, Roy L

    2010-01-01

    This overview of non-homogeneous and multidimensional Poisson point processes and their applications features mathematical tools and applications from emission- and transmission-computed tomography to multiple target tracking and distributed sensor detection.

  1. Modeling fixation locations using spatial point processes.

    Science.gov (United States)

    Barthelmé, Simon; Trukenbrod, Hans; Engbert, Ralf; Wichmann, Felix

    2013-10-01

    Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first approximation, a set of fixations can be viewed as a set of points in space; this implies that fixations are spatial data and that the analysis of fixation locations can be beneficially thought of as a spatial statistics problem. We argue that thinking of fixation locations as arising from point processes is a very fruitful framework for eye-movement data, helping turn qualitative questions into quantitative ones. We provide a tutorial introduction to some of the main ideas of the field of spatial statistics, focusing especially on spatial Poisson processes. We show how point processes help relate image properties to fixation locations. In particular we show how point processes naturally express the idea that image features' predictability for fixations may vary from one image to another. We review other methods of analysis used in the literature, show how they relate to point process theory, and argue that thinking in terms of point processes substantially extends the range of analyses that can be performed and clarify their interpretation.

  2. Fingerprint Analysis with Marked Point Processes

    DEFF Research Database (Denmark)

    Forbes, Peter G. M.; Lauritzen, Steffen; Møller, Jesper

    We present a framework for fingerprint matching based on marked point process models. An efficient Monte Carlo algorithm is developed to calculate the marginal likelihood ratio for the hypothesis that two observed prints originate from the same finger against the hypothesis that they originate from...... different fingers. Our model achieves good performance on an NIST-FBI fingerprint database of 258 matched fingerprint pairs....

  3. Modern Statistics for Spatial Point Processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Waagepetersen, Rasmus

    2007-01-01

    We summarize and discuss the current state of spatial point process theory and directions for future research, making an analogy with generalized linear models and random effect models, and illustrating the theory with various examples of applications. In particular, we consider Poisson, Gibbs...

  4. Modern statistics for spatial point processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Waagepetersen, Rasmus

    We summarize and discuss the current state of spatial point process theory and directions for future research, making an analogy with generalized linear models and random effect models, and illustrating the theory with various examples of applications. In particular, we consider Poisson, Gibbs...

  5. Extreme values, regular variation and point processes

    CERN Document Server

    Resnick, Sidney I

    1987-01-01

    Extremes Values, Regular Variation and Point Processes is a readable and efficient account of the fundamental mathematical and stochastic process techniques needed to study the behavior of extreme values of phenomena based on independent and identically distributed random variables and vectors It presents a coherent treatment of the distributional and sample path fundamental properties of extremes and records It emphasizes the core primacy of three topics necessary for understanding extremes the analytical theory of regularly varying functions; the probabilistic theory of point processes and random measures; and the link to asymptotic distribution approximations provided by the theory of weak convergence of probability measures in metric spaces The book is self-contained and requires an introductory measure-theoretic course in probability as a prerequisite Almost all sections have an extensive list of exercises which extend developments in the text, offer alternate approaches, test mastery and provide for enj...

  6. Estimating Function Approaches for Spatial Point Processes

    Science.gov (United States)

    Deng, Chong

    Spatial point pattern data consist of locations of events that are often of interest in biological and ecological studies. Such data are commonly viewed as a realization from a stochastic process called spatial point process. To fit a parametric spatial point process model to such data, likelihood-based methods have been widely studied. However, while maximum likelihood estimation is often too computationally intensive for Cox and cluster processes, pairwise likelihood methods such as composite likelihood, Palm likelihood usually suffer from the loss of information due to the ignorance of correlation among pairs. For many types of correlated data other than spatial point processes, when likelihood-based approaches are not desirable, estimating functions have been widely used for model fitting. In this dissertation, we explore the estimating function approaches for fitting spatial point process models. These approaches, which are based on the asymptotic optimal estimating function theories, can be used to incorporate the correlation among data and yield more efficient estimators. We conducted a series of studies to demonstrate that these estmating function approaches are good alternatives to balance the trade-off between computation complexity and estimating efficiency. First, we propose a new estimating procedure that improves the efficiency of pairwise composite likelihood method in estimating clustering parameters. Our approach combines estimating functions derived from pairwise composite likeli-hood estimation and estimating functions that account for correlations among the pairwise contributions. Our method can be used to fit a variety of parametric spatial point process models and can yield more efficient estimators for the clustering parameters than pairwise composite likelihood estimation. We demonstrate its efficacy through a simulation study and an application to the longleaf pine data. Second, we further explore the quasi-likelihood approach on fitting

  7. Point cloud processing for smart systems

    Directory of Open Access Journals (Sweden)

    Jaromír Landa

    2013-01-01

    Full Text Available High population as well as the economical tension emphasises the necessity of effective city management – from land use planning to urban green maintenance. The management effectiveness is based on precise knowledge of the city environment. Point clouds generated by mobile and terrestrial laser scanners provide precise data about objects in the scanner vicinity. From these data pieces the state of the roads, buildings, trees and other objects important for this decision-making process can be obtained. Generally, they can support the idea of “smart” or at least “smarter” cities.Unfortunately the point clouds do not provide this type of information automatically. It has to be extracted. This extraction is done by expert personnel or by object recognition software. As the point clouds can represent large areas (streets or even cities, usage of expert personnel to identify the required objects can be very time-consuming, therefore cost ineffective. Object recognition software allows us to detect and identify required objects semi-automatically or automatically.The first part of the article reviews and analyses the state of current art point cloud object recognition techniques. The following part presents common formats used for point cloud storage and frequently used software tools for point cloud processing. Further, a method for extraction of geospatial information about detected objects is proposed. Therefore, the method can be used not only to recognize the existence and shape of certain objects, but also to retrieve their geospatial properties. These objects can be later directly used in various GIS systems for further analyses.

  8. Parametric methods for spatial point processes

    DEFF Research Database (Denmark)

    Møller, Jesper

    is studied in Section 4, and Bayesian inference in Section 5. On one hand, as the development in computer technology and computational statistics continues,computationally-intensive simulation-based methods for likelihood inference probably will play a increasing role for statistical analysis of spatial...... inference procedures for parametric spatial point process models. The widespread use of sensible but ad hoc methods based on summary statistics of the kind studied in Chapter 4.3 have through the last two decades been supplied by likelihood based methods for parametric spatial point process models......(This text is submitted for the volume ‘A Handbook of Spatial Statistics' edited by A.E. Gelfand, P. Diggle, M. Fuentes, and P. Guttorp, to be published by Chapmand and Hall/CRC Press, and planned to appear as Chapter 4.4 with the title ‘Parametric methods'.) 1 Introduction This chapter considers...

  9. Transforming spatial point processes into Poisson processes using random superposition

    DEFF Research Database (Denmark)

    Møller, Jesper; Berthelsen, Kasper Klitgaaard

    with a complementary spatial point process Y  to obtain a Poisson process X∪Y  with intensity function β. Underlying this is a bivariate spatial birth-death process (Xt,Yt) which converges towards the distribution of (X,Y). We study the joint distribution of X and Y, and their marginal and conditional distributions....... In particular, we introduce a fast and easy simulation procedure for Y conditional on X. This may be used for model checking: given a model for the Papangelou intensity of the original spatial point process, this model is used to generate the complementary process, and the resulting superposition is a Poisson...... process with intensity function β if and only if the true Papangelou intensity is used. Whether the superposition is actually such a Poisson process can easily be examined using well known results and fast simulation procedures for Poisson processes. We illustrate this approach to model checking...

  10. Some probabilistic properties of fractional point processes

    KAUST Repository

    Garra, Roberto

    2017-05-16

    In this article, the first hitting times of generalized Poisson processes N-f (t), related to Bernstein functions f are studied. For the spacefractional Poisson processes, N alpha (t), t > 0 ( corresponding to f = x alpha), the hitting probabilities P{T-k(alpha) < infinity} are explicitly obtained and analyzed. The processes N-f (t) are time-changed Poisson processes N( H-f (t)) with subordinators H-f (t) and here we study N(Sigma H-n(j= 1)f j (t)) and obtain probabilistic features of these extended counting processes. A section of the paper is devoted to processes of the form N( G(H,v) (t)) where G(H,v) (t) are generalized grey Brownian motions. This involves the theory of time-dependent fractional operators of the McBride form. While the time-fractional Poisson process is a renewal process, we prove that the space-time Poisson process is no longer a renewal process.

  11. A logistic regression estimating function for spatial Gibbs point processes

    DEFF Research Database (Denmark)

    Baddeley, Adrian; Coeurjolly, Jean-François; Rubak, Ege

    We propose a computationally efficient logistic regression estimating function for spatial Gibbs point processes. The sample points for the logistic regression consist of the observed point pattern together with a random pattern of dummy points. The estimating function is closely related to the p......We propose a computationally efficient logistic regression estimating function for spatial Gibbs point processes. The sample points for the logistic regression consist of the observed point pattern together with a random pattern of dummy points. The estimating function is closely related...

  12. Some probabilistic properties of fractional point processes

    KAUST Repository

    Garra, Roberto; Orsingher, Enzo; Scavino, Marco

    2017-01-01

    P{T-k(alpha) < infinity} are explicitly obtained and analyzed. The processes N-f (t) are time-changed Poisson processes N( H-f (t)) with subordinators H-f (t) and here we study N(Sigma H-n(j= 1)f j (t)) and obtain probabilistic features

  13. On statistical analysis of compound point process

    Czech Academy of Sciences Publication Activity Database

    Volf, Petr

    2006-01-01

    Roč. 35, 2-3 (2006), s. 389-396 ISSN 1026-597X R&D Projects: GA ČR(CZ) GA402/04/1294 Institutional research plan: CEZ:AV0Z10750506 Keywords : counting process * compound process * hazard function * Cox -model Subject RIV: BB - Applied Statistics, Operational Research

  14. Intensity-dependent point spread image processing

    International Nuclear Information System (INIS)

    Cornsweet, T.N.; Yellott, J.I.

    1984-01-01

    There is ample anatomical, physiological and psychophysical evidence that the mammilian retina contains networks that mediate interactions among neighboring receptors, resulting in intersecting transformations between input images and their corresponding neural output patterns. The almost universally accepted view is that the principal form of interaction involves lateral inhibition, resulting in an output pattern that is the convolution of the input with a ''Mexican hat'' or difference-of-Gaussians spread function, having a positive center and a negative surround. A closely related process is widely applied in digital image processing, and in photography as ''unsharp masking''. The authors show that a simple and fundamentally different process, involving no inhibitory or subtractive terms can also account for the physiological and psychophysical findings that have been attributed to lateral inhibition. This process also results in a number of fundamental effects that occur in mammalian vision and that would be of considerable significance in robotic vision, but which cannot be explained by lateral inhibitory interaction

  15. Statistical properties of several models of fractional random point processes

    Science.gov (United States)

    Bendjaballah, C.

    2011-08-01

    Statistical properties of several models of fractional random point processes have been analyzed from the counting and time interval statistics points of view. Based on the criterion of the reduced variance, it is seen that such processes exhibit nonclassical properties. The conditions for these processes to be treated as conditional Poisson processes are examined. Numerical simulations illustrate part of the theoretical calculations.

  16. Microbial profile and critical control points during processing of 'robo ...

    African Journals Online (AJOL)

    Microbial profile and critical control points during processing of 'robo' snack from ... the relevant critical control points especially in relation to raw materials and ... to the quality of the various raw ingredients used were the roasting using earthen

  17. Determinanter for produktinnovationssucces

    DEFF Research Database (Denmark)

    Harmsen, Hanne

    1992-01-01

    , which starts with a very informal structure and subsequently increases formalization, seems to favour success. In addition, the importance of independent, cross-functional project gro stressed. 8. Most of the results given are at a very general level, and a more differentiated view, taking into account...... over industries seems to be 35% for consumer products and 25% for industrial products. 4. The most important general determinants of success of a new product can be grouped as follows: characteristics of the market (e.g., intensity of competition, growth), company skills and resources, the product...... be reason to believe that both radical and incremental innovations fare well, whereas new products with a medium degree of innovativeness do less well. 7. The organization of the product development process in the firm is an important factor determining success of the product. A process in various steps...

  18. Point processes and the position distribution of infinite boson systems

    International Nuclear Information System (INIS)

    Fichtner, K.H.; Freudenberg, W.

    1987-01-01

    It is shown that to each locally normal state of a boson system one can associate a point process that can be interpreted as the position distribution of the state. The point process contains all information one can get by position measurements and is determined by the latter. On the other hand, to each so-called Σ/sup c/-point process Q they relate a locally normal state with position distribution Q

  19. Self-exciting point process in modeling earthquake occurrences

    International Nuclear Information System (INIS)

    Pratiwi, H.; Slamet, I.; Respatiwulan; Saputro, D. R. S.

    2017-01-01

    In this paper, we present a procedure for modeling earthquake based on spatial-temporal point process. The magnitude distribution is expressed as truncated exponential and the event frequency is modeled with a spatial-temporal point process that is characterized uniquely by its associated conditional intensity process. The earthquakes can be regarded as point patterns that have a temporal clustering feature so we use self-exciting point process for modeling the conditional intensity function. The choice of main shocks is conducted via window algorithm by Gardner and Knopoff and the model can be fitted by maximum likelihood method for three random variables. (paper)

  20. Non-parametric Bayesian inference for inhomogeneous Markov point processes

    DEFF Research Database (Denmark)

    Berthelsen, Kasper Klitgaard; Møller, Jesper; Johansen, Per Michael

    is a shot noise process, and the interaction function for a pair of points depends only on the distance between the two points and is a piecewise linear function modelled by a marked Poisson process. Simulation of the resulting posterior using a Metropolis-Hastings algorithm in the "conventional" way...

  1. A tutorial on Palm distributions for spatial point processes

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Møller, Jesper; Waagepetersen, Rasmus Plenge

    2017-01-01

    This tutorial provides an introduction to Palm distributions for spatial point processes. Initially, in the context of finite point processes, we give an explicit definition of Palm distributions in terms of their density functions. Then we review Palm distributions in the general case. Finally, we...

  2. SHAPE FROM TEXTURE USING LOCALLY SCALED POINT PROCESSES

    Directory of Open Access Journals (Sweden)

    Eva-Maria Didden

    2015-09-01

    Full Text Available Shape from texture refers to the extraction of 3D information from 2D images with irregular texture. This paper introduces a statistical framework to learn shape from texture where convex texture elements in a 2D image are represented through a point process. In a first step, the 2D image is preprocessed to generate a probability map corresponding to an estimate of the unnormalized intensity of the latent point process underlying the texture elements. The latent point process is subsequently inferred from the probability map in a non-parametric, model free manner. Finally, the 3D information is extracted from the point pattern by applying a locally scaled point process model where the local scaling function represents the deformation caused by the projection of a 3D surface onto a 2D image.

  3. Mechanistic spatio-temporal point process models for marked point processes, with a view to forest stand data

    DEFF Research Database (Denmark)

    Møller, Jesper; Ghorbani, Mohammad; Rubak, Ege Holger

    We show how a spatial point process, where to each point there is associated a random quantitative mark, can be identified with a spatio-temporal point process specified by a conditional intensity function. For instance, the points can be tree locations, the marks can express the size of trees......, and the conditional intensity function can describe the distribution of a tree (i.e., its location and size) conditionally on the larger trees. This enable us to construct parametric statistical models which are easily interpretable and where likelihood-based inference is tractable. In particular, we consider maximum...

  4. Post-Processing in the Material-Point Method

    DEFF Research Database (Denmark)

    Andersen, Søren; Andersen, Lars Vabbersgaard

    The material-point method (MPM) is a numerical method for dynamic or static analysis of solids using a discretization in time and space. The method has shown to be successful in modelling physical problems involving large deformations, which are difficult to model with traditional numerical tools...... such as the finite element method. In the material-point method, a set of material points is utilized to track the problem in time and space, while a computational background grid is utilized to obtain spatial derivatives relevant to the physical problem. Currently, the research within the material-point method......-point method. The first idea involves associating a volume with each material point and displaying the deformation of this volume. In the discretization process, the physical domain is divided into a number of smaller volumes each represented by a simple shape; here quadrilaterals are chosen for the presented...

  5. Multivariate Product-Shot-noise Cox Point Process Models

    DEFF Research Database (Denmark)

    Jalilian, Abdollah; Guan, Yongtao; Mateu, Jorge

    We introduce a new multivariate product-shot-noise Cox process which is useful for model- ing multi-species spatial point patterns with clustering intra-specific interactions and neutral, negative or positive inter-specific interactions. The auto and cross pair correlation functions of the process...... can be obtained in closed analytical forms and approximate simulation of the process is straightforward. We use the proposed process to model interactions within and among five tree species in the Barro Colorado Island plot....

  6. PROCESSING UAV AND LIDAR POINT CLOUDS IN GRASS GIS

    Directory of Open Access Journals (Sweden)

    V. Petras

    2016-06-01

    Full Text Available Today’s methods of acquiring Earth surface data, namely lidar and unmanned aerial vehicle (UAV imagery, non-selectively collect or generate large amounts of points. Point clouds from different sources vary in their properties such as number of returns, density, or quality. We present a set of tools with applications for different types of points clouds obtained by a lidar scanner, structure from motion technique (SfM, and a low-cost 3D scanner. To take advantage of the vertical structure of multiple return lidar point clouds, we demonstrate tools to process them using 3D raster techniques which allow, for example, the development of custom vegetation classification methods. Dense point clouds obtained from UAV imagery, often containing redundant points, can be decimated using various techniques before further processing. We implemented and compared several decimation techniques in regard to their performance and the final digital surface model (DSM. Finally, we will describe the processing of a point cloud from a low-cost 3D scanner, namely Microsoft Kinect, and its application for interaction with physical models. All the presented tools are open source and integrated in GRASS GIS, a multi-purpose open source GIS with remote sensing capabilities. The tools integrate with other open source projects, specifically Point Data Abstraction Library (PDAL, Point Cloud Library (PCL, and OpenKinect libfreenect2 library to benefit from the open source point cloud ecosystem. The implementation in GRASS GIS ensures long term maintenance and reproducibility by the scientific community but also by the original authors themselves.

  7. Scattering analysis of point processes and random measures

    International Nuclear Information System (INIS)

    Hanisch, K.H.

    1984-01-01

    In the present paper scattering analysis of point processes and random measures is studied. Known formulae which connect the scattering intensity with the pair distribution function of the studied structures are proved in a rigorous manner with tools of the theory of point processes and random measures. For some special fibre processes the scattering intensity is computed. For a class of random measures, namely for 'grain-germ-models', a new formula is proved which yields the pair distribution function of the 'grain-germ-model' in terms of the pair distribution function of the underlying point process (the 'germs') and of the mean structure factor and the mean squared structure factor of the particles (the 'grains'). (author)

  8. Dew point vs bubble point : a misunderstood constraint on gravity drainage processes

    Energy Technology Data Exchange (ETDEWEB)

    Nenninger, J. [N-Solv Corp., Calgary, AB (Canada); Gunnewiek, L. [Hatch Ltd., Mississauga, ON (Canada)

    2009-07-01

    This study demonstrated that gravity drainage processes that use blended fluids such as solvents have an inherently unstable material balance due to differences between dew point and bubble point compositions. The instability can lead to the accumulation of volatile components within the chamber, and impair mass and heat transfer processes. Case studies were used to demonstrate the large temperature gradients within the vapour chamber caused by temperature differences between the bubble point and dew point for blended fluids. A review of published data showed that many experiments on in-situ processes do not account for unstable material balances caused by a lack of steam trap control. A study of temperature profiles during steam assisted gravity drainage (SAGD) studies showed significant temperature depressions caused by methane accumulations at the outside perimeter of the steam chamber. It was demonstrated that the condensation of large volumes of purified solvents provided an efficient mechanism for the removal of methane from the chamber. It was concluded that gravity drainage processes can be optimized by using pure propane during the injection process. 22 refs., 1 tab., 18 figs.

  9. The permanental process

    DEFF Research Database (Denmark)

    McCullagh, Peter; Møller, Jesper

    2006-01-01

    We extend the boson process first to a large class of Cox processes and second to an even larger class of infinitely divisible point processes. Density and moment results are studied in detail. These results are obtained in closed form as weighted permanents, so the extension i called a permanental...... process. Temporal extensions and a particularly tractable case of the permanental process are also studied. Extensions of the fermion process along similar lines, leading to so-called determinantal processes, are discussed....

  10. A MARKED POINT PROCESS MODEL FOR VEHICLE DETECTION IN AERIAL LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    A. Börcs

    2012-07-01

    Full Text Available In this paper we present an automated method for vehicle detection in LiDAR point clouds of crowded urban areas collected from an aerial platform. We assume that the input cloud is unordered, but it contains additional intensity and return number information which are jointly exploited by the proposed solution. Firstly, the 3-D point set is segmented into ground, vehicle, building roof, vegetation and clutter classes. Then the points with the corresponding class labels and intensity values are projected to the ground plane, where the optimal vehicle configuration is described by a Marked Point Process (MPP model of 2-D rectangles. Finally, the Multiple Birth and Death algorithm is utilized to find the configuration with the highest confidence.

  11. Pointo - a Low Cost Solution to Point Cloud Processing

    Science.gov (United States)

    Houshiar, H.; Winkler, S.

    2017-11-01

    With advance in technology access to data especially 3D point cloud data becomes more and more an everyday task. 3D point clouds are usually captured with very expensive tools such as 3D laser scanners or very time consuming methods such as photogrammetry. Most of the available softwares for 3D point cloud processing are designed for experts and specialists in this field and are usually very large software packages containing variety of methods and tools. This results in softwares that are usually very expensive to acquire and also very difficult to use. Difficulty of use is caused by complicated user interfaces that is required to accommodate a large list of features. The aim of these complex softwares is to provide a powerful tool for a specific group of specialist. However they are not necessary required by the majority of the up coming average users of point clouds. In addition to complexity and high costs of these softwares they generally rely on expensive and modern hardware and only compatible with one specific operating system. Many point cloud customers are not point cloud processing experts or willing to spend the high acquisition costs of these expensive softwares and hardwares. In this paper we introduce a solution for low cost point cloud processing. Our approach is designed to accommodate the needs of the average point cloud user. To reduce the cost and complexity of software our approach focuses on one functionality at a time in contrast with most available softwares and tools that aim to solve as many problems as possible at the same time. Our simple and user oriented design improve the user experience and empower us to optimize our methods for creation of an efficient software. In this paper we introduce Pointo family as a series of connected softwares to provide easy to use tools with simple design for different point cloud processing requirements. PointoVIEWER and PointoCAD are introduced as the first components of the Pointo family to provide a

  12. Investigation of Random Switching Driven by a Poisson Point Process

    DEFF Research Database (Denmark)

    Simonsen, Maria; Schiøler, Henrik; Leth, John-Josef

    2015-01-01

    This paper investigates the switching mechanism of a two-dimensional switched system, when the switching events are generated by a Poisson point process. A model, in the shape of a stochastic process, for such a system is derived and the distribution of the trajectory's position is developed...... together with marginal density functions for the coordinate functions. Furthermore, the joint probability distribution is given explicitly....

  13. On estimation of the intensity function of a point process

    NARCIS (Netherlands)

    Lieshout, van M.N.M.

    2010-01-01

    Abstract. Estimation of the intensity function of spatial point processes is a fundamental problem. In this paper, we interpret the Delaunay tessellation field estimator recently introduced by Schaap and Van de Weygaert as an adaptive kernel estimator and give explicit expressions for the mean and

  14. Spatio-temporal point process filtering methods with an application

    Czech Academy of Sciences Publication Activity Database

    Frcalová, B.; Beneš, V.; Klement, Daniel

    2010-01-01

    Roč. 21, 3-4 (2010), s. 240-252 ISSN 1180-4009 R&D Projects: GA AV ČR(CZ) IAA101120604 Institutional research plan: CEZ:AV0Z50110509 Keywords : cox point process * filtering * spatio-temporal modelling * spike Subject RIV: BA - General Mathematics Impact factor: 0.750, year: 2010

  15. A case study on point process modelling in disease mapping

    Czech Academy of Sciences Publication Activity Database

    Beneš, Viktor; Bodlák, M.; Moller, J.; Waagepetersen, R.

    2005-01-01

    Roč. 24, č. 3 (2005), s. 159-168 ISSN 1580-3139 R&D Projects: GA MŠk 0021620839; GA ČR GA201/03/0946 Institutional research plan: CEZ:AV0Z10750506 Keywords : log Gaussian Cox point process * Bayesian estimation Subject RIV: BB - Applied Statistics, Operational Research

  16. A J–function for inhomogeneous point processes

    NARCIS (Netherlands)

    M.N.M. van Lieshout (Marie-Colette)

    2010-01-01

    htmlabstractWe propose new summary statistics for intensity-reweighted moment stationary point processes that generalise the well known J-, empty space, and nearest-neighbour distance dis- tribution functions, represent them in terms of generating functionals and conditional intensities, and relate

  17. Some properties of point processes in statistical optics

    International Nuclear Information System (INIS)

    Picinbono, B.; Bendjaballah, C.

    2010-01-01

    The analysis of the statistical properties of the point process (PP) of photon detection times can be used to determine whether or not an optical field is classical, in the sense that its statistical description does not require the methods of quantum optics. This determination is, however, more difficult than ordinarily admitted and the first aim of this paper is to illustrate this point by using some results of the PP theory. For example, it is well known that the analysis of the photodetection of classical fields exhibits the so-called bunching effect. But this property alone cannot be used to decide the nature of a given optical field. Indeed, we have presented examples of point processes for which a bunching effect appears and yet they cannot be obtained from a classical field. These examples are illustrated by computer simulations. Similarly, it is often admitted that for fields with very low light intensity the bunching or antibunching can be described by using the statistical properties of the distance between successive events of the point process, which simplifies the experimental procedure. We have shown that, while this property is valid for classical PPs, it has no reason to be true for nonclassical PPs, and we have presented some examples of this situation also illustrated by computer simulations.

  18. Shot-noise-weighted processes : a new family of spatial point processes

    NARCIS (Netherlands)

    M.N.M. van Lieshout (Marie-Colette); I.S. Molchanov (Ilya)

    1995-01-01

    textabstractThe paper suggests a new family of of spatial point processes distributions. They are defined by means of densities with respect to the Poisson point process within a bounded set. These densities are given in terms of a functional of the shot-noise process with a given influence

  19. Decay of Complex-Time Determinantal and Pfaffian Correlation Functionals in Lattices

    Science.gov (United States)

    Aza, N. J. B.; Bru, J.-B.; de Siqueira Pedra, W.

    2018-06-01

    We supplement the determinantal and Pfaffian bounds of Sims and Warzel (Commun Math Phys 347:903-931, 2016) for many-body localization of quasi-free fermions, by considering the high dimensional case and complex-time correlations. Our proof uses the analyticity of correlation functions via the Hadamard three-line theorem. We show that the dynamical localization for the one-particle system yields the dynamical localization for the many-point fermionic correlation functions, with respect to the Hausdorff distance in the determinantal case. In Sims and Warzel (2016), a stronger notion of decay for many-particle configurations was used but only at dimension one and for real times. Considering determinantal and Pfaffian correlation functionals for complex times is important in the study of weakly interacting fermions.

  20. Decay of Complex-Time Determinantal and Pfaffian Correlation Functionals in Lattices

    Science.gov (United States)

    Aza, N. J. B.; Bru, J.-B.; de Siqueira Pedra, W.

    2018-04-01

    We supplement the determinantal and Pfaffian bounds of Sims and Warzel (Commun Math Phys 347:903-931, 2016) for many-body localization of quasi-free fermions, by considering the high dimensional case and complex-time correlations. Our proof uses the analyticity of correlation functions via the Hadamard three-line theorem. We show that the dynamical localization for the one-particle system yields the dynamical localization for the many-point fermionic correlation functions, with respect to the Hausdorff distance in the determinantal case. In Sims and Warzel (2016), a stronger notion of decay for many-particle configurations was used but only at dimension one and for real times. Considering determinantal and Pfaffian correlation functionals for complex times is important in the study of weakly interacting fermions.

  1. Determinantes do processo de infestação domiciliar por Panstrongylus megistus: o papel da habitação e do desmatamento Determinants of the dwelling infestation process by Panstrongylus megistus: the role of housing and deforesting

    Directory of Open Access Journals (Sweden)

    Julio Litvoc

    1990-12-01

    Full Text Available A qualidade das habitações e o desmatamento foram estudados em Caconde e São José do Rio Pardo, municípios paulistas com taxas diferenciadas de infestação domiciliar por Panstrongylus megistus, e com desenvolvimento sócio-econômico dessemelhante. Para o conhecimento da qualidade das habitações recorreu-se a dados registrados na Superintendência de Controle de Endemias (SUCEN durante a década de 70; o estudo do desmatamento foi realizado em mapas, construídos por nós a partir de fotografias aéreas, obtidas em vôos realizados pela Secretaria de Agricultura em 1972 e 1983. A análise sócio-econômica baseou-se nas informações do Censo Agro-pecuário e em entrevistas com agrônomos dos municípios. O estudo mostrou uma situação de maior precariedade das casas em Caconde. Essa situação decorre do menor desenvolvimento sócio-econômico deste município, confirmando assim uma tendência já demonstrada em pesquisas anteriores. O desmatamento foi mais intenso em São José, onde o desenvolvimento social é maior e no qual à taxa de infestação é menor, fato que mostra um comportamento oposto entre os dois determinantes nestes municípios. Os vínculos entre o desmatamento e o maior desenvolvimento sócio-econômico pode também ser demonstrado na medida em que se pode relacionar a atividade produtiva com a destruição da cobertura vegetal natural. Cabe sublinhar que esta tendência de efeito oposto do desmatamento não inverteu o resultado final, ou seja, que o confronto dessas forças determinantes resultou ainda numa taxa de infestação superior em Caconde, área de menor desenvolvimento social. A existência dessas tendências opostas entre os determinantes revela, desse modo, uma maior complexidade no processo de infestação por P. megistus, sem produzir, no entanto, reversão do resultado final.This study investigates the housing conditions and deforesting in Caconde and São José do Rio Pardo, neighbouring towns

  2. Robust and Efficient Spin Purification for Determinantal Configuration Interaction.

    Science.gov (United States)

    Fales, B Scott; Hohenstein, Edward G; Levine, Benjamin G

    2017-09-12

    The limited precision of floating point arithmetic can lead to the qualitative and even catastrophic failure of quantum chemical algorithms, especially when high accuracy solutions are sought. For example, numerical errors accumulated while solving for determinantal configuration interaction wave functions via Davidson diagonalization may lead to spin contamination in the trial subspace. This spin contamination may cause the procedure to converge to roots with undesired ⟨Ŝ 2 ⟩, wasting computer time in the best case and leading to incorrect conclusions in the worst. In hopes of finding a suitable remedy, we investigate five purification schemes for ensuring that the eigenvectors have the desired ⟨Ŝ 2 ⟩. These schemes are based on projection, penalty, and iterative approaches. All of these schemes rely on a direct, graphics processing unit-accelerated algorithm for calculating the S 2 c matrix-vector product. We assess the computational cost and convergence behavior of these methods by application to several benchmark systems and find that the first-order spin penalty method is the optimal choice, though first-order and Löwdin projection approaches also provide fast convergence to the desired spin state. Finally, to demonstrate the utility of these approaches, we computed the lowest several excited states of an open-shell silver cluster (Ag 19 ) using the state-averaged complete active space self-consistent field method, where spin purification was required to ensure spin stability of the CI vector coefficients. Several low-lying states with significant multiply excited character are predicted, suggesting the value of a multireference approach for modeling plasmonic nanomaterials.

  3. Two-step estimation for inhomogeneous spatial point processes

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus; Guan, Yongtao

    This paper is concerned with parameter estimation for inhomogeneous spatial point processes with a regression model for the intensity function and tractable second order properties (K-function). Regression parameters are estimated using a Poisson likelihood score estimating function and in a second...... step minimum contrast estimation is applied for the residual clustering parameters. Asymptotic normality of parameter estimates is established under certain mixing conditions and we exemplify how the results may be applied in ecological studies of rain forests....

  4. A case study on point process modelling in disease mapping

    DEFF Research Database (Denmark)

    Møller, Jesper; Waagepetersen, Rasmus Plenge; Benes, Viktor

    2005-01-01

    of the risk on the covariates. Instead of using the common areal level approaches we base the analysis on a Bayesian approach for a log Gaussian Cox point process with covariates. Posterior characteristics for a discretized version of the log Gaussian Cox process are computed using Markov chain Monte Carlo...... methods. A particular problem which is thoroughly discussed is to determine a model for the background population density. The risk map shows a clear dependency with the population intensity models and the basic model which is adopted for the population intensity determines what covariates influence...... the risk of TBE. Model validation is based on the posterior predictive distribution of various summary statistics....

  5. A Marked Point Process Framework for Extracellular Electrical Potentials

    Directory of Open Access Journals (Sweden)

    Carlos A. Loza

    2017-12-01

    Full Text Available Neuromodulations are an important component of extracellular electrical potentials (EEP, such as the Electroencephalogram (EEG, Electrocorticogram (ECoG and Local Field Potentials (LFP. This spatially temporal organized multi-frequency transient (phasic activity reflects the multiscale spatiotemporal synchronization of neuronal populations in response to external stimuli or internal physiological processes. We propose a novel generative statistical model of a single EEP channel, where the collected signal is regarded as the noisy addition of reoccurring, multi-frequency phasic events over time. One of the main advantages of the proposed framework is the exceptional temporal resolution in the time location of the EEP phasic events, e.g., up to the sampling period utilized in the data collection. Therefore, this allows for the first time a description of neuromodulation in EEPs as a Marked Point Process (MPP, represented by their amplitude, center frequency, duration, and time of occurrence. The generative model for the multi-frequency phasic events exploits sparseness and involves a shift-invariant implementation of the clustering technique known as k-means. The cost function incorporates a robust estimation component based on correntropy to mitigate the outliers caused by the inherent noise in the EEP. Lastly, the background EEP activity is explicitly modeled as the non-sparse component of the collected signal to further improve the delineation of the multi-frequency phasic events in time. The framework is validated using two publicly available datasets: the DREAMS sleep spindles database and one of the Brain-Computer Interface (BCI competition datasets. The results achieve benchmark performance and provide novel quantitative descriptions based on power, event rates and timing in order to assess behavioral correlates beyond the classical power spectrum-based analysis. This opens the possibility for a unifying point process framework of

  6. Framework for adaptive multiscale analysis of nonhomogeneous point processes.

    Science.gov (United States)

    Helgason, Hannes; Bartroff, Jay; Abry, Patrice

    2011-01-01

    We develop the methodology for hypothesis testing and model selection in nonhomogeneous Poisson processes, with an eye toward the application of modeling and variability detection in heart beat data. Modeling the process' non-constant rate function using templates of simple basis functions, we develop the generalized likelihood ratio statistic for a given template and a multiple testing scheme to model-select from a family of templates. A dynamic programming algorithm inspired by network flows is used to compute the maximum likelihood template in a multiscale manner. In a numerical example, the proposed procedure is nearly as powerful as the super-optimal procedures that know the true template size and true partition, respectively. Extensions to general history-dependent point processes is discussed.

  7. Simple computation of reaction–diffusion processes on point clouds

    KAUST Repository

    Macdonald, Colin B.; Merriman, Barry; Ruuth, Steven J.

    2013-01-01

    The study of reaction-diffusion processes is much more complicated on general curved surfaces than on standard Cartesian coordinate spaces. Here we show how to formulate and solve systems of reaction-diffusion equations on surfaces in an extremely simple way, using only the standard Cartesian form of differential operators, and a discrete unorganized point set to represent the surface. Our method decouples surface geometry from the underlying differential operators. As a consequence, it becomes possible to formulate and solve rather general reaction-diffusion equations on general surfaces without having to consider the complexities of differential geometry or sophisticated numerical analysis. To illustrate the generality of the method, computations for surface diffusion, pattern formation, excitable media, and bulk-surface coupling are provided for a variety of complex point cloud surfaces.

  8. Simple computation of reaction–diffusion processes on point clouds

    KAUST Repository

    Macdonald, Colin B.

    2013-05-20

    The study of reaction-diffusion processes is much more complicated on general curved surfaces than on standard Cartesian coordinate spaces. Here we show how to formulate and solve systems of reaction-diffusion equations on surfaces in an extremely simple way, using only the standard Cartesian form of differential operators, and a discrete unorganized point set to represent the surface. Our method decouples surface geometry from the underlying differential operators. As a consequence, it becomes possible to formulate and solve rather general reaction-diffusion equations on general surfaces without having to consider the complexities of differential geometry or sophisticated numerical analysis. To illustrate the generality of the method, computations for surface diffusion, pattern formation, excitable media, and bulk-surface coupling are provided for a variety of complex point cloud surfaces.

  9. Statistical representation of a spray as a point process

    International Nuclear Information System (INIS)

    Subramaniam, S.

    2000-01-01

    The statistical representation of a spray as a finite point process is investigated. One objective is to develop a better understanding of how single-point statistical information contained in descriptions such as the droplet distribution function (ddf), relates to the probability density functions (pdfs) associated with the droplets themselves. Single-point statistical information contained in the droplet distribution function (ddf) is shown to be related to a sequence of single surrogate-droplet pdfs, which are in general different from the physical single-droplet pdfs. It is shown that the ddf contains less information than the fundamental single-point statistical representation of the spray, which is also described. The analysis shows which events associated with the ensemble of spray droplets can be characterized by the ddf, and which cannot. The implications of these findings for the ddf approach to spray modeling are discussed. The results of this study also have important consequences for the initialization and evolution of direct numerical simulations (DNS) of multiphase flows, which are usually initialized on the basis of single-point statistics such as the droplet number density in physical space. If multiphase DNS are initialized in this way, this implies that even the initial representation contains certain implicit assumptions concerning the complete ensemble of realizations, which are invalid for general multiphase flows. Also the evolution of a DNS initialized in this manner is shown to be valid only if an as yet unproven commutation hypothesis holds true. Therefore, it is questionable to what extent DNS that are initialized in this manner constitute a direct simulation of the physical droplets. Implications of these findings for large eddy simulations of multiphase flows are also discussed. (c) 2000 American Institute of Physics

  10. Energy risk management through self-exciting marked point process

    International Nuclear Information System (INIS)

    Herrera, Rodrigo

    2013-01-01

    Crude oil is a dynamically traded commodity that affects many economies. We propose a collection of marked self-exciting point processes with dependent arrival rates for extreme events in oil markets and related risk measures. The models treat the time among extreme events in oil markets as a stochastic process. The main advantage of this approach is its capability to capture the short, medium and long-term behavior of extremes without involving an arbitrary stochastic volatility model or a prefiltration of the data, as is common in extreme value theory applications. We make use of the proposed model in order to obtain an improved estimate for the Value at Risk in oil markets. Empirical findings suggest that the reliability and stability of Value at Risk estimates improve as a result of finer modeling approach. This is supported by an empirical application in the representative West Texas Intermediate (WTI) and Brent crude oil markets. - Highlights: • We propose marked self-exciting point processes for extreme events in oil markets. • This approach captures the short and long-term behavior of extremes. • We improve the estimates for the VaR in the WTI and Brent crude oil markets

  11. Weak convergence of marked point processes generated by crossings of multivariate jump processes

    DEFF Research Database (Denmark)

    Tamborrino, Massimiliano; Sacerdote, Laura; Jacobsen, Martin

    2014-01-01

    We consider the multivariate point process determined by the crossing times of the components of a multivariate jump process through a multivariate boundary, assuming to reset each component to an initial value after its boundary crossing. We prove that this point process converges weakly...... process converging to a multivariate Ornstein–Uhlenbeck process is discussed as a guideline for applying diffusion limits for jump processes. We apply our theoretical findings to neural network modeling. The proposed model gives a mathematical foundation to the generalization of the class of Leaky...

  12. Variational approach for spatial point process intensity estimation

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Møller, Jesper

    is assumed to be of log-linear form β+θ⊤z(u) where z is a spatial covariate function and the focus is on estimating θ. The variational estimator is very simple to implement and quicker than alternative estimation procedures. We establish its strong consistency and asymptotic normality. We also discuss its...... finite-sample properties in comparison with the maximum first order composite likelihood estimator when considering various inhomogeneous spatial point process models and dimensions as well as settings were z is completely or only partially known....

  13. Two-step estimation for inhomogeneous spatial point processes

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus; Guan, Yongtao

    2009-01-01

    The paper is concerned with parameter estimation for inhomogeneous spatial point processes with a regression model for the intensity function and tractable second-order properties (K-function). Regression parameters are estimated by using a Poisson likelihood score estimating function and in the ...... and in the second step minimum contrast estimation is applied for the residual clustering parameters. Asymptotic normality of parameter estimates is established under certain mixing conditions and we exemplify how the results may be applied in ecological studies of rainforests....

  14. Multiple Monte Carlo Testing with Applications in Spatial Point Processes

    DEFF Research Database (Denmark)

    Mrkvička, Tomáš; Myllymäki, Mari; Hahn, Ute

    with a function as the test statistic, 3) several Monte Carlo tests with functions as test statistics. The rank test has correct (global) type I error in each case and it is accompanied with a p-value and with a graphical interpretation which shows which subtest or which distances of the used test function......(s) lead to the rejection at the prescribed significance level of the test. Examples of null hypothesis from point process and random set statistics are used to demonstrate the strength of the rank envelope test. The examples include goodness-of-fit test with several test functions, goodness-of-fit test...

  15. CLINSULF sub-dew-point process for sulphur recovery

    Energy Technology Data Exchange (ETDEWEB)

    Heisel, M.; Marold, F.

    1988-01-01

    In a 2-reactor system, the CLINSULF process allows very high sulphur recovery rates. When operated at 100/sup 0/C at the outlet, i.e. below the sulphur solidification point, a sulphur recovery rate of more than 99.2% was achieved in a 2-reactor series. Assuming a 70% sulphur recovery in an upstream Claus furnace plus sulphur condenser, an overall sulphur recovery of more than 99.8% results for the 2-reactor system. This is approximately 2% higher than in conventional Claus plus SDP units, which mostly consist of 4 reactors or more. This means the the CLINSULF SSP process promises to be an improvement both in respect of efficiency and low investment cost.

  16. Self-Exciting Point Process Modeling of Conversation Event Sequences

    Science.gov (United States)

    Masuda, Naoki; Takaguchi, Taro; Sato, Nobuo; Yano, Kazuo

    Self-exciting processes of Hawkes type have been used to model various phenomena including earthquakes, neural activities, and views of online videos. Studies of temporal networks have revealed that sequences of social interevent times for individuals are highly bursty. We examine some basic properties of event sequences generated by the Hawkes self-exciting process to show that it generates bursty interevent times for a wide parameter range. Then, we fit the model to the data of conversation sequences recorded in company offices in Japan. In this way, we can estimate relative magnitudes of the self excitement, its temporal decay, and the base event rate independent of the self excitation. These variables highly depend on individuals. We also point out that the Hawkes model has an important limitation that the correlation in the interevent times and the burstiness cannot be independently modulated.

  17. Imitation learning of Non-Linear Point-to-Point Robot Motions using Dirichlet Processes

    DEFF Research Database (Denmark)

    Krüger, Volker; Tikhanoff, Vadim; Natale, Lorenzo

    2012-01-01

    In this paper we discuss the use of the infinite Gaussian mixture model and Dirichlet processes for learning robot movements from demonstrations. Starting point of this work is an earlier paper where the authors learn a non-linear dynamic robot movement model from a small number of observations....... The model in that work is learned using a classical finite Gaussian mixture model (FGMM) where the Gaussian mixtures are appropriately constrained. The problem with this approach is that one needs to make a good guess for how many mixtures the FGMM should use. In this work, we generalize this approach...... our algorithm on the same data that was used in [5], where the authors use motion capture devices to record the demonstrations. As further validation we test our approach on novel data acquired on our iCub in a different demonstration scenario in which the robot is physically driven by the human...

  18. Benchmarking of radiological departments. Starting point for successful process optimization

    International Nuclear Information System (INIS)

    Busch, Hans-Peter

    2010-01-01

    Continuous optimization of the process of organization and medical treatment is part of the successful management of radiological departments. The focus of this optimization can be cost units such as CT and MRI or the radiological parts of total patient treatment. Key performance indicators for process optimization are cost- effectiveness, service quality and quality of medical treatment. The potential for improvements can be seen by comparison (benchmark) with other hospitals and radiological departments. Clear definitions of key data and criteria are absolutely necessary for comparability. There is currently little information in the literature regarding the methodology and application of benchmarks especially from the perspective of radiological departments and case-based lump sums, even though benchmarking has frequently been applied to radiological departments by hospital management. The aim of this article is to describe and discuss systematic benchmarking as an effective starting point for successful process optimization. This includes the description of the methodology, recommendation of key parameters and discussion of the potential for cost-effectiveness analysis. The main focus of this article is cost-effectiveness (efficiency and effectiveness) with respect to cost units and treatment processes. (orig.)

  19. Determinantal spanning forests on planar graphs

    OpenAIRE

    Kenyon, Richard

    2017-01-01

    We generalize the uniform spanning tree to construct a family of determinantal measures on essential spanning forests on periodic planar graphs in which every component tree is bi-infinite. Like the uniform spanning tree, these measures arise naturally from the laplacian on the graph. More generally these results hold for the "massive" laplacian determinant which counts rooted spanning forests with weight $M$ per finite component. These measures typically have a form of conformal invariance, ...

  20. A CASE STUDY ON POINT PROCESS MODELLING IN DISEASE MAPPING

    Directory of Open Access Journals (Sweden)

    Viktor Beneš

    2011-05-01

    Full Text Available We consider a data set of locations where people in Central Bohemia have been infected by tick-borne encephalitis (TBE, and where population census data and covariates concerning vegetation and altitude are available. The aims are to estimate the risk map of the disease and to study the dependence of the risk on the covariates. Instead of using the common area level approaches we base the analysis on a Bayesian approach for a log Gaussian Cox point process with covariates. Posterior characteristics for a discretized version of the log Gaussian Cox process are computed using Markov chain Monte Carlo methods. A particular problem which is thoroughly discussed is to determine a model for the background population density. The risk map shows a clear dependency with the population intensity models and the basic model which is adopted for the population intensity determines what covariates influence the risk of TBE. Model validation is based on the posterior predictive distribution of various summary statistics.

  1. Mean-field inference of Hawkes point processes

    International Nuclear Information System (INIS)

    Bacry, Emmanuel; Gaïffas, Stéphane; Mastromatteo, Iacopo; Muzy, Jean-François

    2016-01-01

    We propose a fast and efficient estimation method that is able to accurately recover the parameters of a d-dimensional Hawkes point-process from a set of observations. We exploit a mean-field approximation that is valid when the fluctuations of the stochastic intensity are small. We show that this is notably the case in situations when interactions are sufficiently weak, when the dimension of the system is high or when the fluctuations are self-averaging due to the large number of past events they involve. In such a regime the estimation of a Hawkes process can be mapped on a least-squares problem for which we provide an analytic solution. Though this estimator is biased, we show that its precision can be comparable to the one of the maximum likelihood estimator while its computation speed is shown to be improved considerably. We give a theoretical control on the accuracy of our new approach and illustrate its efficiency using synthetic datasets, in order to assess the statistical estimation error of the parameters. (paper)

  2. Corner-point criterion for assessing nonlinear image processing imagers

    Science.gov (United States)

    Landeau, Stéphane; Pigois, Laurent; Foing, Jean-Paul; Deshors, Gilles; Swiathy, Greggory

    2017-10-01

    Range performance modeling of optronics imagers attempts to characterize the ability to resolve details in the image. Today, digital image processing is systematically used in conjunction with the optoelectronic system to correct its defects or to exploit tiny detection signals to increase performance. In order to characterize these processing having adaptive and non-linear properties, it becomes necessary to stimulate the imagers with test patterns whose properties are similar to the actual scene image ones, in terms of dynamic range, contours, texture and singular points. This paper presents an approach based on a Corner-Point (CP) resolution criterion, derived from the Probability of Correct Resolution (PCR) of binary fractal patterns. The fundamental principle lies in the respectful perception of the CP direction of one pixel minority value among the majority value of a 2×2 pixels block. The evaluation procedure considers the actual image as its multi-resolution CP transformation, taking the role of Ground Truth (GT). After a spatial registration between the degraded image and the original one, the degradation is statistically measured by comparing the GT with the degraded image CP transformation, in terms of localized PCR at the region of interest. The paper defines this CP criterion and presents the developed evaluation techniques, such as the measurement of the number of CP resolved on the target, the transformation CP and its inverse transform that make it possible to reconstruct an image of the perceived CPs. Then, this criterion is compared with the standard Johnson criterion, in the case of a linear blur and noise degradation. The evaluation of an imaging system integrating an image display and a visual perception is considered, by proposing an analysis scheme combining two methods: a CP measurement for the highly non-linear part (imaging) with real signature test target and conventional methods for the more linear part (displaying). The application to

  3. Multiplicative point process as a model of trading activity

    Science.gov (United States)

    Gontis, V.; Kaulakys, B.

    2004-11-01

    Signals consisting of a sequence of pulses show that inherent origin of the 1/ f noise is a Brownian fluctuation of the average interevent time between subsequent pulses of the pulse sequence. In this paper, we generalize the model of interevent time to reproduce a variety of self-affine time series exhibiting power spectral density S( f) scaling as a power of the frequency f. Furthermore, we analyze the relation between the power-law correlations and the origin of the power-law probability distribution of the signal intensity. We introduce a stochastic multiplicative model for the time intervals between point events and analyze the statistical properties of the signal analytically and numerically. Such model system exhibits power-law spectral density S( f)∼1/ fβ for various values of β, including β= {1}/{2}, 1 and {3}/{2}. Explicit expressions for the power spectra in the low-frequency limit and for the distribution density of the interevent time are obtained. The counting statistics of the events is analyzed analytically and numerically, as well. The specific interest of our analysis is related with the financial markets, where long-range correlations of price fluctuations largely depend on the number of transactions. We analyze the spectral density and counting statistics of the number of transactions. The model reproduces spectral properties of the real markets and explains the mechanism of power-law distribution of trading activity. The study provides evidence that the statistical properties of the financial markets are enclosed in the statistics of the time interval between trades. A multiplicative point process serves as a consistent model generating this statistics.

  4. Determinantes de la organización de los espacios en los conjuntos educacionales. Una experiencia cubana

    Directory of Open Access Journals (Sweden)

    Martínez Pillot, Ledia

    1986-12-01

    Full Text Available This work sets forth criteria on determining factors which influence the desing of buildings groups, focused on from the general and conceptual point of view and it points out several concepts and Instruments which allow measuring the relations between the components and the stages which constitute the process of designing educational building groups. As part of the work on these determinants, the following aspects are studied: -Analysis of criteria for the selection of sites: how this activity is carried out within the Cuban political and social framework. -Treatment of exterior spaces: as part of the organic interpretation between educational spaces and the remaining areas, for a greater participation in the social and educational life of the pupil and of other inhabitants of the school center. -Analysis for growth: from the urban scale to physical plant-type spaces. Growth is a point to be taken into account in the process of analyzing the building group design so that it could maintain its integrity, considering certain degrees of flexibility which would permit adaptation to prospective changes in educational Systems. These determinants can be interpreted and reflected in the examples which constitute a practical Cuban experiment.Este trabajo expone criterios sobre determinantes que influyen en el Diseño de Conjuntos, enfocados desde el punto de vista general y conceptual y señala algunos conceptos e instrumentos que permiten medir las relaciones entre los componentes y las etapas que constituyen el proceso de Diseño de Conjuntos Educacionales. Como parte del trabajo de dichas determinantes, se desarrollan los aspectos siguientes: -Análisis de criterios para la selección de terrenos: cómo se desarrolla esta actividad en la estructura política y social cubana. -Tratamiento de los espacios exteriores: como parte de la integración orgánica entre los espacios educativos y demás áreas, para una mayor participación de la vida

  5. Seeking a fingerprint: analysis of point processes in actigraphy recording

    Science.gov (United States)

    Gudowska-Nowak, Ewa; Ochab, Jeremi K.; Oleś, Katarzyna; Beldzik, Ewa; Chialvo, Dante R.; Domagalik, Aleksandra; Fąfrowicz, Magdalena; Marek, Tadeusz; Nowak, Maciej A.; Ogińska, Halszka; Szwed, Jerzy; Tyburczyk, Jacek

    2016-05-01

    Motor activity of humans displays complex temporal fluctuations which can be characterised by scale-invariant statistics, thus demonstrating that structure and fluctuations of such kinetics remain similar over a broad range of time scales. Previous studies on humans regularly deprived of sleep or suffering from sleep disorders predicted a change in the invariant scale parameters with respect to those for healthy subjects. In this study we investigate the signal patterns from actigraphy recordings by means of characteristic measures of fractional point processes. We analyse spontaneous locomotor activity of healthy individuals recorded during a week of regular sleep and a week of chronic partial sleep deprivation. Behavioural symptoms of lack of sleep can be evaluated by analysing statistics of duration times during active and resting states, and alteration of behavioural organisation can be assessed by analysis of power laws detected in the event count distribution, distribution of waiting times between consecutive movements and detrended fluctuation analysis of recorded time series. We claim that among different measures characterising complexity of the actigraphy recordings and their variations implied by chronic sleep distress, the exponents characterising slopes of survival functions in resting states are the most effective biomarkers distinguishing between healthy and sleep-deprived groups.

  6. A scalable and multi-purpose point cloud server (PCS) for easier and faster point cloud data management and processing

    Science.gov (United States)

    Cura, Rémi; Perret, Julien; Paparoditis, Nicolas

    2017-05-01

    In addition to more traditional geographical data such as images (rasters) and vectors, point cloud data are becoming increasingly available. Such data are appreciated for their precision and true three-Dimensional (3D) nature. However, managing point clouds can be difficult due to scaling problems and specificities of this data type. Several methods exist but are usually fairly specialised and solve only one aspect of the management problem. In this work, we propose a comprehensive and efficient point cloud management system based on a database server that works on groups of points (patches) rather than individual points. This system is specifically designed to cover the basic needs of point cloud users: fast loading, compressed storage, powerful patch and point filtering, easy data access and exporting, and integrated processing. Moreover, the proposed system fully integrates metadata (like sensor position) and can conjointly use point clouds with other geospatial data, such as images, vectors, topology and other point clouds. Point cloud (parallel) processing can be done in-base with fast prototyping capabilities. Lastly, the system is built on open source technologies; therefore it can be easily extended and customised. We test the proposed system with several billion points obtained from Lidar (aerial and terrestrial) and stereo-vision. We demonstrate loading speeds in the ˜50 million pts/h per process range, transparent-for-user and greater than 2 to 4:1 compression ratio, patch filtering in the 0.1 to 1 s range, and output in the 0.1 million pts/s per process range, along with classical processing methods, such as object detection.

  7. Equivalence of functional limit theorems for stationary point processes and their Palm distributions

    NARCIS (Netherlands)

    Nieuwenhuis, G.

    1989-01-01

    Let P be the distribution of a stationary point process on the real line and let P0 be its Palm distribution. In this paper we consider two types of functional limit theorems, those in terms of the number of points of the point process in (0, t] and those in terms of the location of the nth point

  8. Microbial profile and critical control points during processing of 'robo ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... frying, surface fat draining, open-air cooling, and holding/packaging in polyethylene films during sales and distribution. The product was, however, classified under category III with respect to risk and the significance of monitoring and evaluation of quality using the hazard analysis critical control point.

  9. Discussion of "Modern statistics for spatial point processes"

    DEFF Research Database (Denmark)

    Jensen, Eva Bjørn Vedel; Prokesová, Michaela; Hellmund, Gunnar

    2007-01-01

    ABSTRACT. The paper ‘Modern statistics for spatial point processes’ by Jesper Møller and Rasmus P. Waagepetersen is based on a special invited lecture given by the authors at the 21st Nordic Conference on Mathematical Statistics, held at Rebild, Denmark, in June 2006. At the conference, Antti...

  10. Geometric anisotropic spatial point pattern analysis and Cox processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Toftaker, Håkon

    . In particular we study Cox process models with an elliptical pair correlation function, including shot noise Cox processes and log Gaussian Cox processes, and we develop estimation procedures using summary statistics and Bayesian methods. Our methodology is illustrated on real and synthetic datasets of spatial...

  11. Process for structural geologic analysis of topography and point data

    Science.gov (United States)

    Eliason, Jay R.; Eliason, Valerie L. C.

    1987-01-01

    A quantitative method of geologic structural analysis of digital terrain data is described for implementation on a computer. Assuming selected valley segments are controlled by the underlying geologic structure, topographic lows in the terrain data, defining valley bottoms, are detected, filtered and accumulated into a series line segments defining contiguous valleys. The line segments are then vectorized to produce vector segments, defining valley segments, which may be indicative of the underlying geologic structure. Coplanar analysis is performed on vector segment pairs to determine which vectors produce planes which represent underlying geologic structure. Point data such as fracture phenomena which can be related to fracture planes in 3-dimensional space can be analyzed to define common plane orientation and locations. The vectors, points, and planes are displayed in various formats for interpretation.

  12. A Bayesian MCMC method for point process models with intractable normalising constants

    DEFF Research Database (Denmark)

    Berthelsen, Kasper Klitgaard; Møller, Jesper

    2004-01-01

    to simulate from the "unknown distribution", perfect simulation algorithms become useful. We illustrate the method in cases whre the likelihood is given by a Markov point process model. Particularly, we consider semi-parametric Bayesian inference in connection to both inhomogeneous Markov point process models...... and pairwise interaction point processes....

  13. INHOMOGENEITY IN SPATIAL COX POINT PROCESSES – LOCATION DEPENDENT THINNING IS NOT THE ONLY OPTION

    Directory of Open Access Journals (Sweden)

    Michaela Prokešová

    2010-11-01

    Full Text Available In the literature on point processes the by far most popular option for introducing inhomogeneity into a point process model is the location dependent thinning (resulting in a second-order intensity-reweighted stationary point process. This produces a very tractable model and there are several fast estimation procedures available. Nevertheless, this model dilutes the interaction (or the geometrical structure of the original homogeneous model in a special way. When concerning the Markov point processes several alternative inhomogeneous models were suggested and investigated in the literature. But it is not so for the Cox point processes, the canonical models for clustered point patterns. In the contribution we discuss several other options how to define inhomogeneous Cox point process models that result in point patterns with different types of geometric structure. We further investigate the possible parameter estimation procedures for such models.

  14. Marked point process for modelling seismic activity (case study in Sumatra and Java)

    Science.gov (United States)

    Pratiwi, Hasih; Sulistya Rini, Lia; Wayan Mangku, I.

    2018-05-01

    Earthquake is a natural phenomenon that is random, irregular in space and time. Until now the forecast of earthquake occurrence at a location is still difficult to be estimated so that the development of earthquake forecast methodology is still carried out both from seismology aspect and stochastic aspect. To explain the random nature phenomena, both in space and time, a point process approach can be used. There are two types of point processes: temporal point process and spatial point process. The temporal point process relates to events observed over time as a sequence of time, whereas the spatial point process describes the location of objects in two or three dimensional spaces. The points on the point process can be labelled with additional information called marks. A marked point process can be considered as a pair (x, m) where x is the point of location and m is the mark attached to the point of that location. This study aims to model marked point process indexed by time on earthquake data in Sumatra Island and Java Island. This model can be used to analyse seismic activity through its intensity function by considering the history process up to time before t. Based on data obtained from U.S. Geological Survey from 1973 to 2017 with magnitude threshold 5, we obtained maximum likelihood estimate for parameters of the intensity function. The estimation of model parameters shows that the seismic activity in Sumatra Island is greater than Java Island.

  15. Lasso and probabilistic inequalities for multivariate point processes

    DEFF Research Database (Denmark)

    Hansen, Niels Richard; Reynaud-Bouret, Patricia; Rivoirard, Vincent

    2015-01-01

    Due to its low computational cost, Lasso is an attractive regularization method for high-dimensional statistical settings. In this paper, we consider multivariate counting processes depending on an unknown function parameter to be estimated by linear combinations of a fixed dictionary. To select...... for multivariate Hawkes processes are proven, which allows us to check these assumptions by considering general dictionaries based on histograms, Fourier or wavelet bases. Motivated by problems of neuronal activity inference, we finally carry out a simulation study for multivariate Hawkes processes and compare our...... methodology with the adaptive Lasso procedure proposed by Zou in (J. Amer. Statist. Assoc. 101 (2006) 1418–1429). We observe an excellent behavior of our procedure. We rely on theoretical aspects for the essential question of tuning our methodology. Unlike adaptive Lasso of (J. Amer. Statist. Assoc. 101 (2006...

  16. Modelling financial high frequency data using point processes

    DEFF Research Database (Denmark)

    Hautsch, Nikolaus; Bauwens, Luc

    In this chapter written for a forthcoming Handbook of Financial Time Series to be published by Springer-Verlag, we review the econometric literature on dynamic duration and intensity processes applied to high frequency financial data, which was boosted by the work of Engle and Russell (1997...

  17. Lasso and probabilistic inequalities for multivariate point processes

    OpenAIRE

    Hansen, Niels Richard; Reynaud-Bouret, Patricia; Rivoirard, Vincent

    2012-01-01

    Due to its low computational cost, Lasso is an attractive regularization method for high-dimensional statistical settings. In this paper, we consider multivariate counting processes depending on an unknown function parameter to be estimated by linear combinations of a fixed dictionary. To select coefficients, we propose an adaptive $\\ell_{1}$-penalization methodology, where data-driven weights of the penalty are derived from new Bernstein type inequalities for martingales. Oracle inequalities...

  18. The S-Process Branching-Point at 205PB

    Science.gov (United States)

    Tonchev, Anton; Tsoneva, N.; Bhatia, C.; Arnold, C. W.; Goriely, S.; Hammond, S. L.; Kelley, J. H.; Kwan, E.; Lenske, H.; Piekarewicz, J.; Raut, R.; Rusev, G.; Shizuma, T.; Tornow, W.

    2017-09-01

    Accurate neutron-capture cross sections for radioactive nuclei near the line of beta stability are crucial for understanding s-process nucleosynthesis. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. We consider photon scattering using monoenergetic and 100% linearly polarized photon beams to obtain the photoabsorption cross section on 206Pb below the neutron separation energy. This observable becomes an essential ingredient in the Hauser-Feshbach statistical model for calculations of capture cross sections on 205Pb. The newly obtained photoabsorption information is also used to estimate the Maxwellian-averaged radiative cross section of 205Pb(n,g)206Pb at 30 keV. The astrophysical impact of this measurement on s-process nucleosynthesis will be discussed. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344.

  19. The Hinkley Point decision: An analysis of the policy process

    International Nuclear Information System (INIS)

    Thomas, Stephen

    2016-01-01

    In 2006, the British government launched a policy to build nuclear power reactors based on a claim that the power produced would be competitive with fossil fuel and would require no public subsidy. A decade later, it is not clear how many, if any, orders will be placed and the claims on costs and subsidies have proved false. Despite this failure to deliver, the policy is still being pursued with undiminished determination. The finance model that is now proposed is seen as a model other European countries can follow so the success or otherwise of the British nuclear programme will have implications outside the UK. This paper contends that the checks and balances that should weed out misguided policies, have failed. It argues that the most serious failure is with the civil service and its inability to provide politicians with high quality advice – truth to power. It concludes that the failure is likely to be due to the unwillingness of politicians to listen to opinions that conflict with their beliefs. Other weaknesses include the lack of energy expertise in the media, the unwillingness of the public to engage in the policy process and the impotence of Parliamentary Committees. - Highlights: •Britain's nuclear power policy is failing due to high costs and problems of finance. •This has implications for European countries who want to use the same financing model. •The continued pursuit of a failing policy is due to poor advice from civil servants. •Lack of expertise in the media and lack of public engagement have contributed. •Parliamentary processes have not provided proper critical scrutiny.

  20. ALTERNATIVE METHODOLOGIES FOR THE ESTIMATION OF LOCAL POINT DENSITY INDEX: MOVING TOWARDS ADAPTIVE LIDAR DATA PROCESSING

    Directory of Open Access Journals (Sweden)

    Z. Lari

    2012-07-01

    Full Text Available Over the past few years, LiDAR systems have been established as a leading technology for the acquisition of high density point clouds over physical surfaces. These point clouds will be processed for the extraction of geo-spatial information. Local point density is one of the most important properties of the point cloud that highly affects the performance of data processing techniques and the quality of extracted information from these data. Therefore, it is necessary to define a standard methodology for the estimation of local point density indices to be considered for the precise processing of LiDAR data. Current definitions of local point density indices, which only consider the 2D neighbourhood of individual points, are not appropriate for 3D LiDAR data and cannot be applied for laser scans from different platforms. In order to resolve the drawbacks of these methods, this paper proposes several approaches for the estimation of the local point density index which take the 3D relationship among the points and the physical properties of the surfaces they belong to into account. In the simplest approach, an approximate value of the local point density for each point is defined while considering the 3D relationship among the points. In the other approaches, the local point density is estimated by considering the 3D neighbourhood of the point in question and the physical properties of the surface which encloses this point. The physical properties of the surfaces enclosing the LiDAR points are assessed through eigen-value analysis of the 3D neighbourhood of individual points and adaptive cylinder methods. This paper will discuss these approaches and highlight their impact on various LiDAR data processing activities (i.e., neighbourhood definition, region growing, segmentation, boundary detection, and classification. Experimental results from airborne and terrestrial LiDAR data verify the efficacy of considering local point density variation for

  1. Quantum entanglement and geometry of determinantal varieties

    International Nuclear Information System (INIS)

    Chen Hao

    2006-01-01

    Quantum entanglement was first recognized as a feature of quantum mechanics in the famous paper of Einstein, Podolsky, and Rosen. Recently it has been realized that quantum entanglement is a key ingredient in quantum computation, quantum communication, and quantum cryptography. In this paper, we introduce algebraic sets, which are determinantal varieties in the complex projective spaces or the products of complex projective spaces, for the mixed states on bipartite or multipartite quantum systems as their invariants under local unitary transformations. These invariants are naturally arised from the physical consideration of measuring mixed states by separable pure states. Our construction has applications in the following important topics in quantum information theory: (1) separability criterion, it is proved that the algebraic sets must be a union of the linear subspaces if the mixed states are separable; (2) simulation of Hamiltonians, it is proved that the simulation of semipositive Hamiltonians of the same rank implies the projective isomorphisms of the corresponding algebraic sets; (3) construction of bound entangled mixed states, examples of the entangled mixed states which are invariant under partial transpositions (thus PPT bound entanglement) are constructed systematically from our new separability criterion

  2. Development and evaluation of spatial point process models for epidermal nerve fibers.

    Science.gov (United States)

    Olsbo, Viktor; Myllymäki, Mari; Waller, Lance A; Särkkä, Aila

    2013-06-01

    We propose two spatial point process models for the spatial structure of epidermal nerve fibers (ENFs) across human skin. The models derive from two point processes, Φb and Φe, describing the locations of the base and end points of the fibers. Each point of Φe (the end point process) is connected to a unique point in Φb (the base point process). In the first model, both Φe and Φb are Poisson processes, yielding a null model of uniform coverage of the skin by end points and general baseline results and reference values for moments of key physiologic indicators. The second model provides a mechanistic model to generate end points for each base, and we model the branching structure more directly by defining Φe as a cluster process conditioned on the realization of Φb as its parent points. In both cases, we derive distributional properties for observable quantities of direct interest to neurologists such as the number of fibers per base, and the direction and range of fibers on the skin. We contrast both models by fitting them to data from skin blister biopsy images of ENFs and provide inference regarding physiological properties of ENFs. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Critical Control Points in the Processing of Cassava Tuber for Ighu ...

    African Journals Online (AJOL)

    Determination of the critical control points in the processing of cassava tuber into Ighu was carried out. The critical control points were determined according to the Codex guidelines for the application of the HACCP system by conducting hazard analysis. Hazard analysis involved proper examination of each processing step ...

  4. Distinguishing different types of inhomogeneity in Neyman-Scott point processes

    Czech Academy of Sciences Publication Activity Database

    Mrkvička, Tomáš

    2014-01-01

    Roč. 16, č. 2 (2014), s. 385-395 ISSN 1387-5841 Institutional support: RVO:60077344 Keywords : clustering * growing clusters * inhomogeneous cluster centers * inhomogeneous point process * location dependent scaling * Neyman-Scott point process Subject RIV: BA - General Mathematics Impact factor: 0.913, year: 2014

  5. The importance of topographically corrected null models for analyzing ecological point processes.

    Science.gov (United States)

    McDowall, Philip; Lynch, Heather J

    2017-07-01

    Analyses of point process patterns and related techniques (e.g., MaxEnt) make use of the expected number of occurrences per unit area and second-order statistics based on the distance between occurrences. Ecologists working with point process data often assume that points exist on a two-dimensional x-y plane or within a three-dimensional volume, when in fact many observed point patterns are generated on a two-dimensional surface existing within three-dimensional space. For many surfaces, however, such as the topography of landscapes, the projection from the surface to the x-y plane preserves neither area nor distance. As such, when these point patterns are implicitly projected to and analyzed in the x-y plane, our expectations of the point pattern's statistical properties may not be met. When used in hypothesis testing, we find that the failure to account for the topography of the generating surface may bias statistical tests that incorrectly identify clustering and, furthermore, may bias coefficients in inhomogeneous point process models that incorporate slope as a covariate. We demonstrate the circumstances under which this bias is significant, and present simple methods that allow point processes to be simulated with corrections for topography. These point patterns can then be used to generate "topographically corrected" null models against which observed point processes can be compared. © 2017 by the Ecological Society of America.

  6. Novel evaluation metrics for sparse spatio-temporal point process hotspot predictions - a crime case study

    OpenAIRE

    Adepeju, M.; Rosser, G.; Cheng, T.

    2016-01-01

    Many physical and sociological processes are represented as discrete events in time and space. These spatio-temporal point processes are often sparse, meaning that they cannot be aggregated and treated with conventional regression models. Models based on the point process framework may be employed instead for prediction purposes. Evaluating the predictive performance of these models poses a unique challenge, as the same sparseness prevents the use of popular measures such as the root mean squ...

  7. Efficient point cloud data processing in shipbuilding: Reformative component extraction method and registration method

    Directory of Open Access Journals (Sweden)

    Jingyu Sun

    2014-07-01

    Full Text Available To survive in the current shipbuilding industry, it is of vital importance for shipyards to have the ship components’ accuracy evaluated efficiently during most of the manufacturing steps. Evaluating components’ accuracy by comparing each component’s point cloud data scanned by laser scanners and the ship’s design data formatted in CAD cannot be processed efficiently when (1 extract components from point cloud data include irregular obstacles endogenously, or when (2 registration of the two data sets have no clear direction setting. This paper presents reformative point cloud data processing methods to solve these problems. K-d tree construction of the point cloud data fastens a neighbor searching of each point. Region growing method performed on the neighbor points of the seed point extracts the continuous part of the component, while curved surface fitting and B-spline curved line fitting at the edge of the continuous part recognize the neighbor domains of the same component divided by obstacles’ shadows. The ICP (Iterative Closest Point algorithm conducts a registration of the two sets of data after the proper registration’s direction is decided by principal component analysis. By experiments conducted at the shipyard, 200 curved shell plates are extracted from the scanned point cloud data, and registrations are conducted between them and the designed CAD data using the proposed methods for an accuracy evaluation. Results show that the methods proposed in this paper support the accuracy evaluation targeted point cloud data processing efficiently in practice.

  8. Edit distance for marked point processes revisited: An implementation by binary integer programming

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Yoshito; Aihara, Kazuyuki [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2015-12-15

    We implement the edit distance for marked point processes [Suzuki et al., Int. J. Bifurcation Chaos 20, 3699–3708 (2010)] as a binary integer program. Compared with the previous implementation using minimum cost perfect matching, the proposed implementation has two advantages: first, by using the proposed implementation, we can apply a wide variety of software and hardware, even spin glasses and coherent ising machines, to calculate the edit distance for marked point processes; second, the proposed implementation runs faster than the previous implementation when the difference between the numbers of events in two time windows for a marked point process is large.

  9. The cylindrical K-function and Poisson line cluster point processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Safavimanesh, Farzaneh; Rasmussen, Jakob G.

    Poisson line cluster point processes, is also introduced. Parameter estimation based on moment methods or Bayesian inference for this model is discussed when the underlying Poisson line process and the cluster memberships are treated as hidden processes. To illustrate the methodologies, we analyze two...

  10. Bridging the gap between a stationary point process and its Palm distribution

    NARCIS (Netherlands)

    Nieuwenhuis, G.

    1994-01-01

    In the context of stationary point processes measurements are usually made from a time point chosen at random or from an occurrence chosen at random. That is, either the stationary distribution P or its Palm distribution P° is the ruling probability measure. In this paper an approach is presented to

  11. Hierarchical spatial point process analysis for a plant community with high biodiversity

    DEFF Research Database (Denmark)

    Illian, Janine B.; Møller, Jesper; Waagepetersen, Rasmus

    2009-01-01

    A complex multivariate spatial point pattern of a plant community with high biodiversity is modelled using a hierarchical multivariate point process model. In the model, interactions between plants with different post-fire regeneration strategies are of key interest. We consider initially a maxim...

  12. Definition of distance for nonlinear time series analysis of marked point process data

    Energy Technology Data Exchange (ETDEWEB)

    Iwayama, Koji, E-mail: koji@sat.t.u-tokyo.ac.jp [Research Institute for Food and Agriculture, Ryukoku Univeristy, 1-5 Yokotani, Seta Oe-cho, Otsu-Shi, Shiga 520-2194 (Japan); Hirata, Yoshito; Aihara, Kazuyuki [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2017-01-30

    Marked point process data are time series of discrete events accompanied with some values, such as economic trades, earthquakes, and lightnings. A distance for marked point process data allows us to apply nonlinear time series analysis to such data. We propose a distance for marked point process data which can be calculated much faster than the existing distance when the number of marks is small. Furthermore, under some assumptions, the Kullback–Leibler divergences between posterior distributions for neighbors defined by this distance are small. We performed some numerical simulations showing that analysis based on the proposed distance is effective. - Highlights: • A new distance for marked point process data is proposed. • The distance can be computed fast enough for a small number of marks. • The method to optimize parameter values of the distance is also proposed. • Numerical simulations indicate that the analysis based on the distance is effective.

  13. Process and results of analytical framework and typology development for POINT

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik; Lehtonen, Markku; Bauler, Tom

    2009-01-01

    POINT is a project about how indicators are used in practice; to what extent and in what way indicators actually influence, support, or hinder policy and decision making processes, and what could be done to enhance the positive role of indicators in such processes. The project needs an analytical......, a set of core concepts and associated typologies, a series of analytic schemes proposed, and a number of research propositions and questions for the subsequent empirical work in POINT....

  14. Spatial Mixture Modelling for Unobserved Point Processes: Examples in Immunofluorescence Histology.

    Science.gov (United States)

    Ji, Chunlin; Merl, Daniel; Kepler, Thomas B; West, Mike

    2009-12-04

    We discuss Bayesian modelling and computational methods in analysis of indirectly observed spatial point processes. The context involves noisy measurements on an underlying point process that provide indirect and noisy data on locations of point outcomes. We are interested in problems in which the spatial intensity function may be highly heterogenous, and so is modelled via flexible nonparametric Bayesian mixture models. Analysis aims to estimate the underlying intensity function and the abundance of realized but unobserved points. Our motivating applications involve immunological studies of multiple fluorescent intensity images in sections of lymphatic tissue where the point processes represent geographical configurations of cells. We are interested in estimating intensity functions and cell abundance for each of a series of such data sets to facilitate comparisons of outcomes at different times and with respect to differing experimental conditions. The analysis is heavily computational, utilizing recently introduced MCMC approaches for spatial point process mixtures and extending them to the broader new context here of unobserved outcomes. Further, our example applications are problems in which the individual objects of interest are not simply points, but rather small groups of pixels; this implies a need to work at an aggregate pixel region level and we develop the resulting novel methodology for this. Two examples with with immunofluorescence histology data demonstrate the models and computational methodology.

  15. Some determinantal inequalities for Hadamard and Fan products of matrices

    Directory of Open Access Journals (Sweden)

    Xiaohui Fu

    2016-10-01

    Full Text Available Abstract In this note, we generalize some determinantal inequalities which are due to Lynn (Proc. Camb. Philos. 60:425-431, 1964, Chen (Linear Algebra Appl. 368:99-106, 2003 and Ando (Linear Multilinear Algebra 8:291-316, 1980.

  16. Characterization results and Markov chain Monte Carlo algorithms including exact simulation for some spatial point processes

    DEFF Research Database (Denmark)

    Häggström, Olle; Lieshout, Marie-Colette van; Møller, Jesper

    1999-01-01

    The area-interaction process and the continuum random-cluster model are characterized in terms of certain functional forms of their respective conditional intensities. In certain cases, these two point process models can be derived from a bivariate point process model which in many respects...... is simpler to analyse and simulate. Using this correspondence we devise a two-component Gibbs sampler, which can be used for fast and exact simulation by extending the recent ideas of Propp and Wilson. We further introduce a Swendsen-Wang type algorithm. The relevance of the results within spatial statistics...

  17. SINGLE TREE DETECTION FROM AIRBORNE LASER SCANNING DATA USING A MARKED POINT PROCESS BASED METHOD

    Directory of Open Access Journals (Sweden)

    J. Zhang

    2013-05-01

    Full Text Available Tree detection and reconstruction is of great interest in large-scale city modelling. In this paper, we present a marked point process model to detect single trees from airborne laser scanning (ALS data. We consider single trees in ALS recovered canopy height model (CHM as a realization of point process of circles. Unlike traditional marked point process, we sample the model in a constraint configuration space by making use of image process techniques. A Gibbs energy is defined on the model, containing a data term which judge the fitness of the model with respect to the data, and prior term which incorporate the prior knowledge of object layouts. We search the optimal configuration through a steepest gradient descent algorithm. The presented hybrid framework was test on three forest plots and experiments show the effectiveness of the proposed method.

  18. Second-order analysis of structured inhomogeneous spatio-temporal point processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Ghorbani, Mohammad

    Statistical methodology for spatio-temporal point processes is in its infancy. We consider second-order analysis based on pair correlation functions and K-functions for first general inhomogeneous spatio-temporal point processes and second inhomogeneous spatio-temporal Cox processes. Assuming...... spatio-temporal separability of the intensity function, we clarify different meanings of second-order spatio-temporal separability. One is second-order spatio-temporal independence and relates e.g. to log-Gaussian Cox processes with an additive covariance structure of the underlying spatio......-temporal Gaussian process. Another concerns shot-noise Cox processes with a separable spatio-temporal covariance density. We propose diagnostic procedures for checking hypotheses of second-order spatio-temporal separability, which we apply on simulated and real data (the UK 2001 epidemic foot and mouth disease data)....

  19. From point process observations to collective neural dynamics: Nonlinear Hawkes process GLMs, low-dimensional dynamics and coarse graining.

    Science.gov (United States)

    Truccolo, Wilson

    2016-11-01

    This review presents a perspective on capturing collective dynamics in recorded neuronal ensembles based on multivariate point process models, inference of low-dimensional dynamics and coarse graining of spatiotemporal measurements. A general probabilistic framework for continuous time point processes reviewed, with an emphasis on multivariate nonlinear Hawkes processes with exogenous inputs. A point process generalized linear model (PP-GLM) framework for the estimation of discrete time multivariate nonlinear Hawkes processes is described. The approach is illustrated with the modeling of collective dynamics in neocortical neuronal ensembles recorded in human and non-human primates, and prediction of single-neuron spiking. A complementary approach to capture collective dynamics based on low-dimensional dynamics ("order parameters") inferred via latent state-space models with point process observations is presented. The approach is illustrated by inferring and decoding low-dimensional dynamics in primate motor cortex during naturalistic reach and grasp movements. Finally, we briefly review hypothesis tests based on conditional inference and spatiotemporal coarse graining for assessing collective dynamics in recorded neuronal ensembles. Published by Elsevier Ltd.

  20. Determination of the impact of RGB points cloud attribute quality on color-based segmentation process

    Directory of Open Access Journals (Sweden)

    Bartłomiej Kraszewski

    2015-06-01

    Full Text Available The article presents the results of research on the effect that radiometric quality of point cloud RGB attributes have on color-based segmentation. In the research, a point cloud with a resolution of 5 mm, received from FAROARO Photon 120 scanner, described the fragment of an office’s room and color images were taken by various digital cameras. The images were acquired by SLR Nikon D3X, and SLR Canon D200 integrated with the laser scanner, compact camera Panasonic TZ-30 and a mobile phone digital camera. Color information from images was spatially related to point cloud in FAROARO Scene software. The color-based segmentation of testing data was performed with the use of a developed application named “RGB Segmentation”. The application was based on public Point Cloud Libraries (PCL and allowed to extract subsets of points fulfilling the criteria of segmentation from the source point cloud using region growing method.Using the developed application, the segmentation of four tested point clouds containing different RGB attributes from various images was performed. Evaluation of segmentation process was performed based on comparison of segments acquired using the developed application and extracted manually by an operator. The following items were compared: the number of obtained segments, the number of correctly identified objects and the correctness of segmentation process. The best correctness of segmentation and most identified objects were obtained using the data with RGB attribute from Nikon D3X images. Based on the results it was found that quality of RGB attributes of point cloud had impact only on the number of identified objects. In case of correctness of the segmentation, as well as its error no apparent relationship between the quality of color information and the result of the process was found.[b]Keywords[/b]: terrestrial laser scanning, color-based segmentation, RGB attribute, region growing method, digital images, points cloud

  1. Probabilistic safety assessment and optimal control of hazardous technological systems. A marked point process approach

    International Nuclear Information System (INIS)

    Holmberg, J.

    1997-04-01

    The thesis models risk management as an optimal control problem for a stochastic process. The approach classes the decisions made by management into three categories according to the control methods of a point process: (1) planned process lifetime, (2) modification of the design, and (3) operational decisions. The approach is used for optimization of plant shutdown criteria and surveillance test strategies of a hypothetical nuclear power plant

  2. Probabilistic safety assessment and optimal control of hazardous technological systems. A marked point process approach

    Energy Technology Data Exchange (ETDEWEB)

    Holmberg, J [VTT Automation, Espoo (Finland)

    1997-04-01

    The thesis models risk management as an optimal control problem for a stochastic process. The approach classes the decisions made by management into three categories according to the control methods of a point process: (1) planned process lifetime, (2) modification of the design, and (3) operational decisions. The approach is used for optimization of plant shutdown criteria and surveillance test strategies of a hypothetical nuclear power plant. 62 refs. The thesis includes also five previous publications by author.

  3. Apparatus and method for implementing power saving techniques when processing floating point values

    Science.gov (United States)

    Kim, Young Moon; Park, Sang Phill

    2017-10-03

    An apparatus and method are described for reducing power when reading and writing graphics data. For example, one embodiment of an apparatus comprises: a graphics processor unit (GPU) to process graphics data including floating point data; a set of registers, at least one of the registers of the set partitioned to store the floating point data; and encode/decode logic to reduce a number of binary 1 values being read from the at least one register by causing a specified set of bit positions within the floating point data to be read out as 0s rather than 1s.

  4. Effect of processing conditions on oil point pressure of moringa oleifera seed.

    Science.gov (United States)

    Aviara, N A; Musa, W B; Owolarafe, O K; Ogunsina, B S; Oluwole, F A

    2015-07-01

    Seed oil expression is an important economic venture in rural Nigeria. The traditional techniques of carrying out the operation is not only energy sapping and time consuming but also wasteful. In order to reduce the tedium involved in the expression of oil from moringa oleifera seed and develop efficient equipment for carrying out the operation, the oil point pressure of the seed was determined under different processing conditions using a laboratory press. The processing conditions employed were moisture content (4.78, 6.00, 8.00 and 10.00 % wet basis), heating temperature (50, 70, 85 and 100 °C) and heating time (15, 20, 25 and 30 min). Results showed that the oil point pressure increased with increase in seed moisture content, but decreased with increase in heating temperature and heating time within the above ranges. Highest oil point pressure value of 1.1239 MPa was obtained at the processing conditions of 10.00 % moisture content, 50 °C heating temperature and 15 min heating time. The lowest oil point pressure obtained was 0.3164 MPa and it occurred at the moisture content of 4.78 %, heating temperature of 100 °C and heating time of 30 min. Analysis of Variance (ANOVA) showed that all the processing variables and their interactions had significant effect on the oil point pressure of moringa oleifera seed at 1 % level of significance. This was further demonstrated using Response Surface Methodology (RSM). Tukey's test and Duncan's Multiple Range Analysis successfully separated the means and a multiple regression equation was used to express the relationship existing between the oil point pressure of moringa oleifera seed and its moisture content, processing temperature, heating time and their interactions. The model yielded coefficients that enabled the oil point pressure of the seed to be predicted with very high coefficient of determination.

  5. Linear and quadratic models of point process systems: contributions of patterned input to output.

    Science.gov (United States)

    Lindsay, K A; Rosenberg, J R

    2012-08-01

    In the 1880's Volterra characterised a nonlinear system using a functional series connecting continuous input and continuous output. Norbert Wiener, in the 1940's, circumvented problems associated with the application of Volterra series to physical problems by deriving from it a new series of terms that are mutually uncorrelated with respect to Gaussian processes. Subsequently, Brillinger, in the 1970's, introduced a point-process analogue of Volterra's series connecting point-process inputs to the instantaneous rate of point-process output. We derive here a new series from this analogue in which its terms are mutually uncorrelated with respect to Poisson processes. This new series expresses how patterned input in a spike train, represented by third-order cross-cumulants, is converted into the instantaneous rate of an output point-process. Given experimental records of suitable duration, the contribution of arbitrary patterned input to an output process can, in principle, be determined. Solutions for linear and quadratic point-process models with one and two inputs and a single output are investigated. Our theoretical results are applied to isolated muscle spindle data in which the spike trains from the primary and secondary endings from the same muscle spindle are recorded in response to stimulation of one and then two static fusimotor axons in the absence and presence of a random length change imposed on the parent muscle. For a fixed mean rate of input spikes, the analysis of the experimental data makes explicit which patterns of two input spikes contribute to an output spike. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Using a Virtual Experiment to Analyze Infiltration Process from Point to Grid-cell Size Scale

    Science.gov (United States)

    Barrios, M. I.

    2013-12-01

    The hydrological science requires the emergence of a consistent theoretical corpus driving the relationships between dominant physical processes at different spatial and temporal scales. However, the strong spatial heterogeneities and non-linearities of these processes make difficult the development of multiscale conceptualizations. Therefore, scaling understanding is a key issue to advance this science. This work is focused on the use of virtual experiments to address the scaling of vertical infiltration from a physically based model at point scale to a simplified physically meaningful modeling approach at grid-cell scale. Numerical simulations have the advantage of deal with a wide range of boundary and initial conditions against field experimentation. The aim of the work was to show the utility of numerical simulations to discover relationships between the hydrological parameters at both scales, and to use this synthetic experience as a media to teach the complex nature of this hydrological process. The Green-Ampt model was used to represent vertical infiltration at point scale; and a conceptual storage model was employed to simulate the infiltration process at the grid-cell scale. Lognormal and beta probability distribution functions were assumed to represent the heterogeneity of soil hydraulic parameters at point scale. The linkages between point scale parameters and the grid-cell scale parameters were established by inverse simulations based on the mass balance equation and the averaging of the flow at the point scale. Results have shown numerical stability issues for particular conditions and have revealed the complex nature of the non-linear relationships between models' parameters at both scales and indicate that the parameterization of point scale processes at the coarser scale is governed by the amplification of non-linear effects. The findings of these simulations have been used by the students to identify potential research questions on scale issues

  7. Putting to point the production process of iodine-131 by dry distillation (Preoperational tests)

    International Nuclear Information System (INIS)

    Alanis M, J.

    2002-12-01

    With the purpose of putting to point the process of production of 131 I, one of the objectives of carrying out the realization of operational tests of the production process of iodine-131, it was of verifying the operation of each one of the following components: heating systems, vacuum system, mechanical system and peripheral equipment that are part of the production process of iodine-131, another of the objectives, was settling down the optimal parameters that were applied in each process during the obtaining of iodine-131, it is necessary to point out that this objective is very important, since the components of the equipment are new and its behavior during the process is different to the equipment where its were carried out the experimental studies. (Author)

  8. Hazard analysis and critical control point (HACCP) for an ultrasound food processing operation.

    Science.gov (United States)

    Chemat, Farid; Hoarau, Nicolas

    2004-05-01

    Emerging technologies, such as ultrasound (US), used for food and drink production often cause hazards for product safety. Classical quality control methods are inadequate to control these hazards. Hazard analysis of critical control points (HACCP) is the most secure and cost-effective method for controlling possible product contamination or cross-contamination, due to physical or chemical hazard during production. The following case study on the application of HACCP to an US food-processing operation demonstrates how the hazards at the critical control points of the process are effectively controlled through the implementation of HACCP.

  9. The application of prototype point processes for the summary and description of California wildfires

    Science.gov (United States)

    Nichols, K.; Schoenberg, F.P.; Keeley, J.E.; Bray, A.; Diez, D.

    2011-01-01

    A method for summarizing repeated realizations of a space-time marked point process, known as prototyping, is discussed and applied to catalogues of wildfires in California. Prototype summaries are constructed for varying time intervals using California wildfire data from 1990 to 2006. Previous work on prototypes for temporal and space-time point processes is extended here to include methods for computing prototypes with marks and the incorporation of prototype summaries into hierarchical clustering algorithms, the latter of which is used to delineate fire seasons in California. Other results include summaries of patterns in the spatial-temporal distribution of wildfires within each wildfire season. ?? 2011 Blackwell Publishing Ltd.

  10. Mass measurement on the rp-process waiting point {sup 72}Kr

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, D. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Kolhinen, V.S. [Jyvaeskylae Univ. (Finland); Audi, G. [CSNSM-IN2P3-Centre National de la Recherche Scientifique (CNRS), 91 - Orsay (FR)] [and others

    2004-06-01

    The mass of one of the three major waiting points in the astrophysical rp-process {sup 72}Kr was measured for the first time with the Penning trap mass spectrometer ISOLTRAP. The measurement yielded a relative mass uncertainty of {delta}m/m=1.2 x 10{sup -7} ({delta}m=8 keV). Other Kr isotopes, also needed for astrophysical calculations, were measured with more than one order of magnitude improved accuracy. We use the ISOLTRAP masses of{sup 72-74}Kr to reanalyze the role of the {sup 72}Kr waiting point in the rp-process during X-ray bursts. (orig.)

  11. Efficient LIDAR Point Cloud Data Managing and Processing in a Hadoop-Based Distributed Framework

    Science.gov (United States)

    Wang, C.; Hu, F.; Sha, D.; Han, X.

    2017-10-01

    Light Detection and Ranging (LiDAR) is one of the most promising technologies in surveying and mapping city management, forestry, object recognition, computer vision engineer and others. However, it is challenging to efficiently storage, query and analyze the high-resolution 3D LiDAR data due to its volume and complexity. In order to improve the productivity of Lidar data processing, this study proposes a Hadoop-based framework to efficiently manage and process LiDAR data in a distributed and parallel manner, which takes advantage of Hadoop's storage and computing ability. At the same time, the Point Cloud Library (PCL), an open-source project for 2D/3D image and point cloud processing, is integrated with HDFS and MapReduce to conduct the Lidar data analysis algorithms provided by PCL in a parallel fashion. The experiment results show that the proposed framework can efficiently manage and process big LiDAR data.

  12. End point detection in ion milling processes by sputter-induced optical emission spectroscopy

    International Nuclear Information System (INIS)

    Lu, C.; Dorian, M.; Tabei, M.; Elsea, A.

    1984-01-01

    The characteristic optical emission from the sputtered material during ion milling processes can provide an unambiguous indication of the presence of the specific etched species. By monitoring the intensity of a representative emission line, the etching process can be precisely terminated at an interface. Enhancement of the etching end point is possible by using a dual-channel photodetection system operating in a ratio or difference mode. The installation of the optical detection system to an existing etching chamber has been greatly facilitated by the use of optical fibers. Using a commercial ion milling system, experimental data for a number of etching processes have been obtained. The result demonstrates that sputter-induced optical emission spectroscopy offers many advantages over other techniques in detecting the etching end point of ion milling processes

  13. Digital analyzer for point processes based on first-in-first-out memories

    Science.gov (United States)

    Basano, Lorenzo; Ottonello, Pasquale; Schiavi, Enore

    1992-06-01

    We present an entirely new version of a multipurpose instrument designed for the statistical analysis of point processes, especially those characterized by high bunching. A long sequence of pulses can be recorded in the RAM bank of a personal computer via a suitably designed front end which employs a pair of first-in-first-out (FIFO) memories; these allow one to build an analyzer that, besides being simpler from the electronic point of view, is capable of sustaining much higher intensity fluctuations of the point process. The overflow risk of the device is evaluated by treating the FIFO pair as a queueing system. The apparatus was tested using both a deterministic signal and a sequence of photoelectrons obtained from laser light scattered by random surfaces.

  14. ON THE ESTIMATION OF DISTANCE DISTRIBUTION FUNCTIONS FOR POINT PROCESSES AND RANDOM SETS

    Directory of Open Access Journals (Sweden)

    Dietrich Stoyan

    2011-05-01

    Full Text Available This paper discusses various estimators for the nearest neighbour distance distribution function D of a stationary point process and for the quadratic contact distribution function Hq of a stationary random closed set. It recommends the use of Hanisch's estimator of D, which is of Horvitz-Thompson type, and the minussampling estimator of Hq. This recommendation is based on simulations for Poisson processes and Boolean models.

  15. Analysis of the stochastic channel model by Saleh & Valenzuela via the theory of point processes

    DEFF Research Database (Denmark)

    Jakobsen, Morten Lomholt; Pedersen, Troels; Fleury, Bernard Henri

    2012-01-01

    and underlying features, like the intensity function of the component delays and the delaypower intensity. The flexibility and clarity of the mathematical instruments utilized to obtain these results lead us to conjecture that the theory of spatial point processes provides a unifying mathematical framework...

  16. AKaplan-Meier estimators of distance distributions for spatial point processes

    NARCIS (Netherlands)

    Baddeley, A.J.; Gill, R.D.

    1997-01-01

    When a spatial point process is observed through a bounded window, edge effects hamper the estimation of characteristics such as the empty space function $F$, the nearest neighbour distance distribution $G$, and the reduced second order moment function $K$. Here we propose and study product-limit

  17. Two step estimation for Neyman-Scott point process with inhomogeneous cluster centers

    Czech Academy of Sciences Publication Activity Database

    Mrkvička, T.; Muška, Milan; Kubečka, Jan

    2014-01-01

    Roč. 24, č. 1 (2014), s. 91-100 ISSN 0960-3174 R&D Projects: GA ČR(CZ) GA206/07/1392 Institutional support: RVO:60077344 Keywords : bayesian method * clustering * inhomogeneous point process Subject RIV: EH - Ecology, Behaviour Impact factor: 1.623, year: 2014

  18. Dense range images from sparse point clouds using multi-scale processing

    NARCIS (Netherlands)

    Do, Q.L.; Ma, L.; With, de P.H.N.

    2013-01-01

    Multi-modal data processing based on visual and depth/range images has become relevant in computer vision for 3D reconstruction applications such as city modeling, robot navigation etc. In this paper, we generate highaccuracy dense range images from sparse point clouds to facilitate such

  19. Fast covariance estimation for innovations computed from a spatial Gibbs point process

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Rubak, Ege

    In this paper, we derive an exact formula for the covariance of two innovations computed from a spatial Gibbs point process and suggest a fast method for estimating this covariance. We show how this methodology can be used to estimate the asymptotic covariance matrix of the maximum pseudo...

  20. A Systematic Approach to Process Evaluation in the Central Oklahoma Turning Point (COTP) Partnership

    Science.gov (United States)

    Tolma, Eleni L.; Cheney, Marshall K.; Chrislip, David D.; Blankenship, Derek; Troup, Pam; Hann, Neil

    2011-01-01

    Formation is an important stage of partnership development. Purpose: To describe the systematic approach to process evaluation of a Turning Point initiative in central Oklahoma during the formation stage. The nine-month collaborative effort aimed to develop an action plan to promote health. Methods: A sound planning framework was used in the…

  1. Áreas de polígonos via determinantes

    OpenAIRE

    Zerbinatti, Paulo Henrique [UNESP

    2015-01-01

    The aim of this work is to present a study on areas of polygons through their vertex coordinates. We treat the subject using determinants of order 2 and basic Euclidean Geometry O objetivo deste trabalho e apresentar um estudo sobre o c alculo de areas de pol gonos atrav es das coordenadas de seus v ertices. Faremos isto utilizando determinantes de ordem 2 e conceitos b asicos de Geometria Euclidiana Plana

  2. Determinantes sociales de la salud y el trabajo informal

    OpenAIRE

    Consuelo Vélez Álvarez; María del Pilar Escobar Potes; María Eugenia Pico Merchán

    2013-01-01

    Objetivo: Describir elementos teóricos sobre los determinantes sociales de la salud en la población trabajadora informal y condiciones sociales, modos de vida y repercusiones en el proceso salud-enfermedad. Estrategia de búsqueda: Búsqueda sistemática en bases de datos especializadas (Ovid, Proquest, Hinary, Medline, LILACS, Literatura gris). Se utilizaron las siguientes palabras claves: condiciones sociales, factores socioeconómicos, fuerza de trabajo, empleo; de igual forma se retoman texto...

  3. A Combined Control Chart for Identifying Out–Of–Control Points in Multivariate Processes

    Directory of Open Access Journals (Sweden)

    Marroquín–Prado E.

    2010-10-01

    Full Text Available The Hotelling's T2 control chart is widely used to identify out–of–control signals in multivariate processes. However, this chart is not sensitive to small shifts in the process mean vec tor. In this work we propose a control chart to identify out–of–control signals. The proposed chart is a combination of Hotelling's T2 chart, M chart proposed by Hayter et al. (1994 and a new chart based on Principal Components. The combination of these charts identifies any type and size of change in the process mean vector. Us ing simulation and the Average Run Length (ARL, the performance of the proposed control chart is evaluated. The ARL means the average points within control before an out–of–control point is detected, The results of the simulation show that the proposed chart is more sensitive that each one of the three charts individually

  4. Steam generators secondary side chemical cleaning at Point Lepreau using the Siemen's high temperature process

    International Nuclear Information System (INIS)

    Verma, K.; MacNeil, C.; Odar, S.

    1996-01-01

    The secondary sides of all four steam generators at the Point Lepreau Nuclear Generating Stations were cleaned during the 1995 annual outage run-down using the Siemens high temperature chemical cleaning process. Traditionally all secondary side chemical cleaning exercises in CANDU as well as the other nuclear power stations in North America have been conducted using a process developed in conjunction with the Electric Power Research Institute (EPRI). The Siemens high temperature process was applied for the first time in North America at the Point Lepreau Nuclear Generating Station (PLGS). The paper discusses experiences related to the pre and post award chemical cleaning activities, chemical cleaning application, post cleaning inspection results and waste handling activities. (author)

  5. Bayesian inference for multivariate point processes observed at sparsely distributed times

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl; Møller, Jesper; Aukema, B.H.

    We consider statistical and computational aspects of simulation-based Bayesian inference for a multivariate point process which is only observed at sparsely distributed times. For specicity we consider a particular data set which has earlier been analyzed by a discrete time model involving unknown...... normalizing constants. We discuss the advantages and disadvantages of using continuous time processes compared to discrete time processes in the setting of the present paper as well as other spatial-temporal situations. Keywords: Bark beetle, conditional intensity, forest entomology, Markov chain Monte Carlo...

  6. The Oil Point Method - A tool for indicative environmental evaluation in material and process selection

    DEFF Research Database (Denmark)

    Bey, Niki

    2000-01-01

    to three essential assessment steps, the method enables rough environmental evaluations and supports in this way material- and process-related decision-making in the early stages of design. In its overall structure, the Oil Point Method is related to Life Cycle Assessment - except for two main differences...... of environmental evaluation and only approximate information about the product and its life cycle. This dissertation addresses this challenge in presenting a method, which is tailored to these requirements of designers - the Oil Point Method (OPM). In providing environmental key information and confining itself...

  7. Spatial point process analysis for a plant community with high biodiversity

    DEFF Research Database (Denmark)

    Illian, Janine; Møller, Jesper; Waagepetersen, Rasmus Plenge

    A complex multivariate spatial point pattern for a plant community with high biodiversity is modelled using a hierarchical multivariate point process model. In the model, interactions between plants with different post-fire regeneration strategies are of key interest. We consider initially...... a maximum likelihood approach to inference where problems arise due to unknown interaction radii for the plants. We next demonstrate that a Bayesian approach provides a flexible framework for incorporating prior information concerning the interaction radii. From an ecological perspective, we are able both...

  8. Analysis of residual stress state in sheet metal parts processed by single point incremental forming

    Science.gov (United States)

    Maaß, F.; Gies, S.; Dobecki, M.; Brömmelhoff, K.; Tekkaya, A. E.; Reimers, W.

    2018-05-01

    The mechanical properties of formed metal components are highly affected by the prevailing residual stress state. A selective induction of residual compressive stresses in the component, can improve the product properties such as the fatigue strength. By means of single point incremental forming (SPIF), the residual stress state can be influenced by adjusting the process parameters during the manufacturing process. To achieve a fundamental understanding of the residual stress formation caused by the SPIF process, a valid numerical process model is essential. Within the scope of this paper the significance of kinematic hardening effects on the determined residual stress state is presented based on numerical simulations. The effect of the unclamping step after the manufacturing process is also analyzed. An average deviation of the residual stress amplitudes in the clamped and unclamped condition of 18 % reveals, that the unclamping step needs to be considered to reach a high numerical prediction quality.

  9. Analysis of multi-species point patterns using multivariate log Gaussian Cox processes

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus; Guan, Yongtao; Jalilian, Abdollah

    Multivariate log Gaussian Cox processes are flexible models for multivariate point patterns. However, they have so far only been applied in bivariate cases. In this paper we move beyond the bivariate case in order to model multi-species point patterns of tree locations. In particular we address t...... of the data. The selected number of common latent fields provides an index of complexity of the multivariate covariance structure. Hierarchical clustering is used to identify groups of species with similar patterns of dependence on the common latent fields.......Multivariate log Gaussian Cox processes are flexible models for multivariate point patterns. However, they have so far only been applied in bivariate cases. In this paper we move beyond the bivariate case in order to model multi-species point patterns of tree locations. In particular we address...... the problems of identifying parsimonious models and of extracting biologically relevant information from the fitted models. The latent multivariate Gaussian field is decomposed into components given in terms of random fields common to all species and components which are species specific. This allows...

  10. Prospects for direct neutron capture measurements on s-process branching point isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, C.; Lerendegui-Marco, J.; Quesada, J.M. [Universidad de Sevilla, Dept. de Fisica Atomica, Molecular y Nuclear, Sevilla (Spain); Domingo-Pardo, C. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Kaeppeler, F. [Karlsruhe Institute of Technology, Institut fuer Kernphysik, Karlsruhe (Germany); Palomo, F.R. [Universidad de Sevilla, Dept. de Ingenieria Electronica, Sevilla (Spain); Reifarth, R. [Goethe-Universitaet Frankfurt am Main, Frankfurt am Main (Germany)

    2017-05-15

    The neutron capture cross sections of several unstable key isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure directly due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n, γ) measurement, where high neutron fluxes and effective background rejection capabilities are required. At present there are about 21 relevant s-process branching point isotopes whose cross section could not be measured yet over the neutron energy range of interest for astrophysics. However, the situation is changing with some very recent developments and upcoming technologies. This work introduces three techniques that will change the current paradigm in the field: the use of γ-ray imaging techniques in (n, γ) experiments, the production of moderated neutron beams using high-power lasers, and double capture experiments in Maxwellian neutron beams. (orig.)

  11. Instantaneous nonlinear assessment of complex cardiovascular dynamics by Laguerre-Volterra point process models.

    Science.gov (United States)

    Valenza, Gaetano; Citi, Luca; Barbieri, Riccardo

    2013-01-01

    We report an exemplary study of instantaneous assessment of cardiovascular dynamics performed using point-process nonlinear models based on Laguerre expansion of the linear and nonlinear Wiener-Volterra kernels. As quantifiers, instantaneous measures such as high order spectral features and Lyapunov exponents can be estimated from a quadratic and cubic autoregressive formulation of the model first order moment, respectively. Here, these measures are evaluated on heartbeat series coming from 16 healthy subjects and 14 patients with Congestive Hearth Failure (CHF). Data were gathered from the on-line repository PhysioBank, which has been taken as landmark for testing nonlinear indices. Results show that the proposed nonlinear Laguerre-Volterra point-process methods are able to track the nonlinear and complex cardiovascular dynamics, distinguishing significantly between CHF and healthy heartbeat series.

  12. MODELLING AND SIMULATION OF A NEUROPHYSIOLOGICAL EXPERIMENT BY SPATIO-TEMPORAL POINT PROCESSES

    Directory of Open Access Journals (Sweden)

    Viktor Beneš

    2011-05-01

    Full Text Available We present a stochastic model of an experimentmonitoring the spiking activity of a place cell of hippocampus of an experimental animal moving in an arena. Doubly stochastic spatio-temporal point process is used to model and quantify overdispersion. Stochastic intensity is modelled by a Lévy based random field while the animal path is simplified to a discrete random walk. In a simulation study first a method suggested previously is used. Then it is shown that a solution of the filtering problem yields the desired inference to the random intensity. Two approaches are suggested and the new one based on finite point process density is applied. Using Markov chain Monte Carlo we obtain numerical results from the simulated model. The methodology is discussed.

  13. Point process analyses of variations in smoking rate by setting, mood, gender, and dependence

    Science.gov (United States)

    Shiffman, Saul; Rathbun, Stephen L.

    2010-01-01

    The immediate emotional and situational antecedents of ad libitum smoking are still not well understood. We re-analyzed data from Ecological Momentary Assessment using novel point-process analyses, to assess how craving, mood, and social setting influence smoking rate, as well as assessing the moderating effects of gender and nicotine dependence. 304 smokers recorded craving, mood, and social setting using electronic diaries when smoking and at random nonsmoking times over 16 days of smoking. Point-process analysis, which makes use of the known random sampling scheme for momentary variables, examined main effects of setting and interactions with gender and dependence. Increased craving was associated with higher rates of smoking, particularly among women. Negative affect was not associated with smoking rate, even in interaction with arousal, but restlessness was associated with substantially higher smoking rates. Women's smoking tended to be less affected by negative affect. Nicotine dependence had little moderating effect on situational influences. Smoking rates were higher when smokers were alone or with others smoking, and smoking restrictions reduced smoking rates. However, the presence of others smoking undermined the effects of restrictions. The more sensitive point-process analyses confirmed earlier findings, including the surprising conclusion that negative affect by itself was not related to smoking rates. Contrary to hypothesis, men's and not women's smoking was influenced by negative affect. Both smoking restrictions and the presence of others who are not smoking suppress smoking, but others’ smoking undermines the effects of restrictions. Point-process analyses of EMA data can bring out even small influences on smoking rate. PMID:21480683

  14. A random point process model for the score in sport matches

    Czech Academy of Sciences Publication Activity Database

    Volf, Petr

    2009-01-01

    Roč. 20, č. 2 (2009), s. 121-131 ISSN 1471-678X R&D Projects: GA AV ČR(CZ) IAA101120604 Institutional research plan: CEZ:AV0Z10750506 Keywords : sport statistics * scoring intensity * Cox’s regression model Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2009/SI/volf-a random point process model for the score in sport matches.pdf

  15. A business process model as a starting point for tight cooperation among organizations

    Directory of Open Access Journals (Sweden)

    O. Mysliveček

    2006-01-01

    Full Text Available Outsourcing and other kinds of tight cooperation among organizations are more and more necessary for success on all markets (markets of high technology products are particularly influenced. Thus it is important for companies to be able to effectively set up all kinds of cooperation. A business process model (BPM is a suitable starting point for this future cooperation. In this paper the process of setting up such cooperation is outlined, as well as why it is important for business success. 

  16. Weak interaction rates for Kr and Sr waiting-point nuclei under rp-process conditions

    International Nuclear Information System (INIS)

    Sarriguren, P.

    2009-01-01

    Weak interaction rates are studied in neutron deficient Kr and Sr waiting-point isotopes in ranges of densities and temperatures relevant for the rp process. The nuclear structure is described within a microscopic model (deformed QRPA) that reproduces not only the half-lives but also the Gamow-Teller strength distributions recently measured. The various sensitivities of the decay rates to both density and temperature are discussed. Continuum electron capture is shown to contribute significantly to the weak rates at rp-process conditions.

  17. PARALLEL PROCESSING OF BIG POINT CLOUDS USING Z-ORDER-BASED PARTITIONING

    Directory of Open Access Journals (Sweden)

    C. Alis

    2016-06-01

    Full Text Available As laser scanning technology improves and costs are coming down, the amount of point cloud data being generated can be prohibitively difficult and expensive to process on a single machine. This data explosion is not only limited to point cloud data. Voluminous amounts of high-dimensionality and quickly accumulating data, collectively known as Big Data, such as those generated by social media, Internet of Things devices and commercial transactions, are becoming more prevalent as well. New computing paradigms and frameworks are being developed to efficiently handle the processing of Big Data, many of which utilize a compute cluster composed of several commodity grade machines to process chunks of data in parallel. A central concept in many of these frameworks is data locality. By its nature, Big Data is large enough that the entire dataset would not fit on the memory and hard drives of a single node hence replicating the entire dataset to each worker node is impractical. The data must then be partitioned across worker nodes in a manner that minimises data transfer across the network. This is a challenge for point cloud data because there exist different ways to partition data and they may require data transfer. We propose a partitioning based on Z-order which is a form of locality-sensitive hashing. The Z-order or Morton code is computed by dividing each dimension to form a grid then interleaving the binary representation of each dimension. For example, the Z-order code for the grid square with coordinates (x = 1 = 012, y = 3 = 112 is 10112 = 11. The number of points in each partition is controlled by the number of bits per dimension: the more bits, the fewer the points. The number of bits per dimension also controls the level of detail with more bits yielding finer partitioning. We present this partitioning method by implementing it on Apache Spark and investigating how different parameters affect the accuracy and running time of the k nearest

  18. Parallel Processing of Big Point Clouds Using Z-Order Partitioning

    Science.gov (United States)

    Alis, C.; Boehm, J.; Liu, K.

    2016-06-01

    As laser scanning technology improves and costs are coming down, the amount of point cloud data being generated can be prohibitively difficult and expensive to process on a single machine. This data explosion is not only limited to point cloud data. Voluminous amounts of high-dimensionality and quickly accumulating data, collectively known as Big Data, such as those generated by social media, Internet of Things devices and commercial transactions, are becoming more prevalent as well. New computing paradigms and frameworks are being developed to efficiently handle the processing of Big Data, many of which utilize a compute cluster composed of several commodity grade machines to process chunks of data in parallel. A central concept in many of these frameworks is data locality. By its nature, Big Data is large enough that the entire dataset would not fit on the memory and hard drives of a single node hence replicating the entire dataset to each worker node is impractical. The data must then be partitioned across worker nodes in a manner that minimises data transfer across the network. This is a challenge for point cloud data because there exist different ways to partition data and they may require data transfer. We propose a partitioning based on Z-order which is a form of locality-sensitive hashing. The Z-order or Morton code is computed by dividing each dimension to form a grid then interleaving the binary representation of each dimension. For example, the Z-order code for the grid square with coordinates (x = 1 = 012, y = 3 = 112) is 10112 = 11. The number of points in each partition is controlled by the number of bits per dimension: the more bits, the fewer the points. The number of bits per dimension also controls the level of detail with more bits yielding finer partitioning. We present this partitioning method by implementing it on Apache Spark and investigating how different parameters affect the accuracy and running time of the k nearest neighbour algorithm

  19. Developing a Business Intelligence Process for a Training Module in SharePoint 2010

    Science.gov (United States)

    Schmidtchen, Bryce; Solano, Wanda M.; Albasini, Colby

    2015-01-01

    Prior to this project, training information for the employees of the National Center for Critical Processing and Storage (NCCIPS) was stored in an array of unrelated spreadsheets and SharePoint lists that had to be manually updated. By developing a content management system through a web application platform named SharePoint, this training system is now highly automated and provides a much less intensive method of storing training data and scheduling training courses. This system was developed by using SharePoint Designer and laying out the data structure for the interaction between different lists of data about the employees. The automation of data population inside of the lists was accomplished by implementing SharePoint workflows which essentially lay out the logic for how data is connected and calculated between certain lists. The resulting training system is constructed from a combination of five lists of data with a single list acting as the user-friendly interface. This interface is populated with the courses required for each employee and includes past and future information about course requirements. The employees of NCCIPS now have the ability to view, log, and schedule their training information and courses with much more ease. This system will relieve a significant amount of manual input and serve as a powerful informational resource for the employees of NCCIPS in the future.

  20. EFFICIENT LIDAR POINT CLOUD DATA MANAGING AND PROCESSING IN A HADOOP-BASED DISTRIBUTED FRAMEWORK

    Directory of Open Access Journals (Sweden)

    C. Wang

    2017-10-01

    Full Text Available Light Detection and Ranging (LiDAR is one of the most promising technologies in surveying and mapping,city management, forestry, object recognition, computer vision engineer and others. However, it is challenging to efficiently storage, query and analyze the high-resolution 3D LiDAR data due to its volume and complexity. In order to improve the productivity of Lidar data processing, this study proposes a Hadoop-based framework to efficiently manage and process LiDAR data in a distributed and parallel manner, which takes advantage of Hadoop’s storage and computing ability. At the same time, the Point Cloud Library (PCL, an open-source project for 2D/3D image and point cloud processing, is integrated with HDFS and MapReduce to conduct the Lidar data analysis algorithms provided by PCL in a parallel fashion. The experiment results show that the proposed framework can efficiently manage and process big LiDAR data.

  1. Implementation of hazard analysis and critical control point (HACCP) in dried anchovy production process

    Science.gov (United States)

    Citraresmi, A. D. P.; Wahyuni, E. E.

    2018-03-01

    The aim of this study was to inspect the implementation of Hazard Analysis and Critical Control Point (HACCP) for identification and prevention of potential hazards in the production process of dried anchovy at PT. Kelola Mina Laut (KML), Lobuk unit, Sumenep. Cold storage process is needed in each anchovy processing step in order to maintain its physical and chemical condition. In addition, the implementation of quality assurance system should be undertaken to maintain product quality. The research was conducted using a survey method, by following the whole process of making anchovy from the receiving raw materials to the packaging of final product. The method of data analysis used was descriptive analysis method. Implementation of HACCP at PT. KML, Lobuk unit, Sumenep was conducted by applying Pre Requisite Programs (PRP) and preparation stage consisting of 5 initial stages and 7 principles of HACCP. The results showed that CCP was found in boiling process flow with significant hazard of Listeria monocytogenesis bacteria and final sorting process with significant hazard of foreign material contamination in the product. Actions taken were controlling boiling temperature of 100 – 105°C for 3 - 5 minutes and training for sorting process employees.

  2. Optimization of the single point incremental forming process for titanium sheets by using response surface

    Directory of Open Access Journals (Sweden)

    Saidi Badreddine

    2016-01-01

    Full Text Available The single point incremental forming process is well-known to be perfectly suited for prototyping and small series. One of its fields of applicability is the medicine area for the forming of titanium prostheses or titanium medical implants. However this process is not yet very industrialized, mainly due its geometrical inaccuracy, its not homogeneous thickness distribution& Moreover considerable forces can occur. They must be controlled in order to preserve the tooling. In this paper, a numerical approach is proposed in order to minimize the maximum force achieved during the incremental forming of titanium sheets and to maximize the minimal thickness. A surface response methodology is used to find the optimal values of two input parameters of the process, the punch diameter and the vertical step size of the tool path.

  3. Marked point process framework for living probabilistic safety assessment and risk follow-up

    International Nuclear Information System (INIS)

    Arjas, Elja; Holmberg, Jan

    1995-01-01

    We construct a model for living probabilistic safety assessment (PSA) by applying the general framework of marked point processes. The framework provides a theoretically rigorous approach for considering risk follow-up of posterior hazards. In risk follow-up, the hazard of core damage is evaluated synthetically at time points in the past, by using some observed events as logged history and combining it with re-evaluated potential hazards. There are several alternatives for doing this, of which we consider three here, calling them initiating event approach, hazard rate approach, and safety system approach. In addition, for a comparison, we consider a core damage hazard arising in risk monitoring. Each of these four definitions draws attention to a particular aspect in risk assessment, and this is reflected in the behaviour of the consequent risk importance measures. Several alternative measures are again considered. The concepts and definitions are illustrated by a numerical example

  4. Quality control for electron beam processing of polymeric materials by end-point analysis

    International Nuclear Information System (INIS)

    DeGraff, E.; McLaughlin, W.L.

    1981-01-01

    Properties of certain plastics, e.g. polytetrafluoroethylene, polyethylene, ethylene vinyl acetate copolymer, can be modified selectively by ionizing radiation. One of the advantages of this treatment over chemical methods is better control of the process and the end-product properties. The most convenient method of dosimetry for monitoring quality control is post-irradiation evaluation of the plastic itself, e.g., melt index and melt point determination. It is shown that by proper calibration in terms of total dose and sufficiently reproducible radiation effects, such product test methods provide convenient and meaningful analyses. Other appropriate standardized analytical methods include stress-crack resistance, stress-strain-to-fracture testing and solubility determination. Standard routine dosimetry over the dose and dose rate ranges of interest confirm that measured product end points can be correlated with calibrated values of absorbed dose in the product within uncertainty limits of the measurements. (author)

  5. Determinantes del ingreso y del gasto corriente de los hogares

    OpenAIRE

    Muñoz C., Manuel

    2004-01-01

    Este ensayo de investigación empírica analiza los determinantes del ingreso y del gasto en los hogares colombianos. Utilizando un modelo del ciclo de vida con datos de la encuesta de hogares de 1994 y 1995, muestra que el comportamiento del ingreso está afectado principalmente por las características demográficas del hogar y los rasgos socio ocupacionales de sus miembros. El comportamiento del gasto está determinado ante todo por el ingreso y, en menor medida, por las características sociales...

  6. Obesidad y Mercado de Trabajo: Factores Determinantes e Implicaciones

    OpenAIRE

    Benítez Llamazares, Nuria

    2016-01-01

    El sobrepeso y la obesidad se definen de acuerdo con la Organización Mundial de la Salud (OMS) como “una acumulación anormal o excesiva de grasa que puede ser perjudicial para la salud”. Ambos conceptos, sobrepeso y obesidad, son considerados factores determinantes de riesgo en la salud de la población y en las últimas décadas hemos visto cómo los porcentajes de población con sobrepeso y obesidad se han incrementado de forma alarmante, especialmente en los países desarrollados....

  7. Ahorro para el retiro en Colombia: patrones y determinantes

    OpenAIRE

    Guataquí, Juan; Rodríguez Acosta, Mauricio; Garcia-Suaza, Andres

    2009-01-01

    La decisión de los individuos acerca del ahorro para el retiro ha sido abordada teóricamente bajo la hipótesis de que el sistema de seguridad social se comporta como un sustituto de otros mecanismos de ahorro. Este documento presenta evidencia de los patrones y determinantes del ahorro para el retiro en Colombia a partir de la Gran Encuesta Integrada de Hogares de 2007. Los resultados muestran que el 63% de los ocupados declaran no ahorrar para su vejez. A partir de modelos de selección d...

  8. Application of random-point processes to the detection of radiation sources

    International Nuclear Information System (INIS)

    Woods, J.W.

    1978-01-01

    In this report the mathematical theory of random-point processes is reviewed and it is shown how use of the theory can obtain optimal solutions to the problem of detecting radiation sources. As noted, the theory also applies to image processing in low-light-level or low-count-rate situations. Paralleling Snyder's work, the theory is extended to the multichannel case of a continuous, two-dimensional (2-D), energy-time space. This extension essentially involves showing that the data are doubly stochastic Poisson (DSP) point processes in energy as well as time. Further, a new 2-D recursive formulation is presented for the radiation-detection problem with large computational savings over nonrecursive techniques when the number of channels is large (greater than or equal to 30). Finally, some adaptive strategies for on-line ''learning'' of unknown, time-varying signal and background-intensity parameters and statistics are present and discussed. These adaptive procedures apply when a complete statistical description is not available a priori

  9. Nuclear binding around the RP-process waiting points $^{68}$Se and $^{72}$Kr

    CERN Multimedia

    2002-01-01

    Encouraged by the success of mass determinations of nuclei close to the Z=N line performed at ISOLTRAP during the year 2000 and of the recent decay spectroscopy studies on neutron-deficient Kr isotopes (IS351 collaboration), we aim to measure masses and proton separation energies of the bottleneck nuclei defining the flow of the astrophysical rp-process beyond A$\\sim$70. In detail, the program includes mass measurements of the rp-process waiting point nuclei $^{68}$Se and $^{72}$Kr and determination of proton separation energies of the proton-unbound $^{69}$Br and $^{73}$Rb via $\\beta$-decays of $^{69}$Kr and $^{73}$Sr, respectively. The aim of the project is to complete the experimental database for astrophysical network calculations and for the liquid-drop type of mass models typically used in the modelling of the astrophysical rp process in the region. The first beamtime is scheduled for the August 2001 and the aim is to measure the absolute mass of the waiting-point nucleus $^{72}$Kr.

  10. Assessment of Peer Mediation Process from Conflicting Students’ Point of Views

    Directory of Open Access Journals (Sweden)

    Fulya TÜRK

    2016-12-01

    Full Text Available The purpose of this study was to analyze peer mediation process that was applied in a high school on conflicting students’ point of views. This research was carried out in a high school in Denizli. After ten sessions of training in peer mediation, peer mediators mediated peers’ real conflicts. In the research, 41 students (28 girls, 13 boys who got help at least once were interviewed as a party to the conflict. Through semistructured interviews with conflicting students, the mediation process has been evaluated through the point of views of students. Eight questions were asked about the conflicting parties. Verbal data obtained from interviews were analyzed using the content analysis. When conflicting students’ opinions and experiences about peer mediation were analyzed, it is seen that they were satisfied regarding the process, they have resolved their conflicts in a constructive and peaceful way, their friendship has been continuing as before. All of these results also indicate that peer mediation is an effective method of resolving student conflicts constructively

  11. Clusterless Decoding of Position From Multiunit Activity Using A Marked Point Process Filter

    Science.gov (United States)

    Deng, Xinyi; Liu, Daniel F.; Kay, Kenneth; Frank, Loren M.; Eden, Uri T.

    2016-01-01

    Point process filters have been applied successfully to decode neural signals and track neural dynamics. Traditionally, these methods assume that multiunit spiking activity has already been correctly spike-sorted. As a result, these methods are not appropriate for situations where sorting cannot be performed with high precision such as real-time decoding for brain-computer interfaces. As the unsupervised spike-sorting problem remains unsolved, we took an alternative approach that takes advantage of recent insights about clusterless decoding. Here we present a new point process decoding algorithm that does not require multiunit signals to be sorted into individual units. We use the theory of marked point processes to construct a function that characterizes the relationship between a covariate of interest (in this case, the location of a rat on a track) and features of the spike waveforms. In our example, we use tetrode recordings, and the marks represent a four-dimensional vector of the maximum amplitudes of the spike waveform on each of the four electrodes. In general, the marks may represent any features of the spike waveform. We then use Bayes’ rule to estimate spatial location from hippocampal neural activity. We validate our approach with a simulation study and with experimental data recorded in the hippocampus of a rat moving through a linear environment. Our decoding algorithm accurately reconstructs the rat’s position from unsorted multiunit spiking activity. We then compare the quality of our decoding algorithm to that of a traditional spike-sorting and decoding algorithm. Our analyses show that the proposed decoding algorithm performs equivalently or better than algorithms based on sorted single-unit activity. These results provide a path toward accurate real-time decoding of spiking patterns that could be used to carry out content-specific manipulations of population activity in hippocampus or elsewhere in the brain. PMID:25973549

  12. On the estimation of the spherical contact distribution Hs(y) for spatial point processes

    International Nuclear Information System (INIS)

    Doguwa, S.I.

    1990-08-01

    RIPLEY (1977, Journal of the Royal Statistical Society, B39 172-212) proposed an estimator for the spherical contact distribution H s (s), of a spatial point process observed in a bounded planar region. However, this estimator is not defined for some distances of interest, in this bounded region. A new estimator for H s (y), is proposed for use with regular grid of sampling locations. This new estimator is defined for all distances of interest. It also appears to have a smaller bias and a smaller mean squared error than the previously suggested alternative. (author). 11 refs, 4 figs, 1 tab

  13. Analysing the distribution of synaptic vesicles using a spatial point process model

    DEFF Research Database (Denmark)

    Khanmohammadi, Mahdieh; Waagepetersen, Rasmus; Nava, Nicoletta

    2014-01-01

    functionality by statistically modelling the distribution of the synaptic vesicles in two groups of rats: a control group subjected to sham stress and a stressed group subjected to a single acute foot-shock (FS)-stress episode. We hypothesize that the synaptic vesicles have different spatial distributions...... in the two groups. The spatial distributions are modelled using spatial point process models with an inhomogeneous conditional intensity and repulsive pairwise interactions. Our results verify the hypothesis that the two groups have different spatial distributions....

  14. Determinantes de la Calidad del Resultado

    Directory of Open Access Journals (Sweden)

    Carmen Pineda González

    2000-06-01

    Full Text Available El concepto de calidad del resultado hace referencia a la posibilidad de que el resultado contable sea percibido por los usuarios de la información contable por encima o por debajo de su cuantificación numérica, o, de otro modo, a la posibilidad de percibir como diferentes los resultados de varias compañías aun cuando en términos cuantitativos sean de igual valor; de forma que será de mayor calidad aquél resultado que en mayor medida contribuya a limitar o a reducir el riesgo inherente al proceso de toma de decisiones. Este concepto general, sin embargo, ha tenido diferentes concreciones que requieren un estudio detallado. En consecuencia, el objetivo de este trabajo es revisar las diferentes definiciones de calidad del resultado que recoge la bibliografía contable y analizar los factores que la determinan, es decir; las decisiones empresariales, las normas contables, la manipulación, la estabilidad, el contenido monetario y los componentes permanentes del resultado. The concept of earnings quality refers to the possibility that accounting results are valued either above or below their numerical quantification, or; put another way, to the possibility of detecting differences in the results of various companies even though in quantitative terms they are of equal value, such that the results of the highest quality will be those which limit, or reduce, to the greatest extent the risk inherent in the decision making process. This general concept, however; has had different forms that require detailed study. In consequence, this paper aims both to review the different definitions of earnings quality present in the accounting literature, and to analyse the factors that determine earnings quality including: corporate decisions, accounting standards and the manipulation, stability, monetary content and permanent components of earnings.

  15. The Impact of the Delivery of Prepared Power Point Presentations on the Learning Process

    Directory of Open Access Journals (Sweden)

    Auksė Marmienė

    2011-04-01

    Full Text Available This article describes the process of the preparation and delivery of Power Point presentations and how it can be used by teachers as a resource for classroom teaching. The advantages of this classroom activity covering some of the problems and providing a few suggestions for dealing with those difficulties are also outlined. The major objective of the present paper is to investigate the students ability to choose the material and the content of Power Point presentations on professional topics via the Internet as well as the ability to prepare and deliver the presentation in front of the audience. The factors which determine the choice of the presentation subject are also analysed in this paper. After the delivery students were requested to self- and peer-assess the difficulties they faced in preparation and performance of the presentations by writing the reports. Learners’ attitudes to the choice of the topic of Power Point presentations were surveyed by administering a self-assessment questionnaire.

  16. Process for quality assurance of welded joints for electrical resistance point welding

    International Nuclear Information System (INIS)

    Schaefer, R.; Singh, S.

    1977-01-01

    In order to guarantee the reproducibility of welded joints of even quality (above all in the metal working industry), it is proposed that before starting resistance point welding, a preheating current should be allowed to flow at the site of the weld. A given reduction of the total resistance at the site of the weld should effect the time when the preheating current is switched over to welding current. This value is always predetermined empirically. Further possibilities of controlling the welding process are described, where the measurement of thermal expansion of the parts is used. A standard welding time is given. The rated course of electrode movement during the process can be predicted and a running comparison of nominal and actual values can be carried out. (RW) [de

  17. Implementation of 5S tools as a starting point in business process reengineering

    Directory of Open Access Journals (Sweden)

    Vorkapić Miloš 0000-0002-3463-8665

    2017-01-01

    Full Text Available The paper deals with the analysis of elements which represent a starting point in implementation of a business process reengineering. We have used Lean tools through the analysis of 5S model in our research. On the example of finalization of the finished transmitter in IHMT-CMT production, 5S tools were implemented with a focus on Quality elements although the theory shows that BPR and TQM are two opposite activities in an enterprise. We wanted to distinguish the significance of employees’ self-discipline which helps the process of product finalization to develop in time and without waste and losses. In addition, the employees keep their work place clean, tidy and functional.

  18. Comparison of plastic strains on AA5052 by single point incremental forming process using digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Mugendiran, V.; Gnanavelbabu, A. [Anna University, Chennai, Tamilnadu (India)

    2017-06-15

    In this study, a surface based strain measurement was used to determine the formability of the sheet metal. A strain measurement may employ manual calculation of plastic strains based on the reference circle and the deformed circle. The manual calculation method has a greater margin of error in the practical applications. In this paper, an attempt has been made to compare the formability by implementing three different theoretical approaches: Namely conventional method, least square method and digital based strain measurements. As the sheet metal was formed by a single point incremental process the etched circles get deformed into elliptical shapes approximately, image acquisition has been done before and after forming. The plastic strains of the deformed circle grids are calculated based on the non- deformed reference. The coordinates of the deformed circles are measured by various image processing steps. Finally the strains obtained from the deformed circle are used to plot the forming limit diagram. To evaluate the accuracy of the system, the conventional, least square and digital based method of prediction of the forming limit diagram was compared. Conventional method and least square method have marginal error when compared with digital based processing method. Measurement of strain based on image processing agrees well and can be used to improve the accuracy and to reduce the measurement error in prediction of forming limit diagram.

  19. Comparison of plastic strains on AA5052 by single point incremental forming process using digital image processing

    International Nuclear Information System (INIS)

    Mugendiran, V.; Gnanavelbabu, A.

    2017-01-01

    In this study, a surface based strain measurement was used to determine the formability of the sheet metal. A strain measurement may employ manual calculation of plastic strains based on the reference circle and the deformed circle. The manual calculation method has a greater margin of error in the practical applications. In this paper, an attempt has been made to compare the formability by implementing three different theoretical approaches: Namely conventional method, least square method and digital based strain measurements. As the sheet metal was formed by a single point incremental process the etched circles get deformed into elliptical shapes approximately, image acquisition has been done before and after forming. The plastic strains of the deformed circle grids are calculated based on the non- deformed reference. The coordinates of the deformed circles are measured by various image processing steps. Finally the strains obtained from the deformed circle are used to plot the forming limit diagram. To evaluate the accuracy of the system, the conventional, least square and digital based method of prediction of the forming limit diagram was compared. Conventional method and least square method have marginal error when compared with digital based processing method. Measurement of strain based on image processing agrees well and can be used to improve the accuracy and to reduce the measurement error in prediction of forming limit diagram.

  20. Neutron capture at the s-process branching points $^{171}$Tm and $^{204}$Tl

    CERN Multimedia

    Branching points in the s-process are very special isotopes for which there is a competition between the neutron capture and the subsequent b-decay chain producing the heavy elements beyond Fe. Typically, the knowledge on the associated capture cross sections is very poor due to the difficulty in obtaining enough material of these radioactive isotopes and to measure the cross section of a sample with an intrinsic activity; indeed only 2 out o the 21 ${s}$-process branching points have ever been measured by using the time-of-flight method. In this experiment we aim at measuring for the first time the capture cross sections of $^{171}$Tm and $^{204}$Tl, both of crucial importance for understanding the nucleosynthesis of heavy elements in AGB stars. The combination of both (n,$\\gamma$) measurements on $^{171}$Tm and $^{204}$Tl will allow one to accurately constrain neutron density and the strength of the 13C(α,n) source in low mass AGB stars. Additionally, the cross section of $^{204}$Tl is also of cosmo-chrono...

  1. Detection of bursts in extracellular spike trains using hidden semi-Markov point process models.

    Science.gov (United States)

    Tokdar, Surya; Xi, Peiyi; Kelly, Ryan C; Kass, Robert E

    2010-08-01

    Neurons in vitro and in vivo have epochs of bursting or "up state" activity during which firing rates are dramatically elevated. Various methods of detecting bursts in extracellular spike trains have appeared in the literature, the most widely used apparently being Poisson Surprise (PS). A natural description of the phenomenon assumes (1) there are two hidden states, which we label "burst" and "non-burst," (2) the neuron evolves stochastically, switching at random between these two states, and (3) within each state the spike train follows a time-homogeneous point process. If in (2) the transitions from non-burst to burst and burst to non-burst states are memoryless, this becomes a hidden Markov model (HMM). For HMMs, the state transitions follow exponential distributions, and are highly irregular. Because observed bursting may in some cases be fairly regular-exhibiting inter-burst intervals with small variation-we relaxed this assumption. When more general probability distributions are used to describe the state transitions the two-state point process model becomes a hidden semi-Markov model (HSMM). We developed an efficient Bayesian computational scheme to fit HSMMs to spike train data. Numerical simulations indicate the method can perform well, sometimes yielding very different results than those based on PS.

  2. Mixed-Poisson Point Process with Partially-Observed Covariates: Ecological Momentary Assessment of Smoking.

    Science.gov (United States)

    Neustifter, Benjamin; Rathbun, Stephen L; Shiffman, Saul

    2012-01-01

    Ecological Momentary Assessment is an emerging method of data collection in behavioral research that may be used to capture the times of repeated behavioral events on electronic devices, and information on subjects' psychological states through the electronic administration of questionnaires at times selected from a probability-based design as well as the event times. A method for fitting a mixed Poisson point process model is proposed for the impact of partially-observed, time-varying covariates on the timing of repeated behavioral events. A random frailty is included in the point-process intensity to describe variation among subjects in baseline rates of event occurrence. Covariate coefficients are estimated using estimating equations constructed by replacing the integrated intensity in the Poisson score equations with a design-unbiased estimator. An estimator is also proposed for the variance of the random frailties. Our estimators are robust in the sense that no model assumptions are made regarding the distribution of the time-varying covariates or the distribution of the random effects. However, subject effects are estimated under gamma frailties using an approximate hierarchical likelihood. The proposed approach is illustrated using smoking data.

  3. Students’ Algebraic Thinking Process in Context of Point and Line Properties

    Science.gov (United States)

    Nurrahmi, H.; Suryadi, D.; Fatimah, S.

    2017-09-01

    Learning of schools algebra is limited to symbols and operating procedures, so students are able to work on problems that only require the ability to operate symbols but unable to generalize a pattern as one of part of algebraic thinking. The purpose of this study is to create a didactic design that facilitates students to do algebraic thinking process through the generalization of patterns, especially in the context of the property of point and line. This study used qualitative method and includes Didactical Design Research (DDR). The result is students are able to make factual, contextual, and symbolic generalization. This happen because the generalization arises based on facts on local terms, then the generalization produced an algebraic formula that was described in the context and perspective of each student. After that, the formula uses the algebraic letter symbol from the symbol t hat uses the students’ language. It can be concluded that the design has facilitated students to do algebraic thinking process through the generalization of patterns, especially in the context of property of the point and line. The impact of this study is this design can use as one of material teaching alternative in learning of school algebra.

  4. Topobathymetric LiDAR point cloud processing and landform classification in a tidal environment

    Science.gov (United States)

    Skovgaard Andersen, Mikkel; Al-Hamdani, Zyad; Steinbacher, Frank; Rolighed Larsen, Laurids; Brandbyge Ernstsen, Verner

    2017-04-01

    Historically it has been difficult to create high resolution Digital Elevation Models (DEMs) in land-water transition zones due to shallow water depth and often challenging environmental conditions. This gap of information has been reflected as a "white ribbon" with no data in the land-water transition zone. In recent years, the technology of airborne topobathymetric Light Detection and Ranging (LiDAR) has proven capable of filling out the gap by simultaneously capturing topographic and bathymetric elevation information, using only a single green laser. We collected green LiDAR point cloud data in the Knudedyb tidal inlet system in the Danish Wadden Sea in spring 2014. Creating a DEM from a point cloud requires the general processing steps of data filtering, water surface detection and refraction correction. However, there is no transparent and reproducible method for processing green LiDAR data into a DEM, specifically regarding the procedure of water surface detection and modelling. We developed a step-by-step procedure for creating a DEM from raw green LiDAR point cloud data, including a procedure for making a Digital Water Surface Model (DWSM) (see Andersen et al., 2017). Two different classification analyses were applied to the high resolution DEM: A geomorphometric and a morphological classification, respectively. The classification methods were originally developed for a small test area; but in this work, we have used the classification methods to classify the complete Knudedyb tidal inlet system. References Andersen MS, Gergely Á, Al-Hamdani Z, Steinbacher F, Larsen LR, Ernstsen VB (2017). Processing and performance of topobathymetric lidar data for geomorphometric and morphological classification in a high-energy tidal environment. Hydrol. Earth Syst. Sci., 21: 43-63, doi:10.5194/hess-21-43-2017. Acknowledgements This work was funded by the Danish Council for Independent Research | Natural Sciences through the project "Process-based understanding and

  5. Point process modeling and estimation: Advances in the analysis of dynamic neural spiking data

    Science.gov (United States)

    Deng, Xinyi

    2016-08-01

    A common interest of scientists in many fields is to understand the relationship between the dynamics of a physical system and the occurrences of discrete events within such physical system. Seismologists study the connection between mechanical vibrations of the Earth and the occurrences of earthquakes so that future earthquakes can be better predicted. Astrophysicists study the association between the oscillating energy of celestial regions and the emission of photons to learn the Universe's various objects and their interactions. Neuroscientists study the link between behavior and the millisecond-timescale spike patterns of neurons to understand higher brain functions. Such relationships can often be formulated within the framework of state-space models with point process observations. The basic idea is that the dynamics of the physical systems are driven by the dynamics of some stochastic state variables and the discrete events we observe in an interval are noisy observations with distributions determined by the state variables. This thesis proposes several new methodological developments that advance the framework of state-space models with point process observations at the intersection of statistics and neuroscience. In particular, we develop new methods 1) to characterize the rhythmic spiking activity using history-dependent structure, 2) to model population spike activity using marked point process models, 3) to allow for real-time decision making, and 4) to take into account the need for dimensionality reduction for high-dimensional state and observation processes. We applied these methods to a novel problem of tracking rhythmic dynamics in the spiking of neurons in the subthalamic nucleus of Parkinson's patients with the goal of optimizing placement of deep brain stimulation electrodes. We developed a decoding algorithm that can make decision in real-time (for example, to stimulate the neurons or not) based on various sources of information present in

  6. Nuclear structure and weak rates of heavy waiting point nuclei under rp-process conditions

    Science.gov (United States)

    Nabi, Jameel-Un; Böyükata, Mahmut

    2017-01-01

    The structure and the weak interaction mediated rates of the heavy waiting point (WP) nuclei 80Zr, 84Mo, 88Ru, 92Pd and 96Cd along N = Z line were studied within the interacting boson model-1 (IBM-1) and the proton-neutron quasi-particle random phase approximation (pn-QRPA). The energy levels of the N = Z WP nuclei were calculated by fitting the essential parameters of IBM-1 Hamiltonian and their geometric shapes were predicted by plotting potential energy surfaces (PESs). Half-lives, continuum electron capture rates, positron decay rates, electron capture cross sections of WP nuclei, energy rates of β-delayed protons and their emission probabilities were later calculated using the pn-QRPA. The calculated Gamow-Teller strength distributions were compared with previous calculation. We present positron decay and continuum electron capture rates on these WP nuclei under rp-process conditions using the same model. For the rp-process conditions, the calculated total weak rates are twice the Skyrme HF+BCS+QRPA rates for 80Zr. For remaining nuclei the two calculations compare well. The electron capture rates are significant and compete well with the corresponding positron decay rates under rp-process conditions. The finding of the present study supports that electron capture rates form an integral part of the weak rates under rp-process conditions and has an important role for the nuclear model calculations.

  7. Radial Basis Functional Model of Multi-Point Dieless Forming Process for Springback Reduction and Compensation

    Directory of Open Access Journals (Sweden)

    Misganaw Abebe

    2017-11-01

    Full Text Available Springback in multi-point dieless forming (MDF is a common problem because of the small deformation and blank holder free boundary condition. Numerical simulations are widely used in sheet metal forming to predict the springback. However, the computational time in using the numerical tools is time costly to find the optimal process parameters value. This study proposes radial basis function (RBF to replace the numerical simulation model by using statistical analyses that are based on a design of experiment (DOE. Punch holding time, blank thickness, and curvature radius are chosen as effective process parameters for determining the springback. The Latin hypercube DOE method facilitates statistical analyses and the extraction of a prediction model in the experimental process parameter domain. Finite element (FE simulation model is conducted in the ABAQUS commercial software to generate the springback responses of the training and testing samples. The genetic algorithm is applied to find the optimal value for reducing and compensating the induced springback for the different blank thicknesses using the developed RBF prediction model. Finally, the RBF numerical result is verified by comparing with the FE simulation result of the optimal process parameters and both results show that the springback is almost negligible from the target shape.

  8. On the stability and dynamics of stochastic spiking neuron models: Nonlinear Hawkes process and point process GLMs.

    Science.gov (United States)

    Gerhard, Felipe; Deger, Moritz; Truccolo, Wilson

    2017-02-01

    Point process generalized linear models (PP-GLMs) provide an important statistical framework for modeling spiking activity in single-neurons and neuronal networks. Stochastic stability is essential when sampling from these models, as done in computational neuroscience to analyze statistical properties of neuronal dynamics and in neuro-engineering to implement closed-loop applications. Here we show, however, that despite passing common goodness-of-fit tests, PP-GLMs estimated from data are often unstable, leading to divergent firing rates. The inclusion of absolute refractory periods is not a satisfactory solution since the activity then typically settles into unphysiological rates. To address these issues, we derive a framework for determining the existence and stability of fixed points of the expected conditional intensity function (CIF) for general PP-GLMs. Specifically, in nonlinear Hawkes PP-GLMs, the CIF is expressed as a function of the previous spike history and exogenous inputs. We use a mean-field quasi-renewal (QR) approximation that decomposes spike history effects into the contribution of the last spike and an average of the CIF over all spike histories prior to the last spike. Fixed points for stationary rates are derived as self-consistent solutions of integral equations. Bifurcation analysis and the number of fixed points predict that the original models can show stable, divergent, and metastable (fragile) dynamics. For fragile models, fluctuations of the single-neuron dynamics predict expected divergence times after which rates approach unphysiologically high values. This metric can be used to estimate the probability of rates to remain physiological for given time periods, e.g., for simulation purposes. We demonstrate the use of the stability framework using simulated single-neuron examples and neurophysiological recordings. Finally, we show how to adapt PP-GLM estimation procedures to guarantee model stability. Overall, our results provide a

  9. Predicting seizures in untreated temporal lobe epilepsy using point-process nonlinear models of heartbeat dynamics.

    Science.gov (United States)

    Valenza, G; Romigi, A; Citi, L; Placidi, F; Izzi, F; Albanese, M; Scilingo, E P; Marciani, M G; Duggento, A; Guerrisi, M; Toschi, N; Barbieri, R

    2016-08-01

    Symptoms of temporal lobe epilepsy (TLE) are frequently associated with autonomic dysregulation, whose underlying biological processes are thought to strongly contribute to sudden unexpected death in epilepsy (SUDEP). While abnormal cardiovascular patterns commonly occur during ictal events, putative patterns of autonomic cardiac effects during pre-ictal (PRE) periods (i.e. periods preceding seizures) are still unknown. In this study, we investigated TLE-related heart rate variability (HRV) through instantaneous, nonlinear estimates of cardiovascular oscillations during inter-ictal (INT) and PRE periods. ECG recordings from 12 patients with TLE were processed to extract standard HRV indices, as well as indices of instantaneous HRV complexity (dominant Lyapunov exponent and entropy) and higher-order statistics (bispectra) obtained through definition of inhomogeneous point-process nonlinear models, employing Volterra-Laguerre expansions of linear, quadratic, and cubic kernels. Experimental results demonstrate that the best INT vs. PRE classification performance (balanced accuracy: 73.91%) was achieved only when retaining the time-varying, nonlinear, and non-stationary structure of heartbeat dynamical features. The proposed approach opens novel important avenues in predicting ictal events using information gathered from cardiovascular signals exclusively.

  10. A customizable stochastic state point process filter (SSPPF) for neural spiking activity.

    Science.gov (United States)

    Xin, Yao; Li, Will X Y; Min, Biao; Han, Yan; Cheung, Ray C C

    2013-01-01

    Stochastic State Point Process Filter (SSPPF) is effective for adaptive signal processing. In particular, it has been successfully applied to neural signal coding/decoding in recent years. Recent work has proven its efficiency in non-parametric coefficients tracking in modeling of mammal nervous system. However, existing SSPPF has only been realized in commercial software platforms which limit their computational capability. In this paper, the first hardware architecture of SSPPF has been designed and successfully implemented on field-programmable gate array (FPGA), proving a more efficient means for coefficient tracking in a well-established generalized Laguerre-Volterra model for mammalian hippocampal spiking activity research. By exploring the intrinsic parallelism of the FPGA, the proposed architecture is able to process matrices or vectors with random size, and is efficiently scalable. Experimental result shows its superior performance comparing to the software implementation, while maintaining the numerical precision. This architecture can also be potentially utilized in the future hippocampal cognitive neural prosthesis design.

  11. Continuous quality improvement process pin-points delays, speeds STEMI patients to life-saving treatment.

    Science.gov (United States)

    2011-11-01

    Using a multidisciplinary team approach, the University of California, San Diego, Health System has been able to significantly reduce average door-to-balloon angioplasty times for patients with the most severe form of heart attacks, beating national recommendations by more than a third. The multidisciplinary team meets monthly to review all cases involving patients with ST-segment-elevation myocardial infarctions (STEMI) to see where process improvements can be made. Using this continuous quality improvement (CQI) process, the health system has reduced average door-to-balloon times from 120 minutes to less than 60 minutes, and administrators are now aiming for further progress. Among the improvements instituted by the multidisciplinary team are the implementation of a "greeter" with enough clinical expertise to quickly pick up on potential STEMI heart attacks as soon as patients walk into the ED, and the purchase of an electrocardiogram (EKG) machine so that evaluations can be done in the triage area. ED staff have prepared "STEMI" packets, including items such as special IV tubing and disposable leads, so that patients headed for the catheterization laboratory are prepared to undergo the procedure soon after arrival. All the clocks and devices used in the ED are synchronized so that analysts can later review how long it took to complete each step of the care process. Points of delay can then be targeted for improvement.

  12. A Unified Point Process Probabilistic Framework to Assess Heartbeat Dynamics and Autonomic Cardiovascular Control

    Directory of Open Access Journals (Sweden)

    Zhe eChen

    2012-02-01

    Full Text Available In recent years, time-varying inhomogeneous point process models have been introduced for assessment of instantaneous heartbeat dynamics as well as specific cardiovascular control mechanisms and hemodynamics. Assessment of the model's statistics is established through the Wiener-Volterra theory and a multivariate autoregressive (AR structure. A variety of instantaneous cardiovascular metrics, such as heart rate (HR, heart rate variability (HRV, respiratory sinus arrhythmia (RSA, and baroreceptor-cardiac reflex (baroreflex sensitivity (BRS, are derived within a parametric framework and instantaneously updated with adaptive and local maximum likelihood estimation algorithms. Inclusion of second order nonlinearities, with subsequent bispectral quantification in the frequency domain, further allows for definition of instantaneous metrics of nonlinearity. We here organize a comprehensive review of the devised methods as applied to experimental recordings from healthy subjects during propofol anesthesia. Collective results reveal interesting dynamic trends across the different pharmacological interventions operated within each anesthesia session, confirming the ability of the algorithm to track important changes in cardiorespiratory elicited interactions, and pointing at our mathematical approach as a promising monitoring tool for an accurate, noninvasive assessment in clinical practice.

  13. Catalysts macroporosity and their efficiency in sulphur sub-dew point Claus tail gas treating processes

    Energy Technology Data Exchange (ETDEWEB)

    Tsybulevski, A.M.; Pearson, M. [Alcoa Industrial Chemicals, 16010 Barker`s Point Lane, Houston, TX (United States); Morgun, L.V.; Filatova, O.E. [All-Russian Research Institute of Natural Gases and Gas Technologies VNIIGAZ, Moscow (Russian Federation); Sharp, M. [Porocel Corporation, Westheimer, Houston, TX (United States)

    1996-10-08

    The efficiency of 4 samples of alumina catalyst has been studied experimentally in the course of the Claus `tail gas` treating processes at the sulphur sub-dew point (TGTP). The samples were characterized by the same chemical and crystallographic composition, the same volume of micropores, the same surface area and the same catalytic activity but differed appreciably in the volume of macropores. An increase in the effective operation time of the catalysts before breakthrough of unrecoverable sulphur containing compounds, with the increasing macropore volume has been established. A theoretical model of the TGTP has been considered and it has been shown that the increase in the sulphur capacity of the catalysts with a larger volume of macropores is due to an increase in the catalysts efficiency factor and a slower decrease in their diffusive permeability during filling of micropores by sulphur

  14. Quantification of annual wildfire risk; A spatio-temporal point process approach.

    Directory of Open Access Journals (Sweden)

    Paula Pereira

    2013-10-01

    Full Text Available Policy responses for local and global firemanagement depend heavily on the proper understanding of the fire extent as well as its spatio-temporal variation across any given study area. Annual fire risk maps are important tools for such policy responses, supporting strategic decisions such as location-allocation of equipment and human resources. Here, we define risk of fire in the narrow sense as the probability of its occurrence without addressing the loss component. In this paper, we study the spatio-temporal point patterns of wildfires and model them by a log Gaussian Cox processes. Themean of predictive distribution of randomintensity function is used in the narrow sense, as the annual fire risk map for next year.

  15. The (n, $\\gamma$) reaction in the s-process branching point $^{59}$Ni

    CERN Multimedia

    We propose to measure the $^{59}$Ni(n,$\\gamma$)$^{56}$Fe cross section at the neutron time of flight (n TOF) facility with a dedicated chemical vapor deposition (CVD) diamond detector. The (n, ) reaction in the radioactive $^{59}$Ni is of relevance in nuclear astrophysics as it can be seen as a rst branching point in the astrophysical s-process. Its relevance in nuclear technology is especially related to material embrittlement in stainless steel. There is a strong discrepancy between available experimental data and the evaluated nuclear data les for this isotope. The aim of the measurement is to clarify this disagreement. The clear energy separation of the reaction products of neutron induced reactions in $^{59}$Ni makes it a very suitable candidate for a rst cross section measurement with the CVD diamond detector, which should serve in the future for similar measurements at n_TOF.

  16. Quantifying structural uncertainty on fault networks using a marked point process within a Bayesian framework

    Science.gov (United States)

    Aydin, Orhun; Caers, Jef Karel

    2017-08-01

    Faults are one of the building-blocks for subsurface modeling studies. Incomplete observations of subsurface fault networks lead to uncertainty pertaining to location, geometry and existence of faults. In practice, gaps in incomplete fault network observations are filled based on tectonic knowledge and interpreter's intuition pertaining to fault relationships. Modeling fault network uncertainty with realistic models that represent tectonic knowledge is still a challenge. Although methods that address specific sources of fault network uncertainty and complexities of fault modeling exists, a unifying framework is still lacking. In this paper, we propose a rigorous approach to quantify fault network uncertainty. Fault pattern and intensity information are expressed by means of a marked point process, marked Strauss point process. Fault network information is constrained to fault surface observations (complete or partial) within a Bayesian framework. A structural prior model is defined to quantitatively express fault patterns, geometries and relationships within the Bayesian framework. Structural relationships between faults, in particular fault abutting relations, are represented with a level-set based approach. A Markov Chain Monte Carlo sampler is used to sample posterior fault network realizations that reflect tectonic knowledge and honor fault observations. We apply the methodology to a field study from Nankai Trough & Kumano Basin. The target for uncertainty quantification is a deep site with attenuated seismic data with only partially visible faults and many faults missing from the survey or interpretation. A structural prior model is built from shallow analog sites that are believed to have undergone similar tectonics compared to the site of study. Fault network uncertainty for the field is quantified with fault network realizations that are conditioned to structural rules, tectonic information and partially observed fault surfaces. We show the proposed

  17. Structured spatio-temporal shot-noise Cox point process models, with a view to modelling forest fires

    DEFF Research Database (Denmark)

    Møller, Jesper; Diaz-Avalos, Carlos

    Spatio-temporal Cox point process models with a multiplicative structure for the driving random intensity, incorporating covariate information into temporal and spatial components, and with a residual term modelled by a shot-noise process, are considered. Such models are flexible and tractable fo...... dataset consisting of 2796 days and 5834 spatial locations of fires. The model is compared with a spatio-temporal log-Gaussian Cox point process model, and likelihood-based methods are discussed to some extent....

  18. A Multi-Point Method Considering the Maximum Power Point Tracking Dynamic Process for Aerodynamic Optimization of Variable-Speed Wind Turbine Blades

    Directory of Open Access Journals (Sweden)

    Zhiqiang Yang

    2016-05-01

    Full Text Available Due to the dynamic process of maximum power point tracking (MPPT caused by turbulence and large rotor inertia, variable-speed wind turbines (VSWTs cannot maintain the optimal tip speed ratio (TSR from cut-in wind speed up to the rated speed. Therefore, in order to increase the total captured wind energy, the existing aerodynamic design for VSWT blades, which only focuses on performance improvement at a single TSR, needs to be improved to a multi-point design. In this paper, based on a closed-loop system of VSWTs, including turbulent wind, rotor, drive train and MPPT controller, the distribution of operational TSR and its description based on inflow wind energy are investigated. Moreover, a multi-point method considering the MPPT dynamic process for the aerodynamic optimization of VSWT blades is proposed. In the proposed method, the distribution of operational TSR is obtained through a dynamic simulation of the closed-loop system under a specific turbulent wind, and accordingly the multiple design TSRs and the corresponding weighting coefficients in the objective function are determined. Finally, using the blade of a National Renewable Energy Laboratory (NREL 1.5 MW wind turbine as the baseline, the proposed method is compared with the conventional single-point optimization method using the commercial software Bladed. Simulation results verify the effectiveness of the proposed method.

  19. Determinantes de la cuenta corriente en Colombia: un enfoque intertempora

    Directory of Open Access Journals (Sweden)

    Elkin Castaño,

    1999-07-01

    Full Text Available Este trabajo pretende examinar los determinantes de la cuenta corriente en Colombia entre 1950 y 1997 a partir del enfoque intertemporal. Este plantea, en su forma más simple, que las desviaciones transitorias del ingreso, del consumo privado y del consumo público, afectan positivamente, en el primer caso, y negativamente, en el segundo y tercero a la cuenta corriente. Esto es, los agentes económicos financian las caídas transitorias del producto y los aumentos del consumo, con respecto a sus niveles permanentes, mediante mayores ahorros externos, generando un déficit en cuenta corriente. La comprobación econométrica arroja evidencia favorable al enfoque intertemporal utilizado. Los movimientos de la cuenta corriente parecen estar más estrechamente asociados con las variaciones en el ahorro que en la inversión.

  20. Determinantes del ingreso y del gasto corriente de los hogares

    Directory of Open Access Journals (Sweden)

    Muñoz C., Manuel

    2004-06-01

    Full Text Available Este ensayo de investigación empírica analiza los determinantes del ingreso y del gasto en los hogares colombianos. Utilizando un modelo del ciclo de vida con datos de la encuesta de hogares de 1994 y 1995, muestra que el comportamiento del ingreso está afectado principalmente por las características demográficas del hogar y los rasgos socio ocupacionales de sus miembros. El comportamiento del gasto está determinado ante todo por el ingreso y, en menor medida, por las características sociales del hogar y el gasto de otros hogares con características similares. También examina la influencia de la incertidumbre acerca de los ingresos en el gasto de los hogares para comprobar si estos actúan con motivos de precaución.

  1. Exportaciones del Valle del Cauca. Determinantes, comportamiento y prospectiva

    Directory of Open Access Journals (Sweden)

    Dubán F. Peña Benítez

    2007-01-01

    Full Text Available Este trabajo centra su análisis en los determinantes de las exportaciones del Valle del Cauca en el periodo 1970 - 2004 y, en una predicción de corto y mediano plazo a través de un VAR y una función generalizada de impulso respuesta. Los hallazgos mostraron significancía de variables como el ingreso mundial (IM, el precio de los bienes exportables (TCR, los acuerdos comerciales (Aptdea y la dinámica de la oferta exportable (XV-1. La predicción para las exportaciones de la región estableció que la TCR tiene efectos positivos en el corto plazo, el ingreso mundial (IM impacta de forma positiva más en el largo que en el corto plazo y la variable acuerdos comerciales muestra importancia sólo de corto mas no de largo plazo.

  2. Insights into mortality patterns and causes of death through a process point of view model.

    Science.gov (United States)

    Anderson, James J; Li, Ting; Sharrow, David J

    2017-02-01

    Process point of view (POV) models of mortality, such as the Strehler-Mildvan and stochastic vitality models, represent death in terms of the loss of survival capacity through challenges and dissipation. Drawing on hallmarks of aging, we link these concepts to candidate biological mechanisms through a framework that defines death as challenges to vitality where distal factors defined the age-evolution of vitality and proximal factors define the probability distribution of challenges. To illustrate the process POV, we hypothesize that the immune system is a mortality nexus, characterized by two vitality streams: increasing vitality representing immune system development and immunosenescence representing vitality dissipation. Proximal challenges define three mortality partitions: juvenile and adult extrinsic mortalities and intrinsic adult mortality. Model parameters, generated from Swedish mortality data (1751-2010), exhibit biologically meaningful correspondences to economic, health and cause-of-death patterns. The model characterizes the twentieth century epidemiological transition mainly as a reduction in extrinsic mortality resulting from a shift from high magnitude disease challenges on individuals at all vitality levels to low magnitude stress challenges on low vitality individuals. Of secondary importance, intrinsic mortality was described by a gradual reduction in the rate of loss of vitality presumably resulting from reduction in the rate of immunosenescence. Extensions and limitations of a distal/proximal framework for characterizing more explicit causes of death, e.g. the young adult mortality hump or cancer in old age are discussed.

  3. Interevent Time Distribution of Renewal Point Process, Case Study: Extreme Rainfall in South Sulawesi

    Science.gov (United States)

    Sunusi, Nurtiti

    2018-03-01

    The study of time distribution of occurrences of extreme rain phenomena plays a very important role in the analysis and weather forecast in an area. The timing of extreme rainfall is difficult to predict because its occurrence is random. This paper aims to determine the inter event time distribution of extreme rain events and minimum waiting time until the occurrence of next extreme event through a point process approach. The phenomenon of extreme rain events over a given period of time is following a renewal process in which the time for events is a random variable τ. The distribution of random variable τ is assumed to be a Pareto, Log Normal, and Gamma. To estimate model parameters, a moment method is used. Consider Rt as the time of the last extreme rain event at one location is the time difference since the last extreme rainfall event. if there are no extreme rain events up to t 0, there will be an opportunity for extreme rainfall events at (t 0, t 0 + δt 0). Furthermore from the three models reviewed, the minimum waiting time until the next extreme rainfall will be determined. The result shows that Log Nrmal model is better than Pareto and Gamma model for predicting the next extreme rainfall in South Sulawesi while the Pareto model can not be used.

  4. The neutron capture cross section of the ${s}$-process branch point isotope $^{63}$Ni

    CERN Multimedia

    Neutron capture nucleosynthesis in massive stars plays an important role in Galactic chemical evolution as well as for the analysis of abundance patterns in very old metal-poor halo stars. The so-called weak ${s}$-process component, which is responsible for most of the ${s}$ abundances between Fe and Sr, turned out to be very sensitive to the stellar neutron capture cross sections in this mass region and, in particular, of isotopes near the seed distribution around Fe. In this context, the unstable isotope $^{63}$Ni is of particular interest because it represents the first branching point in the reaction path of the ${s}$-process. We propose to measure this cross section at n_TOF from thermal energies up to 500 keV, covering the entire range of astrophysical interest. These data are needed to replace uncertain theoretical predicitons by first experimental information to understand the consequences of the $^{63}$Ni branching for the abundance pattern of the subsequent isotopes, especially for $^{63}$Cu and $^{...

  5. Birth-death models and coalescent point processes: the shape and probability of reconstructed phylogenies.

    Science.gov (United States)

    Lambert, Amaury; Stadler, Tanja

    2013-12-01

    Forward-in-time models of diversification (i.e., speciation and extinction) produce phylogenetic trees that grow "vertically" as time goes by. Pruning the extinct lineages out of such trees leads to natural models for reconstructed trees (i.e., phylogenies of extant species). Alternatively, reconstructed trees can be modelled by coalescent point processes (CPPs), where trees grow "horizontally" by the sequential addition of vertical edges. Each new edge starts at some random speciation time and ends at the present time; speciation times are drawn from the same distribution independently. CPPs lead to extremely fast computation of tree likelihoods and simulation of reconstructed trees. Their topology always follows the uniform distribution on ranked tree shapes (URT). We characterize which forward-in-time models lead to URT reconstructed trees and among these, which lead to CPP reconstructed trees. We show that for any "asymmetric" diversification model in which speciation rates only depend on time and extinction rates only depend on time and on a non-heritable trait (e.g., age), the reconstructed tree is CPP, even if extant species are incompletely sampled. If rates additionally depend on the number of species, the reconstructed tree is (only) URT (but not CPP). We characterize the common distribution of speciation times in the CPP description, and discuss incomplete species sampling as well as three special model cases in detail: (1) the extinction rate does not depend on a trait; (2) rates do not depend on time; (3) mass extinctions may happen additionally at certain points in the past. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Approaching the r-process "waiting point" nuclei below $^{132}$Sn: quadrupole collectivity in $^{128}$Cd

    CERN Multimedia

    Reiter, P; Blazhev, A A; Nardelli, S; Voulot, D; Habs, D; Schwerdtfeger, W; Iwanicki, J S

    We propose to investigate the nucleus $^{128}$Cd neighbouring the r-process "waiting point" $^{130}$Cd. A possible explanation for the peak in the solar r-abundances at A $\\approx$ 130 is a quenching of the N = 82 shell closure for spherical nuclei below $^{132}$Sn. This explanation seems to be in agreement with recent $\\beta$-decay measurements performed at ISOLDE. In contrast to this picture, a beyond-mean-field approach would explain the anomaly in the excitation energy observed for $^{128}$Cd rather with a quite large quadrupole collectivity. Therefore, we propose to measure the reduced transition strengths B(E2) between ground state and first excited 2$^{+}$-state in $^{128}$Cd applying $\\gamma$-spectroscopy with MINIBALL after "safe" Coulomb excitation of a post-accelerated beam obtained from REX-ISOLDE. Such a measurement came into reach only because of the source developments made in 2006 for experiment IS411, in particular the use of a heated quartz transfer line. The result from the proposed measure...

  7. Process-based coastal erosion modeling for Drew Point (North Slope, Alaska)

    Science.gov (United States)

    Ravens, Thomas M.; Jones, Benjamin M.; Zhang, Jinlin; Arp, Christopher D.; Schmutz, Joel A.

    2012-01-01

    A predictive, coastal erosion/shoreline change model has been developed for a small coastal segment near Drew Point, Beaufort Sea, Alaska. This coastal setting has experienced a dramatic increase in erosion since the early 2000’s. The bluffs at this site are 3-4 m tall and consist of ice-wedge bounded blocks of fine-grained sediments cemented by ice-rich permafrost and capped with a thin organic layer. The bluffs are typically fronted by a narrow (∼ 5  m wide) beach or none at all. During a storm surge, the sea contacts the base of the bluff and a niche is formed through thermal and mechanical erosion. The niche grows both vertically and laterally and eventually undermines the bluff, leading to block failure or collapse. The fallen block is then eroded both thermally and mechanically by waves and currents, which must occur before a new niche forming episode may begin. The erosion model explicitly accounts for and integrates a number of these processes including: (1) storm surge generation resulting from wind and atmospheric forcing, (2) erosional niche growth resulting from wave-induced turbulent heat transfer and sediment transport (using the Kobayashi niche erosion model), and (3) thermal and mechanical erosion of the fallen block. The model was calibrated with historic shoreline change data for one time period (1979-2002), and validated with a later time period (2002-2007).

  8. Generating Impact Maps from Automatically Detected Bomb Craters in Aerial Wartime Images Using Marked Point Processes

    Science.gov (United States)

    Kruse, Christian; Rottensteiner, Franz; Hoberg, Thorsten; Ziems, Marcel; Rebke, Julia; Heipke, Christian

    2018-04-01

    The aftermath of wartime attacks is often felt long after the war ended, as numerous unexploded bombs may still exist in the ground. Typically, such areas are documented in so-called impact maps which are based on the detection of bomb craters. This paper proposes a method for the automatic detection of bomb craters in aerial wartime images that were taken during the Second World War. The object model for the bomb craters is represented by ellipses. A probabilistic approach based on marked point processes determines the most likely configuration of objects within the scene. Adding and removing new objects to and from the current configuration, respectively, changing their positions and modifying the ellipse parameters randomly creates new object configurations. Each configuration is evaluated using an energy function. High gradient magnitudes along the border of the ellipse are favored and overlapping ellipses are penalized. Reversible Jump Markov Chain Monte Carlo sampling in combination with simulated annealing provides the global energy optimum, which describes the conformance with a predefined model. For generating the impact map a probability map is defined which is created from the automatic detections via kernel density estimation. By setting a threshold, areas around the detections are classified as contaminated or uncontaminated sites, respectively. Our results show the general potential of the method for the automatic detection of bomb craters and its automated generation of an impact map in a heterogeneous image stock.

  9. A marked point process approach for identifying neural correlates of tics in Tourette Syndrome.

    Science.gov (United States)

    Loza, Carlos A; Shute, Jonathan B; Principe, Jose C; Okun, Michael S; Gunduz, Aysegul

    2017-07-01

    We propose a novel interpretation of local field potentials (LFP) based on a marked point process (MPP) framework that models relevant neuromodulations as shifted weighted versions of prototypical temporal patterns. Particularly, the MPP samples are categorized according to the well known oscillatory rhythms of the brain in an effort to elucidate spectrally specific behavioral correlates. The result is a transient model for LFP. We exploit data-driven techniques to fully estimate the model parameters with the added feature of exceptional temporal resolution of the resulting events. We utilize the learned features in the alpha and beta bands to assess correlations to tic events in patients with Tourette Syndrome (TS). The final results show stronger coupling between LFP recorded from the centromedian-paraficicular complex of the thalamus and the tic marks, in comparison to electrocorticogram (ECoG) recordings from the hand area of the primary motor cortex (M1) in terms of the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

  10. An Optimized Multicolor Point-Implicit Solver for Unstructured Grid Applications on Graphics Processing Units

    Science.gov (United States)

    Zubair, Mohammad; Nielsen, Eric; Luitjens, Justin; Hammond, Dana

    2016-01-01

    In the field of computational fluid dynamics, the Navier-Stokes equations are often solved using an unstructuredgrid approach to accommodate geometric complexity. Implicit solution methodologies for such spatial discretizations generally require frequent solution of large tightly-coupled systems of block-sparse linear equations. The multicolor point-implicit solver used in the current work typically requires a significant fraction of the overall application run time. In this work, an efficient implementation of the solver for graphics processing units is proposed. Several factors present unique challenges to achieving an efficient implementation in this environment. These include the variable amount of parallelism available in different kernel calls, indirect memory access patterns, low arithmetic intensity, and the requirement to support variable block sizes. In this work, the solver is reformulated to use standard sparse and dense Basic Linear Algebra Subprograms (BLAS) functions. However, numerical experiments show that the performance of the BLAS functions available in existing CUDA libraries is suboptimal for matrices representative of those encountered in actual simulations. Instead, optimized versions of these functions are developed. Depending on block size, the new implementations show performance gains of up to 7x over the existing CUDA library functions.

  11. Plasmon point spread functions: How do we model plasmon-mediated emission processes?

    Science.gov (United States)

    Willets, Katherine A.

    2014-02-01

    A major challenge with studying plasmon-mediated emission events is the small size of plasmonic nanoparticles relative to the wavelength of light. Objects smaller than roughly half the wavelength of light will appear as diffraction-limited spots in far-field optical images, presenting a significant experimental challenge for studying plasmonic processes on the nanoscale. Super-resolution imaging has recently been applied to plasmonic nanosystems and allows plasmon-mediated emission to be resolved on the order of ˜5 nm. In super-resolution imaging, a diffraction-limited spot is fit to some model function in order to calculate the position of the emission centroid, which represents the location of the emitter. However, the accuracy of the centroid position strongly depends on how well the fitting function describes the data. This Perspective discusses the commonly used two-dimensional Gaussian fitting function applied to super-resolution imaging of plasmon-mediated emission, then introduces an alternative model based on dipole point spread functions. The two fitting models are compared and contrasted for super-resolution imaging of nanoparticle scattering/luminescence, surface-enhanced Raman scattering, and surface-enhanced fluorescence.

  12. ISRIA statement: ten-point guidelines for an effective process of research impact assessment.

    Science.gov (United States)

    Adam, Paula; Ovseiko, Pavel V; Grant, Jonathan; Graham, Kathryn E A; Boukhris, Omar F; Dowd, Anne-Maree; Balling, Gert V; Christensen, Rikke N; Pollitt, Alexandra; Taylor, Mark; Sued, Omar; Hinrichs-Krapels, Saba; Solans-Domènech, Maite; Chorzempa, Heidi

    2018-02-08

    As governments, funding agencies and research organisations worldwide seek to maximise both the financial and non-financial returns on investment in research, the way the research process is organised and funded is becoming increasingly under scrutiny. There are growing demands and aspirations to measure research impact (beyond academic publications), to understand how science works, and to optimise its societal and economic impact. In response, a multidisciplinary practice called research impact assessment is rapidly developing. Given that the practice is still in its formative stage, systematised recommendations or accepted standards for practitioners (such as funders and those responsible for managing research projects) across countries or disciplines to guide research impact assessment are not yet available.In this statement, we propose initial guidelines for a rigorous and effective process of research impact assessment applicable to all research disciplines and oriented towards practice. This statement systematises expert knowledge and practitioner experience from designing and delivering the International School on Research Impact Assessment (ISRIA). It brings together insights from over 450 experts and practitioners from 34 countries, who participated in the school during its 5-year run (from 2013 to 2017) and shares a set of core values from the school's learning programme. These insights are distilled into ten-point guidelines, which relate to (1) context, (2) purpose, (3) stakeholders' needs, (4) stakeholder engagement, (5) conceptual frameworks, (6) methods and data sources, (7) indicators and metrics, (8) ethics and conflicts of interest, (9) communication, and (10) community of practice.The guidelines can help practitioners improve and standardise the process of research impact assessment, but they are by no means exhaustive and require evaluation and continuous improvement. The prima facie effectiveness of the guidelines is based on the systematised

  13. Point process models for localization and interdependence of punctate cellular structures.

    Science.gov (United States)

    Li, Ying; Majarian, Timothy D; Naik, Armaghan W; Johnson, Gregory R; Murphy, Robert F

    2016-07-01

    Accurate representations of cellular organization for multiple eukaryotic cell types are required for creating predictive models of dynamic cellular function. To this end, we have previously developed the CellOrganizer platform, an open source system for generative modeling of cellular components from microscopy images. CellOrganizer models capture the inherent heterogeneity in the spatial distribution, size, and quantity of different components among a cell population. Furthermore, CellOrganizer can generate quantitatively realistic synthetic images that reflect the underlying cell population. A current focus of the project is to model the complex, interdependent nature of organelle localization. We built upon previous work on developing multiple non-parametric models of organelles or structures that show punctate patterns. The previous models described the relationships between the subcellular localization of puncta and the positions of cell and nuclear membranes and microtubules. We extend these models to consider the relationship to the endoplasmic reticulum (ER), and to consider the relationship between the positions of different puncta of the same type. Our results do not suggest that the punctate patterns we examined are dependent on ER position or inter- and intra-class proximity. With these results, we built classifiers to update previous assignments of proteins to one of 11 patterns in three distinct cell lines. Our generative models demonstrate the ability to construct statistically accurate representations of puncta localization from simple cellular markers in distinct cell types, capturing the complex phenomena of cellular structure interaction with little human input. This protocol represents a novel approach to vesicular protein annotation, a field that is often neglected in high-throughput microscopy. These results suggest that spatial point process models provide useful insight with respect to the spatial dependence between cellular structures.

  14. Bubble point pressures of the selected model system for CatLiq® bio-oil process

    DEFF Research Database (Denmark)

    Toor, Saqib Sohail; Rosendahl, Lasse; Baig, Muhammad Noman

    2010-01-01

    . In this work, the bubble point pressures of a selected model mixture (CO2 + H2O + Ethanol + Acetic acid + Octanoic acid) were measured to investigate the phase boundaries of the CatLiq® process. The bubble points were measured in the JEFRI-DBR high pressure PVT phase behavior system. The experimental results......The CatLiq® process is a second generation catalytic liquefaction process for the production of bio-oil from WDGS (Wet Distillers Grains with Solubles) at subcritical conditions (280-350 oC and 225-250 bar) in the presence of a homogeneous alkaline and a heterogeneous Zirconia catalyst...

  15. Structured Spatio-temporal shot-noise Cox point process models, with a view to modelling forest fires

    DEFF Research Database (Denmark)

    Møller, Jesper; Diaz-Avalos, Carlos

    2010-01-01

    Spatio-temporal Cox point process models with a multiplicative structure for the driving random intensity, incorporating covariate information into temporal and spatial components, and with a residual term modelled by a shot-noise process, are considered. Such models are flexible and tractable fo...... data set consisting of 2796 days and 5834 spatial locations of fires. The model is compared with a spatio-temporal log-Gaussian Cox point process model, and likelihood-based methods are discussed to some extent....

  16. Strong approximations and sequential change-point analysis for diffusion processes

    DEFF Research Database (Denmark)

    Mihalache, Stefan-Radu

    2012-01-01

    In this paper ergodic diffusion processes depending on a parameter in the drift are considered under the assumption that the processes can be observed continuously. Strong approximations by Wiener processes for a stochastic integral and for the estimator process constructed by the one...

  17. Concerning the acid dew point in waste gases from combustion processes

    Energy Technology Data Exchange (ETDEWEB)

    Knoche, K.F.; Deutz, W.; Hein, K.; Derichs, W.

    1986-09-01

    The paper discusses the problems associated with the measurement of acid dew point and of sulphuric acid-(say SO/sub 3/-)concentrations in the flue gas from brown coal-fired boiler plants. The sulphuric acid content in brown coal flue gas has been measured at 0.5 to 3 vpm in SO/sub 2/ concentrations of 200 to 800 vpm. Using a conditional equation, the derivation of which from new formulae for phase stability is described in the paper, an acid dew point temperature of 115 to 125/sup 0/C is produced.

  18. Comparison of Clothing Cultures from the View Point of Funeral Procession

    OpenAIRE

    増田, 美子; 大枝, 近子; 梅谷, 知世; 杉本, 浄; 内村, 理奈

    2011-01-01

    This study was for its object to research for the look in the funeral ceremony and make the point of the different and common point between the respective cultural spheres of the Buddhism,Hinduism, Islam and Christianity clearly. In the year 21, we tried to grasp the reality of costumes of funeral courtesy in modern times and present-day. And it became clear in the result, Japan, the Buddhist cultural sphere, China and Taiwan, the Buddhism, the Confucianism and the Taoism intermingled cultura...

  19. Fixed-point Characterization of Compositionality Properties of Probabilistic Processes Combinators

    Directory of Open Access Journals (Sweden)

    Daniel Gebler

    2014-08-01

    Full Text Available Bisimulation metric is a robust behavioural semantics for probabilistic processes. Given any SOS specification of probabilistic processes, we provide a method to compute for each operator of the language its respective metric compositionality property. The compositionality property of an operator is defined as its modulus of continuity which gives the relative increase of the distance between processes when they are combined by that operator. The compositionality property of an operator is computed by recursively counting how many times the combined processes are copied along their evolution. The compositionality properties allow to derive an upper bound on the distance between processes by purely inspecting the operators used to specify those processes.

  20. Focal Points, Endogenous Processes, and Exogenous Shocks in the Autism Epidemic

    Science.gov (United States)

    Liu, Kayuet; Bearman, Peter S.

    2015-01-01

    Autism prevalence has increased rapidly in the United States during the past two decades. We have previously shown that the diffusion of information about autism through spatially proximate social relations has contributed significantly to the epidemic. This study expands on this finding by identifying the focal points for interaction that drive…

  1. Multiscale change-point analysis of inhomogeneous Poisson processes using unbalanced wavelet decompositions

    NARCIS (Netherlands)

    Jansen, M.H.; Di Bucchianico, A.; Mattheij, R.M.M.; Peletier, M.A.

    2006-01-01

    We present a continuous wavelet analysis of count data with timevarying intensities. The objective is to extract intervals with significant intensities from background intervals. This includes the precise starting point of the significant interval, its exact duration and the (average) level of

  2. Non-colliding Brownian Motions and the Extended Tacnode Process

    Science.gov (United States)

    Johansson, Kurt

    2013-04-01

    We consider non-colliding Brownian motions with two starting points and two endpoints. The points are chosen so that the two groups of Brownian motions just touch each other, a situation that is referred to as a tacnode. The extended kernel for the determinantal point process at the tacnode point is computed using new methods and given in a different form from that obtained for a single time in previous work by Delvaux, Kuijlaars and Zhang. The form of the extended kernel is also different from that obtained for the extended tacnode kernel in another model by Adler, Ferrari and van Moerbeke. We also obtain the correlation kernel for a finite number of non-colliding Brownian motions starting at two points and ending at arbitrary points.

  3. Phase-equilibria for design of coal-gasification processes: dew points of hot gases containing condensible tars. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Prausnitz, J.M.

    1980-05-01

    This research is concerned with the fundamental physical chemistry and thermodynamics of condensation of tars (dew points) from the vapor phase at advanced temperatures and pressures. Fundamental quantitative understanding of dew points is important for rational design of heat exchangers to recover sensible heat from hot, tar-containing gases that are produced in coal gasification. This report includes essentially six contributions toward establishing the desired understanding: (1) Characterization of Coal Tars for Dew-Point Calculations; (2) Fugacity Coefficients for Dew-Point Calculations in Coal-Gasification Process Design; (3) Vapor Pressures of High-Molecular-Weight Hydrocarbons; (4) Estimation of Vapor Pressures of High-Boiling Fractions in Liquefied Fossil Fuels Containing Heteroatoms Nitrogen or Sulfur; and (5) Vapor Pressures of Heavy Liquid Hydrocarbons by a Group-Contribution Method.

  4. Simultaneous reconstruction of multiple depth images without off-focus points in integral imaging using a graphics processing unit.

    Science.gov (United States)

    Yi, Faliu; Lee, Jieun; Moon, Inkyu

    2014-05-01

    The reconstruction of multiple depth images with a ray back-propagation algorithm in three-dimensional (3D) computational integral imaging is computationally burdensome. Further, a reconstructed depth image consists of a focus and an off-focus area. Focus areas are 3D points on the surface of an object that are located at the reconstructed depth, while off-focus areas include 3D points in free-space that do not belong to any object surface in 3D space. Generally, without being removed, the presence of an off-focus area would adversely affect the high-level analysis of a 3D object, including its classification, recognition, and tracking. Here, we use a graphics processing unit (GPU) that supports parallel processing with multiple processors to simultaneously reconstruct multiple depth images using a lookup table containing the shifted values along the x and y directions for each elemental image in a given depth range. Moreover, each 3D point on a depth image can be measured by analyzing its statistical variance with its corresponding samples, which are captured by the two-dimensional (2D) elemental images. These statistical variances can be used to classify depth image pixels as either focus or off-focus points. At this stage, the measurement of focus and off-focus points in multiple depth images is also implemented in parallel on a GPU. Our proposed method is conducted based on the assumption that there is no occlusion of the 3D object during the capture stage of the integral imaging process. Experimental results have demonstrated that this method is capable of removing off-focus points in the reconstructed depth image. The results also showed that using a GPU to remove the off-focus points could greatly improve the overall computational speed compared with using a CPU.

  5. Second-order analysis of inhomogeneous spatial point processes with proportional intensity functions

    DEFF Research Database (Denmark)

    Guan, Yongtao; Waagepetersen, Rasmus; Beale, Colin M.

    2008-01-01

    of the intensity functions. The first approach is based on nonparametric kernel-smoothing, whereas the second approach uses a conditional likelihood estimation approach to fit a parametric model for the pair correlation function. A great advantage of the proposed methods is that they do not require the often...... to two spatial point patterns regarding the spatial distributions of birds in the U.K.'s Peak District in 1990 and 2004....

  6. Fractal Point Process and Queueing Theory and Application to Communication Networks

    National Research Council Canada - National Science Library

    Wornel, Gregory

    1999-01-01

    .... A unifying theme in the approaches to these problems has been an integration of interrelated perspectives from communication theory, information theory, signal processing theory, and control theory...

  7. Process of extracting oil from stones and sands. [heating below cracking temperature and above boiling point of oil

    Energy Technology Data Exchange (ETDEWEB)

    Bergfeld, K

    1935-03-09

    A process of extracting oil from stones or sands bearing oils is characterized by the stones and sands being heated in a suitable furnace to a temperature below that of cracking and preferably slightly higher than the boiling-point of the oils. The oily vapors are removed from the treating chamber by means of flushing gas.

  8. A three-dimensional point process model for the spatial distribution of disease occurrence in relation to an exposure source

    DEFF Research Database (Denmark)

    Grell, Kathrine; Diggle, Peter J; Frederiksen, Kirsten

    2015-01-01

    We study methods for how to include the spatial distribution of tumours when investigating the relation between brain tumours and the exposure from radio frequency electromagnetic fields caused by mobile phone use. Our suggested point process model is adapted from studies investigating spatial...... the Interphone Study, a large multinational case-control study on the association between brain tumours and mobile phone use....

  9. Estimating functions for inhomogeneous spatial point processes with incomplete covariate data

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus

    and this leads to parameter estimation error which is difficult to quantify. In this paper we introduce a Monte Carlo version of the estimating function used in "spatstat" for fitting inhomogeneous Poisson processes and certain inhomogeneous cluster processes. For this modified estimating function it is feasible...

  10. Estimating functions for inhomogeneous spatial point processes with incomplete covariate data

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus

    2008-01-01

    and this leads to parameter estimation error which is difficult to quantify. In this paper, we introduce a Monte Carlo version of the estimating function used in spatstat for fitting inhomogeneous Poisson processes and certain inhomogeneous cluster processes. For this modified estimating function, it is feasible...

  11. Hazard rate model and statistical analysis of a compound point process

    Czech Academy of Sciences Publication Activity Database

    Volf, Petr

    2005-01-01

    Roč. 41, č. 6 (2005), s. 773-786 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GA402/04/1294 Institutional research plan: CEZ:AV0Z10750506 Keywords : couting process * compound process * Cox regression model * intensity Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.343, year: 2005

  12. Congruence from the operator's point of view: compositionality requirements on process semantics

    NARCIS (Netherlands)

    Gazda, M.; Fokkink, W.J.

    2010-01-01

    One of the basic sanity properties of a behavioural semantics is that it constitutes a congruence with respect to standard process operators. This issue has been traditionally addressed by the development of rule formats for transition system specifications that define process algebras. In this

  13. Congruence from the operator's point of view : compositionality requirements on process semantics

    NARCIS (Netherlands)

    Gazda, M.W.; Fokkink, W.J.; Aceto, L.; Sobocinski, P.

    2010-01-01

    One of the basic sanity properties of a behavioural semantics is that it constitutes a congruence with respect to standard process operators. This issue has been traditionally addressed by the development of rule formats for transition system specifications that define process algebras. In this

  14. Análisis de los factores determinantes de la cultura organizacional en el ambiente empresarial

    Directory of Open Access Journals (Sweden)

    José Morelos-Gómez

    2014-01-01

    Full Text Available El presente artículo muestra el análisis de los factores determinantes de la cultura organizacional en el ambiente empresarial y la incidencia de estos condicionantes del entorno en los cambios internos y el comportamiento de colaboradores y directivos. Para la revisión documental se analizaron los conceptos de cultura organizacional y los factores determinantes de un total de 55 artículos relacionados con la pertinencia del referente teórico, resultados y experiencias registrados en investigaciones que aportaron nuevo conocimiento científico de interés para los grupos de organizaciones. Los resultados permiten identificar la importancia de los determinantes estrategia, estructura, trabajo en grupo, estilo de liderazgo de los managers, características organizacionales, fundadores y propietarios y ambiente organizacional, para la consecución de los objetivos y la generación de valor en las empresas.

  15. Estudio transversal de los determinantes del trabajo infantil en Cartagena, año 2007

    Directory of Open Access Journals (Sweden)

    Karina Acevedo

    2011-01-01

    Full Text Available El trabajo infantil constituye una problemática compleja que tiene importantes repercusiones en las reservas de capital humano, en la salud de los niños y niñas, y en la persistencia de la pobreza. Nuestro principal objetivo en este artículo es dilucidar sus determinantes en la ciudad de Cartagena a través de la estimación de un modelo probit bivariado, con el cual analizamos conjuntamente las decisiones de trabajo y de asistencia escolar. Los resultados muestran que el trabajo infantil y la asistencia escolar son actividades excluyentes, siendo los determinantes más robustos de estas decisiones la educación del jefe de hogar, y la pobreza. Entre otros determinantes se encuentran las restricciones crediticias, la proximidad física a las escuelas y la tasa de ocupación de las personas adultas.

  16. Scientific evidence is just the starting point: A generalizable process for developing sports injury prevention interventions

    Directory of Open Access Journals (Sweden)

    Alex Donaldson

    2016-09-01

    Conclusion: This systematic yet pragmatic and iterative intervention development process is potentially applicable to any injury prevention topic across all sports settings and levels. It will guide researchers wishing to undertake intervention development.

  17. Main points of research in crude oil processing and petrochemistry. [German Democratic Republic

    Energy Technology Data Exchange (ETDEWEB)

    Keil, G.; Nowak, S.; Fiedrich, G.; Klare, H.; Apelt, E.

    1982-04-01

    This article analyzes general aspects in the development of petrochemistry and carbochemistry on a global scale and for industry in the German Democratic Republic. Diagrams are given for liquid and solid carbon resources and their natural hydrogen content showing the increasing hydrogen demand for chemical fuel conversion processes. The petrochemical and carbochemical industry must take a growing level of hydrogen demand into account, which is at present 25 Mt/a on a global scale and which increases by 7% annually. Various methods for chemical processing of crude oil and crude oil residues are outlined. Advanced coal conversion processes with prospects for future application in the GDR are also explained, including the methanol carbonylation process, which achieves 90% selectivity and which is based on carbon monoxide hydrogenation, further the Transcat process, using ethane for vinyl chloride production. Acetylene and carbide carbochemistry in the GDR is a further major line in research and development. Technological processes for the pyrolysis of vacuum gas oil are also evaluated. (27 refs.)

  18. Factores determinantes de la contaminación ambiental y del uso de los recursos naturales

    OpenAIRE

    Klaus Georg Binder

    2002-01-01

    Dentro de los factores determinantes de la utilización contaminante del medio ambiente y del uso de los recursos naturales encontramos: el crecimiento demográfico, el desarrollo económico (crecimiento económico, cambio de la estructura económica, progreso técnico, etc.) y la concentración espacial de la población y su actividad económica. A causa de la interdependencia entre los factores determinantes de la utilización del medio ambiente, no se puede decir que el crecimiento económico en los ...

  19. Determinantes de la demanda por Educación Superior en cinco regiones de Colombia

    OpenAIRE

    Giraldo Giraldo, María Paulina; Pareja Giraldo, Lady Carolina

    2014-01-01

    Este artículo estudia algunos de los determinantes de la demanda por educación superior en cinco regiones de Colombia -- Se utiliza información de la gran encuesta integrada de hogares (GEIH) para estimar un modelo Logit dicotómico por cada región, haciendo uso de las variables sociales y personales identificadas como determinantes, permitiendo realizar un análisis comparativo entre estos -- Los resultados del estudio sugieren que la edad, el ingreso percápita en los hogares y la educación de...

  20. Modelling estimation and analysis of dynamic processes from image sequences using temporal random closed sets and point processes with application to the cell exocytosis and endocytosis

    OpenAIRE

    Díaz Fernández, Ester

    2010-01-01

    In this thesis, new models and methodologies are introduced for the analysis of dynamic processes characterized by image sequences with spatial temporal overlapping. The spatial temporal overlapping exists in many natural phenomena and should be addressed properly in several Science disciplines such as Microscopy, Material Sciences, Biology, Geostatistics or Communication Networks. This work is related to the Point Process and Random Closed Set theories, within Stochastic Ge...

  1. Steam generators secondary side chemical cleaning at Point Lepreau using the Siemens high temperature process

    International Nuclear Information System (INIS)

    Verma, K.; MacNeil, C.; Odar, S.; Kuhnke, K.

    1997-01-01

    This paper describes the chemical cleaning of the four steam generators at the Point Lepreau facility, which was accomplished as a part of a normal service outage. The steam generators had been in service for twelve years. Sludge samples showed the main elements were Fe, P and Na, with minor amounts of Ca, Mg, Mn, Cr, Zn, Cl, Cu, Ni, Ti, Si, and Pb, 90% in the form of Magnetite, substantial phosphate, and trace amounts of silicates. The steam generators were experiencing partial blockage of broached holes in the TSPs, and corrosion on tube ODs in the form of pitting and wastage. In addition heat transfer was clearly deteriorating. More than 1000 kg of magnetite and 124 kg of salts were removed from the four steam generators

  2. The role of point defects and defect complexes in silicon device processing. Summary report and papers

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B.; Tan, T.Y.

    1994-08-01

    This report is a summary of a workshop hold on August 24--26, 1992. Session 1 of the conference discussed characteristics of various commercial photovoltaic silicon substrates, the nature of impurities and defects in them, and how they are related to the material growth. Session 2 on point defects reviewed the capabilities of theoretical approaches to determine equilibrium structure of defects in the silicon lattice arising from transitional metal impurities and hydrogen. Session 3 was devoted to a discussion of the surface photovoltaic method for characterizing bulk wafer lifetimes, and to detailed studies on the effectiveness of various gettering operations on reducing the deleterious effects of transition metals. Papers presented at the conference are also included in this summary report.

  3. Congruence from the Operator's Point of View: Compositionality Requirements on Process Semantics

    Directory of Open Access Journals (Sweden)

    Maciej Gazda

    2010-08-01

    Full Text Available One of the basic sanity properties of a behavioural semantics is that it constitutes a congruence with respect to standard process operators. This issue has been traditionally addressed by the development of rule formats for transition system specifications that define process algebras. In this paper we suggest a novel, orthogonal approach. Namely, we focus on a number of process operators, and for each of them attempt to find the widest possible class of congruences. To this end, we impose restrictions on sublanguages of Hennessy-Milner logic, so that a semantics whose modal characterization satisfies a given criterion is guaranteed to be a congruence with respect to the operator in question. We investigate action prefix, alternative composition, two restriction operators, and parallel composition.

  4. Accuracy of heart rate variability estimation by photoplethysmography using an smartphone: Processing optimization and fiducial point selection.

    Science.gov (United States)

    Ferrer-Mileo, V; Guede-Fernandez, F; Fernandez-Chimeno, M; Ramos-Castro, J; Garcia-Gonzalez, M A

    2015-08-01

    This work compares several fiducial points to detect the arrival of a new pulse in a photoplethysmographic signal using the built-in camera of smartphones or a photoplethysmograph. Also, an optimization process for the signal preprocessing stage has been done. Finally we characterize the error produced when we use the best cutoff frequencies and fiducial point for smartphones and photopletysmograph and compare if the error of smartphones can be reasonably be explained by variations in pulse transit time. The results have revealed that the peak of the first derivative and the minimum of the second derivative of the pulse wave have the lowest error. Moreover, for these points, high pass filtering the signal between 0.1 to 0.8 Hz and low pass around 2.7 Hz or 3.5 Hz are the best cutoff frequencies. Finally, the error in smartphones is slightly higher than in a photoplethysmograph.

  5. Determinantes da folga organizacional em uma empresa com estrutura descentralizada.

    Directory of Open Access Journals (Sweden)

    Ilse Maria Beuren

    2015-08-01

    Full Text Available O objetivo do estudo é identificar os determinantes da folga organizacional em uma empresa com estrutura descentralizada, com ênfase no modo como os controllers das unidades de negócios afetam a folga. Foi realizada uma pesquisa descritiva com abordagem quantitativa, por meio de survey, utilizando o instrumento de pesquisa concebido por Indjejikian e Matëjka (2006, que se constitui de dois questionários, um para o gestor e outro para o controller de cada UN. A empresa objeto de estudo apresenta estrutura descentralizada com 45 UNs, das quais 32 responderam aos questionários. Os resultados da pesquisa indicam que as metas de desempenho, quando o crescimento das UNs é provocado pelo aumento das vendas e do market share, com sacrifício do retorno sobre o investimento no curto e médio prazos, são mais fáceis de alcançar e permitem maior folga organizacional do que em situações de UNs mais estáveis. Também indicam que a folga organizacional é maior em ambientes caracterizados por maior assimetria de informação entre a holding e os gestores das UNs, definidos pelo foco do controller da UN. Os resultados dos testes da relação entre as variáveis foco do controller da UN e folga organizacional evidenciam que os controllers das UNs priorizam o apoio à tomada de decisão na UN, em detrimento de suas responsabilidades com o sistema de controle gerencial corporativo. Quanto maior o tempo de atuação do controller na UN, maior é a sua dedicação às responsabilidades relacionadas à gestão da UN em detrimento do foco nas tarefas da holding. Conclui-se que a relação constatada nesta pesquisa entre o nível de folga organizacional e o foco dos controllers das UNs se coaduna com aquela enunciada no estudo de referência. De maneira geral, os resultados das análises estão alinhados com os da pesquisa de Indjejikian e Matëjka (2006, consideradas as limitações de comparabilidade em função das diferenças amostrais.

  6. Análise dos determinantes do endividamento das empresas de capital aberto do agronegócio brasileiro

    Directory of Open Access Journals (Sweden)

    Valéria Gama Fully Bressan

    2009-03-01

    Full Text Available Estudos sobre a estrutura de capital e a identificação de seus determinantes são temas relevantes nas pesquisas envolvendo a gestão financeira das empresas. Neste aspecto, o presente estudo teve como objetivo avaliar os determinantes da alavancagem das empresas do agronegócio brasileiro conforme o modelo de Rajan e Zingales (1995. Na definição da amostra, foram selecionadas 26 empresas que estavam enquadradas em alguma das três subdivisões do agronegócio brasileiro: a o setor de produção agropecuária; b setor fornecedor de insumos e fatores de produção e c setor de processamento e distribuição, com base em classificação da CNA (Confederação da Agricultura e Pecuária do Brasil. O estudo foi feito com base no banco de dados da Economática®, tendo sido utilizado o modelo de regressão com dados em painel. Os resultados indicaram que as variáveis tangibilidade dos ativos, oportunidadede crescimento, tamanho e lucratividade foram estatisticamente significantes e podem ser interpretadas como fatores determinantes do endividamento das empresas do agronegócio brasileiro. Conclui-se, ainda, que o modelo estimado por meio da regressão com dados em painel gerou resultado compatível com aqueles preconizados pela pecking order theory.Studies involving capital structure and the identification of its determinants are relevant issues in the field of corporate finance management research. In this regard, the present study intends to evaluate the determinants of corporate leverage in the Brazilian agribusiness sector using the model of Rajan and Zingales (1995. In the definition of the sample there were selected 26 companies that are classified in one of three subdivisions of the Brazilian agribusiness sector: a the agriculture or cattle raising; b inputs or production factors and c processing and distribution sector, using as reference the CNA classification. The study used data from the Economatica® database, with the adoption of

  7. A Traffic Model for Machine-Type Communications Using Spatial Point Processes

    DEFF Research Database (Denmark)

    Thomsen, Henning; Manchón, Carles Navarro; Fleury, Bernard Henri

    2018-01-01

    , where the generated traffic by a given device depends on its position and event positions. We first consider the case where devices and events are static and devices generate traffic according to a Bernoulli process, where we derive the total rate from the devices at the base station. We then extend...

  8. Bayesian analysis of spatial point processes in the neighbourhood of Voronoi networks

    DEFF Research Database (Denmark)

    Skare, Øivind; Møller, Jesper; Jensen, Eva Bjørn Vedel

    2007-01-01

    A model for an inhomogeneous Poisson process with high intensity near the edges of a Voronoi tessellation in 2D or 3D is proposed. The model is analysed in a Bayesian setting with priors on nuclei of the Voronoi tessellation and other model parameters. An MCMC algorithm is constructed to sample...

  9. Optimal estimation of the intensity function of a spatial point process

    DEFF Research Database (Denmark)

    Guan, Yongtao; Jalilian, Abdollah; Waagepetersen, Rasmus

    easily computable estimating functions. We derive the optimal estimating function in a class of first-order estimating functions. The optimal estimating function depends on the solution of a certain Fredholm integral equation and reduces to the likelihood score in case of a Poisson process. We discuss...

  10. Bayesian analysis of spatial point processes in the neighbourhood of Voronoi networks

    DEFF Research Database (Denmark)

    Skare, Øivind; Møller, Jesper; Vedel Jensen, Eva B.

    A model for an inhomogeneous Poisson process with high intensity near the edges of a Voronoi tessellation in 2D or 3D is proposed. The model is analysed in a Bayesian setting with priors on nuclei of the Voronoi tessellation and other model parameters. An MCMC algorithm is constructed to sample...

  11. Entry points to stimulation of expansion in hides and skins processing

    African Journals Online (AJOL)

    Only 3.4% of respondents add value to hides and skins by processing. ... For this status of the chain, it was proposed that a workable intervention model has to encompass placement of tanneries and slaughter slabs in the chain as new actors, linking chain actors, improving livestock services especially dipping, and ...

  12. Mentoring Novice Teachers: Motives, Process, and Outcomes from the Mentor's Point of View

    Science.gov (United States)

    Iancu-Haddad, Debbie; Oplatka, Izhar

    2009-01-01

    The purpose of this paper is to present the major motives leading senior teachers to be involved in a mentoring process of newly appointed teachers and its benefits for the mentor teacher. Based on semi-structured interviews with 12 experienced teachers who participated in a university-based mentoring program in Israel, the current study found a…

  13. Stressors and Turning Points in High School and Dropout: A Stress Process, Life Course Framework

    Science.gov (United States)

    Dupéré, Véronique; Leventhal, Tama; Dion, Eric; Crosnoe, Robert; Archambault, Isabelle; Janosz, Michel

    2015-01-01

    High school dropout is commonly seen as the result of a long-term process of failure and disengagement. As useful as it is, this view has obscured the heterogeneity of pathways leading to dropout. Research suggests, for instance, that some students leave school not as a result of protracted difficulties but in response to situations that emerge…

  14. La salud y sus determinantes sociales. Desigualdades y exclusión en la sociedad del siglo XXI

    Directory of Open Access Journals (Sweden)

    Palomino Moral, Pedro A.

    2014-06-01

    Full Text Available The health concept has undergone a process of constant revision. From the mid-twentieth century it has taken place a shift from the search for the causes of the disease focused on the individual to the emergence of health social determinants that are the main modulators of the health and disease processes. Today we know that health and quality of life are a social result directly related to the conditions of people´s life and way of life. In this sense it has been made significant efforts to understand how they interact with the social determinants and how health outcomes occur. We analyzed the contributions that have succeeded in highlighting the main factors of social inequalities including an analysis of inequalities in women’s health, vulnerability and risk of exclusion.El concepto de salud ha experimentado un proceso de revisión constante. Desde mediados del siglo XX se ha producido un desplazamiento desde la búsqueda de las causas de la enfermedad centradas en el individuo a la aparición de los determinantes sociales, los principales moduladores del fenómeno salud y la enfermedad. Hoy sabemos que la salud y la calidad de vida son un resultado social directamente relacionado con las condiciones generales de la vida de las personas y con la forma de vivir; en este sentido se han hecho notables esfuerzos en las últimas décadas para comprender cómo interactúan los determinantes sociales y se producen los resultados en salud. Analizamos las aportaciones que han conseguido poner de manifiesto los principales factores generadores de las desigualdades sociales incluyendo un análisis de las desigualdades en salud de las mujeres, la vulnerabilidad y el riesgo de exclusión.

  15. Meeting points in the VPL process - a key challenge for VPL activities

    DEFF Research Database (Denmark)

    Aagaard, Kirsten; Enggaard, Ellen

    2014-01-01

    , a step up the career ladder, personal development or threat of losing his job and the work place’s demand for new competences? There are three main players on this scene: the individual, the (HE) educational institution and the work place. There may be more players involved in the process......The right to have your competences recognized and validated as a mean to gain access to or exemptions of a higher education has existed since 2007, but the knowledge of this opportunity is still not very well spread and the potentials of the law are not exploited. This goes for individuals as well...... the individual in his or her individual career strategies benefit from the option of VPL in the process of managing his or her career strategy? What are the main barriers and obstacles the individual might meet in his or her attempt to move on in his career whether the motivation is change of career direction...

  16. Chosen Aspects of Modernization Processes in EU Countries and in Poland - Classical Point of View

    OpenAIRE

    Dworak Edyta; Malarska Anna

    2010-01-01

    The aim of this paper is an evaluation of changes in a sectoral structure of the employment in EU-countries in time. Against this background there are exposed changes in Polish economy in the period 1997-2008. There were used classical tools of the statistical analysis to illustrate and initially verification the theory of three sectors by A. Fisher, C. Clark i J. Fourastiè, orientated to the evaluation of the modernization process of EU-economies.

  17. The Development of Point Doppler Velocimeter Data Acquisition and Processing Software

    Science.gov (United States)

    Cavone, Angelo A.

    2008-01-01

    In order to develop efficient and quiet aircraft and validate Computational Fluid Dynamic predications, aerodynamic researchers require flow parameter measurements to characterize flow fields about wind tunnel models and jet flows. A one-component Point Doppler Velocimeter (pDv), a non-intrusive, laser-based instrument, was constructed using a design/develop/test/validate/deploy approach. A primary component of the instrument is software required for system control/management and data collection/reduction. This software along with evaluation algorithms, advanced pDv from a laboratory curiosity to a production level instrument. Simultaneous pDv and pitot probe velocity measurements obtained at the centerline of a flow exiting a two-inch jet, matched within 0.4%. Flow turbulence spectra obtained with pDv and a hot-wire detected the primary and secondary harmonics with equal dynamic range produced by the fan driving the flow. Novel,hardware and software methods were developed, tested and incorporated into the system to eliminate and/or minimize error sources and improve system reliability.

  18. From Takeoff to Landing: Looking at the Design Process for the Development of NASA Blast at Thanksgiving Point

    Directory of Open Access Journals (Sweden)

    Stephen Ashton

    2011-01-01

    Full Text Available In this article we discuss the process of design used to develop and design the NASA Blast exhibition at Thanksgiving Point, a museum complex in Lehi, Utah. This was a class project for the Advanced Instructional Design Class at Brigham Young University. In an attempt to create a new discourse (Krippendorff, 2006 for Thanksgiving Point visitors and staff members, the design class used a very fluid design approach by utilizing brainstorming, researching, class member personas, and prototyping to create ideas for the new exhibition. Because of the nature of the experience, the design class developed their own techniques to enhance the process of their design. The result of the design was a compelling narrative that brought all the elements of the exhibition together in a cohesive piece.

  19. Monte Carlo point process estimation of electromyographic envelopes from motor cortical spikes for brain-machine interfaces

    Science.gov (United States)

    Liao, Yuxi; She, Xiwei; Wang, Yiwen; Zhang, Shaomin; Zhang, Qiaosheng; Zheng, Xiaoxiang; Principe, Jose C.

    2015-12-01

    Objective. Representation of movement in the motor cortex (M1) has been widely studied in brain-machine interfaces (BMIs). The electromyogram (EMG) has greater bandwidth than the conventional kinematic variables (such as position, velocity), and is functionally related to the discharge of cortical neurons. As the stochastic information of EMG is derived from the explicit spike time structure, point process (PP) methods will be a good solution for decoding EMG directly from neural spike trains. Previous studies usually assume linear or exponential tuning curves between neural firing and EMG, which may not be true. Approach. In our analysis, we estimate the tuning curves in a data-driven way and find both the traditional functional-excitatory and functional-inhibitory neurons, which are widely found across a rat’s motor cortex. To accurately decode EMG envelopes from M1 neural spike trains, the Monte Carlo point process (MCPP) method is implemented based on such nonlinear tuning properties. Main results. Better reconstruction of EMG signals is shown on baseline and extreme high peaks, as our method can better preserve the nonlinearity of the neural tuning during decoding. The MCPP improves the prediction accuracy (the normalized mean squared error) 57% and 66% on average compared with the adaptive point process filter using linear and exponential tuning curves respectively, for all 112 data segments across six rats. Compared to a Wiener filter using spike rates with an optimal window size of 50 ms, MCPP decoding EMG from a point process improves the normalized mean square error (NMSE) by 59% on average. Significance. These results suggest that neural tuning is constantly changing during task execution and therefore, the use of spike timing methodologies and estimation of appropriate tuning curves needs to be undertaken for better EMG decoding in motor BMIs.

  20. The effect of starting point placement technique on thoracic transverse process strength: an ex vivo biomechanical study

    Directory of Open Access Journals (Sweden)

    Burton Douglas C

    2010-07-01

    Full Text Available Abstract Background The use of thoracic pedicle screws in spinal deformity, trauma, and tumor reconstruction is becoming more common. Unsuccessful screw placement may require salvage techniques utilizing transverse process hooks. The effect of different starting point placement techniques on the strength of the transverse process has not previously been reported. The purpose of this paper is to determine the biomechanical properties of the thoracic transverse process following various pedicle screw starting point placement techniques. Methods Forty-seven fresh-frozen human cadaveric thoracic vertebrae from T2 to T9 were disarticulated and matched by bone mineral density (BMD and transverse process (TP cross-sectional area. Specimens were randomized to one of four groups: A, control, and three others based on thoracic pedicle screw placement technique; B, straightforward; C, funnel; and D, in-out-in. Initial cortical bone removal for pedicle screw placement was made using a burr at the location on the transverse process or transverse process-laminar junction as published in the original description of each technique. The transverse process was tested measuring load-to-failure simulating a hook in compression mode. Analysis of covariance and Pearson correlation coefficients were used to examine the data. Results Technique was a significant predictor of load-to-failure (P = 0.0007. The least squares mean (LS mean load-to-failure of group A (control was 377 N, group B (straightforward 355 N, group C (funnel 229 N, and group D (in-out-in 301 N. Significant differences were noted between groups A and C, A and D, B and C, and C and D. BMD (0.925 g/cm2 [range, 0.624-1.301 g/cm2] was also a significant predictor of load-to-failure, for all specimens grouped together (P P 0.05. Level and side tested were not found to significantly correlate with load-to-failure. Conclusions The residual coronal plane compressive strength of the thoracic transverse process

  1. Design and fabrication of a diffractive beam splitter for dual-wavelength and concurrent irradiation of process points.

    Science.gov (United States)

    Amako, Jun; Shinozaki, Yu

    2016-07-11

    We report on a dual-wavelength diffractive beam splitter designed for use in parallel laser processing. This novel optical element generates two beam arrays of different wavelengths and allows their overlap at the process points on a workpiece. To design the deep surface-relief profile of a splitter using a simulated annealing algorithm, we introduce a heuristic but practical scheme to determine the maximum depth and the number of quantization levels. The designed corrugations were fabricated in a photoresist by maskless grayscale exposure using a high-resolution spatial light modulator. We characterized the photoresist splitter, thereby validating the proposed beam-splitting concept.

  2. Determinantes do desenvolvimento do setor agropecuário nos municípios Determinantes del desarrollo del sector agrícola-ganadero en los municipios Determinants of the development of the agricultural sector in municipalities

    Directory of Open Access Journals (Sweden)

    Caio César de Medeiros Costa

    2013-06-01

    Full Text Available Dada a importância do setor agropecuário para a economia brasileira, é fundamental conhecer os fatores determinantes do desenvolvimento agropecuário em seus municípios. Sob a luz de referencial teórico que aborda questões relacionadas aos fatores determinantes do desenvolvimento agropecuário e do desenvolvimento econômico local, neste estudo fez-se uso das metodologias de análise multivariada conhecidas como análise fatorial e análise de cluster. Utilizou-se o estado de Minas Gerais como recorte analítico. Foram selecionadas 22 variáveis para cada município, representando diferentes dimensões do desenvolvimento, visando verificar quais os fatores determinantes do desenvolvimento agropecuário. Após a análise fatorial, optou-se pela extração de seis fatores com raiz característica maior do que um e que respondem, em conjunto, por 62,25% da variância total dos dados: desenvolvimento econômico, investimento público, qualidade de vida, condições da atividade agropecuária, condições de meio ambiente e consumo, e condições de financiamento. Pela análise de cluster, foram criados cinco grupos, de acordo com o desempenho dos membros nos fatores. Os resultados corroboram os apontamentos literários em quase sua totalidade e, além disso, destaca-se e discute-se a existência de um ciclo positivo gerado pelo incremento dos fatores determinantes do desenvolvimento agropecuário e pelas vantagens competitivas. Neste estudo, aponta-se a importância do investimento público na promoção do desenvolvimento, reforçando o proposto por trabalhos anteriores de que o Estado desempenha papel fundamental para garantir condições que propiciem o desenvolvimento do setor agropecuário. Outra constatação factível é a de que fatores isolados, tais como as boas condições da agricultura e do meio ambiente, não são capazes de propiciar desenvolvimento para o setor nos municípios mineiros.Dada la importancia de la agricultura y de

  3. Can the Hazard Assessment and Critical Control Points (HACCP) system be used to design process-based hygiene concepts?

    Science.gov (United States)

    Hübner, N-O; Fleßa, S; Haak, J; Wilke, F; Hübner, C; Dahms, C; Hoffmann, W; Kramer, A

    2011-01-01

    Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible and will probably not readily yield the intended results, the underlying principles of process-orientation, in-process safety control and hazard analysis based counter measures are transferable to clinical settings. In model projects the proposed concepts should be implemented, monitored, and evaluated under real world conditions.

  4. Mass customization process for the Social Housing. Potentiality, critical points, research lines

    Directory of Open Access Journals (Sweden)

    Michele Di Sivo

    2012-10-01

    Full Text Available The demand for lengthening the life cycle of the residential estate, engendered with the economical and housing crisis since the last few years, brings out, in the course of time, the need for conservation and improvement works of the property house performances, through the direct involvement of the users. The possibility of reducing maintenance and adjustment costs may develop into a project resource, consistent to the participation and cooperation principles, identifying social housing interventions. With this aim, the BETHA group of the d’Annunzio University is investigating the potentiality of technological transfer of the ‘mass customization’ process from the industrial products field to the social housing segment, by detecting issues, strategies and opportunities.

  5. Stochastic dynamical model of a growing citation network based on a self-exciting point process.

    Science.gov (United States)

    Golosovsky, Michael; Solomon, Sorin

    2012-08-31

    We put under experimental scrutiny the preferential attachment model that is commonly accepted as a generating mechanism of the scale-free complex networks. To this end we chose a citation network of physics papers and traced the citation history of 40,195 papers published in one year. Contrary to common belief, we find that the citation dynamics of the individual papers follows the superlinear preferential attachment, with the exponent α=1.25-1.3. Moreover, we show that the citation process cannot be described as a memoryless Markov chain since there is a substantial correlation between the present and recent citation rates of a paper. Based on our findings we construct a stochastic growth model of the citation network, perform numerical simulations based on this model and achieve an excellent agreement with the measured citation distributions.

  6. Oportunismo como determinante da estrutura de capital: Um estudo de caso em nanotecnologia

    Directory of Open Access Journals (Sweden)

    Milena de Cassia Rocha

    2017-06-01

    Full Text Available A discussão sobre os determinantes da estrutura de capital é algo que vem sendo realizado há algum tempo. Contudo, é observado uma lacuna a respeito do tema em empresas de nanotecnologia, assim como trabalhos que enfoquem a ideia do oportunismo como determinante da estrutura de capital. Sendo assim, o presente artigo traz uma discussão sobre a ideia do oportunismo como determinante da estrutura de capital em empresas de nanotecnologia no Brasil. Para tal, foi realizado um estudo de caso abordando aspectos ligados a estrutura de capital adotada, a verificação da utilização de determinadas teorias sobre o tema e a relevância de algumas fontes. Foi observado que a empresa analisada utiliza a ideia do oportunismo como determinante da estrutura de capital devido aos fatores relacionados ao custo das fontes e as exigências por parte dos credores. Assim, em momentos em que os custos e as exigências são aceitáveis, para a empresa, se opta por tais fontes.

  7. PET and diagnostic technology evaluation in a global clinical process. DGN's point of view

    International Nuclear Information System (INIS)

    Kotzerke, J.; Dietlein, M.; Gruenwald, F.; Bockisch, A.

    2010-01-01

    The German Society of Nuclear Medicine (DGN) criticizes the methodological approach of the IQWiG for evaluation of PET and the conclusions, which represent the opposite point of view compared to the most other European countries and health companies in the USA: (1) Real integration of experienced physicians into the interpretation of data and the evaluation of effectiveness should be used for best possible reporting instead of only formal hearing. (2) Data of the National Oncologic PET Registry (NOPR) from the USA have shown, that PET has changed the therapeutic management in 38% of patients. (3) The decision of the IQWiG to accept outcome data only for their benefit analyses, is controversial. Medical knowledge is generated by different methods, and an actual analysis of the scientific guidelines has shown that only 15% out of all guidelines are based on the level of evidence demanded by the IQWiG. Health economics has created different assessment methods for the evaluation of a diagnostic procedure. The strategy chosen by the IQWiG overestimated the perspective of the population and undervalue the benefit for an individual patient. (4) PET evaluates the effectiveness of a therapeutic procedure, but does not create an effective therapy. When the predictive value of PET is already implemented in a specific study design and the result of PET define a specific management, the trial evaluate the whole algorithm and PET is part of this algorithm only. When PET is implemented as test during chemotherapy or by the end of chemotherapy, the predictive value of PET will depend decisively on the effectiveness of the therapy: The better the therapy, the smaller the differences in survival detected by PET. (5) The significance of an optimal staging by the integration of PET will increase. Rationale is the actual development of ''titration'' of chemotherapy intensity and radiation dose towards the lowest possible, just about effective dosage. (6) The medical therapy of

  8. [Pharmaceutical Assistance in the Family Healthcare Program: points of affinity and discord in the organization process].

    Science.gov (United States)

    Silva Oliveira, Tatiana de Alencar; Maria, Tatiane de Oliveira Silva; Alves do Nascimento, Angela Maria; do Nascimento, Angela Alves

    2011-09-01

    The scope of this study was to discuss the organization of the pharmaceutical assistance service in the family healthcare program. Qualitative research from a critical/analytical perspective was conducted in family healthcare units in a municipality of the state of Bahia, Brazil. Data was collected on the basis of systematic observation, semi-structured interviews and documents analysis from a dialectic standpoint. The organization of Pharmaceutical Assistance consisted of selection, planning, acquisition, storage and dispensing activities. The process was studied in the implementation phase, which was occurring in a centralized and uncoordinated fashion, without the proposed team work. An excess of activity was observed among the healthcare workers and there was an absence of a continued education policy for the workers. For the transformation of this situation and to ensure the organization of pharmaceutical assistance with quality and in an integrated manner, a reworking of the manner of thinking and action of the players concerned (managers, health workers and users), who participate directly in the organization, is necessary. Furthermore, mechanical, bureaucratic and impersonal work practices need to be abandoned.

  9. Aftershock identification problem via the nearest-neighbor analysis for marked point processes

    Science.gov (United States)

    Gabrielov, A.; Zaliapin, I.; Wong, H.; Keilis-Borok, V.

    2007-12-01

    The centennial observations on the world seismicity have revealed a wide variety of clustering phenomena that unfold in the space-time-energy domain and provide most reliable information about the earthquake dynamics. However, there is neither a unifying theory nor a convenient statistical apparatus that would naturally account for the different types of seismic clustering. In this talk we present a theoretical framework for nearest-neighbor analysis of marked processes and obtain new results on hierarchical approach to studying seismic clustering introduced by Baiesi and Paczuski (2004). Recall that under this approach one defines an asymmetric distance D in space-time-energy domain such that the nearest-neighbor spanning graph with respect to D becomes a time- oriented tree. We demonstrate how this approach can be used to detect earthquake clustering. We apply our analysis to the observed seismicity of California and synthetic catalogs from ETAS model and show that the earthquake clustering part is statistically different from the homogeneous part. This finding may serve as a basis for an objective aftershock identification procedure.

  10. Archiving, sharing, processing and publishing historical earthquakes data: the IT point of view

    Science.gov (United States)

    Locati, Mario; Rovida, Andrea; Albini, Paola

    2014-05-01

    Digital tools devised for seismological data are mostly designed for handling instrumentally recorded data. Researchers working on historical seismology are forced to perform their daily job using a general purpose tool and/or coding their own to address their specific tasks. The lack of out-of-the-box tools expressly conceived to deal with historical data leads to a huge amount of time lost in performing tedious task to search for the data and, to manually reformat it in order to jump from one tool to the other, sometimes causing a loss of the original data. This reality is common to all activities related to the study of earthquakes of the past centuries, from the interpretations of past historical sources, to the compilation of earthquake catalogues. A platform able to preserve the historical earthquake data, trace back their source, and able to fulfil many common tasks was very much needed. In the framework of two European projects (NERIES and SHARE) and one global project (Global Earthquake History, GEM), two new data portals were designed and implemented. The European portal "Archive of Historical Earthquakes Data" (AHEAD) and the worldwide "Global Historical Earthquake Archive" (GHEA), are aimed at addressing at least some of the above mentioned issues. The availability of these new portals and their well-defined standards makes it easier than before the development of side tools for archiving, publishing and processing the available historical earthquake data. The AHEAD and GHEA portals, their underlying technologies and the developed side tools are presented.

  11. Dissolution Dominating Calcification Process in Polar Pteropods Close to the Point of Aragonite Undersaturation

    Science.gov (United States)

    Bednaršek, Nina; Tarling, Geraint A.; Bakker, Dorothee C. E.; Fielding, Sophie; Feely, Richard A.

    2014-01-01

    Thecosome pteropods are abundant upper-ocean zooplankton that build aragonite shells. Ocean acidification results in the lowering of aragonite saturation levels in the surface layers, and several incubation studies have shown that rates of calcification in these organisms decrease as a result. This study provides a weight-specific net calcification rate function for thecosome pteropods that includes both rates of dissolution and calcification over a range of plausible future aragonite saturation states (Ωar). We measured gross dissolution in the pteropod Limacina helicina antarctica in the Scotia Sea (Southern Ocean) by incubating living specimens across a range of aragonite saturation states for a maximum of 14 days. Specimens started dissolving almost immediately upon exposure to undersaturated conditions (Ωar∼0.8), losing 1.4% of shell mass per day. The observed rate of gross dissolution was different from that predicted by rate law kinetics of aragonite dissolution, in being higher at Ωar levels slightly above 1 and lower at Ωar levels of between 1 and 0.8. This indicates that shell mass is affected by even transitional levels of saturation, but there is, nevertheless, some partial means of protection for shells when in undersaturated conditions. A function for gross dissolution against Ωar derived from the present observations was compared to a function for gross calcification derived by a different study, and showed that dissolution became the dominating process even at Ωar levels close to 1, with net shell growth ceasing at an Ωar of 1.03. Gross dissolution increasingly dominated net change in shell mass as saturation levels decreased below 1. As well as influencing their viability, such dissolution of pteropod shells in the surface layers will result in slower sinking velocities and decreased carbon and carbonate fluxes to the deep ocean. PMID:25285916

  12. The effect of post-processing treatments on inflection points in current–voltage curves of roll-to-roll processed polymer photovoltaics

    DEFF Research Database (Denmark)

    Lilliedal, Mathilde Raad; Medford, Andrew James; Vesterager Madsen, Morten

    2010-01-01

    Inflection point behaviour is often observed in the current–voltage (IV) curve of polymer solar cells. This phenomenon is examined in the context of flexible roll-to-roll (R2R) processed polymer solar cells in a large series of devices with a layer structure of: PET–ITO–ZnO–P3HT...... characterization of device interfaces was carried out in order to identify possible chemical processes that are related to photo-annealing. A possible mechanism based on ZnO photoconductivity, photooxidation and redistribution of oxygen inside the cell is proposed, and it is anticipated that the findings......:PCBM–PEDOT:PSS–Ag. The devices were manufactured using a combination of slot-die coating and screen printing; they were then encapsulated by lamination using a polymer based barrier material. All manufacturing steps were carried out in ambient air. The freshly prepared devices showed a consistent inflection point in the IV...

  13. On the diffusion process of irradiation-induced point defects in the stress field of a moving dislocation

    International Nuclear Information System (INIS)

    Steinbach, E.

    1987-01-01

    The cellular model of a dislocation is used for an investigation of the time-dependent diffusion process of irradiation-induced point defects interacting with the stress field of a moving dislocation. An analytic solution is given taking into account the elastic interaction due to the first-order size effect and the stress-induced interaction, the kinematic interaction due to the dislocation motion as well as the presence of secondary neutral sinks. The results for the space and time-dependent point defect concentration, represented in terms of Mathieu-Bessel and Mathieu-Hankel functions, emphasize the influence of the parameters which have been taken into consideration. Proceeding from these solutions, formulae for the diffusion flux reaching unit length of the dislocation, which plays an important role with regard to void swelling and irradiation-induced creep, are derived

  14. The signer and the sign: cortical correlates of person identity and language processing from point-light displays.

    Science.gov (United States)

    Campbell, Ruth; Capek, Cheryl M; Gazarian, Karine; MacSweeney, Mairéad; Woll, Bencie; David, Anthony S; McGuire, Philip K; Brammer, Michael J

    2011-09-01

    In this study, the first to explore the cortical correlates of signed language (SL) processing under point-light display conditions, the observer identified either a signer or a lexical sign from a display in which different signers were seen producing a number of different individual signs. Many of the regions activated by point-light under these conditions replicated those previously reported for full-image displays, including regions within the inferior temporal cortex that are specialised for face and body-part identification, although such body parts were invisible in the display. Right frontal regions were also recruited - a pattern not usually seen in full-image SL processing. This activation may reflect the recruitment of information about person identity from the reduced display. A direct comparison of identify-signer and identify-sign conditions showed these tasks relied to a different extent on the posterior inferior regions. Signer identification elicited greater activation than sign identification in (bilateral) inferior temporal gyri (BA 37/19), fusiform gyri (BA 37), middle and posterior portions of the middle temporal gyri (BAs 37 and 19), and superior temporal gyri (BA 22 and 42). Right inferior frontal cortex was a further focus of differential activation (signer>sign). These findings suggest that the neural systems supporting point-light displays for the processing of SL rely on a cortical network including areas of the inferior temporal cortex specialized for face and body identification. While this might be predicted from other studies of whole body point-light actions (Vaina, Solomon, Chowdhury, Sinha, & Belliveau, 2001) it is not predicted from the perspective of spoken language processing, where voice characteristics and speech content recruit distinct cortical regions (Stevens, 2004) in addition to a common network. In this respect, our findings contrast with studies of voice/speech recognition (Von Kriegstein, Kleinschmidt, Sterzer

  15. Modelo de organização de indicadores para operacionalização dos determinantes socioambientais da saúde Model of organization of indicators for operationalizing the social-environmental determinants of health

    Directory of Open Access Journals (Sweden)

    André Sobral

    2010-03-01

    Full Text Available O tema dos determinantes sociais e suas relações com o processo saúde-doença entre diferentes grupos populacionais é de grande relevância para a Saúde Pública e vêm ganhando cada vez mais destaque. Nesse processo, modelos teórico-conceituais vêm sendo adotados para explicar como os determinantes sociais geram iniquidades em saúde, de modo a subsidiar ações voltadas para as "causas das causas" e indicadores relacionados aos diferentes determinantes vêm sendo organizados por meio de metodologias que possibilitem análises integradas. Apesar desses avanços, os problemas ambientais que hoje se constituem em importantes elementos indutores da geração de doenças por meio da degradação dos ecossistemas e das mudanças climáticas têm sido pouco considerados como determinantes ambientais da saúde em conjunto com os sociais. Este artigo tem o objetivo de ampliar as discussões teóricas sobre os determinantes socioambientais da saúde, apresentando, para isso, uma metodologia de organização de indicadores de saúde ambiental denominada Força Motriz-Pressão-Situação-Exposição-Efeito-Ação, a fim de operacionalizar os determinantes sociais da saúde.The theme of social determinants and their relationship to the health-disease process in different population groups is highly relevant to public health and has been attracting increasing attention. In this process, theoretical-conceptual models have been adopted to explain how social determinants generate inequalities in health. Such models aim at supporting measures focusing on 'causes of the causes', while indicators related to different determinants have been organized by means of methodologies that allow integrated analyses. Despite such progress, environmental problems that currently constitute important disease-generating factors through ecosystem degradation and climate changes have received little attention as environmental determinants of health, jointly with social

  16. Neutron-rich isotopes around the r-process 'waiting-point' nuclei 2979Cu50 and 3080Zn50

    International Nuclear Information System (INIS)

    Kratz, K.L.; Gabelmann, H.; Pfeiffer, B.; Woehr, A.

    1991-01-01

    Beta-decay half-lives (T 1/2 ) and delayed-neutron emission probabilities (P n ) of very neutron-rich Cu to As nuclei have been measured, among them the new isotopes 77 Cu 48 , 79 Cu 50 , 81 Zn 51 and 84 Ga 53 . With the T 1/2 and P n -values of now four N≅50 'waiting-point' nuclei known, our hypothesis that the r-process has attained a local β-flow equilibrium around A≅80 is further strengthened. (orig.)

  17. Point processes statistics of stable isotopes: analysing water uptake patterns in a mixed stand of Aleppo pine and Holm oak

    Directory of Open Access Journals (Sweden)

    Carles Comas

    2015-04-01

    Full Text Available Aim of study: Understanding inter- and intra-specific competition for water is crucial in drought-prone environments. However, little is known about the spatial interdependencies for water uptake among individuals in mixed stands. The aim of this work was to compare water uptake patterns during a drought episode in two common Mediterranean tree species, Quercus ilex L. and Pinus halepensis Mill., using the isotope composition of xylem water (δ18O, δ2H as hydrological marker. Area of study: The study was performed in a mixed stand, sampling a total of 33 oaks and 78 pines (plot area= 888 m2. We tested the hypothesis that both species uptake water differentially along the soil profile, thus showing different levels of tree-to-tree interdependency, depending on whether neighbouring trees belong to one species or the other. Material and Methods: We used pair-correlation functions to study intra-specific point-tree configurations and the bivariate pair correlation function to analyse the inter-specific spatial configuration. Moreover, the isotopic composition of xylem water was analysed as a mark point pattern. Main results: Values for Q. ilex (δ18O = –5.3 ± 0.2‰, δ2H = –54.3 ± 0.7‰ were significantly lower than for P. halepensis (δ18O = –1.2 ± 0.2‰, δ2H = –25.1 ± 0.8‰, pointing to a greater contribution of deeper soil layers for water uptake by Q. ilex. Research highlights: Point-process analyses revealed spatial intra-specific dependencies among neighbouring pines, showing neither oak-oak nor oak-pine interactions. This supports niche segregation for water uptake between the two species.

  18. Hierarchical random additive process and logarithmic scaling of generalized high order, two-point correlations in turbulent boundary layer flow

    Science.gov (United States)

    Yang, X. I. A.; Marusic, I.; Meneveau, C.

    2016-06-01

    Townsend [Townsend, The Structure of Turbulent Shear Flow (Cambridge University Press, Cambridge, UK, 1976)] hypothesized that the logarithmic region in high-Reynolds-number wall-bounded flows consists of space-filling, self-similar attached eddies. Invoking this hypothesis, we express streamwise velocity fluctuations in the inertial layer in high-Reynolds-number wall-bounded flows as a hierarchical random additive process (HRAP): uz+=∑i=1Nzai . Here u is the streamwise velocity fluctuation, + indicates normalization in wall units, z is the wall normal distance, and ai's are independently, identically distributed random additives, each of which is associated with an attached eddy in the wall-attached hierarchy. The number of random additives is Nz˜ln(δ /z ) where δ is the boundary layer thickness and ln is natural log. Due to its simplified structure, such a process leads to predictions of the scaling behaviors for various turbulence statistics in the logarithmic layer. Besides reproducing known logarithmic scaling of moments, structure functions, and correlation function [" close="]3/2 uz(x ) uz(x +r ) >, new logarithmic laws in two-point statistics such as uz4(x ) > 1 /2, 1/3, etc. can be derived using the HRAP formalism. Supporting empirical evidence for the logarithmic scaling in such statistics is found from the Melbourne High Reynolds Number Boundary Layer Wind Tunnel measurements. We also show that, at high Reynolds numbers, the above mentioned new logarithmic laws can be derived by assuming the arrival of an attached eddy at a generic point in the flow field to be a Poisson process [Woodcock and Marusic, Phys. Fluids 27, 015104 (2015), 10.1063/1.4905301]. Taken together, the results provide new evidence supporting the essential ingredients of the attached eddy hypothesis to describe streamwise velocity fluctuations of large, momentum transporting eddies in wall-bounded turbulence, while observed deviations suggest the need for further extensions of the

  19. Determinantes y perfiles de la participacion laboral en Colombia en el periodo 2002-2013

    Directory of Open Access Journals (Sweden)

    Nestor Ivan Gonzalez-Quintero

    2015-06-01

    Full Text Available Para establecer los determinantes de la participación laboral en Colombia, sobre una muestra de individuos con representatividad nacional, así como el aporte de cada uno de estos determinantes a la dinámica de la tasa de participación en el periodo 2002-2013, se estiman modelos tipo probit y se establecen perfiles de participación, a partir de las probabilidades estimadas, condicionadas para cuatro grupos de mujeres y hombres en diferentes rangos de edad. Se concluye que alcanzar niveles de educación superior, contar con un ingreso por pensión y la presencia de menores en el hogar son factores importantes para explicar tal dinámica.

  20. Determinantes del acceso a los productos financieros en los hogares colombianos

    Directory of Open Access Journals (Sweden)

    Santiago Rodríguez-Raga

    2016-01-01

    Full Text Available Existe evidencia que establece una asociación positiva entre el acceso a productos financieros, la riqueza y calidad de vida de los hogares, en especial de los hogares pobres. En este ámbito, este estudio busca entender los determinantes del acceso a los diferentes productos financieros en los hogares de Colombia, utilizando un modelo econométrico con base en la información contenida en la Encuesta Longitudinal Colombiana (ELCA de la Universidad de los Andes. Como conclusión se encuentra que los principales determinantes del acceso a productos financieros son el nivel de ingreso o riqueza, la educación y la estabilidad en términos laborales.

  1. Determinantal and worldline quantum Monte Carlo methods for many-body systems

    International Nuclear Information System (INIS)

    Vekic, M.; White, S.R.

    1993-01-01

    We examine three different quantum Monte Carlo methods for studying systems of interacting particles. The determinantal quantum Monte Carlo method is compared to two different worldline simulations. The first worldline method consists of a simulation carried out in the real-space basis, while the second method is implemented using as basis the eigenstates of the Hamiltonian on blocks of the two-dimensional lattice. We look, in particular, at the Hubbard model on a 4x4 lattice with periodic boundary conditions. The block method is superior to the real-space method in terms of the computational cost of the simulation, but shows a much worse negative sign problem. For larger values of U and away from half-filling it is found that the real-space method can provide results at lower temperatures than the determinantal method. We show that the sign problem in the block method can be slightly improved by an appropriate choice of basis

  2. Determinantes de la fusiones y adquisiciones en el sistema financiero colombiano. 1990-2007.

    Directory of Open Access Journals (Sweden)

    Andres Felipe García

    2010-05-01

    Full Text Available Para el caso colombiano se han analizado de manera amplia los efectos de la quiebra y la fusión de las instituciones financieras; sin embargo, no se contaba con un estudio microeconometrico para determinar los determinantes de este tipo de operaciones. Este documento se concentra en determinar cuáles son las variables claves que incentivan la participación de las instituciones financieras en operaciones de integración, mediante la estimación de modelos de duración. Se encuentra que el buen desempeño de las armas reduce la probabilidad de fusión o adquisición de instituciones financieras y que variables macroeconómicas como el crecimiento y la concentración del mercado son  determinantes de estas.

  3. DETERMINANTES DE LA INFORMALIDAD LABORAL: UN ANÁLISIS PARA COLOMBIA

    Directory of Open Access Journals (Sweden)

    Raúl Quejada Pérez

    2014-01-01

    Full Text Available La informalidad representa una alternativa de fuente de ingresos ante la falta de oportunidades que tienen las personas de obtener un empleo en el sector formal. Este artículo muestra los resultados de una revisión sobre la informalidad y sus determinantes, y destaca que el desempleo es la principal causa de esta situación, además de factores sociodemográficos, tales como el nivel educativo y el género. Por su parte, en el ámbito económico se encuentran factores asociados a la globalización, desarrollo industrial, ciclo económico y tipo de cambio real, mientras que en el aspecto institucional la regulación del mercado de trabajo son los elementos determinantes de la informalidad y sus correspondientes consecuencias.

  4. Determinantes de la informalidad laboral: Un análisis para Colombia

    Directory of Open Access Journals (Sweden)

    Raúl Quejada Pérez

    2013-08-01

    Full Text Available La informalidad representa una alternativa de fuente de ingresos ante la falta de oportunidades que tienen las personas de obtener un empleo en el sector formal. Este artículo muestra los resultados de una revisión sobre la informalidad y sus determinantes, y destaca que el desempleo es la principal causa de esta situación, además de factores sociodemográficos, tales como el nivel educativo y el género. Por su parte, en el ámbito económico se encuentran factores asociados a la globalización, desarrollo industrial, ciclo económico y tipo de cambio real, mientras que en el aspecto institucional la regulación del mercado de trabajo son los elementos determinantes de la informalidad y sus correspondientes consecuencias.

  5. Factores determinantes del nivel de compromiso medioambiental voluntario adquirido por los hoteles cotizados europeos

    OpenAIRE

    Patricia Milanés Montero; Esteban Pérez Calderón; Francisco Javier Ortega Rossell

    2012-01-01

    Ante las importantes presiones que la actividad hotelera ejerce sobre el medioambiente, la ausencia de regulación de las actuaciones responsables y la escasez de investigaciones al respecto aparece la imperiosa necesidad de aportar luz en este sentido. Por ello, en este trabajo se analiza el compromiso medioambiental corporativo de los hoteles cotizados europeos; se utiliza como metodología el análisis de contenidos y se detectan los factores determinantes de las actuaciones responsables con ...

  6. Two-dimensional gauge dynamics and the topology of singular determinantal varieties

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Kenny [Department of Applied Mathematics and Theoretical Physics,Centre for Mathematical Sciences, University of Cambridge,Cambridge, CB3 0WA (United Kingdom)

    2017-03-27

    We record an observation about the Witten indices in two families of gauged linear sigma models: the U(2) model for linear sections of Grassmannians, and the U(1) model for quadric complete intersections. We describe how the Witten indices are related to the Euler characteristics of the singular skew-symmetric or symmetric determinantal varieties featuring in the analysis of their opposite phases, and we discuss the extent to which these relationships can be reconciled with standard Born-Oppenheimer arguments.

  7. Estudio de determinantes sociales y estado de salud de la población

    Directory of Open Access Journals (Sweden)

    Hilda María Delgado Acosta

    2013-12-01

    Full Text Available Fundamento: el estudio de las determinantes sociales de la salud constituye una herramienta esencial para modificar el estado de salud de las poblaciones. Objetivo: describir la expresión de algunas determinantes de la salud y su relación con indicadores de salud en el Área I del municipio Cienfuegos durante el año 2011. Métodos: se realizó un estudio descriptivo sobre la contribución de algunas determinantes sociales al estado de salud de la población del Área I del municipio Cienfuegos durante el año 2011. Para ello se tuvieron en cuenta indicadores demográficos, sociales, medioambientales, de estilos de vida y de la organización de los servicios de salud. Resultados: el Área I resultó ser desfavorecida en varias de las dimensiones estudiadas como: medio ambiente, y en la organización de los servicios de salud, con inestabilidad en el cumplimiento de consultas y terrenos e incremento de los casos vistos en los Servicios de Urgencia, se observó elevado porcentaje en la exposición a factores de riesgo cardiovascular con repercusión en la mortalidad dentro de las primeras causas de muerte sin dejar de destacar el incremento que hubo en la incidencia de enfermedades transmisibles como: tuberculosis, enfermedades diarreicas e infecciones de transmisión sexual. Conclusiones: existen evidencias que permiten encauzar acciones para modificar el estado de salud de la población del Área I del municipio Cienfuegos desde la expresión de sus determinantes, con énfasis en la organización de los servicios de salud.

  8. Crisis económica en España y sus factores determinantes

    OpenAIRE

    Monte Aznar, Javier del

    2016-01-01

    El trabajo trata de analizar las causas o factores determinantes de la crisis en España desde el punto de vista de la teoría Keynesiana, analizando la evolución de factores como la inversión, el consumo y el trabajo, desembocando en medidas que se pueden tomar para la salida de la crisis. Grado en Administración y Dirección de Empresas

  9. Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales

    KAUST Repository

    Yuan, Yuan; Bachl, Fabian E.; Lindgren, Finn; Borchers, David L.; Illian, Janine B.; Buckland, Stephen T.; Rue, Haavard; Gerrodette, Tim

    2017-01-01

    Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density can be estimated using these methods. Estimates are usually obtained at survey stratum level. For an endangered species such as the blue whale, it is desirable to estimate density and abundance at a finer spatial scale than stratum. Temporal variation in the spatial structure is also important. We formulate the process generating distance sampling data as a thinned spatial point process and propose model-based inference using a spatial log-Gaussian Cox process. The method adopts a flexible stochastic partial differential equation (SPDE) approach to model spatial structure in density that is not accounted for by explanatory variables, and integrated nested Laplace approximation (INLA) for Bayesian inference. It allows simultaneous fitting of detection and density models and permits prediction of density at an arbitrarily fine scale. We estimate blue whale density in the Eastern Tropical Pacific Ocean from thirteen shipboard surveys conducted over 22 years. We find that higher blue whale density is associated with colder sea surface temperatures in space, and although there is some positive association between density and mean annual temperature, our estimates are consistent with no trend in density across years. Our analysis also indicates that there is substantial spatially structured variation in density that is not explained by available covariates.

  10. Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales

    KAUST Repository

    Yuan, Yuan

    2017-12-28

    Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density can be estimated using these methods. Estimates are usually obtained at survey stratum level. For an endangered species such as the blue whale, it is desirable to estimate density and abundance at a finer spatial scale than stratum. Temporal variation in the spatial structure is also important. We formulate the process generating distance sampling data as a thinned spatial point process and propose model-based inference using a spatial log-Gaussian Cox process. The method adopts a flexible stochastic partial differential equation (SPDE) approach to model spatial structure in density that is not accounted for by explanatory variables, and integrated nested Laplace approximation (INLA) for Bayesian inference. It allows simultaneous fitting of detection and density models and permits prediction of density at an arbitrarily fine scale. We estimate blue whale density in the Eastern Tropical Pacific Ocean from thirteen shipboard surveys conducted over 22 years. We find that higher blue whale density is associated with colder sea surface temperatures in space, and although there is some positive association between density and mean annual temperature, our estimates are consistent with no trend in density across years. Our analysis also indicates that there is substantial spatially structured variation in density that is not explained by available covariates.

  11. Decoding the non-stationary neuron spike trains by dual Monte Carlo point process estimation in motor Brain Machine Interfaces.

    Science.gov (United States)

    Liao, Yuxi; Li, Hongbao; Zhang, Qiaosheng; Fan, Gong; Wang, Yiwen; Zheng, Xiaoxiang

    2014-01-01

    Decoding algorithm in motor Brain Machine Interfaces translates the neural signals to movement parameters. They usually assume the connection between the neural firings and movements to be stationary, which is not true according to the recent studies that observe the time-varying neuron tuning property. This property results from the neural plasticity and motor learning etc., which leads to the degeneration of the decoding performance when the model is fixed. To track the non-stationary neuron tuning during decoding, we propose a dual model approach based on Monte Carlo point process filtering method that enables the estimation also on the dynamic tuning parameters. When applied on both simulated neural signal and in vivo BMI data, the proposed adaptive method performs better than the one with static tuning parameters, which raises a promising way to design a long-term-performing model for Brain Machine Interfaces decoder.

  12. Determinantes biopsicossociais que predizem qualidade de vida em pessoas que vivem com HIV/AIDS

    Directory of Open Access Journals (Sweden)

    Bruno Medeiros

    2013-12-01

    Full Text Available O advento da terapia antirretroviral trouxe a necessidade de se compreender os determinantes psicossociais envolvidos na avaliação de qualidade de vida em pessoas que vivem com HIV/AIDS. O objetivo desse estudo é investigar os determinantes psicossociais e clínicos envolvidos na avaliação de qualidade de vida nesse grupo social. Esta pesquisa envolveu 90 pessoas vivendo com HIV/AIDS (média de idade de 33,7 anos, DP = 6,6. Um questionário sócio-demográfico e clínico e o WHOQOL-BREF constituíram os principais métodos. Análises descritivas, comparações entre médias de grupos-critério e análise de regressão foram utilizadas. Os resultados demonstram melhor qualidade de vida entre os que estavam satisfeitos com os serviços de saúde do hospital, bem como os principais determinantes para a avaliação de qualidade de vida são a dimensão psicológica, contagens de células CD4 e a dimensão ambiental. Essa pesquisa sugere a elaboração de políticas públicas de saúde em HIV/AIDS que englobem os fatores psicossociais.

  13. Influência dos determinantes do envelhecimento ativo entre idosos mais idosos

    Directory of Open Access Journals (Sweden)

    Rosimeri Geremias Farias

    2012-01-01

    Full Text Available Estudio cuantitativo, transversal, exploratorio, descriptivo, cuyo objetivo fue averiguar el envejecimiento activo, según sus determinantes, entre los ancianos más viejos en un municipio del interior de Santa Catarina. La obtención de los datos se realizó entre Julio y Agosto del 2009, através de entrevistas con 87 ancianos con 80 años o más, de ambos sexos. Se utilizó check-list elaborada de los determinantes del envejecimiento activo. Hicieron análisis descriptivos, medidas descriptivas de centralidad y dispersión. Los resultados mostraron una paridad de géneros, que las personas eran, mayormente, de raza blanca, católicos, con bajo salario y escolaridad. Aun estando jubilados, el 60,92% continúa ejerciendo actividades laborales; 70,11% posee casa propia; 48,28% frecuenta ambientes colectivos; 81,61% está satisfecho con su vida y 48,28% no depende de cuidador. Se concluye que aunque no alcanzaron todos los determinantes del envejecimiento activo, estos ancianos mantienen su independencia y autonomia, garantizando su cualidad de vida.

  14. Factores determinantes de la contaminación ambiental y del uso de los recursos naturales

    Directory of Open Access Journals (Sweden)

    Klaus Georg Binder

    2002-10-01

    Full Text Available Dentro de los factores determinantes de la utilización contaminante del medio ambiente y del uso de los recursos naturales encontramos: el crecimiento demográfico, el desarrollo económico (crecimiento económico, cambio de la estructura económica, progreso técnico, etc. y la concentración espacial de la población y su actividad económica. A causa de la interdependencia entre los factores determinantes de la utilización del medio ambiente, no se puede decir que el crecimiento económico en los países en desarrollo siempre aumente el uso de los recursos naturales y tenga un impacto negativo sobre la calidad del medio ambiente. La afirmación según la cual todo crecimiento económico implica impactos negativos sobre el medio ambiente, se basa en supuestos poco realistas. La magnitud de la economía es solamente uno de los factores que determinan la utilización del medio ambiente. La pregunta decisiva es si los factores determinantes que, tendencialmente, causan una disminución de la utilización del medio ambiente por unidad del producto interno bruto, puedan compensar con creces los impactos negativos del crecimiento económico.

  15. DETERMINANTES DO P/B, SETOR REGULADO E ESTRATÉGIAS DE INVESTIMENTO

    Directory of Open Access Journals (Sweden)

    Ricardo Goulart Serra

    2016-03-01

    Full Text Available Observou-se uma lacuna de estudos em finanças que analise os determinantes do Price to Book (P/B para o período mais recente. Por meio de uma análise de painel, para 168 empresas com ações listadas na BMF&Bovespa e pelos últimos 40 trimestres, identificou-se os determinantes: (i retorno (relação positiva, (ii crescimento histórico (relação positiva, (iii custo de capital, medido pelo beta e alavancagem (ambos com relação negativa e (iv tamanho (positiva além de um determinante não usual: (v pertencer a um setor regulado (negativa, o que contribui com estudos sobre setores regulados. O fato das empresas pertencentes a setores regulados terem menor P/B pode ser um bom ou um mau sinal. Além disso, observou-se, analisando o Índice de Sharpe, a superioridade da estratégia de investimento em empresas com baixo P/B. Estratégias com outras variáveis também foram testadas, entre elas: tamanho, beta e retorno, de forma a contribuir com as pesquisas sobre o tema.

  16. Determinantes sociais da saude e o Programa Saude da Familia no municipio de Sao Paulo

    Directory of Open Access Journals (Sweden)

    Tatiana Pluciennik Dowbor

    2013-08-01

    Full Text Available OBJETIVO Analisar a situação do trabalho com determinantes sociais da saúde no âmbito do Programa Saúde da Família. MÉTODOS Estudo de caso com métodos mistos de pesquisa, ancorados em estratégia sequencial explanatória, com 171 gerentes das unidades do Programa Saúde da Família em São Paulo, SP, em 2005/2006. Questionários autopreenchíveis foram aplicados. Entrevistas semiestruturadas e grupos focais foram realizados com amostra intencional de profissionais envolvidos no trabalho com determinantes sociais da saúde. Os dados quantitativos foram analisados por análise descritiva, análise de correspondência múltipla, análise de agrupamento e testes de correlação entre variáveis. Os dados qualitativos foram apurados por análise de conteúdo e a criação de categorias temáticas. RESULTADOS Apesar da concentração de atividades direcionadas ao cuidado com a doença, o Programa Saúde da Família realizou atividades relacionadas à determinação social da saúde, contemplando todas as formas de abordagem da promoção da saúde (biológico, comportamental, psicológico, social e estrutural e os principais determinantes sociais da saúde descritos na literatura. Houve diferença significativa quanto à abrangência dos determinantes trabalhados nas unidades em relação às diferentes regiões do município. Constatou-se fragilidade das iniciativas e a sua desconexão com a estrutura programática do Programa Saúde da Família. CONCLUSÕES A quantidade e variedade de atividades com determinantes sociais da saúde realizadas no Programa Saúde da Família mostram potencial para trabalhar a determinação social da saúde. Mas a fluidez de objetivo e o caráter extraordinário das atividades descritas questionam sua sustentabilidade como parte integral da atual estrutura organizacional do programa.

  17. Investigation of the s-process branch-point nucleus {sup 86}Rb at HIγS

    Energy Technology Data Exchange (ETDEWEB)

    Erbacher, Philipp; Glorius, Jan; Reifarth, Rene; Sonnabend, Kerstin [Goethe Universitaet Frankfurt am Main (Germany); Isaak, Johann; Loeher, Bastian; Savran, Deniz [GSI Helmholzzentrum fuer Schwerionenforschung (Germany); Tornow, Werner [Duke University (United States)

    2016-07-01

    The branch-point nucleus {sup 86}Rb determines the isotopic abundance ratio {sup 86}Sr/{sup 87}Sr in s-process nucleosynthesis. Thus, stellar parameters such as temperature and neutron density and their evolution in time as simulated by modern s-process network calculations can be constrained by a comparison of the calculated isotopic ratio with the one observed in SiC meteoritic grains. To this end, the radiative neutron-capture cross section of the unstable isotope {sup 86}Rb has to be known with sufficient accuracy. Since the short half-life of {sup 86}Rb prohibits the direct measurement, the nuclear-physics input to a calculation of the cross section has to be measured. For this reason, the γ-ray strength function of {sup 87}Rb was measured using the γ{sup 3} setup at the High Intensity γ-ray Source facility at TUNL in Durham, USA. First experimental results are presented.

  18. Coupling aerosol-cloud-radiative processes in the WRF-Chem model: Investigating the radiative impact of elevated point sources

    Directory of Open Access Journals (Sweden)

    E. G. Chapman

    2009-02-01

    Full Text Available The local and regional influence of elevated point sources on summertime aerosol forcing and cloud-aerosol interactions in northeastern North America was investigated using the WRF-Chem community model. The direct effects of aerosols on incoming solar radiation were simulated using existing modules to relate aerosol sizes and chemical composition to aerosol optical properties. Indirect effects were simulated by adding a prognostic treatment of cloud droplet number and adding modules that activate aerosol particles to form cloud droplets, simulate aqueous-phase chemistry, and tie a two-moment treatment of cloud water (cloud water mass and cloud droplet number to precipitation and an existing radiation scheme. Fully interactive feedbacks thus were created within the modified model, with aerosols affecting cloud droplet number and cloud radiative properties, and clouds altering aerosol size and composition via aqueous processes, wet scavenging, and gas-phase-related photolytic processes. Comparisons of a baseline simulation with observations show that the model captured the general temporal cycle of aerosol optical depths (AODs and produced clouds of comparable thickness to observations at approximately the proper times and places. The model overpredicted SO2 mixing ratios and PM2.5 mass, but reproduced the range of observed SO2 to sulfate aerosol ratios, suggesting that atmospheric oxidation processes leading to aerosol sulfate formation are captured in the model. The baseline simulation was compared to a sensitivity simulation in which all emissions at model levels above the surface layer were set to zero, thus removing stack emissions. Instantaneous, site-specific differences for aerosol and cloud related properties between the two simulations could be quite large, as removing above-surface emission sources influenced when and where clouds formed within the modeling domain. When summed spatially over the finest

  19. Point process-based modeling of multiple debris flow landslides using INLA: an application to the 2009 Messina disaster

    KAUST Repository

    Lombardo, Luigi

    2018-02-13

    We develop a stochastic modeling approach based on spatial point processes of log-Gaussian Cox type for a collection of around 5000 landslide events provoked by a precipitation trigger in Sicily, Italy. Through the embedding into a hierarchical Bayesian estimation framework, we can use the integrated nested Laplace approximation methodology to make inference and obtain the posterior estimates of spatially distributed covariate and random effects. Several mapping units are useful to partition a given study area in landslide prediction studies. These units hierarchically subdivide the geographic space from the highest grid-based resolution to the stronger morphodynamic-oriented slope units. Here we integrate both mapping units into a single hierarchical model, by treating the landslide triggering locations as a random point pattern. This approach diverges fundamentally from the unanimously used presence–absence structure for areal units since we focus on modeling the expected landslide count jointly within the two mapping units. Predicting this landslide intensity provides more detailed and complete information as compared to the classically used susceptibility mapping approach based on relative probabilities. To illustrate the model’s versatility, we compute absolute probability maps of landslide occurrences and check their predictive power over space. While the landslide community typically produces spatial predictive models for landslides only in the sense that covariates are spatially distributed, no actual spatial dependence has been explicitly integrated so far. Our novel approach features a spatial latent effect defined at the slope unit level, allowing us to assess the spatial influence that remains unexplained by the covariates in the model. For rainfall-induced landslides in regions where the raingauge network is not sufficient to capture the spatial distribution of the triggering precipitation event, this latent effect provides valuable imaging support

  20. A geometric stochastic approach based on marked point processes for road mark detection from high resolution aerial images

    Science.gov (United States)

    Tournaire, O.; Paparoditis, N.

    Road detection has been a topic of great interest in the photogrammetric and remote sensing communities since the end of the 70s. Many approaches dealing with various sensor resolutions, the nature of the scene or the wished accuracy of the extracted objects have been presented. This topic remains challenging today as the need for accurate and up-to-date data is becoming more and more important. Based on this context, we will study in this paper the road network from a particular point of view, focusing on road marks, and in particular dashed lines. Indeed, they are very useful clues, for evidence of a road, but also for tasks of a higher level. For instance, they can be used to enhance quality and to improve road databases. It is also possible to delineate the different circulation lanes, their width and functionality (speed limit, special lanes for buses or bicycles...). In this paper, we propose a new robust and accurate top-down approach for dashed line detection based on stochastic geometry. Our approach is automatic in the sense that no intervention from a human operator is necessary to initialise the algorithm or to track errors during the process. The core of our approach relies on defining geometric, radiometric and relational models for dashed lines objects. The model also has to deal with the interactions between the different objects making up a line, meaning that it introduces external knowledge taken from specifications. Our strategy is based on a stochastic method, and in particular marked point processes. Our goal is to find the objects configuration minimising an energy function made-up of a data attachment term measuring the consistency of the image with respect to the objects and a regularising term managing the relationship between neighbouring objects. To sample the energy function, we use Green algorithm's; coupled with a simulated annealing to find its minimum. Results from aerial images at various resolutions are presented showing that our

  1. Adaptation to Elastic Loads and BMI Robot Controls During Rat Locomotion examined with Point-Process GLMs.

    Directory of Open Access Journals (Sweden)

    Weiguo eSong

    2015-04-01

    Full Text Available Currently little is known about how a mechanically coupled BMI system’s actions are integrated into ongoing body dynamics. We tested a locomotor task augmented with a BMI system driving a robot mechanically interacting with a rat under three conditions: control locomotion (BL, ‘simple elastic load’ (E and ‘BMI with elastic load’ (BMI/E. The effect of the BMI was to allow compensation of the elastic load as a function of the neural drive. Neurons recorded here were close to one another in cortex, all within a 200 micron diameter horizontal distance of one another. The interactions of these close assemblies of neurons may differ from those among neurons at longer distances in BMI tasks and thus are important to explore. A point process generalized linear model (GLM, was used to examine connectivity at two different binning timescales (1ms vs. 10ms. We used GLM models to fit non-Poisson neural dynamics solely using other neurons’ prior neural activity as covariates. Models at different timescales were compared based on Kolmogorov-Smirnov (KS goodness-of-fit and parsimony. About 15% of cells with non-Poisson firing were well fitted with the neuron-to-neuron models alone. More such cells were fitted at the 1ms binning than 10ms. Positive connection parameters (‘excitation’ ~70% exceeded negative parameters (‘inhibition’ ~30%. Significant connectivity changes in the GLM determined networks of well-fitted neurons occurred between the conditions. However, a common core of connections comprising at least ~15% of connections persisted between any two of the three conditions. Significantly almost twice as many connections were in common between the two load conditions (~27%, compared to between either load condition and the baseline. This local point process GLM identified neural correlation structure and the changes seen across task conditions in the rats in this neural subset may be intrinsic to cortex or due to feedback and input

  2. Determinantes sociales de la salud y discapacidad: caso Santiago de Cali / Social determinants of health and disability: the Santiago de Cali case

    Directory of Open Access Journals (Sweden)

    Consuelo Vélez A

    2013-08-01

    Full Text Available Objetivo: establecer la relación entre los determinantes sociales de la salud y la discapacidad en Santiago de Cali. Metodología: estudio descriptivo correlacional. Se incluyeron para el análisis 38.071 personas registradas en la base de datos del Dane (Cali; la información se procesó en SPSS 19.0: determinantes estructurales, género, edad, nivel educativo, raza, zona de residencia, estrato y determinantes intermedios como trabajo y vivienda; se realizó análisis univariado y bivariado empleando la prueba de x2 . Resultados: el 52% de las personas pertenecía al género femenino; el promedio de la edad fue de 48 años +/– 24,1 años y la raza predominante, la mestiza. El 28% de las personas registradas no tenía ningún nivel de estudio; un 76% de las personas pertenecen a estratos 1 y 2. El 100% tienen al menos una deficiencia y una discapacidad y el 25% presentan restricción en la participación. El género femenino presenta menos restricción en la participación, comparado con el masculino (71,2% y 66,8% respectivamente. Se encontró asociación entre los determinantes sociales estructurales e intermedios y la restricción en la participación p < 0,05. Conclusiones: existe interacción de los determinantes sociales de la salud, como género, educación, empleo, barreras arquitectónicas y servicios de salud, entre otros, con la restricción en la participación Objective: to establish the relationship between the social determinants of health and disability in Santiago de Cali. Methodology: a correlational descriptive study. The analysis included a total of 38,071 people who had been registered in the dane database (Cali, and the data was processed using the spss 19.0 software. Structural Determinants: gender, age, education level, race, area of residence, and intermediate determinants such as job and housing information. In addition, univariate and bivariate analyses were conducted using the x2 test. Results: of the participants

  3. Comparison of second-generation processes for the conversion of sugarcane bagasse to liquid biofuels in terms of energy efficiency, pinch point analysis and Life Cycle Analysis

    International Nuclear Information System (INIS)

    Petersen, A.M.; Melamu, Rethabi; Knoetze, J.H.; Görgens, J.F.

    2015-01-01

    Highlights: • Process evaluation of thermochemical and biological routes for bagasse to fuels. • Pinch point analysis increases overall efficiencies by reducing utility consumption. • Advanced biological route increased efficiency and local environmental impacts. • Thermochemical routes have the highest efficiencies and low life cycle impacts. - Abstract: Three alternative processes for the production of liquid transportation biofuels from sugar cane bagasse were compared, on the perspective of energy efficiencies using process modelling, Process Environmental Assessments and Life Cycle Assessment. Bio-ethanol via two biological processes was considered, i.e. Separate Hydrolysis and Fermentation (Process 1) and Simultaneous Saccharification and Fermentation (Process 2), in comparison to Gasification and Fischer Tropsch synthesis for the production of synthetic fuels (Process 3). The energy efficiency of each process scenario was maximised by pinch point analysis for heat integration. The more advanced bio-ethanol process was Process 2 and it had a higher energy efficiency at 42.3%. Heat integration was critical for the Process 3, whereby the energy efficiency was increased from 51.6% to 55.7%. For both the Process Environmental and Life Cycle Assessment, Process 3 had the least potential for detrimental environmental impacts, due to its relatively high energy efficiency. Process 2 had the greatest Process Environmental Impact due to the intensive use of processing chemicals. Regarding the Life Cycle Assessments, Process 1 was the most severe due to its low energy efficiency

  4. ¿Es el Tamaño de una Entidad de Crédito Factor Determinante de los Resultados Derivados de su Gestión?

    Directory of Open Access Journals (Sweden)

    A. Javier Pérez García

    1999-12-01

    Full Text Available El objeto del trabajo se concreta en contrastar si la dimensión de una entidad de crédito es o no una variable determinante de la gestión empresarial. Para ello efectuamos un análisis estático transversal referido al ejercicio 1995, efectuando un análisis financiero riguroso e individualizado para 93, crédito españolas. Una vez identificados los factores determinantes de los resultados de la gestión empresarial, pasamos a estudiar el grado de relación entre las variables explicativas y explicadas, para terminar estableciendo una tipología de entidades en función de sus modelos de gestión aplicando diversas técnicas de análisis multivariable. El trabajo pone de manifiesto que el tamaño de una entidad de crédito no es un factor determinante de los resultados de la gestión. Asimismo detectamos la existencia de cinco modelos de gestión di firmándose que, desde un punto de vista técnico, una dimensión mayor no garantiza mejore derivados de la gestión de la entidad. No obstante, no podemos obviar que existen razones, e ponente político importante, que anteponen el crecimiento al logro de una rentabilidad ad dimensión. The objective of the article is to contrast if the size of a financial entity is a determining variable, in its performance measurement. To demonstrate this, we have carried out a static cross analysis, in relation exercise for 1995, performing a thorough and individual financial analysis on 93 Spanish financial entities. Once the determining factors of the performance measurement have been identified, we go the level of relation between variables in order to determine a class of entities in terms of their performance measurement applying multivariable analysis techniques. The study draws attention to the fact that the size of the financial entities is not a determining performance measurement. We detect the existence of five different performance models, confirming from a technical point of view, a greater

  5. Hygienic-sanitary working practices and implementation of a Hazard Analysis and Critical Control Point (HACCP plan in lobster processing industries

    Directory of Open Access Journals (Sweden)

    Cristina Farias da Fonseca

    2013-03-01

    Full Text Available This study aimed to verify the hygienic-sanitary working practices and to create and implement a Hazard Analysis Critical Control Point (HACCP in two lobster processing industries in Pernambuco State, Brazil. The industries studied process frozen whole lobsters, frozen whole cooked lobsters, and frozen lobster tails for exportation. The application of the hygienic-sanitary checklist in the industries analyzed achieved conformity rates over 96% to the aspects evaluated. The use of the Hazard Analysis Critical Control Point (HACCP plan resulted in the detection of two critical control points (CCPs including the receiving and classification steps in the processing of frozen lobster and frozen lobster tails, and an additional critical control point (CCP was detected during the cooking step of processing of the whole frozen cooked lobster. The proper implementation of the Hazard Analysis Critical Control Point (HACCP plan in the lobster processing industries studied proved to be the safest and most cost-effective method to monitor each critical control point (CCP hazards.

  6. Design and development of cell queuing, processing, and scheduling modules for the iPOINT input-buffered ATM testbed

    Science.gov (United States)

    Duan, Haoran

    1997-12-01

    This dissertation presents the concepts, principles, performance, and implementation of input queuing and cell-scheduling modules for the Illinois Pulsar-based Optical INTerconnect (iPOINT) input-buffered Asynchronous Transfer Mode (ATM) testbed. Input queuing (IQ) ATM switches are well suited to meet the requirements of current and future ultra-broadband ATM networks. The IQ structure imposes minimum memory bandwidth requirements for cell buffering, tolerates bursty traffic, and utilizes memory efficiently for multicast traffic. The lack of efficient cell queuing and scheduling solutions has been a major barrier to build high-performance, scalable IQ-based ATM switches. This dissertation proposes a new Three-Dimensional Queue (3DQ) and a novel Matrix Unit Cell Scheduler (MUCS) to remove this barrier. 3DQ uses a linked-list architecture based on Synchronous Random Access Memory (SRAM) to combine the individual advantages of per-virtual-circuit (per-VC) queuing, priority queuing, and N-destination queuing. It avoids Head of Line (HOL) blocking and provides per-VC Quality of Service (QoS) enforcement mechanisms. Computer simulation results verify the QoS capabilities of 3DQ. For multicast traffic, 3DQ provides efficient usage of cell buffering memory by storing multicast cells only once. Further, the multicast mechanism of 3DQ prevents a congested destination port from blocking other less- loaded ports. The 3DQ principle has been prototyped in the Illinois Input Queue (iiQueue) module. Using Field Programmable Gate Array (FPGA) devices, SRAM modules, and integrated on a Printed Circuit Board (PCB), iiQueue can process incoming traffic at 800 Mb/s. Using faster circuit technology, the same design is expected to operate at the OC-48 rate (2.5 Gb/s). MUCS resolves the output contention by evaluating the weight index of each candidate and selecting the heaviest. It achieves near-optimal scheduling and has a very short response time. The algorithm originates from a

  7. Quantifying the effect of sea level rise and flood defence - a point process perspective on coastal flood damage

    Science.gov (United States)

    Boettle, M.; Rybski, D.; Kropp, J. P.

    2016-02-01

    In contrast to recent advances in projecting sea levels, estimations about the economic impact of sea level rise are vague. Nonetheless, they are of great importance for policy making with regard to adaptation and greenhouse-gas mitigation. Since the damage is mainly caused by extreme events, we propose a stochastic framework to estimate the monetary losses from coastal floods in a confined region. For this purpose, we follow a Peak-over-Threshold approach employing a Poisson point process and the Generalised Pareto Distribution. By considering the effect of sea level rise as well as potential adaptation scenarios on the involved parameters, we are able to study the development of the annual damage. An application to the city of Copenhagen shows that a doubling of losses can be expected from a mean sea level increase of only 11 cm. In general, we find that for varying parameters the expected losses can be well approximated by one of three analytical expressions depending on the extreme value parameters. These findings reveal the complex interplay of the involved parameters and allow conclusions of fundamental relevance. For instance, we show that the damage typically increases faster than the sea level rise itself. This in turn can be of great importance for the assessment of sea level rise impacts on the global scale. Our results are accompanied by an assessment of uncertainty, which reflects the stochastic nature of extreme events. While the absolute value of uncertainty about the flood damage increases with rising mean sea levels, we find that it decreases in relation to the expected damage.

  8. Características del conocimiento transferido como determinantes del rendimiento de los sistemas de franquicia

    OpenAIRE

    Beatriz Minguela Rata; María Concepción Rodríguez Benavides; José Ignacio López Sánchez

    2009-01-01

    En este trabajo se pretende analizar la influencia de la naturaleza tácita y el valor del conocimiento (dos características del conocimiento determinantes de la facilidad con la que se puede transferir el mismo) en el rendimiento de los sistemas de franquicia. Se ha llevado a cabo un análisis de regresión lineal sobre una muestra de establecimientos franquiciados en diferentes cadenas de franquicia y sectores de actividad que operan en España, midiendo el rendimiento tanto de manera objetiva ...

  9. Determinantes sociales de la salud de la OMS en mujeres mexicanas con el virus de papiloma

    OpenAIRE

    Soltero-Rivera, Silvia Guadalupe; Cerda-Flores, Ricardo Martin; Cárdenas-Villarreal, Velia Margarita; Guevara-Valtier, Milton Carlos; Paz Morales, María de los Angeles; Patton-Leal, Adrián Carlos; Ramírez-García, Esther Justina

    2016-01-01

    Uno de los temas centrales de la OMS es el análisis de los problemas de salud mediante el modelo de Determinantes Sociales de la Salud (DSS: inadecuadas condiciones económicas, ambientales y de alimentación). El sistema sanitario de la OMS ha asociado algunas enfermedades tal como el Virus de Papiloma Humano (VPH) con losDSS. Desde el punto de vista de investigación cuantitativa, los DSS reportados por la OMS son: 1) edad de inicio de la actividad sexual, 2) múltiples compañeros sexuales, 3) ...

  10. Determinantes del acceso a los productos financieros en los hogares colombianos

    OpenAIRE

    Santiago Rodríguez-Raga; Félix Francisco Riaño Rodríguez

    2016-01-01

    Existe evidencia que establece una asociación positiva entre el acceso a productos financieros, la riqueza y calidad de vida de los hogares, en especial de los hogares pobres. En este ámbito, este estudio busca entender los determinantes del acceso a los diferentes productos financieros en los hogares de Colombia, utilizando un modelo econométrico con base en la información contenida en la Encuesta Longitudinal Colombiana (ELCA) de la Universidad de los Andes. Como conclusión se encuentra que...

  11. Determinantes del ingreso de los hogares y de su gasto corriente

    OpenAIRE

    Muñoz Conde, Manuel

    2008-01-01

    Este ensayo de investigación empírica analiza los determinantes del ingreso y del gasto en los hogares colombianos. Utilizando un modelo del ciclo de vida con datos de la encuesta de hogares de 1994 y 1995, muestra que el comportamiento del ingreso está afectado principalmente por las características demográficas del hogar y los rasgos socio ocupacionales de sus miembros. El comportamiento del gasto está determinado ante todo por el ingreso y, en menor medida, por las características sociales...

  12. Contabilidad: comentarios sobre el discurso científico y los determinantes morales

    Directory of Open Access Journals (Sweden)

    Mauricio Gómez Villegas

    2003-11-01

    Full Text Available En este documento se discute el carácter científico de la corriente principal de la contabilidad. Desde un enfoque socioepistemológico, se analizan los limitantes y cuestionamientos a la perspectiva positivista de la ciencia y a su aplicación en la perspectiva predominante en la contabilidad sajona. Se plantean aportes desde la escuela sociológica-organizacional de corte europeo. En especial se llama la atención sobre la necesidad del estudio de los determinantes morales que reproduce la contabilidad en el orden moral vigente.

  13. Determinantes del consumo de tabaco en adolescentes : diferencias de género

    OpenAIRE

    Pellico López, María Amada

    2015-01-01

    El tabaco es la principal causa de muerte actualmente. La feminización del hábito tabáquico actual ocasionará en el futuro un aumento de la carga de enfermedad y muerte atribuible al tabaco en mujeres. La presente monografía pretende describir la situación entre nuestros adolescentes, que determinantes influyen en que varones y mujeres adolescentes consuman tabaco y cómo intervenir de forma efectiva para prevenirlo. La diferencia de género en consumo de tabaco tiende a desaparecer y las mujer...

  14. Los determinantes de la salud percibida en España

    OpenAIRE

    Girón Daviña , Pedro

    2010-01-01

    Esta tesis plantea como hipótesis de trabajo que la salud percibida en España es un indicador multidimensional e integral de la salud que está vinculado a los factores que afectan a la salud objetiva, lo que le convierte en un indicador complementario a otras medidas de salud de los profesionales sanitarios. El objetivo de esta tesis es analizar y modelar los distintos determinantes de la salud percibida de los españoles de 16 o más años de edad. Para ello se utiliza la ENS del año 2006, ...

  15. Determinantes del acceso al internet: Evidencia de los hogares del Ecuador

    OpenAIRE

    Botello-Peñaloza, Héctor Alberto

    2015-01-01

    El objetivo del artículo se centra en investigar los determinantes del uso de Iinternet en los hogares ecuatorianos en 2013, incorporando sus características socioeconómicas dentro de un modelo de elección discreta que realiza estimaciones sobre la probabilidad del uso de internet dentro del hogar con base en los microdatos de la encuesta de uso de TIC. Los principales hallazgos sugieren que el ingreso y el grado de educación de los individuos ejercen las mayores influencias positivas en el u...

  16. Determinantes sociais e psicológicos do comportamento alimentar infantil

    OpenAIRE

    Andrade, Maria da Graça Massano de Amorim de Mavigné, 1961-

    2014-01-01

    Tese de doutoramento, Psicologia (Psicologia da Saúde), Universidade de Lisboa, Faculdade de Psicologia, 2014 A redução da taxa de crescimento da obesidade infantil é um dos principais objetivos de saúde, a nível nacional e internacional, o que reforça a importância da aquisição de hábitos alimentares saudáveis nos primeiros anos da infância. Uma vasta evidência empírica aponta para a influência de uma multiplicidade de determinantes do comportamento alimentar infantil, sendo contudo neces...

  17. No linealidad de la relación entre la estructura de capital y sus determinantes

    OpenAIRE

    Sánchez Vidal, Javier

    2009-01-01

    El objetivo del trabajo es analizar si los factores que condicionan el endeudamiento de una empresa varían su influencia según el nivel de endeudamiento de aquella, para así poder estudiar, por ejemplo, los determinantes de la deuda de las empresas más apalancadas. Con una muestra de datos de panel de 17.776 empresas durante el periodo 2001-2006 se realizan las estimaciones mediante regresiones cuantílicas. Los resultados muestran que la regresión por cuantiles proporciona una perspectiva más...

  18. Inseguridad alimentaria en los estados de México: un estudio de sus principales determinantes

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Díaz-Carreño

    2016-01-01

    Full Text Available Este artículo presenta un análisis de los principales factores determinantes de la inseguridad alimentaria severa en las entidades federativas de México, para lo cual se utilizó un modelo econométrico de regresión lineal múltiple. Los resultados sugieren que el fenómeno de la inseguridad alimentaria severa en los estados de México durante 2012 responde principalmente a las variables de escolaridad media y crecimiento de la producción per cápita del sector primario.

  19. Inseguridad alimentaria en los estados de México: un estudio de sus principales determinantes

    OpenAIRE

    Miguel Ángel Díaz-Carreño

    2016-01-01

    Este artículo presenta un análisis de los principales factores determinantes de la inseguridad alimentaria severa en las entidades federativas de México, para lo cual se utilizó un modelo econométrico de regresión lineal múltiple. Los resultados sugieren que el fenómeno de la inseguridad alimentaria severa en los estados de México durante 2012 responde principalmente a las variables de escolaridad media y crecimiento de la producción per cápita del sector primario.

  20. Determinantes del perfil de ahorro en Colombia : una estimación para hogares e individuos

    OpenAIRE

    Daza Báez, Nancy Aireth

    2011-01-01

    En este documento se presenta un análisis de los determinantes del perfil de ahorro para hogares e individuos con el objetivo de contrastar la Hipótesis de Ciclo de Vida, utilizando la metodología expuesta en Deaton y Paxson (2000a y 2000b) con datos de la Encuesta Nacional de Ingresos y Gastos (ENIG) para los periodos 1984-1985, 1994-1995 y 2006-2007. Se encontró que para el análisis por hogar no hay evidencia que determine el cumplimiento de la Hipótesis del Ciclo de Vida, mientras que para...

  1. DETERMINANTES DEL ACCESO AL CRÉDITO DE LOS HOGARES COLOMBIANOS

    OpenAIRE

    Andrés Murcia Pabón

    2007-01-01

    Este documento busca identificar los determinantes de acceso al crédito de los hogares colombianos y encuentra que características tales como el ingreso, la riqueza, la posición geográfica, el acceso a la seguridad social, el nivel de educación y la edad afectan la probabilidad de ser usuario de los servicios financieros acá analizados (tarjeta de crédito y crédito hipotecario). Adicionalmente se encontró que una porción importante de población cuenta con unas condiciones financieras favorabl...

  2. DETERMINANTES DEL ACCESO AL CRÉDITO DE LOS HOGARES COLOMBIANOS

    OpenAIRE

    Murcia Pabón, Andrés

    2007-01-01

    En este documento se busca identificar los determinantes de acceso al crédito de los hogar es colombianos; así, se encuentra que características tales como el ingreso, la riqueza, la posición geográfica, el acceso a la seguridad social, el nivel de educación y la edad influyen sobre la probabilidad de ser usuario de los servicios financieros acá analizados (tarjeta de crédito y crédito hipotecario). Adicionalmente, se encontró que una porción importante de población cuenta con unas condicione...

  3. Determinantes do desenvolvimento do setor agropecuário nos municípios

    Directory of Open Access Journals (Sweden)

    Caio César de Medeiros Costa

    2013-06-01

    Full Text Available Dada a importância do setor agropecuário para a economia brasileira, é fundamental conhecer os fatores determinantes do desenvolvimento agropecuário em seus municípios. Sob a luz de referencial teórico que aborda questões relacionadas aos fatores determinantes do desenvolvimento agropecuário e do desenvolvimento econômico local, neste estudo fez-se uso das metodologias de análise multivariada conhecidas como análise fatorial e análise de cluster. Utilizou-se o estado de Minas Gerais como recorte analítico. Foram selecionadas 22 variáveis para cada município, representando diferentes dimensões do desenvolvimento, visando verificar quais os fatores determinantes do desenvolvimento agropecuário. Após a análise fatorial, optou-se pela extração de seis fatores com raiz característica maior do que um e que respondem, em conjunto, por 62,25% da variância total dos dados: desenvolvimento econômico, investimento público, qualidade de vida, condições da atividade agropecuária, condições de meio ambiente e consumo, e condições de financiamento. Pela análise de cluster, foram criados cinco grupos, de acordo com o desempenho dos membros nos fatores. Os resultados corroboram os apontamentos literários em quase sua totalidade e, além disso, destaca-se e discute-se a existência de um ciclo positivo gerado pelo incremento dos fatores determinantes do desenvolvimento agropecuário e pelas vantagens competitivas. Neste estudo, aponta-se a importância do investimento público na promoção do desenvolvimento, reforçando o proposto por trabalhos anteriores de que o Estado desempenha papel fundamental para garantir condições que propiciem o desenvolvimento do setor agropecuário. Outra constatação factível é a de que fatores isolados, tais como as boas condições da agricultura e do meio ambiente, não são capazes de propiciar desenvolvimento para o setor nos municípios mineiros.

  4. La salud en la población inmigrante : la política como determinante social de la salud

    OpenAIRE

    González González, Javier

    2013-01-01

    Profundizar en el conocimiento de los Determinantes Estructurales de las Desigualdades de Salud con el fin de analizar su amplitud, estructura y consecuencias sobre la salud de la población inmigrante, a través del Modelo Conceptual de los Determinantes Sociales de las Desigualdades en Salud, es el objetivo principal de esta monografía. El concepto de salud adquiere diferentes significados dependiendo del contexto y de las personas. Es un derecho reconocido, así lo establece la Organización M...

  5. Determinantes de las dotaciones para los deterioros de las inversiones crediticias: ciclo contable, ciclo económico, morosidad

    OpenAIRE

    Climent Serrano, Salvador

    2015-01-01

    Este trabajo estudia los determinantes de las dotaciones para provisiones del deterioro de créditos en las entidades de crédito españolas desde 1983 al segundo trimestre de 2013. Como determinantes resultan significativos, además de la morosidad, las provisiones genéricas, el margen de interés, la estacionalidad centrada en el cuarto trimestre y los periodos de crisis. Al ser un periodo extenso en el que la economía ha tenido hasta cuatro ciclos, se estudian cómo actúan los ...

  6. Los determinantes de la orientación exportadora y los resultados en las pymes exportadoras en Colombia

    OpenAIRE

    Diana Marcela Escandón Barbosa; Andrea Hurtado Ayala

    2014-01-01

    Partiendo del concepto de orientación al mercado definido en el campo del marketing internacional, este artículo analiza los factores determinantes de la orientación exportadora y su influencia en los resulta- dos empresariales de las pymes exportadoras en Colombia. A partir de una encuesta realizada en 2011 a 297 pymes manufactureras colombianas, se estima un modelo de redes neuronales tipo perceptrón mul- ticapa para establecer la importancia de los determinantes de la orientación exportado...

  7. Determinismo-indeterminismo y el debate de los determinantes-determinación social de la salud

    OpenAIRE

    Peñaranda, Fernando; Rendón, Carlos E

    2013-01-01

    El debate entre determinantes sociales de la salud o determinación social de la salud, promovido por la medicina social latinoamericana a raíz de la propuesta presentada por la Comisión sobre los Determinantes Sociales de la Salud de la OMS, pasa por analizar la tensión entre determinismo e indeterminismo y sus repercusiones para concebir la causalidad desde un punto de vista histórico y epistemológico. Este artículo presenta algunas tendencias sobre la visión cosmológica y epistemológica en ...

  8. Observadores: un rol determinante en el acoso escolar

    Directory of Open Access Journals (Sweden)

    María Clara Cuevas

    2016-01-01

    Full Text Available Objetivo. Examinar el rol de los observadores en el acoso escolar (AE, dada la escasez de estudios realizados que ilustren de manera específica su relevancia dentro del fenómeno y las razones asociadas a la adopción de su rol. Método. Se examinan estudios y teorías relevantes en la materia que contribuyen con datos sobre prevalencia, comportamientos asociados, cogniciones, emociones y otros elementos claves que permiten visualizar áreas en las cuales se deben focalizar las intervenciones para prevenir e intervenir en el AE, con énfasis en el rol de los participantes. Se revisaron las bases de datos electrónicas ProQuest Psychology Journals, PsycINFO, PSICODOC, PsycARTICLES, Psychology and Behavioral Sciences Collection; además se utilizaron como palabras clave bystanders, bullying, group process, por separado, sin restricción de campo, sin límite temporal, en los idiomas inglés y español. También, se consultaron portales de internet especializados en el tema como PrevNet, Organización Mundial de la Salud (OMS, Kivaprogram.net, Anti-bullying Alliance y Stopbullying.gov. Resultados. Se identificaron y describieron diversos niveles de abordaje del fenómeno, definición, prevalencia, características y algunas explicaciones sobre su causalidad Conclusión. El rol de observadores, participantes mayoritarios del AE, cobra especial relevancia en quienes con sus comportamientos instigan, alientan, apoyan y contribuyen con actos intimidatorios o, en su defecto, realizan acciones para detenerlos.

  9. Fatores determinantes do crescimento infantil Determinant factors of infant growth

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    Sylvia de Azevedo Mello Romani

    2004-03-01

    Full Text Available Esta revisão enfoca os fatores que interferem no crescimento de crianças nos primeiros anos de vida. Foram utilizadas informações de artigos publicados em revistas científicas, teses e publicações de organizações internacionais. O crescimento infantil se constitui em um dos melhores indicadores de saúde da criança e o retardo estatural representa atualmente, a característica antropométrica mais representativa do quadro epidemiológico da desnutrição no Brasil. Ressaltando a importância do fator genético no crescimento, a revisão abrange com maior ênfase a atuação dos fatores extrínsecos, sabendo-se que o processo de crescimento resulta da interação entre a carga genética e os fatores do meio ambiente, os quais premitirão a maior ou menor expressão do potencial genético. Face a comprovada natureza multicausal do crescimento infantil, vários estudos têm sido desenvolvidos, buscando relacionar variáveis biológicas, socioeconômicas, maternas, ambientais, culturais, demográficas, nutricionais, entre outras, com a sua etiologia, seu desenvolvimento e sua manutenção. A revisão apresentada reforça o interesse em investigações sobre o crescimento na primeira infância que devem ser permanentes, devido, principalmente, às repercussões a longo prazo sobre a saúde infantil.This review focuses on factors interfering with growth during the first years of life. Information was collected from articles published in indexed scientific journals, theses, technical books and publications of international organizations. Infant growth is one of the best health indicators, and linear growth retardation is currently the most representative anthropometric characteristic of child nutrition epidemiology in Brazil. The review indicates the value of genetics in growth, focusing, however on the influence of the extrinsic factors. Growth process results from interaction between genetic and environmental factors, determining variation

  10. DETERMINANTES DEL PRECIO DE VIVIENDAS EN LA REGIÓN METROPOLITANA DE CHILE

    Directory of Open Access Journals (Sweden)

    Andrés Sagner T

    2011-01-01

    Full Text Available Este artículo analiza econométricamente los factores que determinaron la dinámi-ca de precios del sector residencial en la región metropolitana de Chile durante elperiodo 1990-2007. Los resultados muestran que la antigüedad y superficie son de-terminantes estadísticamente significativos en la formación del precio; el acceso aestaciones del Metro tiende a capitalizarse de forma no lineal, y tanto el ingreso delhogar como el agregado son variables económicamente significativas. La descompo-sición de precios revela que entre 68 a 71% del monto es explicado por determinantesrelacionados con los atributos de la propiedad, mientras que cerca de 68% del creci-miento observado entre 1990 y 2007 es consecuencia de determinantes macrofinan-cieros. Durante el periodo 2006-2007 la evolución de precios inmobiliarios no difierede manera significativa de la predicha por el modelo. Los resultados encontrados sonrobustos a estimaciones por tipo de vivienda y subperiodos muestrales.

  11. EL PERFIL COMPETITIVO LOCAL COMO FACTOR DETERMINANTE PARA EL DESARROLLO DE LA FLORICULTURA EN MADRID (CUNDINAMARCA

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    DANIEL HERNÁN SANTIAGO ROMERO

    2011-01-01

    Full Text Available Este artículo describe los atributos del perfil competitivo del municipio de Madrid y establece las relaciones que, con dicho perfil, ha tenido el desarrollo de cultivos de flores. Se parte de la descripción de la situación actual de la industria de la floricultura en el país. Después, tras establecer los determinantes que desde la teoría se han propuesto para medir la competitividad de un territorio, se analiza el caso particular del municipio de Madrid y define los atributos competitivos que lo caracterizan. Se presentan las relaciones entre el perfil competitivo del municipio y la floricultura, mostrando cómo aquél, se convirtió en un factor determinante para dicha actividad económica. Finalmente se presentan las conclusiones del artículo, las cuales son antecedidas por la presentación de los elementos que representan la mayor fortaleza para el desarrollo económico del municipio en el futuro.

  12. Estudio multinivel basado em PISA 2009: determinantes del rendimiento educativo em Uruguay

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    Vivian Tatiane Rodrigues Yuane

    2015-12-01

    Full Text Available Los resultados de PISA 2009 manifiestan que el nivel educativo de los estudiantes Uruguayos se sitúa en una posición por debajo del promedio de los países de la OCDE, además, el promedio de los mismos discrepa entre las regiones del país. Frente a eso, este ensayo se propone a analizar los determinantes del desempeño estudiantil basado en los factores que tradicionalmente la literatura ha identificado como determinantes de la eficacia escolar. Dichos factores están relacionados con el propio alumno, con el centro educativo al que pertenece, su familia y su situación socioeconómica. Este ensayo además, procura controlar los aspectos regionales, para ello, la metodología empleada en este estudio es la regresión multinivel con la que es posible considerar la estructura jerárquica de las variables, el modelo incluye tres niveles: alumno, escuelas y regiones. Los resultados muestran que el nivel educativo de los padres, la calificación de los profesores y el nivel socioeconómico de los alumnos que concurren a la misma escuela, cuanto mayor sean sus valores correspondientes, mayor es el resultado esperado en el rendimiento de los alumnos en el área de comprensión lectora.

  13. DETERMINANTES DE LA PROBABILIDAD DE CIERRE DE NUEVAS EMPRESAS EN BOGOTÁ

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    JUAN FELIPE PARRA

    2011-01-01

    Full Text Available El artículo analiza los determinantes de la probabilidad de cerrar una firma nueva en el mercado antes de que alcance sus primeros cinco años de actividades. Se estudian las condiciones macroeconómicas y microeconómicas que experimentaron estas empresas en Bogotá durante su primer lustro. El estudio revela que hay indicios para afirmar que el tamaño óptimo de entrada es el de pequeña y mediana empresa (PYMEs. Entre los principales hallazgos de la investigación están, en primer lugar, que las empresas más proclives a la quiebra prematura son las microempresas, en segundo lugar, para algunas empresas el endeudamiento moderado puede ser útil para apalancarse, pero el alto endeudamiento, finalmente, se verificó que, tanto el sector económico, como la localidad en la que abre sus puertas la nueva empresa, son determinantes en su probabilidad de cerrar antes de los primeros cinco años.

  14. No linealidad de la relación entre la estructura de capital y sus determinantes

    Directory of Open Access Journals (Sweden)

    Javier Sánchez Vidal

    2009-06-01

    Full Text Available El objetivo del trabajo es analizar si los factores que condicionan el endeudamiento de una empresa varían su influencia según el nivel de endeudamiento de aquella, para así poder estudiar, por ejemplo, los determinantes de la deuda de las empresas más apalancadas. Con una muestra de datos de panel de 17.776 empresas durante el periodo 2001-2006 se realizan las estimaciones mediante regresiones cuantílicas. Los resultados muestran que la regresión por cuantiles proporciona una perspectiva más completa de los determinantes del endeudamiento que la regresión MCO estándar. El apalancamiento se ve condicionado por un comportamiento jerárquico, encontrándose asimismo evidencia de problemas de información asimétrica. Se constata una cierta preocupación de las empresas por los costes de dificultades financieras pero no por el escudo fiscal.

  15. Factores determinantes del nivel de compromiso medioambiental voluntario adquirido por los hoteles cotizados europeos

    Directory of Open Access Journals (Sweden)

    Patricia Milanés Montero

    2012-01-01

    Full Text Available Ante las importantes presiones que la actividad hotelera ejerce sobre el medioambiente, la ausencia de regulación de las actuaciones responsables y la escasez de investigaciones al respecto aparece la imperiosa necesidad de aportar luz en este sentido. Por ello, en este trabajo se analiza el compromiso medioambiental corporativo de los hoteles cotizados europeos; se utiliza como metodología el análisis de contenidos y se detectan los factores determinantes de las actuaciones responsables con el medioambiente con el propósito de contribuir a la construcción de un marco de referencia objetivo de medida de los avances en sostenibilidad de la actividad turística. Además, se contribuye al "argumento comercial" analizando la relación existente entre la rentabilidad empresarial y el desempeño medioambiental. Los resultados muestran que la mayoría de los hoteles analizados carece de política de protección medioambiental; asimismo, el tamaño, la normativa contable adoptada y la pertenencia a grupos son factores determinantes de la adopción de una postura más o menos responsable. Por otro lado, la rentabilidad empresarial resulta ser una de las ventajas de la integración de las cuestiones medioambientales en la estrategia corporativa de las empresas.

  16. Determinants of beta diversity: the relative importance of environmental and spatial processes in structuring phytoplankton communities in an Amazonian floodplain Determinantes da diversidade beta: a importância relativa de processos ambientais e espaciais na estrutura de comunidades fitoplanctônicas de uma planície de inundação amazônica

    Directory of Open Access Journals (Sweden)

    Ina de Souza Nogueira

    2010-09-01

    Full Text Available AIM: Beta diversity is defined as the change in species composition along environmental gradients, and in the present study, we investigated the influence of local (i.e., environmental and regional (i.e., dispersal factors in community structure. The aims of this study were to evaluate the beta diversity of phytoplankton communities in the Curuaí floodplain and to determine the relative importance of environmental and spatial processes in shaping phytoplankton community structure; METHOD: The phytoplankton communities were sampled in 16 lakes of the Curuaí floodplain (Amazon Basin during high-water periods in 2002 and 2003. We used partial redundancy analysis (pRDA to evaluate the pure effect of environmental (six variables and spatial (spatial filter variability on phytoplankton community composition; RESULTS: There were 156 taxa recorded in the two study years, including 122 algae species in 2002 and 66 algae species in 2003. The beta diversity that we measured (βSIM index was 0.889 in 2002 and 0.789 in 2003. The partitioning variation demonstrated that the majority of variation in phytoplankton community structure was not significantly explained by pure environmental and pure spatial components. However, environmental variables presented a larger coefficient of determination than the spatial variable; CONCLUSION: Other factors than those we measured in this study, such as local variables (i.e., biotic interactions, hydrology, etc. and stochastic events, affected the absence of significant results in our data. Therefore, we suggest that additional variables, such as biological interactions and other local factors, should be considered in this type of analysis to increase its explanatory power for understanding the variation of diversity in these communities.OBJETIVO: A diversidade beta é definida como as mudanças na composição de espécies ao longo de um gradiente ambiental, e atualmente, ecólogos têm investigado a influência de

  17. MINIMALISM IN A PSYCHOLINGUISTIC POINT OF VIEW: BINDING PRINCIPLES AND ITS OPERATION IN ON-LINE PROCESSING OF COREFERENCE

    Directory of Open Access Journals (Sweden)

    José Ferrari Neto

    2014-12-01

    Full Text Available This article aims to evaluate how much a formal model of Grammar can be apply to on-line mental processes that underlying the sentential processing. For this intent, it was carried on an experiment in which it was observed how the Binding Principles act in the processing of correferential relations in Brazilian Portuguese (BP. The results suggest that there is a convergence between linguistic computation and theories about linguistic processing.

  18. NJOY processed multigroup library for fast reactor applications and point data library for MCNP - Experience and validation

    International Nuclear Information System (INIS)

    Kim Jung-Do; Gil Choong-Sup

    1996-01-01

    JEF-1-based 50-group cross section library for fast reactor applications and point data library for continuous-energy Monte Carlo code MCNP have been generated using NJOY91.38 system. They have been examined by analyzing measured integral quantities such as criticality and central reaction rate ratios for 8 small fast critical assemblies. (author). 9 refs, 2 figs, 10 tabs

  19. Tecnologia 3G como Determinante de Custos: estudo em uma operadora de telefonia móvel

    Directory of Open Access Journals (Sweden)

    Marcos Antônio Souza

    2015-08-01

    Full Text Available O objetivo do artigo é verificar a influência da tecnologia 3G (tecnologia da terceira geração da telefonia móvel nos determinantes de custos de uma operadora de telefonia móvel localizada no Rio Grande do Sul. O estudo contempla os determinantes de custos sob a ótica e conceitos da vantagem competitiva desenvolvida por Porter (1989 e da gestão estratégica de custos discutida por Shank e Govindarajan (1997. Trata-se de um estudo de caso único, de natureza qualitativa e descritiva, desenvolvido no terceiro trimestre de 2013. A coleta e de dados deu-se por entrevistas semiestruturadas com gestores da empresa, análise documental e observações in loco. A análise dos dados ocorreu pelo confronto do conteúdo das três fontes utilizadas e em relação ao conteúdo apresentado pela literatura acerca do tema. Os principais achados da pesquisa indicam que a terceira geração da tecnologia da telefonia móvel desencadeou um processo de mudanças significativas em determinantes de custos estruturais e operacionais que, por conseguinte, refletiram na estrutura de custos da operadora e na alavancagem de receitas. A caracterização dessas mudanças evidencia consistência delas com a teoria desenvolvida sobre o tema determinantes de custos.

  20. Effect of the temperature and dew point of the decarburization process on the oxide subscale of a 3% silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Cesar, Maria das Gracas M.M. E-mail: gracamelo@acesita.com.br; Mantel, Marc J

    2003-01-01

    The oxide subscale formed on the decarburization annealing of 3% Si-Fe was investigated using microscopy and spectroscopy techniques. It was found that the morphology as well as the molecular structure of the subscale are affected by temperature and dew point. The results suggest that there is an optimum level of internal oxidation and an optimum fayalite/silica ratio in the subscale to achieve a oriented grain silicon steel having a continuous and smooth ceramic film and low core loss.

  1. Determinantes sociais e saúde bucal de adultos nas capitais do Brasil

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    Roberto Eduardo Bueno

    2014-07-01

    Full Text Available OBJETIVO: Investigar a correlação entre o índice Determinantes Sociais de Saúde Bucal (DSSB e indicadores sociais, indicadores de saúde bucal e determinantes sociais intermediários, representados pelos indicadores da Política Nacional de Saúde Bucal. MÉTODOS: Este estudo ecológico abrangeu 5 915 adultos de 35 a 44 anos em 27 capitais no Brasil. Os indicadores de desfechos em saúde bucal - perda dentária, dentes restaurados e Índice de Cuidados Odontológicos (ICO - foram obtidos do levantamento epidemiológico SB Brasil 2010. Os indicadores sociais (determinantes sociais estruturais e da Política Nacional de Saúde Bucal foram obtidos de censos demográficos e do Ministério da Saúde. RESULTADOS: Uma correlação de Pearson (r moderada foi observada entre o índice DSSB e ICO (r = 0,580, dentes restaurados (r = 0,545 e perda dentária (r = - 0,490. Houve uma correlação forte do componente equidade social com o ICO (r = 0,856, dentes restaurados (r = 0,822 e perda dentária (r = -0,665. Não houve associação estatisticamente significativa desses desfechos em saúde bucal com os componentes relativos à atenção primária e secundária à saúde bucal. O componente equidade social explicou 44% da variância da perda dentária, 68% da variância de dentes restaurados e 73% da variância do ICO. CONCLUSÕES: O índice DSSB e seu componente equidade social se correlacionaram significativamente com desfechos em saúde bucal de adultos nas capitais brasileiras. Portanto, políticas equitativas devem priorizar ações direcionadas aos DSSB, tais como ampliação da cobertura de saneamento e de água fluoretada, e redução da pobreza e das iniquidades regionais.

  2. Determinantes sociales de salud en los agricultores del resguardo indígena Zenú

    Directory of Open Access Journals (Sweden)

    Elsy C. Puello A.

    2016-04-01

    Full Text Available Objetivo: Analizar los determinantes sociales de salud presentes entre los indígenas agricultores del Resguardo Zenú de San Andrés de Sotavento. Metodología: Estudio descriptivo de corte, con enfoque cuantitativo, participaron 64 indígenas agricultores de las comunidades Celeste Imperio y Santa Elena del Municipio de San Andrés de Sotavento en el año 2012, se seleccionaron bajo la técnica del muestreo aleatorio simple. La recolección de la información se efectuó a través de encuestas estructuradas diligenciadas mediante entrevista. Resultados: El rango de edad de la población sujeto osciló entre 18 a 70 años, existe 41% de analfabetismo absoluto, las familias son extensas con orientación endogámica, las condiciones de vida son precarias, hay ausencia de actividad recreativa y actividad física programada, 97% percibe menos de un salario mínimo mensual legal vigente producto del trabajo comunitario, 95.3% pertenece al regimen de salud subsidiado, todos carecen de afiliación a riesgos laborales y pensión, 77% admitió que tuvo algún accidente laboral en el último año, así mismo, 70% manifestó morbilidad sentida relacionada con la actividad laboral. Conclusiones: Los determinantes de carácter social que influyen negativamente en la salud identificados fueron: sociopolítico, circunstancias materiales, factores biológicos, conductuales y laborales; los cuales se reflejan en deficiencias en su calidad de vida, morbilidad sentida, accidentalidad laboral, fragilidades en el Sistema de Protección Social, altos índices de analfabetismo absoluto, pobreza y características que indiscutiblemente reafirman la relación perversa e interdependiente entre analfabetismo, pobreza y salud. Sin embargo, la cohesión social se identificó como determinante social de influencia positiva para la salud (94%.

  3. Determinantes do spread bancário ex post no mercado brasileiro

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    José Alves Dantas

    2012-08-01

    Full Text Available A rentabilidade dos bancos é geralmente considerada um fator relevante para garantir a solidez do sistema financeiro, reduzindo os riscos associados aos eventos de insolvência nesse setor. No Brasil, porém, tem havido discussões quanto aos lucros das instituições financeiras que atuam no país, centradas no argumento de que tais lucros seriam supostamente muito elevados, onerando demasiadamente o setor produtivo. Por isso, diversos estudos têm avaliado a estrutura, a evolução e os determinantes do spread bancário, que é considerada a principal variável responsável pelos lucros supostamente anormais. Do ponto de vista metodológico, essas pesquisas têm se concentrado em investigar o spread ex ante das operações com recursos livres e têm utilizado fatores macroeconômicos como variáveis independentes. Este estudo busca identificar variáveis determinantes do spread bancário ex post, privilegiando variáveis explanatórias específicas das instituições, vale dizer, microeconômicas. Na literatura sobre determinantes do spread bancário ex post no Brasil, foi identificado apenas um trabalho anterior, o qual apresentou resultados pouco representativos, devido a um problema de micronumerosidade. Para evitar tal problema, este estudo utiliza dados dos balancetes de janeiro/2000 a outubro/2009 de instituições bancárias com carteira de crédito ativa. Utilizando um modelo de regressão com dados em painel dinâmico, são testadas nove hipóteses, constatando-se que o nível de spread ex post tem relação significativa e: 1. Positiva com o risco de crédito da carteira, com o grau de concentração do mercado de crédito e com o nível de atividade da economia; 2. negativa com a participação relativa da instituição no mercado de crédito. Por outro lado, não foram encontradas relações estatisticamente relevantes entre o spread ex post e: o nível de cobertura das despesas administrativas pelas receitas de prestações de

  4. Estratificación del bajo peso al nacer desde un enfoque de determinantes sociales

    Directory of Open Access Journals (Sweden)

    Hilda María Delgado Acosta

    2013-03-01

    Full Text Available Fundamento: el área materno-infantil requiere de un enfoque en sus determinantes para aumentar el alcance estratégico de sus programas. Objetivo: estratificar el bajo peso al nacer en el municipio de Cienfuegos y caracterizar el bajo peso de acuerdo a determinantes sociales seleccionadas. Métodos: se realizó un estudio epidemiológico, descriptivo, correlacional sobre la estratificación del bajo peso al nacer en los consejos populares del municipio Cienfuegos, en el período comprendido entre los años 2003 y 2007. Los estratos se definieron según el valor de la media del índice de bajo peso al nacer en este periodo. Para realizar el análisis de las variables cualitativas en muestras independientes se utilizó la prueba de independencia u homogeneidad utilizada en el caso de dos muestras con resultado dicotómico o más. El procesamiento estadístico se realizó en el programa SPSS versión 15,0 y se utilizaron como medidas matemáticas para las variables cualitativas el porcentaje, y para las variables cuantitativas la media aritmética. La técnica estadística para relacionar las variables fue la prueba Chi-cuadrado. Resultados: se mostraron diferencias estadísticamente significativas entre los estratos de bajo, mediano y alto riesgo, en el nivel de escolaridad, estado civil, ocupación, evaluación nutricional, hábito de fumar, antecedentes de bajo peso al nacer, período ínter genésico. La única enfermedad asociada que mostró diferencias entre ellos fue la hipertensión gestacional. Conclusiones: el bajo peso al nacer continúa siendo un serio problema de salud en el municipio Cienfuegos, cuestión esta que debe ser abordada desde sus determinantes para realizar intervenciones futuras y el logro de mejores resultados.

  5. Predicting wildfire occurrence distribution with spatial point process models and its uncertainty assessment: a case study in the Lake Tahoe Basin, USA

    Science.gov (United States)

    Jian Yang; Peter J. Weisberg; Thomas E. Dilts; E. Louise Loudermilk; Robert M. Scheller; Alison Stanton; Carl Skinner

    2015-01-01

    Strategic fire and fuel management planning benefits from detailed understanding of how wildfire occurrences are distributed spatially under current climate, and from predictive models of future wildfire occurrence given climate change scenarios. In this study, we fitted historical wildfire occurrence data from 1986 to 2009 to a suite of spatial point process (SPP)...

  6. Determinantes de la multilocalizaciónde empresas exportadoras de manufacturasen Colombia

    Directory of Open Access Journals (Sweden)

    Mónica María Sinisterra

    2009-01-01

    Full Text Available El objetivo de este artículo es investigar los determinantes de la multilocalización intrarregional de empresas exportadoras de manufacturas en Colombia para el año 2007. Para ello se utiliza un conjunto de datos de empresas, tomados de las bases de Proexport y la Superintendencia de Sociedades; asimismo se estima un modelo logit bivariado, que permite encontrar las características de las empresas exportadoras de manufacturas localizadas en más de un lugar del territorio nacional. Los resultados empíricos evidencian que las empresas exportadoras con mayor probabilidad de multilocalizarse en Colombia son las empresas grandes, no intensivas en capital, con altas ventas y un alto leverage.

  7. Determinantes del intercambio directo de drogas ilegales a pequeña escala en Cali

    Directory of Open Access Journals (Sweden)

    Bustamante Amaya Christian David

    2012-09-01

    Full Text Available Este documento centra su análisis en el estudio de los determinantes que explican el intercambio directo de drogas ilegales a pequeña escala en la ciudad de Cali, a partir de la estimación de modelos de datos de conteo. Se verifica el cumplimiento de los supuestos teóricos de la elección racional de los individuos que son esbozados en la economía del crimen. Los resultados del modelo sugieren que si un expendedor considera su actividad como riesgosa, reduce en una significativa cantidad el número de horas dedicadas al expendio. Por otra parte, el precio de un cigarrillo de marihuana afecta negativamente el número de veces que un individuo consume al día; no obstante, la magnitud del efecto para esta variable denota el alto grado de inelasticidad al precio que tiene el consumo de esta droga.

  8. Full Counting Statistics for Interacting Fermions with Determinantal Quantum Monte Carlo Simulations.

    Science.gov (United States)

    Humeniuk, Stephan; Büchler, Hans Peter

    2017-12-08

    We present a method for computing the full probability distribution function of quadratic observables such as particle number or magnetization for the Fermi-Hubbard model within the framework of determinantal quantum Monte Carlo calculations. Especially in cold atom experiments with single-site resolution, such a full counting statistics can be obtained from repeated projective measurements. We demonstrate that the full counting statistics can provide important information on the size of preformed pairs. Furthermore, we compute the full counting statistics of the staggered magnetization in the repulsive Hubbard model at half filling and find excellent agreement with recent experimental results. We show that current experiments are capable of probing the difference between the Hubbard model and the limiting Heisenberg model.

  9. Determinantes de la demanda por turismo hacia Cartagena, 1987-1998

    Directory of Open Access Journals (Sweden)

    Luis Armando Galvis,

    1999-07-01

    Full Text Available El presente documento se propone estudiar los factores que determinan la demanda de turismo nacional e internacional hacia la ciudad de Cartagena. Se evalúa el papel de la tasa de cambio real, utilizada como proxy de los precios relativos, y la capacidad de gasto nacional y extranjera, medida por el producto interno bruto (PIB, como determinante de la demanda turística. A partir de un modelo de cointegración estacional se concluye que la demanda de turismo es elástica al ingreso. También se encuentra que la demanda extranjera presenta una alta elasticidad precio, con lo cual la revaluación y los aumentos en los precios domésticos motivan una reducción en el gasto.

  10. Determinantes de la demanda de empleo en el sector manufacturero colombiano, 2000-2010

    Directory of Open Access Journals (Sweden)

    Jesús José Rodríguez de Luque

    2013-07-01

    Full Text Available En este artículo se estudian los determinantes de la demanda de empleo del personal profesional, administrativo y obrero en el sector manufacturero colombiano. Los resultados muestran que la demanda de personal obrero presenta el tiempo medio de ajuste más elevado y es la más sensible a cambios en los costos laborales totales. Estos resultados indican que el gobierno, por medio de políticas que reduzcan los costos laborales no salariales, puede incentivar la demanda de empleo poco calificado. Finalmente, se encuentra que en el corto (largo plazo la demanda de personal profesional (administrativo es la más sensible a cambios en la producción.

  11. Born-Infeld determinantal gravity and the taming of the conical singularity in 3-dimensional spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Ferraro, Rafael, E-mail: ferraro@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Fiorini, Franco, E-mail: franco@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina)

    2010-08-30

    In the context of Born-Infeld determinantal gravity formulated in an n-dimensional spacetime with absolute parallelism, we found an exact 3-dimensional vacuum circular symmetric solution without cosmological constant consisting in a rotating spacetime with non-singular behavior. The space behaves at infinity as the conical geometry typical of 3-dimensional General Relativity without cosmological constant. However, the solution has no conical singularity because the space ends at a minimal circle that no freely falling particle can ever reach in a finite proper time. The space is curved, but no divergences happen since the curvature invariants vanish at both asymptotic limits. Remarkably, this very mechanism also forbids the existence of closed timelike curves in such a spacetime.

  12. Born-Infeld determinantal gravity and the taming of the conical singularity in 3-dimensional spacetime

    International Nuclear Information System (INIS)

    Ferraro, Rafael; Fiorini, Franco

    2010-01-01

    In the context of Born-Infeld determinantal gravity formulated in an n-dimensional spacetime with absolute parallelism, we found an exact 3-dimensional vacuum circular symmetric solution without cosmological constant consisting in a rotating spacetime with non-singular behavior. The space behaves at infinity as the conical geometry typical of 3-dimensional General Relativity without cosmological constant. However, the solution has no conical singularity because the space ends at a minimal circle that no freely falling particle can ever reach in a finite proper time. The space is curved, but no divergences happen since the curvature invariants vanish at both asymptotic limits. Remarkably, this very mechanism also forbids the existence of closed timelike curves in such a spacetime.

  13. Múltiplos e seus determinantes: um estudo para o mercado de ações brasileiro

    OpenAIRE

    Arruda Filho, Rubens Paes de

    2015-01-01

    Esse trabalho tem como objetivo investigar a relação entre três múltiplos específicos (Preço/Lucro, Preço/Valor Patrimonial e Preço/Vendas) e seus determinantes (crescimento, payout ratio, risco, ROE e margem líquida), de acordo com a teoria apresentada por Aswath Damodaran. Para verificar essas relações, foram utilizadas duas metodologias econométricas distintas: A Regressão Linear Múltipla e o Modelo de Dados em Painel. Os dados coletados são referentes às empresas listadas no índice de açõ...

  14. Factores determinantes de la oferta exportadora láctea santafesina

    Directory of Open Access Journals (Sweden)

    Rodrigo García Arancibia

    2013-12-01

    Full Text Available El objetivo de este trabajo es conocer el impacto de algunos determinantes de la oferta exportadora de productos lácteos de la provincia de Santa Fe en el período 2000-2012. Para ello se propone un sistema de ecuaciones de oferta, modelando las exportaciones y el destino doméstico simultáneamente. Los resultados empíricos muestran que los precios de exportación, los precios mayoristas, la disponibilidad de leche cruda y variables coyunturales y estacionales resultan estadísticamente significativos para explicar la oferta externa e interna. Se concluye que las exportaciones son más inelásticas a sus propios precios que a los precios mayoristas internos, siendo muy elástica a la producción primaria.

  15. ESTRATÉGIA DO DESENVOLVIMENTO URBANO COMO FATOR DETERMINANTE PARA O DESENVOLVIMENTO INDUSTRIAL SUSTENTÁVEL

    Directory of Open Access Journals (Sweden)

    Rúbia Tânia Welter

    2016-11-01

    Full Text Available Este artigo tem por objetivo identificar a estratégia do desenvolvimento urbano como fator do desenvolvimento industrial sustentável. Para alcançar este objetivo, foi realizada uma pesquisa documental e uma revisão histórico-bibliográfica de uma cidade, neste caso, a cidade de Joinville-SC. Foi realizado, também, um estudo sobre a evolução dos acontecimentos históricos da cidade pesquisada, como forma de estabelecer que estratégias adotadas interferiram neste processo de desenvolvimento. Como resultado, foram identificados os fatores estratégicos inerentes ou determinantes para o desenvolvimento industrial da cidade. Palavras-chave: Desenvolvimento urbano. Desenvolvimento industrial. Fatores estratégicos.

  16. UNA MIRADA EMPíRICA A LOS DETERMINANTES DEL DESPLAZAMIENTO FORZADO EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Pérez Murcia

    2001-12-01

    Full Text Available Esta investigación propone un modelo empírico que falsea las distintas hipótesis explicativas sobre los determinantes del desplazamiento forzado. Según los resultados empíricos no se puede afirmar que los desplazamientos se presentan en los municipios ricos o pobres, pero sí se puede argumentar que se producen en zonas con gran potencial económico en donde por la existencia de fuertes mecanismos concentradores del ingreso, baja participación política y altos niveles de impunidad, las comunidades viven en condiciones de vulnerabilidad, que van más allá de la pobreza; el conflicto armado.

  17. Seed Dispersal, Microsites or Competition—What Drives Gap Regeneration in an Old-Growth Forest? An Application of Spatial Point Process Modelling

    Directory of Open Access Journals (Sweden)

    Georg Gratzer

    2018-04-01

    Full Text Available The spatial structure of trees is a template for forest dynamics and the outcome of a variety of processes in ecosystems. Identifying the contribution and magnitude of the different drivers is an age-old task in plant ecology. Recently, the modelling of a spatial point process was used to identify factors driving the spatial distribution of trees at stand scales. Processes driving the coexistence of trees, however, frequently unfold within gaps and questions on the role of resource heterogeneity within-gaps have become central issues in community ecology. We tested the applicability of a spatial point process modelling approach for quantifying the effects of seed dispersal, within gap light environment, microsite heterogeneity, and competition on the generation of within gap spatial structure of small tree seedlings in a temperate, old growth, mixed-species forest. By fitting a non-homogeneous Neyman–Scott point process model, we could disentangle the role of seed dispersal from niche partitioning for within gap tree establishment and did not detect seed densities as a factor explaining the clustering of small trees. We found only a very weak indication for partitioning of within gap light among the three species and detected a clear niche segregation of Picea abies (L. Karst. on nurse logs. The other two dominating species, Abies alba Mill. and Fagus sylvatica L., did not show signs of within gap segregation.

  18. Bienestar subjetivo, renta y bienes relacionales. Los determinantes de la felicidad en España

    Directory of Open Access Journals (Sweden)

    Iglesias Vázquez, Emma

    2013-12-01

    Full Text Available In the present paper we analyze the determinants of happiness proxying by subjective welfare. The main objective is twofold: on the one hand, to put to the test the Easterlin’s paradox (the lack of a direct relationship between income and subjective wellbeing at aggregate level and, on the other hand, to weight influence of relational goods in determining happiness. The analytical framework adopts the perspective of happiness economics and the empirical evidence is derived from the estimation of a microeconometric function of happiness applying a Logit model both when using cross sectional and panel data. The results show that in Spanish society income plays a secondary and subjective role, while other variables that are associated directly or indirectly to relational goods are revealed to be very important.En el presente trabajo se analizan los determinantes de la felicidad, entendida esta como satisfacción subjetiva revelada. El principal objetivo tiene un doble componente: por un lado, se trata de contrastar la paradoja de Easterlin para la sociedad española (ausencia de un vínculo directo entre el incremento de la renta per capita y la evolución del bienestar subjetivo revelado a nivel agregado y, por otro, evaluar el papel que desempeñan los bienes relacionales como determinantes de la felicidad. El marco analítico adoptado se encuadra dentro de la denominada happiness economics y la evidencia empírica se deriva de la estimación de una función microeconométrica de la felicidad aplicando un modelo Logit tanto en cortes temporales como en datos de panel. Los resultados obtenidos permiten concluir que en España el ingreso desempeña un papel secundario y subjetivo, mientras que se revelan como importantes las variables asociadas directa o indirectamente a los bienes relacionales.

  19. Determinantes de la Innovación Sustentable de las Empresas Ecuatorianas

    Directory of Open Access Journals (Sweden)

    Cynthia Lizbeth Román Bermeo

    2017-06-01

    protección ambiental aplicando técnicas de innovación sustentable. La innovación sustentable en las empresas radica en la necesidad de reducir los gases de efecto invernadero (GEI principales causantes de los efectos del cambio climático en el planeta. Los acuerdos para reducir los GEI alcanzados en la Conferencia de las Partes (COP en Paris en el año 2015, pusieron de manifiesto la urgencia que tienen las empresas y los gobiernos en redefinir sus estrategias empresariales. La redefinición de estrategias en las empresas no son sencillas, ya que, dependen del nivel de acción del gobierno ante la implementación de políticas públicas que incentiven, regulen y promueven la dinámica de los mercados. Por tanto, es importante analizar el nivel de vulnerabilidad que las empresas tienen por el cambio climático, de esta manera proponer estrategias de resilencia para la supervivencia de las empresas ecuatorianas en el largo plazo. A partir del uso de información de la encuesta de información ambiental económica de las empresas y mediante el uso de un modelo de Probit se identifica las principales determinantes que las empresas tienen para desarrollar estrategias de innovación sustentable. El tamaño de la empresa, y pertenecer a los sectores de Explotación de Minas y Manufacturas son determinantes al momento de realizar estrategias de innovación sustentable.

  20. Observation and investigation of a dynamic inflection point in current-voltage curves for roll-to-roll processed polymer photovoltaics

    DEFF Research Database (Denmark)

    Medford, Andrew James; Lilliedal, Mathilde Raad

    2010-01-01

    Inflection point behaviour is often observed in the current-voltage (IV) curve of polymer and organic solar cells. This phenomenon is examined in the context of flexible roll-to-roll (R2R) processed polymer solar cells in a large series of devices with a layer structure of: PET-ITO-ZnO-P3HT...... of this “photo-annealing” behaviour was further investigated by studying the effects of several key factors: temperature, illumination, and atmosphere. The results consistently showed that the inflection point is a dynamic interface phenomenon which can be removed under specific conditions. Subsequently...

  1. COST VOLUME PROFIT MODEL, THE BREAK -EVEN POINT AND THE DECISION MAKING PROCESS IN THE HOSPITALITY INDUSTRY

    Directory of Open Access Journals (Sweden)

    Scorte Carmen

    2010-12-01

    Full Text Available Management accounting and cost calculation in the hospitality industry is a pathless land. The prezent article is a starting point of a long scientific approach on the domain of the hospitality industry and on the managerial accounting in this area. Our intention is to put the spot light back on the thorny problem of applying Financial Accounting and specifically its implementation in the hospitality industry. One aim of this article is to provide a picture of CVP analysis in decision making with customizing the hospitality industry. To cope with the crisis period, the competition and to achieve the expected profits of the hospitality industry ,managers have the possibility to apply CVP analysis, one of the most simple and useful analytical tools. This paper will address the basic version of the CVP model, exemplifying the main indicators of the particular model for the hospitality industry that can help guide decision-making.

  2. Theory of transport processes in wood below the fiber saturation point. Physical background on the microscale and its macroscopic description

    DEFF Research Database (Denmark)

    Eitelberger, Johannes; Svensson, Staffan; Hofstetter, Karin

    2011-01-01

    transport when used to describe transient processes. A suitable modeling approach was found by distinguishing between the two phases of water in wood, namely bound water in the cell walls and water vapor in the lumens. Such models are capable of reproducing transient moisture transport processes......, but the physical origin of the coupling between the two phases remains unclear. In this paper, the physical background on the microscale is clarified and transformed into a comprehensive macroscopic description, ending up with a dual-scale model comprising three coupled differential equations for bound water...

  3. Critical points for spread-out self-avoiding walk, percolation and the contact process above the upper critical dimensions

    NARCIS (Netherlands)

    Hofstad, van der R.W.; Sakai, A.

    2005-01-01

    We consider self-avoiding walk and percolation in d, oriented percolation in d×+, and the contact process in d, with p D(·) being the coupling function whose range is proportional to L. For percolation, for example, each bond is independently occupied with probability p D(y–x). The above models are

  4. Flooding the Zone: A Ten-Point Approach to Assessing Critical Thinking as Part of the AACSB Accreditation Process

    Science.gov (United States)

    Cavaliere, Frank; Mayer, Bradley W.

    2012-01-01

    Undergoing the accreditation process of the Association to Advance Collegiate Schools of Business (AACSB) can be quite daunting and stressful. It requires prodigious amounts of planning, record-keeping, and document preparation. It is not something that can be thrown together at the last minute. The same is true of the five-year reaccreditation…

  5. Latin-american and maghrebian women migratory process and psychological adjustment: from a gender point of view

    Directory of Open Access Journals (Sweden)

    Edurne Elgorriaga

    2013-02-01

    Full Text Available This study examines the migratory process and psychological adjustment of immigrant women currently residing in the Basque Country. Perceived stress is analyzed in relationship with relevant psychosocial variables from a gender perspective.The sample consisted of 206 immigrant women, proceeding from Latin America (61.2% and Maghreb (38.8%.The participants’ self-assessment of migratory and well-beingwas in overall positive, however, the diffi culties derived from thisprocess, and the migratory changes, infl uence the psychologicaladjustment of immigrant women.Results revealed that perceived stress is affected by the migratory process, educational level, residential status, and the balance of their situation, the elements crossed by factors asgender and/or cultural origin.

  6. Choosing between Higher Moment Maximum Entropy Models and Its Application to Homogeneous Point Processes with Random Effects

    Directory of Open Access Journals (Sweden)

    Lotfi Khribi

    2017-12-01

    Full Text Available In the Bayesian framework, the usual choice of prior in the prediction of homogeneous Poisson processes with random effects is the gamma one. Here, we propose the use of higher order maximum entropy priors. Their advantage is illustrated in a simulation study and the choice of the best order is established by two goodness-of-fit criteria: Kullback–Leibler divergence and a discrepancy measure. This procedure is illustrated on a warranty data set from the automobile industry.

  7. Fermentation of Saccharomyces cerevisiae - Combining kinetic modeling and optimization techniques points out avenues to effective process design.

    Science.gov (United States)

    Scheiblauer, Johannes; Scheiner, Stefan; Joksch, Martin; Kavsek, Barbara

    2018-09-14

    A combined experimental/theoretical approach is presented, for improving the predictability of Saccharomyces cerevisiae fermentations. In particular, a mathematical model was developed explicitly taking into account the main mechanisms of the fermentation process, allowing for continuous computation of key process variables, including the biomass concentration and the respiratory quotient (RQ). For model calibration and experimental validation, batch and fed-batch fermentations were carried out. Comparison of the model-predicted biomass concentrations and RQ developments with the corresponding experimentally recorded values shows a remarkably good agreement for both batch and fed-batch processes, confirming the adequacy of the model. Furthermore, sensitivity studies were performed, in order to identify model parameters whose variations have significant effects on the model predictions: our model responds with significant sensitivity to the variations of only six parameters. These studies provide a valuable basis for model reduction, as also demonstrated in this paper. Finally, optimization-based parametric studies demonstrate how our model can be utilized for improving the efficiency of Saccharomyces cerevisiae fermentations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. On the thermochemical conversions of hard coal pitches in the process of raising the softening point to 358-363 K

    Energy Technology Data Exchange (ETDEWEB)

    Kekin, N.A.; Belkina, T.V.; Stepanenko, M.A.; Gordienko, V.G.

    1983-09-01

    High resolution paramagnetic resonance and infrared spectroscopy are used to obtain data on the nature of changes in hydrogen content of various groups in the substances of soluble functions in raw pitch and its thermoproducts during the process of producing binders with an increased softening point of 358-363 K. It was shown that thermal treatment of pitch during the process of raising the softening point leads to enrichment of the pitch structure with aromatic hydrogen and to reduction in the structure of the hydrogen in aliphatic bonds. The basis of these conversions is the splitting off of CH/SUB/3 groups and the formation of new structures containing CH/SUB/2 groups. (11 refs.)

  9. El coste de oportunidad como determinante del autoempleo en la Unión Europea (UE 25

    Directory of Open Access Journals (Sweden)

    Luis Miguel Zapico Aldeano

    2008-06-01

    Full Text Available Este trabajo pretende introducir en el análisis de la motivación de la actividad emprendedora el potencial efecto negativo del coste de oportunidad asociado a la misma. Para lograr este objetivo se aplicó un análisis de ecuaciones estructurales con la aproximación Partial Least Squares (PLS sobre una muestra de ciudadanos de la Unión Europea agrupados por países, para el periodo 2004. Los resultados muestran que la motivación emprendedora presenta una estructura interna dual formada por dos componentes independientes, uno relacionado con el atractivo intrínseco del autoempleo y otro relacionado con el atractivo intrínseco del estatus de empleado. Concretamente, los resultados indican una influencia directamente proporcional, sobre la intención emprendedora, de los elementos asociados al atractivo de ser empresario. También se verifica la relación inversamente proporcional de los elementos asociados al atractivo de ser empleado; siendo este efecto desmotivador de menor cuantía que el citado en primer lugar. Desde un punto de vista práctico, se plantea que las políticas de estímulo de la actividad emprendedora deberían tener en cuenta que no únicamente los ciudadanos con actitudes negativas hacia el autoempleo rechazan crear empresas, el atractivo del empleo por cuenta ajena es un determinante adicional significativo.This paper tries to include the potential negative effect of the opportunity cost over the motivation analysis related to the entrepreneurial activity. According to this aim, a Structural Equation Modelling analysis with Partial Least Squares (PLS approach was performed over a sample of European citizens clustered by country, within the period 2004. The results show that entrepreneurial motivation has a dual internal structure based on two independent components, one connected to the intrinsic attractiveness of self-employment and another one connected to the intrinsic attractiveness of the employee status

  10. ASSESSMENT OF THE INQUIRY-BASED PROJECT IMPLEMENTATION PROCESS IN SCIENCE EDUCATION UPON STUDENTS’ POINTS OF VIEWS

    Directory of Open Access Journals (Sweden)

    Orhan AKINOGLU

    2008-01-01

    Full Text Available Aim of the study is to assess how students in 6th, 7th and 8th grades of primary education see the project works made in science education and their implementation processes. The study was fulfilled upon the descriptive survey model to collect data. Participants of the research were 100 students who had project implementation experiences in science education, and they were from 24 primary schools in 7 districts randomly chosen in the city of Istanbul in Turkey. Data of the study were collected by using a semi-constructed interview form offered to students during the 2005-2006 teaching year. In the research, following items were examined: The extent to which students are inspired from the previously made projects during their own project selection process, the level of scientific document survey and the effects of contemporary events, science and technology class topics and students’ interest areas. It was seen that internet is the mostly used source to obtain information. For students, one of the most problematic issues faced during the project implementation is the time limits set out by teacher. It was found that the most obvious benefit obtained by students from the project works is their increasing interest towards science and technology class. The most significant change seen by students regarding project preparation is their increasing grades in exams during and following the project works.

  11. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  12. Interaction between α-calcium sulfate hemihydrate and superplasticizer from the point of adsorption characteristics, hydration and hardening process

    International Nuclear Information System (INIS)

    Guan Baohong; Ye Qingqing; Zhang Jiali; Lou Wenbin; Wu Zhongbiao

    2010-01-01

    Superplasticizers (SPs), namely sulfonated melamine formaldehyde (SMF) and polycarboxylate (PC), were independently admixed with α-calcium sulfate hemihydrate based plaster to improve the material's performance. SMF and PC gave, respectively, 38% and 25% increases in the 2 h bending strength at the optimum dosages of 0.5 wt.% and 0.3 wt.%, which are determined essentially by the maximum water-reducing efficiency. The peak shift of binding energy of Ca2p 3/2 detected by X-ray photoelectron spectroscopy (XPS) suggests that SPs are chemically adsorbed on gypsum surface. A careful examination of the strength development of set plaster allowed the hydration and hardening process to be divided roughly into five stages. SMF accelerates early hydration, while PC decelerates it. Both SPs allowed similar maximum water reductions, giving a more compact structure and a decrease in total pore volume and average pore diameter, and thus leading to higher strengths in the hardened plasters with SPs.

  13. Determinantes sociales en el deporte adaptado en la etapa de formación deportiva. un enfoque cuantitativo

    OpenAIRE

    Neira Tolosa, Nury Angelica; Alvis Gomez, Karim Martina

    2013-01-01

    Objetivo Identificar y analizar cuantitativamente los determinantes sociales que influyen en la inclusión/ exclusión de la población adolescente en situación de discapacidad al deporte de alto rendimiento.Método Estudio descriptivo de orden transversal, en 19 deportistas entre los 12-19 años de edad con discapacidad física y sensorial y 17 funcionarios del Instituto Distrital de Recreación y Deporte. Con aplicación de encuestas tipo Likert para cuatro categorías de análisis: Determinantes de ...

  14. PET and diagnostic technology evaluation in a global clinical process. DGN's point of view

    Energy Technology Data Exchange (ETDEWEB)

    Kotzerke, J. [Klinik und Poliklinik fuer Nuklearmedizin der Univ. Dresden (Germany); Dietlein, M. [Klinik und Poliklinik fuer Nuklearmedizin der Univ. Koeln (Germany); Gruenwald, F. [Klinik und Poliklinik fuer Nuklearmedizin der Univ. Frankfurt am Main (Germany); Bockisch, A. [Klinik und Poliklinik fuer Nuklearmedizin der Univ. Essen (Germany)

    2010-07-01

    The German Society of Nuclear Medicine (DGN) criticizes the methodological approach of the IQWiG for evaluation of PET and the conclusions, which represent the opposite point of view compared to the most other European countries and health companies in the USA: (1) Real integration of experienced physicians into the interpretation of data and the evaluation of effectiveness should be used for best possible reporting instead of only formal hearing. (2) Data of the National Oncologic PET Registry (NOPR) from the USA have shown, that PET has changed the therapeutic management in 38% of patients. (3) The decision of the IQWiG to accept outcome data only for their benefit analyses, is controversial. Medical knowledge is generated by different methods, and an actual analysis of the scientific guidelines has shown that only 15% out of all guidelines are based on the level of evidence demanded by the IQWiG. Health economics has created different assessment methods for the evaluation of a diagnostic procedure. The strategy chosen by the IQWiG overestimated the perspective of the population and undervalue the benefit for an individual patient. (4) PET evaluates the effectiveness of a therapeutic procedure, but does not create an effective therapy. When the predictive value of PET is already implemented in a specific study design and the result of PET define a specific management, the trial evaluate the whole algorithm and PET is part of this algorithm only. When PET is implemented as test during chemotherapy or by the end of chemotherapy, the predictive value of PET will depend decisively on the effectiveness of the therapy: The better the therapy, the smaller the differences in survival detected by PET. (5) The significance of an optimal staging by the integration of PET will increase. Rationale is the actual development of ''titration'' of chemotherapy intensity and radiation dose towards the lowest possible, just about effective dosage. (6) The medical

  15. A novel knot selection method for the error-bounded B-spline curve fitting of sampling points in the measuring process

    International Nuclear Information System (INIS)

    Liang, Fusheng; Zhao, Ji; Ji, Shijun; Zhang, Bing; Fan, Cheng

    2017-01-01

    The B-spline curve has been widely used in the reconstruction of measurement data. The error-bounded sampling points reconstruction can be achieved by the knot addition method (KAM) based B-spline curve fitting. In KAM, the selection pattern of initial knot vector has been associated with the ultimate necessary number of knots. This paper provides a novel initial knots selection method to condense the knot vector required for the error-bounded B-spline curve fitting. The initial knots are determined by the distribution of features which include the chord length (arc length) and bending degree (curvature) contained in the discrete sampling points. Firstly, the sampling points are fitted into an approximate B-spline curve Gs with intensively uniform knot vector to substitute the description of the feature of the sampling points. The feature integral of Gs is built as a monotone increasing function in an analytic form. Then, the initial knots are selected according to the constant increment of the feature integral. After that, an iterative knot insertion (IKI) process starting from the initial knots is introduced to improve the fitting precision, and the ultimate knot vector for the error-bounded B-spline curve fitting is achieved. Lastly, two simulations and the measurement experiment are provided, and the results indicate that the proposed knot selection method can reduce the number of ultimate knots available. (paper)

  16. A Comparative Study of Applying Active-Set and Interior Point Methods in MPC for Controlling Nonlinear pH Process

    Directory of Open Access Journals (Sweden)

    Syam Syafiie

    2014-06-01

    Full Text Available A comparative study of Model Predictive Control (MPC using active-set method and interior point methods is proposed as a control technique for highly non-linear pH process. The process is a strong acid-strong base system. A strong acid of hydrochloric acid (HCl and a strong base of sodium hydroxide (NaOH with the presence of buffer solution sodium bicarbonate (NaHCO3 are used in a neutralization process flowing into reactor. The non-linear pH neutralization model governed in this process is presented by multi-linear models. Performance of both controllers is studied by evaluating its ability of set-point tracking and disturbance-rejection. Besides, the optimization time is compared between these two methods; both MPC shows the similar performance with no overshoot, offset, and oscillation. However, the conventional active-set method gives a shorter control action time for small scale optimization problem compared to MPC using IPM method for pH control.

  17. Constraints and/or determinants of return to sexual activity in the puerperium Condicionantes y/o determinantes del retorno a la actividad sexual en el puerperio Condicionantes e/ou determinantes do retorno à atividade sexual no puerpério

    Directory of Open Access Journals (Sweden)

    Cleci de Fátima Enderle

    2013-06-01

    Full Text Available OBJECTIVE: to identify factors which constrain or determine the return to sexual activity in the puerperium. METHOD: exploratory and descriptive study undertaken in a university hospital in the South of Brazil. Fifteen women who had recently given birth, who received a consultation with the nurse in the period August - October 2011, took part in the study. Data was collected after the consultation had finished through semi-structured interviews, in which the women who had recently given birth were asked about the return to sexual activity and the feelings involved in this process. RESULTS: the principal determinant/constraint for return to sexual activity in the post-natal period was the fear of a new pregnancy. Fear of feeling pain, permission from the health professional, shame of their own bodies and changes in libido emerged as constraining and/or determinant factors in the thematic analysis. CONCLUSION: it is considered fundamental for the issue of contraception to be addressed with the woman/couple during the pre-natal consultation, so that there may be opportunities for reflection and dialog prior to the critical time itself. OBJETIVO: identificar factores que condicionan y/o determinan el retorno de las actividades sexuales en el puerperio. MÉTODO: estudio exploratorio y descriptivo desarrollado en un hospital universitario del Sur de Brasil. Hicieron parte del estudio 15 puérperas que realizaron la consulta de enfermería, en el período de agosto a octubre de 2011. La recolección de datos aconteció por entrevista semiestructurada, después del término de la consulta, preguntándoles sobre el retorno de la actividad sexual y las sensaciones involucradas en este proceso. RESULTADOS: el miedo de un nuevo embarazo fue el principal determinante/condicionante del retorno sexual en el posparto. En el análisis temático sobresalieron como factores condicionantes y/o determinantes, el miedo de sentir dolor, la liberación del profesional

  18. DETERMINANTES INDIVIDUALES Y DEL ENTORNO RESIDENCIAL EN LA PERCEPCIÓN DE SEGURIDAD EN BARRIOS DEL GRAN SANTIAGO, CHILE

    Directory of Open Access Journals (Sweden)

    Ximena Tocornal

    2012-01-01

    Full Text Available La percepción de seguridad de los habitantes en sus entornos residenciales más inmediatos se nutre de diversos factores tanto personales como del territorio y de las relaciones sociales entre vecinos. Este trabajo explora mediante el método estadístico de Regresión Lineal Multivariada los principales determinantes de la percepción individual de seguridad. Esta metodología se aplica con una perspectiva multinivel que considera el nivel de determinantes individuales (sexo, edad, años de educación, ingreso del hogar, como el nivel de determinantes de las relaciones sociales y del territorio residencial del individuo. Los resultados a nivel de variables individuales son coherentes con la evidencia previa. Diversas variables asociadas a la interacción social en el barrio inciden en la percepción de seguridad. En particular, con¿ anza e interacción entre vecinos junto a la antigüedad de los barrios son relevantes en la determinación de la percepción de seguridad. El rol de las señales de desorden físico no parece relevante. La presencia de programas de seguridad ciudadana a nivel municipal en el territorio es signi¿ cativa, indicando la relevancia de estas iniciativas en frenar el temor de las comunidades.

  19. Determinantes de la precarización laboral en Argentina entre 2003-2013. Entre los cambios y las continuidades

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    Marcelo Delfini

    2016-06-01

    Full Text Available El crecimiento económico experimentado por Argentina desde 2003 ha tenido su correlato en la mejora de los indicadores laborales. No obstante, la precarización laboral se ha mantenido, luego de una baja importante, hasta 2007, en valores muy elevados. Partiendo de la idea central que la precarización constituye para el capital una reducción de costos, el objetivo de este artículo es dar cuenta de los determinantes de la informalidad entre los trabajadores asalariados y establecer continuidades y cambios durante 2003 y 2013. Para ello, utilizamos una metodología cuantitativa con fuentes secundarias de información, dde acuerdo con las cuales realizamos dos tipo de análisis: el primero de carácter descriptivo, a partir del cual se busca dar cuenta de las características del mercado de trabajo argentino durante 1990 y 2013, y el segundo se realiza por medio de una regresión logística binomial, que permite acercarnos a los determinantes de la precarización de las condiciones de trabajo. En este sentido, se pudo observar que durante 2003 y 2013 se consolidó una precarización laboral, cuyos determinantes no lograron modificarse sustancialmente durante los años de referencia

  20. Determinantes de la precarización laboral en Argentina entre 2003-2013: entre los cambios y las continuidades

    Directory of Open Access Journals (Sweden)

    Marcelo Delfini

    2016-03-01

    Full Text Available El crecimiento económico experimentado por Argentina desde 2003 ha tenido su correlato en la mejora de los indicadores laborales. No obstante, la precarización laboral se ha mantenido, luego de una baja importante hasta el año 2007, en valores muy elevados. Partiendo de la idea central que la precarización constituye para el capital, una reducción de costos, el objetivo de este artículo es dar cuenta de los determinantes de la informalidad entre los trabajadores asalariados, estableciendo continuidades y cambios entre los años 2003 y 2013. Para ello utilizamos una metodología cuantitativa con fuentes secundarias de información, a partir de las cuales realizamos dos tipo de análisis, el primero de carácter descriptivo a partir del cual se busca dar cuenta de las características del mercado de trabajo argentino entre 1990 y 2013 y el segundo se realiza por medio de una regresión logística binomial, que permite acercarnos a los determinantes de la precarización de las condiciones de trabajo. En este sentido, se pudo observar que entre los años 2003 y 2013, se consolidó una precarización laboral, cuyos determinantes no lograron modificarse sustancialmente entre los años de referencia.

  1. Collision Visualization of a Laser-Scanned Point Cloud of Streets and a Festival Float Model Used for the Revival of a Traditional Procession Route

    Science.gov (United States)

    Li, W.; Shigeta, K.; Hasegawa, K.; Li, L.; Yano, K.; Tanaka, S.

    2017-09-01

    Recently, laser-scanning technology, especially mobile mapping systems (MMSs), has been applied to measure 3D urban scenes. Thus, it has become possible to simulate a traditional cultural event in a virtual space constructed using measured point clouds. In this paper, we take the festival float procession in the Gion Festival that has a long history in Kyoto City, Japan. The city government plans to revive the original procession route that is narrow and not used at present. For the revival, it is important to know whether a festival float collides with houses, billboards, electric wires or other objects along the original route. Therefore, in this paper, we propose a method for visualizing the collisions of point cloud objects. The advantageous features of our method are (1) a see-through visualization with a correct depth feel that is helpful to robustly determine the collision areas, (2) the ability to visualize areas of high collision risk as well as real collision areas, and (3) the ability to highlight target visualized areas by increasing the point densities there.

  2. Fabrication of an infrared Shack-Hartmann sensor by combining high-speed single-point diamond milling and precision compression molding processes.

    Science.gov (United States)

    Zhang, Lin; Zhou, Wenchen; Naples, Neil J; Yi, Allen Y

    2018-05-01

    A novel fabrication method by combining high-speed single-point diamond milling and precision compression molding processes for fabrication of discontinuous freeform microlens arrays was proposed. Compared with slow tool servo diamond broaching, high-speed single-point diamond milling was selected for its flexibility in the fabrication of true 3D optical surfaces with discontinuous features. The advantage of single-point diamond milling is that the surface features can be constructed sequentially by spacing the axes of a virtual spindle at arbitrary positions based on the combination of rotational and translational motions of both the high-speed spindle and linear slides. By employing this method, each micro-lenslet was regarded as a microstructure cell by passing the axis of the virtual spindle through the vertex of each cell. An optimization arithmetic based on minimum-area fabrication was introduced to the machining process to further increase the machining efficiency. After the mold insert was machined, it was employed to replicate the microlens array onto chalcogenide glass. In the ensuing optical measurement, the self-built Shack-Hartmann wavefront sensor was proven to be accurate in detecting an infrared wavefront by both experiments and numerical simulation. The combined results showed that precision compression molding of chalcogenide glasses could be an economic and precision optical fabrication technology for high-volume production of infrared optics.

  3. COLLISION VISUALIZATION OF A LASER-SCANNED POINT CLOUD OF STREETS AND A FESTIVAL FLOAT MODEL USED FOR THE REVIVAL OF A TRADITIONAL PROCESSION ROUTE

    Directory of Open Access Journals (Sweden)

    W. Li

    2017-09-01

    Full Text Available Recently, laser-scanning technology, especially mobile mapping systems (MMSs, has been applied to measure 3D urban scenes. Thus, it has become possible to simulate a traditional cultural event in a virtual space constructed using measured point clouds. In this paper, we take the festival float procession in the Gion Festival that has a long history in Kyoto City, Japan. The city government plans to revive the original procession route that is narrow and not used at present. For the revival, it is important to know whether a festival float collides with houses, billboards, electric wires or other objects along the original route. Therefore, in this paper, we propose a method for visualizing the collisions of point cloud objects. The advantageous features of our method are (1 a see-through visualization with a correct depth feel that is helpful to robustly determine the collision areas, (2 the ability to visualize areas of high collision risk as well as real collision areas, and (3 the ability to highlight target visualized areas by increasing the point densities there.

  4. Cognitive and emotional processing of pleasant and unpleasant experiences in major depression: A matter of vantage point?

    Science.gov (United States)

    Pfaltz, Monique C; Wu, Gwyneth W Y; Liu, Guanyu; Tankersley, Amelia P; Stilley, Ashley M; Plichta, Michael M; McNally, Richard J

    2017-03-01

    In nonclinical populations, adopting a third-person perspective as opposed to a first-person perspective while analyzing negative emotional experiences fosters understanding of these experiences and reduces negative emotional reactivity. We assessed whether this generalizes to people with major depression (MD). Additionally, we assessed whether the emotion-reducing effects of adopting a third-person perspective also occur when subjects with MD and HC subjects analyze positive experiences. Seventy-two MD subjects and 82 HC subjects analyzed a happy and a negative experience from either a first-person or a third-person perspective. Unexpectedly, we found no emotion-reducing effects of third-person perspective in either group thinking about negative events. However, across groups, third-person perspective was associated with less recounting of negative experiences and with a clearer, more coherent understanding of them. Negative affect decreased and positive affect increased in both groups analyzing happy experiences. In MD subjects, decreases in depressive affect were stronger for the third-person perspective. In both groups, positive affect increased and negative affect decreased more strongly for the third-person perspective. While reflecting on their positive memory, MD subjects adopted their assigned perspective for a shorter amount of time (70%) than HC subjects (78%). However, percentage of time participants adopted their assigned perspective was unrelated to the significant effects we found. Both people suffering from MD and healthy individuals may benefit from processing pleasant experiences, especially when adopting a self-distant perspective. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Food safety and nutritional quality for the prevention of non communicable diseases: the Nutrient, hazard Analysis and Critical Control Point process (NACCP).

    Science.gov (United States)

    Di Renzo, Laura; Colica, Carmen; Carraro, Alberto; Cenci Goga, Beniamino; Marsella, Luigi Tonino; Botta, Roberto; Colombo, Maria Laura; Gratteri, Santo; Chang, Ting Fa Margherita; Droli, Maurizio; Sarlo, Francesca; De Lorenzo, Antonino

    2015-04-23

    The important role of food and nutrition in public health is being increasingly recognized as crucial for its potential impact on health-related quality of life and the economy, both at the societal and individual levels. The prevalence of non-communicable diseases calls for a reformulation of our view of food. The Hazard Analysis and Critical Control Point (HACCP) system, first implemented in the EU with the Directive 43/93/CEE, later replaced by Regulation CE 178/2002 and Regulation CE 852/2004, is the internationally agreed approach for food safety control. Our aim is to develop a new procedure for the assessment of the Nutrient, hazard Analysis and Critical Control Point (NACCP) process, for total quality management (TMQ), and optimize nutritional levels. NACCP was based on four general principles: i) guarantee of health maintenance; ii) evaluate and assure the nutritional quality of food and TMQ; iii) give correct information to the consumers; iv) ensure an ethical profit. There are three stages for the application of the NACCP process: 1) application of NACCP for quality principles; 2) application of NACCP for health principals; 3) implementation of the NACCP process. The actions are: 1) identification of nutritional markers, which must remain intact throughout the food supply chain; 2) identification of critical control points which must monitored in order to minimize the likelihood of a reduction in quality; 3) establishment of critical limits to maintain adequate levels of nutrient; 4) establishment, and implementation of effective monitoring procedures of critical control points; 5) establishment of corrective actions; 6) identification of metabolic biomarkers; 7) evaluation of the effects of food intake, through the application of specific clinical trials; 8) establishment of procedures for consumer information; 9) implementation of the Health claim Regulation EU 1924/2006; 10) starting a training program. We calculate the risk assessment as follows

  6. Exceso de confianza como determinante de la volatilidad en mercados accionarios Latinoamericanos

    Directory of Open Access Journals (Sweden)

    Arturo Lorenzo Valdés

    2016-01-01

    Full Text Available Proponemos un modelo EGARCH con una distribución t de Student estandarizada para las innovaciones. El modelo se usa para describir el comportamiento de la volatilidad de las series de rendimientos de los índices bursátiles para 6 economías latinoamericanas. A la ecuación de la varianza condicional se le agregan factores que representan el exceso de confianza de los inversionistas con lo que se busca determinar si este sesgo cognitivo afecta la volatilidad de los rendimientos. Los resultados sugieren que: 1 Las series de rendimientos analizadas pueden describirse adecuadamente con el modelo propuesto; 2 se cumple la característica de efecto apalancamiento en las series de rendimientos de Chile, Colombia, México y Perú; 3 en general se puede afirmar que el exceso de confianza es un determinante de la volatilidad; y 4 en periodos de crisis se pierde la confianza en los mercados financieros, principalmente el mexicano.

  7. Determinantes del trabajo infantil y la escolaridad: el caso del Valle del Cauca en Colombia

    Directory of Open Access Journals (Sweden)

    Sebastián Urueña Abadía

    2009-10-01

    Full Text Available Colombia, al igual que la mayoría de países latinoamericanos, consciente de las repercusiones sociales y económicas negativas del trabajo infantil, se ha comprometido en la lucha por la erradicación de este fenómeno. Prueba de ello es la ratificación por parte del gobierno colombiano en el año 2007, del Convenio 182 de la OIT sobre la Prohibición de las Peores Formas de Trabajo Infantil y la Acción Inmediata para su Eliminación. En el plano regional, como parte del Plan de Desarrollo del Departamento del Valle del Cauca 2008-2011, se está implementando actualmente una estrategia territorial de erradicación del trabajo infantil en sus 42 municipios. Considerando este panorama, este trabajo indaga cuáles son los determinantes del trabajo infantil y la escolaridad en el departamento del Valle a partir de los datos de la Encuesta Nacional de Calidad de Vida del año 2003. Para el análisis se emplea un modelo econométrico Probit Bivariado, que permite el estudio conjunto e interrelacionado de decisiones diferentes, en este caso la asistencia escolar y el trabajo.

  8. Características del conocimiento transferido como determinantes del rendimiento de los sistemas de franquicia

    Directory of Open Access Journals (Sweden)

    Beatriz Minguela Rata

    2009-06-01

    Full Text Available En este trabajo se pretende analizar la influencia de la naturaleza tácita y el valor del conocimiento (dos características del conocimiento determinantes de la facilidad con la que se puede transferir el mismo en el rendimiento de los sistemas de franquicia. Se ha llevado a cabo un análisis de regresión lineal sobre una muestra de establecimientos franquiciados en diferentes cadenas de franquicia y sectores de actividad que operan en España, midiendo el rendimiento tanto de manera objetiva como subjetiva y tomando el tipo de actividad llevada a cabo por el establecimiento franquiciado como variable de control. Los resultados parecen indicar que la naturaleza tácita del conocimiento influye de manera negativa en el rendimiento de los sistemas de franquicia mientras que el valor del conocimiento afecta de manera positiva.In this paper the influence of tacitness and value of knowledge on the performance of franchise systems are studied. With this aim, a linear regression analysis is conducted on a sample of franchisee of different franchise chains and sectors of activity operating in Spain. In the model we added a control variable, named transformation, which representa the kind of activities carried out in the franchisee units: just commercial or transformative and commercial activities. The findings show that tacit knowledge has a negative impact on franchise systems performance, the value of knowledge affects it in a positive manner whereas the control variable is significant.

  9. Salud y ruralidad en Colombia: análisis desde los determinantes sociales de la salud

    Directory of Open Access Journals (Sweden)

    Diana R. Rodríguez-Triana

    2016-09-01

    Full Text Available La salud es un concepto que ha tenido diferentes transformaciones. Actualmente, a nivel mundial se promueve el término determinantes sociales, por tanto, ha sido apropiado por diferentes países para el desarrollo de políticas públicas en salud. Colombia ha acogido este concepto tanto en el plan nacional de desarrollo como en el plan decenal de salud pública. Por otro lado, el concepto de ruralidad ha cambiado, lo cual incide en las políticas públicas y decisiones que impactan en las poblaciones. La presente investigación se centró en un ejercicio de revisión sobre la ruralidad y el sistema de acceso a la salud en Colombia, así como de las propuestas de desarrollo rural en el país. El objetivo fue reflexionar sobre dos preguntas: i ¿qué tan viable es mantener un sistema de aseguramiento con las características del sgsss en la ruralidad colombiana?, ii ¿lo ofertado por este régimen puede dar solución a los impactos asociados con condiciones de vida y las diferencias en necesidades básicas? Lo anterior busca proponer nuevos ejercicios investigativos, nuevos marcos de aproximarse a la ruralidad y la relación de esta con la salud.

  10. Factores determinantes de la lealtad al proveedor de servicios turísticos online

    Directory of Open Access Journals (Sweden)

    Silvia Sanz Blas

    2013-01-01

    Full Text Available El objetivo de este estudio es analizar los factores determinantes de la lealtad hacia los proveedores de servicios turísticos online a través de un modelo integrador de la influencia de la confianza en las webs turísticas con el marco conceptual de la teoría del comportamiento planificado (Theory of Planned Behaviour, TPB. El contraste de hipótesis se ha realizado a partir de una muestra de 305 compradores de billetes de avión en sitios online; para ello se utilizaron modelos de ecuaciones estructurales. Los resultados del estudio empírico indican que los constructos de dicha teoría (control percibido, norma subjetiva y actitud ejercen una influencia significativa sobre la lealtad hacia el uso de Internet para la compra de billetes de avión. A su vez, cabe destacar la influencia positiva de la confianza en las variables del TPB. Finalmente, se plantean un conjunto de implicaciones relevantes para la gestión de empresas.

  11. Determinantes da Rotatividade das Carteiras dos Fundos de Investimento em Ações

    Directory of Open Access Journals (Sweden)

    Pedro Luiz Albertin Bono Milan

    2015-01-01

    Full Text Available A gestão ativa de um fundo de investimento em ações visa a obter um desempenho superior ao retorno de uma carteira de mercado por meio da rotatividade da carteira do fundo. Este trabalho procura evidenciar, no mercado brasileiro, os determinantes dos índices de rotatividade das carteiras dos fundos de investimentos em ações de gestão ativa. Usando a metodologia de Gaspar, Massa e Matos (2005, este estudo evidencia as características dos fundos e dos gestores impactando o nível de rotatividade das carteiras dos fundos. Fundos grandes e fundos que cobram valores altos para depósito inicial tendem a apresentar elevada rotatividade da carteira. Gestores com mais tempo dedicado ao mesmo fundo tendem a apresentar elevados índices de rotatividade. No entanto quanto maior a experiência do gestor em gestão de fundos, menor tende a ser a rotatividade da carteira do fundo. Gestores formados em administração de empresas tendem a apresentar maiores índices de rotatividade da carteira do que os gestores formados em economia e engenharia.

  12. Las familias saludables y los factores determinantes del estado de salud

    Directory of Open Access Journals (Sweden)

    Amado Rodríguez Calzadilla

    2001-12-01

    Full Text Available Se realizó un estudio descriptivo transversal con 30 familias, escogidas al azar, de 3 áreas de salud. Cada familia se relacionó con los factores determinantes del estado de salud. Se utilizó como instrumento para la recogida de la información la historia de salud bucal familiar y su respectivo instructivo. Se seleccionaron los aspectos a estudiar y se determinaron valores cuantitativos para evaluar familias saludables, moderadamente saludables y no saludables. Se describe un método sencillo para identificar resultados comparables entre uno y otro diagnóstico cada año, o período de 2 años. Finalmente se presenta el ciclo de calidad de las familias saludables y las estrategias para lograrlo.A descriptive cross-sectional study was conducted among 30 families selected at random from 3 health areas. Each family was related to the determinants of the health status. The family history of oral health and its respective instructions were used as a tool for gathering information. The aspects to be studied were chosen and the quantitative values were determined to evaluate healthy, moderately healthy and unhealthy families. A simple method to identify comparable results between one diagnosis and the other every year or for 2 years was described. Finally, the quality cycle of the healthy families and the strategies to attain it were presented.

  13. Determinantes en el proceso del despliegue del valor para la innovación

    Directory of Open Access Journals (Sweden)

    Juan Mejía Trejo

    2016-03-01

    Full Text Available El estudio tiene como objetivo hallar las determinantes en el proceso del despliegue del valor para la innovación de productos. la metodología, basada en investigación documental, descubre tres áreas: I: qfd modificado, donde se consideran las percepciones ponderadas del consumidor de necesidades, satisfacción y desempeño de los diferentes atributos y características de los productos y servicios a través de voces denominadas: del consumidor, la mercadotecnia, la tecnología, los requerimientos y la firma; área II: valorprecio y costo de retención del consumidor, en la que se calcula el precio justo del producto objetivo a innovar respecto de sus competidores y costo de retener al consumidor; área III: difusión de la innovación, que permite visualizar el mercado de adoptadores del producto objetivo a innovar. El proceso es posible visualizarlo en un solo plano, por lo que se propone su denominación como despliegue del valor para la innovación de productos (dvip.

  14. UNA MIRADA EMPíRICA A LOS DETERMINANTES DEL DESPLAZAMIENTO FORZADO EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Pérez Murcia

    2001-12-01

    Full Text Available Esta investigación propone un modelo empírico que falsea las distintas hipótesis explicativas sobre los determinantes del desplazamiento forzado. Según los resultados empíricos no se puede afirmar que los desplazamientos se presentan en los municipios ricos o pobres, pero sí se puede argumentar que se producen en zonas con gran potencial económico en donde por la existencia de fuertes mecanismos concentradores del ingreso, baja participación política y altos niveles de impunidad, las comunidades viven en condiciones de vulnerabilidad, que van más allá de la pobreza; el conflicto armado.This research tries to pose an empirical model that denies the different alternative hypothesis about the determinants of forced displacement in Colombia. According to the empirical resul ts it is not correct to state that displacements take place in rich or poor counties, but it is correct to argue that displacements take place in areas of great economic potential in which, given the existence of strong income concentration mechanisms, scarce political participa tion and high impuni ty levels, the communities live under vulnerable condi tions tha t go beyond poverty; armed conflict

  15. Relaciones entre los determinantes de la calidad de las universidades: un estudio exploratorio desde Chile

    Directory of Open Access Journals (Sweden)

    Emilio Rodríguez Ponce

    2013-01-01

    Full Text Available El objetivo de la investigación es describir la relación entre la calidad de la docencia de pregrado, de la investigación, del postgrado, la vinculación con el medio, y la gestión institucional. Para este efecto, se trabaja con una muestra de 45 universidades chilenas, que han participado en los procesos de acreditación institucional dirigidos por la Comisión Nacional de Acreditación de Chile. Se dirigió un cuestionario con preguntas de tipo Likert con el fin de ser contestado por un miembro del equipo de gestión. La información obtenida fue procesada, en primera instancia por un análisis descriptivo de las variables y posteriormente se efectuó un análisis de correlaciones bivariadas de Pearson. Los resultados de la investigación sugieren que existe una correlación estadísticamente significativa y directa entre: docencia de pregrado, investigación, postgrado y gestión institucional. Se concluye que estos cuatro determinantes de la calidad están directa y significativamente relacionados entre sí. La vinculación con el medio se relaciona de manera significativa e inversa con la investigación.

  16. Determinantes del acceso al internet: Evidencia de los hogares del Ecuador

    Directory of Open Access Journals (Sweden)

    Héctor Alberto Botello-Peñaloza

    2015-01-01

    Full Text Available El objetivo del artículo se centra en investigar los determinantes del uso de Iinternet en los hogares ecuatorianos en 2013, incorporando sus características socioeconómicas dentro de un modelo de elección discreta que realiza estimaciones sobre la probabilidad del uso de internet dentro del hogar, con base en los microdatos de la encuesta de uso de TIC. Los principales hallazgos sugieren que el ingreso y el grado de educación de los individuos ejercen las mayores influencias positivas en el uso de internet, al igual que se evidencian brechas significativas de género, con un asentamiento en las áreas rurales más que en las urbanas, especialmente por la falta de infraestructura. Estos resultados destacan la importancia de la intervención pública en el aumento del acceso a las nuevas tecnologías, a la vez que el papel del capital humano en la reducción de las brechas sociales en Ecuador.

  17. Factores determinantes del ahorro interno en América Latina

    Directory of Open Access Journals (Sweden)

    Carlos Añez

    2002-01-01

    Full Text Available El siguiente artículo aborda el problema del financiamiento de la inversión para un país en desarrollo, específicamente de la América Latina, tratando de revisar la literatura disponible para llegar a conclusiones sobre cómo los determinantes del ahorro en todas sus versiones -ahorro externo, ahorro privado y ahorro público- ejercen influencia sobre el proceso de crecimiento. Aun cuando la dirección causal exacta entre ahorro y crecimiento no ha sido establecida, el desarrollo de políticas económicas que estimulen el ahorro interno por encima del procedente del exterior, fortalecerían la capacidad de inversión interna y, al existir una correlación positiva entre estas variables, se potencia el proceso de crecimiento aunque otras variables igualmente pueden difuminar tal efecto. Se concluye que el incremento de la relación Ahorro Interno / P. I. B. sólo puede alcanzarse a través de esfuerzos comunes entre empresas, gobierno y el sistema financiero de estas economías.

  18. Determinantes biopsicossociais do processo de inclusão laboral da pessoa estomizada

    Directory of Open Access Journals (Sweden)

    Vanessa Cristina Mauricio

    2014-06-01

    Full Text Available Estudo cujo objeto tratou dos determinantes biopsicossociais dos estomizados que facilitam e/ou dificultam sua inclusão laboral. Os objetivos foram identificar e analisar as dificuldades e facilidades das pessoas com estoma para inclusão no trabalho. Pesquisa descritivo-exploratória, qualitativa, realizada com 20 estomizados através de entrevista semiestruturada; utilizandose Análise Temática de Conteúdo. Os resultados revelaram que as principais dificuldades dos estomizados para adentrarem ao ambiente laboral foram a perda do controle esfincteriano, o isolamento social e a falta de oportunidades de empregos adequados à sua nova condição de saúde. Os principais agentes facilitadores foram a criação de banheiros adaptados e a flexibilidade de horários. Conclui-se que as mudanças biopsicossociais causadas pela presença do estoma podem dificultar a inclusão no trabalho do estomizado, porém, com o apoio social, podem-se criar condições flexíveis que os auxiliem em seu retorno às atividades laborativas.

  19. Determinantes de la presión fiscal en las empresas mexicanas durante 1992 - 2009

    Directory of Open Access Journals (Sweden)

    Elena Fernández-Rodríguez

    2016-01-01

    Full Text Available Este trabajo analiza los factores determinantes del Tipo Impositivo Efectivo (TIE soportado por las compañías cotizadas mexicanas por razón del impuesto sobre bene¿cios. Para ello, se utiliza un panel de datos extraídos de la base de datos Compustat correspondiente a 79 empresas durante el período 1992- 2009 y se aplica el estimador del método generalizado de los momentos en primeras diferencias (GMM diseñado por Arellano y Bond (1991. Los resultados obtenidos permiten concluir que el TIE soportado por estas compañías es mani¿estamente inferior al tipo estatutario y que la presión ¿scal de un ejercicio está condicionada por la soportada previamente. Además se constata una relación no lineal entre tamaño y TIE, soportando menor presión ¿scal las empresas más grandes. Asimismo, presentan menores TIEs cuando el coste de la deuda y las amortizaciones son más elevados.

  20. Obesidade na adolescência e seus principais fatores determinantes Obesity in adolescence and its main determinants

    Directory of Open Access Journals (Sweden)

    Carla Cristina Enes

    2010-03-01

    Full Text Available O objetivo deste trabalho foi discutir os principais fatores ambientais determinantes do sobrepeso e da obesidade em adolescentes, fundamentando-se em uma revisão crítica sobre o assunto. Para a revisão do tema foram consultadas as principais bases de dados nacionais e internacionais, entre elas, Medline/Pubmed, Web of Science, SciELO, Lilacs, compreendendo o período de 1975 a 2009. Os descritores e termos MeSH utilizados na busca foram: "sobrepeso", "obesidade", "adolescência", "adolescentes", "atividade física", "ingestão alimentar". Os resultados das pesquisas indicam que as mudanças ocorridas nos padrões alimentares nas últimas décadas, como o aumento do consumo de açúcares simples, alimentos industrializados e ingestão insuficiente de frutas e hortaliças, estão diretamente associadas ao ganho de peso dos adolescentes. Além disso, a redução progressiva da prática de atividade física combinada ao maior tempo dedicado às atividades de baixa intensidade, como assistir televisão, usar computador e jogar videogame, também tem contribuído para o aumento de peso dos jovens. Conclui-se, portanto, que as variáveis relacionadas ao padrão alimentar e de atividade física devem ser priorizadas nas intervenções voltadas para a prevenção da obesidade entre adolescentes.The objective of this paper was to discuss the main environmental factors determining overweight and obesity in adolescents, based on a critical review of the subject. The main national and international health databases, Medline/PubMed, Web of Science, SciELO, and Lilacs were searched including publications from 1975 to 2009. The following key-words and respective MeSH terms were used: "overweight", "obesity", "adolescence", "adolescents", "physical activity", "food intake". The findings showed that changes in dietary patterns in recent decades as the increased consumption of simple sugars, processed foods, and inadequate intake of fruits and vegetables have

  1. Research on an uplink carrier sense multiple access algorithm of large indoor visible light communication networks based on an optical hard core point process.

    Science.gov (United States)

    Nan, Zhufen; Chi, Xuefen

    2016-12-20

    The IEEE 802.15.7 protocol suggests that it could coordinate the channel access process based on the competitive method of carrier sensing. However, the directionality of light and randomness of diffuse reflection would give rise to a serious imperfect carrier sense (ICS) problem [e.g., hidden node (HN) problem and exposed node (EN) problem], which brings great challenges in realizing the optical carrier sense multiple access (CSMA) mechanism. In this paper, the carrier sense process implemented by diffuse reflection light is modeled as the choice of independent sets. We establish an ICS model with the presence of ENs and HNs for the multi-point to multi-point visible light communication (VLC) uplink communications system. Considering the severe optical ICS problem, an optical hard core point process (OHCPP) is developed, which characterizes the optical CSMA for the indoor VLC uplink communications system. Due to the limited coverage of the transmitted optical signal, in our OHCPP, the ENs within the transmitters' carrier sense region could be retained provided that they could not corrupt the ongoing communications. Moreover, because of the directionality of both light emitting diode (LED) transmitters and receivers, theoretical analysis of the HN problem becomes difficult. In this paper, we derive the closed-form expression for approximating the outage probability and transmission capacity of VLC networks with the presence of HNs and ENs. Simulation results validate the analysis and also show the existence of an optimal physical carrier-sensing threshold that maximizes the transmission capacity for a given emission angle of LED.

  2. Fixed Points

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

  4. Tipping Point

    Medline Plus

    Full Text Available ... 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  5. Determinantes Sociales de la Salud: postura oficial y perspectivas críticas / Social Determinants of Health: official stance and critical views

    Directory of Open Access Journals (Sweden)

    Myriam Acero A

    2013-08-01

    Full Text Available La relación entre las desigualdades socioeconómicas y el proceso salud enfermedad ha sido demostrada desde hace ya algún tiempo. Su estudio y posibilidades de intervención, han sido motivo de análisis de actores académicos e institucionales que asumen posturas según la ideología o corriente de pensamiento en la que se inscriben. Con el ánimo de analizar las causas de las inequidades en salud y hacer algunas recomendaciones, la Organización Mundial de la Salud estableció en el año 2005 la Comisión sobre Determinantes Sociales de la Salud. Perspectivas latinoamericanas como la Medicina Social y la Salud Colectiva reconocen la preocupación de la Organización Mundial de la Salud, sin embargo critican la posición asumida por la Comisión y organizan la discusión alrededor de los ejes conceptual, ético y de acción política, proponiendo, a diferencia de la Comisión, buscar las causas de la inequidad y sus vías de solución en lo que significa la determinación social. Cuestionamientos al enfoque de los determinantes sociales de la Comisión llegaron también desde autores como Vicente Navarro, para quien no son las desigualdades las que matan, sino los responsables de esas desigualdades, llamando la atención sobre las relaciones de poder que se ocultan y sobre los responsables y beneficiarios de la inequidad. Finalmente con el objetivo de analizar la determinación social y la ubicación jerárquica de los determinantes sociales, se presenta el problema del hambre, inscrito en un circuito de reproducción y determinación que permite ubicar la particularidad y la generalidad en permanente interrelación The relationship between socioeconomic inequalities and the health-disease process has long been demonstrated. Its study and possibilities for intervention have been submitted to analysis by academic and institutional actors which take more or less critical stances depending on their paradigms. In order to analyze the causes of

  6. Estratificación del bajo peso al nacer desde un enfoque de determinantes sociales Stratification of Low Birth Weight from a Social Determinants Approach

    Directory of Open Access Journals (Sweden)

    Meira Mileny Sotolongo Acosta

    2013-04-01

    Full Text Available Fundamento: el área materno-infantil requiere de un enfoque en sus determinantes para aumentar el alcance estratégico de sus programas. Objetivo: estratificar el bajo peso al nacer en el municipio de Cienfuegos y caracterizar el bajo peso de acuerdo a determinantes sociales seleccionadas. Métodos: se realizó un estudio epidemiológico, descriptivo, correlacional sobre la estratificación del bajo peso al nacer en los consejos populares del municipio Cienfuegos, en el período comprendido entre los años 2003 y 2007. Los estratos se definieron según el valor de la media del índice de bajo peso al nacer en este periodo. Para realizar el análisis de las variables cualitativas en muestras independientes se utilizó la prueba de independencia u homogeneidad utilizada en el caso de dos muestras con resultado dicotómico o más. El procesamiento estadístico se realizó en el programa SPSS versión 15,0 y se utilizaron como medidas matemáticas para las variables cualitativas el porcentaje, y para las variables cuantitativas la media aritmética. La técnica estadística para relacionar las variables fue la prueba Chi-cuadrado. Resultados: se mostraron diferencias estadísticamente significativas entre los estratos de bajo, mediano y alto riesgo, en el nivel de escolaridad, estado civil, ocupación, evaluación nutricional, hábito de fumar, antecedentes de bajo peso al nacer, período ínter genésico. La única enfermedad asociada que mostró diferencias entre ellos fue la hipertensión gestacional. Conclusiones: el bajo peso al nacer continúa siendo un serio problema de salud en el municipio Cienfuegos, cuestión esta que debe ser abordada desde sus determinantes para realizar intervenciones futuras y el logro de mejores resultados.Background: maternal-infant area requires a determinants approach in order to enhance the strategic reach of its programs. Objective: to stratify low birth weight in the municipality of Cienfuegos and to

  7. Galaxy clustering: a point process

    OpenAIRE

    Hurtado Gil, Lluis

    2016-01-01

    El 'clustering' de galàxies és l'agregació de galàxies en l'universe produida per la força de la gravetat. Les galàxies tendeixen a formar estructures de major tamany tal com 'clusters' o filaments que formen la xarxa còsmica ('Cosmic Web'). Aquesta Estructura a Gran Escala de l'Univers es pot entendre com el resultat de la distribució de galàxies, un procés en el qual totes les galàxies estan subjectes a forces comuns i comparteixen propietats universals. L'anàlisis d'aquesta distribució es ...

  8. System identification to characterize human use of ethanol based on generative point-process models of video games with ethanol rewards.

    Science.gov (United States)

    Ozil, Ipek; Plawecki, Martin H; Doerschuk, Peter C; O'Connor, Sean J

    2011-01-01

    The influence of family history and genetics on the risk for the development of abuse or dependence is a major theme in alcoholism research. Recent research have used endophenotypes and behavioral paradigms to help detect further genetic contributions to this disease. Electronic tasks, essentially video games, which provide alcohol as a reward in controlled environments and with specified exposures have been developed to explore some of the behavioral and subjective characteristics of individuals with or at risk for alcohol substance use disorders. A generative model (containing parameters with unknown values) of a simple game involving a progressive work paradigm is described along with the associated point process signal processing that allows system identification of the model. The system is demonstrated on human subject data. The same human subject completing the task under different circumstances, e.g., with larger and smaller alcohol reward values, is assigned different parameter values. Potential meanings of the different parameter values are described.

  9. Dew Point

    OpenAIRE

    Goldsmith, Shelly

    1999-01-01

    Dew Point was a solo exhibition originating at PriceWaterhouseCoopers Headquarters Gallery, London, UK and toured to the Centre de Documentacio i Museu Textil, Terrassa, Spain and Gallery Aoyama, Tokyo, Japan.

  10. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  11. Tipping Point

    Science.gov (United States)

    ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  12. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... see news reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The ...

  13. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... TV falls with about the same force as child falling from the third story of a building. ...

  14. Tipping Point

    Medline Plus

    Full Text Available ... Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture ... about horrible accidents involving young children and furniture, appliance and tv tip-overs. The force of a ...

  15. Los determinantes de la estructura de la madurez de la deuda corporativa. El caso de Chile

    Directory of Open Access Journals (Sweden)

    Francisco Castañeda González

    2017-01-01

    Full Text Available Antecedentes: El objetivo de este artículo es proveer un análisis empírico de los determinantes de la madurez de la deuda con plazo mayor a un año. La deuda analizada es aquella emitida como renta fija por empresas chilenas cotizadas en la Bolsa de Valores de Santiago, en Chile. La investigación se contextualiza en el marco de la teoría de costos de agencia, hipótesis fiscal y señalización por medio de la emisión de deuda.Métodos: Para llevar a cabo el análisis utilizaremos un panel de datos construido a partir de información financiera obtenida de Bloomberg, para un periodo comprendido entre los años 2002 y 2012. Con estos datos llevaremos a cabo una regresión agrupada, un modelo de datos de panel con efectos fijos y otro con efectos aleatorios.Resultados: Después de analizar una muestra de 434 observaciones para 50 empresas con 52.8% de su deuda con una madurez mayor a un año, una madurez de sus activos de 29.26 años y una tasa efectiva de impuestos de 18.2%, encontramos los siguientes resultados.La razón entre el valor de mercado y el valor en libros de la empresa es estadísticamente significativa y tiene el signo negativo esperado. También encontramos que tanto el tamaño como la regulación son estadísticamente significativos y tienen signo positivo. Los resultados obtenidos para la variable “Tasa efectiva de impuestos” no son estadísticamente significativos, lo que coincide con la evidencia internacional.Por otra parte, el coeficiente estimado para la madurez de los activos no es estadísticamente significativo, lo que contradice las ideas propuestas por Myers (1977. En cambio, la variable “calidad” es estadísticamente significativa a 5% de significancia en todas las regresiones; sin embargo, ésta no tiene el signo negativo que se esperaba.Finalmente, en su mayoría los resultados son consecuentes con la evidencia internacional, por lo que los determinantes de la madurez de la deuda en Chile son similares a

  16. Matemáticas empresariales :Estudio de los factores determinantes del rendimiento académico

    Directory of Open Access Journals (Sweden)

    González Veiga , M.C

    1998-01-01

    Full Text Available El objetivo de este trabajo es conocer los factores que influyen de manera significativa sobre el rendimiento de los alumnos en Matemáticas Empresariales. Con este fin, y basándonos en la literatura existente sobre el tema se propone un modelo donde se tienen en cuenta algunas de las variables que habitualmente se consideran más relevantes junto con factores específicos que afectan al problema que queremos analizar. Uno de los trabajos pioneros en este campo de obligada referencia en todos los estudios es el Informe Coleman, publicado en 1966 bajo el título "Equality of Educational Opportunity", donde se analizan los factores determinantes del rendimiento de más de medio millón de alumnos en USA. Los resultados del citado informe han sido objetos de múltiples controversias tanto por cuestiones técnicas como por las conclusiones que de él se extraen que básicamente son que los resultados escolares dependen sobre todo de la extracción social del alumno y por tanto la actividad educativa desarrollada en la escuela y la inversión en recursos o en la mejora de la capacitación del profesorado apenas tiene efectos sobre el rendimiento. Este trabajo es considerado como el punto de partida de muchos otros en los que se analiza la enseñanza como un proceso productivo donde el output educativo se obtiene a partir de una serie de inputs de diversa índole aportados por los estudiantes, las familias y el centro escolar

  17. Variables determinantes del drag-flick en jugadoras de hockey hierba

    Directory of Open Access Journals (Sweden)

    Cristina López de Subijana Hernández

    2012-12-01

    Full Text Available El penalti córner es una de las situaciones de juego más importantes en el hockey hierba. Las mujeres utilizan menos el drag-flick que los hombres. Los objetivos de este estudio fueron describir los parámetros cinemáticos del drag-flick en jugadoras especialistas y hallar las variables determinantes en el rendimiento en este gesto técnico en jugadoras de hockey. Se analizaron quince lanzamientos de cinco lanzadoras con 6 cámaras del sistema de captura automática VICON registrando a 250 Hz. Para la comparación de medias se utilizó un análisis no paramétrico Kruskall Wallis de un factor (sujeto. Aquellos parámetros en los que se hallaron diferencias significativas, se compararon por pares por medio de una U de Mann Whitney. Las jugadoras 1 (22,5 ± 0,9 m/s y 3 (22,6 ± 0,7 m/s registraron velocidades de salida de la bola superiores (p < 0,001 a todas las demás jugadoras (19,1 ± 0,7 m/s jugadora 2; 20,5 ± 0,4 m/s jugadora 4 y 19,9 ± 0,4 m/s jugadora 5. La jugadora 1 basa su aceleración final en un doble apoyo largo, con una secuencia de velocidades y una distancia recorrida lo más amplia posible. Sin embargo, jugadora 3 basa su velocidad en la carrera previa, y en una secuencia de movimientos explosiva. Las características individuales de cada jugadora juegan un papel importante en la elección de una estrategia técnica u otra de lanzamiento.

  18. Las líneas: elementos determinantes de la investigación

    Directory of Open Access Journals (Sweden)

    Omar Parra Rozo

    2009-01-01

    Full Text Available Como el trazo esencial que da figura y origen a lo existente, desde sus orígenes míticos hasta los razonamientos científicos y desde el diario transcurrir hasta las formas estéticas que de ella se derivan, la línea es el elemento constitutivo que proporciona sentido, horizonte y razón al conocimiento y al sentir humano. Los múltiples problemas que se originan en el contexto que rodea un hecho cotidiano, un experimento o una reflexión filosófica, un acto de fe o un asunto pedagógico, suscitan un planteamiento de propuestas y proyectos. La construcción y la reconstrucción de éstos, el esbozo metodológico, los procesos y los productos investigativos, su socialización y difusión tienen una raíz esencial: la línea que los origina. A partir del mito y la narrativa se consigue vislumbrar la génesis de la línea y su armazón determinante en el progreso del conocimiento, la docencia y la investigación. Se puede decir, merced a lo investigado, que se mantiene un descuido epistemológico en la explicación de la línea de conocimiento o de investigación que debe ser subsanado yendo a sus orígenes y visualizando su prospectiva, pues la línea constituye un referente imprescindible y estructural de cualquier proceso investigativo.

  19. Factores determinantes en la calidad del servicio sanitario en México: Caso ABC

    Directory of Open Access Journals (Sweden)

    Norma Angélica Pedraza-Melo

    2014-01-01

    Full Text Available El estudio tiene como objetivo identificar los factores determinantes en la calidad del servicio de salud desde la percepción del usuario en Tamaulipas, México. Se llevó a cabo mediante la estrategia de estudio de caso. Se aplicaron 120 cuestionarios a usuarios que voluntariamente decidieron participar. Para el análisis de fiabilidad de la escala se determinó el Alpha de Cronbach. Con base en el análisis factorial exploratorio se identificaron cinco factores que determinan la calidad de los servicios sanitarios en el hospital ABC. De acuerdo a la percepción de los usuarios, la calidad de los servicios en la unidad de análisis se categorizó en un nivel cercano a bueno en cuatro factores: trato al paciente y empatía, efectividad y oportunidad, tiempos de espera, seguridad y limpieza. Se identificó un factor, el de capacidad de respuesta, con la más baja valoración, en esta dimensión un porcentaje mayoritario (52.5% manifestó que el tiempo de espera en la consulta externa va de pésimo a regular; el 48.3 % de los usuarios calificó de nivel incipiente el servicio de urgencias; mientras que el 43.3% señaló que el tiempo de espera para las consultas de especialidad va de pésimo a regular. Al tratarse de un hospital certificado en estándares internacionales y con reconocimiento importante en su desempeño, los hallazgos del presente estudio evidencian áreas débiles en la prestación de los servicios sanitarios que ofrece.

  20. Uso de los blogs políticos: análisis de algunos factores determinantes

    Directory of Open Access Journals (Sweden)

    De Marco, Stefano

    2012-08-01

    Full Text Available This paper aims to explore the factors that lead an Internet user to type comments on a political blog in more detail. Specifically, we sought to find out what political variables influence this behaviour and what uses of the Internet seem to favour it. We also studied the effect of a number of socio-demographic control variables. To do this, we used the data from the 2007 survey on “The Internet and political participation” (ref. 2736, run by the Centro de Investigaciones Sociológicas. We began with an exploratory factor analysis, which was followed by a logistic regression. In order to exclude influences on the model due to the first-level of digital divide, the sample chosen for the analysis comprised Spanish Internet Users.

    Objetivo de este trabajo es avanzar en la comprensión de los determinantes que hacen que un internauta escriba comentarios en un blog político. Más en concreto, se ha decidido averiguar qué variables políticas influyen sobre este comportamiento y qué usos de Internet parecen favorecerlo. También se ha estudiado el efecto de algunas variables socio-demográficas de control. Para ello, se han utilizado los datos del estudio de 2007 “Internet y participación política” (ref. 2736 del Centro de Investigaciones Sociológicas. Se ha implementado un análisis factorial exploratorio y, en un segundo momento, una regresión logística. La muestra elegida para el análisis ha coincido con los internautas españoles, para así descartar influencias en el modelo debidas a la brecha digital de primer nivel.

  1. Determinantes da tensão do cuidador familiar de idosos dependentes Determinantes de la tensión del cuidador familiar de ancianos dependientes Determinatives of family caregiver's tension while caring the dependent elderly

    Directory of Open Access Journals (Sweden)

    Maria das Graças Melo Fernandes

    2009-02-01

    Full Text Available Este estudo objetivou investigar os determinantes da tensão do cuidador familiar de idosos dependentes. Sua efetividade se deu no cenário domiciliar, envolvendo trinta cuidadoras principais. Os dados foram coletados por meio de entrevista estruturada gravada. A análise dos dados objetivos foi feita mediante uma abordagem quantitativa. Os dados discursivos, coletados por meio da gravação da entrevista, por serem apreendidos a partir de um instrumento estruturado, dispensaram procedimento analítico, sendo distribuídos entre as questões a que se referiam no sentido de ampliar sua compreensão. Os resultados apontam que o fenômeno investigado se origina a partir de determinantes relacionados ao cuidador, aos déficits do idoso, à interação idoso/cuidador, ao ambiente, e às demandas de cuidado.Este estudio objetivó investigar los determinantes de la tensión del cuidador familiar de ancianos dependientes. Su efectividad se dio en el escenario domiciliar, envolviendo a treinta cuidadoras principales. Los datos fueron colectados por medio de entrevista estructurada grabada. El análisis de los datos objetivos fue hecho mediante un abordaje cuantitativo. Los datos discursivos, colectados por medio de la grabación de la entrevista, por ser aprehendidos a partir de un instrumento estructurado, dispensaron procedimiento analítico, siendo distribuidos entre las cuestiones a que se referían en el sentido de ampliar su comprensión. Los resultados apuntan que el fenómeno investigado se origina a partir de determinantes relacionados al cuidador, a los déficits del anciano, a la interacción anciano/cuidador, al ambiente, y a las demandas de cuidado.This study had as objective investigate the determinatives of the tension of the dependent elderly's family caregiver. Its accomplish happened in the domestic scenery, involving thirty principal caregivers. The data were collected by a recorded and estructured interview. The analyses of the

  2. Determinantes da tensão do cuidador familiar de idosos dependentes Determinantes de la tensión del cuidador familiar de ancianos dependientes Determinatives of the tension of the dependent elderly's family caregiver

    Directory of Open Access Journals (Sweden)

    Maria das Graças Melo Fernandes

    2009-06-01

    Full Text Available Este estudo objetivou investigar os determinantes da tensão do cuidador familiar de idosos dependentes. Sua efetividade se deu no cenário domiciliar, envolvendo trinta cuidadoras principais. Os dados foram coletados por meio de entrevista estruturada gravada. A análise dos dados objetivos foi feita mediante uma abordagem quantitativa. Os dados discursivos, coletados por meio da gravação da entrevista, por serem apreendidos a partir de um instrumento estruturado, dispensaram procedimento analítico, sendo distribuídos entre as questões a que se referiam no sentido de ampliar sua compreensão. Os resultados apontam que o fenômeno investigado se origina a partir de determinantes relacionados ao cuidador, aos déficits do idoso, à interação idoso/cuidador, ao ambiente, e às demandas de cuidado.Este estudio objetivó investigar los determinantes de la tensión del cuidador familiar de ancianos dependientes. Su efectividad se dio en el escenario domiciliar, envolviendo a treinta cuidadoras principales. Los datos fueron colectados por medio de entrevista estructurada grabada. El análisis de los datos objetivos fue hecho mediante un abordaje cuantitativo. Los datos discursivos, colectados por medio de la grabación de la entrevista, por ser aprehendidos a partir de un instrumento estructurado, dispensaron procedimiento analítico, siendo distribuidos entre las cuestiones a que se referían en el sentido de ampliar su comprensión. Los resultados apuntan que el fenómeno investigado se origina a partir de determinantes relacionados al cuidador, a los déficits del anciano, a la interacción anciano/cuidador, al ambiente, y a las demandas de cuidado.This study had as objective investigate the determinatives of the tension of the dependent elderly's family caregiver. Its accomplish happened in the domestic scenery, involving thirty principal caregivers. The data were collected by a recorded and estructured interview. The analyses of the

  3. Process analytical technology (PAT) approach to the formulation of thermosensitive protein-loaded pellets: Multi-point monitoring of temperature in a high-shear pelletization.

    Science.gov (United States)

    Kristó, Katalin; Kovács, Orsolya; Kelemen, András; Lajkó, Ferenc; Klivényi, Gábor; Jancsik, Béla; Pintye-Hódi, Klára; Regdon, Géza

    2016-12-01

    In the literature there are some publications about the effect of impeller and chopper speeds on product parameters. However, there is no information about the effect of temperature. Therefore our main aim was the investigation of elevated temperature and temperature distribution during pelletization in a high shear granulator according to process analytical technology. During our experimental work, pellets containing pepsin were formulated with a high-shear granulator. A specially designed chamber (Opulus Ltd.) was used for pelletization. This chamber contained four PyroButton-TH® sensors built in the wall and three PyroDiff® sensors 1, 2 and 3cm from the wall. The sensors were located in three different heights. The impeller and chopper speeds were set on the basis of 3 2 factorial design. The temperature was measured continuously in 7 different points during pelletization and the results were compared with the temperature values measured by the thermal sensor of the high-shear granulator. The optimization parameters were enzyme activity, average size, breaking hardness, surface free energy and aspect ratio. One of the novelties was the application of the specially designed chamber (Opulus Ltd.) for monitoring the temperature continuously in 7 different points during high-shear granulation. The other novelty of this study was the evaluation of the effect of temperature on the properties of pellets containing protein during high-shear pelletization. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Temperature dependence of the mechanical properties of melt-processed Dy-Ba-Cu-O bulk superconductors evaluated by three point bending tests

    International Nuclear Information System (INIS)

    Katagiri, K; Nyilas, A; Sato, T; Hatakeyama, Y; Hokari, T; Teshima, H; Iwamoto, A; Mito, T

    2006-01-01

    Dy-Ba-Cu-O bulk superconductor has an excellent capability of trapping magnetic flux and lower heat conductivity at cryogenic temperatures as compared with Y-Ba-Cu-O bulk superconductor. The Young's modulus and the bending strength in the range from room temperature to 7 K were measured by the three-point bending tests using specimens cut from a melt-processed Dy-Ba-Cu-O bulk superconductor. They were tested in a helium gas flow type cryostat at Forschungszentrum Karlsruhe and in a liquid nitrogen bath at Iwate University. The Young's modulus was calculated by either the slope of stress-strain curve or that of the load-deflection curve of the specimen. Although the bending strength measured in the two institutes coincided well, there was a significant discrepancy in the Young's modulus. The Young's modulus and bending strength increased with decrease of temperature down to 7 K. The amount of increase in the Young's modulus and the bending strength were about 32% and 36% of those at room temperature, respectively. The scatter of data for each run was significant and did not depend on temperature. The temperature dependence of the Young's modulus coincided with that in Y-Ba-Cu-O obtained by ultrasonic velocity. The temperature dependence of the Young's modulus and the bending strength was discussed from the view point of interatomic distance of the bulk crystal

  5. Is point of care testing in Irish hospitals ready for the laboratory modernisation process? An audit against the current national Irish guidelines.

    LENUS (Irish Health Repository)

    O'Kelly, R A

    2013-04-11

    BACKGROUND: The Laboratory modernisation process in Ireland will include point of care testing (POCT) as one of its central tenets. However, a previous baseline survey showed that POCT was under-resourced particularly with respect to information technology (IT) and staffing. AIMS: An audit was undertaken to see if POCT services had improved since the publication of National Guidelines and if such services were ready for the major changes in laboratory medicine as envisaged by the Health Service Executive. METHODS: The 15 recommendations of the 2007 Guidelines were used as a template for a questionnaire, which was distributed by the Irish External Quality Assessment Scheme. RESULTS: Thirty-nine of a possible 45 acute hospitals replied. Only a quarter of respondent hospitals had POCT committees, however, allocation of staff to POCT had doubled since the first baseline survey. Poor IT infrastructure, the use of unapproved devices, and low levels of adverse incident reporting were still major issues. CONCLUSIONS: Point of care testing remains under-resourced, despite the roll out of such devices throughout the health service including primary care. The present high standards of laboratory medicine may not be maintained if the quality and cost-effectiveness of POCT is not controlled. Adherence to national Guidelines and adequate resourcing is essential to ensure patient safety.

  6. An automated and robust image processing algorithm for glaucoma diagnosis from fundus images using novel blood vessel tracking and bend point detection.

    Science.gov (United States)

    M, Soorya; Issac, Ashish; Dutta, Malay Kishore

    2018-02-01

    Glaucoma is an ocular disease which can cause irreversible blindness. The disease is currently identified using specialized equipment operated by optometrists manually. The proposed work aims to provide an efficient imaging solution which can help in automating the process of Glaucoma diagnosis using computer vision techniques from digital fundus images. The proposed method segments the optic disc using a geometrical feature based strategic framework which improves the detection accuracy and makes the algorithm invariant to illumination and noise. Corner thresholding and point contour joining based novel methods are proposed to construct smooth contours of Optic Disc. Based on a clinical approach as used by ophthalmologist, the proposed algorithm tracks blood vessels inside the disc region and identifies the points at which first vessel bend from the optic disc boundary and connects them to obtain the contours of Optic Cup. The proposed method has been compared with the ground truth marked by the medical experts and the similarity parameters, used to determine the performance of the proposed method, have yield a high similarity of segmentation. The proposed method has achieved a macro-averaged f-score of 0.9485 and accuracy of 97.01% in correctly classifying fundus images. The proposed method is clinically significant and can be used for Glaucoma screening over a large population which will work in a real time. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Exfoliating and Dispersing Few-Layered Graphene in Low-Boiling-Point Organic Solvents towards Solution-Processed Optoelectronic Device Applications.

    Science.gov (United States)

    Zhang, Lu; Miao, Zhongshuo; Hao, Zhen; Liu, Jun

    2016-05-06

    With normal organic surfactants, graphene can only be dispersed in water and cannot be dispersed in low-boiling-point organic solvents, which hampers its application in solution-processed organic optoelectronic devices. Herein, we report the exfoliation of graphite into graphene in low-boiling-point organic solvents, for example, methanol and acetone, by using edge-carboxylated graphene quantum dots (ECGQD) as the surfactant. The great capability of ECGQD for graphene dispersion is due to its ultralarge π-conjugated unit that allows tight adhesion on the graphene surface through strong π-π interactions, its edge-carboxylated structure that diminishes the steric effects of the oxygen-containing functional groups on the basal plane of ECGQD, and its abundance of carboxylic acid groups for solubility. The graphene dispersion in methanol enables the application of graphene:ECGQD as a cathode interlayer in polymer solar cells (PSCs). Moreover, the PSC device performance of graphene:ECGQD is better than that of Ca, the state-of-the-art cathode interlayer material. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. [Design of a Hazard Analysis and Critical Control Points (HACCP) plan to assure the safety of a bologna product produced by a meat processing plant].

    Science.gov (United States)

    Bou Rached, Lizet; Ascanio, Norelis; Hernández, Pilar

    2004-03-01

    The Hazard Analysis and Critical Control Point (HACCP) is a systematic integral program used to identify and estimate the hazards (microbiological, chemical and physical) and the risks generated during the primary production, processing, storage, distribution, expense and consumption of foods. To establish a program of HACCP has advantages, being some of them: to emphasize more in the prevention than in the detection, to diminish the costs, to minimize the risk of manufacturing faulty products, to allow bigger trust to the management, to strengthen the national and international competitiveness, among others. The present work is a proposal based on the design of an HACCP program to guarantee the safety of the Bologna Special Type elaborated by a meat products industry, through the determination of hazards (microbiological, chemical or physical), the identification of critical control points (CCP), the establishment of critical limits, plan corrective actions and the establishment of documentation and verification procedures. The used methodology was based in the application of the seven basic principles settled down by the Codex Alimentarius, obtaining the design of this program. In view of the fact that recently the meat products are linked with pathogens like E. coli O157:H7 and Listeria monocytogenes, these were contemplated as microbiological hazard for the establishment of the HACCP plan whose application will guarantee the obtaining of a safe product.

  9. Co-ordination of federal and provincial environmental assessment processes for the Point Lepreau Generating Station Solid Radioactive Waste Management Facility modifications

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, C.; Thompson, P.D. [Point Lepreau Generating Station, Point Lepreau Refurbishment Project, Lepreau, New Brunswick (Canada); Barnes, J. [Jacques Whitford Environment Ltd., Fredericton, New Brunswick (Canada)

    2006-07-01

    Modification of the Solid Radioactive Waste Management Facility at Point Lepreau Generating Station is required to accommodate waste generated during and after an 18-month maintenance outage during which the station would be Refurbished. The modification of the facility triggered both federal and provincial environmental assessment requirements, and these assessments were conducted in a 'coordinated' and cooperative fashion. In this project, the coordinated approach worked well, and provided some significant advantages to the proponent, the public and the regulators. However, there are opportunities for further improvement in future projects, and this paper explores the advantages and disadvantages of this 'co-ordinated' approach. As part of this exploration, there is a discussion of administrative and regulatory changes that the province is considering for the environmental assessment process, and a discussion of the need for a formal 'harmonization' agreement. (author)

  10. Co-ordination of federal and provincial environmental assessment processes for the Point Lepreau Generating Station Solid Radioactive Waste Management Facility modifications

    International Nuclear Information System (INIS)

    Hickman, C.; Thompson, P.D.; Barnes, J.

    2006-01-01

    Modification of the Solid Radioactive Waste Management Facility at Point Lepreau Generating Station is required to accommodate waste generated during and after an 18-month maintenance outage during which the station would be Refurbished. The modification of the facility triggered both federal and provincial environmental assessment requirements, and these assessments were conducted in a 'coordinated' and cooperative fashion. In this project, the coordinated approach worked well, and provided some significant advantages to the proponent, the public and the regulators. However, there are opportunities for further improvement in future projects, and this paper explores the advantages and disadvantages of this 'co-ordinated' approach. As part of this exploration, there is a discussion of administrative and regulatory changes that the province is considering for the environmental assessment process, and a discussion of the need for a formal 'harmonization' agreement. (author)

  11. Assessment of attenuation processes in a chlorinated ethene plume by use of stream bed Passive Flux Meters, streambed Point Velocity Probes and contaminant mass balances

    DEFF Research Database (Denmark)

    Rønde, Vinni Kampman; McKnight, Ursula S.; Annable, Michael

    , however studies contradicting this have also been reported. Since dilution commonly reduces contaminant concentrations in streams to below quantification limits, use of mass balances along the pathway from groundwater to stream is unusual. Our study is conducted at the low-land Grindsted stream, Denmark......Chlorinated ethenes (CE) are abundant groundwater contaminants and pose risk to both groundwater and surface water bodies, as plumes can migrate through aquifers to streams. After release to the environment, CE may undergo attenuation. The hyporheic zone is believed to enhance CE attenuation......, which is impacted by a contaminant plume. CE have been observed in the stream water; hence our study site provides an unusual opportunity to study attenuation processes in a CE plume as it migrates through the groundwater at the stream bank, through the stream bed and further to the point of fully mixed...

  12. Determinantes de la equidad en el financiamiento de los medicamentos en Argentina: un estudio empírico

    OpenAIRE

    Dondo, Mariana; Monsalvo, Mauricio; Garibaldi, Lucas A.

    2016-01-01

    Resumen Los medicamentos constituyen un alto porcentaje del gasto en salud de los hogares, por eso, tener un sistema progresivo de financiamiento de medicamentos es fundamental para lograr un sistema de salud equitativo. Se ha propuesto que los determinantes de la equidad en el financiamiento son socioeconómicos, demográficos y asociados a la intervención pública, sin embargo, se ha avanzado poco en su evaluación empírica y en la cuantificación de su importancia relativa. En este trabajo esti...

  13. Determinantes del retraso de la interrupción voluntaria del embarazo Determinants of induced abortion delay

    OpenAIRE

    Laia Font-Ribera; Glòria Pérez; Albert Espelt; Joaquin Salvador; Carme Borrell

    2009-01-01

    Antecedentes: El momento de la gestación en que se induce una interrupción voluntaria del embarazo (IVE) determina el método, el riesgo de complicaciones y el coste económico de la intervención. El objetivo de nuestro estudio fue describir los determinantes del retraso de la IVE hasta el segundo trimestre de gestación en Barcelona. Métodos: Estudio transversal de las IVE por motivos de salud física o mental de la mujer (Barcelona, 2004-2005; N=9.175). El registro de IVE de la ciudad proporcio...

  14. La repetición máxima en el ejercicio de sentadilla: procedimientos de medida y factores determinantes

    OpenAIRE

    Inmaculada García Sánchez; Bernardo Requena Sánchez

    2011-01-01

    En la actualidad, investigadores y entrenadores utilizan la repetición máxima (1RM) en el ejercicio de sentadilla como la medida más identificativa y representativa de la máxima fuerza muscular en el movimiento de extensión de cadera y rodilla. El presente trabajo de revisión tiene el propósito de describir los procedimientos utilizados en investigación para evaluar la 1RM en el ejercicio de sentadilla y analizar los factores determinantes de su rendimiento. Con muestras de sujetos entrenados...

  15. Determinantes del uso del marketing OnLine en las empresas hoteleras de la ciudad de Puno, 2012

    OpenAIRE

    Cusi Montesinos, Marlene

    2014-01-01

    El trabajo de investigación se realizó con el objetivo de establecer las variables determinantes que permiten explicar el uso del marketing online y la situación de los otros sistemas de articulación comercial en las empresas hoteleras de la ciudad de Puno. La investigación es de tipo explicativa, de diseño no experimental, de corte transversal, con un tamaño de muestra probabilística de 62 empresas hoteleras, y en el que se hizo uso de técnicas de análisis multivariado en la cual se combinó ...

  16. Determinantes sociales de la mortalidad infantil en municipios de bajo índice de desarrollo humano en México

    OpenAIRE

    Duarte-Gómez, María Beatriz; Núñez-Urquiza, Rosa María; Restrepo-Restrepo, José Alonso; Richardson-López-Collada, Vesta Louise

    2015-01-01

    Introducción: Se realizó un estudio con el objetivo de identificar determinantes sociales de mortalidad infantil en zonas rurales en México, y recomendar estrategias para disminuir esta mortalidad. Métodos: Se tomó una muestra por conveniencia de 16 municipios de bajo índice de desarrollo humano. Se identificaron fallecimientos de menores de un año de edad a través de registros oficiales y de entrevistas con autoridades civiles, personal de salud y líderes comunitarios. También se realizar...

  17. Los determinantes de la percepción de inseguridad frente al delito en México

    OpenAIRE

    Vilalta, Carlos J.

    2012-01-01

    ¿Qué determina la sensación de inseguridad frente al delito y qué podemos hacer al respecto? En este estudio se propone y pone a prueba un modelo correlacional que combina diferentes determinantes teóricos de la inseguridad y el miedo al crimen. La prueba se realiza en México y en dos ámbitos espaciales diferentes: el ámbito nacional y el ámbito del Área Metropolitana de la Ciudad de México. Las fuentes de información son la Encuesta Nacional de Victimización y Percepción sobre Seguridad Públ...

  18. Os determinantes da atuação dos intelectuais do trabalho no capitalismo contemporâneo

    OpenAIRE

    SILVA, Eliana Andrade da

    2008-01-01

    Este estudo discute os determinantes da atuação dos intelectuais do trabalho no capitalismo contemporaneo, a partir da realidade dos projetos de assentamento de reforma grária do Rio Grande do Norte. O desvendamento deste objeto teve como caminho metodológico a análise das principais transformações que ocorrem no âmbito do Mercado, do Estado e da Sociedade Civil na atualidade. Dessa forma, partimos do pressuposto que as transformações do capital tem forjado determinações par...

  19. Determinantes sociales de la mortalidad infantil en municipios de bajo índice de desarrollo humano en México

    OpenAIRE

    Duarte-Gómez, María Beatriz; Núñez-Urquiza, Rosa María; Restrepo-Restrepo, José Alonso; López-Collada, Vesta Louise Richardson

    2015-01-01

    ResumenINTRODUCCIÓN: Se realizó un estudio con el objetivo de identificar determinantes sociales de mortalidad infantil en zonas rurales en México, y recomendar estrategias para disminuir esta mortalidad.MÉTODOS: Se tomó una muestra por conveniencia de 16 municipios de bajo índice de desarrollo humano. Se identificaron fallecimientos de menores de un año de edad a través de registros oficiales y de entrevistas con autoridades civiles, personal de salud y líderes comunitarios. También se reali...

  20. Factores determinantes del rendimiento en el ejercicio de dominadas y efectos del entrenamiento concurrente de fuerza y resistencia

    OpenAIRE

    Sánchez Moreno, Miguel

    2017-01-01

    Programa de Doctorado en Actividad Física, Rendimiento Deportivo y Salud En la presente Tesis Doctoral se abordan una serie de problemáticas relacionadas, por una parte, con la mejora del entendimiento sobre aquellos factores que pueden ser determinante para el rendimiento en el ejercicio de dominadas y por otra parte, sobre cuestiones relacionadas con la influencia que puede tener la realización de dos grados de esfuerzo durante el entrenamiento de fuerza del miembro inferior sobre el re...

  1. El capital humano como factor determinante de la absorción de conocimiento en la industria farmacéutica mexicana

    Directory of Open Access Journals (Sweden)

    Herlinda Canto Valencia

    2016-03-01

    Full Text Available La capacidad de absorción, entendida como la apropiación de conocimiento externo para mejorar la innovación de las empresas cuando los determinantes internos son favorables, ha cobrado interés en la última década a nivel mundial. El objetivo de la investigación cuantitativa no experimental, transversal, correlacional-causal es evaluar la relación existente entre la capacidad de absorción potencial del conocimiento externo en sus dos dimensiones: adquirida y asimilada, con el capital humano, que es un determinante que la empresa posee. Llegando a la conclusión de que existe una relación positiva y significativa entre el determinante interno capital humano y la capacidad de absorción potencial.

  2. Assessment of attenuation processes in a chlorinated ethene plume by use of stream bed Passive Flux Meters, streambed Point Velocity Probes and contaminant mass balances

    Science.gov (United States)

    Rønde, V.; McKnight, U. S.; Annable, M. D.; Devlin, J. F.; Cremeans, M.; Sonne, A. T.; Bjerg, P. L.

    2017-12-01

    Chlorinated ethenes (CE) are abundant groundwater contaminants and pose risk to both groundwater and surface water bodies, as plumes can migrate through aquifers to streams. After release to the environment, CE may undergo attenuation. The hyporheic zone is believed to enhance CE attenuation, however studies contradicting this have also been reported. Since dilution commonly reduces contaminant concentrations in streams to below quantification limits, use of mass balances along the pathway from groundwater to stream is unusual. Our study is conducted at the low-land Grindsted stream, Denmark, which is impacted by a contaminant plume. CE have been observed in the stream water; hence our study site provides an unusual opportunity to study attenuation processes in a CE plume as it migrates through the groundwater at the stream bank, through the stream bed and further to the point of fully mixed conditions in the stream. The study undertook the determination of redox conditions and CE distribution from bank to stream; streambed contaminant flux estimation using streambed Passive Flux Meters (sPFM); and quantification of streambed water fluxes using temperature profiling and streambed Point Velocity Probes (SBPVP). The advantage of the sPFM is that it directly measures the contaminant flux without the need for water samples, while the advantage of the SBPVP is its ability to measure the vertical seepage velocity without the need for additional geological parameters. Finally, a mass balance assessment along the plume pathway was conducted to account for any losses or accumulations. The results show consistencies in spatial patterns between redox conditions and extent of dechlorination; between contaminant fluxes from sPFM and concentrations from water samples; and between seepage velocities from SBPVP and temperature-based water fluxes. Mass balances and parent-metabolite compound ratios indicate limited degradation between the bank and the point of fully mixed stream

  3. [Eight-step structured decision-making process to assign criminal responsibility and seven focal points for describing relationship between psychopathology and offense].

    Science.gov (United States)

    Okada, Takayuki

    2013-01-01

    The author suggested that it is essential for lawyers and psychiatrists to have a common understanding of the mutual division of roles between them when determining criminal responsibility (CR) and, for this purpose, proposed an 8-step structured CR decision-making process. The 8 steps are: (1) gathering of information related to mental function and condition, (2) recognition of mental function and condition,(3) psychiatric diagnosis, (4) description of the relationship between psychiatric symptom or psychopathology and index offense, (5) focus on capacities of differentiation between right and wrong and behavioral control, (6) specification of elements of cognitive/volitional prong in legal context, (7) legal evaluation of degree of cognitive/volitional prong, and (8) final interpretation of CR as a legal conclusion. The author suggested that the CR decision-making process should proceed not in a step-like pattern from (1) to (2) to (3) to (8), but in a step-like pattern from (1) to (2) to (4) to (5) to (6) to (7) to (8), and that not steps after (5), which require the interpretation or the application of section 39 of the Penal Code, but Step (4), must be the core of psychiatric expert evidence. When explaining the relationship between the mental disorder and offense described in Step (4), the Seven Focal Points (7FP) are often used. The author urged basic precautions to prevent the misuse of 7FP, which are: (a) the priority of each item is not equal and the relative importance differs from case to case; (b) each item is not exclusively independent, there may be overlap between items; (c) the criminal responsibility shall not be judged because one item is applicable or because a number of items are applicable, i. e., 7FP are not "criteria," for example, the aim is not to decide such things as 'the motive is understandable' or 'the conduct is appropriate', but should be to describe how psychopathological factors affected the offense specifically in the context of

  4. Determinantes de la participación laboral femenina en Venezuela: Aplicación de un modelo probit para el año 2005

    OpenAIRE

    Martínez, Ángel

    2010-01-01

    La participación laboral de la mujer es un tema de análisis en muchos estudios a nivel mundial, cuyo objetivo es presentar un panorama acerca de la igualdad de género en el empleo. La oferta y la demanda en el mercado de trabajo es el resultado de la interacción de variables principalmente sociales y económicas que se encuentran interconectadas. Este trabajo realiza un análisis conjunto de los determinantes de la participación laboral femenina en Venezuela. También analiza los determinantes d...

  5. Propuesta de abordaje sobre determinantes sociales de la salud y cambio climático en comunidades dependientes de los desechos sólidos en Managua, Nicaragua

    OpenAIRE

    Paredes Gaitán, Yolanda; Martín, Miguel; Universitat Autònoma de Barcelona. Departament de Pediatria, d'Obstetrícia i Ginecologia i de Medicina Preventiva

    2014-01-01

    OBJETIVOS: Esta investigación elabora una propuesta de abordaje sobre los determinantes sociales de la salud y el cambio climático en una comunidad dependiente de los desechos sólidos en la ciudad de Managua, Nicaragua. Partiendo del análisis social y económico, tanto del país como de la comunidad en estudio, se plantean acciones sociales y económicas basadas en los determinantes sociales que inciden en la salud. DESCRIPCIÓN: Con base en el análisis social y económico hecho a la población dep...

  6. Determinantes sociales y estado de la dentición en escolares de San Felipe del Progreso, estado de México

    OpenAIRE

    Eveline Contreras Huerta; Cristina Sifuentes Valenzuela; Javier de la Fuente-Hernández; Laura Susana Acosta-Torres; María del Carmen Villanueva Vilchis

    2015-01-01

    Los determinantes sociales son aquellas condiciones sociales de desarrollo que impactan la salud. Existe asociación entre algunos problemas bucales con una inequitativa distribución económica. Objetivo : Identificar la asocia - ción entre algunos determinantes sociales y la experiencia de caries en niños de San Felipe del Progreso. Metodología: Estudio transversal. Se seleccionaron 83 niños de 6 a 12 años y se les aplicó un cuestionario socio-demográfico. Se evaluó la experiencia de carie...

  7. Reações adversas a medicamentos como determinantes da admissão hospitalar

    Directory of Open Access Journals (Sweden)

    PFAFFENBACH GRACE

    2002-01-01

    Full Text Available OBJETIVO: A freqüência de reação adversa a medicamentos (RAM como determinante da hospitalização não está bem documentada na literatura médica brasileira. Objetivou-se determinar esta freqüência, documentando o padrão de uso de medicamentos antes da hospitalização. MÉTODOS: O estudo foi realizado em um hospital escola de atenção terciária à saúde. Constou de duas fases distintas, sendo a primeira a análise dos dados disponíveis a respeito dos diagnósticos que levaram à admissão hospitalar na enfermaria de Medicina Interna durante o ano de 1997. Após esta análise, foi realizado em 1999 o monitoramento intensivo das RAMs de pacientes internados durante quatro meses e o registro dos medicamentos usados nos 15 dias que antecederam a internação e os padrões de morbidade dos pacientes da enfermaria. RESULTADOS: Em 1997, ocorreram 938 internações, 53,4% de pacientes masculinos, com 1,1 diagnóstico por internação e nenhum diagnóstico de RAM. Na segunda fase do estudo, dos 135 pacientes, 52% do sexo feminino, 92% usaram medicamentos antes da internação, e destes, 42% se auto-medicaram nos 15 dias anteriores à internação. A média de uso de medicamentos foi de 3,7. RAM foi responsável por ou teve participação em 6,6% das internações. CONCLUSÕES: O Monitoramento intensivo de pacientes estimula a notificação de RAM e serve como um recurso didático importante na formação dos profissionais de saúde quanto ao uso racional de medicamentos.

  8. Factores determinantes del rendimiento en vela deportiva: revisión de la literatura

    Directory of Open Access Journals (Sweden)

    Aarón Manzanares Serrano

    2012-01-01

    Full Text Available Los objetivos del presente estudio han sido revisar, identificar y analizar las investigaciones que han indagado acerca de los factores influyentes en el rendimiento deportivo en vela y determinar cuáles de éstos son los de mayor relevancia. Se presentan los datos obtenidos a partir del análisis realizado sobre diez bases de datos, empleando como descriptores de búsqueda de artículos científicos las palabras "sail", "sailing" y "sailor". Se acotó la búsqueda a los trabajos que contenían dichas palabras clave en el título o el abstract, restringiendo la pesquisa al periodo comprendido entre 1950 y 2011. Los artículos analizados en esta revisión han sido todos los referentes a las características físicas, tácticas, técnicas, psicológicas y de toma de decisiones de los regatistas, que influirían directamente en el rendimiento. De los artículos analizados en el presente estudio, el 54% se refieren a características físicas, siendo éste el factor de rendimiento más estudiado, seguido de la técnica con un 22% y de la toma de decisiones con el 14%. La táctica (5% y la psicología (3% son los dos aspectos menos investigados. Como conclusión, se considera que los regatistas de cada clase de navegación requieren unas características físicas y/o fisiológicas diferentes. Dentro de la vela deportiva existen diferentes tipos de embarcaciones, que requieren diversos esfuerzos por parte del regatista, cuestión que obliga al conocimiento de sus características físicas y fisiológicas de manera específica para cada clase de embarcación. Además de las diferencias en las capacidades físicas condicionales requeridas en cada clase, otros factores determinantes para el rendimiento en este deporte como son la capacidad de percepción de estímulos y la toma de decisiones, son consideradas en menor medida en los estudios analizados.

  9. FATORES SOCIOAMBIENT AIS DETERMINANTES DE PARASITOSES INTESTINAIS NA LOCALIDADE HOMERO FIGUEIREDO, FEIRA DE SANTANA, BAHIA, BRASIL.

    Directory of Open Access Journals (Sweden)

    Alany Santos Oliveira

    2015-01-01

    Full Text Available As parasitoses intestinais são doenças cujos agentes etiológicos são helmintos ou protozoários,que se apresentam de forma endêmica em diversas áreas do Brasil, constituindo-se em um dosprincipais problemas de saúde pública, devido ao difícil acesso ao saneamento básico e àeducação pela população mais carente, já que a transmissão desses agentes está diretamenterelacionada com as condições de vida e de higiene da população. O presente trabalho teve comoobjetivo identificar os fatores socioambientais determinantes na disseminação de helmintos eprotozoários entre os indivíduos da localidade Homero Figueiredo, Feira de Santana - BA, localque possui abastecimento de água e esgotamento sanitário. Para isso, foram aplicadosformulários individuais e familiares, a fim de verificar os aspectos epidemiológicos dapopulação em estudo. Além disso, foi realizado o parasitológico de fezes da população, parapesquisa de helmintos e protozoários. A partir dos resultados obtidos no inquérito realizado edas análises parasitológicas, pôde-se constatar que houve positividade em relação às parasitosesintestinais, apesar da presença de condições mínimas de saneamento, como abastecimento deágua e coleta e tratamento de esgoto, e que alguns hábitos podem implicar em riscos decontaminação por parasitos. Diante do exposto, conclui-se que o índice de parasitos e comensaisintestinais em uma localidade está associado a fatores culturais e econômicos, bem como ascondições ambientais presentes no local de habitação e convívio social. Há de se considerar que,além da melhoria das condições sócio-econômicas e da infraestrutura geral, é necessário,também, o engajamento comunitário que é um dos aspectos fundamentais para implantação,desenvolvimento e sucesso dos programas de controle.

  10. β-Decay half-lives and nuclear structure of exotic proton-rich waiting point nuclei under rp-process conditions

    Science.gov (United States)

    Nabi, Jameel-Un; Böyükata, Mahmut

    2016-03-01

    We investigate even-even nuclei in the A ∼ 70 mass region within the framework of the proton-neutron quasi-particle random phase approximation (pn-QRPA) and the interacting boson model-1 (IBM-1). Our work includes calculation of the energy spectra and the potential energy surfaces V (β , γ) of Zn, Ge, Se, Kr and Sr nuclei with the same proton and neutron number, N = Z. The parametrization of the IBM-1 Hamiltonian was performed for the calculation of the energy levels in the ground state bands. Geometric shape of the nuclei was predicted by plotting the potential energy surfaces V (β , γ) obtained from the IBM-1 Hamiltonian in the classical limit. The pn-QRPA model was later used to compute half-lives of the neutron-deficient nuclei which were found to be in very good agreement with the measured ones. The pn-QRPA model was also used to calculate the Gamow-Teller strength distributions and was found to be in decent agreement with the measured data. We further calculate the electron capture and positron decay rates for these N = Z waiting point (WP) nuclei in the stellar environment employing the pn-QRPA model. For the rp-process conditions, our total weak rates are within a factor two compared with the Skyrme HF +BCS +QRPA calculation. All calculated electron capture rates are comparable to the competing positron decay rates under rp-process conditions. Our study confirms the finding that electron capture rates form an integral part of the weak rates under rp-process conditions and should not be neglected in the nuclear network calculations.

  11. Determinantes espaciais e socioeconômicos do suicídio no Brasil: uma abordagem regional

    Directory of Open Access Journals (Sweden)

    Ludmilla R. C. Gonçalves

    2012-01-01

    Full Text Available A Organização Mundial da Saúde avalia o suicídio como um problema de saúde pública, estando entre as dez causas mais frequentes de morte, além de ser a segunda ou terceira causa de morte entre 15 e 34 anos de idade. Estimativas mostram que para cada suicídio, existem pelo menos dez tentativas suficientemente sérias que exigem atenção médica e para cada tentativa de suicídio registrada, existem quatro não conhecidas. O objetivo desse artigo é avaliar os determinantes socioeconômicos das taxas de suicídio por microrregiões brasileiras, levando em consideração aspectos espaciais do problema. A hipótese desse artigo é que existe um “efeito contágio” espacial para o suicídio, ou seja, as taxas de suicídio dos vizinhos de uma microrregião são importantes determinantes do comportamento dessa variável em outra microrregião. Para tal, são usadas técnicas de econometria espacial que permitem avaliar se existe dependência espacial entre as taxas de suicídio das microrregiões.

  12. Epidemiología y determinantes sociales asociados a la obesidad y la diabetes tipo 2 en México

    Directory of Open Access Journals (Sweden)

    L. Moreno-Altamirano

    2014-07-01

    Full Text Available La diabetes y la obesidad como problemas de salud pública en México son analizados a la luz de su magnitud y distribución en el contexto de algunos de sus determinantes sociales: alimentación, sedentarismo y distribución del ingreso. Se presentan aspectos generales sobre estas enfermedades y su comportamiento epidemiológico en México. Se revisa el papel de la alimentación como determinante social fundamental para la presencia de la diabetes tipo 2 y obesidad. Asimismo, se argumenta sobre la importancia de la actividad física para su prevención y control. Se destaca el papel de la distribución de grasa corporal y la obesidad como producto de la transición alimentaria. Finalmente se expresan algunas recomendaciones que podrían contribuir a fortalecer las estrategias propuestas para disminuir su frecuencia, la mortalidad y las complicaciones de estas enfermedades.

  13. Determinantes do aborto provocado entre mulheres admitidas em hospitais em localidade da região Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Walter Fonseca

    1996-02-01

    Full Text Available Com o objetivo de identificar os determinantes do aborto provocado entre mulheres admitidas por complicações decorrentes dos abortos, nos hospitais-maternidades públicos em Fortaleza, CE (Brasil foram entrevistadas 4.359 pacientes entre 1º de outubro de 1992 e 30 de setembro de 1993. Os dados foram coletados através de questionário estruturado. São apresentados os determinantes dos abortos provocados em 2.084 (48% mulheres classificadas como tendo induzido aborto. Dois terços (66% das mulheres relataram a indução do aborto com o uso isolado do Cytotec(R (misoprostol ou associado a outro meio abortivo. Os resultados indicam que, na população estudada, a indução do aborto é prática comum entre jovens, solteiras (ou que vivem sem um parceiro estável, de baixa paridade, com escolaridade incipiente e não-usuárias de métodos contraceptivos. Recomenda-se a realização de estudos que investiguem os conhecimentos relacionados a percepções, conceitos culturais do aborto, e às razões por que mulheres pobres fracassam na adoção de métodos de planejamento familiar.

  14. Determinantes do aborto provocado entre mulheres admitidas em hospitais em localidade da região Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Fonseca Walter

    1996-01-01

    Full Text Available Com o objetivo de identificar os determinantes do aborto provocado entre mulheres admitidas por complicações decorrentes dos abortos, nos hospitais-maternidades públicos em Fortaleza, CE (Brasil foram entrevistadas 4.359 pacientes entre 1º de outubro de 1992 e 30 de setembro de 1993. Os dados foram coletados através de questionário estruturado. São apresentados os determinantes dos abortos provocados em 2.084 (48% mulheres classificadas como tendo induzido aborto. Dois terços (66% das mulheres relataram a indução do aborto com o uso isolado do Cytotec(R (misoprostol ou associado a outro meio abortivo. Os resultados indicam que, na população estudada, a indução do aborto é prática comum entre jovens, solteiras (ou que vivem sem um parceiro estável, de baixa paridade, com escolaridade incipiente e não-usuárias de métodos contraceptivos. Recomenda-se a realização de estudos que investiguem os conhecimentos relacionados a percepções, conceitos culturais do aborto, e às razões por que mulheres pobres fracassam na adoção de métodos de planejamento familiar.

  15. DETERMINANTES DA DIVULGAÇÃO DOS INDICADORES DE DESEMPENHO DA GRI NAS EMPRESAS DO BRASIL E DA ESPANHA

    Directory of Open Access Journals (Sweden)

    Alan Diógenes Góis

    2015-01-01

    Full Text Available O estudo tem por objetivo investigar os fatores determinantes da divulgação dos indicadores de desempenho de sustentabilidade da GRI nas empresas listadas nas bolsas do Brasil e da Espanha. Para tanto, foram analisados os dados de 94 empresas de capital aberto dos dois países que publicaram relatórios anuais e/ou de sustentabilidade, referentes a 2011, no padrão GRI-G3. A pesquisa é descritiva, com abordagem quantitativa dos dados, utilizando-se a Regressão Linear Múltipla para quatro modelos de disclosure (econômico, ambiental, social e de sustentabilidade. Os resultados mostram que as empresas da Espanha apresentam um nível de disclosure de sustentabilidade mais elevado, e que o nível de evidenciação geral, considerando o conjunto das dimensões da sustentabilidade (econômica, social e ambiental, corresponde a 72,7%. Quanto ao resultado dos modelos de regressão, observa-se que as variáveis independentes (Tamanho, Rentabilidade, Endividamento, Auditoria, Setor de Impacto Ambiental e Idade não explicam o disclosure econômico; porém, quanto aos disclosures ambiental, social e de sustentabilidade, as variáveis Tamanho e Idade são fatores determinantes.

  16. Contamination and Critical Control Points (CCPs along the processing line of sale of frozen poultry foods in retail outlets of a typical market in Ibadan, Nigeria

    Directory of Open Access Journals (Sweden)

    Adetunji, V. O

    2013-12-01

    Full Text Available Aim: Over the years, there have been considerable increases in the consumption of frozen poultry foods across Nigeria. Little attention has been paid to the microbial quality of these foods and hence constitutes a threat to public health. The contamination levels (Enterobacteriaceae and Listeria counts and the presence of pathogenic E. coli, Salmonella and Listeria along the processing line of sale of frozen poultry foods were assayed in retail outlets. Methodology and results: Bacteriological counts and bacterial isolation were carried out using standard plate methods, while the direct slide agglutination technique was utilized for serology. Bacteriological assay revealed extremely high counts (Listeria count (LC: 7.784±1.109 - 9.586±0.016 log cfu/cm2; Enterobacteriaceae count (EC: 7.151±0.213 - 9.318±0.161 log cfu/cm2, higher than stipulated by International Food Standard Agencies. The highest count for EC (9.318±0.161 log cfu/cm2 and LC 9.586±0.016 log cfu/cm2 was from the weighing scale and processing table. Averagely, LC (8.598±0.733 log cfu/cm2 was higher than EC (8.145±0.936 log cfu/cm2. Weighing scale had counts significantly different (p < 0.05 from all others for EC. But there were no significant differences in LC. Weighing scale and meat tables were critical control points (CCPs in the processing line for sale of frozen poultry meats in the retail outlets. E. coli spp., E. coli O157:H7, Salmonella spp., Salmonella Enteritidis, Listeria spp. and Listeria monocytogenes were isolated along the processing line. Conclusion, significance and impact of the study: Results of this study indicated that poultry meat are easily contaminated along the processing line of sale and may act as a potential risk to public health if counteractive measures are not applied to reduce microbial contamination during storage, sale and distribution to consumers.

  17. ANÁLISIS DEL RIESGO DE INCENDIOS FORESTALES: UN ENFOQUE BASADO EN PROCESOS PUNTUALES // FOREST WILDFIRE HAZARD ANALYSES: A POINT PROCESSES APPROACH

    Directory of Open Access Journals (Sweden)

    Rafael González de Gouveia

    2017-06-01

    Full Text Available Los procesos estocásticos puntuales representan una herramienta de gran utilidad para el análisis de los factores de riesgo en los incendios forestales. En este artículo se estudia la ocurrencia de los incendios forestales a partir de un proceso de Poisson espacio temporal, en el que se considera la función de intensidad del mismo como una caracterización del riesgo de incendio a partir de técnicas paramétricas y no paramétricas. Finalmente, se considera un conjunto de datos reales, suministrados por el Ministerio del Poder Popular para el Ambiente a través del Instituto Nacional de Meteorología e Hidrología (INAMEH en Venezuela, relativos a los incendios forestales producidos en un día en particular. Se estiman las funciones de riesgo basadas en el modelo propuesto y se generan mapas de riesgo de incendios lo cuales se ajustan a las características geográficas y climáticas del país. // Point stochastic processes represent a very useful tool for the analysis of hazard factors in wildfire. In this article, the occurrence of wildfire is studied from a spatial-temporal Poisson process, in which the intensity function thereof is considered as a wildfire hazard characterization based on parametric and non-parametric techniques. Finally, it is considered a set of real data, provided by the Ministerio del Poder Popular para el Ambiente from Instituto Nacional de Meteorología e Hidrologia (INAMEH of Venezuela, relating to widlfire produced on a particular day. The hazard functions are estimated based on the proposed model and wildfire hazard maps are generated, which are adjusted to the geographical and climatic characteristics of the country.

  18. Modelling point patterns with linear structures

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    2009-01-01

    processes whose realizations contain such linear structures. Such a point process is constructed sequentially by placing one point at a time. The points are placed in such a way that new points are often placed close to previously placed points, and the points form roughly line shaped structures. We...... consider simulations of this model and compare with real data....

  19. Modelling point patterns with linear structures

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    processes whose realizations contain such linear structures. Such a point process is constructed sequentially by placing one point at a time. The points are placed in such a way that new points are often placed close to previously placed points, and the points form roughly line shaped structures. We...... consider simulations of this model and compare with real data....

  20. Neutron-Rich Silver Isotopes Produced by a Chemically Selective Laser Ion-Source: Test of the R-Process " Waiting-Point " Concept

    CERN Multimedia

    2002-01-01

    The r-process is an important nucleosynthesis mechanism for several reasons: \\begin{enumerate} \\item It is crucial to an understanding of about half of the A>60 elemental composition of the Galaxy; \\item It is the mechanism that forms the long-lived Th-U-Pu nuclear chronometers which are used for cosmochronolgy; \\item It provides an important probe for the temperature (T$ _{9} $)-neutron density ($n_{n}$) conditions in explosive events; and last but not least \\item It may serve to provide useful clues to and constraints upon the nuclear properties of very neutron-rich heavy nuclei. \\end{enumerate} \\\\ \\\\With regard to nuclear-physics data, of particular interest are the T$ _{1/2} $ and P$_{n-} $ values of certain$\\,$ "waiting-point"$\\,$ isotopes in the regions of the A $ \\approx $ 80 and 130. r-abundance peaks. Previous studies of $^{130}_{\\phantom{1}48}$Cd$_{82}$ and $^{79}_{29}$Cu$_{50}$. $\\beta$-decay properties at ISOLDE using a hot plasma ion source were strongly complicated by isobar and molecular-ion c...

  1. Site formation processes at Pinnacle Point Cave 13B (Mossel Bay, Western Cape Province, South Africa): resolving stratigraphic and depositional complexities with micromorphology.

    Science.gov (United States)

    Karkanas, Panagiotis; Goldberg, Paul

    2010-01-01

    Site PP13B is a cave located on the steep cliffs of Pinnacle Point near Mossel Bay in Western Cape Province, South Africa. The depositional sequence of the cave, predating Marine Isotopic Stage 11 (MIS 11) and continuing to present, is in the form of isolated sediment exposures with different depositional facies and vertical and lateral variations. Micromorphological analysis demonstrated that a suite of natural sedimentation processes operated during the development of the sequence ranging from water action to aeolian activity, and from speleothem formations to plant colonization and root encrustation. At the same time, anthropogenic sediments that are mainly in the form of burnt remains from combustion features (e.g., wood ash, charcoal, and burnt bone) were accumulating. Several erosional episodes have resulted in a complicated stratigraphy, as discerned from different depositional and post-depositional features. The cave is associated with a fluctuating coastal environment, frequent changes in sea level and climate controlled patterns of sedimentation, and the presence or absence of humans. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Model-based testing for space-time interaction using point processes: An application to psychiatric hospital admissions in an urban area.

    Science.gov (United States)

    Meyer, Sebastian; Warnke, Ingeborg; Rössler, Wulf; Held, Leonhard

    2016-05-01

    Spatio-temporal interaction is inherent to cases of infectious diseases and occurrences of earthquakes, whereas the spread of other events, such as cancer or crime, is less evident. Statistical significance tests of space-time clustering usually assess the correlation between the spatial and temporal (transformed) distances of the events. Although appealing through simplicity, these classical tests do not adjust for the underlying population nor can they account for a distance decay of interaction. We propose to use the framework of an endemic-epidemic point process model to jointly estimate a background event rate explained by seasonal and areal characteristics, as well as a superposed epidemic component representing the hypothesis of interest. We illustrate this new model-based test for space-time interaction by analysing psychiatric inpatient admissions in Zurich, Switzerland (2007-2012). Several socio-economic factors were found to be associated with the admission rate, but there was no evidence of general clustering of the cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Determinantes de la productividad regional del trabajo de la hostelería en España, 1996-2004

    OpenAIRE

    Bienvenido Ortega Aguaza

    2011-01-01

    El propósito de este trabajo es analizar, de forma empírica, cómo los distintos factores determinantes del crecimiento económico han podido condicionar la evolución relativa de la productividad regional del trabajo en España.

  4. Infobarris: una herramienta interactiva para monitorizar y divulgar información sobre la salud y sus determinantes en los barrios de Barcelona

    Directory of Open Access Journals (Sweden)

    Pere Llimona

    2017-09-01

    Full Text Available Para conocer la salud de la población es necesario realizar un análisis conjunto y continuado de su estado de salud y de sus determinantes. El objetivo de esta nota de campo es describir el desarrollo y el funcionamiento de la herramienta Infobarris, que permite visualizar una amplia batería de indicadores y determinantes de la salud de la población de la ciudad de Barcelona según el barrio de residencia. Para el desarrollo de Infobarris se ha usado una metodología ágil que permite el desarrollo de un proyecto de forma iterativa e incremental en etapas: selección de indicadores, diseño del prototipo, desarrollo de la herramienta de visualización, carga de datos, revisión y mejora de la herramienta. Infobarris permite la visualización interactiva de 64 indicadores de salud y de sus determinantes, mediante gráficos, mapas y tablas, lo que facilita la vigilancia de la salud y de sus determinantes en los barrios de la ciudad de Barcelona.

  5. Determinantes sociais da saúde e qualidade de vida de cuidadores de crianças com câncer

    Directory of Open Access Journals (Sweden)

    Rebeca Silveira Rocha

    Full Text Available RESUMO Objetivo Associar os determinantes sociais de saúde e a qualidade de vida de cuidadores de crianças com câncer. Métodos Estudo transversal, realizado em centro pediátrico do câncer, em Fortaleza/CE, com 176 participantes, durante novembro e dezembro/2013. Utilizou-se questionário contendo determinantes sociais de saúde e World Health Quality of Life-Bref para a avaliação da qualidade de vida. Foram correlacionados os determinantes com as médias dos domínios da qualidade de vida, utilizando a análise de variância (ANOVA. Resultados Houve significância estatística na associação entre o domínio das relações sociais e a escolaridade (p=0,01792 e entre o domínio psicossocial e o sexo do cuidador (p=0,01901. Os cuidadores do sexo masculino, nível educacional alto, mais jovens, casados, do lar e procedentes do interior possuem melhor qualidade de vida. Conclusão O estudo permitiu a compreensão da influência dos determinantes sociais de saúde na qualidade de vida de cuidadores de crianças com câncer.

  6. Determinantes sociodemográficos, antropométricos e alimentares de dislipidemia em pré-escolares

    Directory of Open Access Journals (Sweden)

    Luciana N. Nobre

    2013-10-01

    Full Text Available OBJETIVO: O objetivo deste estudo foi investigar os determinantes de dislipidemia em pré-escolares. MÉTODOS: A partir de um desenho transversal, foi avaliado um total de 227 pré-escolares com 5 anos de idade residentes em uma área urbana da cidade de Diamantina, Minas Gerais, Brasil. Foram avaliados: variáveis bioquímicas, antropométricas, condição socioeconômica e comportamental, a partir de um questinário; e ingestão alimentar, a partir de um questionário de fequência de consumo de alimentos. Os padrões alimentares denominados "dieta mista", "fast food" e "não saudável" foram identificados por meio de análise de componentes principais. Os determinantes de dislipidemia foram examinados através da análise de regressão de Poisson. RESULTADOS: A prevalência de dislipidemia, neste estudo, foi de 65,19%. Os pré-escolares que consumiam com menos frequência alimentos do padrão "dieta mista" tiveram um risco maior de concentrações mais altas de lipoproteína de baixa densidade (PR = 2,30; p = 0,004, em comparação com aqueles com um consumo mais frequente do padrão "dieta mista". Os pré-escolares cujas mães apresentaram uma escolaridade mais baixa tiveram menor risco de concentrações mais altas de lipoproteína de baixa densidade (PR = 0,43; p = 0,003, e os pré-escolares que estavam com sobrepeso/obesos apresentaram maior risco de concentrações mais altas de lipoproteína de baixa densidade (PR = 2,23; p = 0,003. CONCLUSÃO: Os determinantes de dislipidemia identificados neste estudo foram o consumo menos frequente de alimentos do padrão "dieta mista", índice de massa corporal mais alto e um maior nível de escolaridade materna. Este estudo mostra que, apesar da baixa idade do grupo em estudo, já estão apresentando alta prevalência de dislipidemia, que é um fator de risco importante para doença cardiovascular.

  7. Determinantes da demanda brasileira por importação de arroz do Mercosul

    Directory of Open Access Journals (Sweden)

    Daniel Henrique Dario Capitani

    2011-09-01

    Full Text Available Desde meados da década de 1990, o arroz é um dos principais produtos agrícolas importados pelo Brasil, principalmente do Uruguai e da Argentina, o que frequentemente gera questionamentos dos orizicultores brasileiros. O objetivo deste artigo é analisar os determinantes das importações brasileiras deste cereal, e para tanto, apresenta-se um modelo econômico visando analisar esta relação comercial no Mercosul, assumindo que as importações brasileiras de arroz são resultantes de um excesso de demanda doméstica pelo cereal. Utiliza-se um Modelo Autorregressivo Vetorial - VAR estrutural. Os resultados mostram uma forte relação do volume importado com o preço doméstico do arroz e com a taxa de câmbio. Verifica-se uma significativa participação do preço de importação na explicação do preço doméstico. A quantidade importada de arroz responde positivamente a um choque positivo no preço doméstico e negativamente a choques positivos no preço de importação e na taxa de câmbio. Verifica-se uma relação de bicausalidade entre o preço doméstico e o preço de importação de arroz. Uma das principais conclusões é que a demanda por importação reage imediatamente a choques no preço doméstico e taxa de câmbio, e posteriormente, a choques no preço de importação, sugerindo dificuldades em substituir imediatamente o volume importado no mercado doméstico.Since the middle of the 90's, rice has been one of the main agricultural products imported by Brazil, particularly from Uruguay and Argentina, which very often raises concerns to Brazilian rice producers. This paper aims to analyze the factors that determine the Brazilian rice imports, and therefore proposes an economic model to examine these trade flows in Mercosur, assuming that the Brazilian rice imports results from a domestic demand surplus. An econometric model Vector Auto-regressive (structural VAR is applied. Results show a strong relationship among rice imports

  8. Determinantes socioeconómicos y demográficos de las actitudes hacia el aborto

    Directory of Open Access Journals (Sweden)

    Cruz García Lirios

    2012-07-01

    hacia el aborto inducido. Para tal propósito, se revisaron los estudios psicológicos y actitudinales relativos a la salud sexual con el fin de construir un instrumento que midió la actitud hacia conductas sexuales de riesgo en una muestra de 300 usuarios de una biblioteca pública. Una vez establecidas la confiabilidad (alfa de .865 para norma y .768 para actitud y la validez del instrumento, se procedió a estimar un modelo de relaciones causales y su ajuste con el modelo teórico. Los resultados muestran que el sexo es el determinante positivo de la norma de grupo (β = -.28 y que el nivel educativo afecta negativamente a la actitud (β = -.90. Tales hallazgos son discutidos en el marco de los programas educativos de orientación.

  9. Examen General de Egreso de Licenciatura Agronómica: Determinantes del Puntaje Examen General de Egreso de Licenciatura Agronómica: Determinantes del Puntaje

    Directory of Open Access Journals (Sweden)

    Mauricio Valencia Posadas

    2012-02-01

    Full Text Available This research determined some factors which had an impact on the scores obtained on the General Bachelor’s Degree Exam (GBDE applied to graduates from the University of Guanajuato. The statistical analysis was performed using a factorial analysis of variance, the Spearman correlation, multiple regression analysis, and Tukey’s range test. Results showed that male students who obtained a grade point average bigger than 8.2 at college and that took the general exam during October 2000, obtained the best test scores. The highest negative correlation was estimated between the grade point average obtained at college and the number of courses failed. According to the regression analysis, the most important variables were the grade point average obtained at college and the year they took the exam. The factors that had the greatest impact on GBDE scores were essentially gender, grade point average obtained at college, the high school attended, and the month and year the exam was taken. El trabajo determinó algunos factores que inciden en el puntaje alcanzado en el Examen General de Egreso de la Licenciatura en Agronomía (EGEL-IA por egresados de la Universidad de Guanajuato. Se empleó un diseño factorial, correlación de Spearman, análisis de regresión múltiple y comparación de medias de Tukey. Los varones con promedio en la carrera mayor a 8.2 y que sustentaron el EGEL–IA durante octubre del 2000 lograron los mayores puntajes. La correlación más alta fue el promedio de carrera con el número de materias reprobadas, mientras que en la regresión fueron el promedio de carrera y el año de examen. Por tanto, el puntaje alcanzado depende del género, el promedio de carrera, la preparatoria de procedencia, el mes y año de presentación del EGEL-IA.

  10. Determinantes da transparência na gestão pública dos municípios portugueses

    OpenAIRE

    Nogueira, Sónia P.; Freitas, Ivone; Ribeiro, Nuno A.

    2017-01-01

    A transparência na gestão pública é fundamental para que exista uma aproximação entre os cidadãos e os gestores públicos, sendo considerada universalmente como um elemento de boa governação. Apesar dos esforços mais recentes, a pesquisa empírica atual ainda não fornece respostas definitivas sobre as razões que justificam as flutuações nos níveis de transparência. O objetivo principal deste estudo consistiu na identificação dos fatores determinantes de transparência na gestão pública dos mu...

  11. La pobreza infantil en clave de derechos humanos y sociales. Definiciones, estimaciones y principales determinantes (2010-2014

    Directory of Open Access Journals (Sweden)

    Ianina Tuñón

    2017-01-01

    Full Text Available Los niños, niñas y adolescentes conforman una de las poblaciones más vulnerables a la pobreza con relativa independencia de la definición y método de medición que se utilice. En este artículo se presentan diferentes formas de medir la pobreza a nivel de la infancia y adolescencia en la Argentina urbana, y se presenta un índice multidimensional que busca dar cuenta de la complejidad del fenómeno. Se definieron espacios de privación relacionados con distintas dimensiones de derecho: alimentación, saneamiento, vivienda, salud, estimulación temprana, educación e información. A partir de los datos de la Encuesta de la Deuda Social Argentina, se analiza la incidencia, evolución y determinantes de las privaciones entre 2010 y 2014.

  12. La crisis de los frutos saludables como factor determinante de la "revolución de los comuneros"

    Directory of Open Access Journals (Sweden)

    Luis Rubén Pérez-Pinzón

    2014-07-01

    Full Text Available El artículo reflexiona acerca de los discursos e imaginarios tradicionales sobre la Revolución de los Comuneros en Colombia y los contrasta con los análisis socioculturales y las descripciones etiopatológicas de dos curas párrocos ilustrados y protomédicos del siglo XVIII en la Nueva Granada con el propósito de demostrar como factores determinantes de la revuelta popular de 1781 las dificultades monopólicas y tributarias para acceder a las yerbas, frutas y bebidas populares consideradas medicinales y saludables, así como fuentes del bienestar ambiental y la prosperidad socioeconómica de los más pobres.

  13. FATORES DETERMINANTES DA TOMADA DE DECISÃO PARA O CONSUMO DE PRODUTOS ORGÂNICOS EM UMA FEIRA LIVRE

    Directory of Open Access Journals (Sweden)

    Ilton Belchior Cruvinel

    2017-06-01

    renda familiar média de 8,3 salários mínimos e que consome produtos orgânicos de três a sete vezes por semana. Os principais fatores determinantes para a tomada de decisão de compra dos produtos orgânicos foram a preocupação com a saúde, com o meio ambiente e com a qualidade dos produtos. Foi possível verificar um interesse crescente do consumidor por alimentação orgânica e, Consequentemente, saudável e sustentável.

  14. La industria minera en México: patrones de desempeño y determinantes de eficiencia

    Directory of Open Access Journals (Sweden)

    Edgar David Gaytán

    2014-01-01

    Full Text Available El propósito del presente artículo es cuantificar y analizar los niveles de eficiencia técnica en la minería no petrolera de México. Se emplea el análisis envolvente de datos (DEA y un modelo econométrico de panel que explora las determinantes de la eficiencia en la operación minera, considerando variables características de la Teoría Económica Regional. Los resultados muestran la consistencia de los patrones de localización, espe¬cialización e infraestructura productiva como factores explicativos de la eficiencia; asimismo, estos constituyen un referente que explica los factores puntuales a mejorar para elevar los niveles de eficiencia en el aprovechamiento de los diferentes minerales estudiados.

  15. La industria minera en México: patrones de desempeño y determinantes de eficiencia

    Directory of Open Access Journals (Sweden)

    Edgar Gaytán

    2014-01-01

    Full Text Available El propósito del presente artículo es cuantificar y analizar los niveles de eficiencia técnica en la minería no petrolera de México. Se emplea el análisis envolvente de datos (DEA y un modelo econométrico de panel que explora las determinantes de la eficiencia en la operación minera, considerando variables características de la Teoría Económica Regional. Los resultados muestran la consistencia de los patrones de localización, especialización e infraestructura productiva como factores explicativos de la eficiencia; asimismo, estos constituyen un referente que explica los factores puntuales a mejorar para elevar los niveles de eficiencia en el aprovechamiento de los diferentes minerales estudiados.

  16. Condiciones de vida desde el enfoque de los determinantes sociales en salud en un grupo organizado de madres adolescentes

    Directory of Open Access Journals (Sweden)

    Lady Rocío Quimbayo Fandiño

    2012-12-01

    Full Text Available Introducción: Las madres adolescentes que existen en condiciones de vida no adecuadas para su desarrollo presentarán un mayor riesgo de sufrir consecuencias no benéficas para su calidad de vida. El objetivo de esta investigación fue caracterizar las condiciones de vida desde el enfoque de los determinantes sociales en salud en un grupo de madres adolescentes en la Localidad de Suba. Materiales y Métodos: Diseño cuantitativo de tipo descriptivo y aplicación de una encuesta en una muestra intencional de 92 participantes.Fue desarrollado de Enero de 2010 a Junio de 2011. La información fue analizada en el programa estadístico SPSS versión 15. Resultados: En los resultados encontrados se determinó el perfil de la madre adolescentes desde los Determinantes Sociales de la Salud, las jóvenes se caracterizan por ser habitantes de un territorio definido por condiciones de alta vulnerabilidad, con escolaridad promedio: bachillerato, ocupación: estudiantes, amas de casa o desempleadas, es decir sin remuneración económica, estado civil en unión libre o soltera, la tipología familiar nuclear, lo que conlleva a la dependencia económica, la edad de inicio de relaciones sexuales en la adolescencia media (14 a 17 años, con poco uso de métodos anticonceptivos. Afortunadamente, las alteraciones de salud durante la gestación son mínimas y cuidan de la salud en los casos de alguna modificación haciendo uso de los servicios de salud, concluyendo así que las condiciones de vida desde los Determinantes Sociales en Salud, no generaron gran impacto en los mismos resultados de salud. Discusión y Conclusiones: El papel de la enfermera debe estar centrado en los diferentes campos de ejercicio: asistencial comunitario e investigativo, con el fin de que contribuyan al mejoramiento del bienestar de las madres adolescentes, estos papeles se pueden ejecutar desde los Determinantes Sociales de Salud Intermedios en

  17. Five-axis Control Processing Using NC Machine Tools : A Tool Posture Decision Using the Tangent Slope at a Cut Point on a Work

    OpenAIRE

    小島, 龍広; 西田, 知照; 扇谷, 保彦

    2003-01-01

    This report deals with the way to decide tool posture and the way to analytically calculate tool path for the work shape requiring 5-axis control machining. In the tool path calculation, basic equations are derived using the principle that the tangent slope at a cut point on a work and the one at a cutting point on a tool edge are identical. A tool posture decision procedure using the tangent slope at each cut point on a work is proposed for any shape of tool edge. The valid- ity of the way t...

  18. Determinantes sociales de la salud en el embarazo, postparto y maternidad reciente: el impacto de la migración

    Directory of Open Access Journals (Sweden)

    Lígia Moreira Almeida

    2014-05-01

    Full Text Available Esta investigación buscó establecer una interfaz entre Salud Pública y Medicina Social. Su objetivo principal se basó en la evaluación de desigualdades teóricas en el acceso, utilización y calidad del cuidado à la salud materna en madres recientes inmigrantes y su interacción con los determinantes sociales de la salud. El plan de investigación subyacente fue diseñado para explorar determinantes clínicos, individuales y sociales específicos en salud materna (en embarazo y posparto. Otro objetivo específico fue la evaluación del acceso, utilización y calidad de la atención recibida (adecuación y satisfacción de las respuestas ofrecidas por el sistema de salud pública, comparando el estado de salud, las percepciones y necesidades de mujeres inmigrantes y nativas en las mismas condiciones y etapas de la maternidad. Los datos se recogieron en todos los hospitales de referencia y varias asociaciones civiles de Porto, para llegar a la población destinataria: madres recientes procedentes de los países con mayor representación en Portugal (Brasil, países africanos de habla portuguesa y países de Europa del Este, y madres recientes portuguesas (por comparación. Para cumplir los objetivos, fueron realizados tres estudios a partir de datos obtenidos en los orígenes definidos, siguiendo diferentes enfoques y diseños metodológicos (estrategias cualitativas y cuantitativas.

  19. Determinantes microeconómicos del acceso al financiamiento externo de la estructura de capital de empresas del sector industrial

    Directory of Open Access Journals (Sweden)

    Guadalupe Hernández Carmen

    2015-01-01

    Full Text Available El objetivo de este trabajo es analizar, por medio de un modelo econométrico de datos de panel, por efectos fijos y aleatorios, los determinantes microeconómicos del acceso al financiamiento externo que afectan la estructura de capital de las empresas del sector industrial, que cotizaron en la Bolsa Mexicana de Valores (BMV en el periodo 2000-2010, a fin de demostrar que la crisis financiera internacional del 2007 modifica la relación entre dichos determinantes y la estructura de capital, lo que explica los cambios en la política de financiamiento en moneda extranjera que siguieron estas empresas. Los hallazgos muestran que las empresas exportadoras, las emisoras de ADRs (Recibos de depósito americano y las de gran tamaño se financiaron en moneda extranjera antes de la crisis, y después de esta, solo las empresas exportadoras y las emisoras de ADRs, aunque en mayor proporción las empresas exportadoras, lo que muestra que estas, al resolver de mejor forma sus problemas de información asimétrica con sus acreedores, al contar con buenos colaterales en las cuentas por cobrar en moneda extranjera, y dar a los inversionistas una señal positiva de una buena situación económica, lograron continuar financiándose en moneda extranjera a pesar de la crisis. Derechos reservados © 2015 Universidad Nacional Autónoma de México, Facultad de Contaduría y Administración. Este es un artículo de acceso abierto distribuido bajo los términos de la Licencia Creative Commons CC BY-NC-ND 4.0.

  20. Perspectivas teóricas y metodológicas para el estudio del ambiente como determinante de la salud

    Directory of Open Access Journals (Sweden)

    María O. Garzón-Duque

    2016-09-01

    Full Text Available Objetivo: describir algunas de las perspectivas teóricas y metodológicas del ambiente como determinante de la salud, como un aporte desde lo conceptual a este complejo campo en constante construcción y deconstrucción. Metodología: revisión de tema con un análisis de la literatura previa detección y consulta de documentos oficiales y artículos científicos que permitieron la estructuración del texto alrededor del tema. Resultados y discusión: a lo largo de la historia y en los diferentes discursos, vivencias individuales y colectivas, el ambiente ha estado presente en el continuo del proceso salud – enfermedad. La higiene y el saneamiento resuelven el problema en un escenario donde hay riesgos y peligros que deben ser identificados para controlarse o eliminarse. Sin embargo, desde las últimas décadas del siglo XX por intereses económicos, necesidad de conservar la salud, por los daños, problemas ambientales globales y locales, se ha dado lugar, al menos desde lo teórico y metodológico, al entendimiento del ambiente como un determinante de la salud, concepción que implica pasar del dominio y control del hombre sobre la naturaleza a entenderse como parte de ella misma. Conclusiones: a través del tiempo se ha observado y vivenciado que las intervenciones antrópicas del hombre sobre la naturaleza han sido poco respetuosas y ha pasado sistemáticamente de ser victimario de su ambiente y su entorno a ser víctima de los ambientes construidos. Los modelos de salud ambiental construidos con una mirada más desde la salud deben integrarse con otras disciplinas, para el análisis de situaciones complejas en salud ambiental.

  1. Determinismo-indeterminación y el debate de los determinantes-determinación social de la salud / Determinism–indetermination and the debate on determinants- social determination of health

    Directory of Open Access Journals (Sweden)

    Fernando Peñaranda

    2013-08-01

    Full Text Available El debate entre determinantes sociales de la salud o determinación social de la salud, promovido por la medicina social latinoamericana a raíz de la propuesta presentada por la Comisión sobre los Determinantes Sociales de la Salud de la oms, pasa por analizar la tensión entre determinismo e indeterminismo y sus repercusiones para concebir la causalidad desde un punto de vista histórico y epistemológico. Este artículo presenta algunas tendencias sobre la visión cosmológica y epistemológica en la historia del pensamiento occidental que han marcado dicho debate, analizando las tensiones entre posiciones monista/pluralista por un lado y determinista/ indeterminista por el otro, y sus repercusiones sobre la forma de concebir al sujeto y su relación con la naturaleza, así como el papel de la libertad humana, la causalidad y el azar. En las conclusiones se propone una puerta de salida a las tensiones y conflictos analizados desde la dialéctica que permita superar la cosmovisión causal de la realidad, en la cual se dé espacio para la acción del sujeto como agente. The debate between social “determinants” or “determination” of health, fostered by the Latin American Social Medicine movement after the proposal of the WHO Commission on Social Determinants of Health, involves analyzing the tension between determinism and indeterminism as well as its implications for conceiving causality from a historical and epistemological point of view. This paper presents some trends regarding the cosmological and epistemological view in the Western history of thought that have marked this debate. At the same time, it analyzes the tensions between monist / pluralist positions on the one hand, and deterministic / indeterministic on the other. Similarly, it analyzes their impact on the perception of subjects, the subject / nature relationship, and the role of human freedom, causality and randomness. The conclusions discuss a way out of the tensions

  2. High boiling point hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1929-04-29

    A process is given for the production of hydrocarbons of high boiling point, such as lubricating oils, from bituminous substances, such as varieties of coal, shale, or other solid distillable carbonaceous materials. The process consists of treating the initial materials with organic solvents and then subjecting the products extracted from the initial materials, preferably directly, to a reducing treatment in respect to temperature, pressure, and time. The reduction treatment is performed by means of hydrogen under pressure.

  3. [Empirical study on non-point sources pollution based on landscape pattern & ecological processes theory: a case of soil water loss on the Loess Plateau in China].

    Science.gov (United States)

    Suo, An-ning; Wang, Tian-ming; Wang, Hui; Yu, Bo; Ge, Jian-ping

    2006-12-01

    Non-point sources pollution is one of main pollution modes which pollutes the earth surface environment. Aimed at soil water loss (a typical non-point sources pollution problem) on the Losses Plateau in China, the paper applied a landscape patternevaluation method to twelve watersheds of Jinghe River Basin on the Loess Plateau by means of location-weighted landscape contrast index(LCI) and landscape slope index(LSI). The result showed that LSI of farm land, low density grass land, forest land and LCI responded significantly to soil erosion modulus and responded to depth of runoff, while the relationship between these landscape index and runoff variation index and erosion variation index were not statistically significant. This tell us LSI and LWLCI are good indicators of soil water loss and thus have big potential in non-point source pollution risk evaluation.

  4. Putting to point the production process of iodine-131 by dry distillation (Preoperational tests); Puesta a punto el proceso de produccion de yodo-131 por destilacion seca (Pruebas preoperacionales)

    Energy Technology Data Exchange (ETDEWEB)

    Alanis M, J. [ININ, Departamento de Materiales Radiactivos, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2002-12-15

    With the purpose of putting to point the process of production of {sup 131}I, one of the objectives of carrying out the realization of operational tests of the production process of iodine-131, it was of verifying the operation of each one of the following components: heating systems, vacuum system, mechanical system and peripheral equipment that are part of the production process of iodine-131, another of the objectives, was settling down the optimal parameters that were applied in each process during the obtaining of iodine-131, it is necessary to point out that this objective is very important, since the components of the equipment are new and its behavior during the process is different to the equipment where its were carried out the experimental studies. (Author)

  5. Study on the quantitative relationship between Agricultural water and fertilization process and non-point source pollution based on field experiments

    Science.gov (United States)

    Wang, H.; Chen, K.; Wu, Z.; Guan, X.

    2017-12-01

    In recent years, with the prominent of water environment problem and the relative increase of point source pollution governance, especially the agricultural non-point source pollution problem caused by the extensive use of fertilizers and pesticides has become increasingly aroused people's concern and attention. In order to reveal the quantitative relationship between agriculture water and fertilizer and non-point source pollution, on the basis of elm field experiment and combined with agricultural drainage irrigation model, the agricultural irrigation water and the relationship between fertilizer and fertilization scheme and non-point source pollution were analyzed and calculated by field emission intensity index. The results show that the variation of displacement varies greatly under different irrigation conditions. When the irrigation water increased from 22cm to 42cm, the irrigation water increased by 20 cm while the field displacement increased by 11.92 cm, about 66.22% of the added value of irrigation water. Then the irrigation water increased from 42 to 68, irrigation water increased 26 cm, and the field displacement increased by 22.48 cm, accounting for 86.46% of irrigation water. So there is an "inflection point" between the irrigation water amount and field displacement amount. The load intensity increases with the increase of irrigation water and shows a significant power correlation. Under the different irrigation condition, the increase amplitude of load intensity with the increase of irrigation water is different. When the irrigation water is smaller, the load intensity increase relatively less, and when the irrigation water increased to about 42 cm, the load intensity will increase considerably. In addition, there was a positive correlation between the fertilization and load intensity. The load intensity had obvious difference in different fertilization modes even with same fertilization level, in which the fertilizer field unit load intensity

  6. Microbiological performance of Hazard Analysis Critical Control Point (HACCP)-based food safety management systems: A case of Nile perch processing company

    NARCIS (Netherlands)

    Kussaga, J.B.; Luning, P.A.; Tiisekwa, B.P.M.; Jacxsens, L.

    2017-01-01

    This study aimed at giving insight into microbiological safety output of a Hazard Analysis Critical Control Point (HACCP)-based Food Safety Management System (FSMS) of a Nile perch exporting company by using a combined assessment, This study aimed at giving insight into microbiological safety output

  7. Technical note: Discard the specimen collection swab directly at point of care to improve extensive automated processing in clinical microbiology laboratories.

    Science.gov (United States)

    Avolio, Manuela; Grosso, Shamanta; Bruschetta, Graziano; Camporese, Alessandro

    2016-10-01

    We compared, in terms of microorganisms recovery, the discard of specimen collection swab, after swirling into its medium, directly at point of care, with its placing into the medium and vortexing on arrival in the laboratory. Our results show that these two procedures are overlapped in terms of bacterial recovery. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Do Self-Regulated Processes such as Study Strategies and Satisfaction Predict Grade Point Averages for First and Second Generation College Students?

    Science.gov (United States)

    DiBenedetto, Maria K.

    2010-01-01

    The current investigation sought to determine whether self-regulatory variables: "study strategies" and "self-satisfaction" correlate with first and second generation college students' grade point averages, and to determine if these two variables would improve the prediction of their averages if used along with high school grades and SAT scores.…

  9. Fatores determinantes da qualidade das águas superficiais na bacia do Alto Acaraú, Ceará, Brasil Assessment of the surface water quality in the upland of Acaraú watershed, Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Eunice Maia de Andrade

    2007-12-01

    samples were analyzed for pH, temperature, color, electrical conductivity, turbidity, nitrate, ammonia, sodium, chloride, potassium, sulfate, total hardness, calcium, magnesium, total alkalinity, alkalinity bicarbonate, total suspended solids, dissolved oxygen (DO, 5-days biochemical oxygen demand (BOD5, total phosphate, orthophosphate, chlorophyll-a, and feacal coliform. Multivariate statistical techniques, (FA/PCA, allowed the identification of variables that explain the major percent of total variance. Three components were identified as responsible for the data structure, explaining 88% of the total variance of the data set. Model showed that the first factor (39.81% of variance assigned as mineralization factor. The second one (29.22% of variance represented as nutrients group. The third factor (19.16% variance assigned as a combination of agricultural area runoff and weathering. Varimax rotation showed that the mainly water quality parameters were related to mineralization (natural process and non-point pollution (anthropogenic activities.

  10. Movilización social y determinantes sociales de la salud: proceso educativo en comunidad rural de Jalisco, México

    Directory of Open Access Journals (Sweden)

    Jorge Laureano Eugenio

    2015-01-01

    Full Text Available El artículo describe proceso y resultados de trabajo educativo en comunidad rural, sustentado en la educación popular. Ello como estrategia para lograr la movilización social e incidir en los determinantes sociales del contexto. Consistió en cuatro etapas: 1. conocimiento de la comunidad, 2. conformación de grupo primario, 3. movilización social con integración de comisiones de trabajo, 4. crecimiento del proceso con distintas modalidades de participación. El modelo educativo, a tres años de trabajo, ofrece la posibilidad de lograr la movilización social a manera de demanda pública organizada hacia organismos e instituciones de salud, educación y desarrollo social, con el empoderamiento comunitario y fortalecimiento del entramado social para incidir en los determinantes sociales.

  11. Determinantes de la divulgación de información financiera: aplicación de una propuesta para su clasificación

    Directory of Open Access Journals (Sweden)

    Saitua Iriba, Ainhoa

    2008-11-01

    Full Text Available En este trabajo reflexionamos acerca del papel que desempeña el campo de la investigación sobre los factores determinantes del nivel de divulgación de las empresas, para tratar de contribuir a la búsqueda de soluciones que promuevan las mejores condiciones de divulgación por parte de las empresas. Para ello, en el apartado segundo realizamos una propuesta teórica en relación con la dirección que a nuestro juicio debería seguir la investigación sobre los factores determinantes del nivel de divulgación de información. En el apartado tres aplicamos dicha propuesta a un trabajo de revisión de los estudios que se han publicado sobre la materia, y en el último plasmamos nuestras reflexiones finales.

  12. Da noção de determinação social à de determinantes sociais da saúde

    Directory of Open Access Journals (Sweden)

    Júlia Arêas Garbois

    Full Text Available RESUMO O ensaio aborda criticamente a noção de determinantes sociais da saúde, veiculada oficialmente pela Organização Mundial da Saúde, a partir da discussão sobre sua perspectiva conceitual que difere bastante daquela cunhada por volta dos anos 1970, pela corrente médico-social latino-americana, de determinação social da saúde. A discussão desnuda os preceitos filosóficos que sustentam a noção de determinantes sociais da saúde, a partir dos argumentos fundados na sociologia positivista de Émile Durkheim. Conclui-se que essa noção identifica um 'social' fragmentado, trazendo consequências práticas e políticas e mostrando-se insuficiente para analisar as mudanças sociais da contemporaneidade.

  13. Una tipología de empresas latinoamericanas exportadoras de servicios intensivos en conocimiento y los determinantes de su competitividad internacional

    Directory of Open Access Journals (Sweden)

    Andrés Niembro

    2017-01-01

    Full Text Available Este artículo persigue varios objetivos: por un lado, aportar una primera tipología de empresas latinoamericanas exportadoras de servicios intensivos en conocimiento, y por otro, contribuir al estudio de los determinantes de la competitividad internacional en estos sectores, con evidencia de América Latina, indagando además si la influencia de estos factores difiere entre los distintos tipos de empresas. Sobre la base de evidencia exploratoria de un conjunto de empresas latinoamericanas exportadoras de servicios intensivos en conocimiento se recurre al análisis clúster para identificar diferentes patrones empresariales. El reconocimiento de realidades empresariales heterogéneas y la identificación de impactos diferenciales de los determinantes de la competitividad pueden colaborar para un mejor diseño de medidas de política ajustadas a cada contexto.

  14. Determinantes dos arranjos contratuais: o caso da transação produtor-processador de carne bovina no Uruguai

    Directory of Open Access Journals (Sweden)

    Mario Mondelli

    2008-09-01

    Full Text Available Quais os determinantes da escolha do arranjo contratual nas transações entre produtores e processadores de carne bovina? A pergunta problema se insere no estudo dos mecanismos associados à coordenação da produção para dar respostas às preocupações dos consumidores. Observa-se a coexistência de arranjos contratuais nos sistemas produtivos de carne bovina, entre os quais a transação direta entre o pecuarista e o frigorífico, ou via intermediário especializado. A Economia dos Custos de Transação (ECT pode ser utilizada para explicar a escolha dos arranjos contratuais observados, como resposta aos desafios de ganhos de eficiência "economizando" nos custos das transações. O presente estudo focaliza o sistema agroindustrial de carne bovina uruguaio, sendo estruturado em três partes. Primeiro a análise do histórico das relações entre produtores e processadores, e mudanças do ambiente institucional. A seguir, a partir das dimensões da transação (freqüência, especificidade de ativo e incerteza geram-se hipóteses a respeito dos determinantes da escolha dos arranjos contratuais. Finalmente as hipóteses são testadas a partir de um modelo logit. Utiliza-se um painel de dados com a totalidade de transações realizadas entre produtores e processadores fornecidos pelo Ministério de Agricultura do Uruguai (77.000 transações. Os resultados validam estatisticamente as hipóteses levantadas a respeito dos determinantes da escolha do arranjo contratual entre produtores e processadores. Uma transação tem maior probabilidade de se alinhar com o arranjo contratual direto (mais coordenado quanto maior o grau de ativos específicos envolvidos no produto, quanto menor a distância entre o produtor e o processador e quanto maior a freqüência de transações entre as partes envolvidas, corroborando a teoria de ECT.What are the determinants of the commercial channel choice in the beef producers-processors transactions? The question

  15. Determinantes sociales de la exclusión a los servicios de salud y a medicamentos en tres países de América Central

    Directory of Open Access Journals (Sweden)

    Cecilia Acuña

    2014-02-01

    Full Text Available OBJETIVO: Examinar los determinantes sociales que afectan la conducta de la población en relación con la búsqueda y obtención de medicamentos, y su relación con la exclusión de los servicios de salud para datos agregados de tres países de América Central: Guatemala, Honduras y Nicaragua. MÉTODOS: Estudio observacional descriptivo de corte transversal, mediante la aplicación de una encuesta de hogares. La muestra del estudio se seleccionó de acuerdo al método de conglomerados. Los datos fueron analizados con el programa SPSS® V.17, utilizando estadística descriptiva y análisis bivariado, multivariado y por componentes principales (ACP. RESULTADOS: Aunque la mayoría de las personas pudo acceder a la atención en salud, la exclusión en salud (razón de probabilidades [RP] 4,10; intervalo de confianza de 95% [IC95%] fue el principal determinante de la falta de acceso a los medicamentos. Las características de la vivienda (RP 0,747, IC95%, la formalidad del empleo del jefe(a de hogar (RP 0,707, IC95% y las condiciones socioeconómicas del hogar (RP 0,462, IC95% fueron también importantes determinantes de la falta de acceso a los medicamentos. CONCLUSIONES: Los fenómenos de la falta de acceso a servicios de salud y a medicamentos no son independientes entre sí. Se corroboró que el sistema de salud, como determinante social intermediario de la salud, es un factor importante para la mejora del acceso a medicamentos. Las políticas públicas orientadas a alcanzar la cobertura universal deben contemplar esta relación para ser eficaces.

  16. A Fast-Processing Modulation Strategy for Three-Phase Four-Leg Neutral-Point-Clamped Inverter Based on the Circuit-Level Decoupling Concept

    DEFF Research Database (Denmark)

    Ghoreishy, Hoda; Zhang, Zhe; Thomsen, Ole Cornelius

    2012-01-01

    In this paper, a modulation strategy based on the circuit-level decoupling concept is proposed and investigated for the three-level four-leg neutral-point-clamped (NPC) inverter,with the aim of delivering power to all sorts of loads, linear/nonlinear and balanced/unbalanced. By applying the propo......In this paper, a modulation strategy based on the circuit-level decoupling concept is proposed and investigated for the three-level four-leg neutral-point-clamped (NPC) inverter,with the aim of delivering power to all sorts of loads, linear/nonlinear and balanced/unbalanced. By applying...... the proposed modulation strategy, the four-leg NPC inverter can be decoupled into three three-level Buck converters in each defined operating section. This makes the controller design much simpler compared to the conventional four-leg NPC inverter controllers. Also, this technique can be implemented...

  17. Processes governing the mass balance of Chhota Shigri Glacier (western Himalaya, India) assessed by point-scale surface energy balance measurements

    OpenAIRE

    Azam, M. F.; Wagnon, P.; Vincent, C.; Ramanathan, AL.; Favier, V.; Mandal, A.; Pottakkal, J. G.

    2014-01-01

    Some recent studies revealed that Himalayan glaciers were shrinking at an accelerated rate since the beginning of the 21st century. However, the climatic causes for this shrinkage remain unclear given that surface energy balance studies are almost nonexistent in this region. In this study, a point-scale surface energy balance analysis was performed using in situ meteorological data from the ablation zone of Chhota Shigri Glacier over two separate periods (August 2012 to February 2013 and July...

  18. A Study on the Effect of the Contact Point and the Contact Force of a Glass Fiber under End-Face Polishing Process

    Directory of Open Access Journals (Sweden)

    Ying-Chien Tsai

    2015-01-01

    Full Text Available The offset between the center lines of the polished end-face and the fiber core has a significant effect on coupling efficiency. The initial contact point and the contact force are two of the most important parameters that induce the offset. This study proposes an image assistant method to find the initial contact point and a mathematical model to estimate the contact force when fabricating the double-variable-curvature end-face of single mode glass fiber. The repeatability of finding the initial contact point via the vision assistant program is 0.3 μm. Based on the assumption of a large deflection, a mathematical model is developed to study the relationship between the contact force and the displacement of the lapping film. In order to verify the feasibility of the mathematical model, experiments, as well as DEFORM simulations, are carried out. The results show that the contact forces are alomst linearly proportional to the feed amounts of the lapping film and the errors are less than 9%. By using the method developed in this study, the offset between the grinding end-face and the center line of the fiber core is within 0.15 to 0.35 μm.

  19. Determinantes de la calidad de vida relacionada con la salud de pacientes en diálisis de Uruguay.

    Directory of Open Access Journals (Sweden)

    Ana I Galain

    2014-12-01

    Full Text Available Existen pocos estudios sobre la percepción subjetiva de la calidad de vida relacionada con la salud en pacientes renales cursando su etapa terminal, que vivan en países no industrializados. El propósito de este estudio fue comprender las relaciones subyacentes entre los diferentes determinantes de la calidad de vida relacionada con la salud, en los pacientes en tratamiento sustitutivo renal en Uruguay. Se realizó un estudio transversal en una muestra de 243 pacientes de cinco centros de hemodiálisis y diálisis peritoneal de la ciudad de Montevideo (edad media de 56,6 años, SD 16,2; 58% hombres. Se realizó un análisis de regresión lineal univariado para cada variable independiente. Se incluyó un total de 61 variables independientes biológicas/clínicas, sociodemográficas y psicosociales. La CVRS fue evaluada utilizando el cuestionario SF-36, que consta de ocho subescalas, más el Componente de Resumen Físico (PCS y el Componente de Resumen Mental (MCS. Aquellas variables que mostraron una asociación significativa en el análisis univariado (p< 0,10 fueron incluidas en un análisis de regresión multivariado. Fueron estudiados diez modelos de regresión, para las 8 subescalas del SF-36, el PCS y MCS. Quince variables fueron significativas en los modelos multivariados: tiempo en tratamiento sustitutivo renal, urea, creatinina, hemoglobina, hierro hospitalizaciones, enfermedades agudas, ceguera, edad, género, vivir con alguien, situación laboral, administración de antidepresivos o de antipsicóticos y mantenimiento de la vida sexual; explicando el 43% de la varianza de PCS y el 35% de MCS. El tipo y relevancia de las variables explicativas difieren a lo largo de las diversas dimensiones de la CVRS. Destacamos como conclusión el entrelazamiento de factores biológicos, sociodemográficos y psicosociales como determinantes de la calidad de vida relacionada con la salud en los pacientes renales cursando su etapa terminal, lo que

  20. VARIÁVEIS DETERMINANTES DA PRECIFICAÇÃO BASEADA NO VALOR PARA O CONSUMIDOR EM INSTITUIÇÕES DE ENSINO SUPERIOR PRIVADA

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    Marlei Mecca

    2005-06-01

    Full Text Available Instituições de ensino superior privadas precisam avaliar os fatores críticos considerados pelos acadêmicos no momento da escolha da instituição, bem como monitorar as variáveis estratégicas determinantes no processo de satisfação dos consumidores. Assim, o  artigo identifica as variáveis determinantes da precificação baseada no valor entregue ao consumidor em instituições de ensino superior privadas. Para tanto, realizou -se um estudo descritivo, por meio de uma pesquisa em  três instituições de ensino superior privadas. Para a coleta dos dados utilizou-se um questionário fechado, a fim de identificar os fatores determinantes da precificação fundamentada no valor para o consumidor, segundo o modelo de Philip Kotler. Os resultados da pesquisa mostram que as principais variáveis de valor total para o consumidor são a   qualificação do corpo docente, qualidade do curso, retorno dos investimentos e adequação dos recursos físicos. Entre as variáveis de custo total para o consumidor foram apontados os horários de aulas, o tempo e custo  com deslocamento, valor da mensalidade, as  atividades complementares e a carga horária do curso.